SECTICIDES, FUNGICIDES
AND WEEDKILLERS

E.BOURCART, D.S

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U.B.C. LIBRARY

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• INSECTICIDES, FUNGICIDES, AND
WEEDKILLERS

INSECTICIDES, FUNGICIDES
AND WEEDKILLERS

A PRACTICAL MANUAL ON THE DISEASES OF
PLANTS AND THEIR REMEDIES, FOR THE USE OF
MANUFACTURING CHEMISTS, AGRICULTURISTS,
ARBORICULTURISTS AND HORTICULTURISTS

E. BOURCART, D.Sc.

TRANSLATED FROM THE FRENCH, REVISED AND
ADAPTED TO BRITISH STANDARDS AND PRACTICE

BY

DONALD GRANT

WITH EIGHTY-THREE TABLES AND TWELVE ILLUSTRATIONS

LONDON
SCOTT, GREENWOOD & SON

8 BROADWAY, LUDGATE, E.C.
'[The sole rights of translatiun into English remain with Scott, Greemvood <St* Son'\

Digitized by the Internet Archive

in 2010 with funding from

University of British Columbia Library

http://www.archive.org/details/insecticidesfunOObour

AUTHOR'S PREFACE.

Every year the diseases of plants become more numerous, their
economic importance increases, and the number of those in-
terested becomes greater; more numerous by the means of
communication estabHshed between different countries, and by
more frequent commercial intercourse ; more important and
more dangerous because they prevent the heavy yields of dif-
ferent crops which should be obtained from the high farming
with which the prosperity of our farmers is so closely associated ;
the number of those interested increases because gardening for
pleasure, ornamental horticulture, extends daily more and more
amongst all classes of society. It therefore becomes indispens-
able that the farmer, the gardener, and the amateur flower
grower should possess a treatise in which they can easily find
the cause of the diseases which dishearten them, and at the
same time an efficient remedy capable of circumscribing them
and of preventing their return.

So as to render this treatise complete in itself it was deemed
necessary to pass in review the numerous experiments made up
to now to suppress and prevent plant diseases.

The author has striven from the aggregate of the results
reported to frame certain scientific rules which appear to deter-
mine the success of certain classical methods and to explain
certain notorious failures, rules which may serve as a useful
guide to future experiment and aid in the discovery of new pro-
ducts of greater efficiency than those now at our disposal.

The preventive and combative treatment of the diseases of
plants requires a profound knowledge of the parasite as well as
the product used as a remedy. Success depends on the judicious
choice of the remedy utilized and the manner in which it is
applied.

The plan of this book is therefore conceived in such a way

Vl AUTHORS PREFACE.

as to enable the less initiated to find with the greatest ease the
information which they require when they desire to treat a
diseased plant.

The author has annexed to the book a glossary of the prin-
cipal diseases of plants and the parasites which occasion them.
The descriptions given therein afford the requisite information
as to the different states of evolution of the parasites whilst they
are vulnerable, because such knowledge is indispensable to form
a decision as regards the periods at which it may be desirable
to apply the effective remedies preventively and curatively.

In the index, after the name of the cultivated plant, there
follows a list of the diseases from which it may suffer. It suf-
fices to turn to the glossary when the reader does not know the
cause of any disease, and the name of the disease being identi-
fied to find in the index the page where its treatment is de-
scribed.

The author's object will be attained if this book serves as a
guide to those who have sought most often in vain a means of
restoring health to plants which form the object of their care or
the joy of their leisure.

E. BOUECAET.

Paris, 1911.

TRANSLATOE'S PEEFACE.

Dr. Bourcart has done his work so well that the translator
would fail in his duty if he did not insist on one point on which
the author is silent, viz., the enormous value of the great
number of tried recipes — recipes which have passed the ordeal
of a capable and wise censorship — embodied in this treatise to
every one interested, whether farmer, gardener, forester or last
but possibly not least the manufacturing chemist. But the
reader will soon discover for himself that this is not the only
feature which renders the book unique of its kind.

DONALD GEANT.

London, November, 1912.

TABLE OF CONTENTS.

INTRODUCTION.

PAGE

Relative and absolute diseases |

Etiology ,

Physical causes of disease

Chemical causes of disease

Parasitic causes of disease -

Symbiosis -- „.

Antagonistic symbiosis - '

Mutual istic symbiosis -----

Therapeutics - g

Surgical treatment '""'"'"'fi

Vegetable surgery '"""," u j 7

Methods of destroying parasites by the naked hand ^

Picking and catching „

Traps and baits - „

Chemical treatment - - - „

Curative treatment '""'"""'""«

Anti-cr>'ptogamic substances or fungicides ^

Examination of curative agents

Action of chemical products on parasites °

Action of chemical products on plants

Liquid products ----

Gaseous products - ---" 1q

Indispensable properties of the chemical agents - - " , " . ' ' ^^

Methods of using chemical products in treating the diseases of plants - - XJ-

Underground treatment - - ,,

Aerial or above-ground treatment by gases ^^^

Clochage ' " " -19

Scalding or treatment by boiling -water ^

Use of chemical agents in the form of powder t^_^

Use of chemical agents in the liquid form ^-^

External treatment -.------■' '

Internal treatment -------■""

Prophylaxy ] 15

Therapeutic prophylaxy - - 15

Preventive surgical treatments " ' ' 16

Preventive treatment by means of chemical agents ' ' ' ' ' 17

Preventive summer treatment ----'"'" - „

Hygienic prophylaxy ' ' - 18

Growth stimulants

Nutrition

Exhaustion of the soil -

18
19
20

Choice of species -------"'" - 20

Meteorological influences - - - - ' • ■, a 91 92

United efforts to exterminate injurious insects, fungi, and weeas -

vii

Vlll TABLE OF CONTENTS.

CHAPTER I.

Watbb, Hot and Cold — Submersion or Field, Forest, and Vineyard — Scalding —

Hydrogen Peroxide.

PAGE

1. Water, H2O - - ^ 23-24

Use 23

Cold Water.

SubmerBion of fields and meadows ....... 24

Submersion of forests 24

Anti-phylloxeric submersion 25

Submersion in actual practice 26

A. Winter submersion ......... 27

B. Submersion during the active period of the vine - - . - 27-30
Spraying 30

Hot Water.

Resistance of insects to heat --------- 31

Resistance of seed to heat -...----.31

Resistance of fungi to heat - 31

Action of dry and moist heat on seeds and spores 31

Use of hot water 32

Hot-water steeping of seed-corn to kill disease spores - - - . 32-36

Immersion of seed against insects, phylloxera 36

Hot-water spraying against cochylis, etc. - 37-40

2. Hydrogen Peroxide, H0O2 - - 40

Preparation - - - 40

Properties 40

Use - 40

CHAPTER II.

Hydrogen Sulphide — Sulphur.

3. Hydrogen Sulphide (sulphuretted hydrogen, HjS) 41-2

Preparation ------------ 41

Properties - - - - - - - - - - - - 41

Action on plants 41

Action on insects ----------- 41

Use 42

4. Sulphur, S.

Preparation ------------ 42-4

Use 44

How does sulphur act ? 44

How should sulphur be applied ? 46

The regulator sulphur bellows (illustrated) 47

The torpedo sulphur distributor 47

Use against bacteria (potato scab, etc.) ------- 47

Use against fungi (rusts and mildews) 48-50

Drawbacks to sulphuring - - . - 50

Use of sulphur against insects -------- 52

Use against acari 53

CHAPTER III.

Carbon Disulphiue, CS.^.

6. Caiuion Dihulpiiide, CSj - - - 54

J'reparation ----- 54

Properties ........... 54.

Action of carbon disulphide on plants - - 55

TABLE OF CONTENTS. IX

PAGE

Action of carbon disulphide on insects 56

Action on fungi - . . . - 57

Influence on fertility of soil 57-9

Use 59-77

History 59

Vaselinated sulphide 61-2

Instruments for applying carbon disulphide 62

Pal-gastine ------------ 62

Avant-pal 62

Pal-excelsior ...-.-.---- 62-3

Sulphurators - - 63

Disinfection in closed spaces - - - - 63

Destruction of aerial parasites ..--.--. 64

Use against cryptogamic diseases 64

Use against eel-worms -- - - - - - - - -65

Use against insects - ' 65-71

Underground disinfection .-.------ 71

Extermination treatment ...-.---. 71

■Cropping treatment 72

Use of pure carbon disulphide 72

Use of carbon disulphide dissolved in water ------ 74

Insecticide irrigations ---------- 75

CHAPTER IV.

'SuLPHOBOus Acid — Sulphuric Acid (Oil of Vitriol) — Chlorine — Hydrochloric

Acid — Nitric Acid.

6. Sulphurous Acid, SOj - - 78

Properties - - 78

Action on plants 78-80

Action on fungi ----------- 80

Action on insects - - - - - - - -. - - - 80

Us 9 in diseases treated by SOj in the open air - . - . . 80

Use in closed spaces - - - - - - - - - - 80

7. Sulphuric Acid, H^SO^.

Natural occurrence 83

Properties ..-.-.-----. S3

Action on plants --83

Action on fungi ----------- 83-8

Use as pickle for seed-corn --------- 83-6

Use as weedkiller ----------- 85

Use against insects and eel-worms ------- 88

Use against wasps ----------- 88

8. Chlorine, Cl.^.

Preparation ------------88

Use against dry rot 88

9. Hydrochloric Acid, HCl.

Preparation 88

Use 88

Action of chlorine and hydrochloric acid on plants ----- 89

10. Nitric Acid, HNO3.

Preparation ------ - 90

Properties . . . - 90

Action on plants - - - - . - - - - - - - 90

Use 90

Use against fungi -.--------- 90

Use against insects -..------- 90-1

X TABLE OF CONTENTS.

CHAPTER V.

Phosphorus — Phosphoretted Hydrogen — Arseniuretted Hydrogen — Arsenious
Sulphide — Arsenious Acid — White Arsenic — Arsenic Acid — Boric Acid.

PAGE

11. Phosphorus, P. ------- --.-92

Preparation ----.----..- 92

Properties ---92

Use 92

12. Phosphoretted Hydrogen, PHj.

Preparation -----------.93

Properties - 93

Use 93

13. Arseniuretted Hydrogen, AbHj.

Preparation 93

Properties 98

Use - - 93

14. Arsenious Sulphide, ASgSg.

Use 94

15. Arsenious Acid, A82O3.

Manufacture -- 94

Properties 94

Use 94

Use against insects - -. 95

Use against rodents 9&

16. Arsenic Acid, A82O5.

Preparation -97

Properties - - - 97

Use 97

Use as pickle for seed-corn 97

17. Boric Acid, B3O3.

Preparation --------- . - - 97

Properties 97

Use . 97

CHAPTER VI.

Ammonia — Ammonium Sulphide — Ammonium Sulphocyanide — Ammonium Sulphate
— Ammonium Carbonate — Sodium Hyposulphite — Sodium Sulphate — Sodium
Chloride (Common Salt) — Sodium Nitrate (Chili Saltpetre) — Arsenite of
Soda — Borax — Sodium Carbonate.

18. Ammonia, NH, 98-

Preparation - - 98

Properties - 98

Use 98-9

19. AmmoiJiuji Sulphide (NH4)2S.

Preparation 99

Properties - . . - 99

Use - - 99-lOa

20. Ammonium Sulphocyanide, NH4CNS.

Preparation - 100

Properties 10ft

Use 100

21. Ammonium Sulphate (NHJjSO^.

Manufacture ------.----- 100

Properties --.-.--.---- 100

Use 100-1

22. Ammonium Carbonate (NH4)2C03.

Manufacture - 101

Properties 101

Use - - ... ^ 101

TABLE OF CONTENTS. XI

PAGE

23. Sodium Hyposulphite, NaaSaO-SHsO.

Preparation Vl'Z

Properties - - " ' ino

Action on plants |^^

Action on fungi " ' yr!^

Crouzel's anti-cryptoganiic ■^"*'

24. Sodium Sulphate, NaaSOj.

Occurrence - ' ' ' lo'-i

Preparation

Properties

Use - - - - " " 10^

Use as pickle for seed-corn - - auo

25. Sodium Chloride (common salt), NaCl.

Occurrence --- in-i

Properties - - - „_

Kole as manure lOfi

Use as weedkiller - - jj^g

Use to destroy moss jr^

Use against potato diseases jjj^

Use against insects

Use to preserve green fodder during winter -l"'

26. NiTEATE OF Soda, NaNOg.

Occurrence - - - - - - " " ' ' " 'inft

Properties ^„„

Action on plants - - 108

Action on fungi ' " ' " ^^^

Action on insects --- .-- • '""lOft
Use as weedkiller

27. Arsenite of Soda, Na4As205. _

Use as pickle for seed-corn "^

Use in preparations to kill locusts

28. Borax, Na2B407. ^^o

Occurrence - - - - - - " " ' ' " " lOQ

Preparation - - ' " ' inQ

Properties - IIO

Use

29. Carbonate of Soda, NagCOg. ^-^

Preparation ------ '

Properties - - - - - - " ' ' ' ' 'no.

Action on plants - - - - ^..„

Action on fungi ^^

Action on insects iinil

Use

CHAPTER Vn.

Potassium Hydroxide (Caustic Potash)— Potassium Sulphides (Liver of Sulphur).
—Potassium Chloride (Muriate of Potash)— Potassium Nitrate— Potassium
Sulphocarbonate— Potassium Xanthogenate— Potassium Cyanide (Prussic-

AciD).r-P01ASSIU.M SULPHOCYANIDE.

30. Caustic Potash, KHO - ^^t,

Properties - no

Use .----------"■ ^

31. Potassium Sulphides, KjS to KjSg.

Liver of sulphur - - " ' 1 1 h

Properties - - - - - - " ' " " 1 1 S

Use lU

Use against bacteria - - ' ' 1 1 4

Use against fungi - - - -'

Xll TABLE OP CONTENTS.

c, ■ . -, PAGE

bteepmg of seed-corn 114

Spraying with dilute solutions 115-6

Use against insects - - . - - - - . . 116-7

32. Potassium Chloride (muriate of potash), KCl ; Potassium Sulphate, K2SO4.

Natural occurrence - - - - - - - . . -117

Properties -.-... 118

Action on plants 118

Use 118-120

Use as weedkiller --.--..... ng

Use as pickle for seed-corn 119

Use against dodder . 119

Use against meadow horsetail 119

Use against insects 120

33. Nitrate of Potash, KNO3.

OccuiTence -------..... 12O

Preparation -------.... . 120

Properties ------...... 120

Action on plants 120

Action on fungi ---........ 120

Action on spores ----..-.... 121

Use against insects ----...... 121

34. Carbonate of Potash, KgCOj.

Preparation 121

Properties -... 121

Action on plants - - 121

Action on fungi ---.... .... 122

Action on insects 122

35. Potassium Sulphocarbonate, KjCSjHjO.

Preparation --.. 123

Properties .- 123

Action on plants 123

Action on fungi --.-.-..... 124

Action on insects - - - . 124

Use 126-9

Disinfection of vines and graft-bearers by 129

36. Xanthogenate of Potassium, C2HBOCSSK. /

Definition 129

Preparation 129

Properties 129

Use 129

37. Potassium Cyanide, KCN.

Preparation 130

Properties -- 130

Rapid toxic action - - .-...-.. 131

Action on plants 131

Trials on healthy vines 131

Trials as a weedkiller - - . 132

Action on fungi 132

Action on insects - - 132

Use - 133

Cyaniding of trees 133

Use against insects - - - - - - - - - - 134

Fumigating vines 134

Disinfection of vines - - 136

38. I'OTASSIUM SULPHOCYANIDE, KCNS.

Preparation - - 136

Properties -..-. 136

Action on plants ---.....-.. 136

Trials as a weedkiller 135

Trials on healthy vines in pot - 137

Action on fungi ........... 137

Action on insects - - - - - ^ 137

TABLE OF CONTENTS. XUl

CHAPTER VIII.

Barium Chloride — Barium Sulphate — Barium Carbonate — Barium Sulphocar-
BONATE — Calcium Oxide (Quicklime) — Calcium Sulphide — Calcium Chloride
— Calcium Chloro-hypochlorite (Bleaching Powder) — Calcium Sulphate^ —
(Gypsum Plaster of Paris) — Calcium Sulphite — Calcium Carbide — Calcium
Phosphide — Calcium Absenite.

page

39. Barium Chloride, BaClg 138

Preparation - - 133

Properties - 138

Action of plants ........... igg

Action of insects 138

Use against plant diseases ..-...-.. 133
Use against insects - - - - - - - - . . 138-9

Use against rodents .......... 139

40. Barium Sulphate, BaS04.

Use - - - - 139

41. Barium Carbonate, BaCOg.

Preparation I39

Properties 139

Use against rodents . . , I39

42. Barium Sulphocarbonate, BaCSj.

Preparation 139

Properties I39

Use - - 139

43. Calcium Oxide (Quicklime), CaO.

Occurrence ............ 139

Preparation ..---..-.... 140

Properties 140

Use as manure -.-.-...... 14Q

Action on plants .....-.-.-. 141

Use against fungi -.....--... 142

Use against gummosis of stone fruit trees ...... 143

Use against nematodes - - - - . - . - . . 143

Use against insects - - 144

Liming of trees 145

Use against mammals --........ 148

Use against late frosts 148

44. Calcium Monosulphide.

Preparation 148

Properties ............ 148

Action on plants -....-.-... 149

Action on fungi - . . . 149

Action on insects -.-...-.... 149

Uses - - - 149

Use as weedkiller ........... 150

Use against fungi - - 150

Use against insects - - 151

45. Calcium Chloride, CaCl2.

Preparation 152

Properties 153

Use 153

Use as weedkiller 153

46. Chloride of Lime (bleaching powder), CaCljO.

Preparation 153

Properties 153

Use -' 1.33

Use as -weedkiller -- 1.53

Use against insects 153-4

47. Sulphate of Lime (gypsum), CaS04.

Occurrence - 154

XIV TABLiS OP CONTENTS.

PAGE

Properties ---.--...... 154

Action on insects ---------- . 154

Use as a manure -- 154-6

Use against late frosts ---------- 156

Use against fungi - - -----..-. 156

Use against insects - - - . 156-7

Use against snails and slugs 157

Use against rodents --.-..--.- 157
47a. Splphite of Lime, CaS032H20.

Preparation ----- 157

(Bi-sulphite of lime 157)

Use 157

Use against vine rot 157

Use in dairies -- 157

Use in breweries ----------- 157

48. Calciuji Carbide, CaCj.

Preparation 157

Properties .-. I57

Use 157

49. Calcium Phosphide, Ca3P.^.

Preparation --- 157

Use 158

50. Arsenite of Lime, Ca2AB205.

Preparation --- 158

Properties 158

Use 158

CHAPTER IX.

Maonesittm Chloride — Magnesium Sulphate (Epsom Salts) — Magnesium Bisul-
phite— Magnesium Silicate (Talc Soapstone) — Alum — Aluminium Silicate
(China Clay) — Zinc Sulphide — Zmc Chloride — Zinc Sulphate — Zinc Borate
— Zinc Silicate — Zinc Ferrocyanide — Zinc Sulphocarbolate — Cadmium
Sulphate.

51. Magnesium Chloride, MgClj 159

Occurrence ---.----.--- 159

Preparation ------------ 159

Properties 159

Action on plants 159

Trials as a weedkiller ---------- 160-1

Trials as a pickle for seed-corn - - - 161

Use as weedkiller . . - . I6I

Use against charlock in corn crops ------- 161

Use in pine nurseries against yellow leaf of pine 161

52. Magnesium Sulphate (Epsom salts), MgS047HjO.

Preparation ------- 161

Properties . - - 161

Use 161

Use to disinfect beet seed ----.---. 161-2

53. Magnesium Bisulphite, MgH2(S03)2.

Preparation - 162

Use 162

54. Silicates of Magnesia.

Occurrence ------------ 162

Use 162

55. Alum, A1jj.H(S04)K2S04, 24H.p.

Preparation -------.---- 163

Properties -.-- 163

Action on plants 163

Action on fungi --..----.-. 163

TABLE OF CONTENTS. XV

pa(;e

Action on insects 163

Use 163

56. Silicate of Alumina (china clay).

Occurrence ------------ 164

Properties - - - - - . . 164

Use 164

Use against insects .-..------ 164

Use against rabbits 164

57. Zinc Sulphide, ZnS.

Preparation 164

Properties ------------ 164

Use 164

58. Zinc Chloride, ZnClg.

Preparation ------------ 165

Properties ------------ 165

Action on fungi ----------- 165

Trial as pickle for seed-corn 165

59. Zinc Sulphate, ZnSOJHjO (white copperas, white vitriol).

Preparation ------------ 165

Properties .--- 165

Action on plants 165

Stimulating action of minimum doses 165-6

Action on cryptogamic parasites 166

Use 166

60. Borate of Zinc, ZnB407.

Preparation ------------ 166

Use as bouillie for oats and wheat - - 166-7

Use against fungi 167

61. Silicate of Zinc 167

62. Zinc Ferroctanide 167

63. SuLPHocARBOLATE OF ZiNC (zluc Bulpho-phenats) 167

64. Cadmium Sulphate, CdS044H20.

Preparation 167

Properties 167

Use 167

CHAPTEE X.

Iron Peroxide — Iron Bouillies — Iron Sulphide — Iron Chloride — Green Vitriol
— Ferric Sulphate — Potassium Ferroctanide— Prussian Blue — Borate of
Iron.

65. Ferric Hydrate, Fe2(HO)6. 168

Preparation ------------ 168

Bouillies 168

Properties ------------ 168

Action on plants ----------- 168

Pellegrini's bouillie 169

Aderhold's bouillie 169

Sorauer's bouillie ----------- 169

Failure of ferric bouillies 169

Mixed cupric and ferric bouillies -------- 169

66. Sulphide of Iron (ferrous sulphide), FeSj.

Preparation 169-70

Properties 170

Use 170

67. Iron Chloride, Fe2Cl55H20.

Preparation ------------ 170

Properties -- 170

Use 170

Use as pickle for seed-corn 170

Use against chlorosis - - - - ------ 170

XVI TABLE OF CONTENTS.

68. Sulphate of Iron (green vitriol), FeS047H20.

Manufacture 171

Properties ----.-.... .. 171

Action on plants -----...... 171.4

Action on fungi ---........ 174

Comparative action of blue and green vitriol on spores - - - . 174-5

Action on insects I75

Use - - 175

Use against chlorosis -----..... 175

Use as a weedkiller 17g

Destruction of moss 177-8

On meadows and lawns -----... 177-8

On trees - - 173

On roofs -- 178

Destruction of dodder - - . . 173

Use against plant diseases 178-9

Application of greea vitriol to the soil - - 179

Use on aerial part of plant -----... 180-1

(a) As spray 180

(6) As a coating 180-1

Use as an injection in the trunk ----.... 131
Use against cryptogamic diseases of plants - - - - - - 182

Use against potato scab 182

Use against potato disease 182

Use as a pickle for seed-corn - 183-4, 185

Use against grape rot - - 185-6

Use against insects --....... 186-7

69. Ferric Sulphate, Fe2(S04)3.

Preparation --------.-.. 187

Properties -.. 137

Use 187

70. Ferrocyanide or Potassium, K4FeCyg.

Preparation --- 187

Use 187

Action on plants ----- 188

71. Prussian Blue (ferric ferrocyanide), FeyCy^g.

Discovery ------..-..- I88

Preparation -.- 188

Use 188

Trial as pickle for seed-corn 188

Trial as spray for growing oats and summer wheat and pear-trees - - 188

72. Borate of Iron, FeB^O^.

Preparation ------.----. 188

Properties 188

Use 188

Formula for bouillie 188

Trial of such against leaf spots of pear-tree and chestnut-tree - - 188

CHAPTEE XI.

Potassium Bichromate (Bichuome) — Chrome Alum — Potassium Permanganate —
Manganese Sulphate — Nickel Sulphate — Cobalt Sulphate.

( Tii. Potassium Bichromate, K.iCr.O, - - - 189

( 74. Chrome Alum, KaS04Cr.j(SOj..24HaO 189

Preparation -- 189

Properties ............ 189

Action of chrome salts on plants -------- 189

Action on parasitic fungi ......--- 189

TABLE OF CONTENTS. XVll

PAGE

Trial as pickle for seed-corn - - - 189-90

Action on uredospores --------- 189-90

Use against fungi ----------- 190

Use against insects -..--..--- 190

75. Permanganate or Potash, KMnO^.

Preparation ------------ 190

Properties ----------- - 190

Action on fungi 190, 191, 192

. Use as pickle for seed-corn --------- 190

Use as a disinfectant ------- ... 190

Disinfection of trees - - 192

Use against conifer disease .....---- 192

76. Manganese Sulphate, MnSO^SH^G.

Preparation -- 192

Properties . - - - 192

Stimulating action of minute doses of manganese salts on plants - - 192-3
Use against fungi ----------- 193

77. Nickel Sulphate, NiS047H„0.

Preparation ------ - 193

Properties ------------ 198

Stimulating action of minimum doses on plants ----- 193

Action on parasitic fungi ..---.--. 193

Use against fungi ---.------- 193

Use against grey rot of the vine - 194

78. Cobalt Sulphate, CoSOJHaO.

Stimulating action of minimum doses on plants ----- 194
Action on parasitic fungi -..--.--. 194

CHAPTER XII.

Red Lead— Lead Arseniate — Lead Absenite — Lead Carbonate (White Lead) —
Lead Acetate (Sugar of Lead) — Silver Nitrate (Lunab Caustic) — Silver
Chloride.

79. Red Lead, PbgO^ 195

Preparation -..--------- 195

Properties ------------ 195

Use 195

Use to protect seed-corn against birds ..---.- 195

Use to preserve pine and spruce fir seeds from birds .... 195

80. Arseniate of Lead, PbgAsjOg.

Preparation -- 195

Properties - - - ......... 195

Action on plants .-.------.- 195

Action on insects ----------- 195

" Disparin," composition of -------- - 196

Use against insects .......... 196

Bouillies 196

81. Lead Ausenite, PbAs.^0^.

Preparation - . - - . 197

Properties 197

82. Lead Carbonate.

Use 197

83. Lead Acetate, Pb(C2H302)2, SHjO.

Preparation 197

Properties - 197

Action of lead salts on plants . - - ..... 197

Action on parasitic fungi ......... 197

Trial 8 B pickle for seed-corn - 197

Bouillie with milk of lime - 197

b

XVlll TABLE OF CONTENTS.

PAGE

84. Nitrate of Silver, AgNOg.

Preparation ---------... 197

Properties -----.--.... 193

Action on plants ------..-.. igg

Action on fungi . . . 198

Action on spores ----- - igg

Use - - - - 198

85. Silver Chloride, AgCl.

Preparation ------------ igg

Properties -.. igg

Use 198

"Puknos," composition of -----.... 193

Use against cryptogamic diseases in general ------ 193

CHAPTEE XIII.

Copper Sulphide — Copper Nitrate — -Copper Chloride — Copper Sulphite —
Copper Sulphate (Blue Vitriol).

86. Copper Sulphide, CuS.

Preparation ------.--.-. 199

Properties -- -..-. 199

Use - - 199-200

Use as bouillies 199-200

Guillon's formula ----------- 200

87. Copper Nitrate, Cu(N03)o3H20.

Preparation ------..--.. 200

Properties ------------ 200

Use 200

Use as a pickle for seed-corn --------- 200

Use as weedkiller 200

88. Copper Chloride, CuCl22H„0.

Preparation ------ 200

Properties ------ 2OO

Use 200-1

Use as a pickle for seed-corn - ------- -200-1

Recipes for bouillies --.--....- 201

89. Copper Sulphite, CuSO^.

Preparation of bouillie ---------- 201

Properties ---.-..---.- 201

Action on plants - - - - - - -- - - - 201

Action on fungi --.--..--.. 201

90. Sulphate ob' Copper (blue vitriol, blue copperas), CuSOjSHoO.

Preparation ------------ 201

Properties .---.-...-. 201-2

Toxic etfect of copper salts on human subjects ----- 202

Verdigris woikers immune to antemia ------- 202

Distribution of insecticidal and anti-cryptogamic copper between wine,

lees, etc. (table) 203

Action on plants -.-.--.-.- 203-7

Action on alga; and saprophytic fungi ------ 207-8

Action on parasitic fungi ..--..-- 208-11

Use as pickle for seed-corn ------- 208-11, 217-24

Action on insects ---------- 210-11

Use as a weedkiller ---...--.- 211
Use to destroy dodder -----.---- 211

Use against mosses and lichens -...---- 211

Use against cryptogamic diseases of plants ----- 211-13

Use of mixtures containing blue vitriol 214-15

TABLE OF CONTENTS. XIX

PAGE

Composition of proprietary mixtures in powder for making bouillies, or to
be spread with a bellows in a dry state : —

"Poudre Coif,'net" 216

"Sulfatine" ------ 216

" Kupferschwefelkalk ---------- 216

Bouillie bordelaise in a single powder ------ 216

" Skavinsky's powder "--------. 216

" Skavinsky's sulphur ''--------- 216

" Kupfer Klebekalkmehl " - - - 216

" Kupferzuckerkalkpulver " -------- 216

" Cuprocalcit " . . - . - 216

" Cupreina ------------ 216

"Oocidine" - - - 216

Composition of powders to be diluted with water and used exclusively as

bouillies ---------- 216-7

" Parasiticine " ---------- 216

" Antimildioidium " --------- 216

" Poudre Crochepeyre ---------- 216

" Gelatinous cupric hydrocarbonat'j " - - - . - - - 216

" Bouillie d'Azur " --------- 216

"Poudre Eclair" - 216

'• Fostitebriihe " - - 216

" Krystallazurin ----------- 217

" Kupferpreparat Gmund " -------- 217

"Kupfer soda" ..-------. 217

Use against root rot of vine --------- 224

Use against black rot of grapes -------- 224

Use against beet diseases --------- 225

Use against worms and snails ------- 225-6

CHAPTER XIV.

Copper Hydrate— Bouillie Bordelaise — Bouillie Bourguignonne.

91. Copper Hydrate ----------- 227

Preparation of normal bouillie bordelaise ------ 227

Specifications for raw material -------- 227

1. Blue vitriol - - - - 227

2. Milk of lime --------- 227-8

Properties of copper hydrate --------- 228

Properties of bouillie bordelaise -------- 228

Tests to which it should respond -------- 228

Action of cupric hydrate on plants ------ 229-32

Stimulating action of infinitesimal doses of copper - - - 231-2

Action on fresh-water algae --------- 232

Action on fungi ----------- 232

Action of bouillie bordelaise --------- 232-3

Use of bouillie bordelaise -------- 233-60

History of bouillie bordelaise -------- 233

Practical spraying (illustrated) ------- 234-7

Use against mosses and lichens -------- 237

Use against bacterian diseases of plants ------ 237

Use against parasitic myxomycetes ------- 237

Use against parasitic fungi . - - ----- 237-8

Use against potato disease --------- 238

Treating the tubers --------- 238

Treatment of the stems - - -38

Effect of treatment on weight and| starch-content of crop, and per-
centage of diseased potatoes ------- 239

XX TABLE OF CONTENTS.

PAGE

Cost of treatment . . . . 240

Time for spraying ---------- 240

Experimental data - - - _ - - - - - - 239-41

Use against vine diseases - - - - - - - - 242-3

Use against beet diseases ----..--. 243

Use against lettuce disease --------- 244

Use against mildew of the onion -------- 244

Use against cucumber disease -------- 244

Spraying against smut, bunt, and rust of cereals - - - - 245-6

Use against juniper disease --------- 246

Use against leaf curl of the peach - 246-7

Use against oidium of the vine ------- 248-50

Use against black rot of grapes ------- 250-3

Experimental data -...---- 250-3

Use against leal spot diseases ------- 254-5

Use against apple scab --------- 255-7

Use against pear scab --------- 255-7

Use against leaf scald of pear and quince-tree - - . . . 257

Use against various fungi -------- 258-9

Use against insects - - - - - - - - - 259-60

Carbolated, etc., bouillies --------- 260

CHAPTER XV.

Eau Celeste — Copper Phosphate — Copper Borate — Copper Ferrocyanide.

92. Eau Celeste - - -..----. 261-268
Preparation 261

Audoynaud's recipe .---.-.-. 261

Bellot des Minieres' recipe -------- 261

Schweizer's cupro-ammoniacal liquor (cellulose solvent) - - - 261

Ammoniacal solutions of copper carbonate ----- 261

Mohr's recipe .--..----- 262

Properties of eau celeste -.---.-.. 262

Spraying vines, experimental results ..---.. 268

Eau celeste dissolves cellulose -------- 263

Solvent eau celeste mixture for silk ------- 263

Comparative action of blue vitriol and eau celeste on plants and fungi - 264

Use of to combat cryptogamic disease in full evolution - - - - 265

Use against potato and various other fungoid diseases - - - 265-7

Spraying growing wheat with eau celeste -....- 266

Galloway's eau celeste recipes -.--..-- 267

93. Phosphate of Copper, CUHPO4.

Preparation -- 268

Properties - 268

Uses 268

Use against leaf scald of pear-tree ---...- 268

Use on growing grain crops --------- 268

Diminished yield of same --------- 268

94. Borate of Copper, CuB^O^.

Preparation ------- 268

Uses 268

Use against leaf scald of pear -------- 268

Fairchild's bouillie for same -------- 268-9

Increased yield of grain by spraying with borate of copper bouillies - 269

95. Ferhocyanide of Copper.

Preparation ---------.-. 269

Uses 269

Galloway's bouillies, recipes -----..-- 269

Results obtained on growing grain by use of same ----- 269

TABLE OF CONTENTS. Xxi
CHAPTER XVI.

Copper Aceto-Arsenite (Emerald Green, Paris Green), Copper Arsemte
(Scheele's Green) — Copper Silicate — Copper Carbonate — Bouillie Borde-
LAisE Celeste — Verdigris Copper Acetate — Various Bouillies.

PAGE

9(). Aceto-Arsenite of Copper - - - - - - - - - 270

Definition ------.-.... 270

Manufacture ---------.-. 270

Properties (action on plants) ------... 270

Freshly prepared bouillies versus bouillies from commercial green in

powder ------------ 270

Behaviour of arsenic in soil ----..--. 270

The aceto-arsenite free from sodium arsenite innocuous to plants - - 270
Whitehead's harmless doses, recipes for :—

Apple-trees ------..-.. 271

Pear-trees --------.-. 271

Gooseberry bushes ---------- 271

Plum-trees ----.. 271

Currant bushes ---------- 271

Action on insects - - - - - - - - - - - 271

Uses -----... 271

Methods of use - - - - 271

1. In dry state -.-----.-. 271

2. As bouillies ----.---.. 271

Precautions in use ----- 272

Arsenic not absorbed by plant -------- 272

French law interdicts arsenious acid and compounds - . - . 272

Time of spraying ----------- 272

Spraying with arsenites during fertilisation kills bees, etc. - - - 272

Spraying with arsenites suitable for rainy countries . - - - 272
Profit incidental to use of arsenites ------ 272-3

Use against apple scab and potato disease ------ 273

Use against insects, apple weevil, cotton weevil, etc. - - - 273-6

Treatment by powders ---------- 274

Eecipe for same ----------- 274

Treatment with bouillies -----.-.. 274

Use of same inter alia against : —

Colorado beetle, etc. --------- 274

Codlin mo h, etc. - . . . 275

Evesham moth, etc. - - - - - - - - - 276

Aeari ------------ 276

97. Copper .\rsenite, CuoAsoO,.

Preparation (Gaillot's recipe) 276

Properties - . - 276

Use - - 277

98. Copper Silicate, CuSiO...

Preparation ------- 277

Properties 277

Use - ----- 277

99. Carbonate of Copper, CuCO;,.

Preparation, formula for --------- 277

Tests for normal product --------- 277

Properties - - - - - - - 277

Neutral bouillie 277

Various maiiufacturing hints and instructions ----- 278

Uses 278-9

Use to disinfect purchased onions and tubers ------ 279

100. Bouillie Bop-delaish: Celeste.

Preparation --.--.---... 279

Formula - - 279

XXll TABLE OF CONTENTS.

PAGE

Action on fruit trees ---....--- 279

Good qualities of - . . . . 279

101. Basic Acetate of Copper (Verdiorig).

Definition ------- 279

Preparation - - - - 279

Properties (action on plants) --------- 280

Analogies between various copper bouillies ------ 280

Perret's bouillie - 281-4

Use of verdigris against various cryptogamic diseases - . . . 281

Results by spraying growing corn (Galloway) ------ 281

Viala and Pacottet's bouillie (recipe fori -.-..- 281

Galloway's experiments on vines -------- 281

102. Copper Acetate Cu(CoH30o)-H„0.

Preparation ------------ 281

Properties (action on plants) --------- 282

Uses ----------... 282

102a Perret's Bouillie Cupric Saccharate in Part.

Preparation (formula recipe) --------- 282

Properties ----- - 282-3

Action 283

Ratio of sugar to blue vitriol -------- 283

Function of sugar ----------- 283

An ideal bouillie ----------- 283

Possible direct assimilation of saccharate of copper - . - - 283

Galloway's recipe ----------- 284

Bee-keeper's complaints unfounded ------- 284

Use ----- - 284

Deterioration of present product -------- 284

1026. Various Bouillies.

Use of binders ----.-.-.-- 285

Action of binders on organoleptic properties of wine - - - - 285

103. Albuminous Bouillie ---------- 285

104. Lactocupric Bouillie (Crouzel's).

Preparation ----- 285

Formula for - - - - - - 285

105. Bouillie Bobdelaise Modifi^e.

A skim-milk bouillie ---------- 286

Use against poppy rust ---------- 286

Galloway's recipe ----------- 286

i06. Soapy Bouillies.

Soap as a binder in bouillies - - - - - - - - - 286

Oil as a binder in bouillies 286

Copper soaps ...---.-.-. 286

Swingle's recipe - - - - 286

Galloway's recipe ----------- 286

Soapy eau celeste ----------- 286

American recipe for same --------- 286

Comparative adherence of soapy bouillies tested against various other

bouillies -----. 287

Deterioration on storing -..-.--- 287-8

Condeminal's linseed-oil bouillie -------- 288

Addition of petroleum to render bouillie insecticidal as well as anti-

cryptogamic ----------- 288

Stable bouillie, recipe for ..-.-.--- 288

Zacharewitsch's bouillie recipe -------- 288

Results from same ----...-.. 288

Copper soap (in ether, etc.), use of on wounds made by woolly apliis - 288

Insolubility of such coating in water ------- 288

107. Rksinouh (Cupuic Rosinatk) Bouillie.

Porraud's recipe --...-.---- 288

Piecautions in making - - - . ------ 288

Olive oil and tui'ps bouillie - - - - - . - . . 288

TABLE OF CONTENTS. XXlll

CHAPTER XVII.

Mercuric Chloride (Corro.sive Sublimate) — Tin Crystals.

PAGE

108. Mercuric Chloride (corrosive sublimate), HgCla . . . . 289
Preparation ------------ 289'

Properties - - - - . . 289*

Action on plants ----------- 289'

Action as weedkiller --.--..... 289

Stimulating action of intinitesimal dose ------ 28^^

Pickling of seed ----,-----. 289-90

Comparative dose of sublimate, green vitriol, and blue vitriol to kill

spores ---------- . - 290

Action on insects ----------- 291

Uses - - - - 291

Use against lichens -..----.-- 291

Use against potato scab ------- - - 291

Use against beet jaundice --------- 291

Use against vine mildew ------ ... 291.

Use against black rot of grapes -...-..- 291

Use as pickle for seed-corn -.-----.- 291

Disinfection of flower seeds --------- 291

Use against insects - . - . 291

Use against ants -------.--- 291

Use against rodents .....-..-- 291

109. Tin Crystals. SnCL.

Preparation --- -- 293

Properties ----- - 293

Use -----..---.-. 293:

CHAPTER XVIII.

Derivatives or Carbon (Carbon Compounds). Products Derived from the
Fatty Series : Petroleum (Burning Oil) — Petroleum Sprays — Petroleum
Oil Emulsions — Petroleum Soap Emulsions — Petroleum Spirit — Vaseline.
— -\cetylene.

110. Pftroleum -- 295

Occurrence --.-.-...... 295

Commercial products 295

1. Petroleum ether ......... 295

2. Light oils 295

3. Petroleum oil ----- - - . . . 295

4. Heavy petroleum oils -------- 295

5. Crude paraffin wax scale -------- 295

Petroleum oil, burning oil - - ------- 295

Action on plants 295

Action on insects ----------- 295

Use in pure state - - - - - 295

Sprays - 295

Directions (specifications) for spraying -....-- 295

Time for spraying - 296

Action on pear and apple-trees -..----. 296

Use against insects ---.-.--.. 296

To be used against San Jose louse 296-8

Petroleum emulsions 298-301

Preparation and formula; 298-301

Sand emulsion 298

XXIV TABLE OF CONTENTS.

PAGE

Water emulsion i - 298

Salt-water emulsion - - -....-.. 299

Example 299

Ingredients of several emulsions -.-.---. 299

Ingredients of four stable emulsions - - 300

Fish-oil emulsion ----.-----. 300

Milk emulsion 300

Insecticide and metallic salt emulsion .--.-- 300-1

Use of petroleum emulsions against : —

Fungi -----..--.-- 301

Coleoptera ......---.. 301

Hymenoptera .......... 302

Lepidoptera - - 303

Hemiptera ........... 304

Homoptera --.-...-.-. 304

Woolly aphis 305

Coccides ........... 3O6

Dipteia 306

Acari 307

111. Petroleum Spirit.

Preparation - - 307

Action on plants . - - - - 307

Action on insects ---..-.--.- 307

Use - - 307

Petroleum spirit emulsions - - 307

Formula, recipe for - - 307

Use against insects ......... 307-8

112. Vaseline.

Action on plants ---...-..-. 308

Action on insects 3O8

Uses - - - - 308

Ward's recipe for vaseline emulsion - - 808

Use against insects .......... 308

113. Acetylene, C„Ho.

Preparation ------..-.- 308-9

Properties .----...-... 309

Action on plants ---......-. 309

Action on fungi 309

Action on insects --.-...-..- 309

U&es 309

Use against fungoid diseases -....-... 309

Destruction of insects by 310

CHAPTER XIX.

Carron Co.mpounds {continued) — Chloroform — Carbonic Oxide — Methyl Alcohol
— Ethyl Alcohol — Amylic Alcohol — Glycerine (Tri-Hydric Alcohol) —
Etheu — Mercaptan — Formic Aldehyde — Acetic Acid — Oxalic Acid.

114. Chloroform, CHCl., .... ----- 311

Preparation -----.------ 311

Properties ............ 311

Action on plants ..-.-----.. 311

Trials to disinfect seed-corn against formol and ammonia - - - 311

Stimulating action of small doses .----..- 311

Mrs. Ijatham's experiments .-.-..... 311

Johanssen's experiments ......... 311

JJlooming by ........... 311

Action of vapour on spores ......... 312

TABLE OF CONTENTS. XXV

PAGE

Tests, comparative, on seed-corn 312

Action on insects ----------- 312

Uses ------------- 312

114a. Carbonic Oxide, CO.

Preparation ..---------- 312

Properties ------------ 312

Action on red corpuscles ...--.--- 312

Uses ----- 312

Alcohols ------------ 312-15

115. Methyl Alcohol, CH3OH.

Preparation ------------ 313

Properties ------------ 313

Use in admixture ----------- 313

German recipes ----------- 313

Another recipe ----------- 313

116. Ethyl Alcohol, C0H5OH.

Preparation ------------ 313

Properties ------------ 313

Action on plants - - - - 313

Use against insects ---------- 313

Disinfection of flower seed --------- 313

117. Amyl Alcohol, CjHuOH.

Preparation ------------ 314

Properties ------------ 314

Action on plants ----- . . . . - 314

Action on insects ----------- 314

Uses ------ 314

Proprietary insecticides into which amyl alcohol enters with their ingredi-
ents : —
" Nessler's," " Aphidin," " -\ntivermin," " Amylocarbol," Fichet's composi-
tion of " Nessler's " - --------- 314

Composiiion of " Knadolin" --------- 314

Composition of mixed amyl alcohol insecticides ----- 315

Another recipe ----------- 31o

118. Glycerine, CH2OHCHOHCH2OH.

Preparation - - - - . - 315

Use - - - ----- 315

118a. Ether. C.H, . 0 . C.,H5.

Preparation ------------ 315

Properties ----- - 31-5

Action on plants ----------- 315

Uses ------------ 315-6

Stimulating action of small doses on plants similar to chloroform - - 315

Audebei-t's recipe for ethereal insecticide (bordelaise insecticide) - - 316

119. Mercaptax, CoHjSH.

Preparation ------------ 316

Properties ------------ 316

Mouillefert's experiments against phylloxera ------ 316

120. Formic Aldehyi>e (formaline, formol).

Manufacture by Trillat's process - - - 316

Commercial solutions - - - - - - - - - - 316

Formol pastilles ----------- 316

Properties of formic aldehyde -------- 31b

Action on plants - - J^l"

Trials as pickle for seed-corn - 317-19

Tabulation of results ------ 317-19, 320, 322

Action of formol on fungi --------- 318

Action of formol on insects --------- 319

Uses ^p3

Use against potato scab -------- 319-23

Use against grey rot of vine --------- 320

Use against other fungoid diseases ...---- 320

XXVI TABLE OF CONTENTS.

PAGE

Practical disinfection of seed-corn -------- S2d

121. Acetic Acid, CH3COHO.

Preparation ------------ 323

Properties 323

Action on fungi and their spores -------- 323

Uses ------------- 324

Use as pickle for seed-corn --------- 324

Use against gum of stone fruit trees ------- 324

122. Oxalic Acid, COOH . COOH.

Properties ------ - 324

Action on fungi ----------- 324

Uses - - - - - - 324

Uses against canker of pear-tree -------- 324

CHAPTEE XX.

Carbon Compounds [continued) — Oils and Fats — Soaps — Hard SoiP — Soft Soap —
Whale Oil Soap— Fish Oil Soap 323-333

123. Natural Oils and Fats (Glycerides) - - - - - - - 325

P;operties ------------ 325

Colza oil ------------ 325

Poppy oil ----------- - 325

Olive oil ..-.-- 325

Linseed oil ----------- - 325

Whale oil - - - . - . 325

Action on plants - - - - - - - - - -- 325

Action on insects ----------- 325

Uses ----- - - 325-7

Uses against insects --------- 325-7

124. Soaps.

Preparation ----------- 327-8

Solubility of soaps ---------- 327

1'. Hard soaps ---------- 327

Marseilles soap --------- 327

Soap boiling ---------- 327

2. Soft soaps - - - - 328

[a) Whale oil soaps --------- 328

(6) Fish oil soaps 328

(c) Black soap (green soap) .-.--.- 328

Insecticide preparations ..----.-. 328

Composition of (recipe, for) a few insecticides . . . . 328-9

Action of soap on plants --------- 329

Action on insects ----------- 329

Action of Mari^cilles soap .----.--- 329

Action of fish oil soap ---------- 329

Action of whale oil soap --------- 329

Uses 329-33

Use against cryptogamic diseases -------- 329

Use against insects ..--..--- 329-33

Halstfid and Kelsey's recipe - - - - - - - - - 329

Marlatt's recipes ----------- 329

Targioni's recipes . - - - - 330

Ducloux recipe ----------- 331

Ijowe's recipe .-.---.--- 331

Taschenberg's recipe ---------- 331

Delacroix recipe ----------- 331

Muhllxjrg's recipe ----------- 331

Nessler's recipe - 332

TABLE OF CONTENTS. XXVll

CHAPTER XXI.

C.BBON Compounds (continue d)-FROi>vcTS of the Aromatic Sekier : Benzol-
Coal Tau— Wood Tar— Naphthalene.

PAGE

^ „ 334-7

125. Benzene, CgHg - - - ' " 33Y
Preparation ----'''' gg-j

126. Tar - - - - " " " " " ; '. '. ".337

1. Coal tar ----'"

2. Wood tar -----■'■" "
Action of tar on plants ----■""'
Action of tar on insects - - 338"43

337
337
338

Uses

338

" Rubinia," composition of ----"""' _ [_^^^
Tetard's recipe ----""""'_ ggg
Howard's recipe ----"'"'" _ 33g

Balbiani's ointment, recipe -----"'" ggg

Rathay's bouillie ----"""""_ ggg
Use as weedkiller ---"""'' ggg

Use against fungi -----"'' [ _ 339.43

Use on insects ---■''"" 342-3

De Quercio's recipes, - - " _ _ 3^3

Use against rabbits and mice ---;""'_ g^'g

Use against birds -----'''' 3^3^

Use against birds, Howard's recipe -----'

343

127. Naphthalene, Cj^Ha

Preparation -----""'' 344^

Properties - - - - 3^1^^

Balbiani'^ ointment, recipe ----"""' 3^^

Action on plants ----■'""' _ 3^^^

Action on seed germination -----'"'] g^^
Action on insects ----"""'' 344-7

Uses

346

Naphthalenized sawdust ----""'' g^g^

Pradel's naphthalene mixture -----'"] ^^g

Taschenberg's mixture -----""'' 3^^

Mixtures to kill woolly aphis -■"'"""]' 347

Guozdenovic's mixture ----•--"' g^^

A German mixture against phylloxera ----""" ^^^
Guozdenovic's mixture against cochineals ----•"

CHAPTER XXII.

Carbon Compounds (c.«iin«. J)-Terpenes-Oleo Resins-Galipot-Turpentine--
RosiNS-RosiN Soaps-Rosin Emulsions-Metallic Rosinates-Coppeb Rosin
ate — Camphor.

- 348
Terpenes ------- 348-52

128. Turpentine ------■■ 3^^

Action on plants -----■■■■_ 348-9

Action on insects ■ " _ g^g

Recipe for grafting wax - ■ ] 348-9

Uses , ,, ' 349

Mouillefert's experiments against phylloxera ----- ^ ^^^
Use to drive off moles

129. Pine and Spruce Resin [? Rosin]. _ g^g

Uses

Use in soap emulsions

349

XXVni TABLE OF CONTENTS.

PAGE

Use in coatings and bird-limes -...-.-. 349

Use in cupric bouillie as binders -------- 349

Rosin soap emulsions ---------- 349

Numerous recipes - - - - - - - - - - - 350

Action on plants ----------- 350

Action on insects ----------- 350

Uses 350

Bird-limes and coating compositions ....... 351

Numerous recipes for coating compositions ------ 351

Use of coating compositions --------- 351

Use of bird-limes as tar rings --..--.. 351

Clarac's composition against woolly aphis -..-.. 352

Rosin bouillie in which rosin is used as binder . . . . . 352

130. CAMpnoii, Cj„HigO.

Natural occurrence ----...... 352

Sublimation - - 852

Refining - . - - - - - 352

Properties - - - . - - 352

Uses - - - 352

Use against insects - - - - - - - - - . - 352

Use to protect corn-seed, etc., against mice 352

CHAPTER XXIII.

Carbon Compounds (continued) — Nitrobenzene — Carbolic Acid — Picric Acid —
Cresol — " Sapocarbol" — Creosote — " Creolines " — " Lysol " — Potassium
Dinitro-Cresylate— Thymol — /3-Naphthol — Methyl Violet.

131. Nitrobenzene, C„H5N0.3 353-4

Preparation ----- 353

Action on insects ----------- 353

Action on plants ----------- 353

Uses ----.-----.- 353-4

Papasogli's recipe ----------- 353

Use against insects --------- 353-4

Knadolin ---.---...-- 354
Composition of same ---------- 354

132. Carbolic Acid, CgHgOH.

Preparation - - - - - - - - - - - - 355

Properties ----.--.---. 355

Action on plants ----------- 355

Action on fungi .---...--.. 355
Action on insects ----------- 355

Use as weedkiller -------- . . - 355

Use against bacterian, etc., diseases ------ 355-6

Use as steep for beet seed -.-.--.- 355-(5

Experiments in disinfecting beet seed ---.--- 35(5
Method of disinfection ---------- 356

Use against insects ......... 356-B

133. Tuinitrophenol or Picnac Acid.

Preparation ------------ 358

Properties ............ 358

Use as picl<le for seed-corn --....--- 358

Action on insects ---.------- 358

/OH

134. Crksoi, or Crehylol, CuH^'.

\CH.,
Preparation ---------- . - 359

Properties ............ 359

TABLE OF CONTENTS. XXIX

PAGE

Commercial preparations containing cresylol ------ 359

Sapocarbols ----- 359

Lysols - - - - 359

Creolines 359

Solveol -------- 359

Amylocarbol --..---.... 359

Thymocresol -..-.- 359

135. " Sapocarbol."

Preparation ------------ 359

Properties ------------ 359

Composition ..---..... 359-60

Action on plants ------ 360

Action on plant lice --.--..--. 36O

136. "Creolines."

Artmann's creoline ----.--... 35^

Properties -------..... 361

Action on plants --------... 36I

Action on plant lice -----...-. 3g2.

Uses 361-2

Disinfection of seed potatoes --------- 361

Use against insects - - - -.-.... 352

Recipes for mixtures which gave good results against cochylis - - 362

137. Creosote (wood tar).

Preparation ------------ 362

Properties 362

Uses - - - . 362-3

Use against insects -.-.--..-. 363

American recipe for gipsy moth -------- 363

Mouillefert's experiments on vines -..--.. 363

138. " Lysols."

Preparation -.-. 363

Properties ---------... 364

Action on plants ----------- 364

Action of solutions of various strengths on organs of different plants - 364

Action on fungi ------.--.. 354

Action on plant lice -----..-.. 365

Use against fungi ---------- 365-6

Coating fruit trees in winter against insects 366-7

Use against insects ---.--.-. 366-7

139. Potassium Dinitro-Cresylate.

Properties 367

Action on plants - - - - - - 368

Action on insects ----------- 368

Action on mice and rats -----.-.. 368

140. Thymol.

Preparation ---- 368

Properties 368

Use - - - - 368-9

141. /3-Naphthol, CjoH-OH.

Preparation -- 369

Properties 369

Action on plants - - - - - - - - - - - 369

Action on fungi ---.-----.. 359

Recipes for naphthol mixtures -----... 369

Naphtholate of soda - . . 369

Naphtholate of lime - . 369

Naphtholate of copper - - - - 369

Naphtholate of iron - - . - 369

Use against fungi 369-70

142. Methyl Violet or Pyoctanine.

Preparation ------------ 370

Properties 370

Use 370

XXX TABLE OF CONTENTS.

CHAPTER XXIV.

Carbon Compounds (coiitimied) — Tobacco (Nicotine Tobacco Jdice) — Quassia —
Hellebore — Pybethra — Delphinium (Larkspur) — Strychnine — Nux Vomica
— Walnut Leaves — Glue— Cutch — Aloes.

PAGK

143. Tobacco 371-5

Recipes for tobacco insecticides (7) ------ 371-2

Properties ------------ 372

Action on plants ----------- 372

Action on insects ----------- 372

Uses - 372-5

Fumigation ------------ 372

Use in open air ----- 372-3

Spraying with tobacco juice --------- 373

Use against insects --------- 372-5

Nessler's tobacco insecticide - . . 371-4

Sajo's recipe ---------- 374-5

Sajo and Czerhati's recipe --------- 374

Ahliech's recipe - . - - - 374

Mohr's recipe -.-.-----.- 375

Guozdenovic's recipe ---------- 375

Noel's method ..--.------ 375

Sirodot's method - - - 375

144. Quassia Amara

Insecticides with quassia basis - - - - - - - 375-6

Numerous recipes ---------- 375-6

Properties ------------ 376

Action on plants ----------- 376

Klein's solution ----------- 376

Action on insects ----- ----- - - 376

Uses - - - - - 376-7

Mouillefert's experiments on vines - - - - - - - 377

A German quassia mixture against phylloxera ----- 377

Recipe against Phytoptus Ribis -------- 377

145. Hellebore Root.

Preparation of liquid insecticides - - - 377

Several recipes ----------- 377

Uses - - - 377

Against insects - - - - - - - - - - - 377

Against sparrows ----------- 377

Against rodents ----------- 377

146. Pyrethra.

Preparation of pyrethra powder -------- 378

Preparation of pyrethra extracts -------- 378

Soap extract (recipe) ---------- 378

Alcoholic extract (recipe) --------- 378

Alcoholic and ammoniacal extract (recipes) ------ 378

Composition of pyrethra insecticides (recipe) ------ 378

Cupric insecticide bouillie (recipe) ------- 379

Alcoholic and carbon disulphide extract (recipe) ----- 379

Pyrethra petroleum emulsion -------- 379

Properties of pyrethra ---------- 379

Action on plants ---.-.--.-- 379

Action on insects ----------- 379

Uses 379-81

Use against insects --------- 379-81

14'( Strychnine.

Source ------------- 381

Uses ------------- 381

Use against insects -.--.-.-.- 381

TABLE OF CONTENTS. XXXI

PACE

Use against sparrows ----- 381

Use against rodents - - " ^^'^

148. Delphinium (larkspur).

Preparation, properties, and use 382

149. Glue.

Use ------------- 382

Use against insects . - 382

150. CUTCH.

Use against oidium '^^^

151. Rose L.\urel.

Uses Ill

Use of infusion against insects 382

152. Aloes.

Source

382

Properties ^^

Use in human medicine - - - 382

Use as addition to bouillie bordelaise 382

Glossary - - - - 383-406

Index - - . • - ■ - 407-431

LIST OF TABLES.

A. Tables Showing Effect of Watek, Hot and Cold, and of Hydrogen

Peroxide.

paqe

Table I. — Showing the effect of the systematic immersion of vineyards on the

volume of wine produced --------- 26

Table II. — Showing the daily loss of water by absorption by the soil during

immersion ------------ 27

Table III. — Showing the increase (1) in the area of submersion, (2) in the

inseeticidal treatment of French vineyards, 1880-1890 - - - - 30

Table IV. — Showing the temperature at which the spores of different varieties

of Ustilago are killed ---------- 32

Table V. — Showing the effect of steeping seed-barley in hot water on the

germinative capacity ---------- 34

Table VI. — Result of steeping seed-wheat in hot water for different lengths of

time -------- 34

Table VII. — Effect of steeping seed-oats on germinative capacity - - - 85

Table VIII. — Effect of steeping seed-rye in hot water on germinative capa-
city - 35

Table IX. — Inactivity of hydrogen peroxide on Puccini a uredospores - - 40

B. Tables Showing Use and Effect of Sulphur and of Sulphuric Acid,

Chlorine, Hydrochloric Acid, and Arsenious Acid.

Table X. — Proportions of sulphur and lime used in mixtures against anthrac-

nose at different stages of treatment ....... 52

Table XI. — Effect of steeping seed-wheat for different lengths of time in solu-
tions of dilute sulphuric acid, oil of vitriol, of various strengths on its
germination capacity per cent ---..-.. 84

Table XII. — Showing the action of dilute sulphuric acid of 0-5 per cent on the

spores of oats and wheat -.--.--.- 85

Table XIII.— Showing the strength of dilute sulphuric acid required to kill
the old and young spores of Ustilago of barley, oats, and wheat respec-
tively, and the circumambient temperature ------ 85

Table XIV. — Showing the action of different doses of sulfarine (Kieserite) con-
taining 15 per cent of sulphuric acid on the potato disease - - - 87

Table XV. — Showing the effect on the chlorine content of forest timber in

proximity to a hydrochloric acid works ------- 89

Table XVI. — Showing sensitiveness of leaves of various fruit trees to solutions

of arsenious acid of various strengths -...--- 94

C. Tables Showing the effect of Nitrate of Soda, Muriate or Potash,

Potassium Cyanide, and Magnesium Chloride.

Table XVII. — Showing the effect of a 30 per cent solution A and of a 15 per

cent solution B of nitrate of soda on different plants . . - - 1O8
Table XVIII. ^ — Showing the action of a 30 per cent solution and a 15 per cent

solution of potassium chloride (muriate of potash) on farm crops - - 118
Table XIX. — Showing the amount of potassium cyanide, water, and sulphuric

acid to use in cyaniding trees of different height and diameter - - 133
Table XX. — Showing the effect of 30 per cent and 15 per cent solutions of

magnesium chloride on plants .--..... KJl

xxxii

LIST OF TABLES. XXXUl

D. Tables Relating to Green Vitriol and Chrome Salts.

PAGE

203

Table XXI. — Showing the number of pounds of green vitriol which wheat,

rye, barley, and oats can bear per 100 lb. of soil 174

Table XXII. — Showing the comparative strength of solutions of blue and
green vitriol respectively required to kill spores of Phytophthora, Perono-
spora, Ustilago, and Puccinia 175

Table XXIII.— Showing the results of the experiments of De Dombasle on
the disinfection by green vitriol of seed-corn artificially infected for the
purpose ------ - lo^

Table XXIV. — Showing the toxic dose of chrome salts in a nutritive solution 189

E. Tables Relating to Blue Vitriol and to Copper Salts.

Table XXV. — Showing the distribution of insecticidal and anti-cryptogamic

copper between wine, marc, lees, etc.

Table XXVI. — Showing the effect of solutions of blue vitriol of various

strengths on spores of Ptiytophthora, Peronospora, Ustilago, Puccinia,

and Cliviceps " ^10

Table XXVII. — Showing the effect of steeping seei-corn in solutions of blue

vitriol of different strengths for different periods of time - - - 217

Table XXVIII.— Showing the effect on height of plant of steeping seed in

solutions of blue vitriol of various strengths - 217

Table XXIX. — Showing effect on germination of steeping injurtd seed-corn in

water and in solutions of blue vitriol - - 218

Table XXX. — Showing effect on germination of seed-barley of steeping in

solutions of blue vitriol of various strengths 221

Table XXXI. — Showing delay in germination by Kuhn's treatment - - 221
Table XXXII.— Showing effect of blue vitriol steep on crop of barley - - 221
Table XXXIII. —Showing sensitiveness of seed-oats to blue vitriol steep - 222
Table XXXIV. — Showing delay in germination by blue vitriol steep of seed-
oats (Kuhn's method) 222

Table XXXV.— Effect of blue vitriol treatment of seed-oats on the crop - - 222
Table XXXVI. — Showing reduction in germinative capacity by delay in

sowing after steeping seed-corn in blue vitriol ----- 223

F. Tables Relating to Bodillie Bordelaise.

Table XXXVII.— Effect of 2 per cent bouillie bordelaise in preventing potato

scab - 237

Table XXXVIII.— Showing effect of bouillie bordelaise of various strengths
on weight and starch content of potato crop and on the percentage of
diseased potatoes ----------- -39

Table XXXIX.— Showing beneficial effect of repeated spraying with copper

bouillies on potatoes .-.------- 239

Table XL. — Showing effect of bouillie bordelaise on potato disease - - 239

Table XLI.— Showing effect of first spraying on the weight of the crop of

Magnum Bonum pot;itoes --------- 240

Table XLII. — Showing number, weight, and size of large and small potatoes

before the appearance of the disease on treated and untreated plots - 241

Table XLIII.— Showing number, weight, and size of large and small potatoes

after the appearance of the disease 241

Table XLIV.— Showing the effect of various copper preparations on the bulk

of the potato crop and the number of diseased potatoes - - - 241

Table XLV. — Showing composition of moistenable sulphur- - - - - 249

Table XLVI. — Showing the composition, volume per acre, time of treatment,
order of sequence of bouillies bordelaises used in the prevention of black .
rot of the vine ----------- 251

Table XLVIL— Showing order, time of spraying, and strength and composi-
tion of bouillie bordelaise in treatment of black rot of vine - - - 251

Table XLVIII.— Showing results of repeated spraying of vines with solutions

of blue vitriol of various strengths 253

C

XXXIV LIST OF TABLES.

Table XLIX. — Showing the effect of spraying with bonillie borclelaise on the

percentage of diseased pears --------- 256

Table L. — Showing the effect of repeated spraying with bonillie bordelaise on

the percentage of diseased pear-tree leaves ------ 257

G. TABLES Relating to Eau Celeste, Cupro- Albuminous Bouillies,
AND TO Corrosive Sublimate.

Table LI. — Showing the effect of spraying vines with eau celeste on the
density of the wort, the weight of the wort per kilogramme of grapes, the
sugar content per litre of the wort, and the weight of the grapes - - 263
Table LII. — Composition of Galloway's eau celeste ----- 267
Table LIIL^Showiug the percentage of sound grapes on untreated vines and

on vines treated by eau celeste made by two different formulae - - 267

Table LIV. — Showing the effect of disinfecting haricot bean seed with eau

celeste - . - 267

Table LV. — Showing the effect of spraying bramble bushes with eau celeste - 268
Table LVI. — Composition of cupro-albuminous bouillies - - - - 286

Table LVIL — Showing the dose of green and blue vitriol and corrosive sub-
limate required to prevent the germination of the spores of different
parasitic fungi -------...- 290

Table LVIII. — Showing the respective doses of corrosive sublimate re-
quired to prevent the germination of spores of the various species of
Ustilago - - - ■ 290

H. Tables Relating to Petroleum Emulsions, Nessler's Insecticides, etc.

Table LIX. — Showing ingredients of several petroleum emulsions - - 299

Table LX. — Ingredients of four stable petroleum emulsions - - - . 300

Table LXI. — Showing the disinfectant capacity of anti-cryptogamic vapours - 312

Table LXII. — Showing the composition of Nessler's insecticides - - - 314

I. Tables Relating to Use of Formol (Formaline).

Table LXIII. — Showing effect of steeping seed-oats on formol solution on

germination ------------ 315

Table LXIV. — Showing effect of steeping seed-oats in formol solutions on

germination ---.-------. 317

Table LXV. — Showing effect of twenty minutes' steeping in formol solutions of
various strengths on the germinative capacity of seed-corn. Water = 94-5
per cent ------- 317

Table LXVI. — Showing effect of duration of steep in formol solutions on

germinative faculty of seed-corn ------.. 313

Table LXVII. — Showing effect on oat crop of steeping the seed-oats in solu-
tions of formol of different strength and for ten minutes up to one hour - 319

Table LXVIII. — Showing the results of growing oats from undisinfected
seed and from seed disinfected by 2 per cent bouillie bordelaise, and from
seed disinfected by 0-2 per cent and 0 3 per cent solutions of formaline - 321

Table LXIX. — Showing the effect of solutions of formaline corrosive sublim-
ate, oil of vitriol, and blue vitriol on the germinative capacity of millet
seed and the spores of Ustilago cramori ------- 322

Table LXX. — Showing the effect of certain disinfecting fluids on the crop pro-
duced from the rusty seed-corn which floats on the fluid - - - 322

Table LXXI. — Showing the action of fonnol and lime and mixtures thereof

on onion rust .--.-. 323

J. Tables Relating to Use of Preparations made from Coal-Tar Products.

Table LXXII. — Showing action of naphthalene on germinative capacity of

cotton seed ---.-.-..- . 344

Table LXXIII. — Showing the comparative amount of active ingredients in

various brands of " sapocarbols " and "lyeols" ----- ggQ

LIST OF TABLES. XXXV

PAGE

Table LXXIV. — Action of " sapocarbol " on plants . . . . . ggo

Table LXXV. — Action of "sapocarbol" on plant lice ----- 360

Table LXXVI. — -Showing action of Artniann's " cieolin " on plants - - 301

Table LXXVII. — Action of Artmann's " creolin " on plant lice - - - 361
Table LXXVIII. — Showing compasition of "creolin" mixtures which give

good results against plant lice -------- 362

Tablk LXXIX. — Showing the action of " lysol " solutions of various strengths

on the organs of different plants -------- 364

Table LXXX. — Showing the action of " lysol" solutions of various strengths

on plant lice ------------ 365

K. Tables Eelating to Use of Tobacco, Quassia, and Psrethra
Preparations.

Table LXXXI. — Action of tobacco juice on crioceris of cereals - - - 373
Table LXXXII. — Showing the action of Klein's quassia solution on the

organs of various plants --.--..-. 376

Table LXXXIII. — Showing the composition of pyrethra insecticides - - 378

INTEODUCTION.

Relative and Absolute Diseases. — Plants, like man and animals,
in virtue of their living cellular constitution, are liable to disturb-
ances of their physiological equilibrium, that is, to diseases. The
diseases of plants are quite as well defined as those of animals, and a
certain analogy exists between them, so also with the inducing causes.
We again find amongst these causes the same physical, chemical, or para-
sitic elements. These causes generally co-operate to produce disease ;
but one cause is always preponderant and serves as a basis for clas-
sification. Plant diseases are divided into (a) rdatite and {b) absolute
diseases. Eelative diseases are a return to the natural wild state of
the plants artificially selected and profoundly modified by man, and so
it is that Brussels sprouts, turnip cabbage, and the dititerent species of
cauliflower are dei'ived from a species of cabbage to which a disease
Parenchymatosis has been imparled artificially by over-nitrogenous
feeding systematically pursued for several generations. The tend-
ency of these plants to form large fleshy buttons, in the form of a
cabbage-head, or excrescence of the stem, is not at all inherent in the
species, and it is not unusual in dry seasons to observe a leturn of
these plants to the primitive condition. This degeneration is regarded
as a relative disease. It is the same with fruit trees ; we skilfully
maintain by pruning the morbid condition w^hich forces them to pro-
duce an exaggerated amount of fruit so as to accomplish in this way
the end which we assigned to them. Their return to the natural state is.
regarded as a degeneration or a relative disease. Absolute diseases,
result, on the other hand, from more or less profound alteration,^
general or local, of the organs of the plant ; from a more or less ex-
tensive and complete alteration of the cellular tissue. It is to absolute-
diseases alone that the etiological observations which are about to be:
examined apply.

Etiology. — Etiology is that part of pathology which is con-
cerned with the research of the origin of diseases, and examines the
causes which induce them. The latter are divided into effective
causes (those which actually cause the disease) and adjuvant (helping,
predisposing) causes (those which place the plant organism in such a
condition that the effective causes can act). In practice, these causes
are confused and linked together in such a way that an adjuvant cause
in a given disease may become an effective cause in another disease.
It has been seen that the etiological factors of disease may be divided
into (1) physical, (2) chemical, and (3) parasitic.

(i) Physical Causes. — These depend on climate and season.
Heat, cold, drought, and humidity, more or less sun-light, are factors

1

2 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

which greatly influence plant growth. They cause deadly plant
diseases when all favourable conditions do not work together. Here,
as in the animal kingdom, the great law of selection intervenes.
Only plants able to live in the existing climatic conditions will
subsist, the others suffer, fall ill, and disappear. There are few
remedies for climatic causes.

(2) Chemical Causes. — These relate, especially, to the chemical
composition of the soil, from which the plant draws the elements
required for life and growth. These may exist too abundantly, or not
in sufficient amount. Ee terms those diseases due to an excessive
amount of nutritive elements sthenic diseases, and those due to an in-
sufficient amount asthenic diseases. These physical and chemical
causes favour the hatching of parasitic diseases. Plants weakened by
these causes can exert little or no cellular resistance to being overrun
by parasites, which find in them a medium favourable to their growth
and development, for however unfavourable these conditions may be
to the development of the plant, they are, precisely, those which
favour the evolution and multiplication of parasites.

(3) Parasitic Causes. — The evolution of all parasites, animal or
vegetable, should be well known, as they are neither injurious nor
destructive to the same extent in different phases of that evolution.
Each parasite has a very characteristic evolution, more or less long,
always the same for the same species. (1) Anmial Parasites. — These
belong to the most diverse classes, but insects especially occasion the
most frequent and perceptible damage. The insect originates in the
«gg. The insect which it contains passes through very different con-
ditions, until after a greater or less length of time it becomes perfect,
that is, capable of laying eggs to ensure its reproduction. The
sequence of these intermediate conditions is called metamorphosis,
and the different forms, larvae, caterpillars, grubs, chrysales, etc. It is
especially in the larva form that the insect is most injurious, because
it sometimes remains several years in that condition. That form
represents in every instance the longest period in the life of the insect.
A sound knowledge of these metamorphoses, of the periods at which
they take place, and the spots where they occur will render the
struggle against insects at the moment of their evolution — when they
are the most sensitive to insecticides and when they cannot withstand
their energetic action — comparatively easy. (2) Vegetable Parasites.
— These include fungi and certain phanerogams. Fungi have
also an evolution, differing greatly with the species, and often ver)'
complex. Their method of reproduction, the time and place where the
spores are produced as well as the plants on which these spores can
germinate, should be known. The elements of reproduction of fungi
are spores (name given to seeds of fungi). These spores develop
when climatic conditions permitting their evolution are realized.
The mycelium (this is the name given to the new-born parasite) can then
expand, either in the interior or on the exterior of the plant. In both
oases it lives at the expense of the cellular tissue, and in so doing pro-
duces characteristic diseases. Organs of reproduction are formed on
the mycelium, from which spores that spread the disease are de-

INTRODUCTION. 3

tached. The spores produced differ wi h the season and locality of the
plant. They are differentiated into (1 summer spores, very delicate,
which generally produce a mycelium forthwith, and (2) winter spores,
very hardy, which do not develop until after a winter passed as such.
No general rule can be given as to the evolution of fungi. It differs
as much from one species to another as in that of insects. Species
exist of very complex forms, the evolution of which obliges them to
pass each cycle on very different species of plants. The suppression
of one of these plants in the district may lead to an instantaneous and
complete stoppage of the disease. These fungi are not all equally injuri-
ous. The following classification, based on their action on plants, has
been adopted : (a) Absolute parasites, (b) Wound or iveakness jJarasites,
and (c) Facultative parasites. {a) The first, the most dangerous, are
capable of attacking healthy plants, (b) The second can only attack
the plant if its physiological condition is abnormal, i.e. attacked by
disease, if its vital energy be diminished by climatic conditions ; or if
hail, or frost, grub, or other cause, has made an opening in the epi-
dermis, enabling them to penetrate into the interior, (c) The third are
the fungi formerly termed saprophytic fungi as opposed to parasitic
fungi. Whilst the latter draw their nutriment from the living cell, the
former live on inanimate organic matter. It has been ascertained,
nevertheless, from the profound study of cryptogamic diseases that
saprophytic fungi may, in most instances, become dangerous parasites
il, through special circumstances, the plant cell may happen to con-
tain elements sought after by one of these fungi. Thus the peuicillium
glaucum, the well-known green mould, which usually grows on an in-
animate medium, is attracted during the ripening of fruit by the sugar
contained in the latter, and penetrating therein causes them to rot.
(3) Microbe Parasites. — In the case of a microbe parasite it is especially
necessary to know what factors induce its development, which is closely
connected with the composition of the cellular substance, the tem-
perature, and the moisture. Plants, however, suffer less from these
than animals, because the reactions of vegetable plasma are acid,
which are less favourable to their evolution than an alkaline
medium. However, 'the daily discovery of parasitic microbes helps
to throw light on some of the morbid phenomena of plants, and
microbes appear to play a most important role in plant pathology.

The antagonism between animate beings, as much animal as vege-
table, which live in the same medium does not give rise solely to very
weak, morbid conditions, but also to relations between beings of very
different species, which are advantageous to the two antagonists.
These associations are termed symbioses. De Bary, generalizing the
term symbiosis, distinguished (1) Mutualistic syrnbiosis or advan-
tageous co-operation of the two associates, and (2) Antagonistic
symbiosis, where the one lives at the expense of the other. Vuillemin,
on the other hand, calls the first association symbiosis and the second
antibiosis.

I. Mutualistic Symbiosis. — Many cases of evident symbiosis occur
between phanerogams and cryptogams, between cryptogams and
microbes, and between phanerogams and microbes. Amongst these sym-

4 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

biotic associations the lichens must be regarded as the most typical and
the most perfect example. It is the most complete association known,
where the elements, fungus, and alga are so closely associated that
henceforth it is impossible for them to live apart. The most interesting
cases are those of evident symbiosis between certain fungi and trees
such as Fagiis (beech), Corylus (hazel), Castayiea (chestnut), and
several species of ConifercB. In this symbiosis, known as Mycorhiza,
the mycelmm of the fungus invades the roots of the tree, and, whilst
borrowing the necessary elements of life from the tissues of the plant,
cedes to it the nutritive elements favourable to its growth. Other
symbioses of great importance to agriculture exist between certain
cultivated plants and certain microbes. We have, on the one
hand, the Bacteriorhiza of Hiltner and Stromer, in which bacteria,
whilst drawing their nutriment from the cells of the root epidermis
of Beta (beet) and Pis^im (pea), without injuring the latter pre-
vent injurious fungi, such as Phoma and others, from invading and
destroying these plants. Again, microbes and Leguminosa, are as-
sociated together : Bhizobmm leguminosanmi (Frank) and Bacillus
radicola (Beijerinck). These bacteria live on the excrescences, the
characteristic nodosities which they produce on the ro'ots of the
LeguminoscB. If they draw the necessary elements of life from the
cellular tissue of the root, they as a matter of compensation cede to
the nursing plant nitrogen of the air in an assimilable form. These
symbioses are favourable to the development of the plant, and the
rupture of this association necessarily creates a less prosperous state,
more akin to a grave pathological condition ; the more complete the
symbiosis the more the health of the plant depends on the nutritive
elements with which these associates are capable of supplying it. In
the disinfection of the soil by chemical agents it sometimes happens
that by destroying noxious parasites, the mutualistic parasites are des-
troyed at the same time, and that in curing one disease another is
created. Pure cultures of these useful bacteria, or of the mycelium of
mutualistic fungi, must, therefore, be spread on the fields some time
after disinfection. Pure cultures of these bacteria are on the market,
under the name of " Nitragine," etc. The very contradictory results
obtained on the large scale by the use of pure bacteria arise from the
fact that these should be applied, not upon a?iy soil, but on a soil dis-
infected by carbon disulphide. The soil is like a wort, and there is a
great analogy between selected leavens (yeasts) and soil bacteria. The
selected leavens cannot yield a result except on wort previously freed
— by sterilization, by means of heat — from any other leaven which
would hinder their development. In the same way, the soil which it
is desired to sow with mutualistic bacteria should be freed, by previous
disinfection, from the elements which can, by their presence, oppose
the normal evolution of these useful bacteria. Each plant possesses
its own bacteria, and in each particular case requires the aid of a pure,
selected, and well-defined culture of microbes.

2. Antagonistic Symbiosis. — The most common result of the an-
tagonism between animated beings is the parasitic disease — general or
local — to which the plant, badly equipped, or in bad condition to resist

INTEODUCTION. 5

the attack of its enemies, succumbs. The number of plant parasites is
immense, and they are found in all classes of animated beings (phane-
rogams, cryptogams, bacteria) as well as animals (worms, insects, acari)
living at the expense of the plant. They all become more dangerous, tfhe
one more than the other, in so far as they find the medium favourable
to their development and extraordinary multiplication — a medium of
constant and invariable composition, and climatic conditions lying be-
tween narrow limits, to which are intimately linked the growth and
reproduction of each organism. Between enemies the struggle is con-
stant. The reaction of the plant against the parasites which threaten
it, its cellular activity, which opposes to them its layers of bark which
creates deposits of tannin, of acids in the cells, layers of wax on the
epidermis, prevent it from succumbing. There is no disease until the
reactive forces of the plant become powerless to prevent the develop-
ment of parasites, until the disposition of the subject, and special and
exceptional conditions, facilitate their evolution, increasing their viru-
lence and their number. There is, however, disease when ihe parasitic
antagonists imported from a foreign country (as was the case with
certain insects imported from America, and as is seen in America as
regards insects of European origin) are deprived of their natural
parasites capable of hindering their abnormal multiplication. Great
invasions of parasites must be regarded, in fact, as accidents, for nature
has attached to each ravager one or more parasites which live at its
expense,- just as it itself lives at the expense of the plant. These
parasites obey the same laws as the ravagers, multiply with the same
rapidity as the latter, and by diminishing their numter is the check
which nature opposes to the abnormal multiplication of the species.
Moreover, sudden changes of temperature at the time of the casting of
the skin of the larvae of the insects — then ver}^ delicate — frosts, heavy
rain, free electricity, appear to be some of the causes which hinder the
development of too great a number of parasites. In nature these
causes prevent epidemics, which would be very rare if man did not,
by his methods of culture, create specially favourable conditions for the
evolution and multiplication of parasites. Formerly, this state of affairs
was remedied by the bare fallow ; to-day, rotations are preferred ; to-
morrow, the annual disinfection of the soil by means of carbon disul-
phide, that of the underground and aerial (above ground) part of plants
by insecticides and anticryptogams will definitely abolish a condition
which necessarily results from our methods of cropping. We must re-
place by new processes the action of stable equilibrium which is mani-
fested in nature and which we have suppressed. It wall be seen, however,
that the complete destruction of parasites is not indispensable, but even
injurious, and that disinfection should only re-establish equilibrium,
a modus vivendi between the plant and its parasites. It is necessary,
in fact, to avoid diminishing in the plant the reactive force of the cells,
so thac these may always be armed -and active, and able at any moment
to sustain the struggle against parasites. This equilibrating disinfection
is only realized, up to now, in the treatment of the vine against
Phylloxera and cryptogamic parasites by the annual treatment (a) of
the soil by weak applications of carbon disulphide, of dissolved sulpho-

6 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

carbonate, and (b) the aerial or above-ground parts of plants by
sulphuring, multiple spraying with weak cupric bouillies, washing of
the stock with ferrous sulphate (green vitriol), and by scalding or
hot water treatment. The number of plant diseases daily increases,
as now we do not solely cultivate native plants, but more and more
foreign species imported into the country. The deportation of the
latter places them in new conditions against which nature has not
ai^med them ; and in the country of their exile they are defenceless
against parasites. But these plants import parasites which find a
favourable medium for their evolution in the plants of our country,
against which the latter are not armed. Thus it is that very severe
diseases have appeared in our crops, and that America has been
dowered with parasites, harmless with us, but formidable enemies in
that new country.

Therapeutics. — Therapeutics is that part of medicine which treats
of curative agents and studies the manner of using them in the treat-
ment of disease. Vegetable therapeutics is based on physiological
data on the knowledge of the physico-chemical properties of curative
agents, on their action (1) on the plants to be treated, (2) on the
factors which cause the disease. It will therefore be necessary to
indicate in the case of each chemical product used in the treatment
of plant diseases (1) The process of manufacture of the chemical
product. (2) Its physico-chemical properties, a knowledge of which
facilitates the preparation of therapeutic specialities and makes known
their mode of action. (3) Its use in human medicine. (4) Its action
on the plants treated. (5) Its action on the parasites to be overcome,
or on the factors injurious to plants. Curative treatment is surgical
when the effective causes are suppressed without the aid of chemical
products, and chemical when recourse is had to the aid of chemical
products. The use of the one does not exclude the use of the other,
and the two utilized simultaneously may produce a better effect.

Surgical Treatment. — Surgery, or operatory medicine, is the
part of medicine which comprises the intervention of the naked hand
or the hand armed xoith i^istruments. The intervention of the hand
armed with instruments has given rise to vegetable surgery, the inter-
vention of the naked hand to the methods of destruction of parasites —
picking, collecting, trapping, baiting.

Vegetable Surgery. — Vegetable surgery has many analogies with
animal surgery. An organ deeply attacked or capable of being regarded
as a seat of infection should be removed in either case. That is so
much the more easy in the case of a plant, as the latter is a being
whose growth, by budding, is indefinite, and that the organs removed
are replaced by equivalent organs in a comparatively short time.
The researches of Eeaumur, Ratzeburg, Robert, Count Jaubert, and
Knight have shown how vitality may be restored to a sickly tree.
The best known process, called " phloioplasty," consists in removing
in a partial or general way the old bark from the trunk and large
branches of a diseased tree as far as the liber. The dressing of the
wounds, which ought to be kept as clean as those of man, is done
thus : If the disease be so deep seated as to necessitate exposing the

INTRODUCTION. (

wood, a protective coating, after cleaning, is spread on the surface of
the wood, which preserves the wound from contact with the air, but
if there be a hving piece of bark (parenchyma, cortical fibres, or liber),
whether in the heart of the wood or on its edges, it must be respected
and protected by some folds of the suberose layer. In this latter case,
the application of a coat of tar would be fatal, especially if used hot.
The artificial wound method is practised to restore health to a tree
whose bark is invaded by scolytus. Longitudinal incisions are made
on the parts attacked, penetrating the cortical layers only as far as
the liber. In serious cases, a narrow band is removed from the
suberose layers. This superficial incision induces a flow of sap, leads
to the formation of new tissue, and stops the transversal progress of
the larvae of the scolytus. If the tree has been invaded in all parts
by scolytes, the great part or even the whole of the circumference of
the tree is decorticated but so as not 'to wound living tissue. "When
the strips are removed, hems are formed ; when the tree is completely
decorticated, a network of cortical fibres is seen to form on the sur-
face, the diameter of the tree grows, and a new bark is formed.
Surgical interventions of this kind, although rarely employed, may
be useful when chemical treatment has no effect.

Methods of Destroying Parasites by the Naked Hand. — When
a parasite is of appreciable size, and especially when it forms visible
and accessible colonies, its suppression by catching gives immediate
results. On a large scale the parasites may be induced to localize
themselves in spots where their destruction, is easy. According to
circumstances the methods used are (1) Picking or catching, (2) Traps
or baits.

Picking and Catching. — Coleopterous insects (cockchafers), gi-ubs
of butterflies, especially when they live in colonies, the agglomeration
of eggs of certain Bombyx (Ocneria) are picked. This picking is gener-
ally done by hand. However, when it is desired to pick small insects
rapidly, tinned iron funnels with a wide mouth are used, above
which the infected organs of the plants are shaken. The neck of
the funnel is connected with a cloth sack into which the parasites
fall (altise of vine). The gathering of insects on farm land is also
accomplished by aid of poultry. For this purpose there are portable
hen-houses, which are drawn iiato the middle of the fields. The
poultry wandering about at will soon free the plants and the soil from
all their parasitic insects. It is a very cheap, useful and ready
method.^

Traps and Baits. — To facilitate the collection of insects and their
larvae artificial shelters fixed on the plants have been tried. The
trunks of trees in autumn have been girdled half-way up with un-
dulating cardboard bands of about four inches wide or with bands of
straw. All the insects which hibernate as perfect insects take refuge
there. All that has to he done is to remove and burn the refuges.
This process is of frequent use in Germany to destroy the vermin of
fruit trees.

' Translator's Note. — Neither British farmers nor British gardeneis take kindly
to poultry, and both would regard the cure as worse than the disease.

8 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Traps fulfil the same purpose as shelters, they draw the insects to
a certain point and render them more accessible to destruction. When
a polyphagous (omnivorous) insect has a marked predilection for a
plant, trap-plants are sown between the lines of the crop. The insects
prefer to seek the trap-plant, on which it is easy to collect them or
destroy them by energetic chemical means, destroying both the insects
and the trap-plant at the same time. The larvae which ravage the
plants in the soil may be destroyed by analogous methods. Fleshy
roots or tubers are buried in the soil between the rows of the
cultivated plant which are removed when the parasites have chosen
a domicile there. Nematodes and grey worms, which are polyphagous
but have a marked predilection for certain tubers, are destroyed in
this way.^ Lantern-traps are used to destroy winged nocturnal para-
sites, butterflies, and coleoptera. They form luminous fires which
attract the moths at night. Acetylene lamps fitted with a reflector
and surrounded with a plate coated with birdlime retains the nocturnal
visitors. This process is used in viticulture in which it helps to
lessen the Pyralis and the Cochylis. Therapeutical surgery is there-
fore chiefly used to combat animal parasites.

Chemical Treatment. — Cryptogamic diseases require chemical
treatment, for it is a case of overcoming organisms so infinitely little
that the eye can often only see them with difficulty.

Curative Treatment. — The chemical treatment consists in placing
the parasites in contact with substances which have an injurious
effect on them.

Insecticides are u>ed to kill insects ; anticryptogamics or fungicides
to combat parasitic fungi. To get the best results from the use of
chemical reagents, it is desirable to know the properties of the curative
agents and the right method of using them.

Examination of Curative Agents. — The chemical products
utilized in the struggle against parasites ought to respond to the
following different requirements : (1) To destroy the parasite or arrest
its evolution. (2) To be more poisonous to the parasite than to the plant.
(3) To preserve their poisonous properties for a certain time and to
adhere sufficiently to the organ of the plant. (4) To enter into inti-
mate contact with the parasites or their elements of propagation.

Action of Chemical Products on Parasites. — Most of the
chemical agents employed against parasites act chemically on their
vital substance. The most active are in general those which form
inert derivatives with it, which precipitate the albumen or which
modify the plasma ; such are corrosive sublimate, formol, copper salts,
phenols, etc. They thus arrest, temporarily or definitely, the evolution
of parasites or their elements of propagation. In the case of bacteria
the phenomena of intoxication may be more easily observed. It is
then observed that their evolution and reproduction are arrested by
the formation of an inert layer around them. It suffices often by
prolonged washing of these bacteria with appropriate liquids to re-
move the immobilizing layer and to allow them to resume under normal

Trayislator's Note, — As many as 150 wire-worms have been trapped by rape
cake, etc., 2-3 inches underground close to one hop hill by Whitehead.

INTRODUCTION. \)

conditions the sequence of their uninterrupted evolution. The chemical
agents do not therefore necessarily kill the parasites and their organs
of propagation ; often they only paralyse for a certain time the
normal evolution of the parasite. The more the therapeutic agent is
capable of insolubilizing albumen, or of modifying the substances
constituting the cells, the more active it is. Wuthrick (" Zeitschrift fiir
Planzen krankeiten de Sorauer," 1892, p. 81) examined the comparative
action of various substances on the different spores of fungi. His
researches, in which mention is made of the relation which exists
between the molecular weight of the chemical products and their
action on parasites, leave no room for doubt on the subject of the
sinihlarity of the action of various chemical products on the vital
substances of parasites. Other poisonous chemical products act on
parasites, some in virtue of their properties as solvents of organic
matter, such as the caustic alkalies, alkaline soaps in aqueous or
alcoholic solution, and certain acids, others by their dehydrating
action exerted chiefly on the medium on which the parasite lives.
No parasite living in an aqueous medium can develop except when
the amount of water contained therein does not descend below a
minimum. A disease may be stopped if the conditions of existence
of a parasite be modified in this direction. Other chemical products
are asphyxiants : impalpable powders, and oils and fats ; they obstruct
the respiratory passages.

Action of Chemical Products on Plants. — The chemical pro-
ducts used to combat plant diseases have all, to a certain extent
unless insoluble, an injurious action on plants. The plant is gener-
ally less sensitive to chemical agents than the spores of fungi, and
more sensitive than insects, their larvae, and their eggs.

Liquids Spread on the Surface of Plants may penetrate therein
by endosmosis, whilst gases and vapours do not appear to be, or ai*e
with difficulty, absorbed by the plant.

It follows that the treatment of plant diseases may be preferably
done —

1. By products under the for yn of gas or vapour.

2. At a time when the organs which joermit endosmosis no lo7iger
exist, and lohen the cellular activity of the plant is reduced to a mini-
mum, that is to say, in unnter.

At that time of the year chemical agents of any degree of concen-
tration may be used without injuring the plant, whilst in summer
infinite precautions must be taken not to destroy the organs of the
infected plant at the same time as the parasites. Treatment by gas is
very efficient, and is becoming more common every day, whether it
be the treatment of the part of the plant above ground (aerial), or of
that underground, the roots being infected as frequently as the stems
by parasites injurious to their normal evolution. With this end in view
injections of carbon disulphide, petroleum, benzene are made into the
soil, and by enclosing [clochage) the part above ground, an atmosphere
may be created charged with sulphurous acid, carbon disulphide,
prussic acid, nicotine, etc. When solutions or emulsions of the
chemical agents are to be used in spring and in summer, the sensitive-

10 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

ness of the plant towards these ingredients must be known. Each
plant possesses its own particular sensitiveness towards substances
poisonous to parasites, and it is desirable to use these substances, in
each instance in an appropriate degree of concentration. When the
sensitiveness of the plant is greater than that of the parasite, there is
reason to abstain from the use of such substances, or it is then necessary
to follow the spraying by washing with pure water, only giving them the
time required to act on the parasite. This latter precaution allows
the use of strong doses of toxic substances, doses which would kill the
plants if the washing did not intervene to prevent prolonged contact.

Indispensable Properties of the Chemical Agents. — The
chemical agents should be of such a nature as to guarantee reaching
the parasites. Certain insects and their larvee are covered with hair
and down, or even with a coat of wax, which prevents aqueous solu-
tions from reaching them. The insecticides which should be
employed in such cases are alcoholic, ethereal, or oily solutions,
soaps and caustic alkalies having a solvent action on the organs of
protection, and capable of moistening them, so as to let the toxic sub-
stances penetrate as far as the sensitive organs of the insect. The
treatment should often be curative and preservative, and it is then
necessary that the substances used should persist for the longest time
possible on the surface of the plant. This problem would be easily
realized if rain did not remove in a short time the deposit of substances
created by spraying. Attempts have been made to protect plants
from the effects of the natural washing by the use of substances of
poor solubility in water, and with a perfect adherence to the organs
of the surface treated. The agents only slightly soluble in water
spread on the surface of the plant, m the form of bouillies, form
deposits which the rain cannot remove owing to their own adherence,
or to an adherence acquired artificially, by the incorporation of gluey
substances, insoluble in water (silicate of soda, saccharates, soaps,
gelatine, rosin). But care must be taken not to use too insoluble
substances and in too great quantity, for there is a risk of covering the
whole of the respiratory surface of the leaves with a layer rendering
the exchange of gases impossible, which, if it does not cause asphyxia,
produces at least an annoying disturbance in the growth (evolution).
The insoluble, or the only slightly soluble products are, in general, of
greater service than the soluble products. In addition to their less
injurious action on the plant, they persist longer on the surface of the
vulnerable organs and their action is of longer duration.

The insoluble products are intended to poison insects through the
stomach. A slight layer of arseniate of lead, or of arsenite of copper
(Paris green), ^ on the leaves penetrates into the stomach at the same
time as the leaf and kills the insect. In the case of cryptogamic
parasites, slightly soluble substances are used, which in contact with
the dew causes it to become toxic, owing to the traces of poison which
it has dissolved, and to kill the spores, which require its aid for their
evolution. Briefly, it is necessary in each particular case to choose

' Note by Tranalator. — Arsenite of copper is not Paris green but Scheele's green.
Paris green is our emerald green, the iiceto-arsenite of copper.

INTRODUCTION. ill

the appropriate remedy and to use it with discretion. It is the most
difficult side of vegetable therapeutics. The therapeutic store contains
a great number of pi'oducts the action of which is analogous. Those
which can be usefully employed can be reduced to a small number.
The most interesting are carbon disulphide, bouillie bordelaise/ lime,
sulphur, sulphate of iron, sulphuric acid, emerald green, soap-emulsions
of petroleum and alcohol, tar, prussic acid, tobacco, and nitrobenzene.
The greater number of the chemical products which have been the
subject of .experiment against the diseases of plants are, nevertheless,
dealt with in this treatise, and deductions drawn from the aggregate of
the results obtained by the experimenters. The results which have
been published are so very different, and the opinions expressed so
contradictory, that the author has been obliged to control the facts
by personal experiment before expressing au opinion. Laboratory
experiments do not always permit of the conclusion that their results
will be confirmed in actual practice ; parasites have natural means of
protection which are awanting in the laboratory, but which enable
them in a natural state to escape very often from the deadly action
of the agents used. Experiments, therefore, to which most weight
is attached are those made in practice. According to their mode of
action and their nature, chemical agents are used and applied in very
different ways.

Methods of Using Chemical Products in Treating the Diseases
of Plants. — Insecticides and anticryptogams are used in three forms :
(1) As gas. (2) As powder. (3) In the state of solution or suspension in
a liquid vehicle. Use of Chemical Agents in State of Gas. — Gases are
used in closed spaces under a cloche''^ or in the soil. For this pur-
pose there is utilized either liquids which evaporate at the ordinary
temperature or solid products which disengage gas by heat, combus-
tion, or chemical decomposition. In any case it is necessary that the
gas mix perfectly with air and reach all the corners of the area to be
disinfected. In closed spaces that is comparatively easy, in the soil
it is more difficult to realize.

Underground Treatment. — Injections of volatile liquids are made
in the soil at suitable depths by means of an instrument called the pat
injector (fig. 5, p. 63), w^hen by sprinkling the soil with water the gas
which is disengaged is enclosed. When such treatment is carried out
with the necessary care, so as to avoid the contact of the liquid sub-
stance with the roots of the plant it yields perfect results. But diffi-
culties are encountered due to the nature of the soil. If it be easy to
disengage toxic gases in a friable soil it becomes difficult to spread the
gases uniformly in a compact wet soil. Gases circulate with difficulty
through certain soils, and are not retained long enough in others.
Water creates an impenetrable barrier to the circulation of gases.

^ The translator has retained the original French term throughout. The usual
English rendering of the term as " Bordeaux mixture " being, in his opinion, a poor
rendering. All bouillies are perfoi'ce mixtures, but only a few mixtures are bouillies.

- Note by Translator. — A bell- or dome-shaped glass vessel familiar to those
who dab. le in the French style of gardening recently resurrected in Great Britain
but well known to London market gardeners at least 150 years ago who even in
those early days used them by the hundred.

12 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

The gases produced in the soil should not enter into reaction therewith
and be fixed by the substances in the soil. From this point of view
carbon disulphide is the best substance. Other substances, such as tar,
petrol, benzene, sulphuretted hydrogen, are retained by the capillarity
and chemical action of the soil which often energetically opposes their
distribution. To avoid failure it is well to give the preference to
insecticides in dilute solutions in winter, and to volatile insecticides
in summer, when the soil is dry.

Aerial (or above ground) Treatment by Oases. — Clochage, or
treatment in a closed space, gives the most certain results, and does
not exert an unfavourable influence on the development of the plant.
Highly poisonous gases may be used against parasites, because they do
not generally have a deadly action on the plant, especially when con-
tact with the plant is not prolonged beyond measure, which result is
obtained by aerating after a predetermined time.

Clochage is used to disinfect the vine by sulphurous acid. The
stock is covered with a cloche made of a tun (cask) cut through the
middle, or with a zinc receiver fitted with two handles. Under the
cloche the gas is disengaged by combustion or by chemical decomposi-
tion of certain salts : sulphur is burnt, or potassium cyanide is decom-
posed by sulphuric acid. The operation is finished in ten minutes.
In greenhouses or in closed spaces made around fruit trees or against
espaliers with waterproof awning, the operation is performed in the
same way. In all case^ where disinfection by gas is possible, it ought
to be applied as a process sure to disinfect without injuring the plant
treated. It is the only process applicable to food warehouses. Treat-
ment by gas is always curative. When this treatment is not applicable
recourse is had to treatment by boiling water, or solutions of toxic
substances, emulsions, or pulverulent products.

Scalding or treatment by boiling water finds a very extended
use in winter to kill by heat all parasites and their germs lodged
along the trunk of a plant. But that is a winter treatment which
cannot be applied in summer, the delicate organs of the plant not
being able any more than the parasites to support contact with hot
water. J |

Use of Chemical Agents in the Form of Powder. — Non-
poisonous but asphyxiant powders are used such as they are ; toxic
powders are reduced more or less according to the intensity of their
insecticidal or sporicidal capacity with flour, talc, chalk, or any other
inert matter, finely divided and cheap. The powders are projected on
to the plant by means of bellows called sulphurators (figs. 3 and 4,
p. 47). Powders may be projected where liquids cannot penetrate.
Liquid treatments are sometimes alternated in the struggle against
stubborn diseases with pulverulent treatments of the same composition.

Use of Chemical Products in the Liquid Form. — Poisonous
substances in a state of solution are used in both the external and
internal treatment of plants. In the external treatment the poisonous
substance is spread on the plant, whilst in the internal treatment it is
introduced into the juice, either by causing it to be absorbed by the
roots or by injecting it into the trunk. External treatment is most

INTBODUCTION. 13

generally used, and it is from it that the most successful results are to
be anticipated.

External Treatment : Liquids. — Solutions, bouillies, emulsions
are much more used than gase'? and powders owing to their easy use.
These preparations are distributed by the spraying machine (figs. 8-12)
when the treatment is general, and by the brush when it is local. The
efficiency of the treatment by liquids depends to a great extent on the
mode of application. The substances should be projected in a finely
divided state, best in the form of a mist, because it is less important to
accumulate large quantities of substance in a given point than to
spread a little everywhere in a uniform manner, above as well as below
the leaves, on the twigs and on the trunks. The largest number of points
of contact between the spores of the fungi or the insect and the poisonous
solution must be secured. The appliances which attain this object
are the spraying machines which have reached a high degree of per-
fection. The liquid preparations must possess a certain degree of
concentration to be active. It is injurious to increase this concentra-
tion, and dangerous to diminish it. When a liquid preparation has a
poisonous action on the plant, or if it has no adherence, these draw-
backs may be obviated by multiplying the treatments with a weaker
preparation. It has been found that it is better to diminish the
strength of the applications and to increase the number of spray-
ings, for it is the abundance of these rather than the strength of
the preparation which forms on all the organs, in proportion as they
are developed, an extremely thin layer of a toxic substance capable
of preventing the development of spores or of poisoning parasites.

Experience has proven that periodically spraying at short mtervals
with weak bouillies yields far better results than a single annual
spraying with concentrated bouillie as formerly practised. The single
spraying with a 4 per cent copper sulphate bouillie used some years
ago has been replaced by three to seven treatments with bouillies
prepared with 0*5 per cent of copper sulphate. Although the total
amount of copper spread on the surface of the plant be mostly less
than formerly, the result is better, because all the surface of the plant
remains covered with a very thin pellicle of hydrated oxide of copper
of which a trace dissolved in rain water or dew suffices, as has been
found, to kill the spores which are germinated. This new process is
the more efficient because it especially guarantees against disease all
the young organs of the plant, which being more tender and more
aqueous, are more easily invaded by parasitic fungi and have there-
fore a greater receptivity for cryptogamic diseases. The perfection of
the treatment is, therefore, an element as important to secure success
as the properties of the product. When anti-cryptogamic substances
are used, it is necessary to bear in mind that the external treatment of
a plant cannot destroy the mycelium of the fungus which has penetrated
into the plant, and its multiple ramifications in the interior of the
latter are perfectly protected from all outside spraying. The ex-
ternal treatments are intended to destroy the organs that disseminate
the disease, the conidiophores and isolated spores, and thus prevent the
extension of the disease to other plants. If for any reason the treat-

14 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

ment has beea deferred and the disease has assumed a great extension,
it is well to remove before spraying the parts of the plant most seriously
attacked and to burn them ; that is a surgical complement to the
chemical treatment which may be of great service and which must not
be neglected if one be anxious to suppress the disease. It is well to
say that neglect of one factor may compromise the results of the
treatment by liquids and rob the experimental effort of any beneficial
result.

I Internal Treatment. — From analogy, with the treatment of
human diseases, attempts have been made to introduce into the sap
of the plant toxic elements, intended to be carried through the plant,
and to destroy the mycelium of fungi which have invaded it, or to
kill xylophagic insects and those which suck the sap. The experi-
ments of Laffitte and Henneguy have shown that a substance
dissolved in water, absorbed by the roots, may ascend to the leaves
and reach the extremities of the tree if it does not form insoluble
compounds with the constituent elements of the sap ; however, the
greater number of salts yield with the plasma insoluble derivatives,
which prevent their entrainment by the sap towards the part of the
plant attacked by the parasites. Numerous experiments have been
made in this direction to combat the phylloxera. The method used,
it must be confessed with mediocre success, consisted in making a
hole in the vine stock from above downwards by a gimlet, and in
introducing therein the chemical agents such as calomel, camphor,
potassium sulphide. These were the first experiments carried out
under very bad conditions, nevertheless carbolic acid, used by Green
against lice, prussic acid against bugs, have given appreciable results.
The first fortunate results were obtained by Mokretzki with injections
of a dilute solution of sulphate of iron, and nutritive elements which
he injected into the sap to cure chlorosis. These were crowned with
complete success. But they must be executed in such a way that
the air cannot penetrate into the wound, and a slight pressure is
required to enable the liquid to enter into direct contact with the sap
of the plant. However, when Mokretzki tried sulphate of copper under
the same conditions, his experiments were a failure. It is possible,
however, that organic salts of copper soluble in the sap may behave
as indifferent salts, especially if used in small doses, and produce the
satisfactory effects on the health of the tree given by dilute solutions
of sulphate of iron, and by sprinkling the soil with sulphate of copper.
Metals are capable of forming organic salts, which no longer precipitate
albumen, and, injected into the sap, may behave in quite a different
manner from the corresponding inorganic salts. These organic salts
have found multiple applications in human therapeutics, and it is to be
supposed that their use will extend in the domain of vegetable thera-
peutics. The internal treatment discovered by Mokretzki will
perforce extend further when it has been determined under what form
poisons can be incorporated with the sap, and especially in what
degree of concentration they should be used. These remedies will
form a powerful instrument against all sucker-lice, and will be capable
of arresting the internal evolution of the mycelium of parasitic fungi.

INTRODUCTION. 15

But vegetable therapeutics will often yield imperfect results in spite of
aill the attention brought to bear in the application of appropriate
remedies, for it is difficult to dislodge or to destroy in the interior
and on the exterior of a plant without injuring it the parasites which-
develop there, surrounded by the very efficient means of protection
which nature has given them ; and if we insist on this axiom, that a
plant disease cannot be cured, but that it can only be diminished or
its extension prevented, the important role which preventive methods
play in the struggle against plant diseases will be understood.

Prophylaxy. — Prophylaxy is that part of medicine which deals with
the means of guaranteeing against disease and preventing it. Knowing
the cause or the causes of the diseases it is possible to protect plants
efficiently against them. The knowledge acquired as to the reactions
of the organism, and the means by which it naturally arranges to
defend itself against disease, have enabled prophylaxy to utilize
physiological processes instead of agents destructive to parasites. It
is necessary to differentiate between therapeutic prophylaxy and
hygienic prophylaxy. The former utilizes therapeutic agents, surgical
processes as well as antiseptic insecticides, fungicides. The latter
employs dietetics, stimulants of growth, rational feeding, selection of
vigorous and hardy species. Medicine in its application to plants is
in fact as complicated as when applied to man, and it is not surprising
to see it necessary to take at the same time prophylactic and thera-
peutic measures in order to have crops free from disease.

Therapeutic Prophylaxy. — When the cause of a disease is known,
its evolution and that of the parasites which produce it, it is com-
paratively easy to find the means of checking it by preventive
measures. These treatments may be very often carried out at a time
when the plant can bear them with impunity ; in winter when the
delicate organs have disappeared and when the sap is at rest. One
must never wait until a disease manifests itself, even if the possibility
of its appearance is not absolutely certain. Preventive treatments if
they are not always capable of removing all the effective and adjuvant
causes of disease will minimize them. When the cause is a parasitic
one, the object pursued is not to destroy all the parasitic elements, but
to reduce them to their normal or natural number increased by our
methods of cropping. In these conditions, parasites having always ex-
isted and their complete destruction being as chimerical and as useless
as a complete disinfection of the air which we breathe, with the object
of destroying all microbes, disease is no longer to be feared, because it
no longer causes us appreciable injuries.

Preventive Surgical Treatments. — Operatory medicine may be
of great assistance in the prevention of plant diseases ; in fact the
suppression of everything which may transmit a disease from one year
to another is often capable of giving radical results — excision of the
diseased parts, removal of branches attacked or bearing spores or eggs,
washing of the bark of the trunk and branches to suppress refuges
formed by mosses and lichens for acari, aphides, and coleoptera. In-
tervention by naked hand plays a role not less important, by the
eollection and suppression of the old organs of plants, leaves, and

16 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

rotten and wormy fruit on which receptacles containing the spores of
fungi serve as refuge to grubs and chrysales and as shelter to masses
of insect eggs. The destruction of the parasites and their hiding-places
by this simple means causes them to disappear completely after a
certain time.

Birdlime traps preventing insects and their larvae from reaching
points that they might ravage, are likewise useful auxiliaries. The
most usual trap is the ring of tar or of birdlime with which the trunk
of trees is surrounded. The going and coming of apterous parasites
between the leafy portion and the soil being along the trunk, the ring
of sticky substance drawn round the trunk is intended to stop these
often daily journeys and to retain all these parasites stuck fast. An
examination of the habits of parasites demonstrates that almost all
are forced to use this road ; some to seek a refuge in the soil for the
night, others to ascend nightly from the soil in which they had
taken refuge during the day. Thus the grub descends along the
trunk to place itself as a chrysalis in the soil, and the butterfly, even
when it is not apterous, ascends along the trunk to deposit the eggs
which weigh down the female. The grey worm and many moth
grubs go every morning to find a refuge in the soil, to re-ascend the
trunk in the evening. This method, now very common, gives perfect
results. In arboriculture it is a powerful auxiliary to the liming of
the tree, but it is necessary to watch that this sticky substance pre-
serves its adhesive qualities and to renew the ring when these have
disappeared. Young fruit trees being sensitive and liable to perish
after an application of a ring of tar or birdlime, it is well to fix round
the trunk a strip of cardboard well fitted and to coat it with the sticky
substance. The same result is thus obtained without injuring the
health of the tree.

Preventive Treatment by Means of Chemical Agents. — The
general conditions as regards the properties of the chemical agents
used in the preventive treatment of plant diseases are the same as in
the curative treatment. The chemical products must destroy the
parasites and be more poisonous to it than to the plant ; they must
adhere and preserve their poisonous power for a certain time, and
enter into intimate contact with the parasite or with its elements of
propagation. When such treatments are applied, as is often the case
during the repose of vegetation, the comparative insensibility of the
plant enables them to be used in doses, deadly to the parasite without
injuring the plant. Most fungi living protected in the interior of the
tissue are sheltered from the action of the poisons spread on the
surface of the organ attacked, and are evolved in spite of the curative
chemical treatment. The important point io plant diseases is to
destroy the spores which propagate the disease. To attain this result,
different spores must be attacked by different methods. If it be a
case of destroying winter spores, very energetic treatment must be
applied in winter, for these spores have an extraordinary power of
resisting chemical agents. If it is a case of killing summer spores,
which, on the contrary, are very sensitive and delicate, a treatment
with dilute, anticryptogamic solutions will suffice. Preventive winter

INTEODrCTION. 17

treatment can thus be distinguished from preventive summer treat-
ment. Preventive winter treatment consists in destroying by chemical
agents all parasites, and the elements of their propagation. To obtain
this result the trunks and branches are painted or washed, after a
mechanical dressing with milk of lime, concentrated copper bouillies,
10 per cent solutions of sulphuric acid, hot concentrated solutions of
sulphate of iron, boiling water, petroleum, and pure carbon disulphide.
These chemical agents, used in such a high degree of concentration,
do not injure the plant in winter, and permit of a radical destruction
of the parasites. These preventive -vvinter treatments are, generally,
sufficient to prevent the diseases from appearing in the following year,
especially when care is taken to destroy the decayed organs scattered
around the plant, and to disinfect the soil, the dung, and the seed.
This last precaution is of an undoubted utility in preventing the
diseases of plants cropped annually, and the methods usually em-
ployed have now attained a gi'eat degree of perfection. Moreover,
it is necessary to destro}' wild plants of the same species, which ai-e
preferred by the parasites which it is desired to destroy, plants which
form seats of infection which are necessary to the cyclic development
of certain parasitic fungi, such as the rust of cereals, which search
for nurse plants of different species necessary for their normal evolu-
tion, and the destruction of which brings about the radical suppression
of the pai-asite. These plants are the barberry and boragineae (''^ p. 22).

Preventive Summer Treatment. — In spite of preventive winter
treatments they must be completed by summer treatments. \Yorking
so that the vulnerable organs of the plant are always protected by a
fungicide very slightly soluble in the dew, the plant is prevented
from succumbing to the incessant attacks of the spores, which the
atmospheric currents lead to it. It is a case of very small doses of
anticryptogamic agents, which suffice when the treatment is continued
during the whole period in which the disease is to be feared. Weak
injections of carbon disulphide in the soil and periodic washings of the
stock with dilute solutions of potassic sulpho-carbonate have given the
best results in the struggle against the phylloxera, without destroying
all the parasites they so far diminish their number that they can nO'
longer injure the plant. Sulphating every yeav with weak bouillies-
yields analogous results and enables the trees to develop normally.
Along with the rational and periodic use of chemical agents intended
to kill the greater part of the germs of cryptogamic diseases and insects,
it is well to use stimulants to furnish rational nutriment to the plants
and to pay attention to their hygiene.

Hygienic Prophylaxy. — Vegetable therapeutics does not consist,
in fact, entirely in the struggle against the effective factors, but it
ought likewise to suppress the adjuvant causes. Plants are restored
like animals by the art of healing regarded in its widest scope. Hygiene
which plays so great a role in human prophylaxy ought to receive
equal attention in the case of vegetables. This hygiene is based on
a knowledge of their organs, and their mode of gi'owth, on that of the
environment where they live, and the climatic conditions which
favour their development, and the mineral elements indispensable to

2

18 INSECTICIDES, FUNGICIDES, AND WEED KILLEKS

them. It is necessary to remove bad influences from plants, and
to supply them, if need be, in a regular and abundant manner with
the nutritive elements which they require. If it be asserted that a
disease can be transmitted to a plant by artificial infection when
placed in a laboratory where it has not all its means of reaction, it
must not be concluded therefrom that this same plant will always
succumb to this parasite in surroundings favourable to its develop-
ment and in good hygienic conditions. Owing to a special immunity
which is not acquired, except under certain conditions, the plant, on
the contrary, will be able to resist the attempts .of invasion by
the parasites and will issue victorious fx'om any struggle in all
instances.

Most cryptogamic parasites ai'e incapable of attacking the living
vigorous and healthy cell. Certain insects, even xylophagic, such as
the Scolytes, only attack a sickly tree, the intense motion of the sap
being injurious to the development of their larvae. On the other
hand, most parasites find an easy shelter in the plant when the latter
is enfeebled by an adjuvant cause, or when organs capable of being
invaded have been laid bare by a wound.

Stimulants of Growth. — We know from the researches of
Eaulin, Nageli, Pfeiffer, Eichard, and Ono the favourable influence
which certain metallic salts absorbed by the sap can exercise on the
health of plants. Salts of iron, copper, mercury, zinc, nickel, cobalt,
manganese, lithium, fluorides, and arsenites have in a certain dose
a stimulating action on the vital functions of the plant, analogous to
that which arsenious acid exercises on our own organism. The use of
these stimulants may often be a useful means of stimulating the
vigour of the plant, and of rendering it more capable of resisting
cryptogamic diseases.

Nutrition. — The researches of Liebig, Boussingault, Deherain, and
■others have shown that the development of plants depends greatly on
the mineral elements which they find in the soil, and nothing is
more easy than to supply them when the soil is deficient therein.
The result of these researches has been intensive farming, which by
supplying in great abundance the elements necessary for the growth
of plants has rendered it possible to double and triple the yield of
crops. Encouraged by such success we have learned to prepare an
exact account of the elements indispensable for each plant crop by the
analysis of its ash, of the elements of the soil, and taking into account
the nutritive elements that the preceding crop has removed and add-
ing to the soil the elements in which it is deficient. It has been ob-
served, however, that the plants obtained as a result of intensive manur-
ing were more subject to diseases, and that such assumed a dangerous
character. The great delicacy of the plants constituted a more favour-
able inedium for their evolution, however little the climatic conditions
favour their development, and predispose the plants to infection. It
must be admitted that the intensive culture now practised does not
produce a normal condition of the plant, but a cultivated condition,
and that the parasites have acquired a greater vigour and become
more virulent owing to the great richness of the plant in nutritive

INTEODUCTION, 19

elements. Too abundant feeding of our cultivated plants has created
a danger which the farmer of to-day must face.

Formerly the method of cultivation gave a mediocre and irregular
yield, and the farmer did not disturb himself. There was in the opinion"
of our fathers, which was fatal, good years and bad years. Diseases
existed even then, but they did not in their opinion contribute much to
the annual variation in the yields. In our days they have a much
more important role, for the cultivation expenses being higher, owing
to increased attention and to the use of various chemical manures, the
yield ought to compensate for the pecuniary efforts expended.

Exhaustion of the Soil. — In spite of the annual supply to the
soil of the elements required by the plant for its intensive growth, it
is found that a time comes when the plant ceases to pi'ofit from the
nutritive elements and thrives no longer. This is due to the fact
that the enemies of the cultivated plant are accumulated in the soil.
The ancient farmers attributed this condition to the exhaustion of the
soil, and intercalated the bare falloic between the crops when this ex-
haustion manifested itself. In bare fallow the fields remained several
years without a crop. Without being aware of it they thus abolished
the provision stores of the parasites, and these disappeared or became
reduced to their natural proportion. By this time the field had
acquired new vigour, and might be again cultivated. This method
cannot be adopted to-day, because it is a loss of time and money.
The alternation of crops or of different plants having consequently
different parasites succeeded each other, and where the same plant did
not appear in the rotation except at long intervals it caused a
great improvement in this condition of the soil. Kotations would
give perfect results in the absence of polyphagia parasites : Nematoides,
Elaterides, grey and white worms which attack all our crops indiffer-
ently, and the exaggerated multiplication of which operates through-
out the most different crops ; the spores of Ustilaginece (smut, bunt,
etc.), which resist the weather for several years, excepted. Against the
exhaustion of the soil from the exaggerated development of these para-
sites no efficient remedy exists, except disinfection of the soil by car-
bon disulphide. This must be done either in a complete manner,
and in massive doses every ten years, or in small doses each autumn.
It frees our cultivated fields from all the parasites which our methods
of cropping have allowed to accumulate in too great number. This
method finds more adherents every day, as it enables rotations to be
dispensed with and to cultivate the same plant intensively for several
years in succession. Artificial manures as well as the metallic salts
intended to stimulate the growth of plants should be used with dis-
cretion, so as not to predispose the plant by a modification of the sap
to certain diseases which formerly it escaped. Laurent found that
bacteria, not parasites of the potato in a normal state, might invade
it after manuring with lime. The Jerusalem artichoke becomes less
resistant to the Sclerotina Libertiana ^ after phosphatic manure. These

^ Note by Translator. — Fungus which ravages potato, haricot beans, hemp,
ououmbers, swedes, zinnias, petunias, chrysanthemums. Remedy. — Apply soot or
lime to soil.

20 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

two cases are easily explained, the first by the fact that the bacteria
seek an alkaline medium created by the lime, the second by the fact
that the Sclerotina seeks, on the contrary, an acid medium created by
the acid phosphate. Intense nitrogenous manuring favours the de-
velopment of phytophora. It is thus essential to avoid the use of
manures which may place the plant in a state of subjection in the
struggle which it has to sustain against inimical factors.

Choice of Species. — One species may be more subject to disease
than another, and possess a predisposition for certain pathological con-
ditions. That occurs when the conditions favourable to the develop-
ment of the plant are also those which favour the evolution of parasites
at the time when the plant is young and possesses delicate tissues
just when the parasites are most virulent. Care must be taken in
sowing a plant that the germination of the seed does not coincide
with the virulent development of the parasite, with the ripening of the
spores of fungoid enemies, or the hatching of the eggs of certain
insects. It suffices to sow a little earlier or later. But in spite
of all that can be done to eliminate parasites, they none the less exist
and ravage the tissues. The cells of the plant, like those of the human
organism, react, and it is found that after this constant struggle they
undergo certain modifications which are opposed to the develop-
ment of the parasite, and the plant acquires a certain immunity. It is
acknowledged that the deposits of tannin and other materials in
certain cells and the concentration of the sap are conditions resulting
from the struggle of the plant against insects, and destined to oppose
an unsuitable medium to any attempt of development. Plant
diseases do not, therefore, depend solely on the presence of a parasite,
but as much on the conditions predisposing the plant to a want of
reactive energy, and it has been found that this predisposition was an
atti'ibute of certain species or cei'tain varieties.

Meteorological Influences.— Although we are still badly equipped
to struggle against atmospheric influences, each day brings new dis-
coveries from which agriculture knows how to benefit. Thus hail
and morning frosts may be effectively prevented — hail by artificial per-
cussion of the atmospheric layer where hail is formed, morning frosts
by means of artificial clouds. Without neglecting therapeutic
methods it is necessary to take incessant prophylactic measures to
prevent the evolution of diseases and their propagation, to treat the
seed, the plant, the soil, and the crops by toxic products, to destroy
the plants invaded, which form hot-beds of infection, to avoid the im-
portation of plants from districts notoriously infected. Effoi't must
be made to apply a general treatment to the plant, to remove as far
as possible all conditions favourable to the growth of parasites. The
hygiene of the plant must receive careful attention ; sowing retarded
or advanced ; the plants protected against eventual frosts and hail ;
drain and lime the soil against humidity, the great predisposing cause
of cryptogamic diseases ; apply appropriate strengthening manures ;
choose hardy species obtained by crossing or by selection, and create
new varieties combining great resistance to plant diseases with the
necessary properties of production. So that the struggle may be sue-

INTRODUCTION. 21

cessful measures must be general. Each cultivator ought to be able
to work in full knowledge of the cause ; he ought to be able to obtain
information on the nature of the diseases which he observes, and the _
means which should be used to combat them. All interested should
be able to act simultaneously over a large extent of territory, a con-
dition which will alone crown any individual effort with success.
There now exist in certain agricultural centres laboratories where all
questions are solved gratuitously. These institutions are intended to
help cultivators, and to supply them with the means of combating the
diseases which ravage or menace their crops. The movement in
favour of these institutions where all phytopathologic questions are
studied, and which centralize all the observations made by interested
parties on the diseases, the presence of which they have observed, is
especially accentuated in Germany. When the prosperity of a country
is threatened by the appearance of a disease and by its generalization
it is necessary to take general measures. These are made imperative in
many cases on cultivators by arretes [an arrete is possibly equivalent
to our Order in Council].

If one considers that the damages caused annually to French
crops bj" injurious insects, according to the calculations of authorized
persons, amount to several hundreds of millions (a million francs =
£40,000), that the loss due to cryptogamic disease reaches a still
higher figure, an idea can be gainsd of the great necessity there is to
generalize the methods of struggling against parasites, and the neces-
sity of simultaneous action by all under the control and the direction
of official agents. The first order dealing with the protection of
crops against injurious insects is that of the Parliament of Paris of
date 4 February, 1732 ; then came the Act of the 26th Yentose Year lY,
which rendered obligatory the destruction of grubs in general (modi-
fied by the Act of 24 December, 1888). It especially prescribes the
destruction of the grubs of Liparis chrysorrliea, the brown-tailed moth,
the agglomerations of which in winter and in spring form silky
wrappers between the branches of fruit trees. The Order declares that
" After the date fixed by the Prefect, farmers who have not submitted
to the prefectoral order, will be liable to a fine of six to fifteen francs,
and obliged to pay to the administration the expenses incurred by it
in grubbing on their domains ". The panic created by the appearance
of the phylloxera in 1863 was followed by an effect which has made
itself felt in all branches of cultivation. Examination Commissions
were formed, a National Agronomical Institute was founded in Paris.
Chairs of Agriculture were created, new laws were passed, the Ad-
ministration is working with equal solicitude at all cultural pests,
and it has enacted the measures required to cope against the ex-
tension of diseases. As a consequence of the International Phyl-
loxeric Convention held at Berne, an order of 10 September, 1884,
interdicted the exportation and importation of rooted-up stocks and
of sprouts (shoots). Then the destruction of insectivorous birds has
been forbidden. Cultivators too often misconstrue their precious
collaboration in the struggle against parasites.

Societies for the destruction of parasites have been formed in

22 IXSECTICIDES, FUNGICIDES, AND AVEED KILLERS.

cantons, bureaux of gratuitous information opened, enabling interested
parties to know the disease which ravages their fields, and how to
prevent it, or combat it, in the most economical conditions. These
syndicates are cantonal or communal ; their bye-laws must have pre-
fectoral sanction ; their budget consists of the subscription of adher-
ents, individual subscriptions, communal, and Government grants.
The Council of Administration places the instruments, the insecticides,
and the anticryptogamic products at the disposal of those interested ; it
publishes the right times to use preventive or curative processes, and
gives the detail of the methods to follow ; it directs itself at propitious
seasons all the operations tending to the destruction of parasites,
and to restore the fertility of the fields through the intermediary of an
executive committee which has the direction and the responsibility of
opei'ations. Societies have been formed against the ' Apple-blossom
Weevil," against the may-bug (cockchafer, Hanneton). The annual
results obtained by some may-bug societies in a year are as follows : —

Seine et Marne . destroyed 282,500 kilogrammes.^

Brie Comte Eobert ,. " 101,000

Aisne ... „ 13 thousand million cockchafers.

Bernay dans Eure ,, 148,500 kilogrammes.

These figures are eloquent. However, if they show the useful inter-
vention of the syndicates established for the destruction of injurious
insects, they enable us to foresee the results that these syndicates would
be capable of obtaining if their programme was a broader one, and
comprised all which concerns vegetable pathogenesis, prophylaxy, and
therapeutics. Common action organized in this way under wise
direction will be a perfect method to combat agricultural pests and
blights so long as no medical specialists for cultivated plants, with the
same rank as veterinary surgeons, exist. But there is much ground
to be traversed before getting so far as that ; the science which should
guide these medical specialists is only in its infancy, and the most
important problems are still to be solved. It is, however, necessary to
reach this goal so that this younger sister of medicine applied by
special practitioners may render inestimable services to cultivation
and increase the prosperity of the country.

' Note by Translator. — From the peculiar style of numeration of French
writers it is impossible to say whether '28*2, -500 means 282^ kg. or 282,500 kg., that
is 282^ metric tons, which seems impossible. Yet even in this country so gi'eat
were the ravages of Bombyx chrysorrJiea in 1782 that prayers were offered up
in some churches for deliverance from the scourge and Is. per bushel was offered
for the webs, and bo abundant were they in Cl'ipham parish that 80 bushels were
collected in one day in that parish alone !

* Note by Tnntshitor (p. 17). — The tendency of present-day authorities is as
regards evolution of rust of wheat to discard the theory of an intermediate host
(barberry) in favour of Eriksson's theory of hereditary infection.

CHAPTER I.

COLD WATER— SUBMERSION— SPRAYING HOT WATER—
IMMERSION— SPRAYING— HYDROGEN PEROXIDE.

I. Water, H,0. — Water is necessary to the plant (1) as food, (2) as
solvent of nutritive matters. To a certain extent crops increase in
proportion to the water used in the cultivation. Want of water
injures the plant, causes deformities, anomalies, and troubles of which
the chief are : ])ilosis, excess of hair on the stem and leaves, formation
of tart substances (piquants), stony pears, lignification of the roots ;
nanisme, potatoes with filiform rhizomes, fall of flower-buds, pre-
mature drying of the leaves, honej^-dew, barren flowers in the case of
cereals. But on the other hand, if water is useful and even necessary
to the plant, in excess, however, it is injurious thereto. In the latter
case it is the cause of the following diseases : frisolee of the potato,
rhytidome of the potato, germination of the same plant before potato
lifting, hollow fruits, stems and roots, prematui'e formation of seeds,
dropsy, gourmands, hypertrophy of the roots, cellular rottenness,
frondescence, phyllodia or chloranthia, asphyxia of the seeds and
roots, putridity of the seedlings.

Use. — Water serves as a solvent or vehicle for most of the agents
used to combat plant diseases ; but it can by itself alone serve as an
insecticide in many cases, and as it is cheap it is profitable to use it.
Cold or hot water is used as follows, accoi'ding to circumstances :
Cold water : Submersion ; spraying. Hot icater : Immersion ; spraying.

(a) Cold Water," Submersion. — Submersion or artificial inunda-
tion asphyxiates the insects living or refuging in the soil. It consists in
placing the area of the ground to be treated under water for a period
of from two to sixty days, according to the nature of the soil and the
kind of parasites to be destroyed. The soil must only be slightly per-
meable, the ground must not be on a slope, and it must be near a source
of water capable of furnishing 6000-30,000 cubic metres per hectare (24
acres), and to maintain it at that for a certain time. Submersion is not
efficient unless it be complete, so that it may soak deeply into the
inundated ground and be executed under certain conditions. The
submersion of fields and vineyards is in use in different countries of
the globe, and everywhere gives encouraging results. The costs of
submersion are not great when near a river from which the water can
be led ; the expense in that case only amounts to 41 francs per hectare,
say 13s. per acre. But when the water has to be brought by elevating
machines then it may amount to 200 francs (£8) per hectare, say €'3 4s.
per acre. To this amount must be added the co=t of manuring,

24 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

which must be abundant as the immersion exhausts the soil. Sub-
mersion was recommended for the first time in France in 1864 for the
destruction of insects in meadows and fields. In 1870 the same treat-
ment was applied to vineyards attacked by the phylloxera, and lately
it has been used to render forests wholesome.

Submersion of Fields and Meadows. — The inundation of
meadows and fields destroys the larvas of Coleoptera (beetles, weevils,
etc.) and the grubs of the Lepidoptera, of which the following are the
most important : (1) Melolontha vulgaris (white worm), larvae of the
may-bug (cockchafer). — Artificial inundations have been in general use
in Hungary since 1888 to destroy this larva. The meadows are sub-
mersed for eight days, and after that time all the white worms have
disappeared. De la Blanchere has, however, seen water remain
more than a month on ground infested with white worms without
these being destroyed. That is explained by the fact that the larva
of the cockchafer, very sensitive to moisture, to avoid contact there-
with buries itself at such a depth as protects it from inundations.
But it is only in impermeable ground that the white worm has the
time to withdraw itself from the action of water. In such ground
recourse should not be made to artificial inundation but to carbon
disulphide. During the two years of its evolution, the white worm
descends into the soil in October, to a depth of about 2 feet, so
as to pass the winter, beyond the reach of cold, and it is only in
spring that it ascends to the level of the roots to gnaw at them. Ac-
cording to the habits of this insect it is, therefore, in spring and in'
summer that the ground should be flooded. (2) Phytonomus punc-
tatus, Fb. — The larvae of this weevil are destroyed by flooding almost
at the very outset. In America the cotton plantations are flooded to
destroy the numerous parasites in the soil. (3) Agrotis segetum,
W.V. (grey worm grub of the dart moth). — Flooding to destroy
this insect ought always to take place in summer. In many cases
flooding of the fields by the excess of moisture exerts a vexing effect
on plants by retarding the ripening of the crops, or by developing
adventitious plants or parasitic fungi. It is not so, however, with
all crops, and it has been observed that submerged beets have more
vigour and resist the fungi which ravage them better during drought,
such as the Phonia tahifica, the disease of the petiole of the leaves, the
Pleospora j)idrefaciens or the heart rot, and the bacillus of the bacillary
gummosis of vine. These diseases being less intense after submersion
the method is advantageous.

Submersion of Forests. — Anderlind has shown the great service
which the submersion of forests can render in the destruction of the"
insect ravagers of woods, the larvae of which find a shelter under the
moss and humus surrounding the stocks. In the different countries
where submersion is in use the most dangerous insects only occasion
insignificant damage, it is therefore one of the most powerful preven-
tive measures against great invasions of certain forest parasites. The
following insects are destroyed by submersion : MelolontJia vulgaris, L.
(common cockchafer). Weevils injurious to conifers : Ilj/lobivs Abistis,
L. (lai-ge spruce fir weevil). The Scolytides so injurious to deciduous

*

SUBMERSION OF FIELD AND FOREST. 25

trees : Hylesinus ater, F. ; H. ojmcus, Er. ; H. augustatus, Hb. ; H.
cunicularius, Kn. The saicflies, very injurious to coniferae, because their
larvae not only attack the adult needles but prefer to devour the young
shoots : Lyda campestris, L., and L. pratensis, L., the larvae of which
bury themselves in August in the moss at the foot of trees to pass the
winter there. L. erijthrocephala, L. (red-headed Lyda), the larvae of
which hide at the foot of trees in the month of June. Lophyrus Pini,
the larvae of the second generation metamorphose into grubs in the
humus of the forest after passing the winter there. Gryllotaljm
vulgaris, Latr. (mole cricket). Winter submersion has little action
on it, because like the white worm it descends deeply into the ground
at the approach of cold. The following Lepidoptera : Lasiocampiia
Pini (or bombj^x of the pine), the grub of which hibernates as chrysalis
in moss at foot of tree. Trachea piniperda and Fidonia jnniari, L.,
both hibernating in ground in the state of chrysalis. Submersion also
frees the forest from the rodents which undermine it, and which in
winter nibble the bai'k of young trees. But if on the plain the
difficulties of submersion are not great, on the slopes where it is
necessary to trace a series of parallel channels which flood the ground,
by overflowing, this method becomes very costly, especially if it is
necessary to raise the water by means of turbines or pumps.

Antiphylloxeric Submersion. — In the beginning of the phyllo-
xeric invasion in 1868, the sands of the dunes (sandhills) were found to
be unfavourable to the propagation of this dangerous homoptera. The
fact was observed at Aigues-Mortes, where vines planted in the dunes
remained flourishing, whilst those planted in the neighbourhood died
without exception. According to Foex the sands exhibited a certain
immunity to the phylloxera when they contained at least 80 per cent
of silica, but a small amount of clay or limestone sufficed to deprive
the soil of this precious property. This immunity, studied by Van-
nuccin at the viticulture laboratory of Montpellier, would appear to
be due to the asphyxia produced by the water retained by capillarity
between the grains of sand. Is that water sufficient to cause the
asphj'xia of the insect ; is it not rather the physical constitution of
the sand which hinders the passage of this insect from one stock to
another? That is a point which has not yet been proven. Balbiani
disputes the theorj- of the asphyxiant action of water in permeable
ground consisting almost exclusively of silica ; he has in fact caused
young phylloxera which he had hatched in a sand medium to live
under water for fifteen days. On the other hand, Faucon has observed
that it takes forty-five daj's' immersion in water to kill the phylloxera.
Now, sands are never impregnated so long by rain-water. Be that
as it ma}', it was this immunity of the sands which gave the idea of
submersion for the destruction of the phylloxera. It had formerly
been remarked that long-continued rain was unfavourable to it, and
that it shunned moisture by burying itself in the soil at great depths,
only dying when the soil was thoroughly soaked. Eminent vine-
growers, Faucon and P. Castelnau, concluded that submersion might
be efficient, and since 1870 have submitted a part of their vines to
this treatment. The results obtained were surprising. The following

26

INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

table prepared by Faucon gives an idea of the improvement in the
crop by the submersion of the vine : —

TABLE I. — Showing the Effect of the Systematic Immersion of Vineyards on the
Volume of Wine Produced.

Year.

1867
1868

1869

1870
1871

1872
1873
1874
1875

Refnarks.

Year before the phylloxera invasion

First year of invasion vines fumigated, non-sub

merged .......

Second year of invasion vines fumigated, non-sub

merged .......

First year with submersion without manure .

Second „ ,, ,,

Third year with submersion and manure

Fourth ,, ,, „ (frost)

Fifth

Sixth

Wi?ie in

Wine in

hectolitres.

gallons.

925

20,350

40

880

35

770

1-iO

2,640

450

9,900

849

18,678

736

16,192

1135

24,970

2680

58,960

Henceforth submersion was not slow in finding numerous partisans.
It has been practised a little all through France, and its use has ex-
tended to abroad. At the present time its efficacy is entirely accepted,
and also the manner in which it is necessary to operate without injur-
ing the submerged plants. In many districts the vines have been
saved from complete destruction, and in other districts, formerly un-
cultivated, productive and flourishing vineyards have been created.
Camargue is an example. In this district, where, however, the inun-
dation water is charged with salt, submersion presents special difficul-
ties, and good outfalls must be organized if it is wished to avoid seeing
the salt appear at great distances.

Submersion in Actual Practice. — To submerge certain privileged
vineyards the water of a neighbouring river may be deflected in part
and brought on to the land by a natural slope. In countries where
water is scarce it has to be propelled on to the land by powerful cen-
trifugal pumps working day and night. In all cases of winter
submersion the vineyard is divided into compartments of 4-6
hectares (10- lo acres), separated from each other by small dams
and communicatory through small ditches. Before running on the
water, care must be taken that the surface is well levelled so that the
water spreads regularly. In very windy districts, such as Vaucluse
and I'Aude, Barral advises the vineyard being divided into more
numerous compartments, the divisions between which serve to break
the waves raised by the wind before they attain too great an amplitude.
Duponchel, an advocate of underground irrigation, advises, in execut-
ing the latter, to excavate around each stock so as to lay bai-e the roots
of the tree, thus forming as many closed basins which communicate
with each other by small channels. Water is made to flow therein
and is imbibed to a gieat depth by the soil around the stocks. When
the ground is siifliciently wet and all the water has been absorbed, all

SUBMERSION OF VINEYARDS.

27

that has to be done is to fill in the excavation with the dry soil placed
on one side, to spread it and rake it. Submersion is performed either
in winter or during the active period of the vegetation of the vine.

A. Winter Submersion. — Winter submersion is a process which
cannot evidently be applied everywhere, and which i^equires special
conditions, of which the following are the principal : (1) The ground
must be slightly permeable, or very permeable but with an imper-
meable subsoil, such as is met with in the low plains of the French
coast, and in isolated spots in the river alluvial soils of some of
the chief water- courses. It is evident that too great a permeability
of soil would require too large a volume of water. The daily decrease
in the level of the water should not exceed a maximum of 10 centi-
metres (4 inches), a centimetre in depth corresponding to 100 cubic
metres of water per hectare, say 1404 cubic feet per acre. (2) The
ground ought to be perceptibly flat or very slightly inclined, a slope of
3 centimetres per metre (3 in 100) rendering submersion impracticable.
(3) The vineyard should be situated, if possible, near to a stream of
water, to an abundant spring, or to an artesian well, for it requires at
least 6000 cubic metres of water per hectare, 84,780 cubic feet per
acre. During the duration of the submersion, there is a daily loss
of water, not only from absorption by the soil but also from evapora-
tion into the atmosphere. The amount of water absorbed daily and
the duration of the submersion have been studied by Chauzit and
L. Tronchaud-Verdier, who have prepared the following table : —

TABLE II.

-Showing the Daily Loss of Water by Absorption by Variotis Soils
during Submersion.

Soil.

Duration of

Autumn.

Submersion.
Winter.

Daily Loss of Water.

Slightly permeable
Fairly „
1 ermeable ....
Very permeable .

50-55 days
55-60 „
65-70 „
90

55-60 days
60-65 „
70-75 „
90 „

1 centimetre
1 to 4 centimetres
4 to 7
8 to 9

Evaporation into the atmosphere averages 6 millimetres in twenty-
four hours in winter, though it reaches 10 millimetres in summer.
(That is at the rate of an output of 1 litre per second per hectare, which
is calculated in general as the general output of the channels serving to
irrigate meadows.) (4) The duration and efficiency of the submersion,
moreover, depends on the climate. It is known that in France it can
only be practised in the centre and south. In the north the vines
would have to pass the winter surrounded by ice, which would
seriously injure them. The duration of the submersion should
average sixty days in south and thirty days in central France.

B. Submersion During the Active Period of the Vine. — Where
large quantities of water are deficient, summer irrigations, recom-

28 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

mended by Duponchel, Chauzit, and Dr. Debray, may be adopted.
Deb ray has, in fact, remarked that the phylloxera is killed more easily
during the active period of the vine, and that the dm-ation of the submer-
sion can be reduced to eight days in September, while fifteen to twenty
days are required in October, and forty to sixty days in winter. In
this connexion the underground irrigation described by Duponchel
produces the best effect. So that submersion may be complete and
efficacious, i.e. so that the water can penetrate 2 feet into the soil, it
requires 1000-1200 cubic metres of water per hectare, say 250-300 litres
(55-66 gallons) of water per stock. It is executed during dry periods,
when vegetation is not very active. It has been found, on the other
hand, that short, rapeated irrigations lasting forty-eight hours in
summer, especially if underground, are as injurious to the phjdloxera
ag long winter irrigations. Whilst even three days' immersion in
cold districts are injurious, underground irrigations of forty-eight
hours in the dry regions of the South have a favourable action on the
development of this plant. The causes, which in the exceptional con-
ditions of the French climate insure the prosperity of the vine and
the quality of French wines, are none other than the climate itself and
the method of culture applied, the hoeing of the soil. It creates on
the surface of the soil a shallow layer of friable earth, which by break-
ing the continuity of the capillaries arrests all evaporation from
below. The rain-water thus imprisoned in the soil without com-
munication with the exterior air constitutes that lasting store of
underground moisture, which can only be evaporated by the plant
which aspirates it by the roots and which loses it by the leaves. The
sap thus elaborated acquires that peculiar property of being specially
apt to develop fruits, whilst in moist districts submerged too often
the more aqueous sap perfectly produces herbaceous vegetation and
yields few grapes. To produce grapes of superior quality the fruits
must be developed in a warm medium, and the roots be in a moist
and warm medium. These essential conditions are awanting when
prolonged superficial submersion is practised, but are not greatly
affected by the underground irrigations recommended by Duponchel.
Superficial sprinkling of the soil never gives useful results as regards
grapes, but develops branches full of leaves {pampres). The super-
ficial evaporation of the water so sprinkled by cooling the soil must
retard the ripening of the crop. Submersions would therefore in
general be rather prejuiicial to the quality of the crop of a healthy
vine. As a curative agent, they produce, on the other hand, two
effects equally advantageous, they enable the vine to reconstitute its
radicular apparatus (root hairs) more or less atrophied by the gnawing
of this lous3. From this point of view, the irrigation of the vines
may be regarded as of practical utility, but it should be executed
with the greatest of precaution so as to modify as little as possible
the special conditions which insure the quality of the grape. A
sufficient imbibition must be created to be injurious to the phyl-
loxera, and favourable to the development of root filaments, avoiding
all loss of heat by superficial evaporation. These conditions are
realized by underground irrigation, especially if it be accompanied by

SUBMEESION OF VINEYAEDS. 29

the addition of nitrogenous manures. In spite of the good results
obtained by submersion and underground irrigation, these can only
be regarded as a palliative and not as a curative method. Long
winter submersions, short summer irrigations, do not kill all the
phylloxeras which ravage the roots, and a new invasion always occurs ;
thus the treatment should be annual. To diminish the number of
the insects and stimulate the vegetative energy of the plant is not a
sufficient remedy, and to re-establish the health of the plant it is well
to destroy the parasites by powerful insecticides, such as carbon di-
sulphide and sulphocarbonates, at the same time as the radicular
system of the vine is strengthened by subterranean irrigations. Simple
submersion along with strong manuring, by stimulating growth by
moisture and fertilizers perceptibly diminishes the action of the phyl-
loxera ; but it only creates, in reality, a modus vivendi between the
parasite and the plant. In these conditions the latter may produce
abundant growth of leaf, but it will only give in the majoiity of cases a
mediocre grape. It follows from the interesting researches of Maquenne
and Deherain, that when a soil is withdrawn from the action of
oxygen, as happens when it is covered by a sheet of water, the nitrates
which it contains disappear rapidly, owing to the action of certain
reducing ferments. On the other hand, Muntz has tried to find out
how the roots of vines immersed for two months can respire. This
long privation of air ought to be injurious. To prove it, Deherain
and Vesque submitted vines for fifteen days to immersion in distilled
water, and found that they rapidly died, whilst others placed in
aerated water were in perfect health. It is, therefore, the want of
oxygen which in submersion may well prove fatal to vines, and that
more readily when it is practised during the period of activity of the
sap. Eiver water used for submersion is the best, because it always
contains air and nitrates, and vines submerged in these conditions
resist for two months at least. That is an established fact which it
is interesting to explain. The above-named scientific observers
believe that the nitrates reduced by the ferments are converted into
laughing gas which contains oxygen, and may support the respiration
of the roots. This reduction observed in submerged land may become
useful to vegetation, as it prevents the asphyxia of the vine. It is
thus necessary to spread on the land an appreciable amount of
nitrate if it be desired that the submersion should not injure the vine.
French vine growers use in fact 600 kilogrammes of nitrate per hectare
(528 lb. per acre), which is in no way exaggerated, but appreciably
increases the cost of immersion. Certain muddy waters, such as
those of the Dordogne and Garonne, for example, enable the amount
of manure to be reduced a little. However, in spite of all the care
brought to bear on immersion, there are vines which do not support
the treatment. Espitalier cites the following species which die very
rapidly : La Carignac, le Grenache, le Mourvedre, la Clairette, le
Malbec, le Merlot, and in general all the valuable species, whilst the
Cabernet, the Petit Bouschet, and I'Aramon accommodate themselves
well to it. This explains why simple immersion has been replaced in
large vine-growing countries like the Gironde by irrigations with

30

INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

sulphocarbonate. Another drawback of submersion is that the vines
planted in low grounds are attacked by all the cryptogamic parasites
which multiply in moist districts and suffer more therefrom than
anywhere else.

Moreover, the following, according to Tisserand, is the increase
in the use of immersion and of insecticides in the treatment of the

vine

:-^4

TABLE III. — Showing the Increase in Area of the Sub))iersion atid Insecticidal
Treatment of Vines in France.

Year.

Stibmersion.

Carbon
Disulphide.

Potassium
Sulphocarbonate.

Hectares.

Hectares.

Hectares^

1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890

8,093
8,195
12,543
17,792
23,303
24,339
24,500

33,455
30,336
32,738

5,547
15,933
17,121
23,926
33,446
40,585
47,215

66,705

57,887
62,208

1472
2809
3033
3097
6286
5227
4459

8089
8841
9377 .

To sum up, submersion, if of undeniable efficacy, is a barbarous pro-
cess, with many drawbacks, which should be advantageously replaced
by irrigations with sulphocarbonate or with carbon disulphide.
Amongst the antiphylloxeric treatments we should advise, according
to circumstances, the following choice : Annual submersion may be
applied where exceptional conditions combine, accompanying it,
however, by very abundant manuring. Irrigations with sulpho-
carbonate and carbon disulphide are reserved for de luxe vineyards,
such as those of Bordelais, Burgundy, and Champagne. Carbon
disulphide, applied by means of the Pal injector, to be adopted pre-
ferably in small and medium cultures, and especially where the want
of water rendfirs submersion too costly.

Spraying. — Spraying with cold water destroys the following
parasites : Capnodium {Fumagine or smut of fruit trees). — Sorauer re-
commends playing a jet of cold water on the crown of the trees after
pruning that part. However, this operation must be repeated every
evening in summer. Capnodium salicinum, Mntgn. (hop black), may
be prevented by spraying the leaves with cold water and repeating
the process several days (Niajels). Tingis Pyri, Fb. — The pear tiger-
beetle is fought against in the same way by spraying night and morn-
ing under the attacked leaves with cold water, or with a little soap

^ A heotare is 2^ aores approximately. — Tu.

ACTION OF DEY AND MOIST HEAT ON SEEDS AND SPORES. 81

added (Montillot). Tetranychus telarius, L. (red spider), which forms
on different plants a disease called " la Grise," is veiy sensitive to
moisture and does not stand repeated cold-water spraying long
(Thomas). Bryobia rihis (gooseberry acarus) may be fought against'
by frequent sprinkling of the leaves. Spraying with water can thus
be used as a preventive against different species of Fumagine or smut
{Gajinodium), as a means of killing acari, of which the Tetranychus
(red spider) is the most widespread and injurious.

(b) Hot Water acts very energetically on insects and fungi, which
die in contact with boiling water. Plants and their seeds generally
stand heat better. That enables their parasites to be destroj'ed with-
out injuring themselves.

Resistance of Insects to Heat. — All insects in seed are destroyed
below 100° C. (212° F.). Bruchidege (small weevils, pea-weevils) die
in five minutes at 60^ C. (140° F.). Ordinary weevils do not stand
50° C. (122° F.). Grubs touched by water of 50°-80° C. (122°-176^^ F.)
die without exception. Coleoptera (beetles) which sometimes stand
great heat never bear 100° C. (212° F.) (Schribaux, Bussard, and
Etienne).

Resistance of Seed to Heat. — Seeds can undergo a dry heat
without injury, whilst the action of moist heat, and of water above 60"
C. (140° F.) is often injurious. Seed-corn, with the exception of maize,
can support a heat of 100° C. for an hour without its germination
being affected. In spite of the considerable loss in water which the
grain undergoes in such conditions, seed-wheat, for example, which
contained 13 per cent of water before being heated lost 9'4 of water
during the operation. Their vitality is not diminished. Of Japhet seed-
wheat heated for an hour in a stove at 105° C. (221° F.) 97 per cent
still germinated; at 115° C. (239° F.) 95 per cent; at 116° C. (240-8°
F.) 93 per cent ; at 120° C. (248° F.) 56 per cent ; at 125° C. (257° F.)
4 per cent. [Potatoes dipped in boiling water do not germinate.]

During researches on the Alucite Doyere likewise succeeded in
heating seed-wheat dried in vacuo to 100° C. (212° F.) without it
losing its faculty of germinating. By previously drying seeds at a low
temperature Jodin heated grains of seed- wheat to high temperatures
without alteration. Peas and garden-cress seed heated directly to 98°
C. (96-4 F.) for ten hours were no longer capable of germination, whilst
others submitted to the same heat for the same time stood the heat
perfectly, after being heated for twenty-four hours to 60° C. (140° F.).
The peas retained a germinating capacity of 60 per cent. Therefore, if
seed be heated in such a way as to allow the water to evaporate pre-
viously, by heating in an open vessel or in presence of such substances
as sulphuric acid, calcium chloride, and quicklime, they undergo no
alteration. Seed-peas under such conditions stood heating for 206
days at 40° C. (104° F.).

Resistance of Fungi to Heat. — Fungi spores are generally re-
markably sensitive to moist heat, but per contra they stand dry heat
well. Schindler found that the spores of the Ustilaginea which re-
sist very great dry heats, are rapidly injured if the hot medium is
saturated with water vapour. In these conditions the spores of black

32

INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

rust perish at 60° C. (140° F.), those of brown rust at 45°-o0° C. (113°-
122° F.). Herzberg has compared the resistance of spores of different
ages to the action of heat, and found the following temperatures as
those at which they succumbed : —

TABLE IV. — Showing the Temperattires at tchich the Spores of different Species
of Ustilago are Killed.

U. Jensenii.

U. Avence.

U. Perennans.

U.Hordei. U. Tritici.

Old spores .
Young spores

°C.

47 -50 J
50-53

°C.

45i-47i
50|-53i

°C.

40^-42
47^-50^

°C.

43J-45
45^-471

46-47*
45i-47|

It follows that the young spores are more resistant than the old
ones, and that the temperature required to destroy the vitality of a
spore is not the same for spores of different species.

Use. — The sensitiveness of parasites to hot water and the com-
parative resistance of plants have permitted the use of different treat-
ments, especially preventive, to free plants from certain diseases.

Immersion or Steeping. — This consists in dipping seeds or
plants in hot water to free them from disease germs adhering to their
surface.

Hot Water Steeping of Seed-Corn to Kill Disease Spores. — Steeping
seed-corn in hot water is practised before sowing to destroy the
dormant spores of smut and bunt, which adhere to their surface
and help to propagate these diseases. Brefeld, observing that cold
water was injurious to the development of the spores of bunt,
tried washing seed with cold water, and so obtained an appreci-
able but incomplete result. On the other hand, hot water has
been recognized as deadly to the spores of these fungi, and treating
the seed by hot water would wholly suppress cryptogamic diseases if
the seed formed the sole factor of their propagation. To get satis-
factory results steeping the seeds in hot water should be done in a
strictly scientific manner. It is only efficacious if the temperature of
the bath has been rigorously maintained at a certain degree. A greater
heat than that required to kill the spores should be avoided, for it will
appreciably diminish the germiuative capacity of the seed, and may
even destroy it. If there be a difference of sensitiveness between the
seeds and the spores as regards heat, it is so small that a difference
of a few degrees may be fatal. A low temperature should also be
avoided, as it favours the disease instead of preventing it. Warm
moisture helps, in fact, a premature development of the spores. The
promycelium and the sporidia formed then attack the young plant as
soon as hatched. It is a known fact that bunt as well as smut
are more injurious to the plant the younger they attack it. When
well done, steeping in hot water imparts to the seed in many cases a

' To bring to Fahrenheit, multiply by 9, divide by 5, and add 32.

HOT WATER STEEPING OF SEED-CORN. 33

greater germinative capacity, so that the phxnt has acquired a certain
development when the spores which have escaped the treatment
germinate. That is one reason in favour of steeping ; the other methods
of treating seed general!}' retard their germination. Steeping gave in
certain cases results which it had been impossible to obtain by sulphat-
ing (Kuhn's), and it is in such particular cases that its use is prescribed,
in spite of the difficulties of carrying it out which the farmer has to
face in a peculiarly complicated plant, and the minute practical care
required to secure a good result. B. Prevost was the first to observe
that steeping seed-corn in hot water diminished the power of contagion
of smut. In 1888 Jensen studied this treatment with great care
and perseverance. The researches of Kuhn and Sorauer in Germany,
J. Eriksson in Sweden, Linhart and Mezey in Hungary, Kellermann
and Swingle in America, Prillieux and Schribaux in France, confirmed
Jensen's very precise observations and conclusions. The follow-
ing, according to Eriksson, is the manner in which Jensen's method
should be applied on the large scale. The operation requires (1) A
boiler or large pot in which to boil water. (2) Three tubs : No. 1 for
hot water, No. 2 for tepid water, No. 3 for cold water. (3) Two
willow baskets, completely lined inside, including the lid, with bolting
cloth. (4) A thermometer. After having prepared a certain amount
of boiling water, 50 litres (11 gallons) are withdrawn and run into the
first tub, which is cooled to the desired temperature with 40-50 litres
(9-11 gallons) of cold water. In the second tub about 20 litres (4-4
gallons) of boiling water are mixed with 80 litres (17'6 gallons) of cold
water so as to get a temperature between 25° or 30° C. (57°-86° F.).
Cold water is run into the third tub. The seed to be treated is placed in
baskets, the lids of which are carefully closed so as to enable them to be
completely immersed. Each basket contains about half a bushel of seed.
After firmly attaching the basket to a stick it is plunged, first in the
cold water to moisten the grain completely, then the same operation
is repeated in the tepid water, taking care to raise up the basket .and
re-dip it several times. Finally it is dipped for five minutes in the
hot water, raising and lowering the basket. The operation is finished,
and the grains so treated can be immediately sown by hand, or they
may well be spread out to dry. It goes without saying that it is neces-
sary to disinfect the boards on which the grain is spread perfectly, as
well as the bags to contain it, by hot water, bouillie bordelaise, or simply
a solution of sulphate of iron. With three men and two baskets 400-
500 litres (11-13| bushels) of grain may be disinfected in an hour, at
the expense of 25 centimes per hectolitre, or about Id. a bushel.
Kellermann and Swmgle have simplified this process by dispensing with
one of the three tubs, the cold water one. They only use a tub of water
at 43°-54° C. (109-4°-129-2° F.) and a tub of water at 56° C. (132-8° F.).
They use a basket of wire gauze of a capacity of 36 litres, say 8 gallons,
which they only half fill with grain or simply a canvas bag. They
first dip the basket for a minute in tepid water to warm the grain,
then fifteen minutes in hot water at 56° C. They consider it useless
alternately to raise and lower the basket into hot water. Each cereal
is attacked by one or several species of rust, and it is necessary to

3

34 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

examine the action of Jensen's treatment on each of its parasites,
Ustilago Hordei, Bref., on barley (Hordeum vulgare) and Ustilago
Jensenii, Eost., on barley (Hordeum distichum). The steeping of
grains of barley exhibits certain difficulties when these are still sur-
rounded with glumes. By ordinary steeping, the spores between the
gi'ains and the glumes are not killed even if the water is raised to 60°
C. (140° F.), whilst in an atmosphere containing the vapour of water,
Jensen has observed destruction to be complete at 524^° C. (1264" F.).
Eriksson got excellent results by softening them for four hours in cold
water before steeping, and allowing them to swell for four hours in an
aerated place, afterwards bagging them up. It suffices, therefore, to
immerse the grain for five minutes at 52-5° C. (1264^° F., Jensen), at
which heat aU the spores perish. The water can, withotit fear of
diminishing the germinative capacity of the seed, be heated up to 60°
C. (140° F.), barley standing that heat without injury. According to
Kuhn, it is injurious to leave the grain for twelve hours in cold water
before proceeding to the (hot) steep, but by not exceeding four hours.
Sorauer found that such was in no way injurious to the development
of the seeds. Kellermann, Swingle, and Kirchner dispense entirely
with the first immersion in cold water, and claim to have obtained satis-
factory results by one dip in hot water at 52*5° C. (126-^° F.), even if
the grains be glumed. Kirchner found that after a dip of five minutes
in water of 56° C. (132"8° F.) grains of seed-barley germinated thus : —

TABLE V, — Shoioing Effect of Steeping Seed-Barley in Hot Water on Germin-
ative Capacity.

Germijiated Germinated

after tivo days. after ten days.

Per cent. Per cent.

Treated .... 74-5 98-0

Untreated .... 69 -TS 97-0

Besides the disinfectant action there is thus an evident increase
in the germinative capacity of the seeds. Whilst the I'esearches of
Kellermann, Swingle, Jensen, Linhart and Mezey, Prillieux and
Schribaux confirm this observation, Hollrung is of a contrary opinion.

Ustilago Tritici, Jensen (smut of wheat, Tritimmi Sativum) ; Til-
letia caries, Tul., " stinking smut " or " bunt " of wheat ; Tilletia levis,
Kuhn (loose or flying smut of wheat). — According to Herzberg, the
spores of Ustilago Tritici are destroyed at a temperature of 48° C.
(118'4° F.), and those of Tilletia do not germinate after immei-sion in
water of 55°-56" C. (131°-132-8° F.). By treating w^heat grain by one
immersion of five to fifteen minutes in water of 56° C. (132"8° F.),
Sorauer obtained the following results : —

TABLE VI. — Result of Steeping Seed-Wheat i7i Hot Water diiring different

Periods of Time.

Untreated grain ..... 87 per cent of plants which gave

5-17 per cent of " bunted " ears.
Grain treated five minutes . . .91 per cent of plants which gave

0-2'25 per cent of " bunted " ears.
„ ten minutes . . .87!; per cent of plants which gave

6-157 per cent of " bunted " ears.
,, fifteen minutes . . 87n per cent of plants which gave

0-071 per cent of " bunted " ears.

HOT WATER STEEPING OF SEED-CORN. 35

By treating the grain with O'O per cent of blue vitriol he obtained
S6^ pel' cent of plants. It may therefore be inferred that an immersion
of five minutes suffices, and that it has an advantage over blue vitriol
because it stimulates germination instead of retarding it like the latter.
Klebahn, however, is of opinion that immersion has no advantage over
vitriol steeping, and Kirchner asserts that it diminishes the germinative
power. Selby found that the same result was got by immersion as by
treatment for twenty-four hours with a solution of 0"O per cent of blue
vitriol, 0"2 per cent of formaline, and 0'75 per cent of potassium
sulphide. When wheat is immersed on the large scale against bunt it
is well to dip the grain first in water, skim it, and cast aside all those
grains which float. These are precisely the bunt-infested ones. Those
which lie on the bottom of the water are alone dipped in the hot water.
Ustilago Avenae, Eost. (loose smut of oats, Arena sativa) ; Ustiiago
perennans, Eost. (smut of oats. Arena elatior). — The spores of Udi-
lago Avenae stand air heated to 52° C. (125 '6" F.), but they do not
stand dipping in hot water at 54°-56° C. (i29-2°-132-8° F.) (Sorauer).
Kirchner found that seed-oats treated in that way gave the following
result against untreated : —

TABLE VII. — Slioioincj Effect of Steepuig Seed-Oats in Hot Water on Germin-
ative Capacity.

Germinated

Gerjninatfd

OT two days.

in ten ciay^.

Per cent.

P(r cent.

24-75

P4-.5

6-75

81-7.5

Treated
Untreated .

Treatment on the large scale lowers the percentage of diseased plants:-
to about 0'2-0-7 per cent (Eriksson). According to Kellermann and
Swingle, a fifteen minutes' dip in water at 55*6° C. does not alter the
germinative power of oats, and all authors agree in saying that the-
immersion of seed-oats is better than treatment with blue vitriol, because
it stimulates instead of retards the germination. It is therefore from
this point of view a useful discovery, and Klebahn is of opinion that
this treatment, general for all other cereals, is prescribed for oats.

Urocystes occulta, Eabenh. (smut of the stems of rye). — By im-
mersing seed-rye for five minutes in hot water Kirchner obtained
against untreated grain the following results : —

TABLE VIII. — Shelving Effect of Steeping Seed-Eye in Hot Water oti Germin-
ative Capacity.

Germifiated Germinated

in ttvo days. in ten days.

Per cent. Per cent.

Treated .... 91 95-5

Untreated .... 95-25 98-0

Trials on a large scale by Klebahn did not give better results. The
immersion of seed-rye presents no advantage in this case over treat-
ment with blue vitriol, because it retards germination like the latter.
Ustilago Panici-Miliacei, Wint. (smut of millet). — Treatment with

36 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

blue vitriol or immersion may be employed indifferently, as they both
give the same result. The millet seeds must be left seven and a half
to twelve minutes in water at 55° C. (131° F.).

Ustilago Maydis, Corda (smut of maize). — Nijpels prescribes the
immersion of maize bj^ Jensen's method ; it gives good results.

Ustilago bromivora, Fisch. (smut of brome grass, Bromus arvensis).
— According to Eostrup immersion has also been tried with success
against this disease.

Sphaerella Tuiasnei, Junez (black of cereals, CladosjMrium her-
harimn). — Giltay prevented the development of this disease by
immersion in hot water. Kolpin Kavn prevented it entirely on barley
and oats by Jensen's immersion at 52°-53° C. (125'6°-127"4° F.) for five
minutes, after previously softening the grain for fifteen minutes in
cold water.

Piiccinia (rust of cereals). — The numerous experiments of
Galloway in America to diminish the rust of cereals by dipping the
seed for fifteen minutes into water heated to 56° C. (132"8° F.) have
not given the result anticipated. The treated seed gave as many
•diseased plants as the untreated. That is due to the method of
development of the fungus, which does not appear, in fact, to propagate
itself through the seed. Immersion has also been used to prevent
beet diseases, due to fungi propagated through the seed. These diseases
are Pythium de Baryanuin, Hesse; Bhizoctonia violacea, Tul. (beet
Ehizoctone) ; Phoma tabifica, Pril. et Del, (disease of the petioles of the
leaves) ; Pleospora ■putrefaciens, Frank, (rottenness of the heart).
Jensen's method has given excellent results, and it follows from the
trials made by Hollrung that immersion, instead of injuring the seed,
on the contrary stimulates their germination. Treatment with cold
water greatly increases the germinative capacity of beet seed ; but
it must not be kept ninety days after immersion before sowing,
because the effect gradually disappears. If the seed be sown soon after
immersion an excellent result is obtained with very few diseased
plants. The procedure is as follows : The seed, in a wire-gauze
basket, is immersed for six hours in cold water, left to drain ten to
twelve hours in an airy place, then dipped for five minutes into water
heated to 53-5° C. (128'3° F.), taking care to dip and raise the basket
at regular intervals. Nothing further is required but to pass the seed
into a bath of cold watei', and it may be sown at once, or after
standing for not more than ninety days. Summing up, Jensen's
method sometimes gives results inferior to treatment by blue vitriol,
because it scarcely ever diminishes the germinative capacity of
the seed treated ; it is only really prescribed for the disinfection of
seed-oats, for the results are undoulitedly superior. For all other
cereals blue vitriol, bouillie bordelaise, or potassium sulphide may be
prescribed. The latter process was recommended by Jensen himself
in 1895 (" Ceres " powder) as capable of replacing immersion.

Fmmersion of Seed against Insects. — Phylloxera. — Balbiani's re-
searches on resistance of phylloxera eggs show that non-rooted buds can
be treated preventively by one dip of five to ten minutes in water heated
to 45°-50° C. Experiments renewed in 1887 by G. Couanon, G. Henne-

HOT WATER SPRAYING AGAINST MILDEW. 37

guy, and E. Salomon confirm the results obtained. This method is
currently used to-day. Not only does it cause no prejudice to slips
catching root, but it seems, on the contrary, to facilitate it. And the
importance of this treatment is so much the greater as it follows from
determinations made in Algeria (1885), in Champagne (1890), and in
Lorraine (1894), that new phylloxera hot-beds have no other origin
than plants coming from countries infested with this foi'midable insect.
G. Couanon and J. Michon resumed the same experiments and ex-
tended them to rooted plants which are most frequently used in the
reconstitution of vineyards. Eooted Noah plants, dipped for three,
four, and five minutes in water at 53° C. (127'4° F.) (51° C. at the
exit, 123-8° F.), were planted at the same time as test samples. They
took root completely, as well in the greenhouse as in the open air, and
the vines grew very finely. Dipping in water at 53° C. (127'4° F.)
is thus a practical and economic method for disinfecting vines, rooted
or not, for it kills at the same time both the insects and their eggs.
It has also the advantage over the sulphocarbonate treatment recom-
mended by Mouillefert, that it does not require, like this latter, two to
three hours, and has no injurious action on the plants (Balbiani).
Disinfection by hot water gives very satisfactory results ; the same pro-
cess has been used for other fruit trees intended for sale, and cochineals,
the woolly aphis, and other injurious insects, have been simultane-
ously destroyed. According to Danesi, all fruit trees, the peach excepted,
stand very well being dipped for five to ten minutes into water at
53° C. (127"4° F.). To ensure complete disinfection the whole plants
must be entirely dipped into the water at 53^ C. (127'4° F.), and dried in
the air on a copper grating. They can then be packed in disinfected
moss and despatched.

Britchus Pisi, L. (pea-weevil). — To kill this insect Fletcher recom-
mends the following method : A vessel is taken which is half-filled
with the infested peas, and boiling water poured on until they are
entirely submerged. The vessel is then filled with cold water, and
left to stand for twenty-four hours. The peas which do not suffer from
the treatment and which are entirely freed from the insects they
sheltered can then be sown. De la Bonnefon advises to drop the
peas into water and leave them there for some hours. The peas which
remain at the bottom are put into an oven the temperature of which
is 60° C. (140° F.). After some time they are taken out and then
sown.

Hot Water Spraying. — Spraying plants with hot water has not
only been used to destroy injurious insects, but also to cause certain
fungi to disappear, such as the ErysiphecB or mildews, which crawl on
the surface of the epidermis without ever penetrating into the interior
of the tissues. It is owing to this peculiarity that they can be destroyed
by hot water. The leaves of plants stand without injury sprayings of
77°-85° C. (170-6°-185° F.), whilst at that temperature the mildews
disappear entirely. The roots alone of the plant must be protected,
because they suffer from contact with water at that temperature.
Hot spraying has been used against the follow^ing mildews : Unc inula
Americana, How. (oidium of the vine) ; Sjihaerotheca j^annosn. Lev.

38 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

(mildew of the rose bush) ; S2)haerotkeca Castagnei, Lev. (mildew of
the hop).

Hot water has found numerous applications against insects very
sensitive to heat. Galeriica of the elm ; Formica, ants ; Pierides of
the cabbage ; Cochylis Pyralis of the vine ; Cabbage lice ; Diaspines,
Cochineals, red spider.

Galeruca Cahnariensis (Galeruca of the elm). — To destroy this
insect, Eobert sprays the stock and the lower part of the trees with
boiling water. The time for doing so is selected when the larvae are
being transformed into grubs around the stock, i.e. about the end of
July or beginning of August.

Formica (ants). — Boiling water destroys ants. It may be used
each time that there is no risk of touching the roots, which do not
stand hot water at that temperature.

Pier is [Pierides of the cabbage). — When they are not destroyed
when they are small, the grubs of Pierides (white butterflies) so ravage
cabbage as to render them unsaleable. Eiley has observed that the
grubs die when they are sprayed with water at 55° C. (131° F.), whilst
cabbage leaves do not suffer at that temperature.

Conchylis AmbigneUa, Hubn {Cochylis of vine) ; Tortryx vitana
{Pyralis of vine). — Scalding is the best method of destroying these in-
sects. It consists in spraying the stocks with boiling water when vege-
tation is arrested, and when the insects have chosen the fissures in the
bark as a common refuge. This process, discovered in 1828 by Benoit-
Eaclet, vine grower at Romaneche (Saone et Loire), was not known
until 1838. Raclet experimented on the same vines for ten years,
and after having found all the advantages of scalding, he advised its
use, preferably in Mai'ch or April. According to the researches
published in 1868 by Terrel des Chenes, it has been definitely de-
cided : (1) That scalding, even when applied ten years running, did no
harm. (2) That it not only destroys Pyralis, but also many other
insects of the vine. (3) That it also destroys the vegetable parasites
of the vine, mosses, lichens, etc. (4) That it stops the growth of ad-
ventitious buds along the old wood which is a loss of sap for the
stock and thus saves pruning. However, in spite of the excellent re-
sults, this method is practised very little, and that because it requires
a litre of boiling water per stock, and it is not easy to use such large
quantities in the middle of a field. For some years scalding of vines
has become common by an improvement in the apparatus. The
water is now heated in a portable boiler (fig. 1) fitted with two lugs by
which it can easily be carried. It costs 30-50 francs (24s. -40s.). When
the water boils the workman is warned by a whistle on the safety valve.
He then fills a sort of tinned-iron coffee-pot (fig. 2", holding a litre,
and covered with cloth, or better still with a double jacket, so as to
prevent cooling. The water must be at 80° C. (176° F.) at the time
it touches the stock for the destruction of Pi/ralis, and 90^-100° C.
(194°-212° F.) for Cochylis, so that it may penetrate the silky cocoons
which protect the small grubs. To increase the temperature of the
water carbonate of soda may be added; 5° or 6° C. (9°-10-8^ F.) extra
are tius obtained which makes up for the exterior cooling. In
em|)tying the coffee-pot entirely on each stock the workman must

HOT SPRAYING AGAINST COCHYLIS.

•39

act rapidly. He should with the drawn-out spout of the coffee-pot
pour the hot water on the stock, rising in a spiral from the bottom, so
that the water at the required temperature penetrates into all the
interstices of the bark. The operation must be performed from
below upwards, for if scalding was begun from the top of the stock
the excess of water, perforce cooled, would flow over the lower parts
and fill the interstices ; the boiling water poured afterwards would
have no mortal effect on the insects on the bottom of the stock,
because they would not receive it directly. This precaution is parti-
cularly necessary in treating old vines, because these are generally the
refuge preferred by grubs owing to the rugosity of the stock. Two
workmen suffice to carry out the scalding ; one feeds the fire and fills
the boiler as the boiling water is drawn off, the other runs the hot
water into the coffee-pots and pours their contents on the stocks.
Working thus, 1500-2000 stocks can be treated per day. The boiler

Fig. 2. — Coffee-Pot for Scalding Vines
with Hot Water.

Fig. 1.— Portable Boiler.

consumes about 200 kilogrammes (4 cwt.) of coal per day. To diminish
the labour, large boilers are also used, with taps to which india-rubber
tubing is attached ending in a nozzle, with intermittent jet. This
nozzle which projects the water on the stock has the advantage of
penetrating deeply into the cracks of the bark. This process, though
preferable to others, is only used in large vineyards. Scalding should
be done after the vintage when the grubs have taken refuge in the
bark, and before they have assumed the chrysalis form, for the latter
is not so sensitive as the grub. It is carried out as soon as pruning
is finished and preferably in calm, fine weather. To combat the
Cochylis it is necessary to operate in October or November, whilst the
grub has not yet finished its cocoon ; against the Pyralis, which re-
mains all winter as a grub, proceedings can be taken all winter up
to May before escape from the cocoon. In districts where props are
used these are boiled by placing them in cases, into which steam is
injected for eight to ten minutes, or by steeping them in boiling water

40 INSECTICIDES, FUNGICIDES, AND WEED KILLEKS.

for five minutes. Scalding carefully done with water at the tempera-
ture indicated is always efficacious, and has no injurious action on
the vines if care be taken to perform it before the appearance of the
bud. It is recognized that of all the treatments adopted against the
Pyralis, scalding is still that which succeeds best. But it must be
carried out with a certain regularity each year, otherwise the butter-
fly would again appear. This is the treatment which succeeds best
against the Cochylis, provided it be done from October to November.

Margantia histrionica, Hahn (the red cabbage bug). — Murfeld has
shown that these small bugs do not stand water heated to 6o'5° C.
(150° P.), a heat which does not alter cabbage leaves. Cochineals also
suffer much from treatment with hot water. Eeh found that
generally they did not stand a great heat. Water at 54° C. (129"2° F.)
kills them in forty minutes and water at 55° C. (131° F.) in twenty-
two minutes ; water at 60°-65° C. (140°-149° F.) kills the apple cochineal,
Asjjidiottts ostreaformis, and the pear cochineal, Dias2)is jji^icoki, but
most cochineal stand a greater heat. The scalding of trees in winter
is, therefore, an excellent method of freeing them from all these
parasites.

Tetranychus telarius, L. (red spider). — In November this acarus
takes refuge under the bark of the stock. The hot-water treatment
can then be applied. The scalding executed as described above to
destroy Pyralis can at the same time get rid of the red spider.

2. Hydrogen Peroxide, HoO^. — Prejmration. — By decomposing
barium peroxide by hydrochloric acid in the cold and then precipitat-
ing the baryta by sulphuric acid.

BaO^ + 2HC1 = BaCL, + HoO,

Barium Hydro- Barium Hydrogen

peroxide. chloric chloride. peroxide,
acid.

Pro23erties. — Hydrogen peroxide is a colourless syrupy liquid. A
heat of 27°-30° C. (80-6°-86° F.) and light decompose it into water and
oxygen. Aqueous solutions are very unstable but a small amount of
sulphuric acid gives them stability.

Use. — The numerous applications of hydrogen peroxide in human
medicine led to the expectation of good results in the treatment of
plant diseases with this product. Hitchcock and Carleton tried
hydrogen peroxide in solution of different strengths on the uredo-
spores of Puccinia, but a solution of —

TABLE IX. — Result of Ti-eatincj Puccinia Uredospores with Hydrogen Peroxide
of Various Strengths.

0-1 per cent acting during 7 hours on spores of Puccinia graminis, Pers.
1-0 ,, ,, ,, 17 „ „ Puccinia Rubigo vera, Wint.

ii"0 ,, ,, „ 14 ,, „ Puccinia coronata, Corda.

far from destroying these spores rather favoured their development
than otherwise.

CHAPTEE II.

HYDROGEN SULPHIDE— SULPHUR.

3. Hydrogen Sulphide (Sulphuretted Hydrogen, H.S). — Pre-
paration.— By decomposincr sulphides by a dilute acid. Iron sulphide
is generally used. It is dropped in pieces into a Wolff's flask, two-thirds
filled with water. By running in dilute sulphuric acid through a funnel
there are produced (1) iron sulphate and (2) sulphuretted hydrogen,
which is collected in a gasometer.

Properties. — Hydrogen sulphide is a colourless gas with the odour
and taste of rotten eggs. It burns with a blue flame. It is very
poisonous and treacherous, for it acts without any other warning than
a bad smell. A small bird perished in an atmosphere which contained
yjy ^ith ; a horse does not live long in an atmosphere containing o^o^th
of this gas. Under its influence the globules of blood are unable to
fix oxygen.

Action on Plants. — Hydrogen sulphide is also injurious to plants ;
in its presence the leaves are coloured with yellow spots, which en-
tirely invade them, then the plants die. Schroder and Kerns found
that to be the case in the neighbourhood of factories which disengage
a certain amount through their chimneys ; gasworks amongst others,
for coal gas always contains a certain quantity. An atmosphere
only containing ^^j^th of hydrogen sulphide, that is to say, an amount
scarcely perceptible to the smell, but slightly blackening paper steeped
in lead acetate, is poisonous to the plant. However, the toxic dose
varies greatly with the species of plants. Even roots themselves are
capable of absorbing it, and take a blue colour (Kny).

Action on Insects. — -Mouillefert has examined the action of hydro-
gen sulphide on the phylloxera. "On roots exposed in a flask filled
with this gas these parasites died in three minutes, but whilst at the
end of that time the adults were dead, the larvae and the eggs did not
appear to suffer. In an atmosphere containing 1 volume of H_,S in
150 volumes of air the phylloxeras were found dead after twenty-
four hours. If it contained 1 volume of H^S in 150 volumes of air
it took forty-eight hours to desti'oy these lice completely. Now, as a
litre of sulphuretted hydrogen weighs 1*5 gramme, an atmosphere con-
taining 1 per cent of this gas by volume only contains by weight 0'0015
per cent of that acid. As that amount represents the limit of toxicity
of this gas for the phylloxera, and as it requires 0-0016 gramme of car-
bon disulphide in 100 c.c. of air, it may be concluded that hydrogen
sulphide is as poisonous to insects as carbon disulphide.

(41)

42 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Use. — Phylloxera. — To utilize this property, therefore, of hydrogen
sulphide, it only remains to discover a process capable of giving rise
to the formation of this gas in the layers of soil round an infected
vine. The alkaline sulphocarbonates fulfil this object. They decom-
pose in the presence of moisture and the acidity of the soil into alka-
line carbonate and hydrogen sulphide.

K2CS3 + HoO + CO, = KXOg + CS, -^ H,S

Potassium Water. Carbonic Potassium Carbon Hydrogen
sulpho- acid. carbonate. disul- sulphide,

carbonate. phide.

Mouillefert tried ammonium sulphide, which acts perceptibly on
the phylloxera in the same way as hydrogen sulphide. He buried
around the roots, after having laid them bare, 500 grammes {l^xy ^•)
per stock of a mixture of 36 parts of calcium sulphide and 66
parts of sulphate of ammonia. Under the influence of moisture these
two salts dissolve in the ground, and yield by double decomposition
ammonium sulphide and calcium sulphate. The result was negative.

Melolontha vulgaris (cockchafer). — The insecticide property of
hydrogen sulphide has been utilized to destroy numerous injurious
insects, living in the soil, especially the ivhite loorm. Dr. Precht has
taken out a German patent to claim a process of formation of this gas
in the soil. Prior thereto Roy had recommended the burying in the
ground of cinders rich in iron sulphide. In Italy good results are
obtained against the white worm by ploughing in white mustard, more
especially mixed with oae ton of gypsum per acre. The decomposition
of these plants would appear to produce much sulphuretted hydrogen.

Heterodera Schachtii, Schm. — The ploughing in of crucifers and
gypsum did not give the result expected. ■

Cochineals — Co ]uillet did not succeed in destroying the cochineal
of the lemon by covering this tree with an awning, and disengaging
sulphuretted hydrogen under this improvised " cloche ".^

4. Sulphur, S. — Sulphur, in combination with metals and metal-
loids, is very widely distributed in nature. It is chiefly met with as
sulphides of iron, copper, lead, mercury, zinc, antimony, and arsenic.
Native it is found in lacustrine deposits associated with marl, and
especially in the precincts of volcanoes as a product derived from
volcanic emanations. It is found in the mines of Vesuvius of Lateria,
near Rome, in those of Etna and Stromboli.

Preparation. — When sulphur forms 50 per cent of the mass in
which it is incorporated, it is fused in cast-iron pots at a heat not ex-
ceeding 140" C. (284° F.). The fused sulphur flows into horizontal
retorts — exposed to the direct heat of a furnace — in which it is brought
to the boil and the vapours conveyed into a large masonry chamber,

' Note bji Transla'nr. — But it must not be forgotten that sulphuretted hydrogen
is heavier than atmospheric air in the proportion of 87 to .^1, that is, 100 cubic
inches of the former weigh 87 grains, and of the latter SI grains. This difference
in density must retard diffusion, so that the bottom of the plant would get an undue
shar and the top less than its share. Instead therefore of placing the generating
vessel on the ground it should be at least well up the tr.e.

PREPARATION OF SULPHUR. 43

in which flowers of sulphur are first collected before the chamber
becomes heated. The sulphur which follows comes in contact with
the more hot sides, and when these have reached a temperature of
110^ C. (236^ F.) it coadenses in the liquid state and runs into wooden
moulds through an opening for the purpose. Brimstone is so ob-
tained. For agricultural purposes sulphur is prepared under different
forms: (1) Sublimed sulphur, or Flozvers of sulphur, is an extremely
fine powder of a yellow straw colour, which, examined under the
microscope, appears as small rounded grains, studded with small
points. It often contains sulphurous acid and sulphuric acid in the
proportion of 1 per cent. (2) Ground sulphur is obtained h\ the
pulverization, grinding, and sifting of brimstone. Ground sulphur
can now be obtained, the fineness of which almost equals flowers of
sulphur. It has the advantage of being neutral and cheaper. It con-
sists of angular gi-ains, and is paler than sublimed sulphur. (3) Wind-
hloivn sulphur is of a bright colour, absolutely neutral, and can be
passed through a 100 sieve, which proves that it is almost as fine as pre-
cipitated sulphur. It shows branching particles under the microscope
and grains of regular dimensions. Like ground sulphur, it neither
contains sulphm-ous nor sulphuric acid. It is dearer than gi'ound
sulphur. (4) Precipitated sulphur is impalpable. It is extracted
from the spent material used for gas purification ; when it is imperfectly
purified it still contains tar, c^'anides, and, as it is somewhat hygi'o-
metric, it burns the leaves. Hence its restricted use in the sulphuring
of plants. It is obtained, also, by a chemical method : alkaline poly-
sulphides, treated by hydrochloric acid in aqueous solution, give off
hydrogen sulphide, and deposit at the same time a precipitate of almost
white sulphur. This precipitated sulphur is dearer than the foregoing ;
it contains sulphuretted hydrogen and alkaline sulphides. (5) Mix-
tures containing sulphur. — In nature sulphur often occurs mixed with
gypsum, carbonate of lime, sand, in proportions varying from 5 to 40
per cent. Such minerals are ground finely and marketed as Apt sul-
phur and Briabaux sulphur. The " Minerale Greggio " extracted in
Sicily is an earth containing 40 per cent of sulphur, 2 per cent of
alkaline carbonate, 11-8 per cent of carbonate of lime, 42 per cent of
maguesia, 36 per cent of sulphate of lime, a little iron, clay, and
arsenic. The value of these mixtures depend on their sulphur con-
tent; the gypsum and carbonate of lime have no anticryptogamic
property. In many cases they are preferred, and that is what has
contributed to the preparation of artificial mixtures containing 10-
50 per cent of sulphur only. The Fonta powder, used since 1857,
contains 10 per cent of sulphur and 90 per cent of talc. A marble
worker of Saint-Beat, having tried a mixture of 50 per cent of ground
marble, and 50 per cent of sulphur, found that this very efficient
treatment occasioned no scorching on the vine, even during great heat.
Neutral mixtures have, therefore, been prepared for this purpose, con-
taining 50 per cent of sulphur and 50 per cent of gypsum, carbonate
of lime, or clay. Now that cryptogamic diseases, like mildew and
black rot, have invaded the vine already attacked by oidium, attempts
have been made to reduce the multiplicity of treatments by mixing

44 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

sulphur with cupric powders. These powders, such as " Cupro-Calcite,"
will be dealt with when treating on oidium and mildew.

Use. — The use of sulphur goes back to 1846. It was by rule of
thumb that the remedy was first discovered by the gardener Kyle,
in experimenting in the greenhouses of Lyton with mixtures of sulphur
and lime. At that time sulphur was already known as capable of
curing mildew, and some gardeners used it. But when, in 1848, the
oidium appeared, destroying the crops in the neighbourhood of Paris,
J. B. Dumas, the Minister of Agriculture, ordered the disease known
as Oidium Tuckeri to be examined, and the different remedies recom-
mended to combat it to be tested. It ■was thus that Duchartre, Professor
of Botany at the new Agronomical Institute of Versailles, aided by
Hardy, the gardener of the palace, undertook the study of the action
of sulphur, and that he decided it to be efficient against the oidium.
Gouthier, horticulturist at Montrouge, constructed at this time a bellows
for sulphuring, which contributed much to spread the use of sulphur
around Paris. Henceforth, owing to this use of sulphur it was pos-
sible to contend against the oidium, and in 1852 and 1853 the vines
of Chasselas and Thommery were entirely preserved. Sceptical vine-
growers, persuaded that the oidium could only develop on perishing
vines, sought at the same time a remedy by improving the culture.
The good results obtained in 1852, 1853, and 1854, by Lafforgue, Eose,
Charmaux, Eendu, and Mares, were disputed by Cazalis AUut, who,
after six sulphurings, executed on 140 hectares (350 acres), did not sup-
press the oidium. There were long gropings in the dark, unsuccessful
years, nevertheless, owing to the persevering efforts and profound
study of Mares, a vine-grower of Herault, the action of sulphur on
oidium was not long left in doubt. From 1857 sulphuring has spread
more and more, and owing to this treatment oidium is no longer
propagated to such an extent as to cause serious damage in vineyards.
To contend against this disease France alone consumes 100,000 tons
of sulphur.

How does Sulphur' Act ? — The different kinds of sulphur sold
in commerce have not the same anticryptogamic value. In a
general way that value is proportional to their pure sulphur content
and to the fineness of division. Precipitated sulphur and blown
sulphur are the products which attain the highest degree of fineness ;
sublimed sulphur and ground sulphur come very near them. In the
manufacture of ground sulphur great progress has been realized of
late years ; formerly, in fact, it required 80 lb. to obtain a result
analogous to that got from 40 lb. of sublimed sulphur, whilst now
equal weights of these two products have the same anticryptogamic
value, The adherence of the sulphur to the leaves depends on its
fineness. From this point of view blown sulphur and precipitated
sulphur are much superior to sublimed and ground sulphur, but the
former are too dear. In extensive exploitations where they used
sublimed sulphur almost exclusively, they have begun to replace the
latter by ground sulphur, which has the advantage, like blown
sulphur, of containing neither sulphuric acid nor sulphurous acid,
and thus does not burn the leaves during great heat. To obviate the

HOW SULPHUE ACTS. 45

drawbacks which sublimed sulphur has of grilling the leaves and
irritating the eyes of the operators, it has been ground with inert
bodies capable of neutralizing the acids which it contains. Neutral
mixings, with a much more gentle action on the plant, and which. act
in the same way as the neutral sulphur above described, are thus
obtained. It is thus that mixtures containing gypseous, bituminous,
calcareous ingredients are met with, which have at the same time
the advantage of favouring adherence in rainy weather. Many pre-
parations are used in the south of France, and in Algeria, where they
are specially applied for August treatment ; but a larger amount must
be used in inverse proportion to the sulphur content. It was in-
teresting to know the action of sulphur on fungi living as parasites on
plants, and several scientists devoted themselves to this study. It is
recognized that the destruction of the parasite is more rapid the
warmer the weather. With a temperature of 30°-40° C. (86°-104° F.)
destruction occurs in one to three days ; from 25° C to 30° C. (77°-86°
F.) it is already slower and takes four to five days ; below 25° C. (77° F.)
it is still more slow. According to Mach, Vesque, Sorauer, Hollrung
and Dufour, this action of sulphur on the mycelium of fungi results from
the formation of sulphurous acid, formed by the slow combustion of
sulphur under the action of the sun and heat. Pollacci, on the other
hand, believes that the sulphur is transformed into sulphuretted
hydrogen, the vapours of which have a very energetic action on fungi.
The third opinion is that of Mares and Mohr, who believe that the
sulphur acts of itself, i.e. by its own vapour. The first hypothesis
seems in fact inadmissible, for the simple reason that the sulphur
cannot be transformed into sulphurous acid except at high tempera-
tures and only by its combustion. But the sulphur does not act only
on the mycelium of the fungi where it is in contact with it ; sulphur
placed at a distance acts equally well. Spread on the soil around
the plant, it acts perfectly well if the temperature reaches 25°-30° C.
(77°-86° F.). This observation was noted as regards greenhouses by
Bergmann, Lord Eothschild's gardener in 1853, and by Viala, for
vines in the open air. If it be therefore recognized that sulphur
acts by the vapours which it emits, the nature of such vapours remains
to be examined. Sulphurous acid must not be dreamt of ; jo^^^th
of this acid in the air would burn the leaves. In warm and cold
greenhouses where the plants are unceasingly .exposed to the vapours
of the sulphur emitted from the sulphur spread on the soil, these
would not resist long if the ambient air contained sulphurous acid.
The effects of this acid, to be examined further on, are disastrous to
plants, and if it be admitted that sublimed sulphur burns plants, this
drawback is only due to the presence of sulphurous and sulphuric
acids. The formation of sulphuretted hydrogen is equally impossible.
To determine of what the nature of the vapours emitted from sulphur
when it is spread on the leaves and the soil and exposed to the
action of the air and the sun may be at temperatures of 25°-40° C.
(77°-104° F.), the author (Bourcart) made a series of laboratory experi-
ments. Sulphur mixed with dry or moist soil with or without humus
was placed in flasks with a tubulure. After having arranged these

46 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

flasks on a water-bath heated to So'^-50° C. (95°-122° F.), pure oxygen or
a simple current of ah' was passed over these mixtures and the experi-
ments kept up for eight days. At the exit from the flasks the gas
passed through a series of bottles containing substances to retain
sulphurous acid in some, hydric sulphide in others. Analyses made of
the liquids collected and of the soil mixed with sulphur gave no
trace of sulphurous acid, nor of hydrogen sulphide, hyposulphite, or
sulphuric acid. Between 25° and 50° C. (77°-122° F.) therefore sulphur
undergoes no chemical modification, and if it acts at this tempera-
ture on fungi it is by its own vapours. The odour of a greenhouse or
a vineyard is in fact never that of sulphurous acid or hydric sulphide
but that of sulphur. There is another reason in favour of the
sulphuring of vines. Sulphur would appear in fact to have a direct
action on vegetation which it renders more vigorous ; it favours
fecundation and otherwise stimulates the maturity of the grape which
generally ripens eight days earlier. It is therefore advantageous to
sulphur the vine even in the absence of cryptogamic parasites.

How should Sulphur be Applied ? — Sulphur is generally used
as a curative agent, and sometimes as a means of prevention. There
is no absolute rule for applying sulphur, the essential point is to do it
at the right time. The adhesion of sulphur can, in fact, be increased
by applying it when the plants are still covered with dew, or after
artificial moistening, but that is not indispensable, for dry sulphur
generally adheres well enough on the leaves, and chiefly on the
diseased parts. The mycelium of the Erysiphecs retained, in fact,
lumps of sulphur, which persist longer on the spots attacked than on
the healthy spots. If a persistent rain comes on or a storm in twenty-
four hours after sulphuring, it is well to repeat the operation. Sulphur-
ing may be done at any hour of the day. The dose of sulphur should
suffice to cover entirely the diseased parts. During great heat it
suffices to spread the sulphur on the ground at the foot of the plant.
Sulphuring has been used preventively in greenhouses to prevent all
cryptogamic diseases from appearing. The sulphur is spread on the
soil, or on the heating pipes once a year. The plants thus live in
a special atmosphere containing sulphur, which is opposed to the
development of fungi, without injuring the plant. Different utensils-
have been used to spread the sulphur. The most simple is the
Sablier ordinaire, a vessel of tinned iron, the bottom of which is per-
forated. It is filled with sulphur and shaken above the diseased plant.
This instrument, however, much used in the south, has the drawback
of spreading the sulphur very irregularly, and in too large quantity
on the diseased plant. The Sablier houjjjje is constructed on the
same style, but it contains meshes of wool which sift the sulphur and
distribute it more regularly. But these primitive instruments have
been almost everywhere replaced by bellows or blowers. The first was
constructed in 1852 by Gonthier, and greatly helped to popularize
sulphuring. This is the bellows still used in gardens. It consists of
a box to contain the sul])hur, which is fitted with a flat pipe at one
of its extremities and an ordinary bellows at the other. For large vine-
yards there is a more practical instrument, which carries a larger

HOW SULPHUR IS APPLIED.

47

quantity of sulphur. It is a sort of hood, called a sonfreuse, which
the workman places on his back, and which can contain 10-12 kilo-
grammes (22-26-4 lb.) of sulphur. It is filled by an air-pump, with
fan, which is wrought by a lever and a projector, the extremity of which,
ending in a Eaveneau jet, distributes the sulphur as a mist. The
complete apparatus costs 28 francs (22s. 4-8d.). It can treat 1-2
hectares (2-^-5 acres) a day. It must be perfectly cleaned after each
operation, so that the sulphuric acid of the sulphur does not damage
the metal part. The action of the sulphur on the Erysij^hecB is un-
questionable, the mycelium of which, crawling on the surface of the
organs attacked, is quickly disorganized. All the mildews may there-
fore be effectively overcome, and it suffices for the purpose to sulphur
at each approach of these parasites. But the use of sulphur does not
stop there. In certain cases, in fact, where the mycelium cannot be
destroyed, as the plant itself protects it, it destroys the external organs

Fig. 3. — Ths Regulator Sulphur Bellows.

Fig. 4.— The Torpedo Sulphur
Distributor.

of fructification, such as the Conidio-pliorea, and prevents the disease
from assuming too great an extension by that alone. It is thus that
sulphur acts on certain Pero^iosjMrecs and Black blights. Diseases of
a bacterian nature may sometimes be contended against preventively
by the disinfection of the seed by sulphur. Sulphur also acts ener-
getically on certain insects with a soft skin, and, according to Berlise,
its action is rendered more efficient by steeping it in wood tar and then
drying it. It has been found, however, to have no action on plant
lice or cochineal.

Use against Bacteria. — x^mongst the bacterian diseases of plants
the following can be treated with svilphur : —

BoUenness or Moist Gangrene of the Potato ; Potato Scab ; Botten-
ness of the Siveet Potato {Batates edulis). — Nijpels and Stone recom-
mend the use of sulphur preventively against these diseases. They
advise that the potatoes intended to be planted be rolled in flowers
of sulphur after being completely moistened so that the flowers of
sulphur adhere more completely. They also recommend flowers of
sulphur to be spread in the fuiTOWs in which the potatoes are planted.

48 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Halsted estimates that manure with 170 kilogrammes of sulphur per
hectare, say 150 lb. per acre, especially if it be accompanied with a
manuring of 175 kilogrammes per hectare (154 lb. per acre) of kainit,
gives resiilts quite as satisfactory as the usual disinfection of the
tubers by corrosive sublimate.

Nijpels, who controlled these experiments, found, however, that
his own process gave a better result.

Use against Fungi. — Amongst the Peronospora we may quote
Cystojnis candidiis, Lev. (white rust of the Cruciferae) ; Cystojnis
cubicus, de By (white rust of the Compositae). The sulphuring re-
commended by Weiss to combat white rust can have no effect, except
preventively, at the time of lifting the seed. Then several sulphurings
are applied, working preferably in the morning during the dew.

UredinecB (rusts injurious to cereals). — Sulphur has no action on
these diseases, the mycelium of which grows exclusively in the body
of the nurse plant, and the spores of which are generally formed
under the epidermis of the plant. The failure of Galloway, Hitch-
cock, Carleton, and Kellermann, was, therefore, to be foreseen. To
disinfect the soil of these fields, as well as the wheat seed already
sown, and prevent rust, Galloway tried burying sulphur in large
quantities underground, but there was no improvement. These ex-
periments, in fact, had no chance of succeeding, for it is known that
the fungi of rust are heteroic, that is to say, they possess different
methods of reproduction, which succeed each other during the course
of the year on different plants in a determined order. Thus the
barberry carries a form of fructification of the rust of wheat known
under the name of Aecidium. The infection of the fields does not
come from the seed but from the neighbourhood of certain special
plants. Amongst the Erysijihe we may quote Erysiplie communis,
Wallr. (mildew of the pea and bean). We can efficiently contend
against this fungus, either by the use of sulphur or of sulphur
and lime. Prillieux holds that sulphuring done as soon as the
first spots appear may completely save the crop invaded. In the
same category the most important of all the diseases, that which
has caused the greatest ravages, is, without doubt, the disease
known under the name of Uncinula Americana, How. (oidium
of the vine). Since the decisive researches of Mares, vine-grower of
Herault, it has been possible owing to the use of sulphur to contend
victoriously against this plague without, however, causing it to dis-
appear completely. It is quite as lively as when it first appeared, but
by the rational application of sulphur its development can be circum-
scribed and its action on crops prevented. The disease always assumes
new vigour when vine-growers are negligent in the execution of this
treatment. But so that the latter may be absolutely efficient, it must
be practised in special conditions. It is evidently difficult to fix in a
precise manner for all regions the number of sulphurings to apply
and the proj)er times, so as to protect the vine from invasion. Mois-
ture and heat are, in fact, important factors of the development of the
oidium ; the question of climate, of .exposure, of the year itself, have a
great influence on the time of treatments and their number. There

APPLICATION OF SULPHUR. 49

are two methods of sulphuring vines : (1) The rej^ressive method,
which consists in sulphuring each time the disease appears on a
certain part of the vine. That requires great attention on the part of the
vine-grower, who should not let the disease extend too far. (2) The
preventive method, which is most in use, consisting of three sulphurings
at fixed intervals. The first sulphuring is applied when as yet no oidium
has been observed at the time when the young branches reach 8-10 centi-
metres (3'2-4 inches) in length. The second at the time of flower-
ing, and the third some days before veraison, taking care to sulphur
the grapes chiefly. A supplementary sulphuring may be intercalated
between the second and the third if special conditions are favourable
to the reappearance of the disease at that moment. Dufour advises
two treatments before flowering, the first, before the complete expansion
of the leaves, the second a little before flowering. Spring sulphurings
in no way injure the plant, and they may be executed at any hour of
the day. But those which must be made in the hot season may in-
jure the vines, the leaves of which are burned by the sulphur under
the action of the sun. It is then necessary to comply with the follow-
ing indications : —

(1) To use neutral sulphurs, chiefly mixtures, containing but little
sulphur, instead of flowers of sulphur, always slightly acid, and because
the former have a much more gentle action than pure sulphur. (2)
To spread the sulphur preferably on the soil, instead of projecting it
directly on the plant. This process is not only efiicient, but without
the drawbacks described above (Viala). When these few precautions
are neglected, a large part of the crop is liable i;o be lost, owing to the
corrosive action of the sulphur. The dose to apply at each sulphuring
depends on the state of growth of the vine and the system of planting.
For the first treatment it is well to use 15-20 kilogi-ammes (33-44 lb.) of
flowers of sulphur per hectare (13-2-17'6 lb. per acre). At the time of
flowering the dose is raised to 30 kilogrammes of flowers of sulphur (66
lb. per hectare, 26"4 lb. per acre) or 50 kilogrammes (110 lb. per hectare,
44 lb. per acre) of ordinary ground sulphur. Finally for the third opera-
tion it is necessary to spread 40 kilogrammes of sublimed sulphur (88 lb.
per hectare, 35*2 lb. per acre) or 60-70 kilogrammes of ground sulphur
per hectare (52*8-61"6 lb. per acre) and about 100 kilogrammes of Apt
sulphur (220 lb. per hectare, 88 lb. per acre). When the ground sul-
phur is as fine as the sublimed, the quantity to use will be the same as
for the latter. To preserve hothouse vines it suflices to spread sulphur
on the soil once a year ; any invasion is prevented by this single
treatment. Since other cryptogamic diseases — mildew, black rot, and
others — have ravished the vine, attempts have been made to reduce
the multiplicity of treatments, and cupric powders have been mixed
with the sulphur, the isolated action of which is recognized as effica-
cious against these diseases. It has been advised to add 5 per cent of
blue vitriol to the sulphur, or to incorporate sulphur in the cupric
bouillies. There is even on the market a preparation known under the
name of " cuprocalcite," which has in Germany the reputation of being
at 25° more active than sulphur (Mohr). This product would appear
to form a protective coat on the leaves, and by its adherence preserves

4

50 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

the plants longer against new invasions of oidium. But this opinion
is not accepted, and it is generally believed that sulphur does not act
in the presence of common salt. Pollacci and P. Viala condemn these
mixtures, the first, because he believes that sulphur is not oxidized in
the presence of copper salts, the second, because the experiments
made at the Montpellier schools showed tbat these mixtures could
neither prevent nor arrest the oidium and mildew. Mach and Mares
agree upon that point, and this is the explanation : Copper salts have,
in fact, the drawback of catching the vapours of sulphur, converting
them into insoluble and inactive copper sulphide. If it be taken that
sulphur acts by its vapours, it is evident that the action of the product
is destroyed. These remarks are also of value in regulating the
double treatment with sulphur and cupric bouillies. Since the intro-
duction into viticultural practice of sulphating against mildew and
black rot, the question of ascertaining whether siilphuring should be
done before sulphating, or vice versa, has been often discussed.
Laurent advises to precede the first sulphuring by the first sulphating,
the second sulphating being done after flowering. But as the sulphur
acts for four to five days, it is well to let this interval elapse between
sulphuring and sulphating, so that these two treatments do not mutually
destroy the effects of each other.

Drawbacks to Sulphuring. — Workmen engaged in sulphuring
with sublimed sulphur sometimes have bad eyes, especially if they do
not take the precaution to work with the back to the wind. To obviate
this drawback, it is well to make them wear spectacles with cloth side-
pieces, and to make them bathe the eyes several times a day with fresh
water. Sulphur also gives sometimes a slight taste to the wine, owing
to hydrogen sulphide, formed during fermentation. But this drawback
is always caused by too dilatory sulphuring. If the wine still contains
sugar, and is fermenting, it must be drawn off after fining in a cool
cellar. If it does not contain sugar and already drawn off, it must
be protected from any new production of hydrogen sulphide by the
following treatment : In the case of wine with a feeble taste, one or
two drawings off, during which the liquid is allowed to flow in a thin
stream into a tank, may suffice to let the hydrogen sulphide escape
into the air. L. Mathieu advises to run the wine in a stream over a
plate of polished copper, so that it runs into a film : one part of the
gas escapes into the air, the other is fixed by the copper. The copper
plate must be cleaned from time to time with emery paper when it
is blackened. If these methods do not suffice, sulphurous acid must be
added to the wine as bisulphite of potash (metabisulphite of potash),
about 10 grammes per hectolitre, say 7 grains per gallon. The two
gases mutually destroy each other with the deposition of sulphur,
which simple fining after a few days will completely carry down into
the lees. By using for the last operation only 40 kilogrammes of
sublimed sulphur per hectare (35"2 lb. per acre) or a stronger dose of
Apt sulphur or any other product of low sulphur content, this draw-
back need not be feared.

Oidium Fragarice, Harz (oidium of the strawberry). — Sulphuring

USE OF SULPHUE AGAINST FUNGI. 51

gives excelleat results (Sorauer) ; Phyllactinia suffulta, Eebent. (mildew
of the hazel and the ash-tree) ; ^licrosjylKera Gross idar ice, Wallr.
(mildew of the gooseberry leaf). Nijpels and Sirodot affirm the success
of sulphuring.

Spharotheca Castagnei (mildew of the hop). — Nijpels recommends
to fight it, like the oidium of the vine, by three sulphurings, the first
before flowering, the second during flowering, and the third when the
cones are completely developed.

SpharotJicca jjannosa, Lev. (mildew of the rose and the peach). —
By methodical sulphuring, applied as soon as the disease appears, the
rose bushes, most sensitive to this mildew, may be quickly cured.
Vesque, Briosi, and Eegel regard sulphur as the most sure and efficient
method. The curative treatment of the peach miller (meunier du
pecher) also consists in two or three sulphurings applied after ten days'
interval.

Fiimagine (smut of fruit trees). — Sulphur has the same action on
capnodium as on mildews, but to be completely successful it is necessary
to fight the lice and the cochineal, which are the first cause of the
fumagine. Amongst the Sphaeraceae capable of being fought with
sulphur there may be mentioned : —

Dematophora necatrix (white root rot of vine, etc.). — Narbonne has
tried sulphur against vine rot. He advises to pull up the most badly
attacked stocks ; to lay bare the stocks not so badly attacked as deep as
possible, and dust the roots abundantly with sulphur. It is useful to
renew this operation several times before the stocks are covered up.
again.

Black Blights, the mycelium of which is in the interior of the plant,
are more difficult to reach by sulphur, but as their organs of fructifica-
tion, the conidiophores, are formed on the surface of the leaf, those-
organs can be got at by sulphur. The propagation of the disease is
thus fettered. In this class are : —

Sphcerella Fragarice, Sacc. (spots of the leaf of the strawberry). —
This very common and often harmless disease may, when it is
intensely severe, stop the development, and entail the death of the
plant. Nijpels recommends sulphur mixed with Hme to prevent the
disease on young plants.

Septoria Petroselini, Dmz. (var. Ap. Br. et Cav.), injurious to celery,
is fought by sulphuring, like the Cercospora Apii (Duggar, Baily, and
Sturgis).

Gloeosporium avipelophagum, Sacc. (grape rot). — This disease
may be fought by sulphuring, but to succeed it must be applied in
the beginning of the attack, so as to hinder the germination of the
spores. To stimulate the action of the sulphur it is mixed with pul-
verized iron sulphate or lime. Paul Sol advises a very abundant first
sulphuring before flowering, to distribute them plentifully in the same
spots, and then to sow ferrous sulphate broadcast, 50 kilogrammes per
hectare (44 lb. per acre). If the epidemic be not arrested it is necessary
to renew this treatment. Viala obtained good results from mixture of
sulphur and lime applied in the following proportions : —

52 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

TABLE X. — Shoiving Proportions of Sulphur and Lime used in Mixtures against
Anthracnose at Different Stages of Treatment.

First Second Third

treatment. treatment. treatment.
Sulphur ... 4 parts 3 parts 2 parts

Lime . . . 5 „ 2 „ 3 „

The first treatment is applied when the shoots are 8-10 centimetres
(3-2-4 inches), the succeeding treatments every fifteen days. Briosi
tells us that this sulphur and lime treatment is in actual use to fight
anthracnose in the provinces of Pavia, Cuneo, and Messina. Solutions
of sulphate of iron are reserved for winter treatment.

Cercosjiora Apii, Fr. (celery leaf blight). — Sturgis, Duggar, and
Baily agree as to the efficacy of sulphur in fighting this disease when
applied on a hot day, in which case sulphur is superior to all other
■chemical agents. Scribner dissents, and asserts that sulphur has little
■or no action. It is evident that sulphur cannot reach the fungus
developed in the interior of the leaf, but in destroying the organs of
fructification it may stop the propagation of the disease.

Cladospori'um fulviwi, Cooke (tomato leaf rust). — Mohr and Nijpels
found that sulphur acts more effectively than copper salts to arrest
this disease.

Clematite {large flowered), variety of Clematis patens, lanuginosa et
florida, disease of. — This disease, to which many fine ornamental plants
succumb, is attributed to the Aecidium clematidis or Aecidium engleria-
num, sometimes to Nematodes. The clematites disease cannot be
circumvented by copper salts. But Fourrat found it possible to pre-
vent it by laying bare the root, which he dusted with sulphur and
afterwards covered with soil. The author's (Bourcart) experiments
did not confirm this result.

Use of Sulphur against Insects. — Crioceris Asparagi, L. — Miss ^
Ormerod killed these insects by a spray consisting of 1 lb. of soap,
1 lb. of sublimed sulphur, and 1 lb. of soot, in 10 gallons of water.

Haltica nemorum, L. (earth flea). — These minute Coleoptera gnaw
the leaves of young plants, and, owing to their numbers, cause great
damage. Their destructive work may be stopped by dusting the
plants, whilst still small, with a mixture consisting of 3 kilogrammes
(6-6 lb.) of sublimed sulphur, 5 kilogrammes (11 lb.) of soot, and 50
litres (If bushels) of quicklime per hectare (2-^ acres). In the author's
opinion the quicklime would have a preponderant action.

Haltica ampelop)haga, Guer. (altise of the vine). — D'Aurelles de
Paladines proposes to fight them with sublimed sulphur, or better, pre-
cipitated sulphur from gasworks. A more energetic method consists
in using a mixture of black snuff, 12-15 kilogrammes, and Apt sulphur,
85-88 kilogrammes per hectare (10-4:-13-2 lb. and 74-8-77-4 lb. per
acre). A mixture of Apt sulphur and newly slaked lime may also be
used.

Ephippigera Bitterensis {Ephippiger of Beziers), Ephippigera
Vitium (vine ephippiger). — These grasshoppers devour the leaves, the

' Not M. (= Monsieur as in original).

USE OF SULPHUR AGAINST INSECTS, 53

young vine shoots, and the grapes. The crop is sometimes seriously-
compromised in the South of France by the great number of these
Locustides. The grapes may be protected from their voracity by
dusting the bunches in June, at the time when the Ephippigeres-
appear, with a mixtiire containing equal parts of sulphur and lime
(Valette).

Eriocampa adumbrata (slug worm, or slimy caterpillar of pear-tret
saw-fly). — Goethe recommends ground sulphur against the sticky larvae
of this saw-fly. This treatment is in common use in the Tyrol (Fischer).

Carpocapsa Po^nonella, L. (codlin moth), the grub of which renders
apples wormy. The sulphuring of apple trees, after flowering, is
very ef&cient in drawing off the butterfly and preventing it laying its
eggs on the young apples.

Phylloxera vastatrix (phylloxera of the vine). — Two processes have
been used ; that of Saintpierre, tried unsuccessfully, is quoted as a
matter of history. It consisted in making a hole in the vine with a
gimlet and in introducing 3 grammes of sulphur, then in re-closing the
hole with a plug. The second process, that of Aman-Vigie, consisted in
injecting into the soil, by means of a special bellows, a mixture of sulphur
and sulphurous acid. But these vapours do not diffuse well in the soil
and only penetrate it imperfectly. Henneguy, after trying this process,
concluded that, applied in July and August, it exerted an unfavourable
action on the propagation of this insect. If it be not capable of entirely
freeing the vine from its parasite, it kills a sufiicient number to allow
the plant to live normally.

Use against Acari. — Tetranychus telarius, L. (red spider). — In
hothouses it may be fought with sulphur. Maynard advises to heat
the sulphur in a pot till it gives off fumes without inflaming. This
operation should be renewed two or three times a week for several
months. Sturgis asserts that this process destroys at the same time
the Peronospora, De By, which resists repeated sulphurings in the
open air.

Tetranychus hiocidatus, W.M. (red spider of tea). — Playfair recom-
mends to destroy it to spread on the tea before cutting 50 to 60 kilo-
grammes of sulphur per hectare (44-52-8 lb. per acre).

Eriophyes Vitis, Land., syn. Phytoptus Vitis (erinosis of the vine).
— Erinosis may be arrested by repeated sulphuring, commencing some-
time after the formation of the buds, when the branches are 8-10
centimetres ('3'2-4 inches) in length. Couderc advises a hot day in
spring for the operation.

Eriophyes Malinus, Nal., syn. Eriniuin Malinum (erinosis of apple
and pear). — Sulphuring applied from bottom to top produces a satis-
factory effect.

Eriophyes Piri, Pgst. C. (brown rust of the pear), syn. Phytoptus
Piri. — Repeated sulphurings are efficacious if applied before the ap-
pearance of the disease. .

Phyllocop)tes Schlechtendali, Nal. (browning of leaves of pear and
apple trees). — This fungus is readily accessible to insecticides, and
sulphur acts in a sure manner.

CHAPTER III.
CARBON BISULPHIDE, CS^.

5. Carbon Disulphide. — Preparation. — By projecting fragments
of sulphur on to red-hot coals. On the large scale, vertical cast-iron
cylinders built in masonry are used. They are filled with charcoal,
which is kindled. As soon as it has reached a sufficient heat, the
sulphur is introduced, gradually, through a side pipe. The sulphur
melts, then vaporizes, and combines as vapour with the incandescent
carbon. The gas escapes through a top pipe which communicates with
two reservoirs, the first of which retains entrained sulphur, the second,
which is cooled by a bath of cold water, condense? the vapours of carbon
disulphide. The uncondensed gases, which are hydrocarbides, escape
through a top pipe. Carbon disulphide flows into zinc reservoirs, where
it is preserved under water. It may be rectified by drying it over
fused calcium chloride and finally distilling it on a water-bath. For
agricultural purposes, this rectification is useless ; carbon disulphide
in that case is led directly from the tank into the wrought- iron barrels,
in which it is dispatched. The annual production of this product in
France exceeds 2000 tons, almost the whole of which is used in
agriculture.

Properties. — Carbon disulphide is a colourless liquid w^ith a
pleasant smell when it is pure, but almost always fetid on account of
impurities which it contains. It is a very mobile liquid, which boils
at 45° C. (123° F.j, and consequently vaporizes with rapidity in an
open vessel. Its vapours form with air mixtures capable, like coal
gas, of detonating at the approach of a flame or an incandescent ob-
ject. Owing to its ready inflammability the manipulation of carbon
disulphide necessitates great precautions, and should be carried out
far from any source of heat or flame, and wholly in the open air.
Smoking is therefore forbidden in the sheds where it is handled, and
when it is employed in the field the iron barrels containing this pro-
duct should be deposited far from dwellings, and protected from the
sun. To prevent the losses which would result from the evaporation
from a cask being emptied, a good precaution is to run a small quantity
of water into the cask. The water forms on the surface of the carbon
disulphide a protecting layer, for the density of the water is lower
than that of the sulphide. To ascertain the quantity of this liquid
left in a barrel, a rod coated with tallow may he dipped into it. The
rod will come back clean on all the part which touched the carbon
disulphide, this product being a solvent for all fats. Carbon disulphide

(54)

ACTION OF CARBON BISULPHIDE ON PLANTS. 55

is almost insoluble in water ; the latter can dissolve at 1000th part of
its weight. On the other hand, it is miscible, in all proportions, with
absolute alcohol, and with a great number of organic bodies rich in
carbon,. such as fats, resins, camphors, vaselines. It exercises a very .
decided deleterious action on the animal economy ; it produces head-
ache and nausea, and after a certain time it may debilitate the
nervous system. Its intoxications are not generally dangerous, for
they cease by the simple removal of the cause. The workmen who
handle this product are subject to its effects if precautions are not
taken to protect them from the vapours. A dose of 120-150 grammes
absorbed by the alimentary canal kills a dog. Carbon disulphide is
used in medicine as an antiseptic against typhus, cholera, tuberculosis
(Chiandi-Bey), against cancers (Whittaker), intestinal catarrh, and
especially infectious diarrhoea (Dujardin Beaumetz), finally as an
emmenagogue and anaesthetic. In the form of vapour it is used against
helminthiasis and different diseases of the skin (Lewin).

Action of Carbon Disulphide on Plants. — Carbon disulphide is
poisonous to plants. According to Sandsten it stops the movements
of the protoplasm as soon as the plant comes in contact with even
a very small dose of this agent. It is more injurious to the plant the
more its application corresponds with a greater activity of the sap.
The same doses used in winter without prejudicing the plants may
become deadly in spring or in summer. Carbon disulphide is as in-
jurious to the roots as to the part above ground. Plants should never
therefore come in contact with pure carbon disulphide, nor into an
atmosphere too highly charged with vapours of this insecticide.
According to the experiments of Boiteau the roots may die if they are
4 inches from the spot where the carbon disulphide was injected
into the soil. At the dose of 5 c.c. of carbon disulphide per 4 litres
of soil, say at the rate of 5 oz. measures of carbon disulphide per
4000 oz. measures {B^ bushels) of soil, the vine would inevitably die ;
2 c.c. of the same product injected into the same quantity of soil
(4 litres) might be injurious to a potted plant. The moisture of the
soil tones down to a certain extent the injurious action of carbon
disulphide ; its effect is so much the more injurious to the soil the more
dry the soil and the higher the temperature. Just as much as con-
tact with carbon disulphide and its vapours in strong doses are deadly
to plants, so also to a like extent are weak doses indifferent to them
when they are brought into contact with the roots either in 1 per cent
solution in water, or in the form of vapour. The strong doses applied
at the beginning of the phylloxeric invasion always entail the
death of the vine, as well as that of its formidable parasite, whilst the
cultural doses now used not only do not injure the vine but impart
to it exceptional vigour. However, carbon disulphide prodvices even
in a small dose, as Vincey has observed, an injurious action on the
plant ; but this action is only a passing one and hardly perceptible.
In this way vines treated with small doses of carbon disulphide before
the unhairing of the buds are thrown back seven to eight days beyond
those not treated. Summer treatment always entails a passing
slackening in the growth of the plant. Different plants vary in their

56 INSECTICIDES, FUNGICIDES, AND WEED KILLEES,

sensitiveness to this reagent, and it has been observed, for example, that
trees generally support larger doses than annual plants. The aerial
part of the plant also withstands carbon disulphide up to a certain
limit, soapy emulsions and fumigations of carbon disulphide which,
according to Morren, are not toxic up to y-gVo- Goethe has observed
that the vine can stand fumigations for twelve hours at 20° C. without
suffering. Before the ascent of the sap the vapours of carbon
disulphide may be prolonged without injury, and the dose in the same
way. Targioni-Tozetti found that the dose of 2 per cent of carbon
disulphide in soapy emulsion was the limit without injury to the leaves,
whilst with petrol the dose was 2'5 per cent. A strong dose of carbon
disulphide dries the leaves without altering the colour. Seeds like-
wise undergo the toxic effect of this insecticide, but according to
Prillieux their power to withstand it varies with the species. Cereals,
for example, lose 50 per cent of their germinative capacity alter eight
days of fumigation, whilst beet seeds undergo no alteration after three
weeks of this same treatment. Coupin, who examined the action of
this agent on grain compared with ether and chloroform, found that
these two last bodies had no injurious action on wheat grain when
the protoplasm is at rest, whilst carbon disulphide is always in-
jurious thereto. However, if owing to moisture there is swelling
and the protoplasm is active, ether also becomes injurious to the
grain in the dose of 3-7 c.c. for 10 litres of air (3'7 in 10,000).
According to Fantecchi's experiments seed corn dipped two minutes
in carbon disulphide and afterwards dried in the air loses 10 per cent ;
dipped for one minute only in this insecticide then exposed after-
wards for twenty-four hours in an atmosphere of carbon disulphide,
it undergoes a loss of 50 per cent. The grain suffers the same loss
if exposed for twenty-four hours in a closed vessel at 30° C. (86° F.) ;
in an atmosphere containing 2 kilogrammes of carbon disulphide per
cubic metre if the heat be raised to 40° C. (104° F.) the loss will be
100 per cent.

Action of Carbon Disulphide on Insects. — Carbon disulphide
is one of the most efficacious of insecticides ; it diffuses very rapidly in
virtue of its great mobility and its very low boiling-point. Its
anaesthetic and asphyxiant properties act very rapidly on the vitality
of the insects which die paralysed in breathing it. Insects are gener-
ally more sensitive to the action of carbon disulphide than plants, so
that by only using doses injurious to insects they can be overcome
without hurting the plant. When an atmosphere saturated with the
vapour of carbon disulphide can be created around the insects or
their larvae they die in a few seconds (Mouillefert). Phylloxera is so
killed in thirty seconds. If the atmosphere only contains 0'5 per
cent of carbon disulphide vapours (say 0-0016 of liquid sulphide) the
action must last twenty-four hours to kill the phylloxera. An
atmosphere containing 0'4 pei' cent of CS._, vapour easily kills, in
fifteen minutes, grubs, butterflies, grasshoppers, lice, and Coleoptera
(balls). Injected into the soil to a depth of 4 inches doses of 40 grammes
per square metre (say 1., oz. pur square yard) for heavy ground and
30 f:,ram:nes (say 1 oz. per square yard) for dry, light soil, suffices

INFLUENCE OF CARBON BISULPHIDE ON FERTILITY. 57

to kill all the insects in that layer of earth. But solutions and emul-
sions of CSo do not act so rapidly nor so energetically as the vapour
in a closed space. A 1 per cent solution does not kill the phylloxera
until after twenty-four hours' immersion. Grubs strongly resist it. •
Those of the gypsy moth, Ocneria dispar, L., resist soapy emulsions
containing up to 10 per cent CS.,. Burleso Dufour came to the same
conclusions after trying to kill the cochylis {Conchy lis ambignella,
Hubn) by emulsions containing 3 per cent and 10 per cent of CSg.

Action of CS^ on Fungi. — This insecticide only acts on fungi in
very strong doses, and is only used to kill root rot.

Influence of CSo on Fertility of Soil. — Carbon bisulphide, far
from injuring the soil into which it is injected, as believed at the out-
set of its use in vineyards invaded by the phylloxera, exerts even in
strong doses a favourable influence thereon. Aime Girard was the
first to observe that carbon disulphide injected into the soil produced
salutary effects on the soil treated, and greatly improved exhausted
soils. In Alsace-Lorraine, where the antiphylloxeric treatment to
extinction has so long been used, the marvellous action of carbon
disulphide has been remarked by Oberlin. The latter, who has more
especially studied the soil cure, has obtained surprising results. The
culture of the vine being rigorously forbidden during the next ten
years after the extinction treatment, the laud was utilized for other
crops. Now it was found that in all these soils all species of plants
developed in a surprising manner, and that the rotatiois in use on
non-disinfected ground were unnecess-ary on the former ; CS^ re-
generates exhausted soils and allows continuous growing of the same
crop. All papilionaceae may be profitably cultivated on lucerne
ground ; for example, if the soil of the latter is previously tilled and
disinfected, whilst in ordinary cropping one plant cannot usually be
grown after another of the same nature without intermediate crops ;
CSg therefore renders rotations unnecessary, and enables the same
plant to be cultivated for several years in succession. Oberlin, who
has greatly helped to popularize carbon disulphide, got, like Girard, a
double crop of trefoil after disinfecting the soil, and an appreciably
increased yield with grain crops, beets, potatoes, and farm crops
generally. In a tares (Vicia villosa) experimental field, treated with
CS2, Oberlin obtained, in 1893, 45 tons of green fodder per hectare
(18 tons per acre), whilst in a non-disinfected field, used as a test, the
yield was only 19 tons per hectare (7"6 tons per acre). He also ex-
perimented with haricots, and obtained by weight per are 85 kilo-
grammes in non-treated ground, and 125 kilogrammes in treated
ground. Oberlin disinfects the soil as follows : Holes about 12
inches deep are excavated by an iron bar and 25 grammes of CSg
run into each hole and the holes quickly closed ; 10 kilogrammes of
carbon disulphide must be buried per are. Three weeks after this
treatment sow the seeds. Practical experiments on vines gave equally
good results. Oberlin first, then Dufour, found that vineyards, before
being replanted, have no need, as generally believed, of a rest, nor of
any improvement by an intermediate crop after treatment with CS2.
The new vine can, in fact, be replanted as soon as the old stocks have

58 INSECTICIDES, FUNGICIDES, AND WEED EILLEES.

been extirpated if the following procedure be adopted : Trench the ground
to 65 centimetres (2 feet 2 inches), then at a distance of 50 centimetres
(20 inches) apart in every direction dig holes of 50-60 centimeters (20-
24 inches) deep. Eun into each 100 grammes (say 3^ oz.) say 40
kilogrammes (88 lb.) per acre, and close the holes quickly ; the soil
must remain in this condition until the spring, when the new planta-
tion will be made. In vineyards reconstructed in that way the young
vine stocks yielded in the third year 30 hectolitres (660 gallons) ; the
fourth yeai', 110 hectolitres (2200 gallons) ; whilst the test vineyard
non-treated only gave 74 hectolitres (1528 gallons). Here is, by a re-
port of the Baden Botanical Station, a curious result obtained in onion-
growing. Soils, completely exhausted by the culture of this plant,
were appreciably improved by disinfection by carbon disulphide.
Holes 40 centimetres deep, bored 50 by 50 centimetres (20 inches) in
every direction, received 100-300 grammes of carbon disulphide, and the
produce, which had fallen to 14 units per square metre, was raised to
22 by the dose of 400-800 grammes per square metre, and to 26 by a
dose of 1000 grammes (2-2 lb.). These improvements, due to carbon
disulphide, are very surprising, and efforts have been made to ascertain
how this product acts on the soil, since it is void of any nutritive
function, and how it can be the cause of intense yields in an exhausted
soil.^ There are a large number of parasites, both insects and fungi,
which live in the soil at the expense of the plants, and looking at their
grand opportunities for multiplying when the same plant is grown
continuously for several years the exhaustion of the soil, it will be
readily understood, is due solely to this accumulation of parasites which,
attacking the plant by the roots, remove from it the means of nourish-
ing itself. Carbon disulphide, injected into the soil, by destroying all
these parasites, restores to the soil its primitive purity, and the plant,
undisturbed by parasites, develops normally, and profits, by fertilizers,
to give large crops. Carbon disulphide acts like the bare fallow, which
also remedies soil exhaustion. By suppi'essing food from the parasites
accumulated in the soil for a certain time the latter greatly disappear.
Carbon disulphide is more effective than bare fallow, and gives com-
plete and immediate results, because it enables the soil to be com-
pletely disinfected and to utilize it at once for a new crop. The in-
fection of the soil is caused by fungi : Dematophora necatrix, Hartig ;
Armillaria Mellea, Quelet ; Boeslerm hypogaea, Thum. et Pass. ; by the
AnguilluLides, Heterodera SchaclitH, Schm., and H. Radicola, Gr., and
insects, the larvae of which take several years to accomplish their evolu-
tion, such as the Elaterides (click beetles), cockchafers, etc. All these
parasites multiply greatly, especially when they are omnivorous and not
disturbed by rotations ; they are, in themselves alone, capable of pre-
venting a plant from producing normal crops. Carbon disulphide in
large doses creates in the soil a sufficiently poisonous atmosphere to kill
them, and so sterilize the ground being cropped. Contrary to Foex,
Dufour, Oberlin, and Couanon, whose researches leave no doubt as to
the action of carbon disulphideon the mycelium of different cryptogams,

' Note by Translator. — The onion is a sulphur-loving plant. The reason for
increase in crop is obvious.

HISTORY OF CARBON BISULPHIDE. 59

Perrault does not admit so great a destructive action on cryptogams.
He holds that if CS„ acted in that way on insects and cryptogams, it
would also act on the useful micro-organisms, which live, in symbiosis,
with a great number of our cultivated plants. There exist, in fact,
in the soil microbes indispensable to the formation of nitrates, to the
decomposition of organic matter ; and microscopic organs which, pro-
ducing small nodosites on the roots, fulfil the function of conveying
atmospheric nitrogen under an assimilable form (Wilfahrt, Nobbe,
Hiltner, and Hellriegel). If PeiTault's contention were well founded the
fertilizing action of carbon disulphide would be illusory, because that
state of things would have to be remedied by applying to the soil a
strong dose of nitrogen, not as organic manure, but in the form of
saltpetre. It has, however, recently been shown that carbon disul-
phide only temporaril}^ affects the bacteria useful to agriculture, and
Wollny formulates the results obtained up to now as to the action of
carbon disulphide thus : —

(1) The introduction of carbon disulphide into arable land during
the period of vegetation has the effect, according to the quantity ap-
plied, of either completely destroying vegetable life, or of causing tem-
porary trouble. (2) When the sulphide is applied several months before
cultivating the soil, the fertility of the soil is greatly enhanced. This
action of the sulphide extends, according to the quantity used, over
one or more periods of vegetation, and it is followed, if manure be not
employed, by an important decrease in the yield of the field treated.
The lower organisms which play an active role in the decomposition
of organic matter and in the formation of nitrates in the soil, as well
as the bacteria of the radicular nodosites of the leguminosae, are not
killed even by strong doses of carbon disulphide ; their activity only
receives a temporary check, to resume afterwards all its energy.

Use, — History. — Baron Thenard was the first who drew attention
to the services which carbon disulphide might render in destroying
the phylloxera of the vine, but his experiments, made in 1869, owing
to the then defective methods of applying this insecticide, did not give
the result expected. The method of application and the doses used
play, in fact, a role of very great importance in the success of this
treatment, and it was not until after the researches of Monestier,
Lautaud, and Ortoman that carbon disulphide gave some good results.
In 1873 these scientific observers concluded that carbon disulphide
i3 not injurious, except in the liquid state, when it is brought into
direct contact with the roots of plants ; it is necessary therefore, so
as to remedy this drawback, to inject the liquid at a certain distance
from the plant in such a way that the vapours disengaged form around
the roots an atmosphere sufficiently toxic to kill the parasites. With
this end in view they recommended that the carbon disulphide be
caused to act from below upwards by depositing this agent in holes
pierced to a depth of 80 centimetres (3H inches) ; although based on
an excellent principle, the use of carbon disulphide too often caused
the death of the vine, for the doses used, which varied from 150-375
grammes per stock, were too strong. Experiments by the Montpellier
Agricultural Society, due to the initiative of the Yiticultural Associa-

60 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

tion of Libourne, lad to a gradual deci-ease in the dose, which was
definitely regulated to 12-20 grammes only per square metre, say
24-28 grammes per stock. Dumas' researches showed that even
3 grammes per square metre (y^ oz. per square yard) were sufficient to
attain the object in view. Owing to the support of the Paris-Lyon-
Mediterranee (? Eailway), and the Minister of Agriculture, who estab-
lished a superior Phylloxera Commission and Vigilance Committees
in the districts invaded, carbon disulphide was employed on the large
scale.

The efficacy of carbon disulphide in the struggle against the phyl-
loxera was determined accurately, and the conditions under which it
acted were determined by the learned researches of Crolas, Marion,
and Jaussan. At the present time the utility of carbon disulphide is
no longer in doubt ; it has rendered, and renders, undoubted services,
and its use has become universal. To give an idea thereof it will
sufiice to say that, in 1895, 60,000 hectares (150,000 acres) of vines
were treated with carbon disulphide. This product is, moreover,
destined to render the same services in agriculture and horticulture,
and owing to its remarkable insecticide properties it may become, like
manures, an indispensable auxiliary to farmers. It is already used
against a great number of insects whose larvae live underground at
the expense of the roots, and the good results obtained have led to its
use against the ravagers of the aerial part of the plant. There, how-
ever, its success has not been so great.

Its method of use varies according to the parasite to be destroyed.
The best results are got when an atmosphere containing a dose
poisonous to insects and their larvae can be produced. This condition
is easily realized underground, in granaries, hothouses, and under
tents of impermeable cloth, with which small-sized trees may be
covered. In these different cases liquid carbon disulphide is always
used, and acts by evaporation. When an asphyxiating atmosphere
has to be produced underground, the carbon disulphide is introduced
to a certain depth by a pal-injector, which is regulated for the desired
dose. In soils favourable to the diffusion of gases, such as those which
are not too compact nor too moist, the vapours of carbon disulphide, in
a dose of 20 grammes (307 grains) spread within a radius of 30-35 centi-
metres (10-12 inches) around the spot where it has been poured. These
vapours remain long enough in the soil for the toxic atmosphere to
produce its effect. According to the parasites to be got rid of the dose
is diminished or increased, and injected to a variable depth. There
are cases where the roots of the vme descend so deeply that the carbon
disulphide must be injected to 80 centimetres (314 inches), whilst to kill
the larva3 living a few centimetres from the surface, one does not go
down more than 20 centimetres (7"8 inches). To use carbon disul-
phide it is therefore necessary (1) To ascertain the exact spot where
the parasites to be killed are, first making a trench and making it at
about 20 centimetres (7 "8 inches) below the invaded zone. (2) To
choose the moment when the soil is in such condition as to allow the
diffusion of carbon disulphide vapours into the interior of the mass,
whilst at the same time it places the greatest possible obstacles in the

HISTORY OF CARBON DISULPHIDE. 61

way of their loss. This moment varies with the nature of the soil to
be treated. A clay soil, for instance, cannot realize favourable condi-
tions when it is saturated with water, or when it is cracked by drought.
On the contrary, a sandy soil, after a slight rain, is in favourable con-
dition. The most propitious moment is when the soil presents a
certain interior mobility and a great enough density on the surface.
In these conditions the vapour of carbon disulphide easily diffuses
around the roots, and remains imprisoned by the hard surface, which
forms a sort of envelope. Those advantageous conditions may be
realized artifically by injecting carbon disulphide into a very dry soil
and watering the surface soil, after having carefully plugged the holes.
(3) Never to stir the soil after treatment, for the carbon disulphide,
already very volatile, would, in certain instances, escape into the a'r
without producing its effect ; it is therefore necessary, so as to employ
it with success, to maintain it as long as possible in the infected zone.
To attain this end recourse has been had to two preparations, which
allow a less rapid evaporation of carbon disulphide.

Vaselinated Sulphide. — In 1874 Bouttin proposed a mixture of
carbon disulphide and nut oil. Cubes of wood, imbibed with sulphide,
and covered with silicate of soda have been tried but neither of these
processes have given good results. Vaselinated sulphide was invented
in 1887 by Dr. A. Meunier and examined by Cazeneuve : vaseline forms
an emulsion with carbon disulphide and prevents it from evaporating
rapidly. It was hoped, owing thereto, to lessen the chances of evapora-
tion into the atmosphere and to prolong its action in the soil. Mixtures
were tried of equal parts of the two substances, or of 30 per cent of
vaseline and 70 per cent of carbon disulphide. In 1890, 250 metric
tons of these substances were used in viticulture. It has been observed
by Vermorel and Jossinet that the dose of 20 grammes of liquid carbon
disulphide placed in each hole 35-40 centimetres round the vine suffices
to kill the phylloxera, but when mixed with vaseline this quantity is
not enough. However, if the holes be brought to within 10-15 centi-
metres of the stock, the conditions favourable to the action of this
preparation are improved. Marion and Gastine conclude that there
is no advantage in this mixture, since the dose of sulphide must be
greater to give the same result. They further remark : If more than
50 per cent of vaseline be incorporated in the carbon disulphide, the
evaporation which is produced during injection is as great as when
employed pure, and finally the vaseline retains about 15 per cent of
sulphide which it only cedes very slowly, and which remains without
effect. Wooden cubes impregnated with sulphide as well as mixtures
of carbon disulphide and heavy oils, tested by Marion and Gastine as
far back as 1877, gave no advantageous results, and the pure sulphide
should be preferred to all these preparations. It is a great error to
imagine that carbon disulphide must develop slowly to produce a
salutary effect. For the action of the sulphide to be effective, what is
required, above all, is to create almost instantaneously an atmosphere
highly charged with poisonous vapours around the radicular system
invaded by the parasites and to maintain it there as long as possible.
To slacken the evaporation of the carbon disulphide is to remove from

62 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

it one of its most precious properties, that of its great diffusibility.
A slower evaporation will not create an atmosphere sufficiently toxic
t3 kill the parasites. A great number of volatile substances, very
poisonous to the phylloxera and used in the same conditions as carbon
disulphide, have never been able to equal it, as their diffusion in the
soil was too slow. To avoid the loss of carbon disulphide in the usual
treatment with the pal-injector, the use of gelatinized capsules con-
taining a dose has been tried. These capsules are arranged in holes
made with a pal-injector, and afterwards plugged. Under the action
of the moisture of the soil the gelatine finally dissolves, the sulphide
flows out into the soil and rapidly evaporates, The operator has thus
a convenient time without fearing loss of the sulphide to plug the
holes and to water the surface of the soil to imprison the vapour
after the rupture of the capsules. In spite of the apparent advantages
of this process, it has had to be renounced in viticulture because the
disengagement of sulphide was too irregular and not simultaneous in
the zone treated. In horticulture these capsules are handy because
they are easy to use and as they avoid the purchase of a pal-injector.
(4) To distribute uniformly the sulphide in all the soil to be treated.
This is done by placing the holes at equal distances from each other,
and by using instruments which enable equal doses of this substance
to penetrate into the soil. Carbon disulphide may be injected into the
soil during almost the whole year. However, it is less injurious to
the plant if the operation be performed during the time vegetation is-
at rest. In any case, its use should be avoided during the flowering
period and when the fruit approaches maturity.

Instruments Necessary for applying Carbon Disulphide. — The
pal-injector already mentioned must be placed in the first rank of
instruments intended for this purpose. It is a sort of compression
pump, intended to convey a known dose of carbon disulphide to a
certain depth. The loal-Gastine, which may serve as a type, consists
of a reservoir, in zinc or copper, intended to contain carbon disulphide.
This instrument possesses, in its interior, the body of a pump in which
a piston moves. Under the pressure of the latter a valve opens and
closes the opening of a long channelled tube, which penetrates into
the earth. An aperture near the shai'p end lets the sulphide escape.
Two handles and a pedal serve as a point of suppoi't to the workman.
The output can be regulated at will. In hard and gravelly soils the
workman is preceded by an assistant, who pierces the holes with an
iron crowbar called Avant-pal, the tube of the pal-Gastine not being,
sufficiently solid for this purpose. To avoid this drawback, Vermorel
has improved this pal and has invented the pal- Excelsior, which
differs from the foregoing by the fact that the valve is placed in a
lateral tube by which it is possible to have a much stronger perforating
tube. To regulate the quantity of carbon disulphide it suflices to give
a longer or shorter course to the piston, by intercalating washers in
the body of the pump. By this means the jja^-JSxcc/iior can be
regulated at will for an output of 5, 6, 7, 8, 9, and 10 grammes of carbon
disulphide at each injection. In actual sulphurization the pal is
seized by the two handles, then sunk in the ground by the help of

DISINFECTION BY CAEBON BISULPHIDE.

63

the pedal. By pressing on the rod of the piston the carbon disulphide
is projected into the soil, then the rod re-ascends of its own accord,
under the action of an inside spring. The pal is withdrawn from the
soil, and an assistant rapidly fills up the hole with a wooden rod
ending in a rounded piece of iron or lead. To hasten the operation,
which ought to be done very rapidly, it is well to employ three work-
men, and to possess two pals. A workman fills the container of the
pal by a tap fixed on the barrel, whilst the second injects, and the
third plugs the holes. In vineyards arranged for the work the pal is
replaced by sulphide wagons or traction injectors, which do the work
much more rapidly, and thus economize manual labour. The mechan-
ism of these machines comprises a roll, acting like a pump, which
after drawing the carbon disulphide into a reservoir, spreads it
into a hollow traced by the sock of a plough, which immediately
covers the hollow which has just been excavated. Amongst the
different systems of instiruments the most common are those of Gastine
of Marseilles, Vernetteand Satui-nin of Beziers, and Cobal of Toulouse.

Fig. 5. — Pal-Excelsior.

In other appliances the organs of distribution of the carbon disulphide
are fixed to some sort of plough. Such are the Salvator vitis of
Audebert of Bordeaux and the Sulfureur Uhournais of Defontaine of
Izou. These machines are blamed for not depositing the sulphide
deep enough in the soil. To secure a good distribution of the carbon
disulphide through the layer to be disinfected, recourse is often had to
1 per cent aqueous solutions. At that strength the carbon disulphide
is not injurious to the plant, but perfectly capable of killing subter-
rannean parasites.

Disinfection in Closed Spaces. — It is used in granaries where
food-stuffs are stored. It suffices in that case to spread on the floor a
certain dose of carbon disulphide, after having closed all the vents in
the place. A toxic atmosphere must contain 0*5 per cent of carbon
disulphide. When it is required to disinfect a small quantity of corn,
it suffices to enclose the grain in a cask containing 0-5 per cent of
sulphide, and to keep the cask hermetically closed for twenty-four
hours. The grain sometimes retains a bitter taste after this treatment,
but this is removed by stirring the grain with a shovel, or by passing
it through the fanners. What is important to be pointed out is, that
the grain suffers no alteration and retains its germinative and ali-
mentary faculty. Carbon disulphide therefore presents real advantages

64 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

over sulphurous acid employed in like conditions, the latter having
the drawback, according to Balland, of removing from the gluten the
special qualities which enable it to be used in bread-making.

Destruction of Aerial Parasites. — When the plant attacked is of
no great height it is covered with a tent of imper ueable oil- cloth, or
by a zinc bell, or better still, by half a barrel (petroleum), as is done
in the treatment of vines by sulphurous acid. By this means an
atmosphere containing vapours of carbon disulphide can be created
around the tree, capable of rapidly destroying the parasites without
injuring the plant, whilst, according to Eitter and Moritz, the
phylloxera under its gallicole form and its winter egg, is killed in half
an hour at a temperature of SO^-SO" C. (68°-86° F.) in an atmosphere
containing a sufficient dose of sulphide. The vine supports without
suffering the action of this gas for twelve hours at 20° C. (68° F.).
It is, however, to be observed that the longer the duration of the
treatment, and the higher the temperature, the greater is the action
of the sulphide on the plant. The dose of sulphide to use ought never
to be greater than 0"5 to 1 per cent. For this purpose 50-100 grammes
of sulphide per cubic metre are placed in a cloche or in a flask hooked
to a branch, or on the soil in a saucer. In hothouses the atmosphere
must not contain more than 0*5 per cent of carbon disulphide. To
destroy the larvae of xylopiiages, such as the larvae of the Saperdes,
the grubs of Cossus, and of Sesia, a poisonous atmosphere is formed
in the burrows they make in the trunks of trees. To imprison the
vapours it is necessary to close the burrows with some sort of mastic.
This treatment is in no way prejudicial to the plant. Where fumiga-
tion in an enclosed space is impracticable, recourse is had to pul-
verizations with soapy emulsions, made in the same way as those with
a petroleum basis, and containing 2 per cent of sulphide, the limit of
innocuity on the tender parts of the plant. In certain cases the in-
vaded spots are plastered with the pure sulphide by means of the brush,
and that chiefly when it is a case of the destruction of the woolly
aphis [Schizoneura lanigera). The action of the sulphide employed
in this way is not so perfect as in a hothouse, or under a cloche, its
rapid evaporation not allowing of a sufficiently long action which thus
often allows the parasite to escape death.

Use against Cryptogamic Diseases. — Dematophora necatrix,
Hartig. — Jean Dufour, Director of the Station Viticole de Lausanne,
succeeded in arresting lihizoctinia of the vine by applying carbon
disulphide at the rate of 200 grammes per square metre (say about
7 oz. per 40 inches square), after having removed the diseased roots.
According to this eminent observer carbon disulphide not only acts
by destroying the mycelium of the fungus in a great measure, but it
also imparts greater vitality to the vine. The latter, rendered more
vigorous, resists afterwards the action of the fungus which may have
escaped the destructive treatment. Oberlin and Foex believed that
the improvement in soils got by the use of the exterminating treat-
ment ag<ainst phylloxera is due chiefly to the destruction of the
mycelium of injurious fungi which intervening crops are not capable
of eliminating, because they can live if need be just as well as

CAEBON BISULPHIDE. 65

saprophytes as parasites on different plants. To disinfect a vine-
yard it is advisable to proceed as follows : After having staked out the
ground by metric divisions, two holes per metre 25-30 centimetres
(10-12 inches) in depth are made with a pal and 100 grammes
(3-^ oz.) of carbon disulphide are injected into each. In compact soils
four holes are made, each of which receives 50 grammes of sulphide.
It is always well to water the ground after this operation, so as to
maintain the carbon disulphide as long as possible in the soil. This
treatment is generally carried out in winter, and the vines are re-
planted the following spring. Carbon disulphide is not applied against
any other cryptogamic diseases, but it possesses, however, a certain
action on the spores of fungi. Dr. Delacroix in his researches on the
Fusarmm Dianthi (P. et D.) observed that the conidia are killed
after seven hours in an atmosphere saturated with carbon disulphide,
and that the chlamydospores are destroyed after twelve hours. The
spores of fungi resist the action of carbon disulphide much better
than insects, but it is not impossible that the sulphide will yet find
some applications for the destruction of certain fungi refractory to
the action of the different cryptogamic bouillies.

Use against Anguillulideae (Eelworms). — Heterodera Schachtii
(nematoide of beetroot). — Kuhn, who has principally studied this
parasite, believes that the exhaustion of the soil in beet cultivation is not
due, as is generally imagined, to the want of potash or other elements
necessary to intensive cultivation, but exclusively to the exaggerated
development of this eel. Eotations are powerless to destroy this parasite,
because it lives quite as well on other plants. Willots' experiments
with gas liquor only gave incomplete results. Carbon disulphide,
tried in the year 1875, was not recommended until 1877 by Aime
Girard, after he had discovered its surprising effects. In Germany,
Hollrung also got good results by the use of this insecticide, but
provided it was used in a large dose, that is to say, of 1"8 metric tons
per hectare (say 1584 lb. per acre) spread in the holes placed regularly
50 centimetres (20 inches) apart.

Heterodera radicicola, Greff. (root eel worm). — Dussuc recom-
mends for the destruction of this eelworm the cultural treatment
used against the phylloxera. The different nematoides that live on
the roots of all these plants of large scale agriculture, and which
neither deep cultivation nor rotations can destroy, contribute in great
measure to create that peculiar state of soil known as exhaustion. In
these conditions when their presence in very great number is re-
cognized in a soil, it is well to have recourse to a complete disin-
fection of the soil, using massive doses of carbon disulphide. This
treatment will maintain the fields in good condition for several years,
especially if care be taken not to convey thereon farmyard manure
liable to contain eelworms.

Use ag'ainst Insects. — Insects, the larvae of which live at the
expense of the roots, may be destroyed by carbon disulphide used in
the conditions indicated to destroy the phylloxera.

Melolontha vulgaris (cockchafer). — In carbon disulphide an in-
fallible remedy has been found for the destruction of the larvae of

5

66 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

the cockchafer, the white worm, on condition that it be appHed
at the right time and intelligently. It is even more active than
benzine, recommended under similar circumstances by Vermorel.
Falconnet and Treyre, who were the first to use this insecticide as far
back as 1883, pointed out the absolute efficiency of this treatment.
There does not exist for this particular application of carbon disulphide
precise data as to the depth to which the injection should be made.
The white worm travels, in fact, constantly in the soil ; it rises and
descends according to the hygrometric condition of the soil, and the
temperature. In winter it buries itself at a depth where it cannot be
reached by insecticides, in summer it ascends, on the contrary, into
the superficial layers where disinfection cannot reach it, the tension
of the vapour of carbon disulphide not being sufficient, and the larvae
often finding enough air to escape asphyxia. It is therefore necessary
to seize the moment when the larvge are about 30-40 centimetres (12-
16 inches) from the surface of the soil, that is to say, about the month
of October or November, when it descends, or in the month of
February, when it re-ascends into the surface layer to commence its
ravages. So that the treatment may be followed by a complete re-
sult, it is necessary that carbon disulphide invade the whole zone of
soil occupied by this dangerous larva ; the treatment ought, therefore,
to be preceded by trenching with the spade which should determine
for the moment the spot occupied by the white worm. The in-
jection is regulated in such a way that carbon disulphide is volatilized
appreciably in that zone, which will be reached by working 5 centi-
metres further down. It is useless to treat the soil during the period
of the year the perfect insects appear, and which current language
designs as beetle seasons, the laying being done in the month of June,
the white worms, which are hatched a short time afterwards, do not
yet cause appreciable damage, and moreover these young larvae reside
so near the surface soil that it would be difficult to attack them.
The treatment is put off generally until the month of February of the
second year, and the time chosen the moment the larvae appear on the
surface of the soil. The laying of the beetle, occurring only once in
three years, there is only one favourable period occurring in this inter-
val. It only lasts a few months. As the treatment costs 120 francs
per hectare, say nearly £2 per acre, the annual expense will only run
to 40 francs per hectare, say 13s. per acre. It can therefore be applied
in market garden or in nurseries without entailing great expense. It
has the advantage of killing at the same time rats, mice, moles, mole
crickets, grey worms, and all the parasites which injure our crops.
Falconnet and Treyre have found that the dose of 10 grammes per
square metre (154 grains per 40 inches square) is sufficient in orchards
to kill the lai-vae in the deep layers of the soil. Vermorel and Couanon
recommend on the contrary a stronger dose, that is to say, 20-28
grammes per square metre (| to 1 oz. per 40 inches square). To
spread this insecticide use is made of a pal-injector, which is regulated
to distribute 5 grammes (77 grains) at a time in holes placed 50 centi-
metres (20 inches) apart in every direction. But the number of holes
and the dose varies according to the nature of the soil and the kind

CARBON DISULrniDE. 67

of crop. On nurseries planted with grafts, the maximum dose is 200
kilogrammes, say 4 cwt. per hectare (176 lb. per acre) ; in these the pal
ought to be sunk 35 centimetres (say 14 inches) in the soil, so as to inject
the carbon disulphide lower than the roots, and thus to avoid contact
with the liquid sulphide. On a soil free from any crop the best moment
to treat it is likewise in the middle of the month of February, and in
general it may be said that injections ought always to be made fifteen
days before planting, provided the soil is very dry. If carbon
disulphide has to be employed in the months of May and June, whilst
the white worm exercises its ravages in the upper layer of the soil,
Vaucher advises to spread a dose of 50 grammes per square metre,
in six to eight holes of 18-20 centimetres (7-8 inches) deep. Gelatine
capsules containing 2i grammes of sulphide render good service under
these conditions. It is necessary carefully to avoid working the soil
fifteen days at least both before and after the treatment.

Eumolpus Vitis, F. (Ecrivain). — Besides the very efficacious method
which consists in shaking the branches above a special funnel, carbon
disulphide, applied as in the case of the phylloxera, is capable of giving
good results. It is applied at the rate of 200 kilogrammes per hectare.
This treatment has succeeded perfectly in Hungary (Dr. Howart and
Sajo). Its use in France has been recommended by Dussuc and
Debray, in Germany by Taschenberg.

Vespenis Xatarti. — Olivier recommends to destroy these insects
by treatment with carbon disulphide, applied in the months of
December and .January. For that purpose, two or three holes are
made 25 centimetres (10 inches) from each stock, and into each hole
7 grammes {^ oz.) of carbon disulphide is poured.

Etichlora Vitis (green vine beetle). — Marchal recommends carbon
disulphide as very efficacious in destroying the larva of this beetle.

Pentodon jyunctatus (Pentodon ponctue). — Dussuc advises to de-
stroy the larva of this Coleoptera by carbon disulphide, and previously
to disinfect soils intended to receive grafted plants where this insect,
is very abundant.

Lethriis cephalotus, Fb. (big-headed lethrus). — Carbon disulphide,
it appears, gives good results in the destruction of this Coleoptera ;
however, it is advisable to make weak injections, for these must be
done vei-y near the stock, the insect being always found hidden in the
neighbourhood of the roots.

Oryctes nasicornis, L. (rhinoceros). — Carbon disulphide gets rid of
them.

Melolontha Fullo (fuller beetle) ; Rhizotrogus solstitialis (St. John
beetle). — To destroy these insects in infested regions the sulphide
should be applied before planting.

LarvcB of the Elaterides (wire worm). — A great number may be
destroyed in infested fields by laying down small pieces of apple as
bait, which as soon as invaded are collected. But complete destruc-
tion is only possible with carbon disulphide, which, in the different
tests made, has always given good results. Tax'gioni Tozetti has used
the sulphide with a dose of 300-400 kilogi-ammes per hectare (264-352
lb. per acre), or even at a dose of 100 kilogrammes per hectare (88 lb.

68 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

per acre) in emulsion with 100 kilogrammes of 4 per cent caustic
potash and 15 kilogrammes (13-2 lb. per acre) fish oil. The result
is not perfect, except after having renewed the treatment, the success
of the first injections only being momentary.

Brocchi, as well as Mohr, have obtained excellent results against
Agriotes sputator by using capsules containing carbon disulphide. The
larvae of the Elaterides are very hardy, and as they live mostly in the
upper layers it is advisable to make holes 20 centimetres (7*8 inches
deep) and run in a dose of 50 grammes of sulphide per metre, say 775
grains per 140 inches square. It would be advisable to roll the ground
before treatment to consolidate it and prevent the sulphide from
evaporating too rapidly. Amongst the weevils there are several which
can be destroyed by carbon disulphide.

Peritelus griseus ; Othiorhynchus sulcatus, Fb. (black vine weevil).
— Muller advises to make three or four holes per square metre round
the tree and to distribute therein by the pal-injector a total dose of 25
grammes of carbon disulphide. Insects hidden underground should be
exterminated at the end of May, and the larvae during summer.

OthiorhyncJncs ligustici, L. (Liveche's weevil). — Girard, Vergnete,
Lamothe, and Brocchi have shown that treatment with carbon
disulphide is most efficacious. 0. raiicus, Fb., and 0. picipes, Fb. (clay-
coloured weevil), both injurious to fruit trees and vines, may be treated
in the same way.

Bruchus Pisi, L. (pea-beetle). — This weevil passes its entire
■evolution on the pea. Peas intended for sowing should be disinfected.
Eeh has observed that the treatment by carbon disulphide was in this
case as eflicacious as hot water. It suffices to treat peas for twenty-
four hours in a closed vessel and to aerate them afterwards. This
same process is applied to Bruchus rufimans, Schonh. (haricot-weevil) ;
to Bruchus granarius, Payk f bean- beetle) ; Calandra granaria, L.
(calender or wheat- weevil) ; Calandra OryscB, L. (rice calender), and
Anobium jmniceum (maize -weevil). The larvae of these weevils live
inside the grain and cause great ravages in granaries. The following
processes have been used to exterminate them. Spread on the floor
of the infected granary 1 litre of carbon disulphide (35'2 fl. oz.), pile
the grain in a heap on the drenched space, and cover it with a tent or
a cloth. The grain may also be spread in a closed chamber, in a layer
20-30 centimetres deep and 1-2 litres of sulphide per ton of grain to be
disinfected uniformly distributed thereon. The whole is covered with
sacks, and the sulphide allowed to act for twenty-four to thirty-six
hours. This method of disinfection has the drawback of being attended
by certain fire risks, and that is why it is done far from dwellings. In
that case a cask is used, which is filled with grain, then the carbon
disulphide is run in at the rate of 500 gi'ammes (I'l lb.) per 100 kilo-
grammes (220 lb. of wheat). The cask must be closed, with its lid, so
as to roll it, first, shortly after closing and then a second time, twelve
to twenty-four hours afterwards. Nothing remains to be done but to
empty the grain, which is perfectly disinfected (Pabst and Hollrung).
The bad taste imparted to the grain does not last long, and it rapidly
disappears if shovelled a few times, or if passed thi-ough the fanners.

CARBON BISULPHIDE. 69

Hypera polygoni. — The larvae of this weevil attaches itself to the
stem of the poppy and forms a disease of that plant. Sorauer advises
the application to the stems of a soap emulsion, containing a little
carbon disulphide.

Saperda Carcharias, L. (large poplar longicorn). — It is i-ecom-
mended to inject carbon disulphide into the burrows occupied by the
larvae and to stop the holes at the base of the trunk with mastic. The
larvae of Lueanus cervus (Cerf volant) in old oaks are destroyed in the
same way, as well as numerous capricorns, of which the following are
the principal : —

Cerambyx heros, F. (great capricorn injurious to oaks) ; Ceramhyx
dilatatus, Eatzeb. (maple capricorn) ; Galeruca calmariensis (elm
galeruca). — The larvse pass through their first stage of metamorphosis
underground, in the neighbourhood of the trees, in the end of July,
and the perfect insects pass the winter in the same spot. It is
therefore at these two periods that it is possible to destroy them by
injecting into the soil 50 gi'ammes of carbon disulphide per square
metre, spread all round the stock, in eight holes onl)' 20 centimetres
(7"8 inches) deep. Watering of the soil before the application facilitates
the action of the sulphide on these insects lodged in the upper part
of the soil. Carbon disulphide has also been employed with equal
success against : —

Gryllotalpa vulgaris (Courtiliere, Taupe, Grillon), (mole-cricket,
churr-worm, eve churr, or earth crab). — Soils are rendered immune
for ten years by carbon disulphide on condition, however, that there
is co-operation between the different proprietors of the neighbouring
cultivated fields. The total expense per hectare rises to 180-200
fi'ancs for ten years, say 20 francs (16s.) per hectare per annum (say
6s. 4-8d. per acre), which is trifling. The sulphide is employed at the
rate of 40 grammes per square metre if the soil is compact, and at
the rate of 30 grammes only when the soil is light. The latter type
of soil is always preferred by the insect. In Italy, near Nola, where
mole-crickets have caused serious ravages for twenty yeai's, carbon
disulphide has been used over a great area, and has been recognized
as an infallible insecticide. Janin advises gardeners to use capsules
containing 3 gi'ammes of sulphide, and to deposit them here and there
in their burrows, and afterwards to water the soil. It is preferable to
make injections in the burrows, by making numerous holes, in the
spring.

Tipida oleracea (daddy longlegs), Tijmla 2^'^o,i&nsis (the spotted
garden gnat). — Mai-echal got good results by injecting carbon disul-
phide. To free a lawn from the larvae of these insects 20 grammes of
carbon disulphide should be spread in three holes per square metre,
the grass trenched after a few days and sown with the seed. There
may be destroyed in the same way the Tipula crocata and the Tipula
vielanocera, injurious to young plantations of Abies balsamea and of
Pinus sylvestris.

Spilograplia cerasi, F. (cherry spilograph, cherry fly). — Besides
the process which consists in collecting all the wormy cherries,
Taschenberg recommends as an excellent means of destruction, to bore

70 IXSECTICIDES, FUNGICIDES, AND WEED KILLERS.

numerous holes, in the month of July, of 10 centimetres (4 inches)
in depth, around the cherry trees and to run in a little carbon disul-
phide, to stop them afterwards, and water the soil. The soil under
the tree may also be watered with a solution containing 1 part in
1000 of cai'bon disulphide.

Vespa vulgaris (common wasp), Vespa crabo. — To destroy these
hymenoptera 20 grammes, say f oz. by weight, of carbon disulphide
is run into their nest during the night, and the orifice plugged.

Agrotis segetum, W. V. (common dart moth). — The grub of this
moth is known as the grey worm. Coste-Floret has observed that
the French vine, which regularly undergoes antiphylloxeric treat-
ment, does not suffer from grey worm, whilst American vines, which
are not treated with carbon disulphide, suffer much. The grubs of
the following insects may also be combated by carbon disulphide,
using the same process : —

Agrotis exclamationis (hart and dart moth), Agrotis Tritici, Agrotis
Bavida, W. V., Agrotis nigricans, L., and Agrotis corticea, all injurious
to crops. Agrotis vestigialis, Hfu., injurious to pines and larches.
Hespialis Humuli, L. (the otter moth), the larvae of which gnaws the
large roots of the hop from the month of August to the month of April.

Cossus ligniperda, L. (goat moth). — Taschenberg recommends to
make injections of carbon disulphide in the burrows as soon as the
grub appears, and to close the orifices with mastic ; the grub is
asphyxiated without injuring the tree. Trees attacked interiorly by
the grub of the following butterflies may be treated similarly : —

Zeuzera ^^sculi (leopard moth of chestnut), Sesia apiformis, L.,
Hornet (wood leopard moth).

Amongst the Microlepidoptera which may be combated by carbon
disulphide, those injurious to stored grain may be quoted, such as : —

Sitotraga Cereallela, A. (grain alucite) ; Tinea granella (grain
mite) ; Asopia farinalis (flour mite). — They are destroyed like the
wheat weevil.

Cemiostoma SciteUa, Zell. — Sirodot recommends to combat this
grub and exterminate the butterfly to hook on to the tree a flask
containing carbon disulphide. All the Lepidoptera, of which the larvae
are minute, may be destroyed in the same way, such as Elachista,
Nepticula, Incurvaria, Cohopliora, Cosmopterix, Gracilaria, etc.

Plant Lice. — According to a report of the Minister of Agriculture
of the United States, published in 1895, all root lice, of which the
phylloxera is the best known, may be destroyed by carbon disulphide
injected into the soil, around the infected plant. Amongst these lice,
which live on roots, the following are the most important : Phylloxera,
Fonsc. ; Hchizoneura, Hart. ; Penij)]iig7ts, Hart. ; Tychea, Koch. ;
Travia, Heyd. ; EJiizobins, Burm. These lice, which, for the most
part, do not live exclusively on the roots, become especially injurious
because they wither the latter up by their perpetual suction, and so
kill the tree.

PJiylloxera vastatrix (phylloxera of the vine). — To destroy the
phylloxera, either aerial or underground disinfection is used. The
aerial disinfection of the winter egg of the phylloxera, under the form

CARBON DISULPHIDE. 71

of " gallicole," is done by methods described further on. However,
it may be carried out b)' means of carbon disulphide on grafts and
buds from a contaminated region, because a sojourn of an hour in an
atmosphere saturated with the vapour of this insecticide is sufficient
to kill the phylloxera and its eggs. Buds and plants may be so dis- '
infected.

Underground Disinfection. — This method of disinfection is the
most important. It is, in fact, because it withers the roots of the
vine that the phylloxera kills this plant and destroys entire vineyards.
Amongst the numerous insecticides, proposed for the destruction of
the phylloxera, carbon disulphide, and its derivatives, the sulpho-
carbonates, have alone given good results. According to the district,
and also as circumstances may require, two distinct treatments may
be applied : —

1. The extermination process, destroying all the insects of the vine
and the plant itself.

2. The cropping process, only destroying a portion of the insects,
and not injuring the vine, so that the latter, in spite of its parasites,
may produce sufficient crops.

Extermination Treatment. — In districts far from invaded centres,
where an invasion of the phylloxera is in its initial stage and shows
itself in certain isolated spots, which threaten a whole vineyard, there
must be no hesitation at the right moment to adopt the extermination
treatment, which is capable of radically arresting the propagation of
the insect, but it is necessary to sacrifice, at the same time, the
attacked vines. This process, which is less and less used, since by
the cropping treatment the plant may be maintained in a passable
state of resistance, was in use, and even obligatory, in the borders of
France, Switzerland, and Alsace-Lorraine, the vineyards of which,
constantl}' threatened by destruction, were only preserved by these
drastic measures. The extermination treatment is as follows : As
soon as the phylloxera makes its appearance in a vineyard, the vine
stems are cut down level with the ground, over the whole surface
infected ; these stems are burned on the spot. Before pulling up the
stocks, holes 60 centimetres (24 inches) deep, 50 centimetres (20
inches) apart, in all directions, are made in the soil, and 50-100 cubic
centimetres (lf-34- fl. oz.) of carbon disulphide poured into each
hole, which is plugged. If the soil be dry it is slightly watered, so that
there forms on the surface a slight crust, which prevents the too rapid
evaporation of the insecticide into the air. Three years after this dis-
infection all the stocks with their roots are pulled up and burned on
the spot, after drenching them with tar. Fifteen days afterwards two
new applications are made with weaker doses ; 50 cubic centimetres
per hole then suffice. In x\lsace-Lorraine, where, this treatment was
prescribed, it was forbidden to replant the vine for ten years. Since
the researches of Oberlin and Dufour have cleared the minds of the
authorities, the vine can be replanted the spring following the treat-
ment. These vines are, moreover, of extraordinary vigour, and yield
from the fourth year a better crop than that obtained in untreated
vineyards. If the extinction treatment was capable of retarding the

72 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

phylloxeric invasion for several years, it has never, on the other hand,
prevented subsequent invasions, so that this very costly treatment
has been abandoned.

Cropping Treatment. — Instead of destroying the vine by massive
doses of 2^ tons to 3 tons of carbon disulphide per hectare (1 ton to
24 cwt. per acre), its sanitary condition is to-day improved by an
annual disinfection of 200-250 kilogrammes per hectare (176-220 lb.
per acre), accompanied by more abundant manuring ; instead of losing
the precious time I'equired to form a vineyard, the attacked vines are
maintained in a good state of production. There are some that stand
this treatment for thirty years, and are in perfect health. In Mouille-
fert's opinion, neither the cropping treatment, even in big doses, nor the
submersion, nor other methods, give anything but incomplete results.
Some insects always escape destruction because the distribution of a
gas or a liquid through a layer of soil of unequal composition can
never be perfect. If this treatment be not annual, it will be of no use,
but annual treatment accomplishes perfectly the end in view, for it
then annually frees the vine from the greater number of its parasites,
and enables it each year to regenerate its atrophied roots, and to live,
therefore, with its parasite without suffering too much from it. Every
rational observer must therefore acknowledge that if this process be
not perfect, and that plants grafted on vines immune to this insect have
been the safeguard of the vine-grower, carbon disulphide has rendered
great service by preserving the greater part of the French vines in a
good state of production. The pure sulphide, or its solution, in water
may be used.

Use of Pure Carbon Disulphide. — So that the treatment with
carbon disulphide may give the desired result, it must be used accord-
ing to the rules established by numerous experiments, and formulated
by our learned professors. The accidents and mishaps that befel
certain vine-growers were due to working during bad periods, and on
unfit soil. Dr. Colas formulated in 1877 the rules for the use of
carbon disulphide : (1) Treat the phylloxera as soon as it appears.
(2) Treat the whole of the vines, and not the spots only. (3) Apply
carbon disulphide in doses of 18-20 grammes per square metre, say | of
an oz. (wt.) per square yard. (4) Make injections between the stocks
so as to place each of them between four holes, avoiding touching the
roots with the pal. (5) Sink the pal only 15-20 centimetres (6-8 inches)
deep. (6) Take care to plug the holes immediately after the operation.
(7) Always take care to let heavy soils, which retain water a long time,
drain after heavy rains and thaws. (8) Avoid treatment at the two
seasons of the year when the sap begins to move. (9) Cultivate and
manure the vines treated in a suitable manner. (10) Avoid treatment
when frost is feared.

These rules have not been appreciably altered up to now. To
create around the vine an atmosphere uniformly charged with vapours
of carbon disulphide, uniform doses must be made to penetrate into the
soil at equal distances. An arrangement of holes as uniform as possible
must be chosen, and the treatment applied uniformly over all the ex-
tent of ground to be disinfected. Not less than 20,000 holes per hectare

CAKBON BISULPHIDE, 73

(say 8000 holes per acre) must ever be made, nor less than 40,000
(16,000 per acre) in land only slightly permeable. A distance of
30-40 centimetres (12-16 inches) is generally kept from the foot of the
vine, so as to avoid wounding the large roots. In many cases, how-
ever, deep injections can be made at 20 centimetres from the stock. "
The amount of sulphide injected per hole depends on the number of
injections per square metre. At Libourne, for example, only 12
gi-ammes is injected per hole, say 160 kilogrammes (352 lb.) per
hectare(141 lb. per acre), instead of the dose of 200 kilogrammes (440 lb.)
per hectare (176 lb. per acre) usually emploj^ed in the Ehone, where
the vines produce in consequence of this methodical treatment as
beautiful crops as before the invasion of the phylloxera. The dose
to use depends, moreover, on the depth of soil and the age of the vine.
If it be desired, like Monestier, Lautaud, and d'Ortomann, to bathe all
the root system in a toxic atmosphere, three holes must be made 1*2
metre (4 feet) deep, the roots of certain vines being more than 1 metre
(3 '28 feet) in length. Cabanel and Degrully, however, advise not to
go beyond a depth of 50 centimetres (say 20 inches). In compact
soils 20 centimetres (7'8 inches) is enough. When holes are made in
the immediate neighbourhood of the stock as the tendency is now, a
depth of 8-10 centimetres (3-4 inches) is not exceeded. The greater
number of vineyards is treated by the pal-injector. In large vineyards,
however, the plough is employed as follows : In vineyards where the
lines are a metre (3*28 feet) apart, two turns of the plough are given
between the lines. Each line of treatment is 25 centimetres (10 inches)
from each row of stocks. In the case of vines planted at greater intervals
care is taken to maintain the distance of 25 centimetres from the stocks
for the first line, the others are 50-60 centimetres (20-24 inches) from
each other, but it is best not to approach the rows of vines too closely,
for at 5-10 centimetres (2-4 inches) they suffer from the injections.
Sulphuretting ploughs were introduced with great enthusiasm, but they
did not give the results anticipated. That is, because in spite of their
ingenious arrangement, the carbon disulphide cannot be introduced to
any depth, \^nthout meeting and wounding the roots. The great ad-
vantage of these improved instruments consists in the fact that a man
and a horse can treat ^ hectare (1;^ acre) with them in a day. The
work, moreover, is very uniform as regards distribution and dose, especi-
ally with intermittent jet drainers. The latter, especially, have the
great advantage of greatly facilitating the diffusion of carbon disulphide
which is projected with force, and which is divided almost instantane-
ously. The efficiency of the treatment by carbon disulphide depends
especially on the nature of the soil, and Degrully is of opinion that there
exists for each soil a propitious moment favourable to the uniform
distribution of carbon disulphide ; this moment should be observed and
chosen by the vine-grower. In permeable or sandy soil, cracked or
too dry, the carbon disulphide will escape without producing its etfect.
But in compact moist or clay soils it does not spread enough and
remains concentrated around the holes, thus destroying a portion of
the roots in their neighbourhood and remaining without effect on a
great part of the soil affected. The treatment must therefore be de-

74 INSECTICIDES, FUNGICIDES, AND WEED. KILLERS.

ferred until the soil is neither too moist nor too cracked by the
heat.

Although the painstaking observer will always be capable of utilizing
the sulphide against the phylloxera in no matter what ground, its use
is exclusively recommended in medium ground, neither too light nor
too heavy, neither too moist nor too dry. Just as the treatment should
never be applied after tillage, which bj' lightening the soil lets the
sulphide evaporate too easily, it is necessary to wait fifteen days before
trenching or > working. The most favourable time for treatment de-
pends, moreover, on the condition of the vine ; although the latter does
not suffer from this treatment when the dose is small, yet it is advisable
to choose the time when the sap is at rest. October or November is
preferably chosen for making injections ; February and March are
quite as favourable. So that the action of the sulphide be complete,
the vine must be allowed to reconstitute its root system by giving it
abundant manure, especially mineral. When the vine has been sul-
phuretted annually from the time of the invasion, it need not receive
further care than what it usually gets.

Use of Carbon Disulphide Dissolved in Water. — The carbon
disulphide used in the beginning of the phylloxeric invasion, having
too often caused the death of the vine, it was thought that by dissolv-
ing the sulphide in water it would be less hurtful. The new method
was proposed by Cauvy in 1875, and recommended in 1882 by
Kommier, but it was not rendered practical until after the researches
of Fafeur, C. Benoit, and Duponchel. A saturated solution, i.e. con-
taining 0'5-l'2 per cent of carbon disulphide, is perfectly capable
of combating the phylloxera ; it kills it in twenty- four hours. The
advantages of this method are that it is perfectly harmless to the vine
even when it is in full vegetation, and that it can secure a uniform
distribution in the soil. According to Degrully, the action of these
solutions is the more perfect the more permeable the soil. Under this
form the sulphide acts quite as well as potassium sulphocarbonate and
has the advantage of being much cheaper ; 200 lb. of sulphocarbonate
employed in the same conditions as 10 gallons of carbon disulphide,
in 1 per cent solution, do not give so good a result. To prepare
a solution of sulphide, Fafeur freres have designed an apparatus
capable of spreading water on a layer of carbon disulphide, in
a closed reservoir. A current of water flows through a pipe of suitable
dimension drawn out to a point. The pressure obtained by the draw-
ing out and the speed of the current is exerted on the upper part of a
receiver full of water and sulphide which, ov,'ing to its density, always
occupies the bottom of ihe receiver. This pressure is transmitted to
the receiver by two orifices. The solution is thus produced under
pressure in a closed vessel by the junction in a pipe of two jets of
sulphide and of water, the intensities of which are always proportional
to each other. By opening the gauge taps the dose is regulated from
0"5-l'2 per cent. The sulphuretted water is carried by buckets or
a long watering pipe into small holes specially dug round the stocks.
These holes should be well made, horizontal, and separated from each
other by mounds of earth so that the liquid is spread uniformly in the

CARBON DISrLPHIDE. 75

soil. Working on a large scaFe steam pumps carry the sulphuretted
water several kilometres (kilometre = 0"62o mile) bj- means of a
galvanized iron pipe. The average amount of sulphuretted water for
each stock is 20 litres (4"4 gallons), and the solution contains 0*5 per
cent of sulphide in summer and 0"7-l per cent in winter. The soil
should be returned to its place as soon as possible after treatment.

Insecticide Irrigations. — These examined and recommended by
Duponchel represent the most improved and rational system. Under-
ground irrigation, already very efficient in itself especially when manure
is added to the water, appears to be a method of treatment that can
be usefully applied in the treatment of the vine attacked by the
phylloxera. But although the ordinary treatment enables the state of
diseased vines to be improved, it could not in itself constitute a sufficient
remedy to kill the phylloxera and annul the disastrous effects of that
insect. Insecticide irrigations have a very salutary effect on vines and
fulfil the end in view. Carbon disulphide cannot, in fact, suffice by
itself alone to re-establish the health of a diseased vine during drought,
or when root growth is stopped. To attain this salutary effect it is
necessary to follow up the injections of sulphide, which in destroying
the phylloxera suppress the evil by an underground irrigation which
causes the effects to disappear by fortifying the roots and giving new
vigour to the vine. It is better to combine the two treatments in a
single one and to apply simultaneously to the plant, along with the
water carbon disulphide and the necessary manures. This method of
diffusing the insecticide throughout the whole depth of the soil, in a
dose which it is known cannot injure the plant, produces an excellent
effect. The irrigations ought to penetrate 20-2-i inches into the soil.
They require 1000 cubic metres of water per hectare, say 100 kilo-
grammes (88 lb. per acre) of sulphide, which represents 30 cubic
metres (6600 gallons) of sulphide vapour (2640 gallons per acre). A
stronger dose would injure the vine, especially during the epoch of vegeta-
tion, which lasts eight months. Insecticide irrigation is differentiated
from the sulphide treatment by the fact that the first can be applied in
the spring, in summer, and in autumn without prejudice to the plant,
whilst the latter can only be done during the repose of vegetation.
The irrigation water is brought to the culminating point of the vine-
yard to be treated. At this point it is mixed with the carbon disul-
phide in a tank, called the bubbling tank, and arranged so that the
water charges itself with carbon disulphide without being able to carrv
away with it what has not been dissolved. The same bubbling
apparatus used to dissolve the sulphide may serve for dissolving
the manures, so that the water entrains them and distributes them
throughout the whole extent of the diseased vineyard. To produce
good results the irrigation should be underground and the surface of
the soil should be maintained constantly dry and friable by tillage or
by hand hoeing, carried out after watering, and renewed each time
that rain has strongly packed the soil. To secure good underground
distribution it is necessary to lighten the soil by tillage and to open
around each stock a small ordinary stripping basin. These basins
are connected with each other so that they can be filled in succession.

76 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

If the tanks have only the slight slope required to ensure the flow
of water without a gush, the water introduced into the basins will
filter into the soil without moistening the surface layer. As soon as
the liquid is completely imbibed, the holes are filled with dry earth
and the soil is soon afterwards tilled and hoed. The large quantity of
water which these irrigations require renders the treatment almost
impossible. But when a spring with an output of a litre a second
(13*2 gallons a minute) is available the quantity of water produced
suffices to irrigate 10 hectares (25 acres). Underground insecticide
irrigations, although useful in all cases, are particularly favourable in
the hot countries of the South of France, where it is necessary to
ameliorate the hygienic conditions of the vine by moisture to enable
it to reconstitute its root system after being freed from the insect
which caused the disease.

Schizoneura lanigera, Hausm. (woolly aphis). — The disinfection of
the branches, as is done by applying various insecticides, is not
enough, for there exist underground hot-beds of infection which re-
infect the crown of the tree. Carbon disulphide, used in injections
round the plant, forms an excellent means of destroying the aphis
living on the roots. Taschenberg and Goethe have recommended the
use of carbon disulphide to destroy the colonies existing above ground.
They advise for this purpose the use of a stick, to the extremity of
which a lump of cotton-waste dipped in carbon disulphide is fixed.
The woolly aphis can thus be destroyed at all seasons without injuring
the apples. To get a good result the colonies must not be overlooked,
and to recommence the treatment some time after the first. Targioni
and Sorauer recommend soap emulsions for the same object, the first
a 2 per cent carbon disulphide one, and the second a 4 per cent one.
Gold's liquor, recommended for the destruction of the w^oolly aphis,
consists of 20 grammes of [spirits of ?] turpentine, 20 grammes of
carbon disulphide, and 60 grammes of curdled milk. Amongst the
underground ground lice that often occasion great damage are the —

Schizoneura Grossjdarice, Schule, which sucks the roots of the
gooseberry.

Aphis Persicce nigcr (the peach tree aphis). — This aphis causes
ravages in peach orchards in America.

Tychea Phaseoll, Pass. — The presence of which, on the roots of
haricots, cabbages, and potatoes, sometimes causes them to perish.
All these insects may be combated like the phylloxera. The lice
which sometimes damage certain plants are successfully combated
when it is possible to cover the plant with an awning or a cloche (bell-
shaped vessel) under which a few grammes of carbon disulphide are
laid. According to Smith all the lice are killed in an hour. Even
after twenty-four hours' treatment at the ordinary temperature the
plant does not suffer. Soap emulsions, 2-4 per cent, have likewise
been applied in a general way, but these latter, which sometimes
succeed perfectly, may completely roast the leaves, chiefly those that
have been wounded.

Coccides (cochineals, kerraes). — In a general way the Coccides resist
carhon disulphide to a greater extent than the A])Jiides, but they do not

CAEBON BISULPHIDE. 77

resist a sulphuretted atmosphere. By destroying the cochineal the
fumagine (smut of fruit trees) is arrested.

Coccus Vitis, L., syn. Pulvinaria Vitis (red cochineal of the vine) ;
Dactijlopius Vitis (white cochineal of the vine). — Targioni-Tozzetti and.
Pastx'e recommend carbon disulphide emulsions.

Diaspis pentagona, Targ.-Tozz. (mulberry kermes). — Franceschini
recommends for the disinfection of buds to place the branches before
detaching them from the tree in an atmosphere of carbon disulphide.
With this end in view, the end of the branch is placed in a tight
cylinder, where it is left some hours in contact with a toxic atmo-
sphere. This treatment whilst disinfecting the buds is not injurious
to them.

Orange scale insects : (1) Aspidiotus Limoni, Sign ; (2) Mytilaspis
fiavescenSyTsbvg.-Tozz. ; (3) Chrysomphalus minor. — The first, especially
injurious, in Italy induces the fumagine, the last two, imported from
America, dot the organs attacked with small yellow spots. Hoffmann
recommends spraying with carbon disulphide emulsions, containing
2 per cent of soap and 2 per cent of sulphide. Belle advises the
destruction of these parasites in greenhouses and pot plants by
covering the latter with an awning, and producing a sulphuretted
atmosphere, 120 grammes of sulphide sufficing per cubic metre.

Mammals. — The rodents which cause damage, such as the mouse,
field mouse, ground squirrel, rat, and even the mole, may be destroyed
by pouring carbon disulphide into their burrows and stopping the
orifices of their nests. It takes 20 grammes (say f oz.) for the Mus
sylvaticus, L., Borghi ; 10 grammes (say J oz.) for the ground squirrel
{Spermophihis citillus, Bajor) ; for rats 60 grammes (say 2 oz.) are
necessary. The most radical method consists in steeping rags in
carbon disulphide and in inserting them deeply into their holes, which
are afterwards plugged with plaster, mortar, or a plug of hay coated
with potters' clay.

CHAPTEK IV.

SULPHUKOaS ACID— SULPHURIC ACID (OIL OF VITRIOL)— CHLORINE
—HYDROCHLORIC ACID— NITRIC ACID.

6. Sulphurous Acid, SOo. — Preparation. — This gas is prepared
on the large scale by the oxidation of sulphur. When sulphur is
inflamed in contact with air this product burns and is converted into
sulphurous acid. Pyrites, or sulphide of iron, which is roasted at a
great heat, may also be used to obtain this same acid. That is the
process most usually employed. The gas is led into a gasometer,
where it is liquefied by cooling.

Properties. — Sulphurous acid is colourless and very fluid. It boils
at 8° C. below zero; its density is 1'45. Sulphurous acid is not com-
bustible. Its use is, therefore, attended with no risk of fire. Eespired
in large quantities it induces suffocation, but in small quantities it
is not injurious to man.

Action of Sulphurous Acid on Plants. — x\ll plants, with-
out exception, suffer in an atmosphere of SO.,. The leaves absorb
this gas, very much attracted by water, and hydrate it. Almost all
the sulphurous acid is retained there, and they are the first to suffer.
A very small quantity then passes into the wood of the plant. Under
the influence of the solar radiation the hydrated sulphurous acid is
ti'ansformed into sulphuric acid, with liberation of sulphur, according
to Loew's equation : —

3H.,S03 = 2H2SO, -H S + H,0
Sulphurous = Sulphuric Sul- Water
acid acid phur

The numerous analyses made on dead plants, after the absorption of
sulphurous acid, all, in fact, give abnormal quantities of sulphuric
acid.

Wislizenus, who widened the question by very conclusive experi-
ments, believes that sulphurous acid, absorbed by the plant, has no in-
jurious action on the latter, except the plant be full in the light, and
especially in full sunlight ; in darkness the action is nil, although there
is absorption of the gas, and in winter the action is very attenuated.
According to the experiments, an atmosphere containing a proportion of
i^X)lx)TiX) of ^^^ volume of sulphurous acid kills fir-t)-ees (sajnns) in about
four weeks if they are in contact with this air in full daylight, but these
same firs do not appear to suffer if the experiment be repeated in
darkness, even if the atmosphere contain .-,00 Wo ^^ sulphurous acid.
It is thus evident that sulphurous acid is only converted into sulphurie

(78) ^

SULPHUEOUS ACID, 79

acid under the action of light, and it is the latter acid which is
injurious to plants. Agreeing with Von Heine, Wislizenus concludes
that sulphuric acid destroys the chlorophyll of the plant, and that it thus
acts in a manner unfavourable to assimilation. Sulphuric acid dries
the cell-walls and renders them impermeable. Only the tissues in
contact with the fibro-vascular bundles remain fresh and green, whilst
the others wither, brown, or bleach. In that lies the characteristic
symptom of these poisonings. According to Von Heine, the trans-
piration of the poisoned leaves, the cell-walls of which have become
impermeable, is less than that of healthy leaves. As the activity of
transpiration expresses the production of matter, the leaf assimilates
less, the plant remains stationary, and finally dies. The greater the
amount of sulphurous acid absorbed, the more intense the sun, the
greater the heat, and the drier the air, the more quickly are these
symptoms produced. All leaves, however, do not absorb the same
amount of sulphurous acid in the same atmosphere. With equal
leaf-surface, those of conifers absorb much less of this gas than those
of deciduous trees and herbaceous plants. It was believed that the
gas being absorbed by the stomata of the leaf, the quantity retained
would be proportional to their number, but experience has shown that
it is not so, for leaves absorb this gas quite as well by their upper
surface. The herbaceous plants are ranked, according to their sensi-
tiveness to sulphurous acid, between the conifers and the deciduous
trees. The leaves of the pajJtlionaceie (pea tribe), potatoes, cereals,
and meadow grass, commence to fade and lo brown at their extremities
after exposure of two hours in air containing tottoo sulphurous acid ;
in an atmosphere containing only 7^1^011 ^^ ^'^is gas desiccation
does not occur until after fifteen to twenty hours. For leaves of
deciduous trees to perish the air must contain jy^oo *o ^ojtojj of sul-
phurous acid. Conifers in general, and especially firs, do not support
air containing more than ^o^ocr ^o -jtt^oo ^^ ^^^^ S^^' especially in the
neighbourhood of factories. This small quantity of sulphurous acid
necessary to cause a pathological condition of the plant is the reason
why each factory chimney must be regarded as a perpetual hot-bed of
infection. The smoke from the combustion of coal contains on an
average 0*01 to 0*02 of sulphurous acid gas. The danger is obviated
if the smoke is sent into the air byjchimneys measuring 20 metres, say
65 feet, in height. The following, for example, shows the deterioration
undergone by a field of oats situated near a coke factory. One thou-
sand seeds of normal oats ought to weigh, on an average, 25-29
grammes ; 1000 grains in the sickly field only weighed 14-76 grammes.
Both the grain and the straw in this field were analysed, and in both
instances a large amount of sulphuric acid was found. Such damage
to crops is particularly intensified around chemical factories, chiefly
sulphuric acid factories, where pyrites is roasted, and zinc factories,
in which blende, zinc sulphide, is calcined. The deadly action of the
sulphurous acid sent into the air by these factories manifests itself at
great distances. Forests 5 kilometres, say 31 miles, away still suffer
from their proximity. A zinc works calcining 50 tons of blende dis-
engages 37,000 hectolitres (814,000 gallons) of sulphurous acid. It

80 INSECTICIDES, FUNGICIDES, AND WEED FILLERS.

will be seen that this amount of toxic gas, if not utilized, may carry
devastation to great distances. Many observations have been made
on this point, and it is found that near (such) factories the leaves of
the fir (? spruce) fall, those of the pine and larch, more resistant, only
brown at the point, and the trunk blackens; conifers, in genei-al, do
not resist long. Deciduous trees, fruit trees, among others, lose their
leaves and do not produce fruit, because the sulphurous acid sterilizes
their flowers. The cornfields are sickly, patchy ; the brown-coloured
ears contain no grain. Haricots and cabbages are spotted white and
suffer much. The dead leaves of the potato shrivel and blacken.
The meadows remain sickly and turn brown. These sickly plants
have been analysed with great care by Morren, Stockhardt, Von
Schroder, Freytag, and Konig. They found that they all contained
an abnormal dose of sulphuric acid. It is important to insist on these
facts, so as to show the injurious action of sulphurous acid on plants.
Knowing this fact it is an easier task to contradict the opinion generally
held that sulphur acts on fungi by its conversion into sulphurous acid.
If it were so our vineyards, instead of becoming more vigorous by
sulphuring, would perish, since an infinitesimal quantity of acid
suffices to roast plants, and fructification, instead of being stimulated
as is the case, would be diminished.

Action on Fungi. — It follows from observations made on plants
that those which contain chlorophyll are more sensitive to the action
of sulphurous acid than those deprived of it. Sulphurous acid cannot
therefore be used to destroy fungi.

Action on insects. — -To stifle insects the air must be saturated
with SO^. Great care must therefore be taken in using this gas so as
to avoid its deadly action on plants. The great delicacy of the opera-
tion renders it less and less popular, hence the clochage of the vine
still in use in certain districts is gradually being replaced by scalding.
The phylloxera does not persist for twenty-four hours in an atmosphere
of this gas of 1 in 60 or 1 in 100. Mouillefert tested it in the soil
against phylloxera but without result. Moisture and the nature of
the soil destroy its toxic properties.

Use in Diseases Treated by SO., in the Open Air. — Gum
Disease. — Swingle and Webber who examined the action of different
chemicals on this disease recommend to cure it, to clean the wounds
and coat them with an 18 per cent solution of SO^.

Anthonomus Piri, Boh., Anthonomus Pomorum. — These formidable
destroyers may be removed in May by SO., fumigations (Poupinel).
A dish of burning sulphur is moved about under the branches, or rags
dipped in molten sulphur and then lit. The trees should not be
fumigated with SO.^ when in blossom, as the flowers would be sterilized
even if the contact was short and the acid in very small quantity.
Such fumigations also asphyxiate the grubs injurious to fruit trees,
who know how to shelter themselves from spraying in the common
nests which they spin. The most injurious are Hyponomeuta
Malineila, Zell. (small ermine moth) and Liparis chrysorrhaea (brown
tail moth). The grubs of these butterflies are only sensitive to fumes of
SOo. Dufour proved by trial that liquid SO.2 does not act on the

SULPHUROUS ACID. 81

grubs, and that even a 20 per cent solution does not kill those of the
cochfilis.

Phylloxera vastatrix (vine phylloxera). — The phylloxera dies if ex-
posed for twenty-four hours in an atmosphere containing 1 per cent of
SOo. Hence it was thought the injection of SO., in the soil would
destroy this injurious insect. Aman Vigie recommended injections
into the soil of a mixture of sulphur and sulphur fumes from the
beginning of the phylloxera invasion. Henneguy remarked that when
this treatment was applied in summer the spread of the disease was
circumscribed, and although this process may be insufficient to free
the vine entirely from its parasite, it destroys it to such an extent as
even to allow the vine to thrive. Mouillefert examined the effect of
SO., both as gas and in solution, as well as its different salts. He
found that sulphites are quite powerless against the phylloxera. As
to gaseous SO., it has no action on insects near the surface of the soil
because this gas, with a great affinity for water, can never penetrate
deep enough into the soil.

Mus amjjhibms, L. (Eat). — M. A. ter Mer advises the use of SO.2
to kill rats. Rags are dipped in molten sulphur and petroleum, these
are inserted into the burrows and lit. It requires about ^ lb. of
sulphur per burrow. Taschenberg dissents ; he found that this method
failed, even if the gas is driven far into the burrows by means of
special bellows.

Use of SO., in Closed Spaces. — The action of S0._, is deadly to
insects when the air is saturated with it. It is used especially in
granaries against the Coleoptera and Lepidoptera injurious to the
stored grain. It has also been used on small trees which can be
covered with a tent or a cloche. The last method is used especially
to combat the cochylis of the vine.

Mycogone perniciosa (mole disease of the mushroom bed), Psalliota
campestris, L. — Constantin and Dufour found that the spores of the
Mycogone are killed by prolonged contact with SO.^. Mushrooms are
in no way injured in an atmosphere containing this gas, even if the
fumigation lasts twenty-four hours.

Hojjs. — The preservation of stored hops is not always an easy
matter. Disinfection with SO^ does not always give the result ex-
pected. Behrens found that if SOo be incapable of killing the germs
of the parasite which infest hops, it has a good effect on their quality,
v^hich it alters for the better. But it is chiefly against the invasion
of Coleoptera into granaries and on the vine that S0._, does good work.
Amongst these insects are : —

Calandra granaria (or wheat- weevil). — As a curative method
fumigation with SO., is used. The doors and windows of the granary
are closed ; sulphur is then ignited in a vessel placed on a support
above a sheet of iron ; 1500 grammes (3-3 lb.) of sulphur with 100
grammes (-22 lb.) of saltpetre, suffice to disinfect a space of 50 cubic
metres. The granary is left closed for twenty-four hours, then it is
cleansed with a 2 per cent solution of corrosive sublimate. The same
process is used to destroy Microlepidoptera, the grubs of which i-avage
grain and flour granaries.

6

82 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Sitotraga cereallela (grain mite). — So that the SO., may penetrate
well into the heap of wheat and kill all the grubs, Bernard Saint
Ubery burns the sulphvir in chafing dishes around which the grain is
piled in heaps. To destroy butterflies the process used against the
Colander gives good results. It suffices to place 1 inch to 1-^ inch of
sulphured wick on slates laid on the heap of wheat, and to set fire to
the wick. By analogy it was thought possible to destroy by the same
gas the grubs which live in flour.

Asojyia farinalis (flour mite). — The process recommended by
Debray consists in burning in closed vessels 60 grammes of sulphur
per cubic metre of flour ; the method was regarded as obnoxious, the
flour being rendered unfit for bread-making ; Balland found this flour,
whilst presenting no visible alteration, is appreciably altered in contact
with sulphurous acid. The gluten has lost the valuable properties re-
quired in baking. It is recognized, in fact, that gluten gains in value
by contact with alum, common salt, or blue vitriol, but that it cannot
stand the action of sulphurous acid, SO.,, nor sulphuric acid, SOg,
nor sulphuretted hydrogen, SH,,. To destroy the tinea of grain, SOg
must not be used, but insecticides like CSo.

Tortrix or Pyralis vitaua (pyralis of the vine). — The grubs hiber-
nating in the fissures of the bark of the vines can be killed by SO.,.
The process employed in the South of France is known by the name
of dockage, or sulphuring of the vine. After pruning the vine, each
stock is covered by a zinc cloche, or half a petroleum barrel, under which
20-25 grammes of sulphur (say | oz.) are burnt in a saucer. The
SO^ formed soon saturates the air under the cloche, and stifles the
grubs sheltered in the interstices of the bark. The operation should
not last longer than five to ten minutes, a more prolonged action having
a deadly effect on the vine. A workman provided with twenty cloches
can sulphur 1000 stocks per day. The cost is 48 francs per hectare
if brimstone be used and 75 francs if wicks be used, say 15 and 24
shillings per acre. It is thus cheaper to use brimstone. It is a very
delicate operation, which may well be replaced by scalding, but its use
is still widespread. So that it may succeed, it must not be done
when the soil is moist, for the SO.^, instead of saturating the air, would
be absorbed by the humidity in the soil. Clochage kills at the same
time as the pyralis the vine cochineal and the red spider. Eeh found
that all coccides shielded Homoptera, such as Diaspis, Aspidiotes,
Lecani'um, Ceroplastes, and cochineals, which resist all insecticide spray-
ing, may be destroyed by SOo fumes. The fruit trees are covered
with a tent, and sulphur burnt therein, observing the same precautions
as in the clochage of the vine.

7. Sulphuric Acid, H^.SO^. — Sulphuric acid is obtained by passing
a mixture of oxygen and sulphurous acid over spongy platinum or pla-
tinized asbestos, heated to between 250° C. and 500° C. (482"-932° F.).
The vapours of SO.j disengaged are led into a receiver surrounded by
a freezing mixture, where they condense. The process of manufacture
usually adopted is to oxidize sulphurous acid by nitric acid vapours and
to hydrate the vapours in lead chambers. The necessary SO3 is
obtained by "burning" iron pyrites in presence of an excess of air.

SULPHURIC ACID (OIL OF VITRIOL). 83

Natural Occurrence. — H^SO^ is widely distributed in nature as
sulphates of lime, CaSO^, of baryta, BaSO^, of soda, Na^SO^, and of
potash, K.,S04, etc. It is found in the free state in some springs in *,he
neighbourhood of volcanoes.

Properties. — The commercial acid of 66° B. (168° Tw.) is a
colourless, odorous, viscous, oily liquid of sp. gr. 1-84. When water is
mixed with the acid so much heat is developed that it may become
dangerous if the water is added to the acid. Care must therefore be
taken in diluting the acid with water to run the acid gently into the
right amount of w^ater with constant stirring. H^S04 has a great
affinity for water, and rapidly carbonizes organic matter.

Action of Sulphuric Acid on Plants. — This acid exerts a cor-
rosive action on the organs of the plants touched by it. A very small
dose of this acid (even dikite) destroys the chlorophyll and degener-
ates the cell-walls, thus givmg rise to a profound disturbance in the
life of the plant.

Transpiration is less abundant, and that of itself diminishes or even
abolishes completely the production of synthetic organic matter, the
leaves brown, wither, fall, and the grow^th of the plant is visibly ar-
rested. If the action of this acid on a plant be prolonged it soon dies,
for the acid penetrates rapidly into the interior of the trunk, and the
circulation of the sap is stopped. The same result occurs when a
plant is in contact not only with the dilute acid but also with sub-
limed sulphur w^hich contains HoSO^, and under the influence of
sunlight is converted into HoSO^ m the leaf itself.

Action of Sulphuric Acid on Fungi. — Plants not containing
chlorophyll suffer much less than green plants in contact with HoSO^.
However, owing to its hygroscopic nature, H^SO^ diluted to 0-5 per
cent exerts a corrosive action on fungi. Laboratory trials made by-
dipping the spores into a drop of H^SO^ diluted to 0'5 per cent show
that such dilute acid destroys in most instances the vitality of the-
spores, provided that its action be sufficiently prolonged. In practice-
the 0'5 per cent acid is quite inadequate to destroy the spores and
mycelium of fungi, and stronger, sometimes even the 168° Tw. acid
must be used. It will be easily seen that at that degree of concentra-
tion HgSO^ cannot be put in contact with the leaves of plants, and
that it should be limited to applications on the trunk, or to disinfect,
certain seeds ; in a wood it can only be used when there is no active
plant growth. Under such conditions, plants do not appear to suffer
from the sulphuric acid treatment. When H^SO^ is used in combina-
tion with anti-cryptogamic metallic salts, its corrosive properties be-
come valuable, because in attacking the protective membrane of the
parasites it enables the poison to reach and destroy them more readily.
In combination with green vitriol in the winter treatment of anthrac-
nose of the vine, sulphuric acid is in current use, and of great service.

Use against Parasitic Fungi. — Sulphuric acid has been recom-
mended for some years to wash seeds to free them from the spores of
different fungi which might be brought on to cultivated land. Noel
found in 1866 that steeping in the 0*5 per cent acid sufficed to free
seed-corn from anthracogenous parasites. iHe stirred up a hectolitre

84

IXSECTICIDES, FUNGICIDES, AND WEED KILLEES.

(2f bushels) in 22 gallons of 05 per cent acid, and sowed immediately
afterwards. This method has since been tested by specialists of high
reputation and found deficient. Kuhn has shown that not only was the
0"5 per cent acid an anodyne for the spores, but had the drawback of
being more injurious than sulphate of copper. The injurious action
of the acid on cereal grains does not make itself felt for some time.
Such seed-corn always retaining a little sulphuric acid cannot dry up
completely and rot. This drawback may be avoided if care be taken
to wash the seed in milk of lime immediately after steeping in the
acid. In fact, Boiret found that the spores of bunt were not com-
pletely destroyed after a twenty-four hours' steep in a 5 per cent acid,
and that a 20 per cent acid destroys the grains of wheat without killing
the germs of the disease, even if steeped six hours therein. All cereal
grains are thus sensitive to the action of H2S0^ ; however, amongst
the different species of wheat there are some which stand the acid
better than others.

TABLE XI. — Effect of Steeping Seed Wheat for Different Lengths of Time in
Dilute Sul2}htiric Acid on Germinative Capacity per cent.

Sulphuric Acid.

Duration.

Golden Drop.

Garter.

1 per cent .

24

18

2 „ „

12

40

14

2 „ „

8

—

18

5 „ „

2

90

—

5 „ „

1

92

60

Steeped in water

—

—

90

It follows that this acid does not possess the requisite properties to
replace blue vitriol in the pickling of seed corn. The only seeds that
can stand steeping in the acid are beet-seeds, which are surrounded
by a protecting sheath which enables them to stand steeping in acid
of 66" Be. (168° Tw.) without their germinative capacity being dimin-
ished. This protecting sheath acts as a shelter to the germs of fungi
and bacteria of the most diverse nature, such as Phoma tabifica, Prill,
et Delacr. ; Pythium cle Baryanum, Hesse ; Bacillus myco'ides, Bacillus
butyricus, Proteus vulgaris. As soon as the radicle and cotyledons
of the beet appear these fungi invade them, disturb the normal evolu-
tion and induce rot. Hiltner found that the 30°-35° Be. acid will
destroy the germs of all these parasites. Linhart recommends 66° Be.
(168" Tw.) acid in which the seed is steeped half an hour, then
washed ten minutes with a jet of water, then the seeds are dipped
into milk of lime, and all that now remains to be done is to wash the
seed for four hours in running water. The seeds so treated are in no
wise injured. Their germinative capacity is increased ; they spring up
more rapidly and in larger quantity, and the disease germs ai'e com-
pletely destroyed. For reference purposes a description is here given
of the researches published on the resistance of spores of different
fungi to dilute H2S0^. These laboratory trials were made by incor-

SULPHURIC ACID (OIL OF VITRIOL),

85

porating the spores of rust and of caries with a drop of dilute sul-
phuric acid, which after being a certain time in the acid w^ere sown or
examined by the microscope. In 1872 Kuhn examined the action of
sulphuric acid on the spores of the caries of wheat, and he found that
acid of the same strength is not capable of killing in the same time
the different spores of caries. A 5 per cent acid acted thus : —

TABLE XII. — Showing the Actioti of Dilute Sulphuric Acid of 0-5 2>er ceyit
Strength on the Spores of Oats and Wheat.

Duration
of Action.

Oats.

Wheat.

1 hour
6 hours
8 „
10 „

Numerous living spores
Living spores less numerous
Very few living spores
All spores killed .

Numerous living spores

In 1892 Wuthrich examined the action of different acids, com-
pared with that of metallic salts, on the spores of —

Ustilago Carbo, Tul. (smut of grain crops). — In a 0*49 per cent
sulphuric acid all spores are killed after fifteen hours' action at
20^-22'' C. An acid of 0'049 gi'eatly prevents the formation of
zoospores, whilst acid of 0-049 per cent has no longer any injurious
action on the spores themselves. In 1895 Herzberg examined the
different rusts, and submitted their spores to the action of sulphuric
acid of various strengths. The spores of Ustilago Jensenii, Eost.,the
smut of barley, were found to be the most resistant. To kill these
spores they must be steeped fifteen hours in 3 per cent acid, whilst
those of the other Ustilagince are killed in much weaker acid. More-
over, the dilute acid has not the same action on the spores of the
same species but of different ages ; the mortal dose is given in the
following table : —

TABLE XIII. — Showing the Strength per cent of Sulphuric Acid required to
Kill the Spores of Smut of Barley, Oats, and Wheat of Different Ages.

Species.

Strength of Stdphuric Acid.
Per Cent.

Old Spores.

Young Spores.

Ustilago Jensenii, Rost. .

„ Avenae, Rost.

,, perennans, Rost.

,, hordei, Bref.

,, tritici, Jens.
Circumambient temperature .

1-1-5
0-5-0-75
0-1-0-25
0O-0-7.5
0-5-0-75
1.5°-18° C.

2-4
0-5-0-75
0-25-0-5

0-.5-0-75
0-25-0-5
23° C.

Puccinia grammis (black stem rust, summer wheat mildew) ;
Puccinia Rtibigo-vera, D. C. (orange leaf rust, spring rust of corn) ;

86 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Puccinia Coronata, Corda (the crown rust of oats). — Wuthrich
made a comparative examination of these three rusts, by submitting
in turn their uredospores and their aecidiospores to the action of the
more or less dilute acid. The time of steeping was fifteen hours, and
the temperature 20°-21'' C. (68°-69"8° F.). The uredospores resisted
an acid ten times stronger than the aecidiospores ; acid of 0'0049 per cent
does not act on uredospores of 0"049 per cent ; its action begins to make
itself felt, but it is not until 4-9 per cent acid is used that all vitality is
removed from the spores. The aecidiospores are completely destroyed,
and in the same conditions, by acid of 0*49 per cent strength. The
uredospores of the rust of cereals would appear to be the spores most
resistant to the action of sulphuric acid, as they likewise are to anti-
cryptogamic salts. Hitchcock and Carleton have, however, prevented
the uredospores from germinating, by steeping them for seventeen to
nineteen hours in O'l per cent acid.

ClaviceiJS 'purpurea, Tul. (ergot of rye). — The action of the acid
on this disease was examined by Wuthrich, who found that 0'049
per cent acid attenuated the germination of the conidia, but it required
steeping for fifteen hours at 20°-21° C. (68°-69-8' F.) in an acid of 0-49
per cent to stop this germination completely. "Wuthrich, who examined
the action of the acid on the spores of PliytophtJiora and of Peronospora,
found these latter much more sensitive than those of the black and
red rust of cereals.

Phytophthora infestaus, De By. (potato disease). — Acid of 0'049 per
cent perceptibly diminishes the capacity of the conidia to form zoospores.
It may be entirely arrested by destroying the conidia, by using 0'049
per cent acid for fifteen hours at 19^-20° C. (66-2°-68° F.j.

Peronospora Viticola, De By. (vine mildew). — The conidia and the
zoospores of this parasite behave like those of the Phytophthora ; acid
of 0'049 per cent completely annihilates them in fifteen hours at 20° C.
(68'' F.). In 0"0049 per cent acid the formation of zoospores may
be restricted, and even suppressed, without the conidia being killed.
The latter then germinate and produce directly a germinative tube.
The deleterious action of sulphuric acid on the germs of mildew
has caused it to be used for the winter treatment of wine stocks.
Bouchard got good results by treating the vines in the spring after
pruning with a 10 per cent acid. During three years the vines re-
ceived no other treatment than the above, and the disease did not re-
appear. Mc Alpine came to the same conclusion, and found this
treatment always to give good results. Millardet, on the other hand,
combats this opinion, and considers treatment with sulphuric acid as
very injurious to the vine. The author nevertheless sides in his opinion
with the first observers. Acidulated solutions of green vitriol used
everywhere against anthracnosis cause no injury to the stocks.

Gloeosporium anipelopJiayuin, Sacc. (grape rot). — To combat this
disease the utility of the acid was found empirically. It is not, it
must be understood, a question of treating this disease during the
growing period, for sulphuric acid, or even the acid mixtures, would
have a deplorable action on the stocks. The acid is used exclusively
in winter to cauterize the spots hollowed out of the young wood.

SULPHURIC ACID (OIL OF VITRIOL),

87

sorts of canker produced by the anthracnose containing spores which
should be considered as hot-beds of infection. The remedy most
generally used is a 50 per cent green vitriol solution, but to intensify
its action it is associated with sulphuric acid in the proportion of 1
to 2 per cent. Fifty kilogrammes, say 1 cwt., of green vitriol are
taken, and 1 litre, say 4 lb., of sulphuric acid are poured on to it
and the whole dissolved in 100 litres (22 gallons) of hot water.
However, many vine-growers limit themselves to sulphuric acid and
regard it as sufficient to circumscribe the disease. Bouchard, Debray,
Berlese, and McAlpine are unanimous in eulogizing the good results
of this method, which according to McAlpine is of current use in
Australia. It is certain that it kills not only the spores of this dis-
ease but also those of the oidium. It is important to operate before
budding-time, so as not to injure the growth. It is necessary to im-
bibe the stems, the runners, and all the wood, and even the eyes. The
latter, owing to this treatment, blossom, it is true, some days later than
non-treated vines, but this in many cases is an advantage. The coat
may be applied with a brush or with a woollen rag.

SphcBrella Fragarm, Sacc. (strawberry leaf blight). — Galloway
recommends the following energetic treatment to destroy this disease :
Spray the strawberries after gathering the crop with 2 per cent acid,
which kills both the old leaves and the spores of the parasite. The new
leaves which spring up are perfectly healthy. Tyron found this treatment
to give as good results as bouillies bordelaise or alkaline sulphides.

Cuscuta (Dodder). — Wagenblicher found that 0'5 per cent acid killed
dodder, but when used on fields of trefoil and lucerne against Cuscuta
Epithymuvi the burning of the plant injured the crop. As a weed-
killer on walks sulphuric acid is defective. The effect is immediate
but the weeds soon sprung up as vigorous as ever. Finally, sulphuric
acid has been prescribed against potato scab. Wilfarth, acting
on the principle that ashes and lime induce this disease, tried to pro-
duce a contrary effect by spreading sulphuric acid on the fields. He
therefore spread sulfarine, a mixture composed of magnesium sulphate
and of 15 per cent sulphuric acid. The results were decisive, as shown
in the following table : —

TABLE XIV. — SJioiuing the Action of Different Doses of Sulfarine (kieserite)
containing 15 per cent of Siilphuric Acid on the Potato Disease.

Dose.

Crop.

Per Cent Diseased.

Blank

76 potatoes of which

80 diseased

2 kg. of sulfarine per m^

77 „ „ 60

7

76.* „ ,, 40

10

73

25

14

73

20

18

65

10

30

•30^

5 „

The disease is, in fact, considerably diminished by this treatment,
but the dose of 14 kilogrammes of sulfarine per square metre must

88 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

not be exceeded, for there would be the risk of too small a crop which
would be as great an evil.

Use of Sulphuric Acid against Insects and Worms. —

Tylenchus Tritica [Bastian] (eel-worm of wheat). — This is a microscopic
worm which causes the blight known in France as Nielle de Froment
[and in Great Britain as "Ear Cockles," "Purples," "False Ergot,"
" Galls of Wheat Eel-worms "]. Davaine in 1889 recommended steep-
ing the affected grain in O'O per cent sulphuric acid for twenty-four
hours, but this method has the drawback of injuring the grain.

Tortrix Vitana (pyralis of the vine). — The VTinter treatment
against anthracnose of the vine by sulphuric acid, not only destroys
the spores of the most formidable cryptogamic parasites, but according
to Debray it also destroys the grubs of this butterfly which pass the
winter in the interstices of the bark. According to the same obsei-ver
the vine cochineal Dactylopius Vitis, which passes the winter fixed
against the wood, may be destroyed by spraying with 10 per cent
acid after the fall of the leaf. The acid employed under like con-
ditions to destroy the Schizoneura lanigera, Haus, did not give the
result expected. To kill icasps it suffices to pour 10-20 per cent acid
into the nest.

8. Chlorine, Clo. — Chlorine is an element widely distributed in
nature in combination with certain metals — sodium, potassium,
magnesium.

Preparation. — By the action of aqueous hydrochloric acid on
manganese dioxide.

MnO, + 4HC1

= MnCl, + 2HoO + CI,

Mangan- Hycli-o-

Mangan- Water. Chlorine

ese chloric

ous

dioxide. acid.

chloride.

Use. — This gas, of some use to kill fungi, is so poisonous to plants
that its use is limited to saprophytic fungi, such as —

Merulius lacrymana, Schm. (dry rot of wood). — As a remedy
chlorine is the subject of a German patent, D.E.P. 76877, according
to which good results are obtained by piercing boards with holes into
which chlorine is introduced ; these holes are then stopped up hermeti-
cally.

Q. Hydrochloric Acid, HCl. — Preparation. — The industrial pre-
paration of this acid is subsidiary to the manufacture of sulphate
of soda, intended for the production of soda ash. It is produced by
decomposing common salt by sulphuric acid.

2NaCl + H,SO, = Na.,SO, + 2HC1
Sodium Sulphuric Sodium Hydro-
chloride, acid. sulphate. chloric

acid.

The salt is introduced into capacious cast-iron cylinders, luted with
clav, and then sulphuric acid is run on to it. The hydrochloric acid
which escapes is dissolved in earthen carboys containing water. Com-
mercial HCl marks 22" by Baume's hydrometer.

Use. — The searching examinations which have been made into the
action of this acid on fungi have shown that its use is not advisable.

HYDEOCHLORIC ACID.

89

because its action on plants is deadly. Bolley, in 1894, tried to use
the antici-yptogamic properties of hydrochloric acid against potato
scab. The germs of this disease are killed, it is true, by steeping
from five to twenty-four hours in a 2 per cent solution of this acid, but
the eyes of the potato suffer so badly that this method cannot be
advantageously used. Wuthrich, in a research published in 1892 on
the action of metallic salts and acids on the spores of different fungi,
proved that the amount of this acid required to prevent the germina-
tion of spores compared with that of sulphuric acid used is proportional
to their chemical equivalents. Thus a solution of 0'0036 of HCl has
the same anticryptogamic effect as a solution of 0'0049 per cent of
HoSO^. A solution of HCl of 0-0036 per cent of sulphuric acid pre-
vents germination of the conidia and zoospores of Phytophthora in-
festans, De By.; the conidia and the zoospores of Peronospora
viticola, De By. ; the spores of Ustilago carbo, Tul. But to prevent the
germination of the uredospores of Puccinia graminis, Pers., acid of
0'036 per cent is required. Hydrochloric acid can replace sulphuric
acid wherever the latter has given good results, if the plant be not
unfortunately as sensitive as the spores of fungi.

Action of Chlorine and Hydrochloric Acid on Plants. — Hydro-
chloric acid and bleaching- powder factories discharge chlorine and
hydrochloric acid vapours into the air. The injurious effect of this
gas makes itself felt sometimes two miles from the factory, a radius
within which it kill plants. This gas is even more poisonous than
sulphurous acid itself ; deciduous trees suffer as well as evergreens.
The pathological condition ol the plant attacked is distinguished by
the brown border which forms on the leaves ; then they are covered
with brown spots. The needles of spruce fir trees become yellow at
the point, dry up, and drop off. The analysis of the dry substance of
the diseased plant twenty-five minutes distant from these factories,
according to Konig, Steffeck, and Heine, gave the following results : —

TABLE XV. — Shoiving the Effect on the Chlorine Content of Forest Timber of
Proximity to a Hydrochloric Acid Works.

Tree.

Condition.

Per cent
Chlorine.

Increase in
Chlorine
Per cent.

Oak .

Beech ....

Larch

Spruce

Hazel

Healthy

Sickly

Healthy

Sickly

Healthy

Sickly

Healthy

Sickly

Healthy

Sickly

0081
0-191
0-211
0-311
0-279
0-767
0-101
0-132
0-178
0-ol6

13.5-8

1

71-14 \
174-91
30-69

189-88

These analyses show that the disease is produced by the absorption of
chlorine and hydrochloric acid.

90 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

lo. Nitric Acid. — Preparation. — The commercial acid is prepared
by introducing into a cast-iron pan 330 kilogrammes (726 lb.) of nitrate
of soda and 420 kilogrammes (964 lb.) of sulphuric acid of 62°
Baume ; the lid is luted with clay and heated. The nitric acid vapours
disengage through an earthen pipe, condense in big carboys, also of
earthenware, placed one after the other, and each containing a little
water. There are thus obtained 440 kilogrammes (968 lb.) of nitric
acid of 36° Baume.

Properties. — Nitric acid is a colourless liquid, sometimes yellow
from the presence of nitrous acid. Its density is 1'52, its boiling-
point is 86° C. It is very corrosive ; in contact with organic matters
it first produces nitrated compounds, then an oxidation which proceeds
so far as destruction. It is quite as dangerous as sulphuric acid, and
should be handled with many precautions.

Action of Nitric Acid on Plants. — The following are the results
of the examination of nitric acids on plants : 0"05 gramme of this
acid in a cubic metre of air produces poisonous effects on plants
analogous to those produced by sulphurous acid ; spots and brown
borders on the leaves ; yellow points on the needles of the conifers.
The normal dose of nitric acid in the air is 0 '00003 per cubic
metx^e ; it therefore requires a dose almost 2000 times stronger to pro-
duce pathological symptoms in the plant such as occur in the neigh-
bourhood of factories which allow the vapour of these acids to escape.

Use. — Nitric acid is not only corrosive but poisonous to insects.
This latter property is manifested, more especially, in organic com-
pounds containing one or more nitro groups. Nitric acid, like sulphuric
acid, has been I'ecommended especially to combat insects in winter.
Its action on fungi is especially injurious. Hitchcock and Carleton
found that the uredospores of Puccinia coronata, Corda (crown rust of
oats) are killed in twenty-four to twenty- six hours in nitric acid of 0*68
per cent, but an acid of 0*068 per cent has no action on these spores.

The spores oiPhytophthora and Peronospora, according to present
knowledge, are destroyed by an acid of about 0*05 per cent. Nitric
acid is not used to combat fungoid parasites except black rot, although
it has been tried against several other cryptogams.

Guignardia Biduiells, Viala et Ravaz (black rot). — Viala, the learned
pi'ofessor of Grignon, proposes to replace sulphuric acid in the winter
treatment of the vine by nitric acid, which destroys the spores of this
fungus. Against insects the first experiment dates as far back as 1872.
Lemoine recommended for the treatment of the phylloxera the coating
of the stems with a mixture consisting of 1 kilogramme of nitric acid
of 60 per cent, 2 grammes of spirits of turpentine, and 4 grammes of
chrome yellow, the whole diluted in 5 litres of water. Examined by
the commission who investigated the chemical products proposed to
combat this insect the above mixture was pronounced defective.

At the present time it is recognized that nitric acid is very injurious
to grubs and may be used wherever these are not on the vegetative part
of the plant. By this method the grubs of the Tortrix Vitana (pyralis
of the vine) and the Conchylis Ambignella, Hubn (cochylis of the
vine), which pass the winter in the fissures of the bark of the stem.

NITRIC ACID.

91

Fig. 6. — Decorticator.

Although Dufour's experiments, which could not destroy the grubs
of the cochylis by steeping them for some seconds in 50 per cent
nitric acid, do not speak in favour of the insecticide action of this acid,
the results obtained in actual practice have been very favourable.
Sourdon and Castel, as well as Debray, have recommended for the
winter treatment of the vine the use of commercial nitric acid diluted
with six times its weight of water. After having barked the vine by
Sabate's iron glove, the eyes, the runners, and the body of the stem
are coated with nitric acid. The method may be applied in all weathers,
and its efficacy is almost always absolute. Debray is of opinion that
nitric acid m^y repla^ce ebouillantage, "scalding," which is a compli-
cated method, and often inapplicable. Like the latter, it frees the vine
from all cryptogamic parasites, and from all insects which seek a refuge
in winter in the corners of the bark. Barbut's observations which in-

FiG. 7. — Sabate's Glove.

duced him to affirm that 10 per cent nitric acid only kills 50 per cent
of pyralis and 40 per cent of cochylis, that the chrysales of pyralis can
stand steeping in that acid for several hours without injury, and that
treatment by nitric acid retards, moreover, the growth of the vine, in
no way diminishes the good results obtained in actual practice, and the
success of the winter treatment of the vine by nitric acid.

CHAPTER V.

PHOSPHORUS — PHOSPHORETTED HYDROGEN — ARSENIURETTED
HYDROGEN— ARSENIOUS SULPHIDE— ARSENIOUS ACID— WHITE
ARSENIC— ARSENIC ACID— BORIC ACID.

II. Phosphorus. — Preparation. — Phosphorus does not occur in
nature in the free state, but as phosphoric acid combined with various
metallic oxides, lime, magnesia, soda, etc. In the industrial manu-
facture bones form the raw material.

Properties. — Phosphorus insoluble in water and alcohol dissolves
in carbon disulphide. It is combustible. It oxidizes in the air at the
ordinary temperature but does not ignite below 60° C. (140° F.). It
melts at 44° C. (111-2° F.). It is preserved underwater. Phosphorus
is a violent poison which, when absorbed even in very small doses,
induces vomiting and epigastric pains. It may act if it continue to be
absorbed on the nervous system, which it depresses, and by paralysing
the heart's action, it rapidly causes death. The intensity of the action
of phosphorus depends on the form under which it is ingested ; dis-
solved in oil, for example, it is much more poisonous than when in
solution in other solvents, because in this form it is precipitated less
easily in the aqueous juices of the stomach.

Use. — Phosphorus is as violent a poison for mammals as for
insects. It is used everywhere where pastes can be used to destroy
noxious animals. To prepare these pastes 50 oz. of boiling water
are run into a porcelain mortar, then 2 oz. of phosphorus which soon
melt therein ; 40 oz. of flour are then added whilst stirring with a
wooden spatula. When the mixture is almost cold 40 oz. of molten
tallow still tepid are run in and 20 oz. of sugar. This paste may be
used indifferently against rodents and cei'tain injurious insects. The
Murides, such as Arvicola (field mice), Mus musculus (domestic
mouse), Mzis agrar'ms (field mouse), Mus ratus (ordinary rat), Mus
decumanus (Surmulot rat), are destroyed by the phosphorus pastes,
the pi-eparation of which is given above. Mohr adds a little glycerine
which preserves them longer in the air. With this poisonous paste
slices of toasted bread are coated which the rodents eat without sus-
picion. According to Crampe it suffices to prepare a paste of boiled
flour which is cooled to 43° C. (109-4° F.) before mixing in the phos-
phorus ; pieces of straw are then dipped into the paste and laid in the
burrow or in the run of the rodents. The latter in trying to remove
them or in walking on them get daubed with pieces of paste on the
hair, and are poisoned by licking themselves.

Amongst the insects killed by phosphorus are : Perlplancta orien-
talis (cockroach). This insect does great damage in hothouses by

(y'i)

AESENIURETTED HYDROGEN. 93

gnawing orchid roots. Paste pills made frona honey and phosphorus
and laid on the pot of the plant attacked rapidly destroy the insect.

Gryllotalpa vulgaris (mole-cricket). — Blias Hugo destroys it by
laying poisoned pastes of maize, starch, water, and phosphorus in the
burrows and stopping up the orifices. The mole-crickets disappear in
twenty-four hours.

Formica (ants). — To poison ants Debray introduces phosphorus
paste made from molasses and phosphorus. The orifices of the nest
are then stopped.

12. Phosphoretted Hydrogen, PH3. — Preparation. — (1) By the
action of phosphorus on caustic alkalies or the hydroxides of the
alkaline earths in presence of water and under the influence of heat.
(2) By decomposition of calcium phosphide by water alone or by
hydrochloric acid.

Properties. — Phosphoretted hydrogen is a colourless gas with a
strong garlic smell, inflaming at 60° C. (140° F.). It is poisonous,
and acts especially by depriving the haemoglobin of the blood of the
oxygen fixed therein.

Use. — Phosphoretted hydrogen is recommended for combating the
phylloxera. Mouillefert showed this gas to be five times more poison-
ous than prussic acid. An atmosphere containing 0*5 per cent of
phosphoretted hydrogen is very injurious to the phylloxeras, but the
latter are not destroyed until after they have been fourteen hours in
an atmosphere containing 1 per cent of this gas. Experiments on
the large scale have given variable results ; those of Mouillefert, a
negative one ; those of Eosler, a perfect one. The former wrought
thus : 20 grammes (310 grains) of phosphide were laid in three holes
of 50-60 centimetres (20-24 inches) in depth, at equal distances round
a stock, and then closed. The moisture and carbonic acid in the soil
decomposed the calcium phosphide. Eosler, on the other hand, re-
commends the digging of holes around the stock, and to lay therein
several layers of quicklime, on which a small piece of phosphorus is
placed. The holes, filled up, are covered with water and then stopped
with clay. Rosier recommends this treatment as efficacious, and
without any injurious effect on the vine treated ; it is done in the spring.
Mouillefert ascribes the bad result of his experiments to the rapid
oxidation which goes on in the soil, and to the feeble diffusion of
phosphoretted hydrogen, which is less rapid than carbon disulphide.

13. Arseniuretted Hydrogen, AsHg. — Preparation. — By decom-
posing certain arsenides, such as those of zinc and tin by dilute sul-
phuric acid. Zinc arsenide is obtained by fusing 100 parts of zinc
with 75 parts of arsenic in an earthenware retort.

As.^Zn3 + 3H.3SO^ = 2ASH3 + 3ZnS0^.

Properties. — Arseniuretted hydrogen is a colourless, inflammable
gas with a strong garlic odour. It is exceedingly poisonous and must
not be breathed even when it is diluted with much air.

Use. — In America it has been tried to destroy the kermes of fruit
trees. Coquillet covered the trees with a tent, under which he caused
ASH3 to be disengaged, but the results were not so satisfactory as

94

INSECTICIDES, FUNGICIDES, AND WEED KILLEKS.

those obtained by prussic acid in similar conditions. This gas is so
poisonous that it can never be used in actual practice.

14. Arsenious Sulphide, As^Sg (yellow orpiment). — Loarer, in
1872, sprayed vines attacked by the phylloxera with a bouillie con-
taining O'l per cent of this product, but without success.

15. Arsenious Acid, AsoOg. — Arsenious acid, or arsenic, is ob-
tained, commercially, by roasting arseniferous minerals, the arsenides,
and sulpharsenides of nickel, cobalt, and iron, in capacious muffles, of
refractory material, round which the flame from the fiie circulates. '

■I.. -.. I [2FeAsS + 30 = 2FeS + AsgOg.

The arsenious anhydride given off is led into cold, superimposed
chambers, where it condenses as a white crystalline powder. It is
removed by raking it out and purified by distilling it in wrought-iron
vessels.

Properties. — White arsenic is a white or colourless, inodorous
solid ; recently fused, it forms a vitreous, transparent, amorphous mass.
White arsenic only dissolves at 13° C. in water, in the ratio of 1'2-
1-3 per cent, whilst the vitreous acid dissolves in the ratio of 4 per
cent. Its taste is at first faint, then bitter and nauseous. Arsenious
acid is a violent poison for all animals, and in a dose of 1 decigramme,
say 1-i grains, kills man. It is a violent escharotic of the mucous
membrane, and of all the tissues in general, which it inflames, and
rapidly destroys. Absorbed by the digestive channels, it gives rise to
gastro-intestinal symptoms, which are often followed by paralysis.
In very small doses it is a pow^erful stimulant, which encourages
growth. This property causes it to be much used in medicine.
Arsenic is as poisonous to plants as to animals. It burns the leaves.
Arsenites soluble in water are the more active the greater their solu-
bility ; those which are insoluble in water consequently have no
injurious action on plants.

Herbaceous plants die when they are watered with a 0"5 per
cent solution. Deciduous trees are also very sensitive to the action
of arsenic. To destroy certain insects, a solution of 200 gi-ammes in
100 litres (2 lb. per 100 gallons) were tried, but even in that propor-
tion the arsenic is still too prejudicial to the leaves.

TABLE XVI. — Showing Sensitiveness of Leaves of Variotis Fruit Trees to Solu-
tions of Arsetiiotis Acid of Various Strengths.

Name of Tree.

Grammes

As.fis per
100 litres.^

Effect on
Leaves.

Name of Tree.

Grammes
As^O^per
100 litres.'^

30

24
15
34

Effect on
Leaves.

Apple
Plum
Plum
Vine

30
15
10

48

Browned

Attacked
Burnt

Negundo Aceroids
Gleditschia Tria-

cauthus .
Poplar
Raspberry .

Burnt

Parts by weight in 100,000 parts by volume.

AKSENIOUS ACID. 95

Gillette found that in a much weaker dose arsenic is still injurious,
and that, in this respect, different plants are not equally sensitive.

These doses being often insufficient to kill the insects, arsenic
solutions were completely abandoned, and replaced by neutral bouillies,
in which the arsenic is generally in the insoluble condition, and thus
in a form which does not injure the plant. Arsenious acid has also
a very decided action on the spores of fungi. This action was long
known and utilized to disinfect cereal grains, when, in 1856, Boussin-
gault recommended the use of arsenite of soda for the disinfection of
grain. This process was, in his opinion, the best for freeing farm crops
from smut, bunt, rust, caries and ergot ; it, moreover, had the advan-
tage of protecting the grain from the ravages of injurious animals
after sowing.

Use. — The French Ordinance of 1846, Article 10, " The sale and use
of arsenic and its compounds are interdicted for the pickling of grain, the
embalming of corpses, and the destruction of insects," has prevented
its use in France, but in other countries the valuable properties of this
product have earned for it numerous applications. The first trials
were made in America in 1867, when Markham used arsenic to com-
bat an insect very deadly to the potato, the Leptinotarsa decemlineata or
Doryphor of Colorado (the Colorado beetle). The use of arsenic
became general in 1871, but especially in the form of neutral bouillies,
with an emerald green or Scheel's green basis, London purple or
arsenite of lime, or in admixture with different anti-cryptogamic salts.
Gillette also recommended, in the form of powder, mixed with much
flour. In this form it has been recognized as less injurious to the
leaves than in solution, and is thus recommended every time that spray-
ing cannot be adopted. To-day white arsenic is hardly used except to
poison the pastes for the following insects : Agriotes lincatus or Elater
segetis, L. (wire worm), injurious to cereals ; Agriotes or Elater
sputator, L. (spitting click beetle), injurious to lettuce ; Agriotes or
Elater obscuriis, L. (dusky click beetle), injurious to carrots. It is
very difiicult to get at the larvae, as they live hidden. Comstock re-
commends to destroy them by pastes poisoned by arsenic. For this
purpose small bundles of lucerne are prepared towards July, of which
the larvae are very fond ; they are dipped in a 1 per cent solution of
arsenious acid, they are then placed in the infected fields, taking care
to cover them with flower-pots so as to keep the lucerne moist which
should always appear as if fresh cut.

Gryllotalpa vulgaris (mole-cricket). — To poison this insect Leh-
mann spreads in the spots frequented by it preparations made thus :
thyme, sweet marjoram, sweet basil, with ground arsenic, earth, or
sand. The mole-crickets, very fond of these seeds, come to eat them
and are poisoned.

Acrydium migratorium (Criquet migrateur) ; Acrydium peregrinum
(Criquet pelerin), — Chemicals are only rarely used to combat these
locusts ; battues and Cypriot's apparatus are preferred. However,
Coquillot recommends the use of poisonous preparations. One lb. of
sugar is dissolved in enough water to form a syrup, there is then
stirred in 1 lb. of arsenic and 6 lb. of bran. This paste is divided into

96 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

pieces the size of a nut and then laid in front of the line of invasion
of the locusts at the distance of a yard and in several parallel rows.

Agrotis segetum, W. V. (the common dart moth) ; Agrotis ex-
clamationis (the heart and dart moth). — Coquillot recommends
bunches of lucerne, steeped in a 1 per cent solution of arsenic, or the
preparation already prescribed to destroy locusts. The preparation is
placed round the stocks of the vines ; the grub, seeking its shelter in
the morning on the vine, grazes the arsenic of the preparation and is
poisoned by contact, for this product kills the insects that touch it as
v^ell as those that absorb it through the digestive channels.

Kermes. — It is asserted that these parasites do not resist a 1 to 3
per cent solution of arsenic.

Phylloxera vastatrix, Planch, (phylloxera of the vine). — The effects
of arsenic on this insect were examined by Cornu, Mouillefert, and
Heckel. Arsenious acid was proposed like other substances at the
moment of the phylloxeric invasion. The insecticide properties of
this product being known, it was hoped to be able to destroy this
formidable insect by watering the soil round the stocks with a dilute
solution of this poison. The phylloxera infected vines, after having
been stripped within a radius of 10 inches round the root, were each
treated with 25 grammes of arsenic dissolved in 10 litres of water.
[Dissolve 2-^ lb. arsenic in 100 gallons water and give each vine 2i
gallons.] The adult phylloxera were found dead, but the young ones
were quite robust. As soon as the diffusive action of the soil had
rendered the arsenic powerless, the phylloxera multiplied once more.
Other trials showed that this dose is quite insufficient to destroy the
phylloxera of the vine. Vines so infected placed in pots containing
4 litres of earth received 1*5 gramme (23 grains) of arsenic in 100
grammes (3^ oz.) of water. This, though a considerable dose, did not
free the vine from its parasites. It corresponded to 375 grammes of
arsenic per cubic metre of soil, and is not withstood by the vine,
which can stand a \ per cent solution, but a \ per cent affects it.
Arsenic has not therefore been judged capable of being taken into
account for the destruction of the phylloxera.

Rodents (mice, rats, field mice, moles). — Arsenic is the poison most
often used to destroy rats. The success of the famous poison " Rough
on Rats " is due to the arsenic it contains.

There are different methods of making these preparations : (1)
Boil wheat in water saturated with arsenic ; boiling must not be too
prolonged, as the grains must remain hard. Place some of the grains,
after wiping them, in each hole. To destroy the field mouse it is
better to operate in winter, when the animal is famished. (2) Mix
100 grammes of arsenic (3^ oz.) with 1 kilogramme of tallow (say
1\ lb.), 4grammesi(say ^ oz.) anise, and 10 grammes (say ^- oz.) lamp-
black. The paste is spread on very thin slices of toasted bread. (3)
Mix 4^ oz. flour with 1 oz. of arsenic and place a little of the powder
in a drain pipe, about 1 ^^ inch in diameter ; place this pipe near the mole
holes. This method keeps the poison beyond the reach of game and
dogs. These pipes can also be used for poisoned grain. (4) Cut a celery
root in two pai'ts, make a cavity in each piece, and fill it with arsenic,

BORIC ACID. 97

then stick the two pieces together by a glue without smell. Thus,
after removing the point of one of these roots a conical hole is made
in it, arsenic placed in the opening s ) made, and closed by the piece
removed, which forms a natural plug. Place the celery so prepared
in the nests. Complete success will be obtained if precaution be taken
to accustom the rodents to this preparation by giving them first non-
poisoned celery.

1 6. Arsenic Acid, As^Oj. — Preparation. — By oxidizing arsenious
acid by nitric acid.

Properties. — Arsenic anhydride is a white solid. It dissolves
slowly in water. It is a more violent and more rapid poison than
arsenious acid.

Use. — Arsenic acid has been proposed for the disinfection of seed-
corn. A powder is prepared with 9 parts of lime and 1 of arsenic
acid, with which the corn kept moist is sprinkled in the proportion of
3J lb. per 2f bushels of grain. After twenty-four hours the seeds
were dried and sown.

17. Boric Acid, B.^Og. — Occurrence. — Occurs in nature some-
times free, sometimes combined v^dth bases.

Preparation. — By decomposing borax (sodium diborate) by hydro-
chloric acid. Borax is dissolved in four times its weight of water and
hydrochloric acid added to a decidedly acid reaction. Boric acid
crystallises out as shining scales on cooling, is drained and washed
with cold water.

Properties. — Boric acid occurs as shining scales, but little soluble
in water ; 4 per cent at 20° C. It is a weak antiseptic. To preserve
meat for three weeks it must be steeped in a 4 per cent solution.

Use. — Kuhn has examined its antiseptic power on bacteria. A

1 per cent solution does not stop their growth. A 2 per cent solution
stops the growth of bacteria. Even a 4 per cent solution does not kill
them. The alcoholic fermentation of saccharine solutions containing

2 per cent boric acid is not completely arrested (Schwartz). Constantin
and Dufour tried without success a 2 per cent boric acid solution to
kill the mole disease of the mushroom {Mycogone perniciosa).

CHAPTER. VI.

AMMONIA— AMMONIUM SULPHIDE— AMMONIUM SULPHOCYANIDE— AM-
MONIUM SULPHATE — AMMONIUM CARBONATE — SODIUM HYPO-
SULPHITE—SODIUM SULPHATE — SODIUM CHLOEipE (COMMON
SALT)— SODIUM NITRATE (CHILI SALTPETRE) — ARSENITE OF
SODA— BORAX— SODIUM CARBONATE.

1 8. Ammonia, NH3. — Preparation. — By distilling ammonlcal gas
liquor or fermented urine with lime.

Properties. — Ammonia is a colourless gas with a pungent smell,
which irritates the mucous membranes, and an acrid taste. Aqueous
solutions are met with in commerce, as liquor ammoniac, containing
about 30 per cent of ammonia gas. Such solutions rapidlj'- alter in
the air by the evaporation of the dissolved gas. Owing to its causticity
ammonia is employed in medicine as a rubefacient, or to induce
vesication. Ammonia is one of the nutritive substances of the plant,
and its presence in the air greatly stimulates the growth of the latter.
Normally the air does not contain more than 0'056 milligramme of am-
monia per cubic metre, but this dose varies much. The amount varies
according to the altitude : at 395 metres, 0*9 to 2"76 milligrammes ;
at 1446 metres, 3"18 milligrammes ; and at 1884 metres, 5'5 milli-
grammes. The dose injurious to plants is about 1000 times gi'eater
than the normal dose. Some plants are more sensitive than others
(Meyer). Whilst 243 milligrammes of ammonia per cubic metre
of air had no bad effect on oaks, even if they remained an hour in that
atmosphere, 70-86 milligrammes caused a pathological condition on
plum-trees and cherry-trees. A dose of 32-36 milligrammes of ammonia
per cubic metre has no caustic action on the most sensitive of vege-
tables. The symptoms of burning by ammonia are the following : The
leaves of the oak blacken ; those of cherry-trees and plum-trees become
brown ; haricots blacken ; and cereals lose their colour and become
quite pale. Young buds are much more sensitive than old leaves. A
0"003-0"005 per cent solution has no action on the protoplasma of
maize, haricots, tomatoes, and strawberry plants ; more concentrated
solutions increase the movements of the protoplasma.

The seeds of Phaseolus muUiflora germinate in nine days in an
atmosphere containing 0-003-0-004 per cent of ammonia ; likewise the
seeds of Vicia faba, when the ambient air contains 0'0031 per cent of
this gas. In an atmosphere containing 0"005 per cent of ammonia
leguminous seeds cannot germinate, and a 0*0083 per cent solution
exercises an unfavourable action on young maize, owing to its
diminished growth.

Use. — The causticity of ammonia being known, it is evident that

cjy)

AMMONIUM SULPHIDE. 99

care must be taken not to bring it in contact with plants. Annwonia
enters into the composition of certain anticryptogamic bouilhes, and
chiefly eau celeste used to kill mildew. The good effects of this pre-
paration are indisputable ; but they can only be obtained by working
with an absolutely neutral solution, a point which does not receive in
the majority of cases the serious supervision which it requires. It
follows that mishaps occur, which should not be produced with a sub-
stance possessing all the properties that can be desired. Pure ammonia
has few applications in agriculture. However, gas liquor, which is
cheap, is in general use. These ammoniacal liquors kill mosses in
meadows and impart fresh vigour to grain crops. But in the condi-
tion in which they are bought these liquors are too concentrated, and
might kill graminaceous crops. They must be reduced by an equal
quantity of ordinary water, and only 4000 litres of this mixture spread
per hectare (352 gallons per acre) (Noffray). The following diseases
are combated by ammoniacal treatment : —

Heterodera Schachtil, Schmidt (nematode of the beet). — Willot has
published very satisfactory results which he has obtained by the use
of ammoniacal liquors. The infested beet fields, producing, on an
average, 4 tons of beets per hectare, say 1-6 ton per acre, yielded
37 tons per hectare, say 14"4 tons per acre. In Willot's brevet the
nematodes succumb to the alkaline action of gas liquors, provided
they contain 5 per cent of ammonia. The results obtained by others
have not been so favourable. Hollrung, Strohmer, and Stift have,
in fact, energetically combated the ef&cacy of this treatment, their
experiments having given no satisfactory result. Hollrung even
remarks that beet seed was not capable of springing up in a soil
treated with ammoniacal liquor. To avoid this drawback Willot
follows up his treatment by spraying with ordinary water. Be that,
as it may, this treatment cannot be so efficacious as that due to Aime
Girard, which consists in using a strong dose of carbon disulphide, and
which ought always to be preferred.

Jassus sexnotatus (grain grasshopper). — Steglich recommends
ammoniacal liquor of gasworks, in which 2 per cent of soft soap is
dissolved, the whole diluted with an equal bulk of water, to get rid of
this pest. Sorauer eulogizes the good effects of this treatment, and
recommends spraying with a solution made in the ratio of 30 lb. of
soft soap and 3 gallons of commercial ammonia in 100 gallons of
water. Muhlberg's experiments with gaseous ammonia and am-
moniacal liquors to destroy the Schizoneura lanigera (woolly aphis) ;
Coquillet's to destroy kermes ; Voiret and Gervais's, then Mouillefert's,
to combat phylloxera of the vine, have given negative results.

19. Ammonium Sulphide, (NHJoS. — Preparation. — Am-
monia forms, when combined with a semi-molecule of sulphuretted
hydrogen, hydrosulphide of ammonia or ammonium sulphide.

Properties. — Ammonium sulphide is crystalline, colourless, and
very soluble in water.

Use. — Demato2)liora nccatrix, Hartig (root rot). — Dufour tried to
replace carbon disulphide by this substance, but the results obtained
were not perceptible.

100 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

PJiijlloxera vastatrix, Planch, (phylloxera of the vine). — Mouille-
fei't found that the phylloxera dies in twenty-four hours in an
atmosphere containing 1 per cent of ammonium sulphide. Used
in small dose on a vine in pot where the whole soil could be impreg-
nated with this substance, the result was satisfactory, but on the
large scale diffusion is not so perfect, and the result was always in-
complete in spite of the toxicity of the two gases which form this
salt, ammonia and hydrogen sulphide. Mouillefert experimented
thus : The stocks, stripped to 30-35 centimetres (12-14 inches), were
watered with 400 cubic centimetres of the liquid sulphide, then with
10 litres of water ; after the liquid was absorbed the earth was put
back round the stock. On roots 50-60 centimetres (20-24 inches) deep
the effect was, so to speak, nil, and it was even observed that the phyl-
loxeras had not been entirely destroyed on the upper roots. According
to Couvy and Kohart, this bad result was due to the ammonium sulphide
rapidly decomposing in the soil to form inert combinations such as
ammonium sulphate.

Conchylis Ambignella, Hubn. (cochylis of the vine). — Dufour re-
commends against the grub of this butterfly a solution of 3 per cent of
ammonium sulphide and 3 per cent of soft soap, which he regards as
being more efficacious than carbon disulphide.

20. Ammonium Sulphocyanide, NH^CNS. —Preparation. —
By heating potassium sulphocyanide with ammonium chloride.

Properties. — A crystalline salt soluble in water. Its action on
fungi seems less toxic than that of potassium sulphocyanide. A O'l
per cent solution of this salt has no bad effect on the development of
the uredospores of Puccinia coronata, Cord., even after an immersion
of twenty-seven hours. Schumann found that by watering meadows
with a solution of this salt, at the rate of 200 kilogrammes per hectare
(176 lb. per acre), the aerial part of the herbage is killed and growth
much weakened.

21. Ammonium Sulphate (NHJ^SO^. — Sulphate of ammonia
is manufactured commercially by distilling the ammoniacal liquor of
gasworks and putrid urine. The volatile portions are collected in
dilute sulphuric acid, the liquors obtained are concentrated in lead
tanks, where the sulphate of ammonia crystallizes in prisms.

Properties. — Ammonium sulphate forms anhydrous permanent
prisms. It dissolves in 2 parts of cold and 1 of boiling water.

Uses. — As an ammoniacal manure.

Heliopliobus pojjularis. — Amongst the insecticides used to destroy
the grub of this Lepidoptera, which causes such damage to meadows,
Marchand found that only a 10 per cent solution of ammonium sul-
phate in purin gave appreciable results.

Phylloxera vastatrix, Planch, (phylloxera of the vine). — According
to Hosier's experiments on the phylloxera, with the most diverse sub-
stances, ammonia had on these plant-lice as energetic an effect as
carbon disulphide and sulphuretted hydrogen, but that it had not such
a poisonous effect on the plant as the two latter gases. To generate
the ammonia gas in the zone invaded by the louse, Rosier recommends
to pierce holes with the pal round the vine, and to fill them either

ft

AMMONIUM CARBONATE. 101

with alternate layers of newly slaked linae and ammonium sulphate,
and spray afterwards with water, or with lime alone, and then spray
with a solution of sulphate of ammonia. The holes are then plugged
with clay or wooden plugs. The ammonia gas generated by the
mixture of these substances reaches the phylloxera, and infallibly
kills it.

Mouillefert determined that if the phylloxera be sensitive to
ammonia it is difficult on the large scale to destroy it with ammonia-
cal liquor. A phylloxera-infested root dipped for three minutes in
ordinary ammonia, or exposed for an hour to the vapours of 5 cubic
centimetres of this substance in a 2-litre bottle was freed from all its
parasites, but these experiments repeated on a phylloxera-infested
vine in pot gave no good results. For that purpose 10 cubic centi-
metres of ammonia were poured into two holes which were immediately
plugged. The beards of the root in existence before the experiment
were destroyed and the swellings on the large roots still bore numerous
parasites. Ammoniacal liquor, according to this experiment, is not,
therefore, capable of destroying the phylloxera without imparting
grave injuries to the plant. In fact, 20 cubic centimetres of this
liquor employed in the same conditions on a healthy vine burnt the
leaves, and 40 centimetres killed them. Ammonia used as vapour
does not appear to have the injurious action of ammoniacal liquor on
plants. Ammonium sulphate used according to Hosier's indications,
may thus have as great an action on the phylloxeras as it has on the
vine, by imparting new vigour to it in virtue of its nutritive properties.

22. Ammonium Carbonate (NH^j^COa. — Preparation. — By
heating in a cast-iron retort an intimate mixture of equal weights of
ammonium sulphate and chalk. The volatile salt is condensed in a
receiver.

Properties. — Ammonium carbonate is a transparent crystalline
salt with a caustic taste and exhaling ammoniacal odour. In contact
with air it loses a part of its ammonia and is converted into a more
stable bi-carbonate. Solutions of ammonium carbonate are com-
pletely dissociated into ammonia and carbonic acid when heated.

Use. — Hitchcock and Carleton have observed that a 1 per cent solu-
tion of ammonium carbonate stopped the gi'owth of the uredospores of
Puccinia coronata, Corda, after seventeen hours' action.

Phylloxera vastatrix, Planch, (phylloxera of the vine), — The effects
of ammoniacal manure, such as ammonium carbonate, which stable
manure contains in notable quantities, have always been successful
on phylloxera-infested vines. Eosler ascribes this to the ready dis-
sociation of this salt into ammonia — especially poisonous to the
phylloxera — and carbonic acid. So as to render it still more active, he
advises the manure containing the ammonium carbonate to be spread
in the spring, because the young generations of phylloxera are much
more sensitive than the adults. Mouillefert is of another opinion.
According to his experiments a solution at the rate of 2 lb. of this
salt in 25 gallons of water with which he watered a phylloxera-infested
vine was incapable of killing the phylloxeras. He concluded that
ammoniacal salts only acted as fortifiers of the plant.

102 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

23. Hyposulphite of Soda, Na^,S2035HoO. — Preparation.— Sul-
phites boiled in presence of sulphur are converted into hyposulphites.
To accomplish this, a solution of sulphite of soda is boiled with excess
of sulphur until saturated ; it is filtered and cooled. Large crystals of
sodium hyposulphite form. Commercially this salt is prepared by the
action of sulphurous acid on calcium sulphide (alkali waste). The
hyposulphite of lime formed is converted by sodium sulphate into
sulphate of lime and hyposulphite of soda.

Properties. — Hyposulphite of soda is a colourless salt, permanent
in air, with a bitter taste and very soluble in water. It is less stable
in solution than in crystals ; even in the absence of air it is decomposed
into sulphite of soda and free sulphur which is deposited. In contact
with acids the hyposulphite is decomposed into fine sulphur and
sulphurous acid : —

Na.^S.Oa + 2HC1 = 2NaCl + H.O + SO., + S.

Heated out of contact with air it splits up into sodium pentasulphide
and sodium sulphate. The use of sodium sulphite has been recom-
mended in medicine, especially against itch. Eubbing with a solu-
tion of hyposulphite of soda is followed by washing with dilute hydro-
chloric acid. The sulphurous acid disengaged and the sulphur pre-
cipitated in the pores of the skin make the sulphite a very efficacious
agent in the destruction of this acarus.

Action on Plants. — The hyposulphite acts like the sulphite of
soda and sulphurous acid. Absorbed by the leaves of plants it is there
converted into sulphuric acid and burns the leaves. The experiments
therefore to replace sulphur by this salt which, so to speak, contains
dissolved sulphur have been abortive because it burns the leaves, and
the more so the greater the heat. Kaserer observes that it suffices to
use a solution of hyposulphite rendered alkaline by milk of lime to
obviate this drawback.

Action on Fungi. — Sulphur in hyposulphite of soda preserves its
anticryptogamic properties and imparts them to it. Like sulphur
hyposulphite of soda has been recognized as capable of killing all
fungi, the mycelium of which crawls on the surface of the plant.

Puccinla Coronata, Cord, (coronated rust of oats). — Hitchcock
and Carleton examined the action of solutions of hyposulphite on
the uredospores of this rust and found that a 1 per cent solution has
no injurious action thereon, but it exerts a retarding action on the
germination and a diminution thereof on the seed steeped therein for
twenty-six hours.

Uncinula Americana, How. (oidium of the vine). — Pauly examined
the action on oidium of a double hyposulphite of soda and silver.
After a microscopical examination he observed the great alteration
undergone by the mycelium in contact with a solution containing 0*1
to 0'2 per cent of this salt, and concluded that the use of this salt as
a curative agent would give good results. However this salt, sold
under the name of " Puknos," has been abandoned in the treatment of
the vine because it burned the leaves especially during great heat, and
tbat mucli moie so than the sublimed sulphur which it was to replace.

SODIUM SULPHATE. 103

By adding 300 grammes of hyposulphite of soda to a 1"5 per cent
bouilUe bordelaise. Kaserer obtained by three sprayings in a year
complete success in treating oidium without the treatment being
followed by the burning of the leaves. Solutions of hyposulphite
to which milk of lime was added have been found more energetic than
sulphur.

SphcBTotheca pannosa (mildew of the rose). — Vesque proposes
hyposulphite of soda to destroy mildew of the rose.

Guignardia Bidwelli, Viala et Eavay (black rot of vine). — Pauly
remarks that the double salt, hyposulphite of soda and silver, is
capable of arresting the progress of the black rot in full evolution ;
used in a 1 per cent solution its effect on the spores and the mycelium
is most conclusive. This product has therefore been used to destroy
this disease by making three sprayings per annum on the attacked
vines. This treatment, which burned the leaves, has not been the
success anticipated.

Crouzel's anticryptogamic which contains both calcium poly-
sulphide and a little naphthaline, and 0"2 per cent of hyposulphite of
soda is recommended to combat the cryptogamic diseases of the vine,
and particularly the black rot and the oidium. Spraying should
alternate with five or six days' interval with those made from copper
preparations.

Deynatojyhora necatrix, Hartig (white root rot). — Dufour used this
salt without appreciable result.

24. Sodium Sulphate, Na^SO^. — Occurrence. — In Spain vast
mines of sodium sulphate have been exploited for some years.

Preparation. — -By decomposing sodium chloride by sulphuric
acid : —

2NaCl + H,SO, = Na.SO^ + 2HC1.

Properties. — Crystallized sodium sulphate or Glauber's salt con-
tains 10 molecules of water of crystallization. Heated, these crystals
melt in their water of crystallization and lose it by igneous fusion.
Anhydrous sodium sulphate, a white amorphous powder, is formed.
Sodium sulphate reaches its maximum solubility in water at 33° G.
It is a neutral body which has no action on plants except when highly
concentrated. Seeds, however, do not stand without injury prolonged
immersion in a bath of 2 per cent of sulphate of soda.

Use. — Mathieu de Dombasle discovered the injurious action of
this salt on the spores of smut and bunt, and proposed it
to replace common salt then in use to disinfect grain by sodium
sulphate. The process in use up to then had many drawbacks. It
consisted in macerating the grain in a mixture of lime and common
salt for twenty-four hours, and only gave incomplete results. The
use of the " Absolute Preservative of Mathieu de Dombasle " was a
real progress from all points of view ; it shortened the long immersion
and gave a better result without injuring the grain treated. Process. —
Dissolve 8 kilogrammes (17-6 lb.) of sodium sulphate in 100 litres (22
gallons) of water. Spread on the water-tight fioor (of a ground floor)
1 hectolitre (2| bushels) of the grain to be disinfected and wate: the^

104 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

heap with this solution, stirring with the shovel until all the grains are
well moistened. Then spread 2 kilogrammes (4*4 lb.) of lime recently
slaked over the moistened grain, and stir the heap until all the grains
are covered with a layer of lime. Hequet d'Herval declares that the
success of this treatment is complete, and Loverdo regards this process
as that which gives the best result, after Kuhn's blue vitriol disinfection
process. Sulphate of soda is, moreover, less injurious to the grain than
blue vitriol. Comes has slightly modified this treatment and advises
that the spraying of the heap of grain be replaced by immersion in a
solution of sulphate of soda. It suffices to immerse the seeds in a
concentrated solution of sulphate of soda so that they are completely
covered, then add milk of lime and stir for two hours, then spread the
grain out to dry. G. Arieti estimates that sulphate of soda has a
more injurious action on the spores of Tilletia (bunt) than sulphate of
potash. He advises not to exceed a 2 per cent solution for the sake
of the vitality of the grain, this quantity being quite sufficient to fulfil
the object of sulphating (pickling).

25. Sodium Chloride (Common Salt), NaCl. — Occurrence. —
Common salt is found crystallized in thick beds in certain countries.
It also occurs in solution in sea-water and certain springs. The mines
of rock salt of Cordona (Spain), those of Wieliczka and of Bochnia in
Poland, contain large quantities, and the purity of the product is so
great that it suffices to pulverize the salt of these mines to impart to it
a commercial form. A large amount of the salt used in commerce is
obtained by the evaporation of sea-water. This operation is conducted
on the horizontal surface of a clay soil. To facilitate the feeding of
these basins they are placed below sea-level and form "Salines".
Those of the Mediterranean extend from Hyeres as far as Pori Vendres.
The evaporation of the sea-water is generally conducted in basins in
which are deposited, until sufficiently concentrated, ihe different salts
less soluble than common salt likewise found in solution in that water.
Finally, it is run in layers of 5 centimetres into the smallest basins
called " tables salants " (salt table), in which the salt crystallizes. The
mother liquors are run off and the salt is lifted out by special flat
shovels.

Properties. — Salt is met with as anhydrous crystals. The degree
of solubility of the salt in water varies little, whatever be the tempera-
ture ; 100 grammes of water at 18" C. dissolve 36 grammes of salt, and
at 100° C. 40 grammes. Its use is necessary in the nutrition of the
animal ; administered in too high a dose, it cannot be eliminated by the
skin, the kidneys, and the intestines, and remaining accumulated in
the blood it may coagulate the albumen.

Role of Common Salt. — According to Sachs, Peligot, and Fraisse,
sodium chloride or its elements, with few exceptions, are present in
almost all plants. A feeble dose of common salt may thus act as
a manure for plants, but a strong dose may be so injurious as to kill
them. Braconnot, Schublei-, and Meyer have shown that if the quantity
of salt used exceeds a certain dose, it stops geimination of the seed
and the growth of plants. Dietei-ich proved that big doses of salt
completely paralyse the first phases of plant life, and prevent the

SODIUM CHLORIDE (COMMON SALT). 105

development of the plant. But all plants and all seeds do not stand
the action of salt to the same extent. As a result of some laboratory
experiments, it is recognized that barley stands stronger doses of salt
than tares, and oleaginous seeds resist salt better than other seeds.

Role of Common Salt as Manure. — To a greater extent than
potassium the sodium necessary to the plant exists in all soils in
sufficient quantity. Practice has, however, shown that the application
of common salt to a soil rich in sodium is always followed by good
results, provided always that a certain dose is not exceeded. In these
conditions it is evident that it cannot act as (plant) food, and its role
must be regarded from another point of view, and possibly the follow-
ing. According to Braconnot, one of the first eifects of salt added
to a soil is to keep it moist. This property, which the salt owes
to its affinity for water, is in a high degree favourable to the transport
of the elements assimilated in the plant. Liebig, Voelcker, Malaguti,
and Peligot agree in attributing to common salt the role of a solvent
of phosphate of lime. Liebig in fact found that a solution of 1 kilo-
gramme (2-2 lb.) of common salt in 500 litres (110 gallons) of
water dissolves 15 grammes, say ^ oz., of phosphate of lime.
According to Boussingault, common salt decomposes carbonate of
lime into calcium chloride and carbonate of soda (this action has
been disputed by Kuhlmann, Isidore Pierre, and Peligot) ; the latter
product would be absorbed by the plant, or would act in the soil on
the organic matter to hasten its oxidation and contribute to the forma-
tion of nitrate of soda. The good effects of salt may be confirmed by
spreading a small quantity on the land. In big doses it is, on the
contrary, antiseptic and prevents the putrefaction of organic matter in
the soil, and consequently the formation of nitrates. The nitrification
of organic matter goes on slowly in cold weather ; salt, therefore, has
more action in southern countries than in northern countries
(Kuhlmann). For the action of salt on arable land to be complete
heat and moisture must be intermittent. In two dry years like 1846
and 1865 salt may be injurious because it then acts as a caustic, and
corrodes the plant (Fraisse). Plants on the sea-coast are watered
naturally by the salt water of the sea. There, where the desiccating
action of the wind cannot wither up the plants behind the walls, the
hedges, or the ramparts formed by forests, vegetation becomes
luxuriant. It is otherwise quite on the seashore, the excess of salt,
especially magnesium chloride, being as injurious to plants as the
drying wind. Barren zones are thus to be found along i the shore,
according to whether the wind blows more or less frequently from the
sea and according to the dryness of the year. The remarkable fertility
of the " polders " of Holland is attributed to the temporary submersion
of certain land a hundred years ago. In Camargue the soil is highly
fertile, but the young blades of cereals must be protected by a layer
of reeds, so as to prevent too great drying. The experiments of Lecocq
have shown that it requires 150-200 kilogrammes (330-440 lb.) of
common salt per hectare, say 132-176 lb. per acre, as a manure for
lucerne, 250-300 kilogrammes (550-660 lb., say 220-264 lb. per acre)
for flax and wheat, and 264 lb. per acre for barley. Kuhlmann,

106 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Dubreuil, Fauchet, and Girardin have confirmed these figures and give
264-440 lb. per acre as a suitable dose.

Use against Injurious Plants. — Salt in excess is injurious, and
certain plants stand it with difficulty. Wendler found common salt
an excellent means of destroying charlock.

Destruction of Moss in Meadows and Weeds in Walks. — A
strong dose of salt has a corrosive action on delicate plants ; thus
mosses and horse-tails which invade meadows succumb long before the
gramineae. Used on meadows and fields in a dose to kill moss, it only
retards the growth of the gramineae ; applied on corn fields, it keeps
the stem shorter, imparts a certain rigidity and prevents laying.
Watering paths with a 10 per cent solution is the method used to
destroy weeds ; unfortunately it only destroys them momentarily and
imperfectly because they spring up again as soon as rain comes to
wipe out the treatment.

.Use of Common 5alt against the Diseases of Plants. — Bac-
terian diseases of the potato, scab, crevices, etc. — Becquerel experi-
mented with common salt on the diseases of the potato. This product,
in big doses, being an antiseptic, it might, therefore, prevent the ex-
tension of these diseases. The potatoes were planted in winter, and
to prevent the frost getting at them the tubers were planted at a depth
of 15 inches, with 10 grammes of salt, the others without any saline
manure. In the salted ground the potatoes could be harvested two
months before the normal time, and whilst on the ordinary soil there
were 10 per cent of diseased potatoes, on the soils supplied with salt
all the tubers were sound. Techemacher and Neumann came to the
same conclusion, and according to Peters there is even an increased
yield, but on the other hand a diminution in the total amount of starch.
The same result occurs, therefore, as with the beet ; the improvement
brought to bear on this crop by common salt, and the increased yield
are rather illusory, since as Grouven, Pingen, and Hert have shown,
the weight of the beet increases whilst that of the sugar diminishes.

Peronospora Viticola, De By. (mildew of the vine). — Eecommended
in Germany towards 1882 the spraying of vines with a 2 per cent
solution of common salt : having given no result, was soon abandoned.

Bust of Cereals. — Solutions of common salt were tried to combat
this disease on the adult plants. Feburier and Phillipar obtained
good results by spreading either salt or a mixture of salt and lime on
the crop, but this improvement has been disputed by Loverdo.

Use in the Destruction of insects. — Salt is not an insecticide,
but its presence in the soil sometimes renders a sojourn there im-
possible or disagreeable to certain insects.

Ayriotes Uneatus, L. (wire-worm). — The larvae of this insect have
been combated by spreading a strong dose of salt on the fields. Com-
stock and Slingeiland found that by mixing 10 tons of salt per hectare
(4 tons per acre) with 10 centimetres (4 inches) of the arable surface,
soil these larva) died ; with only 7i tons per hectare (3 tons per acre), the
effects were imperceptible. Unfortunately to obtain good results such
large doses of common salt must be used that growth cannot take
place norina!l>- ; hence it has been advised to apply salt during the bare

SODIUM NITRATE (NITRATE OF SODA). 107

fallow, as the latter is incapal)le by itself of diminishing the number
of polyphagous larvge.

Pieris (white cabbage butterfly). — The grubs of the Pierides,
which ravage cabbages, may be destroyed by watering the latter with
a solution containing 250 grammes of salt and 250 grammes of
tobacco juice in 14 litres of water, say 1 lb. salt and 1 lb tobacco
juice in 5-6 gallons of water.

Salt has been used to kill plant lice.

Phylloxera vasfatrix, Planch, (phylloxera). — Salt, recommended
by so many practical men to kill the phylloxera, has been found by
Mouillefert as absolutely inactive. A dose inconvenient to this plant
louse would be quite as injurious to the vine, because the latter dies if
the soil contains a certain amount of salt. According to the experi-
ments of Viola on the vine in pot, a dose of 200 grammes, say 7 oz.,
kills this plant in eight days.

Schizoneiira lanigera, Hausm. (woolly aphis). — Kratft recommends
the following emulsion, which yields a satisfactory result : Petrol
800 cubic centimetres, salt water, 25 per cent, 200 cubic centi-
metres.

Asjjidiotus pernici.osus, Comst. (the San Jose louse). — In California
there is employed against this cochineal a mixture of lime, sulphur,
and salt, but this preparation has been abandoned in the Eastern
states owing to certain failures, and better results got by the use of
whale-oil soap-emulsions.

Use of Salt to Preserve Green Fodder during Winter. — 1. Plants
mowed green are left on the ground for one or two days. They
partially dry and lose about half their weight. They are then conveyed
into rectangular pits, l'7-2 metres deep, dug out of compact ground,
clay, if possible. A layer of the mown plants is laid 15-20 centimetres
(6-8 inches) deep, w^hich is compressed under foot then sprinkled with
a thin layer of salt. Another layer of plants is laid down, then a layer
of salt, and so on, until the pit is completely full, and even to 1 metre
(40 inches) or 1'3 metre (53 inches) above the level of the ground.
Care must be taken to sjDread the salt in larger quantities on the edges
and corners of the pit. The whole is afterwards covered with a layer
of 60-70 centimetres (24-28 inches) of soil. The fissures produced dur-
ing natural shrinking should be stopped. The cover is in the form of a
sloping roof. This cover is absolutely necessary. For a ton of beet
leaves it requires 2^-3 kilometres of salt, say 5*5 to 6'6 lb. The
ensilage should not last more than two days. Fermentation soon
commences, and reduces the mass to half its bulk. The fodder extracted
from these silos may be given as food to animals without injuring their
health.

2. Moist hay is dried and mixed with salt. Sinclair, Hell (?Hill),
Kausler, Flandrin, and Schattenmann, recommended to sprinkle the
different layers of hay with salt in proportion as they enter the silo.
The salt absorbs the moisture and preserves the hay from all fermen-
tation and mould. The dose should be 2 kilogrammes (4-4 lb.) per
metric ton of hay.

26. Nitrate of Soda, NaNO„. — Occurrence. — Nitrate of soda or

108 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Chili saltpetre forms thick beds, which extend on the surface of the-
soil under a thin bed of clay.

Properties. — The crystals of nitrate of soda are anhydrous, per-
manent in dry air, but deliquescent in moist air. They are much more
soluble in hot water than in cold water ; 100 grammes of water dissolve
80 grammes of nitrate at 10" C. and 217 grammes at 119° C.

Action on Plants. — Nitrate of soda is a plant food, but like most
salts in strong solution, it is injurious to certain plants. Steglich
submitted the most diverse plants to a 30 per cent solution and to one
of 15 per cent with the following results : —

TABLE XVIL — Shoiving the Effect of a 30 ^jer cent Solution A and of a 15 j^er
cent Sohition B of Nitrate of Soda on Different Plants.

Pla.7its.

A

B

Plants.

A

B

Grain .
Beets
Potatoes
Trefoil .
Lupine .
Flax .

Fleeting 5-7 days

Nil

Deadly

Slight

Deadly

Nil

Deadly

Nil
Deadly

Charlock .
Sorrel
Knot grass
Horsetail .
Peas
Mustard .

Very sensitive

Nil

Deadly

Very sensitive
Nil

Deadly

The property of nitrate of soda of killing certain plants without killing
others has been utilized in farming to free fields invaded by certain
adventitious plants. Duserre recommends the use of a 20 per cent
solution to destroy mustard in cornfields. It is preferable not to use
nitrate of soda alone, but mixed with a little blue vitriol. The young
mustard dies after watering with a solution containing 10 per cent of
nitrate of soda and 2 per cent of blue vitriol. Older mustard requires
a solution containing 3 per cent of blue vitriol and up to 20 per cent
of nitrate of soda ; 10 hectolitres (22 gallons) of this solution are
required per hectare (2^ acres). The use of nitrate of soda has, in
this case, the advantage of serving as a manure to the grain crops,
and by stimulating their growth renders them more apt to struggle
against parasites. However, Nijpels believes that nitrate of soda, as
the sole manure, encourages the development of the rust of cereals.

Action on Fungi. — Nitrate of soda should, logically, act like
nitrate of potash on the spores of fungi. The latter salt has been
studied in a vei-y complete manner by Wuthrich.

Action on Insects. — Smith regards a 4 per cent solution of niti-ate
of soda as a good insecticide. Concentrated solutions of nitrate of
soda spread on the land are injurious, according to Miss Ormerod, to
the larvye of the Tipula ; according to Taschenberg, to the larva3 of the
Elaterides ; and according to Weiss, to Nematodes, and particularly to
the TylcnchuH decastatrix, Kuhn (eelworms of wheat), which cause the
disease known as the Niel dn Froment.

27. Arsenite of Soda, Na^As.^Or,. — Preparation. — By boiling 1
part of arscnious acid with 2 parts of soda ash.

Properties. — Arsenite of soda is much more soluble in water

BORAX. 109

than white aiseaic and consequently much more poisonous to plants.
In the composition of arsenical bouillies its formation must be guarded
against, or its effects neutralized by the addition of lime.

Use. — -The soluble arsenites, such as the salts of potassium, '
ammonium, as well as the soda salt, have been serviceable owing to
their great solubility and their immediate action on insects and in-
jurious animals. But this use is, perforce, limited, and then can only
be used to poison preparations to be eaten by insects and rodents.

Disinfection of Seed-Corn. — Boussingault proposed in 1856 to re-
place arsenic by arsenite of soda. He recommended to water gradu-
ally with constant stirring 2f bushels of grain with a solution of 200
grammes of arsenic and 600 grammes of soda crystals in a few litres of
water. In an hour the grain was spread out to dry. This method
was abandoned long ago.

Preparations to Kill Locusts. — In the British Colonies they
prevent the migration of locusts by placing in their way bunches of
fodder, herbs, or maize stems, steeped in a solution containing per
hectolitre 60 grammes of arsenious acid, 60 grammes of caustic soda,
and 10 kilogrammes of white sugar or molasses [or 60 oz. (wt.) of
arsenious acid, 60 oz. of caustic soda by weight, and 1000 oz. of
sugar (wt.) in 100,000 fluid ounces of water]. Drying is prevented
by covering the bait with a board or a stone. This bait may be used
for other insects.

28. Borax, Na^B^O-.. — Occurrence. — Borax occurs naturally in
the lakes of Asia, from which it is extracted by evaporation and crystal-
lization.

Preparation. — By gradually adding 100 lb. of Tuscan boric acid
to 125 lb of soda crystals dissolved in 20 gallons of water and then
heating by steam. The mixture is concentrated to 30° B., and cooled
slowly ; crystals of borax form at the bottom of the receiver. The
double borate of soda and lime, or boronatrocalcite, is widely distributed
in America ; it is now used to manufacture a large amount of borax
obtained by boiling this product with carbonate of soda.

Properties. — Borax is freely soluble in water. A hundred lb. of
borax dissolve in 120 gallons of cold water and the same amount in
20 gallons of boiling water. Its solutions react alkaline. Borax is
used in medicine as an antiseptic, especially in throat and mucous
affections. It is used to preserve meat and putrescible liquors.
Werncke found it moi-e active from that point of view than boric acid.
Its antiseptic and bactericidal capacity is, however, very weak. Kuhn
found that it only acted in 2 per cent solution. Schwartz, however,
found that the bacteria of the infusion of tobacco were exceptional,
and that a 0*5 per cent solution had already a certain effect on these
microbes. Wenckiewicz found that it had no action on PenictUium
glaucum until its solution reached 1-1 per cent. Borax exerts a
poisonous action on plants. By watering haricots with a very dilute
solution of borax Peligot first induced chlorosis, then death.

Use. — Borax has been recommended in 5 per cent solution in
America against the Peronospora viticola, De By. (mildew of the vine).
At that strength it can circumscribe that disease, but its use is not

110 INSECTICIDES, FUNGICIDES, AND WEED KILLEKS.

without drawback, for it burns the leaves of the vines treated. Care
should be taken to wash these a few hours after treatment. Muhlberg
found borax solutions did not kill the Scliizoneura lanigera, Hausm.,
against which it had been recommended.

29. Carbonate of Soda, Na2C03. — Preparation. — By the Solvay
(Brunner, Mond) process principally. A concentrated solution of
common salt is first saturated wdth ammonia, then a prolonged current
of carbonic acid is passed through ; bicarbonate of ammonia is pro-
duced, which acts on the common salt to convert it into carbonate of
soda. The precipitate is filtered, drained, and calcined.

Properties. ^Carbonate of soda crystallizes in prisms ; the crystals
lose their water of crystallization at the ordinary temperature. Heated,
they melt in their water of crystallization, dry, and form calcined
carbonate of soda (soda ash), which is an amorphous white powder
containing no water. Soda crystals are much more soluble in hot
water than in cold : the maximum solubility is at 38° C. ; one gallon of
water dissolves 6-04 lb. at 14° C, 166-6 lb. at 38° C, and 44-5 lb. at
104" C. Carbonate of soda in solution has a strong alkaline reaction.

Action of Carbonate of Soda on Plants. — Around alkali works
the presence of this salt, carried by the wind, does much damage.
Eventually the carbonate of soda, covering the leaves with a white
layer, more or less thick, causes them to drop off, and kills the trees
themselves. Eye suffers much from contact therewith ; the ears are
almost empty, and the few grains which they contain are shrivelled
and blackish. When plants have been in contact with carbonate of
soda the analysis of the ash reveals a quantity of soda superior to the
normal quantity. The straw of cereals is more brittle, and contains
less silica. Carbonate of soda acts like carbonate of potash ; when it
is a case of neutralizing the acidity of certain marshy lands carbonate
of soda may play the part of lime, and the nitric ferments, which
cannot act except in slight alkaline media, may thereby modify the
flora of the field. In such conditions carbonate of soda, in small dose,
may exert a favoural)le influence on vegetation.

Action on Fungi.- — -Wuthrich treated the spores of different fungi
with sodium carbonate with the following results : A solution of 0'05S
per cent prevents the conidia of the Phytophthora injestans, De By., from
producing zoospores, but it does not injure their direct germination ;
life is only arrested by immersing the conidia in a 0*53 per cent
solution As to the conidia of the Peronosj)ora viticola, De By.,
Wuthrich found sodium carbonate more energetic ; a 0*053 per cent
solution hindered the growth of the spores, and a solution of 0'53 per
cent stopped it entirely. The uredospoi-es of Puccima graminis, Pers.,
show, more than any other spores, a great resistance to carbonate of
soda solutions, l)ut gei'inination is hindered by 0-53 per cent solution
and stopped entirely by immersion in a 2"65 per cent solution.

Action on Insects. — All soft-skinned insects are sensitive to
strongly alkaline substances, but these substances in themselves are
not very powerful insecticides ; they are, therefore, combined with toxic
substances.

Use. — Carbonate of soda enters into the composition of certain

SODIUM CARBONATE. Ill

copper bouillies, but it has no other function than to decompose the
blue vitriol into carbonate of copper and sulphate of soda. An excess
of carbonate of soda must be avoided in the preparation of Burgundy
or cuprosodic bouillies, because these evaporating on the leaves may'
give rise to the same bad effects as carbonate of soda and cause the
leaves to drop. Carbonate of soda has also been recommended
against plant lice, and chiefly against the woolly aphis, but Muhlberg
has shown its inefficacy. According to Delacroix one of the best
emulsions to use against lice is carbonate of soda 10 lb., soft soap
20 lb., petx'oleum 1 gallon, in 10 gallons water.

Note by Translator, re Arsenite of Soda, p. 108. — This substance is made a
speciality of by at least one firm in Great Britain who sell it in a more or less con-
centrated state of solution. Several "accidents" have occurred from the solution
having been drunk inadvertently, and some deaths occurred through leakage of a
cask on to sugar casks during transit. What is known in medicine as Fowler's
, solution is a solution of arsenite of soda.

CHAPTEE VII.

POTASSIUM HYDROXIDE (CAUSTIC POTASH)— POTASSIUxM SULPHIDES
(LIVER OF SULPHUR) — POTASSIUM CHLORIDE (MURIATE OF
POTASH)— POTASSIUM NITRATE— POTASSIUM SULPHOCARBONATE
— POTASSIUM XANTHOGEN ATE— POTASSIUM CYANIDE (PRUSSIC
ACID)— POTASSIUM SULPHOCYANIDE.

30. Caustic Potash, KHO. — Preparation. — By decomposing
carbonate of potash in solution in water by lime a precipitate of carbonate
of lime is formed, and potassium hydroxide enters into solution : —

K,C03 + Ca(OH), = 2K0H + CaCOg

Potassium Calcium Potassium Calcium
carbonate, hydroxide. hydroxide carbonate.

Properties. — Caustic potash is a white deliquescent solid ; exposed
to moist air it absorbs water and carbonic acid. Potash, even in dilute
solution, is a strong caustic which softens and gradually dissolves the
skin ; it traverses and perforates the mucous membranes ; it is a
strong poison, which should be handled carefully. It is used in
surgery as a cautery. [Antidote, vinegar.]

Use. — Potash solutions have been used in America against different
plant lice, which, owing to the chitinous protections covering them,
greatly resist insecticides. The caustic nature of potash gives access
to the insect by removing these obstacles.

Psylla Pyricola, Forst. (psylla of the pear). — Slingerland tried to
destroy the eggs of this insect, but, contrary to anticipation, caustic
potash had not the desired effect. BoUey tried this substance to de-
stroy potato scab, but found that a 0"5 per cent solution injured the
formation of the eyes and germs, and that in 1"5 per cent solution it
almost completely destroyed them.

31. Potassium Sulphides, K.^S to K^S^. — Preparation. — Potas-
sium monosulphide is prepared from caustic potash ; by saturating a
30 per cent solution with hydrogen sulphide, potassium hydrogen sul-
phide and water are formed : —

KOH + H.S = KHS + H,0.

The same amount of 30 per cent caustic potash is afterwards added,
which reduces the hydrosulphide to the monosulphide : —

KHS + KOH = K.,S + H2O.

To obtain the polysulphides it suffices to heat the monosulphide with
1, 2, 3, 4 atoms of sulphur.

(112)

POTASSIUM SULPHIDE (LIVEE OF SULPHUR). 113

Liver of Sulphur is a mixture of polysulphides, but it contains
especially the pentasulphide of potassium. It is preferably obtained
by heating to redness in a crucible equal parts of sulphur and car-
bonate of potash. By the action of heat the carbonic acid is disen-
o;aged and the sulphur combines with the potassium. When the
disengagement of carbonic acid is finished, the liquid is run on to an
iron plate where it solidifies immediately ; it is then broken up and
preserved out of contact with air. It forms a reddish- brown solid
which smells of rotten eggs.

Properties. — The sulphides are very deliquescent and soluble in
water in all proportions. They must be kept out of contact with air ;
carbonic acid in presence of moisture rapidly decomposes them into
potassium carbonate and hydrogen sulphide. Solutions of the mono-
sulphide are colourless, those of polysulphides, on the other hand, are
yellow. Sulphides retain the alkaline properties of caustic potash,
attenuated by sulphur. In medicine, sulphides are used to treat skin
diseases due to acarium. Plants do not stand spraying with sul-
phide solutions, these being generally used very dilute. The sul-
phuretted hydrogen given off by decomposition is poisonous to the
plant in a 0'75 per cent dose, but it is only formed gradually, so that
the amount in contact with the plant is not sufficient to cause any
ill effect. Leaf burning is less frequent than with sublimed sulphur.

Use. — Sulphides are used to combat : (1) Cryptogamic diseases,
either by spraying the plants or by immersion to disinfect the seed
against anthracogenic parasites. (2) To kill insects. To impart more
adherence and a longer action, a soap and glycerine emulsion is used.
Polysulphides of potassium are used in the same proportion as sulphur,
for they decompose under the action of carbonic acid and air and or-
ganic acids into potash salts, hydrogen sulphide, and sulphur : —

K^Ss + CO, + H,0 = K.COg + H,S + 4S.

The sulphur is precipitated in a fine state of division, and thus its
anticryptogamic properties are at a maximum. It can thus be said
that the action of polysulphides is appreciably identical with that of
■ sulphur, and especially of precipitated, impalpable sulphur if used in
the same temperature conditions. In studying their application it
will be seen that they have entered into current practice as substitutes
for sulphur in killing numerous ErysijjJiecB and to stop the develop-
ment and extension of certain fungi by the destruction of their co7ii-
diophores. In sulphides the caustic action aids that of sulphur. Not
only do sulphides have a decided action on fungi and their spores,
but the potassium carbonate formed by their decomposition has a de-
cided action on fungi, whose growth it prevents. The growth of conidia
of phytophthora and of peronospora is stopped by a 0"7 per cent solu-
tion, their zoospores being no longer able to develop. The spores of
Ustilago Garho and of Claviceps furpurea as well as the uredospores
of Puccinea are more resistant than the former, for a 0'7 per cent solu-
tion hardly hinders their growth, whilst a 3-5-7-5 per cent solution
stops it.

As insecticides, sulphides act in virtue of their caustic properties,

114 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

and the sulphuretted hydrogen given off by their decomposition, this
gas being for insects almost as poisonous as, prussic acid. It is, more-
over, asserted in medicine that sulphides used in 5-20 per cent solution
in skin diseases, such as itch, act on the parasites by the sulphuretted
hydrogen formed in contact with the organic acids of the transpiration
and the carbonic acid of the air.

Use against Bacteria. — Sulphides retard putrefaction and kill
microbes (Amsler). It has been tried to utilize this property to
treat plant diseases of bacterian origin, such as potato scab. The
bacteria which causes this disease of the potato is found, according to
Bolley, in the living tissues of the periphery of the tubers and never
penetrates deeply; it is aerobic. Bolley has submitted tubers so
attacked for twelve hours to the action of a 0"3-0"4 per cent
solution of potassium sulphide before planting them. At that strength
the causticity of the sulphide is not sufficient to injure the tubers. An
appreciable effect was obtained, but the sulphide has not the radical
effect of mercury bichloride. The results obtained by the sulphide are
still defective — 5 per cent of healthy tubers against 1 per cent in a
blank field.

Gum Disease of the Olive (Mai di Gomma of the Italians). — Swingle
and Weber advise to combat this disease by potassium sulphide : 18
kilogrammes (39*6 lb.) of potassium sulphide are dissolved in 15 litres
(3"3 gallons) of water; to this paste 12 kilogrammes (26'4 lb.) of 98 per
cent caustic soda are added and energetically stirred. The mass
heats, boils, and melts. As soon as boiling is over the bulk is made
up to 100 litres (22 gallons) with water. The cankers and wounds
formed by the disease are cleaned, diluted before use with an equal
bulk of water ; the roots, even sound ones, are stripped and watered with
a solution of this sulphide in 10 parts of water.

Use against Fungi. — Pickling of Seed=Corn. — Dilute solutions
of potassium sulphide prevent the growth of fungi and their spores and
may kill them if of a certain strength. The action of the sulphide is
not the same on all spores, e.g. it is almost nil on the spores of
PJt>jto2}hthora Phaseoli, Taxter. (Lima bean mildew). Hitchcock
and Carleton remarked that a 1 per cent solution not only did not
destroy the uredospores of Puccinia graminis, Pers. (black rust) and
Puccinia coronata, Corda (coronated rust of oats), but rather acceler-
ated their germination. By numerous experiments on rusts Gallo-
way came to the same conclusion. The disinfection of grain in 0"75
per cent solution made no diminution in the rust. By spraying
winter wheat no appreciable result was obtained unless spraying
with a 0'5 per cent solution was repeated every ten days. Under
such conditions he obtained 1 diseased plant against 24 in the blank
plot. If twenty days' interval occurred between the sprayings the rust
did not diminish but the harvest was a little better. Kellermann and
Swingle were the first to observe the sensitiveness of the spores of
smut to sulphide, especially the loose smut of oats. Jensen tried if
grain could not be disinfected by sulphide against smut. The results
which he obtained were surprising, and he did not hesitate to advise it
in place of steeping in hot water recommended by him some years

POTASSIUM SULPHIDE (LIVEK OP SULPHUR). 115

previously. The powder used in the beginning and known under the
name " Ceres," is nothing more than potassium sulphide. The
numerous experiments of Bolley, Rostrup, and Selby show, however,
that the sulphide is not capable of rendering better services than the
Jensen hot- water treatment or that of Kuhn's \vith blue vitriol or that
by mercuric chloride. It generally gives very irregular and some-
times imperfect results, for example, against Smut of Wheat (Eostrup).
It has, however, a serious application in the disinfection of oats, where
it is superior to any other treatment in destroying the spores of
Ustilago AveiicB, Eost. (loose smut of oats). This treatment is practised
in Denmark where it is highly esteemed. Steeping should last twenty-
four hours in a 0"75 per cent solution.

Helnmithosporium gramineum, Eriks. (black mould of cereals). —
Kolpin Kavn found steeping grain in the sulphide is a good precaution
against this disease.

Spraying with Dilute Solutions. — The Erysiphece,ihe my ceWnm.
of which is not protected by the tissue of the plant attacked, may be
combated by potassium polysulphides. Owing to their decomposition
the sulphur is deposited between the filaments spread on the surface
of the organs attacked, and acts in a more certain manner than sulphur
used against the same disease. In spite of their properties the
sulphides of potassium are not used to combat the oidium. Gardeners
use them against Microsphara Grossularice, Wallr. (gooseberry leaf-
mildew) ; Sphcerotheca Mors Uvce, B. et C. (American gooseberry
mildew), which they cure radically. Close prefers a 0-3 per cent solu-
tion of potassium sulphide to the fungicides, usually employed by sol,
formol, and bouillie bordelaise. Golf advises spraying with a 0"2 — 0"4:
per cent solution as soon as the leaves appear, and to renew it after
each heavy rain until the plants are completely in leaf, and from time to
time in summer. He obtained the following results : The fruit garden
check plots showed 11-3 per cent diseased plants, after 0-2 per cent treat-
ment 7 per cent, and after 0-4 per cent 1-7 per cent of diseased plants.

Sphmrotheca pannosa, Lev. (rose and peach mildew). — This fungus
may be combated efficaciously by potassium sulphide. Vesque recom-
mends spraying with 1 per cent solutions, Mohr 2 per cent liver of
sulphur, to which he adds 2 per cent of glycerine to render it more
active and adherent. A concentrated bouillie is prepared by dissolving
200 grammes of liver of sulphur and 200 grammes of glycerine in a
litre of water (say 2 lb. of each in a gallon of water) and the solution
kept out of contact with air until required for use, when it is diluted
with ten times its bulk of water.

Spharotheca Gastagnei (hop mildew). — Salmon recommends 0"1
per cent solutions, Selby 0*2 per cent solutions.

Amongst the fungi living in the interior of plants which cannot be
reached, a certain number may be combated by destroying the conidio-
spores which contribute to their rapid propagation. These are :—

Alternaria BrassiccR f. nigrescens, Peglion (scorching of the leaves
of the melon). — Sturgis used potassium sulphide with much success.

Spharella Fragarioe, Sacc. (spotting of the leaves of the straw-
berry).— Potassium sulphide has been used successfully in America by

116 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Butifum and Arthur against this parasite of the strawberry to prevent
its too great extension.

Guignardla Bidivellii, Viala et Eavaz (black rot). — Galloway ob-
tained satisfactory results with O'l per cent solutions of liver of
sulphur: blank vines 65'64 per cent of sound grapes; vines sprayed
six times, 75'17 per cent of sound grapes. This treatment cannot
compete with that of copper salts, because notwithstanding its less
efficacy it is not quite harmless to the vine leaves.

Septoria Piricola, Desm. (spotting of the leaves of the pear). —
Duggar used potassium sulphide with success, but found it less
efficient than bouillie bordelaise.

Cladosporiicm fulvum, Cooke (tomato disease). — The mycelium,
which extends between the cells of the parenchyma, cannot be reached,
but the conidiophores maj' be destroyed. Liver of sulphur acts better
than sulphur in this instance (Mohr).

Gloesporium frutigenum, Berk, (bitter or tardy rot of fruit). — To
prevent this, Galloway and Nijpels spray the apples before maturity,
in August, with a 0*4 per cent solution.

Fusicladiwm dentriticum, Fuckel (apple scab) ; Fusicladium piri-
num, Fuckel (spoLs of the pear). — Gaff found that on apple-trees
frequently sprayed with 4 per cent solutions of liver of sulphur from
the birth of the leaves, and renewed after each heavy rain, the amount
of diseased apples is appreciably diminished.

Use against Insects. — Potassium sulphide may be used as a
caustic against delicate insects. It also destroys the tissues protecting
grubs.

Acridides. — Dubois observed the great sensitiveness of grasshoppers
(Locusta) and their eggs to potassium sulphide. These eggs touched
by solutions of potassium sulphide do not hatch. Watering the soil
with potassium monosulphide on the spot where the Acridides have
laid their eggs may suffice to impede the invasions of the Acridium
migratorium so formidable in Algeria.

Ertocampa adumbrata, Kl. (the pear-tree saw-fly). — Taschenberg
recommends powdered fresh liver of sulphur spread like sulphur on
the trees. Solutions of the sulphide are used with success against the
caterpillar protected by a silky tissue which render them inaccessible
to ordinary aqueous insecticides. Potassium sulphide by its caustic
action softens and finally decomposes the tissues, and penetrates to the
caterpillar which then dies owing to the sulphuretted hydrogen dis-
engaged.

Gonchylis ambignella, Hubn. (cochylis of the vine). — Schmidt-
Achert recommends as very efficacious against this caterpillar a 2-5
per cent solution of liver of sulphur sprayed on the flowers and on
the grapes ; Schafer, on the other hand, did not obtain good results by
this treatment.

Hyponomeula Malinella, Zell. (hyponomeute of the apple-tree). —
Bach found a bouillie made with 1200 grammes of soft soap and 200
grammes of liver of sulphur in 100 litres of water (say 121b., and 21b.
in 100 gallons of water). This bouillie can be used with success
against all caterpillars that live in company in a spun refuge.^

POTASSIUM CHLORIDE (MURIATE OF POTASH). 117

Tingis Piri, Fl. (Tigre du Poirier). — Montillot recommends two or
three coats with the brush in winter, at intervals of a fortnight, on the
branches and trunks of pear-trees with a preparation made thus : 2 lb. of
potassium monosulphide is dissolved in the requisite amount of water ; it
is withdrawn from the fii'e and 2 lb. of flowers of svdphur gradually added.

Plant Lice. — Moss recommends a mixture of soap and liver of
sulphux-, known in England as Chiswick compound, against lice in
general. Thumen regards 2^ per cent solutions of potassium sulphide
as good. The phylloxera is absolutely refractory to the action of
potassium monosulphide. Mouillefert tried it against that parasite by
spreading 480 grammes per stock in a radius of 30 centimetres round
root-stripped vines, and sprinkling them with 10 litx'es of water (2*2
gallons). As a matter of form, the following curious process, recom-
mended by Ponsard, may be quoted : It consists in boring a hole with
a gimlet into which 2-3 grammes of potassium sulphide was introduced ;
the hole was then closed with mastic. The author of this process hoped
that the sulphide entrained by the jus would induce the death of the
phylloxera, but this treatment has only given a negative result.

Phytoj^tides. — The acari, which by irritation of the tissues of the
plant produce degeneration of the latter, become manifest by felt-like
growths known as erinoses or by peculiar swellings of bright-coloured
tints as is seen on the pear when it has the Cloque (brown rust), may
be destroyed by the sulphides. Emulsions containing 3-4 per cent
of sulphur must be used at the moment when the acari have not yet
produced the excrescences which protect them so efficaciously. Smith
and Williamson advise to treat chiefly the Eriophyes Piri, Pgst., Phy-
toptus Piri, by two sprayings, one before the opening of the buds, and
the second after collecting the fruit, or even spraying with a concen-
trated emulsion in winter followed by a weaker one after plants have
come into leaf.

32. Potassium Chloride (Muriate of Potash), KCl ; Potassium
Sulphate, K^SO^. — Natural Occurrence. — Potassium chloride is
found (500 grammes per cubic metre) in sea- water. Potassium
chloride and sulphate of potash form vast underground deposits at
Stassfurth in Prussia and at Kalusy in Galicia. In these mines the
different salt beds have a different composition. Below vast deposits
of rock salt deposits rich in sulphate of potash are found under the
form of triple sulphate of lime, magnesia and potash (Polyhalite),
then sulphate of magnesia and potash {Kainite), and finally double
chlorides such as Carnallite. Carnallite, for example, contains 16
per cent of potassium chloride, 20 per cent of magnesium chloride,
25 per cent of sodium chloride, 10 per cent of magnesium sulphate,
and 29 per cent of impurities. For agricultural purposes these salts
are generally used in the impure state as brought from the mine. If
it be desired to purify them and to obtain pure potassium chloride, the
saline mass is pulverized and dissolved in large cast-iron steam-heated
vessels. The solution is allowed to deposit, then decanted, and left to
crystallize ; the potassium chloride crystallizes, entraining with it a
little magnesium and sodium chlorides which are removed by washing
with cold water. If potassium chloride be treated with sulphuric acid,

118 INSECTICIDES, FUNGICIDES, AND WEED -KILLEES.

which is dooe commercially in cast-iron vessels, hydrochloric acid is
given off and potassium sulphate formed.

Properties.— Potassium chloride is very soluble in pure water.
320 grammes dissolve in 1 litre of water at 10° C, 570 grammes in 1
litre at 100^ C. Potassium sulphate is less soluble, a litre of pure
water dissolves 84 grammes at 0° C. and 260 grammes at 100° C.

Action on Plants. — Potash is a necessary plant food. In soils
where potash is quite absent plants languish and finally die before
maturing their seed. Such soils are rare. They are such as contain
a large proportion of limestone, peat, or sand. Potash may be given
to the plant as potassium chloride as well as the sulphate or nitrate.
The crude salt from the mines is generally used for the purpose. If
soil be dissolved by aid of sulphuric and hydrofluoric acids, and if the
potash which it contains be isolated, enormous amounts are found per
hectare. The German agronomists calculate this amount at 30-40
tons per hectare (12-16 tons per acre). Berthelot found 35 tons
at Meudon (14 tons per acre) and Deherain 32 tons at Grignon
(12"8 tons per acre). This potassic mass is not in a state of soluble
chemical combination, but it may be dissolved by the acid juices
of the roots which it appropriates in sufficient amount. When potassic
manures are added to soils of this nature, and they form the great
majority, no benefit accrues to the plant, and the spots where they are
applied cannot be recognized, no increased yield being obtained.
Potassium manures are only useful as a supplementary material when
the soil does not contain it in any form. Then its influence makes
itself felt especially when the crop is sustained by other chemical
manures such as sulphate of ammonia, nitrate of soda, and super-
phospate. Farmyard dung which contains 5 kilogrammes (11 lb.) of
potash per ton, suffices with the (potash) salts contained in the soil to
meet the requirements of agriculture. The belief of the great efficacy
of potash salts in all soils, established by Liebig, has not been con-
firmed in practice. An excess of potash salt may, on the contrary, be
injurious to certain plants. Heinrich was the first to observe the
injurious effects of certain salts, such as potassium chloride and
magnesium chloride, nitrate of soda and sulphate of ammonia on ad-
ventitious plants. Steglich has specially studied the action of potas-
sium chloride on farm crops with the following results : —

TABLE XVIII. — Shoicing the Action of a ^(i per cent Solutioji and a 15 per cent
Solution of Potassium Chloride (Mtiriatc of Potaslt) oyvFarm Crops.

Crop.

30 i)er

cent

Solution.

15 jH'r ce7it
Solution.

Crop.

30 ^;<'?' cent
Solutiofi.

15 2Jer

cent

Solution.

Grain .

Beets .
Potatoes
Peas .

Haricots
Trefoil

Injurious
fleetinfj;

Nil
Deadly

Nil

Disappears

in 5-8 days

Nil

Deadly

Sli-ht

Nil

Lupins

Flax

Mustard .

Charlock .

Korrel

Poly^oniuni

Morwe-tail

Deadly

^^

Very injurious

Deadly
Injurious

Deadly

Nil

Slight

Nil

POTASSIUM CHLORIDE (MURIATE OF POTASH). 119

On the other hand, a 6 per cent solution of kainite has no injurious
effect on the most tender part of the plant.

Use. — As Pickle for Seed-Corn Smut. — G. Arieti tried to
disinfect seed-corn against smut by steeping it for twenty-four hours
in a 0"5 per cent solution. At that strength potassium sulphate
has no injurious action on the germination of the grain, but neither
is its action on the spores very pronounced. A 2 per cent solution
renders the spores of Tilletia (bunt) inactive, but the seed already
suffers. G. Ville, having observed that a want of potash in the
soil seems to favour the development of the PhytopJithora infestans,
De By. (potato disease), recommended the use of potassic manures to
combat it in a preventive manner. Care must be taken, however,
not to use larger quantities than 600 kilogrammes per hectare, saj'
528 lb. per acre, for at that dose potash salts diminish the yield in
starch. These salts are also employed against phanerogamic parasites,
such as dodder.

Cuscuta epithymitm, Murray (dodder of trefoil and lucerne). —
Their sensitiveness to metallic salts is very great, and these parasites
may be easily destroyed by watering the fields with such solutions.
In the same way as the sulphates of iron and copper, green and blue
vitriols, which give good results, the sulphate of potash may als')i)e
used. Vesque recommends to dust with this product in a heavy
morning dew the plots invaded by dodder. Next morning, after this
treatment, the fields of trefoil and lucerne present a lamentable appear-
ance ; all the plants are brown and look as if burned, but the effect of
sulphate of potash on leguminos* is only fleeting, and in eight days
these plants have resumed their vitality, whilst the dodder is destroyed
to such an extent that it does not reappear the following year. The
dose to use is from 200-250 grammes per square metre, say 7-8
oz. per square yard.

Equisetum arvense, L. (meadow horse-tail). — This plant, which
contains aconite, is injurious to cattle. Tacke advises, to free crops
infested with it, to water them with a concentrated solution of
potassium sulphate ; the gramineae can resist this treatment, whilst
the horse-tails died.

Heterodera Schachtii, Schm. (nematode of the beet). — As a sequel
to Liebig's researches, concluding that potash is a necessary food of
this plant, it was observed that potash salts used in beet growing, up
to a certain dose, remedied the exhaustion of the soil. Kuhn sided with
the general opinion that such salts acted by their nutritive properties
and replaced the potash removed by the beet. Webster and Hopkins
still hold this opinion and deny the insecticide action of potash salts.
But after it was found that the exhaustion of the land by this crop
was due in great part to an excessive growth of small worms,
nematodes, Hollrung tried the action of potash salts on their larvae.
He remarked that the latter, more sensitive than the adults, died in
forty-eight hours in a 1 per cent solution of potassium chloride and in
three hours in a 5 per cent solution. Potassium sulphate is less
active in a 1 per cent solution as it takes ninety-six hours' immersion
to destroy the larvte, and has the same toxicity as potassium chloride in

120 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

a 5 per cent dose. To succeed, the dose used must be considerable ;
instead of using pure sulphate, the double salts from the mines, kainite
or carnallite are used, but these are less active than the pure salts.
Hollrung has observed that in big doses these salts are unfavourable
to the formation of sugar in the beet. There are no great advantages
in using potassium chloride or sulphate in massive doses to remedy
the exhaustion of the land, for the effect is somewhat illusory. This
practice has moreover been abandoned since, as the outcome of Aime
Gerard's researches, arable land may be sterilized by large doses of
carbon disulphide.

Agriotes lineatus, L. (striped wire-worm). — Comstock and Slinger-
land ascribe insecticide properties to potassium sulphate against the
adults. Smith regards a 12 per cent solution of kainite as an excellent
insecticide. But Marlatt, who used big doses of kainite, against wire-
worm (Elaterides, click beetles), got no appreciable result. Mineral
manures such as potash salts injure certain parasitic larvae, e.g. : —

Lachnosterua fitsca, Frohl (May beetle) ; Lachnosterna arcuata. —
Chittenden found kainite very active. Possibly the larvse of the
Elaterides which are very mobile flee from soils which have been
treated with big doses of potash manures. Opinions are too contra-
dictory to admit that potash salts kill them.

Agrotis segetum, W. V. (common dart moth). — The grey worm,
the caterpillar of this butterfly, is driven off or destroyed by watering
the infested spots by a 12 per cent solution of kainite.

Jassus sexnotatus, Fall. — Steglich uses kainite in a composition to
combat this grasshopper: kainite 10 lb., carbolic acid 1 lb., soft soap
10 lb., in 100 gallons of water.

Snails. — Kainite is a specific against snails (Taschenberg).

33. Nitrate of Potash, KNOg. — Occurrence. — Nitrate of potash,
or saltpetre, occurs in nature ; it is found in the great plains of China,
India, and Egypt. It is extracted by removing the nitrated earth for
a few centimetres and lixiviating it. The liquor is then run into large
basins and evaporated in the sun.

Preparation on the Large Scale. — By double decomposition of
sodium nitrate and potassium chloride. By hot concentration of the
solution the sodium chloride formed crystallizes, whilst the saltpetre,.
much more soluble when hot than common salt, remains in solution
and does not deposit until after cooling.

Properties. — Saltpetre is very soluble in water, 10 gallons of water
dissolve 15 lb. of saltpetre at 9° C, 85 lb. at 15° C, 246 lb. at 100° C.
(212" F.), 335 lb. at 118° C. At a great heat [igneous fusion] salt-
petre is a powerful oxidizing agent.

Action on Plants. — Potassium nitrate like potassium chloride is-
a plant food, and what has been said anent potash salts applies to-
potassium nitrate.^ Concentrated solutions injure plants.

Action on Fungi and their Spores. — Wuthrich's researches on
the action of metallic salts on the s))ores of fungi also include potassium

' Translator'' K Noi('. — But the nitric acid is the predominating agent of potas-
sium nitrate, and as a plant food puts it beyond comparison with other potash salts,,
thf, phoHphate excepted.

POTASSIUM NITRATE. 121

nitrate. The growth of the conidia of Phytophthora infestans, De By.,
is not stopped by an 01 per ceijt solution, but the formation of zoo-
spores is prevented. The growth of the conidia is not hindered until
a 1 per cent solution is used. The zoospores are at once killed by
this solution. The spoi-es of Peronospora Viticola, De By., are a little
more sensitive. A O'Ol per cent solution hinders their growth a
little ; with a 0"1 per cent solution the conidia cannot form zoospores.
Their motion is slackened, and after fifteen hours none reach their
normal growth ; a 40-4 per cent solution interferes with the growth
of Ustilago Garho (smut), a 50"5 per cent solution stops it. A 50-5 per
cent solution lowers the vitality of the spores of Puccinia gramims,
Pers., but they are only killed with a 101-1 per cent solution. A 101
per cent solution does not destroy the vitality of the spores of Claviceps
purpurea (ergot), Tul. Nitrate of potash therefore, even in strong
doses, is deficient in real anti-cryptogamic properties. It has no toxic
action, but merely exerts an unfavourable effect on the development
of the spores by producing plasmolysis. Like many substances,
potassium nitrate acts as an astringent when it is used in concen-
trated solution. As such it may prevent all cryptogamic evolution,
but that is all its effect. If the spores, the growth of which has been
momentarily suspended, are washed and replaced in good conditions,
they generally develop normally.

Use. — Nematus Bibesii, Scop, (gooseberry and currant saw-fly) ;
Abraxas gross ular lata, L. (the magpie moth). — Taschenberg uses
against these two gooseberry pests a spray of a 1*2 per cent solution
of nitrate of potash.

34. Carbonate of Potash, K0CO3. — Preparation. — The impure
commercial potash is obtained by incinerating terrestrial plants. This
incineration is done where there are many forests and where the
means of transporting wood are difficult. The ashes obtained, which
do not contain more than 5-20 per cent of carbonate of potash,
are washed in casks and are exhausted after three or four washings.
The collected liquors are evaporated and yield the salt which calcined
in contact with air furnishes commercial potash, consisting mostly of
carbonate of potash with a small amount of potassium sulphate and
chloride.^

Properties. — Deliquescent. Dissolves in its own weight of water.
Eeaction strongly alkaline.

Action of Carbonate of Potash on Plants. — Used in agriculture
carbonate of potash by its alkalinity plays the role of lime, i.e. it
corrects the acidity of the soil and utilizes the nitric ferments which
can only work in a slightly alkaline soil. The nitric acid so formed
increases the crop. Carbonate of potash can thus greatly alter the
flora of an acid meadow. The reeds and rushes of the acid land dis-
appear to the benefit of the useful gramineae and leguminoste. This

' Translator''s Note. — Fabulous amounts of potash are produced in Eussia by
the incineration of sunflower stalks, and a big trade is done both with London and
New York in such potash. But as Fritsch well points out, to grow any plant as a
source of potash would be to go round in a vicious circle (see Fritsch's "Chemical
Manures," Scott, Greenwood & Son, which gives a detailed description of all GermHii
potash mineral salts).

122 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

sensitiveness of plants belonging to the Cyperaceae and the reeds has
been often remarked , and this product is utilized to destroy them. Noffray
spreads wood ashes on meadows in wet weather or after a strong dew ;
the reeds and the rushes are burned and the leguminosae grow rapidly.
The injurious action of carbonate of potash is not limited to these
plants alone, it is very decisive on dodders, mosses, and lichens.
The first are destroyed by spreading wood ashes on the clover fields
in dry weather and watering afterwards. The result is satisfactory,
but it cannot be compared to that got with green vitriol, for there often
remains after treatment some immune parts which contribute to the
propagation of the disease. Carbonate of potash may replace lime
against mosses and lichens. Sorauer replaces the common process of
liming the trunks of trees by coating them with a solution of 15 lb. of
carbonate of potash in 15 gallons of water. This treatment not only
frees the tree from the parasites sheltered under the fissures of the
bark but does not colour the tree white like lime.

Action on Fungi. — Alkaline carbonates have no toxic action on
spores of fungi, but at a certain strength they impede their growth.
Tillet who observed this action found it sufficient to guarantee the
seeds of black wheat. Disinfection by the lye from wood ashes has
given appreciable results.

Plasmodiophora Brass lea, Woronine (finger and toe). — As a pre-
ventive, Nijpels waters with carbonate of potash against the finger
and toe so as to kill the spores of the myxomycetes and prevent infec-
tion of young plants.

Action on Insects. — Soft- skinned insects are generally very
sensitive to alkaline substances and may be combated therewith.
Soft soap and lime are of great service ; carbonate of potash acting
similarly has been recommended by some observers.

Crioceris Asparagi, L. (the asparagus beetle). — The larvae of
this Coleoptera is very delicate and may be destroyed by spraying
with the lye from wood ashes.

Haltica (ground flea beetle). — To prevent these voracious Coleoptera
from gnawing the young plants growing in the fields in the spring,
Montillot spreads wood ashes on the seed beds. It is chiefly against
the different species of plant lice that carbonate of potash has been
found useful.

Schlzoneiira Lanlgera, Hausm. (the woolly aphis or American
blight). — Taschenberg uses lye from wood ashes to destroy this insect,
but Muhlberg found this method ineffective.

Phylloxera vastatrix, Planch. — Mouillefert found potassium carbon-
ate ineffective.

Aspidiotus 2)erniciosa (San Jose louse). — Marlatt made numerous
attempts to destroy this apple bug so formidable in America, and ob-
tained with 24 lb. of lye in iO gallons of water, 85 per cent lice killed ;
with 12 lb. 75 per cent ; with G lb. 50 per cent ; with 3 lb. 20 per cent.
Carbonate of potash in itself acts injuriously on the lice, and as it is at
every one's disposal it may be tried in certain cases. But it will act
more suiely if it be used as an aid to certain toxic substances,
petroleum, for example. Alkaline products, in fact, act on the mucus

POTASSIUM SULPHOCARBONATE. 123

and the chitin so as to let the toxic substances reach the parasite and
act on it more rapidly.

Wood ashes are also utilized to kill slugs, using preferably that from
lime-kilns, as it still contains lime, the action of which aids the carbon-
ate of potash. After a rain in the evening the ashes are spread broad-
cast on the seed beds of whatever nature ; it exerts no injurious action
on the plant but kills snails instantly on touch. It is well to water
the plants next morning and recommence the treatment after sunset.
In vineyards where slugs are dreaded vines are heavily dusted with
ashes.

35. Potassium Sulphocarbonate, KoCSaH^O. — Preparation. —
By agitating potassium monosulphide K.,S, with an excess of carbon
disulphide. If a pure px'oduct be not desired liver of sulphur may also
be used.

Properties. — Carbon disulphide acts as an acid towards alkaline
sulphides and forms compounds therewith analogous in constitution to
the alkaline carbonates K^SCS^.

But these compounds are unstable ; the moisture and carbonic
acid in the air decompose them thus —

K2CS3 + COo + H.O = K.COg -f CS, + H.2S

into alkaline carbonate, carbon disulphide, and sulphuretted hydrogen.
Organic acids act in the same way. This decomposition goes on
slowly in the air and in the soil, according to the moisture of the sur-
rounding media and the richness in carbonic acid. The dry crystals
contain 38 per cent of carbon disulphide and can disengage 17 per cent
of sulphuretted hydrogen ; 100 grammes of 40'' B. commercial solution,
which tests 55 per cent of pure potassium sulphocarbonate, can give
off on decomposition 20 per cent of carbon disulphide, say 6 litres, and
9 per cent of hydrogen sulphide, say 6 litres. Potassium sulpho-
carbonate is in the solid condition a yellow crystalline very deliquescent
body. But it is very difficult to obtam in that form, and the commercial
article is liquid and marks 35^-40^ B. It is soluble in water in all
pi'oportions. [Alkaline sulphocarbonates treated by hydrochloric acid,
then taken up immediately by water, yield a reddish-brown insoluble
liquid which represents sulphocarbonic acid ; it is used in therapeutics.
It readily decomposes into CS.2 and H^S. The sulphocarbonates which
chemically contain carbon disulphide have no analogy with the sulphide
mixed with tar, vaseline, oil, or soap, the use of which has been pro-
posed to replace the pure sulphide.]

Action on Plants. — Sulphocarbonate when concentrated is a
violeut plant poison. The two gases [CS^, and HoS'i which it liberates
are likewise poisons, but their action is less energetic than that of the
sulphocarbonate itself. Trials on healthy vines in 3-litre pots at
different seasons of the year show that the vine is more sensitive in
summer during the activity of the sap than in winter. Thus in
August, vines do not stand a dose of 12 cubic centimetres of 10° B. with
or without water, whilst a dose of 15 cubic centimetres may be given
in winter, and even in April when already the vine has big buds. Now
15 cubic centimetres of sulphocarbonate of 40° B. can only disengage 3

124 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

grammes of carbon disulphide and 1'35 gramme of sulphuretted
hydrogen, quantities which are supported by the vine in similar condi-
tions, especially in emulsion in water. It takes more than 6 cubic
centimetres of sulphide emulsified in 60 cubic centimetres of water to
kill the vine at that period. Young adventitious plants {Mercurialis
annua, Polygo7ium aviculare, Calendula arvensis, Borrago officinalis,
Erodium cicutarium, Ictaria viridis) vegetating in the open air were
treated at end of August with 100 cubic centimetres of sulphocarbonate
of potassium or sodium of 45° B., reduced so as to make 2 litres of
mixture, and spread in five holes in a square of 20-inch side ; the plants
only suffered in the immediate neighbourhood of the holes. Haricots
planted in pots containing 2 litres of soil resist perfectly when
watered with 250 grammes of a 2 per ceat solution of 45° B. potassium
sulphocarbonate. Now, in practice, such strong doses are never used
against insects. The toxic effect of potassium sulphocarbonate on
plants is therefore almost negligible, whilst the dose is always poisonous
to insects in a 0'0005 per cent solution.

Action on Fungi. — Like carbon disulphide potassium sulpho-
carbonate in strong doses exerts an injurious action on the mycelium
of fungi and their spores. Dufour and Mouillefert tried this com-
pound to replace carbon disulphide against root blight, Dematophora
necatrix, Hartig. They did not, however, obtain the good results
which they anticipated. Dufour only registered 15 per cent of cures
after treating the stocks of vines suffering from the blight by a 2 per
cent solution at the rate of 3-5 litres per stock. It is true, that in
these trials Dufour is far from having fed into the soil a dose of 150-
200 grammes of carbon disulphide per square metre, as is the case
in the treatment of root blight by carbon disulphide, for the 100
grammes of liquid sulphocarbonate used in this case only contained
15 grammes of sulphide. Sulphocarbonates cannot replace the sulphide
in the treatment of root blight, for they are much dearer. It is only
when the dose of sulphide is minimum, as in the case of some insects,
that the sulphocarbonates present real advantages over carbon di-
sulphide.

Action on Insects. — Sulphocarbonates, owing to their composi-
tion, are almost equally as efficient as potassium cyanide. The most
dilute solutions have a manifest and rapid action on insects. Mouille-
fert examined very exactly the limit of action of sialphocarbonates
used against the phylloxera in different ways.

1. By contact. — By dipping the insects into dilute solutions, 1 in
200 of sulphocarbonate of 38° B., the insects were found dead in a
quarter of an hour ; in 1 in 500, in one hour ; in 1 in 1000, in one
hour fifteen minutes ; in 1 in 5000, one hour ; in 1 in 10,000, two hours
fifteen minutes; in 1 in 100,000, in twenty-four hours. In a blank
flask only containing water the insects were not dead in twenty-four
hours. The potassium sulphocarl)onate of 38° B. used in these trials
not containing 50 })er cent of dry sulphocarbonate, it may be said that
the action of this pi-oduct is deadly to the phylloxera in twenty-four
hours in a 1 in 200,000 solution, say 0 0005 per cent of dry salt.

2. By the toxic vapours disengaged by the decomposition of the

POTASSIUM SULPHOCAKBONATE. 125

sulphocarbonates. In a 2-litre flask with moist sides into which
-^ cubic ceatimetre of sulphocarbonate of potash of 40" B. had been
run, the phylloxeras of an infested root suspended in this flask were
killed in three hours. By running in 4 cubic centimetres of this pro-
duct the insects were killed in half an hour. Now ^ cubic centimetre
contained 0'354: of dry sulphocarbonate capable of emitting by decom-
position 0"l-4 gramme of carbon disulphide, or 40 cubic centimetres,
and 0'06 gramme of sulphuretted hydrogen, or 40 cubic centimetres
of gas, giving a total of 80 cubic centimetres of poisonous gas. It may
therefore be concluded that ^ cubic centimetre of sulphocarbonate is
capable of producing in 2 litres of air an atmosphere with 4 per
cent of toxic gases.

In trials with ^ cubic centimetres of sulphocarbonate, or with 100
cubic centimetres of a O'l per cent solution, capable of producing 16
cubic centimetres of poisonous gas, and consequently an atmosphere of
0"8 per cent, the insects were killed in twenty-four hours. Now it is
admitted that sulphuretted hydrogen destroys the phylloxera in twenty-
four hours when the air contains 1 per cent of this gas, and carbon disul-
phide when the atmosphere contains O'O per cent of its vapours. It
has been seen that the sulphocarbonate of potash disengages the same
volume of these two gases. It follows that a mixture of equal volumes
of sulphuretted hydrogen and carbon disulphide in the gaseous state
would kill it in twenty-four hours with a solution of 0"75 per cent
strength. The result obtained is thus appreciably the same as that
found for sulphocarbonate of potash. The mixture of the two gases
produced by the decomposition of the sulphocarbonates kills the
phylloxera in the same time as a mixture of the same quantities of
these two gases acting simultaneously. But sulphocarbonates do not
act only when they eater into decomposition, their solutions are in
themselves powerful insecticides. Whilst both gases produced by the
decomposition do not kill the phylloxera except at 0-0015 per cent
the sulphocarbonates in solution kill at 0*0005 per cent. Sulpho-
carbonates may thus be regarded as the most powerful of disinfectants,
their aqueous solution being three times more powerful than
sulphuretted hydrogen gas and carbon disulphide. Owing to this
property, alkaline sulphocarbonates may be used to distribute through
the soil substances highly poisonous to insects. There is no difference
in the action of the different salts of sulphocarbonic acid, potassium
sodium, or calcium salts, but the former are generally used because they
possess the advantage of carrying into the soil a certain amount of
potash, which, in certain circumstances, may contribute to the rapid
reconstitution of the damaged root system. The doses used in the
laboratory to kill the phylloxera are not those which are of use on the
large scale, because many causes contribute to reduce their efficiency.
The doses tried by Mouillefert were at first very strong, and killed
the vine, treated as well as the parasites. The soil was watered
from small vats near the stocks with a solution of 400 cubic centi-
metres of sulphocarbonate of potash of 38° B. in 5 litres of water,
then with 8 litres of pure water. In other cases he used 220 cubic
centimetres of sodium sulphocarbonate of 45° B. dissolved in 4 litre of

126 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

water, distributed in four holes 60 centimetres deep placed in a radius of
35 centimetres around the stocks. The dose of 20 cubic centimetres
of sulphocarbonate of 33° B. su£&ced to kill the phylloxera without
injuring the vine, but it is preferable to use per stock 50-80
centimeti'es of sulphocarbonate at 37'2° B. dissolved in 10 litres of
water to obtain complete success.

Use. — Sulphocarbonates were examined so as to be utilized in
vine-growing in the destruction of the phylloxera. The results
obtained against this louse by snlphocarbonation led to this treatment
being tried on other insects on which it has also given good results.

Phylloxera Vastatrix, Planch, (phylloxera of the vine). — History. —
In the semice of 8 June, 1874, Dumas proposed the sulphocarbonates
for the destruction of the phylloxera, indicating at the same time a
practical method for their manufacture. The Department of Agri-
culture and the. 4 cacZeww'e des Sciences entrusted therefore two delegates,
Cornu and Mouillefert, to make the necessary experiments to de-
termine if the predictions of the learned chemist would be realized.
Mouillefert made numerous experiments at the Cognac Viticultural
Station, and was able to conclude that the sulphocarbonates, and
especially potassium sulphocarbonate, were marvellous insecticides and
also the best remedy against the phylloxera. In his remarkable re-
search on the chemical products proposed for the destruction of
the phylloxera he places the sulphocarbonates in the first rank
of efficiency, and declares them to be alone capable to keep a vine
attacked by the phylloxera in a thriving condition, and to regenerate it
if weakened by the disease.

In numerous experiments on vine stocks placed in different condi-
tions of soil, age, and cultivation, the sulphocarbonates always effected
an improvement. Those greatly attacked by the phylloxera had lost
all their root hairs, and of which a part of the radicles was attacked
were, after a year's treatment, finer plants than the non-diseased stocks.
The stocks still more badly diseased and almost in the last extremity
were appreciably improved and did not die like the untreated blanks.

Mouillefert in 1876 published the conditions which it is indispens-
able to observe to secure good results by this treatment. The useful
application of alkaline sulphocarbonates to the cure of the vine re-
quires : (1) That all the infected surface be treated. (2) That the
poison be injected deep enough to reach all the phylloxera. The best
method to secure perfect diffusion in the soil is to use water as the
vehicle. The amount used may be greater, or less, according to the
state and conditions of humidity in the soil, and according as it may be
expected to rain, or not, but water cannot be completely suppi-essed.
The more water added, the more complete the diffusion and rapid the
action. The amount of sulphocarbonate required to treat a square
metre to a depth of 80 centimetres, 31*2 inches, which gives 800 litres,
gay 1 cubic yard, of soil, is 30-40 cubic centimetres, 1-lJ fluid oz.,
which is comparatively very little. Without the aid of water it would
be very difficult to distribute this small volume on the surface of the
soil and equally impossible to cause it to descend to a sufficient depth
to kill all the insects unless the soil be very permeable or rain falls at.

POTASSIUM SULPHOCAEBONATE. 127

a propitious moment, which is exceptional. In all cases the direct
use of water suffices if the quantity be abundant, whether the soil be
compact, stony, or permeable, diffusion is always perfect. Alkaline
sulphocarbonate solutions of 1 in 10,000 and even 1 in 20,000 being
still poisonous in cultivation on the large scale, too great dilution need
not be feared, in rendering diffusion more perfect, to make the remedy
impotent. The best method of using sulphocarbonates consists in
making flat receptacles in the soil, round the foot of each vine, and
there distribute the poison. For this purpose 500 kilogrammes per
hectare (440 lb. per acre), say 50 gi-ammes per square metre, are
diluted in 350 times its weight of water. After having poured the
solution into the excavations it is well to pour on a little water to
cause the poison to penetrate more deeply. When all the water is
absorbed by the soil, the ground is put back into the pit and tramped
down under foot. Sulphocarbonates may be used at any time of
year, for the small dose has no effect on the plant, but it is prefer-
able to use them whilst the sap is at rest. The water required to
carry the poison into the depths of the soil being sometimes an
obstacle to its use in many districts, the most convenient time for the
application of sulphocarbonates is, then, that when rain is most
abundant during winter, when the soil is already saturated with
moisture. For small or medium scale cultivation, the best plan con-
sists in placing the amount of sulphocarbonate required for a stock,
say 50 grammes (1| oz.), in a 10-litre (2'2 gallon) watering-can, then
to pour into each pit the entire contents of this watering-can, and
afterwards pour an entire watering-can full of water on each stock.
But it is preferable when possible to make a dilute solution in a lai-ge
reservoir, and to draw out with the watering-can the amount required
for each stock. On the large scale, Mouillefert and Hembert have
designed plant intended to bring the water required for the treatment
into vineyards. It consists of a steam engine, working suction and
propelling pump which can send the water several kilometres, and to
a height of 100-150 metres (328-492 feet). The pump, placed near a
river or a lake, sends the water into a distributing channel forming a
network of ramifications through the vinejard. The channels of the
third order end in metallic vessels of 350-400 litres (77-88 gallons) in
which the sulphocarbonate is dissolved ; the workmen there draw the
amount of insecticide required, and spread it with the watering-can
around the stocks. With good organization the workmen need not carry
the water more than 10 metres, say 33 feet. A man can then spread
1500-1800 litres, say 330-896 gallons, of water an hour round the vines.
By this ingenious process, vines far from a source of water may be
treated. But owing to the large amount of water required, which is
150,000 litres per hectare, say 60,000 litres (13,200 gallons) per acre,
being awanting in many districts, this treatment has not been adopted
everywhere. Its use also finds a drawback in the fact that the cost of
sulphocarbonating is greater than sulphuring. It costs in fact 300-350
francs per hectare (120-140 francs, £4 16s. -£5 128. per acre). It is tnie
that it brings potash to the value of 50 francs per hectare, 16s. an acre,
on to the land, but that is only really useful in districts where potash is

128 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

deficient. Sulphocarbonates have therefore their place only in rich
vineyards like those of Champagne, Burgundy, and Bordeaux. They
should be preferred to carbon disulphide, the more so as they are much
less dangerous for the vine. A^ Poex justly remarks, it is a process to
use in de luxe vineyards. There are in France vineyards that have
been submitted to this treatment for fifteen years, and still in good
condition. In France there are hardly more than 10,000-12,000
hectares (25,000-30,000 acres) treated annually by sulphocarbonates,
and since the carbon disulphide treatment has been better studied
this figure has a tendency to diminish, for the carbon disulphide treat-
ment, like the sulphocarbonate, being annual the small doses of sulphide
used in such conditions are not prejudicial to the vine and enable it to
be kept in a good state of production. Unfortunately, whatever care be
taken in applying these substances there will always be a certain
number of phylloxera which escape the toxic action. If, theoretically,
the sulphocarbonates are capable in small closes of entirely destroying
the insects on the roots, it is not so in practice even in much stronger
doses ; different causes prevent the result from being so complete. But
by the treatment the number of the phylloxera is so reduced as to
enable the root hairs formed during the fine weather not to be entirely
destroyed, and for the plant to nourish itself on the revival of vegeta-
tion. If the evil be not entirely removed it no longer forms an obstacle
to the vine maintaining its vigour. The important point is to diminish
the parasites, so that the vine may live with them without the crop
suffering. The use of water as the vehicle of the sulphocarbonate
being the great obstacle to the propagation of this marvellous insecticide,
it has been tried whether mixtures with slaked lime would not likewise
bring about a uniform distribution of the sulphocarbonates in the soil.
It was Dumas who advised Mouillefert to try these mixtures, hoping
that the lime, before its transformation into, carbonate, would absorb
the carbonic acid of the air and prevent the sulphocarbonate decom-
posing rapidly. In this way a powder would be got easily spread in
the soil at the foot of the stocks, which would preserve the alkaline
carbonate intact whilst waiting for rain to carry it into the neighbour-
hood of the infected roots. Mouillefert, therefore, mixed 500 cubic
centimetres of sulphocarbonate of potash of 37° B. with 1*2 kilo-
grammes of lime in powder and spread this mixture in winter at the
foot of five stocks, previously stripped to the big roots on a radius of
35-45 centimetres ; the earth was then put back into the holes. A
fortnight later after a series of heavy rains the roots were examined ;
on all the top roots the insects were dead, but on the roots more than
40 centimetres (say 6 inches) the insects were not found dead until
two months afterwards. Success would have been complete if it had
not been that on the I'oots beyond the stripped radius the phylloxera
were still living. According to the predictions of Dumas, the use
of sulphocarbonate in these conditions may suffice, provided the
mixture be spread all over the vineyard. To attain this object the
proportion of lime must be increased greatly, and a mixture of 500
kilogrammes of sulphocarbonate with 5000 kilogrammes of slaked
lime aj^plied per hectare of vineyard (say 440 lb. and 4400 lb., 2 metric

POTASSIUM XANTHOGENATE. 129

tons per acre). After spreading it would suffice to hoe the ground so
as to mix it with the earth and protect it from contact with the air
which would decompose it. From Laugier's experiments it would
appear possible without hurting the vine gradually to extinguish the
hotbeds of phylloxera infection, by aid of repeated mixed treatments
of sulphocarbonate of potassium and carbon disulphide, applied op-
portunely and in suitable doses. This process, much used in Switzer-
land and Italy, appears to leave nothing to be desired.

Disinfection of Vines and Graft Bearers. — Sannino advises for
this purpose sulphocarbonate of potassium in O'Oo per cent solution;
for disinfection to be complete immersion must last two hours.
Dufour recommends for the disinfection of graft bearers coming from a
phylloxera district the steeping of these in a solution of the following :
sulphocarbonate of potash O'O per cent ; soft soap 5 per cent; pyrethra
powder 1 per cent ; tobacco juice 1 per cent.

Carpocai^sa jjomonella (Pyrale du Pommier) (the codlin moth) ;
Carpocapsa funehrana, Fr. (? Carcocapsa nigricane) (the red plum
grub). — Montillot recommends watering the soil at the foot of the trees
in autumn, after collecting the fruit, with a solution containing 1 per
cent of sulphocarbonate potassium.

Gonchylia ambignella, Hubn. (cochylis of the vine). — Dufour tried
to combat this insect by spraying with sulphocarbonate, but he did not
kill the caterpillar. A bouillie containing 1 per cent of sulphocarbon-
ate and 3 per cent of soap destroyed the insects but scorched the buds,
which browned and finally dropped off. A 0'l-0'05 per cent solution
does not injure the plant and kills all underground larvae.

Formica (ants). — An excellent means of destroying an ant-hill con-
sists in the use of sulphocarbonate. A small trench is dug round
the ant-hill and it is watered in the morning as. far as possible, w^hen
the ants have not yet gone out, with an 0"5 per cent solution. Half
a litre to a litre of this solution suffices to destroy an ant-hill. After
absorption of the liquid it is well to beat the earth down.

Galeruca calmariensis (galeruca of the elm); Galeruca Alni
(galeruca of the alder). — Sulphocarbonates in solution applied in
August destroy these insects so injurious to the trees in our parks
and public promenades. [See p. 137.]

36. Xanthogenate of Potassium, C^H-OCSSK.^ — Definition. —
This compound is the potassium salt of the ethylic ether of dithio-
carbonic acid, OHCSSH.

Preparation. — By acting with an excess of carbon disulphide on
absolute alcohol saturated with caustic potash. The crystals of
xanthogenate of potassium formed abundantly are washed with
ether.

Properties. — Xanthogenate or ethyl sulphocarbonate of potassium
forms colourless or slightly yellowish needles ; they are soluble in water,
likewise dissolving in 5-6 parts of absolute alcohol. The decom-
position of the aqueous solutions into carbon disulphide, ethyl alcohol,
and potash begins at a temperature of 25" C. (77" F.), to be completed
on boiling. Xanthogenate of potassium stops rermentation like carbon
disulphide and coagulates albumen. Schwartz found that the action

9

130 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

of its solutions on bacteria and ferments do not commence except at
the temperature at which this salt decomposes, and that it only there-
fore possesses the disinfectant action of carbon disulphide. But this
does not in any way detract from its valuable properties as an antiseptic,
since carbon disulphide acts on bacteria in aqueous solution at 0'5 per
cent and that this product contains 47 per cent of carbon disulphide.
In medicine xanthogenate of potassium has found different uses.
Lewin recommends it against helminthiasis and for different affections
of the skin.

Use. — Xanthogenate of potassium may be used in all cases where
carbon disulphide and sulphocarbonate of potash have been found
useful. Its solubility in water is greater than that of carbon disulphide
and its stability in air more perfect than that of sulphocarbonate of
potassium. Its properties would have assured it a much higher place
in agricultural medicine if its price were not higher than similar com-
pounds. Yet in spite of its high price xanthogenate of potassium is
used in disinfection and enters into the composition of certain insecti-
cides.

Phylloxera vastatrix, Planch, (phylloxera of the vine). — Dr.
Koenig, director of the Agronomical Station of Nice, has made very
extended trials of the action of this salt on phylloxera, and found that
compared with carbon disulphide and sulphocarbonate of potash its
value as a disinfectant of phylloxera-infected vines was greater and
more certain. The eggs and phylloxeras are killed without exception
by submitting them to the action of solutions of xanthogenate of potas-
sium or to that of the vapours which its solution emit on heating.
To disinfect the roots Koenig recommends the use of aqueous solu-
tions. The disinfection of ornamental plants suspected of phylloxera
and intended for export is carried out at the Nice station by Koenig's
process alone.

Schizoneura lanigera, Hausm. (woolly aphis). — Muhlberg recom-
mends to combat the woolly aphis an insecticide known as knadolin,
which whilst preserving the properties of Nessler's contains two most
active substances, nitrobenzene and xanthogenate of potassium. Amyl
alcohol 60 lb., soft soap 40 lb., nitrobenzene 2 lb., xanthogenate 1 lb.,
water 6 gallons. Knadolin in 2 per cent solution kills the greater
number of insects injurious to plants. To apply it the wounds and
cankers caused by the American wooU)'' aphis are coated with a solu-
tion of 1 part of this insecticide in 15 parts of water.

37. Potassium Cyanide, KCN. — Preparation. — Potassium
cyanide is formed each time that carbon and nitrogen come in contact
at a high temperature with an alkali or an alkaline carbonate. Com-
mercially potassium cyanide is prepared by submitting nitrogen or
•organic bodies rich in nitrogen to the action of carbon impregnated
with potash and heated to redness. Prussic acid or hydrocyanic acid
is generated by the action of an acid on potassium cyanide. The
latter, however, does not cede all the hydrocyanic acid which it con-
tains.

Properties. — Potassium cyanide crystallizes in deliquescent cubes ;
it is found in commerce as fused white plates which must be kept out

POTASSIUM CYANIDE (PRUSSIC ACID). 131

of contact with air because that decomposes it rapidly into hydrocyanic
acid and carbonate of potash —

2KCN + H.O + CO, = K.COg + 2HCN.

The commercial product is never pure, it always contains a greater
or less amount of carbonate of potash. Prussic acid is a colourless,
very volatile liquid having the odour of bitter almonds. It is, like its
salts, a dreadful poison. The vapours given off by decomposition in
contact with air kill the insects and animals which breathe it in a few
minutes. Its action is the same in whichever way it be intro-
duced into the body, by digestion, respiration, or introduced into the
blood through a wound. A drop of hydrocyanic acid placed on the
eye of a dog causes it to die in a few seconds a dreadful death. The
respiration of the vapours of this acid induce giddiness, then death.
The mortal dose for a man is 0"06 gramme, say 1 grain, of prussic
acid and 0"15 gramme, say 2j grains, of potassium cyanide. According
to Preyer, prussic acid acts through the compounds which it forms
with the haemoglobin and the oxyhaemoglobin of the blood.

Action on Plants. — All cyanogen compounds have a poisonous
action on plants, but it is prussic acid which possesses this property
in the highest degree. As far back as 1827, Goppert remarked that
prussic acid prevented the germination of grain, and absorbed by the
plant it killed it in one to three days. When a plant is watered with a
dilute solution of cyanide the latter is absorbed and distributed through-
out all parts of the plant by the sap ; the leaves turn yellow, then brown,
and the turgescence of the cells of the parenchyma is abolished.
Perosino succeeded in injecting a very dilute solution of potassium
cyanide into the trunk of a tree without hurting it, and after two days
all trace of this product had disappeared in the sap, but the dose to be
withstood was, it is true, infinitesimal. Berlese has shown that trees
withstand these injections badly, even in small doses. Mouillefert made
a very complete examination of the action of potassium cyanide on
vines and adventitious plants.

Ex'periments made in July on Healthy Vines, variety Saint Emilion.
— Placed in pots, each containing 3 litres of soil, three vine stocks
were watered with (1) 170 milligrammes of cyanide, say a 0'142 per
cent solution ; (2) 250 milligrammes of cyanide in 140 cubic centi-
metres of water, say a 0-18 per cent solution ; (3) 500 milligrammes of
cyanide dissolved in 180 cubic centimetres of water, say a 0'28 per
cent solution. In six days vine No. 3 was dead, that carrying No. 2
was greatly inconvenienced, and No. 1 seemed to suffer. As will be
seen from these results the substance is highly poisonous to the vine, as
a dose of 0*008 per cent of potassium cyanide in the soil kills this plant.
Guerrieri estimates that a dose of 1 gramme suffices to kill an adult
vine, and that it is impossible to kill the phylloxera by this method, the
vine being as sensitive as the parasite. The fact that the phylloxeras
of a vine treated with cyanide die mainly by the absorption of the
poisoned juice, shows that this method of treatment must bo as per-
nicious to the vine as to the phylloxera ; Chittenden considers that it
is impossible to treat all plants by hydrocyanic acid vapours to free

132 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

them from plant lice ; the acid may, however, be used without fear
on Davallia, Adiantwn, Coleus, Viola, Bosa, Diantus, Vitis, and
Lycopersicum. It is necessary to try each variety of plants to see if
this method of treatment can be successfully adopted against the
caterpillars without risk to the plants themselves.

Experime7its made in July on Adventitious Plants. — The experi-
mental ground was a square with side of 50 centimetres and contained
young plants about fifteen days old {Mercurialis annua, Polygonum
avicidare, Amarantus hlitum, Borago officinalis, and Erodium cicutar-
ium) ; 500 milligrammes of potassium cyanide, dissolved in 400 cubic
centimetres of water, say a solution of 0"125 per cent, was distributed
in five deep holes of 15-20 centimetres. In the morning all the young
plants were dead. After six days nothing remained alive but two
stocks of Borago and one stock of Erodium.

Action on Fungi. — Few trials have been made. Hitchcock and
Carleton immersed the uredospores of Puccinia graniinis in a 0*1 per
cent and a 0*01 per cent solution. The first solution prevented
germination. The second had no effect.

Action on Insects. — Potassium cyanide, also the prussic acid given
off from it in moist air, are insecticides of extraordinary power, an in-
finitesimal dose killing insects in a few minutes. Its action is more
energetic than that of sulphocarbonate of potash, sulphuretted hydro-
gen, and ammonia. It acts on insects by respiration and through the
stomach. Entomologists use it to kill the insects which they catch.
Mouillefert submitted different insects to the action of this poison,
especially the phylloxera, which he specially examined. One gramme
of potassium cyanide was placed in a 250 cubic centimetre flask. The
following are the results obtained with the different insects introduced
successively into the flask : A butterfly died in four minutes ; a dragon-
fly in ten minutes ; an earwig in ten minutes ; a plant louse is annihi-
lated in less than two minutes ; a stag beetle in four minutes ; and a
grasshopper in less than two minutes.

In Ameilca potassium cyanide is a specific for the destruction of
certain plant lice ; it is to be observed, however, that their eggs with-
stand doses usually sufficient to kill the adult insects. According to>
Coquillet it is chiefly the Diaspines, amongst which must be counted
Aspidiotes, Diaspis, Lecanium, Ceroplastes, Cochineal, which are most
sensitive to prussic acid. Whilst almost all insects succumb when
they respire a weak doze of prussic acid, there are some which are-
indifferent to this poisonous gas : these are certain Coccinella, the red
spider {Acarus telarius) of Linneus {Tetranchus telarius, L.) ; th&
Schizoneura lanigera, Hausm. (woolly aphis) ; and some flies of the
family of Proctotrupidu3 of the genus Alaptus. The danger of the
prussic acid treatment is an obstacle to its becoming general, the more
so as there are less dangerous substances, which, in the same conditions,
are of equal service. There are, however, certain cases where prussi©
acid is superioi- to these products. When it is a question of destroying
one of those plant lice covered with a chitinous carapace, ordinary
insecticides which do not reach the insect musi be set aside, because
they cannot reach it. Emulsions of petroleum, amyl alcohol, benzine,,

POTASSIUM CYANIDE (PRUSSIC ACID).

133

and carbon disulphide, with soft soap, only yield imperfect results.
It is otherwise with prussic acid ; its vapours, owing to their poisonous
nature, can destroy the best protected insects through the respiratory
organs, and as easy as any soft-skinned insect. In America the
benefits of the substance have been recognized, and it is in constant use
by farmers. To-day all fruit growers use it with success, and owing
to potassium cyanide used rationall}^ in winter, fruit trees are freed
from all their parasites. In America apple-trees have been particu-
larly the prey of the San Jose louse, but potassium cyanide, which has
played in this case the role of carbon disulphide in the phylloxera in-
vasion, has enabled this dangerous cochineal to be circumscribed and
efficiently combated.

Use. — In spite of its toxicity and the danger incidental to its use,
potassium cyanide is in current use in certain countries ; it is, in fact,
the most radical and the cheapest means to destroy tree parasites.
Cyanide can only be used in a closed space. Its decomposition is
hastened by the addition of dilute sulphuric acid. This practice
requires great precautions, because the prussic acid given off is as
deadly to the operator as to the insects. When a greenhouse is not
at disposal the operation is done under cloches for small plants, and
under tents for trees. The latter are of packing cloth, impregnated
with linseed oil and ochre, or wax. These portable tents are generally
hexagonal in shape and must touch the ground on all sides ; they are
closed hermetically by beating down the soil on the edges of the cloth.
In America they use exclusively large cubes with a wooden frame-
work covered with packing cloth. In this manner trees as high as
20 feet may be treated. To disinfect a tree the tent is placed over it,
and then a solution of potassium cyanide is run into a terrine to which
dilute sulphuric acid is added, taking care to place this terrine quickly
under the tent and to retire. The following, according to Debray, are
the quantities to use for 5 cubic metres of air : 30 grammes of 58 per
cent potassium cyanide dissolved in 50 cubic centimetres of water,
35 grammes of sulphuric acid of 66° B. (168° Tw.) diluted' with 50
cubic centimetres of water, and, according to Coquelin, the doses of
potassium cyanide to use according to the size and force of the tree : —

TABLE XIX. — Shotcing the Amount of Potassiwn of Cyanide, Water, and Snl-
phuric Acid to Use in Cyaniding Trees of Different Heifjht and Diameter.

Height.

Diameter.

Potassiiim.

S^dphuric

A.cid.

Water,
c.c.

Metres.

Feet.

Metres.

Feet.

Grammes.

Grains.

Grammes.

Oz.
Av.

3

9-84

2-50

8-20

65

997

130

65

2-3

3-50

10-48

3C0

9-84

130

1994

250

130

4-5

8-50

10-48

4-50

14-76

250

3835

500

250

8-7

4-25

13-94

3-00

9-84

160

2454

350

160

4-25

13-94

3-50

10-48

210

8222

500

210

4-75

15-58

4-25

13-94

340

5216

750

340

5-50

17-08

4-25

18-94

425

6521

850

425

134 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

The action is complete in a quarter of an hour (Dubray), three-
quarters of an hour (Eitzema Bos), and five hours to destroy kermes
(Eeh). Johnson says that disinfection is complete in a veiy short time,
and that with ten appai-atus, 200 trees may be disinfected in a day, the
operation lasting half an hour. A method much in vogue in America
consists in disinfecting the roots of young nursery plants as far as the
crown. For this purpose all the trees are dug up, and placed in
closed cupboards or chambers in which prussic acid is disengaged ;
10,000 young trees can be disinfected in this way at a time. Dr.
Koenig has introduced the practice of this style of disinfection at the
Agronomical Station of Nice, where it is employed for vines, ornamental
plants, as well as the branches of ornamental plants intended for ex-
portation. Waite and Howard recommend for the disinfection of
purchased trees hermetically sealed cupboards, in which they are en-
closed for an hour in an atmosphere of prussic acid before replanting ;
although the majority of plants resist the action of these poisonous
vapours it is preferable to operate during the repose of vegetation, for
in that condition they resist stronger doses capable of destroying the
parasites and their eggs. The action may be prolonged, and even last
an hour. The result is only the more complete. Tuille recommends
for the destruction of the larvae of the cockchafer {Melolo7itha vulgaris,
L.) to plough in colza or mustard during the flowering season along
with a ton of gypsum or lime per hectare (8 cwt. per acre). Amongst
the poisonous gases given off in consequence of the fermentation of
these plants is sulphuretted hydrogen, but also a certain amount of
prussic acid.

Scolytides. — In America prussic acid is regarded as an excellent
substance for destroying the insects which dig galleries in the trunks
of trees. It may be applied at the moment the Scohjtides or the
Bostriches attack the young trees.

Wasjos. — Gardner recommends the use of a solution of 120 grammes
in a litre of water (1-2 lb. per gal.). A plug of waste is attached to
a rod dipped in this solution, then introduced into the orifice of the
nest of wasps. The effect is instantaneous.

Nematus Bibesii, Scop, (gooseberry saw-fly). — The highly voracious
larvae of this saw-fly ai'e destroyed in Canada by cyaniding, working
under small tents as ah'eady mentioned. The gas acts in fifteen
minutes. To destroy the butterflies injurious to cotton plantations,
Mally plants haricot beans between the rows. As soon as the latter
are in flower they are sprayed with a dilute solution of potassium
cyanide. That kills the butterflies which settle on the flowers.

Carpocapsa jjoriionella (the codlin moth). — It is in winter that
fumigation under a tent with prussic acid may be very eflectual. The
process is in common use in Canada.

Diplosis riolicola, Coquillet (violet fly). — Chittenden advises treat-
ing the violet stocks with potassium cyanide, so as to kill the larvae of
this fly.

Phylloxera vastatrix, Planch, (phylloxera of the vine). — Experi-
mentH on the phylloxera action by contact. — A phylloxera-infected root
was immersed for two minutes iu a 1 per cent solution of potassium

POTASSIUM CYANIDE (PEUSSIC ACID). 135

cyanide ; the phylloxeras and their eggs were all dead when it was
liited out.

Experiments on Phylloxera : Fumigation. — Five milligrammes of
potassium cyanide, yielding by decomposition 1'7 cubic centimetres of
prussic acid vapour, were placed in a flask of 2100 cubic centimetres,
then a phylloxera-infected root. When the action was complete the
atmosphere of the flask consisted of 8 parts of prussic acid vapour
per 10,000 parts of air. After fifteen hours there were no living
insects. It follows that potassium cyanide is about ten times more
poisonous than potassium sulphocarbonate, for it suffices for an
atmosphere to contain 0*08 per cent prussic acid gas to obtain the
same result as with 0"75 of a mixture of equal parts of sulphuretted
hydrogen and carbon disulphide, disengaged from potassium sulpho-
carbonate. Under a cloche 0000240 of potassium cyanide kills plant
lice.

Experiments on Phylloxera : Action by Poisoning. — A phylloxera-
infested root was immersed by its extremities in a 0-l2o per cent
solution of potassium cyanide with the precautions necessary to hinder
the phylloxera being exposed to prussic acid vapours. After ten
minutes' treatment the adult phylloxera, the nests of which were sunk
in the tissues of the root, were dead, the greater number of the larvae were
alive. The cyanide can thus poison the sap, and in that way reach
the phylloxeras fixed on the roots. Mouillefert having shown that
potassium cyanide acted in a very poisonous manner on the phylloxera,
and that an infinite quantity killed these insects either by contact or
by poisoning the sap, the substance may be regarded as of gi'eat
service in agriculture.

1. Experiments on Phylloxera-infected Vines, in pots containing
3 litres of earth, on 10 July. A dose of 150 milligrammes of KCy
in 400 cubic centimetres of water (a 0'0375 per cent solution) gave a
complete result without injuring the vine, whilst a dose of 500 milli-
grammes in 500 cubic centimetres water caused it to suffer greatly.
A dose of 1 gramme in the same amount of water killed it.

2. Experiments on Vines in Vineyards, made on 6 -July. The
stocks were stripped to a depth of about 15 centimetres, with a radius
of 30-35 centimetres (12-14 inches), the soil being rather dry. After
pouring on the potassium cyanide solution the soil was replaced at the
foot of the stocks and strongly packed. The dose used varied from
20-50 grammes (307-767 grains) per stock, dissolved in 10 litres (2-2
gallons) of water. Wherever the solution had penetrated, the phylloxera
and their eggs were dead. But at a depth of 40-45 centimetres (16-
18 inches), as well as between the stocks in a radial direction, even by
using five times more water the result was incomplete. Trials with
the pal-hole method gave no better results, and Mouillefert concluded
that potassium cyanide was incapable of producing a complete result
in agriculture on the large scale, because its action is only felt where
the solution can penetrate. The prussic acid disengaged in the soil
cannot diffuse through its layers like carbon disulphide, neither does
F. Guerreri believe it possible to use this substance against the phyl-
loxera, for he found that the plant did not resist the doses required

136 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

to kill it, and that a dose of 1 gramme of cyanide, say 15 grains,
per stock was capable of injuring it. Attempts to replace carbon
disulphide by potassium cyanide, more especially in Italy, have given
unfavourable results.

Disinfection of the Vine. — Whilst potassium cyanide has been
abandoned in the different cases described above, this product is used
with success to disinfect vines intended for exportation, or coming
from a contaminated country. This process, introduced at the Nice
Agronomical Station by Koenig, yields perfect results. It is in common
use, moreover, in Tuscany. Sannino advises to replace the disinfectant
chambers by baths containing a 0"o per cent solution, and in which
the vines are immersed in winter for two hours. The same process is
used to destroy cochineal on fruit trees.

Diaspines {Diasjnnece). — Coquillet uses prussic acid as a specific
against diaspinecB, cochineals (scale insects).

This product may be used against all these dangerous parasites, of
which the following are the chief : Aspldiotus perniciosus, Comstock
(San Jose louse), injurious to apple-trees in America. Asjndiohis ostrea-
formis, Curtis. Oyster scale, very widely distributed on apple-trees,
plum-trees, pear-trees, and peach-trees. Aspidiotus aurantU, Maskell.
Cochineal injurious to orange-trees. Diasjns ostreaformis, sign. s.
fallax, Horvath. Cochineal injurious to apple, pear, plum, and peach
trees. Mytilaspis p)omorum, Beche. Mussel scale, resembling the pre-
ceding and living on same plants. Lecanimn persicce (peach kermes) ;
Leccmiiim hesperidium (olive kermes) ; Pulvinaria vitis (vine cochi-
neal) ; Gerejilastes rtisci (iig cochineal) ; Dach/lopius citri (lemon-tree
cochineal) ; Lecanium amygdcdi (almond-tree cochineal). Coquillet,
Johnson, Webber, Wait, and Howard, American entomologists, are
unanimous in praising the good effects of the use of potassium cyanide,
and that insecticide is in current use in their country. So that the
result may be complete, the treatment should last three-quarters of an
hour, and the operation done in winter as indicated above.

Earth-worms are less resistant than plants to spraying with a dilute
solution of potassium cyanide and they may be got rid of by this
means.

38. Potassium Sulphocyanide, KCNS. — Preparation.- — Sulpho-
cyanides are produced by the action of sulphur, or a body capable of
producing sulphur, on cyanides. Potassium cyanide, or even yellow
prussiate, fused with sulphur is converted into potassium sulphocyanide
thus : 46 grammes of yellow prussiate are heated to pasty fusion with
17 grammes of potash and 32 grammes of sulphur ; after cooling, the
mass is crushed, treated with boiling alcohol, filtered, and evaporated.

Properties. — If sulphocyanide has certain analogies with cyanide
it is far fi'om being as poisonous. It paralyses the action of the heart
(CI. Bernard and Pelikan).

Action on Plants. — Mouillefert treated several plants with
KCNS:—

(1) Exp)eriments on Adventitious Plant Weeds. — In a space 16
inches square on which there were youug plants of Mercurialis annua,
Amarantus hlitum, Senecio vulgaris, Sonchus oleracetis, Polygonum

POTASSIUM SULrHOCYANIDE, l'^7

.aviculare, Mouillefert placed in six holes, 6 grammes say 91 grains, of
KCNS, dissolved in a litre of water (6 parts in 1000 . Next morning
all the young plants were dead. The adult plants had suffered greatly _

(2) ExpeHments on Healthy Vmes in Po^-Half a gramme of
KCNS in 250 cubic centimetres water (1 in 500) and spread round the
stock killed it in five days. KCNS thus has a very injurious action on
plants, an action almost equal to potassium cyanide. As it does not act
bv its vapours, its action on the plant depends solely on the permeability
•of the soil for its solutions. This explains why equal doses do not always
produce identical effects. The same ^PPli^^, ^^ f q^\Xl ' 'tZn°i
all stable salts. Kranch treated barley with (NH,)CNS, and found
that a 1 per cent solution killed this plant. .

Action on Fungi.— Sulphocvanides do not act like cyanides
(Hitchcock and Carleton). A 1 per cent solution used in immersion
for twenty-four hours did not prevent the uredospores of Fuccima

coronata from germinating. -, , i, ■ t ,^a .nno«

Action on Insects.— Mouillef art treated phylloxera-infected vines
with a dilute solution of KCNS. An infected pot plant was watered
with the dose recognized as capable of killing the vine, say 0-5 gramme,
dissolved in 250 cubic centimetres of water. Whilst the vine was
poisoned the phylloxera were uninjured. Sulphocyanide very ener-
getic on plants, is thus with the same dose without action on ttie
phylloxera and cannot thus be used against it.

Addendum to Chapter VII., p. 129— being omission from Section
55, Potassium Sulphocarbonate : — . ,, i <■

Tipula Oleracea (meadow tipula).-To destroy the larvae of
tipula, carbon disulphide may be replaced by spraymg meadows and
fields with a dilute solution of potassium sulphocarbonate. J^arthon,
who recommends this treatment, advises to test previously Jhe dose
which will not injure the plants on which it is ^ be app led. A
solution of 0-1 to 0-5 per cent never injures plants and kills all under-
,ground larvte.

CHAPTER VIII.

BAEIUM CHLOEIDE — BARIUM SULPHATE — BARIUM CARBONATE-
BARIUM SULPHOCARBONATE -CALCIUM OXIDE (QUICKLIME)— CAL-
CIUM SULPHIDE— CALCIUM CHLORIDE— CALCIUM CHLORO-HYPO-
CHLORITE (BLEACHING POWDER)— CALCIUM SULPHATE (GYPSUM
PLASTER OF PARIS)— CALCIUM SULPHITE— CALCIUM CARBIDE-
CALCIUM PHOSPHIDE— CALCIUM ARSENITE.

39. Barium Chloride, BaCl,. — Preparation. — By treating
barium carbonate (Witherite) with dilute hydrochloric acid. Carbonic
acid is given off and barium chloride crystallized as small rhomboidal
lamella formed with two molecules of water of crystallization.

Properties. — Barium chloride is soluble in water ; 10 gallons of
water dissolve 45 lb. at 15° C. Its taste is sharp. It is so poisonous,
that 4-5 grammes, say 60-75 grains, according to Parkes, kill a man, on
whom it first induces general weakness, then paralysis.

Action of Barium Chloride on Plants.— When plants are watered
with barium chloride in 0'05-0'5 per cent solution, chlorosis is in-
duced and lesions occur on the roots. This action is more pronounced
the younger the plant, and likewise varies with the nature of the
plant. Barium chloride behaves like common salt and like carbonate
of hme.

Action on Insects. — It appears to be very poisonous to insects.
Absorbed with food this salt kills them as rapidly as arsenical pre-
parations.

Use against Plant Diseases. — Maravek recommends 2 per cent
solutions to kill injurious insects. G. Staes uses it with success against
the ravagers of young beets, and especially against the altises which
sometimes completely devour the young leaves. Young plants support
a few days after sprouting a 2 per cent solution of BaCl.,, and when in
leaf a 3 per cent solution. Three sprayings kill coleopterous parasites.
Mokezecki recommends spraying with BaCl^ to destroy the grub of the
following ravagers : Anisopterix cescidaria, Schiff. ; Hibernia margin-
aria, Bk. ; H. defoilarla, Cheimatohia hriimata, L. ; Urojnis iilvil,
Himera pennarla, Plilacetonodes sticticalis, and Ilyponomeuta malinella,
Zell. They recommend the use of this salt according to circumstances
in 1.] to 2-3 per cent solution, adding 12 per cent of sodium carbon-
ate to give adherence to the liquor by the resulting barium carbonate..
The action of this product on the grubs makes itself felt after four
hours, whilst emerald green under similar conditions requires twenty-
four hours to act. This poison, very violent to grubs and insects, would
appear to be harmless to the plants treated, for neither the leaves nor
the fruit appear to suffer in contact. It is, however, costly and very

am

CALCIUM OXIDE (QUICKLIME). 139

poisonous ; it must, therefore, be used with great caution, especially on
meadows u^ed as pasture for domestic animals.

Weevils. — Still recommends Bad, to kill them.

Peritelics griseus (vine weevil). — Stromer remarks its presence on
the hop, and recommends spraying with BaCl., solutions to kill it.

Phorodon humili, Schrank (hop aphis green-fly). — Metzger kills this
louse by spraying with 1 per cent solutions of BaCl.^. The results ob-
tained have been very satisfactory, and he regards this salt as more
efiiaacious than Dufour's insecticide, and extracts of quassia. As
aqueous solutions of Bad, want adhesiveness, Metzger recommends-
a paste of 2 per cent of barium chloride and 1"5 per cent of soft soap.
Eight days after treatment the aphides had entirely disappeared.

Rodents. — Barium chloride acts on rodents like carbonate of
baryta. To exterminate them radically Hilner places bread dipped
in barium chloride in their runs.

40. Barium Sulphate, BaSO^. — -Passerini found that pastes made
with barium sulphate had no action on Peronospora viticola, De By.

41. Barium Carbonate, BaCOy. — Preparation. — By precipitat-
ing solutions of barium chloride by carbonate of soda. The natural
carbonate (Witherite) is not used as such.

Properties. — Poisonous, insoluble in water.

Use. — Largely as poison for the rodents which ravage cultivated
land. One pound of bread is mixed with f oz. of sugar and ^ lb. of
precipitated carbonate of baryta ; the mass is kneaded and then divided
into about 2000 pills (Eessler). One lb. of barley meal is kneaded
with ^ lb. carbonate of baryta and the amount of water necessary to
make a stiff paste and divided into pills and laid in their runs
(Crampe).

42. Barium Sulphocarbonate, BaCS^. — Preparation. — By
treating a concentrated solution of barium monosulphide by carbon
disulphide, solid barium sulphocarbonate is deposited.

Properties. — Barium sulphocarbonate is a yellow salt slightly
soluble in water and resists the action of the carbonic acid of the air
for some time ; it is more stable than alkaline sulphocarbonates, but it
is equally poisonous to plants, and has equal powers as an insecticide.

Use. — Phylloxera vastatrix, Planch, (phylloxera of the vine). —
Mouillefert examined its effect compared with alkaline sulphocarbonates.
Two vines were stripped down to the large roots and treated with 75
grammes (24- oz.) of barium sulphocarbonate ; the first was not watered
in any way, whilst the second was immediately watered with 6-5 litres-
of water, say 1\ gallons. With the latter the result was perfect, whilst
on the roots of the first a large number of undestroyed parasites were
found. Barium sulphocarbonate exists a long time in the soil without
decomposition, and if not dissolved by heavy rain its action is toO'
slow, and is not transmitted to the deep roots. The latter are not
therefore surrounded by a sufficiently poisonous atmosphere to kill the
phylloxera and the results are bad.

43. Calcium Oxide (Quicklime), CaO. — Occurrence.— Widely
in nature ; chiefly as carbonate, sulphate, silicate, and phosphate of
lime.

140 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Preparation. — Quicklime may be made from carbonate of lime,
either in the pure state as marble or chalk, or impure as marl or lime-
stone. Limestone is burnt in lime kilns by heating it gradually to a
Ted heat. This heat, kept up for three days on an average, decom-
poses the limestone into quicklime and carbonic acid.

CaCO, = CaO + CO..

As soon as the burning is finished and the mass cooled, it is packed
in casks, and hermetically sealed so that the air does not affect it by
its carbonic acid and moisture.

Properties. — Lime is converted by the action of water into hydrate
■of lime (CaOH^) or slaked lime. In slaking, the lime gives off much
heat and swells or increases in bulk. In contact with carbonic acid
•calcium hydrate is converted into calcium carbonate (CaCOg). Milk
of lime exposed to the air does not keep more than two to three
months, and gradually loses its caustic properties. Lime is very
slightly soluble in water, which only dissolves at the ordinary tempera-
ture 0-14 percent; hot water only dissolves O'l percent. Lime stirred
up with water remains suspended, and forms a milky liquid, " milk of
lime ". This milk is the fatter the more pure the lime from which it
is made. There are two sorts of lime, fat lime and thin lime. The
first comes from the burning of almost pure limestone, such as chalk
or marble ; it is white, and gives off much heat on slaking and increases
two to three times in bulk ; it forms with water a fatty and binding
paste. Thin lime, on the other hand, is produced by the impure lime-
stones referred to above ; it is grey, and disengages little heat on slaking ;
mixed with water it hardly swells and forms a short paste. For
agricultural purposes, and particularly for agricultural medicine, it is
necessary to choose a fat lime, which yields on slaking a very caustic
impalpable powder, which, stirred up with water, yields a milk with
great adherence. To increase this still more, a little cement, bullocks'
blood, potters' clay, or cow dung is added. The white colour, often too
glaring, is subdued by stirring in a little lampblack into the milk of
lime.

Use of Lime as Manure. — Lime is necessary to plants. Crystals
of oxalate and carbonate of lime exist in the cell-walis to which they
impart rigidity. In its absence farm crops languish, young plants
stop growing, the roots die. Liming the soil has for a long time been
largely applied, for lime spread on the soil, especially on heavy ground,
produces heavier crops of potatoes, peas, beans, tares, clover, lucerne,
etc. Moreover, lime destroys the noxious weeds, which require a soil
poor in or almost deprived of lime and sometimes even acid. The
role played by lime in the practice of farming may be explained thus :
When lime is ajjplied to the laud it neutralizes the acidity of the soil,
chiefly humic acid, which it converts into huniate of lime ; the fer-
ments in the soil which do not work in acid lands then develop in the
slightly alkaline medium created by the lime ; the organic matter is
disintegrated and decomposed ; its nitrogen is converted first into
ammonia and then into nitric acid, the presence of which is necessary
to the nutrition of cultivated plants. Lime by rendering the nitrogen

CALCirM OXIDE (QUICKLIME), 141

contained in humus assimilable by plants thus modifies the flora and!
the yield of cultivated land ; plants of poor nutritive value, such as
mosses, heather, reeds, and rushes, disappear, whilst delicate meadow-
plants — leguminosae and gramineae — -are greatly developed. A peaty
soil after liming is rapidly converted into arable land. But if liming
is a very desirable operation it is ver}^ exhaustive to the soil. The or-
ganic matter which forms a nitrogenous reserve for the plant rapidly
disappears under its action. Fresh reserves must therefore be brought
on to the land, as farmyard dung, if regular and satisfactory yields are-
to be obtained. Soils deficient in lime are generally poor in phosphoric
acid ; thus liming should be accompanied by phosphatic manures, for the
effect of lime would not be perfect if any element necessary to the plant
was deficient in the soil. Besides lime not only decomposes the humus,
it transforms certain minerals rich in fertilizing elements ; the clays-
which contain potash, for example, are converted into double silicates,
of alumina and lime and soluble potash. At the same time the lime
acts on the neutral sulphates in chemical manures, fixing the sulphuric
acid and bringing the nutritive elements into a more assimilable form,
such as sulphate of iron, sulphate of potash, sulphate of ammonia.-
Lime greath^ modifies the soil with which it is incorpoi^ated, it gives-
strength to light land because the humate of lime agglutinates the-
earthy particles together ; strong soils are rendered more friable and
wet soils sufficiently dry. Yet ail the benefits of liming disappear if
used iu too great amount. Yiala found by trials on the vine that lime
in excess produced symptoms of chlorosis whilst small amounts ap-
plied gradually yield a luxurious vegetation.

Muntz and Girard find it more preferable to apply lime in small
doses every three j'ears than to apply large quantities at longer intervals.
The amount of lime to apph- varies with the composition of the soil
and its depth. Liming should always be done in autumn. A soil'
to be fertile should contain a minimum of 3 per cent of carbonate of
lime and even 5 per cent in clay soils. On granite soils it is necessary to-
apply 10-12 hectolitres of lime per hectare (11-13"2 bushels per acre),
whilst on soils rich in organic matter 20-2'± hectolitres {22-26'4 bushels-
per acre) must be applied. Friable soils only require 15 hectolitres (16;^
bushels per acre), heavy soils 20-30 hectolitres (11-33 bushels per
acre), and peaty soils 35 hectolitres {S8^ bushels per acre). The
following is the method to pursue in liming land : The quicklime is
laid down directly on the fields in heaps of 20-50 litres (4'4-ll gallons)
and the heaps covered with a layer of soil. In three weeks the lime
is completely converted into hydrate. The lime is then spread uni-
formly over the ground and then harrowed into the soil so as to mix
it intimately therewith. This method is the simplest and quickest.
A manure rich in nitrogen and in lime is made by slaking lime in
composts where the lime is mixed with farmyard dung, organic matter,
farm waste, etc. Three weeks afterwards the whole is covered with
earth. If v,'atered frequently slaking is finished in a few months, and
the lime so obtained may be spread on the land and mixed with the
soil.

Action on Plants. — Milk of lime is a strongly alkaline product

142 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

which behaves to plants like alkaline liquids, that is to say, it injures
the young buds but is without action on the adult organs. Cellulose
is not attacked by lime, so milk of lime may be used with impunity
in spraying on the different parts of adult plants, and the strength of
this milk of lime may be increased at will. There are, however, some
exceptions. Sorrel, for example, does not stand its action ; the same
applies to mosses and lichens, the growth of which requires much
moisture, are quickly destroyed by lime and especially by quick-
lime.

Use against Fungi. — Alkaline substances have a decided but
weak action on fungi spores. This property was utilized in the be-
ginning of last century to destroy the spores of smut and bunt ; at that
time no substance fit to render the same service was yet known, and
lime was officially recommended by the (French) Government although
it had not given very complete results. The chief advantage was
that the method did not injure the seed. However, Phillipar found
that after this process had been applied, and although all the grains
were uniformly covered with lime, the resultant crops still gave 260
bad ears x^er 1000. Girardin likewise found 112 bad ears per 1000
after macerating the seeds for twenty-four hours in 1 per cent milk
of lime. Loverdo believes that this bad result is due to the cellulose
nature of the exospore of the Ustilaginea which opposes a resistance
to the alkaline action of lime. According to tests by Kuhn the spores
of the bunt of wheat, Tilletia Caries, resist milk of lime for five hours,
but after twelve hours' immersion they have lost their vitality. Bolley
does not believe in lime as a disinfectant. Slaked lime in powder had
no appreciable action, but immersion for twenty-four hours in a milk
of lime gave a result especially on addition of a certain amount of
common salt. The following, according to Mathieu de Dombasle,
is the comparative result of this treatment, bad ears in 1000 carried
out in various ways : Blank wheat, 486. Wheat covered with lime
powder, 476. Wheat moistened with milk of lime, 260. Wheat
immersed for twenty-four hours in milk of lime, 21. Wheat im-
mersed for twenty-four hours in milk of lime of 2*5 per cent strength
and 4 per cent common salt, 2. The effect of lime is thus very
perceptible, but as soon as common salt or sulphate of soda is added
the effects are much more perfect. Lime is not now used alone to
disinfect cereal grains, but is an indispensable aid to this treatment.
Its chief role is to neutralize the disastrous effects of the poisonous
salts on the germinative capacity of the seed and to fix the anticrypto-
gamic products in an insoluble form on the surface of the seeds. By
treating with milk of lime seeds which have been steeped in a solution
of blue vitriol, the action of which is very injurious to the vitality of
the seeds, this salt is converted into copper hydrate. The latter mixed
with sulphate of lime forms round the grains a deposit of preservative
matter, so little soluble as not to be washed away by the water in the
soil and capable of preventing the germination of the spores adherent
to the surface of the grain as well as the invasion of filaments of bunt
which might be present in the soil. In America attempts have
been made to disinfect seed corn by a mixture of milk of lime and a

CALCIUM OXIDE (QUICKLIME). 143

5 per cent solution of soap. But the results were unsatisfactory.
The spores of PliytopJithora infestans, De By. (potato disease) resist milk
of lime ; the latter is incapable of arresting the development of that
disease. Rust of wheat likewise resists the action of lime even in
heavy doses and in mixing it with equal parts of sulphur.

Hitchcock and Carleton have, however, found that lime paralysed
the growth of the uredospores of Puccinia Bubigo vera, Wint. (rust of
wheat). But lime has no effect on Hypomyces jMrniciosiis, Magnus,
mole disease of the mushroom. Used to combat the Gicig^iardia
Bidwellii, Viala et Ravaz (black rot of the vine), lime gives fairly good
results. Galloway obtained by this method an appreciable diminution
of bad seed : on the untreated plot 45 per cent of diseased seed, on
the limed plot only 20 per cent of damaged grain. Debray also re-
gards the liming of the vine as a cure for Gleospormm ampelophagum,
Sacc. (grape rot), Botrytis cinerea, Pers. (the noble or grey rot of the
vine). Sorauer advises to spread quicklime on the grapes in autumn
as soon as this mould appears.

Qummosis of Stone Fruit Trees. — Sorauer advises to lime the
ground strongly around the trees attacked by this disease so as to
render the soil drier and warmer, an essential condition in counteract-
ing this disease. Wiesner regards this diseased condition of the trees
as due to the development of a special ferment, a species of diastase.
Be that as it may, a good result is obtained by spreading lime in the
autumn at the foot of the trees. If the trees in a moist soil suffer from
canker or rot of the roots, the roots must be stripped, lime spread
between them and the soil drained. This treatment leads to a per-
ceptible improvement in the diseased condition of the tree.

Bhizoctinia violacea, Tul. (rhyzoctinia of the beet). — Frankel re-
commends to spread slaked lime in powder on the fields to diminish
the number of parasites. Here again lime only acts directly as on
mushrooms by changing the conditions favourable to their develop-
ment ; it arrests their growth and imparts to the plant by converting
the humus into assimilable matter the capacity to resist disease better.
Unfortunately it is alleged that lime, whilst it diminishes the amount
of these parasites, favours the development of other and not less
formidable beet diseases, e.g. Phoma tabifica, Prill, and Dela. (disease
of the petioles of beet leaves). The alkalinity of the medium in a wet
soil exerts a generally favourable influence on the development of the
bacterian diseases of plants. Wheeler, Tower, Tucker, and Sorauer
regard lime as favouring potato scab considerably. To reduce these
diseases it is on the contrary useful to render the medium acid, say by
green vitriol or by " sulpharine," which contains 15 per £ent sulphuric
acid.

Ophiobolus graminis, Sacc. {Pietin), (diseaseof wheat stalk). — Sance
advises as a cure to sow by hand 176 lb. of quicklime per acre as
soon as the disease appears. Marenghi recommends quicklime as a
preventive ; he advises to spread 3-4 cwt. per acre and to harrow the
ground slighth' afterwards.

Tobacco Leaf Spot. — Van Os to prevent this disease ploughs
in 11 bushels of quicklime per acre. He thus brought down the

144 INSECTICIDES, FUNGICIDES, AND WEED KILLEES,

diseased plants to 7 per cent, whereas it was 100 per cent in the-
unlimed plot.

Plasmodiophora Brassicce, Woronine (finger and toe). — Lime is-
an excellent means of preventing the spread of this fungus. Nijpels
advises to mix the infected soil with half a litre of lime per square
metre. Seltensperger applies the following treatment: During and
after transplanting there is deposited at the foot of each cabbage in a
sort of deep cup, of 6-10 centimetres, made for the purpose, a big
handful of quicklime which is covered with earth to the level of the
surface. Of 600 cabbages and cauliflowers treated thus none were
attacked by the disease, whilst the untreated plot was seriously
compromised ; 25 per cent of the cauliflowers and 50 per cent of the
cabbages were attacked. Halstead who advises this treatment in
America believes that it has a preferable effect on plants to that of
bouillie bordelaise, corrosive sublimate, blue vitriol, kainite, but it is
necessary to use at least 2 tons 8 cwt. per acre.

Use of Lime against Nematodes. — Lime in strong doses is a
cure for these worms. Lime spread on the surface of the soil changes
its characters entirely. The humus (mould) sought after by these
worms being transformed the soil does not any longer present the
conditions essential to their growth. The evolution of the nematodes
is, moreover, arrested by the alkalinity of the soil. Although lime,
and especially quicklime, may disinfect the soil and thus improve
certain crops it cannot replace carbon disulphide, which according to-
Girard destroys more surely all the nematodes in a field.

Heterodera Sdiachtii, A. Schmidt (nematode of the beet). — Holl-
rung found this nematode very sensitive to the action of lime, and that
by mixing 1 part of quicklime with 4-6 parts of soil these nematodes
were destroyed. Kuhn advises to apply the lime in autumn, as in
that way whilst diminishing the number of nematodes the lime trans-
forms the humus into assimilable matters and enables the more vigor-
ous beet to reconstitute its radicular system attacked by the parasite.

Tylenchus devastatrix, Kuhn. — The liming of seed-corn is without
effect against these, and disinfection does not diminish this disease as
the insects are polyphagous and even saprophytic. These insects live
on the most diverse plants, causing very different diseases, chiefly on
onions, clover, potatoes, poppies, etc. Weiss advises to burn the stems-
after harvest and dust the fields with quicklime and apply mineral
manure in abundance in the springtime.

Use against insects. — Few insects are sensitive to the alkaline
action of lime, yet those with soft skins and delicate larvae do no
resist milk of lime or powdered quicklime, which they particulaily
dread. Lime thus forms an excellent medium for fighting these
parasites. But in most cases lime has only a mechanical action on
the spot occupied by the insect.

Perroncito's experiments on the eggs of Bomhyx Mori, L., have
proved that milk of lime cannot kill the latter, for the eggs of this
bombyx are capable of being perfectly hatched after steeping in
milk of lime for twenty-four hours. In spite of this harmlessness milk
of lime is used in arboriculture, for the liming of the trunks is an ex-

CALCIUM OXIDE (QUICKLIME). 145

cellent method of diminishing the number of these parasites. The
previous cleaning of the trunks removes all moss, lichens, and bark
which formed so many refuges in which the insects and their larvae
pass the winter and lay their eggs. It plays as great a role as the
liming itself. All the hiding-places preferred by these parasites are
destroyed, and not knowing where to deposit their progeny they are
obliged to seek refuge elsewhere. x-\.gainst cochineals lime exerts a
special mechanical action ; their shell, covered by a thick layer of lime,
is, owing to the contraction of the lime, detached from the branch on
which it was fixed, thus causing its death.

Liming of Trees. — This practice advised by Blanchere is a very
good one for it frees the trees well from parasites. The strength of
the milk of lime may be increased to a thick paste without injuring
the tree. To secure good disinfection it is better not to use milk of
lime alone but mixed with tar and naphthalene as advised by Balbiani.
To complete the work of liming it is well to collect and burn all the
broken particles of bark and to bury with quicklime all the fallen fruit.
As it slakes the lime destroys the parasites by the heat given off. By
this means the number of anthonomes, cheimatobias, and even
schizoneura lanigera (woolh' aphis) are greatly diminished. The re-
sults will be more complete the more regularly the liming is repeated.

Scolytides. — The Bostrichi and the Hylesini, injurious to conifei'S,
the scolytides, injurious to deciduous forest trees, cannot be destroyed
by liming the trunk, but regular whitewashing with lime may remove
them. Again whitewashing with thick and pliant lime in autumn
after scraping the tree stops the exit orifice of the scolytides and renders
-the bark less accessible to the female in winter. Eobert advises summer
liming. If during summer a tree is badly infested by these insects
there must be no hesitation in making longitudinal cuts or a surface
barking, taking care immediately afterwards to coat the wound or the
trunk with milk of lime. But when the tree is too far gone it is pre-
ferable to fell it and burn it, taking care to protect all the adjacent trees
by liming or with the coating described further on. This opera-
tion, extensively applied in Austria, consists in painting the trunks and
even the branches with a mortar made thus : Macerate 54^ lb. of tobacco
in 1-1 gallons of hot water kept at a rather high heat, add 11 lb. of ox
blood, and 11 lb. of Hme and cow dung to a pasty consistency. The
trunks and branches are coated several times with this composition
until a hard weather-resisting coat is formed.

Amongst the better-known scolytides there may be quoted
Eccoptogaster Pruni, Eatz. (scolytus of the plum). E. regidosus, Koch,
(rugose scolytus). E. Scolytus, Eatz. (elm scolytus). Hijlesinus oUjyerda
(hylesinus of the olive-tree, cirai, taragnon). Tomicus Ficus, Er. (bostrich
of the fig). Tomicus Mori, Aub. (bostrich of the mulberry). Bostrichus
dispar (apple bark beetle), Hllw., and B. saxesini, Eatz., both injurious
to fruit trees. All these scolytides may be removed by the above
treatment.

Colas2)idema atrum, 01. (negril).— Debray recommends liming of
lucerne the moment the young larvae commence their inevitable invasion,
but so as not to be forced to lime all the field of lucerne it is well to

10

146 INSECTICIDES, FUXCtICIDES, AND WEED KILLEES.

mow it prematurely and only leave a small strip of lucerne where all
the larvae will take refuge ; this strip is then limed.

Anthonomus Piri, Boh. (anthonome of the pear) ; A. Pomorum
(apple blossom weevil). — Poubelle limes the trees in autumn with a
mixture of lime 22-33 lb., flowers of sulphur 22 lb., gelatine 6-6 lb,, the
whole mixed with water to a thick paste whiijh is spread on the trunks
after removing the moss.

Haltica Ampdophaga, Geur. (altise of the vine). — The green altise
which ravages the leaves of the vine may be destroyed by projecting
powdered lime on to the vines (Audibert).

Crioceris Asparagi, L. (asparagus beetle). — Vial advises to dust
the asparagus with impalpable slaked lime preferably in the morning
dew.

Melolontha vulgaris, L. — Webster tried to destroy the larvae of the
cockchafer in fields by utilizing the heat given off by lime in slaking.
Trials made in a field infected with white-worm did not give good
results. Eitzema Bos also tried, but without success, to destroy insects
injurious to forests, e.g. Lophyrus Pini, L. smiilis, Trachea pinij^erda,
Gastropacha Pini, by spreading on the soil of the forests a large
amount of quicklime.

Agriotes Lineatus, L. — If lime is not directly injurious to the
larvae of this insect spread on the fields, it helps greatly to diminish
their numbers. According to Schilling annual liming yields still more
complete results. This improvement is due to the transformation
effected by the lime on the soil, which after having been wet and
charged with humus favourable to the evolution of the larvae becomes
drier after liming and unfit for their development.

Gryllotalpa vulgaris (mole cricket). — In Italy this orthoptera is
removed by liming at the rate of 16 cwt. to the acre.

The larvae of some Hymenoptera are very sensitive to lime.

Nematus ventricosus, Kl., N. Bibis, Scop, (the gooseberry and
current saw-fly). — Lime in itself forms a good means of destroying
their larvae. Firor, however, prefers a mixture of 4-4 lb. of lime and
2 '2 lb. of powdered tobacco which he spreads on the shrub after
moistening it.

Selaiidria {Eriocamjm) adumhrata, Kl. (slimy caterpillar, slimy
larvae of pear saw-fly). — Lime forms an excellent means of destroying
this sticky larva which skeletonizes the leaves of the pear.

Amongst the Lepidoptera a few may also be combated by lime.
The large white garden butterflies are destroyed by dusting freshly
slaked lime on plants and then watering them (Vial).

Cheimatobia brumata, L. (the winter moth, Evesham moth), Sesia
■myopiformis, Bkl. (sesia of the pear), Grap)holita Weberiana, W. V. —
'The liming of the trunks prevents the females of these butterflies from
-depositing their eggs. The caterpillars of the last two butterflies may
be destroyed l)y plastering the trees with a thick milk of lime mixed
with clay (Taschenberg) and applied at the time the caterpillar is mak-
ing its ravages.

Tingis piri. — This Hemiptera has been successfully combated
by lime, which ought to be applied as a whitewash in February.

CALCIUM OXIDE (QUICKLIME). 147

The Homoptera have Hkewise been fought by lime with more or
less success, for here again it is still by its desiccating properties
that it especially acts. By using milk of lime as thick and hot as
possible the contraction of the lime detaches the cochineals and kills
them at the same time. But a good result is not obtained unless care
is taken to prune the tree and clean it from top to bottom. Thus
cleansed and covered with a layer of lime the tree is not attacked by
cochineals, and the fumagine (fruit tree smut) which only lives on
the dejections of these insects is avoided. Liming is thus an in-
dispensable operation in arboriculture and it gives good results if
renewed each year.

Coccus Vitis, L. (red cochineal of the vine, vine scab). — Winter is the
best time to attack cochineals, for that is the time that these insects
get on to the trunks to lay their eggs. Bellot des Minieres advises
after pruning to clean the trunk completely, including scraping and
careful barking. It is then whitewashed with lime which protects it
against these insects.

Aspidiotus p)^'^"^^'^<^iosus, Comstock (San Jose louse). — To combat
this cochineal the Americans replace lime by a mixture of salt, sulphur,
and lime, sold as " salt lime and sulphur wash ". Applied in winter
on the trunks of trees this mixture forms a hard crust which prevents
the reproduction of this insect.

Schizoneura lanigera, Hausmann (woolly aphis). — Muller advises
to coat the ulcerated spots infested by this aphis with milk of lime
after having completely cleaned them. To destroy the woolly aphis,
which live underground around the stock and the roots, Goethe
advises to strip the trees in autumn or winter to a depth of 2 feet, and
water them copiously with milk of lime. A layer is then made 3
centimetres, say 1'2 inches, thick of quicklime, then the earth is covered
in. Taschenberg finds this method very efficacious. To combat green
lice, Arbrinjer advises to lime the whole tree in winter or spring. If
an insecticide be added to the lime, such as tar or naphthalene, success
is complete, for in that case the eggs of the louse are killed at the same
time as those of the most diverse insects. Balbiani's mixture as well
as milk of lime are incapable of preventing the opening of the buds,
which are thus protected against insect attacks.

Limaces (snails) are also killed by lime. Tf it is a case of destroy-
ing snails on plants, freshly slaked lime is blown on to them from a
bellows. Each snail touched dies forthwith. The best time for this
operation is early in the morning, or in the evening a little after fall
of day. In vineyards, the buds are protected against small snails by
spreading slaked lime in powder on the stock, and laying a train of
lime, 7-8 inches, around each stock. In the fields, lime is sown by
hand at the rate of 25-30 bushels of slaked lime per acre. In des-
troying snails lime spread as an impalpable powder gives the best
results. The operation is repeated several times if it is desired to
reach all the snails. Lime used against snails tends to be replaced by
nitrate of soda, tobacco powder, but especially by a 3-4 per cent solu-
tion of blue vitriol. This solution is sprayed on the plants at the time
the snails are on their rounds ; the snails which are attacked die

148 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

immediately and those which pass on to a branch covered with blue
vitriol are likewise poisoned.

Use against Mammals. — According to Taschenberg, plants are
preserved from rabbits, hares, deer, by coating with lime. It is prefer-
able to add strong smelling substances, such as petroleum, aloes, lard
(rubbing a skin of lard against the trunks of 100 trees suffices). To
impart more adherence and thickness to this paste, it is well to add
cow dung and thin it down with purin. Seed can be protected against
mice by coating them with a thick milk of lime and spreading
petroleum thereon. They are then sown immediately after this treat-
ment. Such seed are not attacked by rodents.

Late Frosts. — Lime is successfully used against late frosts. When
frost is to be feared, slaked lime in powder is spread on the buds of
vines and fruit trees from a bellows so as to cover all their surface.
These buds well covered w-ith lime will not be attacked by the frost
nor burnt by the sun striking them afterwards. With fruit trees it
is necessary to operate before the blossoming of the flowers, or after
fructification has taken place.

44. Calcium Monosulphide. — Preparation. — (1) By heating
lime in a current of sulphuretted hydrogen ; (2) by heating a mixture
of sulphate of lime and charcoal ; (3) by boiling milk of lime with
sulphur ; the polysulphides are so prepared, but by using larger propor-
tions of sulphur. The product obtained by boiling milk of lime with
excess of sulphur is called calcareous liver of sulphur. The paste
bouillies employed to combat plant diseases are of very diverse com-
positions, and contain either a basic monosulphide or a monosulphide
or polysulphides of calcium. They are generally prepared by boiling
a milk of lime with flowers of sulphur, until the latter is completely
dissolved. After cooling there are incorporated as occasion requires
very diverse substances, such as glycerine, soft soap, copper salts,
naphthalene, etc. To prepare and preserve these pastes, enamelled
vessels are used. The bouillie recommended by Mohr is the one most in
use. It is made thus : 22 lb. of quicklime are slaked, then made into
a milk of lime and run through a sieve; on the other hand, 11 lb. of
flowers of sulphur are stirred into 2-2 gallons of crude glycerine; the
two liquors are mixed and the bulk made up to 22 gallons of liquid
which is boiled for one hour over a small fire. A concentrated solution
is thus obtained marking 18°-20° B., which is appropriately diluted when
required for use, to suit it for particular purposes, with 10-12 parts of
water. It is best to dilute it with a milk of lime of 0'5 per cent
strength. Crouzel's anticryptogamic is prepared thus : 14 oz. of lime
are slaked and the milk of lime therefrom run through a sieve, 35 oz.
of sulphur added and the whole completed with water so as to produce
loO oz. of bouillie. When a homogeneous mixture is obtained, it is
brought to the boil for an hour, care being taken to replace the water
evaporated. The solution is filtered or decanted ; it marks 20° B., 0-1
oz. of naphthalene is added and 2 oz. of hyposulphite of soda, and the
whole completed with water to 100 gallons. This preparation is used
as it is against the cryptogamic diseases of the vine.

Properties. — Calcium sulphides are soluble in water, and in all

CALCIUM SULPHIDE. 149

proportions. Moistened with water and in contact with air they are
rapidly converted into carbonate of lime and sulphuretted hydrogen.

CaS, + COo + H.O = CaCOy + H.S + S.

But simultaneously with this decomposition they undergo partial
oxidation into hj'posulphite of lime. Calcium sulphides are neutral.
They act by the amount of sulphur which they contain. To prevent their
too rapid decomposition in moist air, various substances have been incor-
porated, such as glycerine and milk of lime, in the proportions given
by Mohr (p. 148), molasses, soft soap, in the proportion of 1-2 per cent.
These substances also cause the bouillies to adhere better to plants.

Action on Plants. — Calcium sulphides are less injurious to the
green parts of plants than potassium sulphides, because their solutions
are not caustic. Solutions of glycerinated monosulphide may dry on
the leaves without injuring them. But in spite of that it is necessary
to avoid the too rapid decomposition of these sulphides for the
sulphuretted hydrogen produced is very injurious to the plant; 0'75
per cent of this gas diffused through the air may poison certain plants.
The use of glycerine to form bouillies, and of water and lime to dilute
them prior to use, helps greatly to attenuate the effect of this gas ; by
delaying the decomposition of the sulphides, too large an amount of
sulphuretted hydrogen is prevented from being formed at one time.
The damage caused by different plants, as well as on the roots
treated, are likewise caused by hyposulphite of lime often present in
impure calcium sulphides ; hyposulphites scorch the leaves especially
during strong summer heat. Owing to their reducing action sulphides,
and particularly calcium sulphides, are injurious to the roots which
come in direct contact with it. The experiments of Fithbogen,
Schiller, and Forster have proved this effect.

Action on Fungi. — The action of calcium sulphide on the
mycelium of fungi is in principle the same as that of sulphur, but
polysulphides, which are in a way solutions of sulphur, may be looked
upon as more active than sulphur, even used in its most impalpable
form. Whilst sulphur has no radical action on the Erysiphece, the
mycelium of which is exposed without any protection on the surface
of plants, calcium sulphides act on fungi which live in the plant itself.

Action on Insects. — Generally insects are not disturbed by solu-
tions of calcium sulphide. It is otherwise with acari, plant lice, which
are easily destroyed by this preparation. Sulphides are, so to speak,
specifics against the Phytoptides which produce the different erinoses
of plants and the most diverse galls. Used against these lice their
action, otherwise very imperfect, is solely due to the sulphuretted
hydrogen given off, which is exceedingly poisonous to these insects.

Use against Fungi. — Calcium sulphides form an efficacious and
economic means for the destruction of the most various parasites. They
are practical substitutes for sulphur. They have in themselves a re-
markable action ; but it is well to incorporate in their solutions sub-
stances capable of protecting them against moist air which renders
them inactive too soon and causes them to poison plants. Mohr
advises their use against cryptogamic diseases.

150 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Cuscuta (dodder). — Carrigon employs calcium sulphide with suc-
cess to destroy dodder in forty-eight hours. To obtain this effect
calcium sulphide is spread on the ravaged parts of the field, and these
spots sprayed shghtly with water. The result is especially favour-
able in wet weather. If this treatment is applied before the maturity
of the grain the dodder may be considered as eliminated from the
fields.

Peronospora viticola, De By. (mildew of the vine). — Vesque re-
commends polysulphides against this parasite of the vine. A bouillie
is prepared for the purpose with 1 lb. of quicklime to 3 lb. of sulphur
in 10 gallons of water. The leaves and the grapes are sprayed at the
time the vine is usually sulphured.

ErysiphecB (mildews). — All these fungi can be destroyed by calcium
sulphides ; they act on their mycelium disorganizing them rapidly like
sulphur. Their use is, however, more simple, their action more
regular, because it does not depend on the temperature which, as
regards sulphur, is one of the conditions of success. Besides, solutions
being spread more uniformly on the organs of the plant attacked
the action is more thorough.

Uncinula Aviericana, How. (oidium of the vine). — Crouzel re-
commends his " anticryptogamic " against the oidium, the composition
of which has already been given. Spraying ought to alternate at
five or six days' interval with cupric preparations. Polysulphides em-
ployed without naphthalene or hyposulphite produce the same effect,
and Mohr's preparation arrests the oidium in full evolution. In the
spring 4 per cent solutions of polysulphides are used, 5 per cent
solutions after flowering, and 6 per cent solutions at the end of summer.
The latter do not injure the leaves. In the same way as for the
oidium, mildew of the vine, the polysulphides of calcium have been
used to destroy the following ErysiphecB (mildews) : Splicerotheca
pannosa (mildew of the rose and the peach) ; Microsphara Grossularice,
Wall, (mildew of the gooseberry) ; Erysij)]ie commimis, Wall, (mildew
of hay and clover). Nijpels recommends to use against mildew of
the rose a sulphide prepared thus : boil 100 gallons milk of lime
made with 20 lb. of quicklime and 40 lb. of sulphur; after twenty
minutes' boiling the sulphur is dissolved and the whole cooled. A
teaspoonful of this solution per litre of water for spraying suffices,
which should be done two or three times during summer.

Capnodium (fumagine). — The fumagine (fruit tree smut) is destroyed
by 5 per cent sulphide solutions, but according to Franck and Kruger
this product cannot destroy the cochineals whicli produce it.

Amongst the black-blights thei-e are also some which may be com-
bated with polysulphides : Gloeosporiuvi ampelophagum, Sacc. (an-
thracnose of the vine). Against this disease it is necessary to apply a
spraying of sulphide before the flowering of the vine.

Clados])ormm fulviim, Cooke (tomato disease). — Mohr particularly
advises the use of polysulphides against this disease which act in a
more efficient manner than copper salts.

Actinonema Bosece, Fr. syn. (Asteroma radiosium, Fr.). — Mohr re-
commends two or three sprayings during summer.

CALCIUM SULPHIDE. 151

Hypomyces loerniciosus, Magnus (mole disease). — Constantin and
Dut'our found that this disease can be combated by calcium sulphides.

Xectria ditissime, Tul. (canker of the pear.-tree, canker of the apple-
tree, canker of the beech-tree) ; Nectria cinniharina, Eode. (necrosis
of wood). — Mohr advises to combat these two parasites with glycerin-
ated sulphides. The wound is deeply incised, cleaned, and then coated
several times with a solution of glycerinated sulphide of calcium,
titrating 15°-2o° B. When the wound is dried up it is covered with a
linseed oil varnish (? boiled oil). To obtain a cure it is sometimes
well to repeat this treatment several times a year. It is also recom-
mended to use a concentrated solution of sulphide mixed with a thick
milk of lime and to coat the wound after drying with a mastic of some
sort.

Fusicladium Pirinum. Fuckel (pear scab); Fusicladium dentriticum
(apple scab). — Mohr advises the use of glyceriuated sulphide of lime,
of the usual strength, as soon as the fruits have formed and are the
size of a pea, two or three additional sprayings being given during
the summer.

Hydnes and Polypores are combated with calcium sulphides :
Hydnuvi Schiedermayri, Heufl. ; Polyporus sulphureus, Fries; Poly-
porus igniarius, Fries (false tinder fungus). — Mohr advises to combat
this disease by excising all the diseased wood and to plaster the
wounds sevei'al times with glycerinated sulphide of lime of 20° B., then
to coat with mastic. Mohr also advises to combat certain rusts wnth
calcium sulphide thus : Phragmidmm subcorticum, Schrank (rose rust),
and also the rust of the pines and spruces, such as Cliryso^nyxa abietis,
Unger (rust of needles of Epicea), and others. The treatment should
be carried out in May so as to avoid fresh infection of the plant.
Peridermiiim p)ini, Walr. (vesicular rust of the bark of the pine) ^ ;
Peridermium ohlongisporiuvi, Fuckel (vesicular rust of pine needles). —
Mohr advises to combat these diseases with his bouillie diluted with
10-12 parts of water. The result it appears is as good as with bouillie
bordelaise.

Exoascus deformans, Fuckel (Cloque du Pecher), (blistering,
wrinkling, or curling up of the leaves of the peach). — Pierce and Mohr
advise spraying with calcium sulphide to prevent this disease ; accord-
ing to these authorities complete success is obtained if, as soon as it
makes its appearance on the first leaves, they are sprayed with a i per
cent solution.

Use against Insects. — Carpocapsa pjomonella, L. (codlin moth,
apple worm, pyralis of the apple). — Mohr advises calcium sulphide
glycerinated to ^j^ to prevent apples becoming wormy. To prevent the
hatching of the eggs laid by the female on the young fruit a first
spraying should be made as soon as the fruit is formed or soon after
flowering ; the fruit should be inspected from time to time and sprayed
afresh where required.

Phylloxera vastatrix, Planch, (phylloxera of the vine). — Mouillefert
tried to determine the action of calcium pentasulphide on this louse, by

^ Pine " cluster cups ". — Tk.

152 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

making injections round an infested stock, amounting in all to 350 cubic
centimetres, of a solution of 23° B. diluted with 7 litres of water [twenty
times its volume]. The result was perfect on the upper roots but not
complete on the deep roots.

Ajyhides (naked plant lice). — Many observers have recommended
2-4 per cent solutions of calcium monosulphide and even the same
product in the form of powder as a specific against green lice.

Aphis Per sices, Sulz, which is destroyed at the same time as the
leaf curl {Exoascus deformans) by a 4 per cent solution ; likewise the
Aphis Oxyacantha, Koch, which causes the cloque of the hawthorn ;
Aspidiotus 2:)erniciosus, Comstock (San Jose louse) ; Aspidiotus Aurantii,
Maskell (cochineal of the orange). The Canadian Government advises
for the destruction of these dangerous cochineals a bouillie consisting
of 18 lb. of slaked lime, 18 lb. of sulphur, and 5^ oz. of blue vitriol in
10 gallons of water. For the same purpose there is used in California
a bouillie composed of 6 lb. of slaked lime, 3 lb. of sulphur, and 2 lb. of
common salt (the latter added at the moment it is to be used) in 10
gallons of water. This bouillie, it appears also, kills the woolly aphis.
According to the researches of Coquillet these two bouillies even used
of double strength are not capable of entirely freeing the trees from
their parasites. They only destroy 50 per cent. Mohr likewise found
these bouillies incapable of replacing more active ones, and Franck and
Kruger regard this means as insufficient to combat the different species
of cochineal. Garrigou found that calcium sulphide spread in fine
powder on the young moving lice followed by spraying with water
very effectual. Calcium sulphide in powder is a specific for the de-
struction of acari against which it yields perfect results.

Tetranchus telarius (red spider, saw-fly). — Calcium sulphide may
prevent the premature fall of the leaves produced by the saw-fly ; it
also prevents the erinoses produced by the Taphrina, Fr., Erineum,
Pers., and PJiyllerium, Fr. ; it also destroys the Phytoptides which pro-
duce galls. As a preventive against these diseases spraying round
the plant and on the branches must be advised in winter after the fall
of the leaf and in spring before the opening of the buds. Coating the
tree with a strong bouillie so as to cover all the buds occupied by these
parasites is still more efficacious. The U.S.A. Minister of Agriculture
advises to destroy Eriophyes Bibis, Nal., syn. Phytoptus Bibis, Wester
(currant gall mite), and Eriophyes Vitis, Land., syn. Phytoptus Vitis,
Land, (erinosis of the vine), to use a bouillie consisting of 6 lb.
of lime and 6 lb. of sulphur in 100 gallons of water. To increase the
effect of the calcium sulphide 12^-25 lb. of soft soap may be added.
The milk of lime is boiled with the sulphur and the soft soap dissolved in
water added. Miss Ormerod (the late) and also Debray greatly recom-
mend calcium bisul])hite and found it superior to sulphur. Taschenberg
finds that a little alum renders its solutions more active.

45. Calcium Chloride, CaCL. — Preparation. — By treating marble
with hydrochloric acid. The crystals of CaCl.j6H.,0 thus obtamed are
heated to igneous fusion ; the mass is then cooled on a smooth surface
on which the chloride solidifies in white flakes with a crystalline
fracture.

CALCIUM CHLOEO-HYPOCHLOEITE (BLEACHING POWDEE). 153

Properties. — Fused calcium chloride has great affinity for water
(i.e. is highly deliquescent) ; in contact therewith it dissolves with
evolution of heat.

Use. — Comstock and Slingerland tried this product, comparatively
against other substances, to fight the lai-vae of Agriotes lineatus (wire-
worm), but did not obtain good results. Neither was Waite able to
destroy lichens by the use of a 1 per cent solution, whilst Jack recom-
mends it in strong doses to kill Eqidsetuvi palustre, or poisonous
horse-tail, in meadows.

46. Chloride of Lime (Bleaching Powder), CaCloO.^ — Prepara-
tion.— Commercial bleaching powder is a mixture of hypochlorite of
lime, calcium chloride, and lime. It is prepared by spreading slaked
lime in thin layers on trays laid in a masonry chamber, and passing
a current of chlorine over this moist lime, so that a certain amount of
unchanged lime remains at the end of the operation, which enables
the chloride of lime to keep longer, by protecting it against the car-
bonic acid in the air.

Properties. — Chloride of lime is a white powder with an acrid
taste, exhaling an odour of hypochlorous acid, HCIO ; it dissolves freely
in water, leaving a white residue of hydrate of lime. The weakest acids,
such as carbonic acid, decompose chloride of lime with disengagement
of hypochlorous acid ; chloride of lime must therefore be preserved out
of contact with air. The hypochlorous acid which is given off has a
very energetic action on organic matter, towards which it acts as an
oxidizing agent. This action is more rapid in presence of a mineral
acid.

Use. — Kolbe recommends chloride of lime to destroy poisonous
horse-tail {Equhetum palustre). In doses of 352 lb. per acre its de-
struction is complete. Chloride of lime has been used to destroy
insects. It has been tried against —

Ph)/Uoxera rastatrix, Planch, (phylloxera of the vine). — The
Departmental Commission of Herault which examined the processes
recommended to combat the phylloxera declared the two following
processes quite inefficient : Timbal's, which consisted in burying
round about the stocks 20 grammes (306 grains) of chloride of lime, and
Dupuis', which consisted in watering each stock with the emi de Javel
obtained by mixing 50 grammes of chloride of lime with 12-5 grammes
of carbonate of soda in 1 litre of water [in ratio of 5 lb. and 1^ lb. in
10 gallons of water].

Spilorjraplia Cerasi, F., syn. Tryjyeta Cerasi (cherry fly). —
Taschenberg recommends to prevent cherries from becoming wormy
to spread, after the fall of the cherries, around the tree a hot 1 per
cent solution of chloride of lime, which destroys the larvae buried in
the ground.

Formica (ants).— Taschenberg proposes for the destruction of ants
to spread on their nests a mixture of chloride of lime and of purin,
or to mix the earth of the nest with chloride of lime and to water im-
mediately afterwards with dilute hydrochloric acid. Cuboni believes
that in spraying fields with a milk of chloride of lime they are freed
from almost all parasites, and mice and moles are driven away. The

154 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

odour of this product would appear to be unpleasant to insects, and
the presence of chloride of lime suffices to prevent them from laying
their eggs. This property has been utilized in arboriculture. For this
purpose a mastic is prepared, with 1 part of fat and 2 parts of
chloride of lime in powder, and a ring of this preparation applied
round the trunk. Accoi'ding to Muhlberg, it suffices to suspend on the
tree a small basket filled with chloride of lime. Needless to say the
chloride of lime must be renewed as soon as it ceases to emit any more
h}^ochlorous acid.

47. Sulphate of Lime, CaSO^. — Preparation. — Gypsum, or
plaster stone, is a natural, crystallized sulphate of lime, CaS0^2H.20.
It is found in large quantities in the Trias and Permian. These
deposits are the result of the evaporation of ancient selenitic waters and
are met with in Morvan, Jura, Saone, Loire, Aveyron, Nievre, Gard,
and also in the environs of Paris, around Enghien. Crystallized sul-
phate of lime is rapidly and almost completely dehydrated at about
120'' C, being converted into plaster of Paris, which contains no water
but which I'etains the property of easily taking up its water of crystalliza-
tion once more when again moistened. This pi-ecious property is lost
if the gypsum is heated to 160° C. To obtain sulphate of lime com-
mercially the plaster stone is piled up at the quarry mouth in rude
arches under a shell made from combustible material, or in special
furnaces. The blocks must leave between each other interstices of
sufficient size to allow the flame of wooden faggots lit in the lower
part to pass. A very moderate fire is kept up, which penetrates the
mass slowly and dehydrates it. The plaster so obtained is pulverized
in mills and preserved out of contact with moisture.

Properties.— Sulphate of lime is slightly soluble in water ; 1 litre
of water at 0° C. dissolves 1"9 grammes ; at 38" C. 2"14 grammes ; at
99° C. 1"75 grammes ; it is much more soluble in hydrochloric acid.

Action of Sulphate of Lime. — Its action is due to its hygro-
scopic power and its fine division, which asphyxiates the insects by
penetrating into the respiratory passages.

Use of Plaster^ as a Manure. — Known to the Greeks and the
Eomans. Manuring with j)laster has been in current use, especially
since the eighteenth century. Franklin was one of its most zealous
advocates. The effect produced on certain plants by sulphate of
lime is so violent that scientists are not yet quite agreed as to the
explanation. Plaster contains two elements necessary to plants,
sulphuric acid and lime ; by supplying these two substances to the
soil plants necessarily thrive better than if deprived of these two ele-
ments. Although plaster cannot be regarded like lime as capable of
changing the physical and chemical composition of the soil, it, however,
restores to the soil in a soluble form the sulphuric acid and lime re-
moved by crops. The effects of plaster may thus make themselves felt

^ The author does not difi'erontiate between )j;ypsum and plaster but uses the
lenn jddtre throiit,'hout. To follow him it will lie well to bear in mind that in all
probability when he refers to plaster as a manure he means {gypsum, and when he
refers to plaster as an insecticide he means plaster of Paris. It is a pity that writers
on agricultural chemistry too often lose sight of the fact that superphosphate con-
tains naturally about 50 per cent of sulphate of lime in addition to what i.-: added
as a " reducer ". — Tb.

CALCIUM SILPHATE. 155-

even on calcareous soils when the latter is deficient in sulphuric acid.
If we calculate the amount of sulphuric acid removed from the soil by
crops we get the following figures per hectare: 5 '8 kilogrammes for
grain crops, 6"1 kilogrammes for leguminous seed crops, 14"1 kilo-
grammes for leguminous fodder crops, 7 kilogrammes for industrial
plants, 43*4 kilogrammes for root plants, 12 kilogi'ammes for tubers.
These amounts of sulphuric acid must therefore be returned to the
soil, as well as the other elements recognized as indispensable to
vegetable life. The analyses of the ash show that all plants have not
such an affinity for salts containing sulphuric acid ; thus plaster does
not produce the same effect on different crops. Plastering, which is
excellent for leguminosse, is of less value to cruciferae, tobacco, flax,
hemp, millet, and only slightly improves cereal crops. On the other
hand, plastering is capable of quintupling the crops of leguminous
fodder plants, such as lucerne, sainfoin, trefoil, and tares. Plaster has
thus an indirect action on the composition of the soil in rendering
soluble and assimilable for plants the compounds in the soil which
contain potash. The property which sulphate of lime possesses of
rendering the potassic compounds diffused through certain soils soluble-
has been recognized by Peters. Deherain has shown that when
plaster is added to the soil the formation of sulphate of potash is
induced, and it is found that trefoils manured with plaster contained
more potash in their ashes than the check samples. The sulphate of
potash forms in contact with the carbonate of lime which encloses and
renders the humic matter insoluble, carbonate of potash, which dis-
solves the humus. Owing to this action plaster is especially favourable
on soils rich in humus. But argilo-calcareous and silico-argillaceous-
soils, impermeable, humid, and cold vitiate this action. Plaster can
thus not only improve the crops which require its constituent elements^
lime and sulphuric acid, but likewise those which require potash or
humus. It acts, therefore, with advantage on soils rich in humus or
well-manured ground. Applied in large doses along with good manur-
ing plaster gives excellent effects in vine-growing. It is the chemical
analysis of the soil and that of the ash of plants which can alone
furnish information as to the necessity for plastering and on the
quantitj'^ to spread on the fields, for the proportions of plaster to use
in all soils cannot be given exactly. Muntz and Girard advise massive
doses at distant intervals owing to the comparative solubility of sulphate
of lime. On the other hand, they recommend only to make
plastering really useful to the growing plant at the moment of spread-
ing. This treatment will, therefore, be every two years for hardy
leguminous plants, such as lucerne ; for meadows, which form part of a
rotation, plastering is only done when their turn comes round. When
clover is grown with a grain crop it is better not to plaster the gi-ound
until after the gi-ain crop has been harvested, and not at the time of
sowing the seed so that the treatment may only benefit the leguminous
crop. As already said, it would likewise be well for the vine-grower
to use plaster along with abundance of manure. The average dose
per hectare is 400 kilogi-ammes the first year and 200-300 kilo-
grammes the following year. The most favourable time for plastering

156 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

is in the spring, preferably at the time the young buds begin to grow ;
it is done under cover by dusting the fields as regularly as possible.
Working thus the plaster has the further advantage of guaranteeing
the young plants so covered against the rigours of late frost. Plaster
used in arboriculture is regarded as an injurious manure causing the
fruit to rot.

Use agfainst Late Frosts. — The adhesion of plaster and its siccative
power permit its use against the late frosts of spring. The " powder-
ing " used for some years in France and very much in vogue in Italy
may entirely preserve the vine against late frosts so dreaded in viti-
culture. By means of a sulphurator the plaster is spread as an im-
palpable powder on the vines at the time frosts are feared. In Italy
plastering is associated with the treatment for the mildew of the vine
oidium, using a mixture containing ^ of sulphide and § of plaster
(wood ashes and lime are also used for the same purpose in Italy).
Ouvray advises to utilize this same process against frost to preserve
flowers, or the very delicate young fruit of fruit trees ; powdering is,
therefore, done say a little before flowering or immediately afterwards.
Powdering forms an economic and efficient protection against frost
and may find numerous applications in the culture of marshy land.

Use against Fungi. — Sorauer advises abundant manuring with
plaster to prevent the rotting of roots due to the development of the
most diverse fungi, such as Armillaria mellea, Quellet, Fihrillaria
xylothrica, Linh., Bliizoctinia violacea, Tul. ; this manuring has some-
times given good results.

Botrytis cinerea,'^ Pers. (grey rot of the vine). — Sorauer advises the
use of plaster in the same condition as slaked lime in fine powder.
As soon as this dreaded disease appears, plaster is sprayed on the
fruits ; the fruits are thus protected, for the fine layer of plaster which
covers them prevents the fungi from finding on the surface of the
grape a propitious soil for their development. Eecommended tor the
first time by De la Bathie, experiments made in the South of France
have not given the good results described.

Use against Insects. — Plaster having no caustic action can only
act as an asphyxiant. Owing to its extreme fineness, it is introduced
through the stagmata into the respiratory organs of insects, where
under the influence of moisture it hydrates, swells, and causes death.
Without being mortal to certain larvae, it annoys them very much and
keeps them away from plants. Plaster is used with much greater
success against altises. Hcdtica mnj)elophag'Us, Guer. (altise of the vine).
— So that the effect may be perfect, it is necessary to powder the vine
so that the plaster is projected on to the lower part of the leaves, for
it is there that the larva) and insects are. Brocchi greatly advises its
use. But it is not the altise of the vine alone which may be com-
bated in this way, the most diverse altises succumb or are driven
away owing to its use.

Haltica ncb/dosa, L. (Cassida nebulosa). — Doering advises the use of
plaster against this larvic as well as for the caterpillar of Noctua gamma.

'The conidia of Sclerotina Fuckeliatia, De Bary, — Te.

CALCIUM PHOSPHIDE. 157

Plusia gamma, L. (silver Y moth). — The caterpillars of this Noctua
abandon plants treated by plaster.

Melolontha vulgaris (cockchafer). — Poli recommends to kill this-
larva to plough in 8 cwt. of plaster per acre along with the cruciferous
plants grown for this purpose as intercalated crops. Plaster does-
not, however, act as such, but owing to the sulphuretted hydrogen
evolved by the fermentation in presence of oi'ganic matter.

Hyper a variabilis (beet weevil). — Plaster renders the same service-
as lime in destroying the larvae of this insect in lucerne fields. It
suffices to throw a certain amount with the shovel on the infested
plants. The larvie of the saw-fly succumb by powdering them with
plaster as well as with lime (Taschenberg).

Snails and Slugs. — Plaster used like lime destroys these mollusca.

Boclents. — Eodents are often destroyed by plaster. It is spread
on a saucer and covered with a layer of flour, a second saucer is filled;
with water. The rodents begin to eat the flour, of which they are
very fond, then the plaster. When they go to slake their thii-st the
plaster swells and agglomerates in their stomachs, causing death.

Sulphite of Lime, CaS032HoO. — Preparation. — By treating
milk of lime or chalk beaten up with water by sulphurous acid.

Properties. — Sulphite of Hme only dissolves in 800 times its weight
of water, but it is very soluble in sulphurous acid with which it forms-
calcium bisulphite.

Use. — Dufour tried sulphite of lime against the De7natoj)hora
necatrix, Hartig. (white root rot), but he did not find it effectual
J. de Sokolnicki used with success against the Botrytis cinerea, Pers.
(grey rot of the vine) a powder of the following composition : alumed
plaster 20 lb., bisulphite of lime 10 lb., Portland cement 15 lb.,
hydraulic lime 20 lb., green vitriol 35 lb. This powder used on vines
from 8 May and during flowering kept the grapes free from rot.
It is, moreover, known that bisulphite of lime destroys moulds because
it is regarded as the best disinfectant for cellars infested with mould.
It is also used to destroy the cryptogams which infest dairies, and
for the preservation of beer. It is to be remarked that the mixture
used against the black rot does not act solely through the bisulphite
of lime, but rather by the alum.

48. Calcium Carbide, CaC^. — Preparation. — By acting on an
intimate mixture of quicklime and powder, with the high temperature
of the electric furnace.

Properties. — It forms hard, compact scoriaceous masses without
smell in dry air. In moist air it gives off an alliaceous odour.
In contact with water it disintegrates and decomposes into hydrate-
of lime and acetylene.

Use. — See acetylene.

49. Calcium Phosphide, Ca^Po. — Preparation. — By passing the
vapours of phosphorus over sticks of chalk heated to redness.

Properties. — Calcium phosphide decomposes into water and lime,,
and into phosphuretted hydrogen, a poisonous gas.

Use. — Mouillefert used this substance with the object of destroy-
ing the phylloxera. For this purpose he exposed some roots infested

158 INSECTICIDES, FUNGICIDES, AND WJIED KILLERS.

by this insect in a 2-litre flask. Then he introduced 0"2 grammes of
calcium phosphide which slightly moistened gave 20 cubic centimetres
of phosphuretted hydrogen. This atmosphere contained 1 per cent of
asphyxiant gas, and was capable of killing the phylloxera in fourteen
hours. The numerous trials which were made on plants in pots and
on the large scale led Mouillefert to the following conclusion : —

Phosphide of calcium by the phosphoretted hydrogen which
it gives off in decomposing, may kill the phylloxera when the insect
is exposed to its action in an open, short-necked bottle, although,
however, this substance may be much less energetic than potassium
cyanide and carbon disulphide. But used on phylloxera-infected
vines, in pots or in vineyards, this phosphide has, so to speak, no
action on insects, which is probably due to the deleterious gas being
rendered harmless by the air and by the soil which burns it, and con-
verts it into products without action on the phylloxera.

50. Arsenite of Lime, CaoAsoO,,. — Preparation. — The paste of
arsenite of lime used to destroy injurious insects is made by dissolving
1 lb. of white arsenic in 2 gallons of water, and running into the
solution a milk of lime containing 2 lb. of lime. The mixture is then
heated for half an hour then thinned to make 100 gallons ofbouillie.
The arsenite of lime formerly used was the residue from the manu-
facture of magenta ; it consisted largely of arsenite and arseniate
of lime, and was sold under the name of London purple. As it
was partially soluble in water it was necessary to add to it to
render it harmless to plants an equal amount of quicklime under the
form of milk of lime. In America they have even used a paste con-
sisting of 60-120 grammes of London purple and l-5-2'5 kilogrammes
of lime in 100 litres of water. ^

Properties. — Arsenite of lime is insoluble in water. The pre-
cipitate is light and keeps in suspension much better than the arsenite
of copper. It has the advantage of being cheaper than Scheele's green
and emerald green (Paris green), this is especially so as regards London
purple, but the latter is variable in composition and its action on insects
is compiratively weaker. Arsenite of lime owing to its insolubility in
water is much more harmless to plants than arsenite of copper.
Whitehead found the following doses harmless : —

45 grammes of pm-ple in 100 litres for apple-trees. ^

50 ,, ,, pear and cherry-trees.^

00 „ „ the plum, hazel, and cherry-trees. ^

The bouillie made with an excess of milk of lime is, so to speak, harm-
less to plants.

Use. — Arsenite of lime is used wherever arsenite of copper is
capable of destroying injurious insects. Arsenite of lime has the ad-
vantage over arsenite of copper that it may be associated with eau
celeste (p. 260 et seq.) without dissolving therein. The bouillie thus
obtained is one of the most efficient in simultaneously combating
the following injurious insects and fungi : —

' Note by Translator.— Gninnuiisi per 100 litres = parts by weight per 100,000^
parts by volume or lb. per 10,000 Imperial gallons.

CALCIUM ARSENITE. . 159

Fusicladium dcntriticum, Fuckel (apple scab) ; Carpocapsa pomo-
nella (pyralis of the apple, codlin moth). — The efficient bouillie con-
tains London purple or arsenite of lime 0*050 per cent, copper
carbonate 0-45 per cent, ammonia 0-5 per cent. After six sprayings
made on 25 March, 1, 15, and 20 May, 26 June, and 14 July, Halstedt
obtained 47"6 per cent of sound apples and 3'46 per cent of wormy
apples, against 30 per cent of sound apples and 6-7 per cent of wormy
apples. The same result was got by a mixture of bouillie bordelaise and
London purple. Carrol by three sprayings on apple-trees, the first
soon after flowering, the two others at three weeks' interval, obtained
apples quite free from worms, whilst the check samples contained 60
per cent. The first spraying and the second w^ere done with a bouillie
containing 0"06 per cent of London purple and 1-2 per cent of lime,
the third with a bouillie containing 0*1 per cent of purple and 2 per
cent lime.

CHAPTEE IX.

MAGNESIUM CHLORIDE — MAGNESIUM SULPHATE (EPSOM SALTS) —
MAGNESIUM BISULPHITE — MAGNESIUM SILICATE (TALC SOAP-
STONE)— ALUM— ALUMINIUM SILICATE (CHINA CLAY)— ZINC SUL-
PHIDE—ZINC CHLORIDE— ZINC SULPHATE— ZINC BORATE— ZINC
SILICATE — ZINC FEEROCYANIDE — ZINC SULPHOCARBONATE —
CADMIUM SULPHATE.

51. Magnesium Chloride, MgClo. — Occurrence. — Naturally in
sea-water and as double salt in carnallite, KCUMgCl^, in the Stassfurt
mines.

Preparation. — By dissolving magnesia in dilute hydrochloric acid
and evaporating the solution, the magnesium chloride is deposited as
crystals.

Properties. — Very soluble in water, its taste is bitter. In medicine
it is used as a purgative ; it is more active than the sulphate of
magnesia. [Absorbs moisture from the air-deliquesces.]

Action of Magnesia on Plants. — Magnesium salts are comprised
amongst the alimentary substances indispensable to plants. Ch.
Dassonville found that plants watered with solutions of magnesium'
chloride first suffered a retardation in their growth and sprung up more
rapidly afterwards. Loew states that a certain amount of magnesia
and lime is required in the soil to obtain a maximum crop. Goessel
made artificial cultures to fix these proportions with various amounts
of these two oxides, and found that growth w^as at a maximum when
the media contained the lime and magnesia in the proportion of 0*4 to 1.
Katayama is of the same opinion as Loew in regard to the presence
in the soil of these two oxides ; he believes the ratio CaO : MgO as 2 : 1
as the most favourable for plants. Moller found that the absence of
magnesia in certain soils had a marked influence on the normal evolu-
tion of a plant. The pine, for example, suffers and its leaves turn
yellow at their extremities if it grows in a soil too deficient in magnesia..
It then suffices to water the tree with a solution of sulphate of magnesia,
oi- of chloride of magnesia, to re-establish the normal green coloration
of the leaves. The analysis of yellow leaves compared with those of a
normal green gave in the first case 0'279 per cent, in the second case
0'(307 per cent magnesia. Towards strong doses in the soil plants
behave very differently. Steglich studied the action of magnesium
chloride on plants ])y watering altei'nately with a solution of 30 and
15 per cent, and at the end of his investigations prepared the fotlowing
table : — ■

am

MAGNESIUM SULPHATE (EPSOM SALTS),

161

TABLE XX.

-Showing the Effect of 30 per cent and 15 per cent Solutions of
Magfiesitim Chloride on Plants (Steglich).

Crop.

SOper cent Solution.

15 per cent Solution.

Grain .

Suffered slightly

Did not suffer at all

Beet .

Did not suffer

Did not suffer

Potatoes

Killed

Killed

Peas

Killed

Unattacked

Trefoil ,

j Suffered slightly

Unaffected

Lupins .

Strongly attacked

Slightly attacked

Mustard

Killed

Destroyed

Charlock

Slightly damaged

Insensitive

Sorrel .

Unaffected

Intact

Horse-tail

Suffered slightly

Unaffected

Hitchcock and Carleton tried the action of magnesium chloride on
rust of cereals. They found that a 1 per cent solution prevented the
germination of the uredospores of Puccinia coronata, Corda, after
steeping for twenty-seven hours.

Use. — In strong doses magnesium chloride may be used to replace
green vitriol to destroy charlock in cereal crops ; it may act at the
same time as a manure. Trials made up to now with a 20 per cent
solution, at the rate of 35 gallons per acre, have given good results.
As a manure, it is recommended in pine nurseries to cure the yellow
leaves of the pines which show a deficiency of magnesia in the soil.

52. Magnesium Sulphate, MgSO^TH^O. — Preparation. — By
evaporating the waters of certain springs such as Epsom ^ in England,
and Seidlitz in Bohemia. But it is obtained more readily by attacking
dolomite by hot dilute sulphuric acid ; a mixture of insoluble sulphate
of lime is formed and soluble sulphate of magnesia which is separated
by filtration.

Properties. — Magnesium sulphate crystallines with 7 molecules
of water- ; 100 parts of water dissolve 26 parts of calcined magnesium
sulphate at a temperature of 0° C. and 72 parts at 100' C. It possesses
a bitter taste and is generally used in medicine, in which it is ad-
ministered as a purgative. In the vegetable economy it plays the role
of magnesium chloride, that is to say, dissolved in small amount in
distilled water it is capable of prolonging the growth of plants ; when
the plant is strengthened it becomes indispensable to it. In 1853 the
experiments of J. Pierre in the plain of Caen showed that magnesium
sulphate could render the same service as plaster in agriculture.

Use. — This product may be used to combat charlock in grain crops
in the same way as magnesium chloride. Magnesium sulphate was
recommended in 1852 to combat an insect injurious to beets termed —

A tomaria linearis, Steph. — Kuhn recommends to combat this insect
to immerse the beet-seed before sowing for twenty minutes in a steep

■ Hence the trade name of Epsom Salts. — Tn.

^ It is an efflorescent salt, i.e. loses most of its water of crystallization in a dry,
open atmosphere. — Tr.

11

162 INSECTICIDES, FUNGICIDES, AND WEED KILLRES.

of 5 per cent of sulphate of magnesia and 1 per cent carbolic acid.
Although of an efdciency which is highly contested, followers of this
practice include responsible experts (Marek, Pagnoul).

Feronosj)ora viticola, De Bary (mildew of the vine). — Solutions of
magnesia sulphate act on the spores of this fungus, but they are not so
poisonous as the salts of copper, so the experiments of Sbrozzi on
diseased vines gave only very imperfect results,

53. Magnesium Bisulphite, MgHo(S03)2. — Preparation. — By
treating magnesia stirred up in water with sulphurous acid.

Use. — Botrytis cinerea, Monilia frutigena, Comothyrium diplodi-
ella. — Istvanffi found that bisulphite of magnesia had the same action
on spores of these fungi as calcium bisulphite, of which an 0*5 per cent
solution acted in the same conditions eighteen times more energeti-
cally than a 10 per cent solution of bouiilie bordelaise. He advises the
use of a 0"4-0-5 per cent solution of bisulphite of lime or magnesium
to combat these fungi, a dose which can be increased to 1 per cent
without drawback.

54. Silicates of Magnesia. — Occurrence. — Two natural silicates
may be used against plant diseases; they are steatite, SSiOoSMgOo,
talc, 5SiOo4MgO. These two compounds are widely distributed in
nature.

Properties. — The silicates of magnesia are neutral, inactive bodies
insoluble in water. Owing to their fine division [and unctuosity]
steatite and talc show a very great adherence to plants.

Use. — Their extreme fineness and lightness render steatite and talc
highly appreciated for assuring to anticryptogamic substances a perfect
distribution on diseased plants. These two silicates, therefore, enter
into the composition of a large number of powders. Their role is to
dilute the active principle.

Uncinula Americana, How. — One of the chief uses of talc is in the
PoMcZre/ow to used against oidium and consisting of talc 90 per cent,
sulphur 10 per cent.

Peronosj)ora viticola, De By. — Steatite and talc are the most
appropriate substances for the preparation of copper powders used to
combat mildew. Sulpho-steatite consists of talc and blue vitriol. The
powder Fostit made at Antwerp contains 90 per cent of talc and 10
per cent of blue vitriol. These two preparations are those most used,
as owing to their lightness they penetrate vines better than any other
preparation.

Botrytis cinerea, Pers. (grey rot of the vine). — The pov/der which
has been most successful against this disease is that used by Dr.
Baretto, on the advice of the Baron de Chefdebien. It consists of talc
92 per cent, sulphate of alumina 3 per cent, sulphate of lime 4 per
cent, green vitriol 1 per cent. This mixture should be applied by
copious dusting before and after flowering if it be desired to remove
mould ; if it be desired to arrest the grey rot it is necessary to apply
this treatment every ten to twelve days after the disease appears.

According to recent ti'ials talc does not play any active role in this
preparation ; the active agent is the sulphate of alumina ; the sporicidic
property in this special case is superior to that of blue vitriol. But

ALUM. 163

the mechanical action of the talc must play an important part in this
preparation, as Jean Burnat has obtained as excellent results as Baretto
with the following preparation which did not contain sidphate of
alumina : cement 20 per cent, soapstone 30 per cent, hydraulic lime
50 per cent. Burnat uses this mixture in copious powderings after
previously moistening the diseased vines with a solution of soft soap.
These two preparations are the only ones which, with that of Sokolnicki,
have given satisfactory results in the treatment of grey rot of the
vine.

55. Alum, Al,3(S04)K.^S0424H.O. — Preparation. — Ordinary
alum is a double sulphate of alumina and potash. To prepare alum
pure clays are cilcined in a reverberatory furnace and then pulverized
and mixed with 40 per cent of sulphuric acid, 52' B. The mixture is
kept for several days at a temperature between 60° and 80° C, at the
end of which time the silica is deposited; the alumina is dissolved as
sulphate of alumina, which, decante I and mixed with sulphate of potash,
produces crystals of alum in the form of regular octahedra.

Properties. — Alum is a colourless salt of a sweet and astringent
taste, much more soluble in hot water than in cold. Alum solutions
have a slight acid reaction.

Action of Alum on Plants. — The vine does not stand this product
and dies if it be watered with a 5 per cent solution of alum (Mouille-
fert).

Action of Alum on Fungi. — Kuhn examined in 1872 the action
of an aluLu solution on the diseases of cereals produced by the fungi
Ustilago and Tilletia. After fifteen hours' action on the spores some
were still capable of germinating. According to the laboratory tests
of Eavaz and Guirand aluminium sulphate has a decided action on
Botrytis cinerea. This action is more evident than that of blue vitriol,
which is almost nil ; whilst, according to Millardet, the spores of
Peronospora viticola are killed by a solution of 3 in 10,000,000, those
of Botrytis cinerea still develop in a solution of 3 in 1000 of blue vitriol.
Action on Insects. — Alvood found that a 3 per cent solution and
even a 9 per cent solution does not kill cabbage grubs and lice.
Neither does it kill the larvae of the gooseberi-y saw-liy, Nematus ven-
triculoaus, Kl.

Use. — Botrytis cinerea (grey rot of the vine). — Amongst the sub-
stances recommended to combat this fungus two preparations have been
recommended and given good results ; they both contain alum or sulphate
of alumina. Sokolnicki's contains 20 per cent alumed plaster [alumed
plaster is obtained by adding 10 per cent of alum to plaster beaten up
with water and reheating it], that of Baron de Chefdebien 3 per cent
of aluminium sulphate. [The composition of both these mixtures has
been given under calcium bisulphite and talc] The two compositions
were successfully used in Brazil and in the department of the Gironde,
and their efficacy is undoubted, yet De la Bathie got no result by using
a bouillie containing 0 "5 of alum or sulphate of alumina and a little lime.
Sckizoneura lanigera, Hausm. (woolly aphis). — Alum has been
advised and frequently used for a very long time to combat this louse.
Some results were got by a solution of 2 per cent alum and 4 per cent

164 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

soda. Mohr advises a mixture containing 4 per cent alum and 5 per
cent amylic alcohol (fusel oil) to destroy larvae without down at the
moment they are hatched from the winter egg [Nov. -Dec.]. But this
mixture does not seem to kill eggs and adults. The role of amylic
alcohol in the destruction of these larvae is not unimportant, for no
appreciable result was got in recent trials made with concentrated
solutions of alum alone. This method is, moreover, contested by
Muhlberg. Advised by Radan in 1872 to combat the phylloxera
Mouillefert found the dose of 100 grammes of alum (say 3^ oz.) per
stock without action on the insect but apt to kill the vine.

56. Silicate of Alumina (clav). — Occurrence. — Pure silicate of
alumina is known as kaolin (" china clay ") and " plastic clay " ; mixed
with carbonate of lime it forms potters' clay.

Properties. — Mixed with water, clay forms a supple, plastic, and
unctuous paste.

Use. — In virtue of its special properties clay is used to guarantee
the bark of trees against the bites of leporides or to asphyxiate xylo-
phagous insects. For this purpose it is mixed with cow-dung and often
with ox-blood or curdled milk The following insects inter alia may
be got rid of in this way : —

Agrilus sinuatus, 01. (burn-cow of the pear-tree). — To prevent
the burn-cow from laying its eggs the trunks and branches of the tree
are coated with potters' clay ; to fight the larvae and asphyxiate them in
their burrows the whole of the bark must be coated with a mixture of
potters' clay and cow-dung, and a band of cloth applied on this coat.
Goethe found this treatment good. It can also be used against scolytes
and bostriches such as Scolytus Pruni, Eatzeb. (scolytus of the plum),
Scolytus rugulosus, Koch (rugose scolytus), Tomiciis dis])ar, Fbr. (bos-
triche different). To protect fruit trees against these three insects the
trunk and branches are coated with a mixture of lime and clay.

Cocliineals. — To kill cochineals a very old method consists in
coating the trees invaded with the following composition : Clay, soot,
cow-dung, sulphur beaten up with water to a pasty consistency.

Rabbits. — To prevent rabbits from nibbling the bark of fruit trees
these are coated at their base with one of the following preparations :

(1) Potters' clay 2 lb., cow-dung 2 lb., ox-gall 1 lb., bullock's blood
1 lb. This mixture is stirred up with purin to a pasty consistency.

(2) Potters' clay 2 lb., curdled milk 2 gallons, blood 2 gallons, purin
G gallons. (3) Asafetida 1| lb., blood 8 gallons, with sufficient cow-
dung and clay to give a smooth paste. The odour of these coatings
being very repugnant to rabbits keeps them at a distance.

57. Zinc Sulphide, /nS. — Preparation. — By adding sodium sul-
phide to a solution of zinc sulphate. The white precipitate is filtered
and washed.

Properties. — Zinc sulphide is insolul)le in water.

Use. — Fairchild used a zinc sulphide bouillie, made by precipitating
sulphide of zinc by a solution of liver of sulphur against (1) PJiyllo-
sticta s])li(eropsidea, Pj. and I'], (spots of the leaves of the chestnut) and
against (2) Eiitovisaporinm viaculnt niu (spots of the leaves of the pear-
tree). Result in (1) appi'eciable, in (2) nil.

ZINC SULPHATE. 165

58. Zinc Chloride, ZnCL. — Preparations. — By dissolving zinc
clippings [or zinc scrap] in dilute hydrochloric acid. By evaporating
the solution the anhydrous salt, butter of zinc, is obtained.

Properties. — Zinc chloride is a white deliquescent solid soluble in
water in all proportions ; exposed to air it liquefies rapidly.

Action on Fungi. — Zinc chloride behaves like zinc sulphate
(Wuthrich). All remarks made on zinc sulphate (farther on) apply to
zinc chloride. Tried comparatively against copper compounds on the
Peronospora viticola, DeBy., by Sbrozzi, its effect was inferior to blue
vitriol. By the use of a 1 per cent solution the uredospores of Puccinia
coronata, Corda, are checked in their development [Hitchcock and
Carleton].

59. Zinc Sulphate, ZnSO^, 7HoO (white copperas).— Prepara=
tion. — By roasting crude zinc sulphide at a low temperature a mixture
of zinc and iron sulphates is formed which is dried and calcined to de-
compose the sulphate of iron. The mass is then lixiviated with hot water,
filtered, and the solution of zinc sulphate evaporated to crystallization.

Properties. — Zinc sulphate forms colourless crystals with a bitter
styptic taste. It dissolves in 2\ times its weight of water at 15° C. and
in its water of crystallization at 100° C. It is used in medicine as an
emetic in doses of 8-15 grains, as a collyria, gargle, and injection.
It is used as a disinfectant ; it acts like sulphate of iron.

Action of Zinc Sulphate on Plants, — Sulphate of zinc shares
the property that the sulphates of iron, copper, and other salts have of
stimulating the growth and vitality of the plant if absorbed in small
doses and of being poisonous in large doses.

In 1869 Eaulin described this action on Aspergillus niger. Eichards
then Ono examined this property of zinc sulphate on Aspiergillus niger,
Penicillium glaucum, Ssixd the eilgae Protococcus and Chroococcus, Sttgeo-
clonium and Hormidium, and determined the stimulating action of zinc
salts. As soon as the dose is higher than that required for stimulation,
these salts retard or prevent the formation of spores. The dose re-
quired to stimulate algae is much less than that required to stimulate
fungi. Kanda made similar trials with Pisum and found that the
stimulating action of zinc sulphate is produced when the nutritive
solutions do not contain more than 0-00000015 to 0-0000030 per cent
of zinc sulphate. Nobbe, Bassler, and Will found that peas and maize
died in three days if the nutritive medium in which they grew contained
1 per cent of zinc as nitrate of zinc. This poisonous action is much
less pronounced and sometimes does not occur in darkness (Baumann).
Many plants, chiefly conifers, bear without injury 1 per cent sulphate
of zinc without dying but afterwards show great defects in growth
(Baumann). Konig found in fact 2-78 per cent of zinc in the ash of
beech and maple stunted by slow poisoning by zinc. There even exist
plants which seek media rich in zinc minerals for their development ;
these are Viola lutea (forma calaminaria) a,nd Thlaspi alpestre. Zinc
salts behave like blue vitriol and other ' poisonous salts in nutritive
solutions where the roots are in direct contact with the soluble salts;
these are poisonous in comparatively small doses because the plants
readily absorb them in large quantities, but the same plants cultivated

166 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

iu the soil bear strong doses because they are there converted into in-
soluble salts, the roots of which only absorb small quantities incapable
of producing a poisonous effect. Haselhoff and Gossel found that the
presence of 0-235 per cent of zinc oxide in a soil does not injui-e vegeta-
tion but that zinc sulphate in the same dose calculated as oxide was
poisonous.

Action of Zinc Sulphate on Cryptogamic Parasites.— Accord-
ing to comparative experiments by Wuthrich zinc sulphate acts like
green vitriol, and in the same doses as the latter destroys the spores of
different fungi. It is thus like green vitriol 10 times less poisonous
than blue vitriol and 100 times less active than mercuric chloride,
the three salts being used in solutions containing their chemical
equivalents.

Phytophthora infestans, De By.— The conidia treated by a 0'0143
per cent solution are weakened, and after fifteen hours in a 0'143 per
cent solution destroyed. The zoospores of this fungus are stunned in
a minute in a 0 143 per cent solution and killed in fifteen hours.

Peronospora viticola, De By. — The conidia are weakened by a
0-00143 per cent solution. Their growth is stopped by 00143 per cent
solution.

Puccinia graminis. — The uredospores and the aecidospores are
arrested in their growth by the action of a 0'143 per cent solution.

Ustilago Carbo (smut). — The growth of the conidia is retarded by
a 0'143 per cent solution, but they are not killed by a 1"430 per cent
solution. According to Madame de Ponsard, spores immersed for four
hours in a 1 per cent solutioii partially germinated.

Claviceps purpurea, Tul. (ergot). — The conidia are not killed by a
1'43 per cent solution.

Use. — Peronospora viticola, De By. (mildew of the vine). — Follow-
ing experiments by Wuthrich who showed that the action of zinc
sulphate on the spores of this fungi is evident though comparatively
weak, Guocdenovic made experiments with a 1'0-1'5 per cent zinc
carbonate with a bouillie made by mixing solutions of zinc sulphate and
sodium carbonate. The results were not comparable with those ob-
tained by the Burgundy bouillie nor the bouillie bordelaise. Passerini's
experiments also showed that a bouillie with a zinc sulphate basis had
no curative action, hke copper bouillies.

Ustilago. — Advised by Mme. de Ponsard in 1 per cent doses for dis-
infecting seed-corn, zinc sulphate did not give the results expected.
Loverdo regards its prophylactic action as doubtful and inefficient.
He regards the salt as unfit to replace copper salts.

Phylloxera vastatrix, Planch. — Mouillefeit completely destroyed
the phylloxeras on an infested root by steeping it in a 1 per cent solu-
tion of zinc sulphate.

6o, Borate of Zinc, ZnB^O-. — Preparation. — By precipitating
a solution of zinc sulpluite by [a sohition ofj borax. On mixing the
concentrated solutions a gelatinous precipitate is obtained.

Use. — Galloway examined on rust the effects of a bouillie made by
precipitating 133 grammes of zinc sulphate by a concentrated solution
of 133 grammes of borax and making the whole up to 15 lities. Oats

ZINC SULPHOCARBOLATE. 167

and summer wheat treated on 6, 16, 20 June and 5 July were
free from rust and gave an excellent yield in grain, 284 grammes
against 240 grammes on the check plot of the same size. He re-
garded this preparation as efficient against rust. Fairchild was less
fortunate. The experiments undertaken by him to prevent —

PhyUosticta spharojJsidea, E. and E. (spots of the leaves of the
chestnut), Entomosporium viacnlatum (spots of the leaves of the
pear, leaf scald), gave a negative result.

6i. Silicate of Zinc. — PhyUosticta spharojysidea and Entomo-
sjJorimn maculatum, Lev. — Silicate of zinc bouillie produces no per-
ceptible effect.

62. Zinc Ferrocyanide. — The zinc ferrocyanide bouillie examined
by Fairchild although perfectly adherent had no appreciable effect
against Ento'mosp)orium maculatuvi, Lev. (spots of the leaf of the pear-
tree), whilst injuring the leaf.

63. Sulphocarbolate of Zinc. — The phenol sulphonic salt of zinc
cannot prevent Peronospora viticola (mildew), nor replace copper pre-
parations. All attempts to replace copper salts by zinc salts have
failed, because the latter have no salutary effect except in large doses
with which plants cannot be put in contact ; besides as the sporicidic
capacity of zinc salts is not superior to iron salts, they can in no
way act similarly to copper salts, and can never replace these in their
numerous prophylactic and therapeutic applications.

64. Cadmium Sulphate, CdS0^4H.,0. — Preparation. — By
roasting cadmiferous blends, or by dissolving cadmium oxide or car-
bonate in sulphuric acid.

Properties. — Cadmium sulphate is very soluble in water ; it
dissolves in a little less than double its weight of water ; its crystals-
are colourless. By dissolving sulphate of cadmium by an excess of
soda or by milk of lime, a white gelatinous cadmium hydrate is
obtained soluble in ammonia.

Use. — Peronospora viticola, De By. (mildew of the vine). — Cad-
mium sulphate was tried comparatively against copper sulphate, like-
wise a bouillie made from cadmium sulphate and milk of lime was tried
against bouillie bordelaise. Eavaz and Bonnet made in 1898 five
sprayings on vines, 14 and 25 May, 22 June and 3 August, and
some days before the fall of the leaf, with (1) 0"5, 1"0, and 2 per
cent bouillie ; (2) a 0*5 and 0"25 per cent solution of sulphate of
cadmium on a neighbouring plot ; (3) spraying with bouillie bordelaise
of 0"5, 1"0, and 2-0 per cent, and (4) a solution of copper sulphate of
0*25 and 0*5 per cent. They found that preparations with a cadmium
basis of equal strength had the same anticryptogamic effect as those
with a copper basis. Analogous experiments by Sbrozzi, and by
Guocdenovic, did not give such favourable results ; they found the
action of preparations with a cadmium basis always inferior to corre-
sponding preparations with a copper basis, and regard cadmium salts
as incapable of replacing copper salts in the struggle against anti-
cryptogamic diseases of plants. Passerini also found that cadmium
salts are incapable of replacing copper salts, because their anti-
cryptogamic action is too weak.

CHAPTEE X.

IRON PEROXIDE — IRON BOUILLIES — IRON SULPHIDE — IRON
CHLORIDE — GREEN VITRIOL — POTASSIUM FERROCYANIDE —
PRUSSIAN BLUE.

65. Hydrate of Sesquioxide of Iron (Ferric Hydrate), Fe.2(H0)g.
— Preparation. — By precipitating a solution of sulphate of iron (green

vitriol) by caustic alkali or by milk of lime.

FeSO, + 2K0H = Fe(OH)., + KoSO,.
FeSO, + Ca(0H)2 = Fe(OH)._, + CaSO,.

The hydrate of the protoxide of iron, ferrous hydrate, a greenish-white
precipitate which is first formed, oxidizes afterwards in contact with
the air, and is converted into hydrate of sesquioxide of iron ferric
hydrate, which is yellowish-brown.

2Fe(0H), + H,0 + 0 = Fe,(OH)e.

The bouillies used against plant diseases were made from 1-15 lb.
of green vitriol and 4^-8 lb. of quicklime per 10 gallons of water.
Their preparation is similar to the bouillie bordelaise. The green
vitriol is dissolved in 5 gallons of water, and the quicklime made into
milk of lime is run with 5 gallons of water into the green vitriol
solution with suitable stirring. The bouillie should have a slight
alkaline reaction.

Properties. — The ferric bouillie has the physical properties of the
bouillie bordelaise and behaves like the latter, both as to its adherence
and the solubility of its precipitate by atmospheric agents.

Action of the Ferric Bouillie on Plants. — There exists between
the iron bouillie and sulphate of iron (green vitriol) the same relation
as between bouillie boidelaise and sulphate of copper (blue vitriol).
The sulphuric acid of the sulphate of iron being neutralized is in an
inert and insoluble form ; the sulphate of lime does not scorch the
leaves like green vitriol solutions exceeding 2 per cent. But the
hydrate of sesquioxide of iron engulfed in the sulphate of lime, and in
an excess of lime, has not however such a rapid action on the chlorotic
condition of the plants treated as solutions of green vitriol. Dufour
has shown that iron placed in contact with the plant in this slightly
soluble foi'm is none tbe less absorbed wherever the leaf is touched
by the ferruginous bouillie. Chlorotic plants after several sprayings
with this bouillie show green places at all points of contact. Never-
theless, the effect of these bouillies is nil if a strong dose of sulphate

(168)

IRON SULPHIDE. 169

of iron be not used. Whilst 1 per cent solutions of ferrous and ferric
salts produce a stimulating effect on the plant, it requires 3-15 per
cent of hydrated oxide of iron to produce the same effect, and it is
necessary to apply these bouillies in sprayings several times a year.
Lagarrique recommends to apply them every fifteen days. Several
scientific observers have imagined that the stimulating effect of copper
bouillies was to be attributed to the sulphate of iron present in greater
or less amount in commercial sulphate of copper, in their opinion
pure copper sulphate free from iron would have no salutary effect on
the plant and could not be absorbed by it without injuring its health.
The mixed bouillies of sulphate of iron and sulphate of copper re-
commended to accentuate the stimulating effect of bouillie bordelaise
are : —

Pellegrini's, 1 lb. of blue vitriol, 1 lb. of green vitriol, 1 lb. of quick-
lime in 10 gallons of water. AderhokV s, 19 lb. of blue vitriol, 1 lb. of
green vitriol, 20 lb. of quicklime in 100 gallons of water. Sorauer's,
19^ lb. of blue vitriol, ^ lb. of green vitriol, 20 lb. of lime in 100
gallons. Goucdenovic, who examined the action of these bouillies
compared with those of pure sulphate of copper, found they were in
no way superior as stimulants. One cannot understand in fact how
a copper bouillie containing only 0'l-0"05 per cent green vitriol as
hydrated oxide of irou can produce any stimulating effect when it is
necessary to use 3 per cent of this oxide to produce the same effect
with a ferx'ic bouillie.

Action of Ferric Bouillies on Fungi. — The hydrated oxide of
iron has no pronounced toxic action on the spores of fungi, and cannot
in any case replace the hydrated oxide of copper in the struggle
against cryptogamic disease. Although green vitriol be ten times less
toxic for plants and fungi than blue vitx'iol, these relations do not exist
between the corresponding iron and copper oxides. The numerous
expei'iments to replace the costly cupric bouillie by bouillies with a
hydrated oxide of iron base have given no result in the struggle against
plant diseases due to parasitic fungi.

Phytophthora infestans, De By. (potato disease). — Iron bouillies
have been more especially tried against this disease as substitutes for
bouillie bordelaise. Giltay's experiments with a bouillie of 1 per cent
green vitriol and ^ per cent of lime gave negative results. Sempotowsky
tried stronger bouillies, but they had no more effect in diminishing or
preventing the potato disease than the 1 per cent solution. Steglich
also points out the bad effects on potatoes by treatment with iron
bouillies containing 2-4 per cent of sulphate of iron.

Gloeosporiuni ampdophagum, Sacc. (grape rot). — Pellegrini ob-
tained very good results in overcoming this disease with a bouillie
consisting of 1 lb. of blue vitriol, 1 lb. of green vitriol, and 1 lb. of lime
in 10 gallons of water.

E ntomosporium maculatum, Lev. (spots of the leaf of the pear-
tree, leaf scald). — Fairchild did not cure this disease by using a bouillie
consisting of 0*6 per cent of hydrated oxide of iron prepared by pre-
cipitating green vitriol by caustic potash.

66. Sulphide of Iron (Ferrous Sulphide), FeS.^. — Preparation.

170 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

— By precipitating green vitriol by an alkaline sulphide. It forms a
black gelatinous powder.

Properties. — Insoluble in water. Eeadily oxidizes in air.

Use. — Galloway tried against fhe rust of oats and wheat a bouillie
of sulphide of iron obtained by precipitating 28 lb. of green vitriol by
24 lb. of liver of sulphur and thinning down the whole to 100 gallons.
In spite of four sprayings, 6, 16, 20 June and 5 July, the result
was negative, as might have been foreseen, looking to the insolubility of
iron sulphide in atmospheric agents. Fairchild used this bouillie
against Entomosporium maculatum (spots of the leaf of the pear-tree,
leaf scald) and Phyllosticta sjyhceropsidea, E. and E. (spots of the leaf
of the chestnut). The experiments showed that it was not capable
of circumscribing or preventing these diseases, but that it caused
serious damage to the leaves of the plants treated.

67. Iron Chloride, FeoCly5H^O. — Preparation. — By dissolving
iron in aq^ia regia or by passing 'a current of chlorine into a solution
of protochloride of iron (ferrous chloride). The solution concentrated
by boiling yields on cooling orange red crystals of ferric chloride.

Properties. — Very soluble in water. Its solutions coagulate
blood and act as hemostats in medicine.

Use. — Galloway found a 1 per cent solution sprayed every ten days
on wheat fields preserved them against rust. The treated plot showed
no rust. The check plot showed twelve plants attacked. This action,
which greatly resembles the action of soluble salts of copper, is ap-
parently only due to the exceptional vigour of the cereals due to this
treatment. Moreover, Hitchcock and Carleton have shown that a
1 per cent solution of perchloride of iron can only interfere slightly
with the vitality of the spores of Puccinia coronata, Corda (crown rust
of oats), and Wuthrich has proved that it requires a 10 per cent solu-
tion of perchloride of iron to kill the uredospores of Puccinia graminis,
Pers. (linear rust). At the same strength as the persulphate of iron,
ferric chloride is directly assimilable by the leaf and acts as a powerful
stimulant of the vital functions of the plant. As a tonic, perchloride
of iron may be of use in the struggle against the diseases of plants,
but it cannot be ranked as an aaticryptogamic substance capable of
killing the spores of fungi.

Entomosporium macidatum (spots of the leaf of the pear), Phyl-
losticta s])]ueropsidea, E. and E. (disease of the leaf of the chestnut). —
Fairchild used to combat these two fungi a mixture of 1 per cent of
ferric chloride, 1 per cent of carbolic acid, even 0-5 per cent of each of
these substances. Without any action on the development of these
diseases, the two mixtures seriously scorched the leaves.

Chlorosis. — Stevignon made comparative trials with perchloride of
iron and green vitriol, and found that the action of the perchloride was
much more rapid than that of the sulphate. He obtained the best
results by making incisions in the bark of the stocks, and coating the
wounds with a 40 per cent solution of perchloride of iron ; fifteen days
after treatment the chlorotic vines were quite green. Comi)arative
trials with liydrochloric acid itself have shown that it is the iron which
is the active element and not tlie hydrochloric acid.

GREEN VITRIOL. 171

68. Sulphate of Iron, syn. Green Vitriol, FeSO^TH^.— Pre=
paration. — (1) By roasting iron pyrites and lixiviating the product.
(2) By slow oxidation in the air of pyritic shale. (3) By dissolving
iron turnings [or scrap iron] in dilute sulphuric acid. By concentrating •
the solution to 40° B., it abandons green crvstals responding to the
formula FeS0,7H,0.

Properties. — Solubility, 100 parts of crystallized green vitriol dis-
solved in 143 parts of water at 15° C:, and in 30 parts of water at
]00° C. To prepare solutions of green vitriol it is best to use boiling
water ; they must then be kept in closed vessels, for the salt is readily
converted into a slightly soluble basic sulphate of sesquioxide of
iron in contact with the air ; green vitriol has a styptic, astringent
taste.

Action of Green Vitriol on Green Plants. — ^Iron is invariably
present in all green plants, but often in very small quantity. As to
its distribution in the plant, it may be said to be present more especially
in all the green parts, without being, however, entirely absent in
other parts of the plant. Iron may be considered as necessary to
plants as to man and animals. Its absence produces a pathological
condition known as chlorosis. Culture experiments have shown that
the plant cannot develop itself normally in absence of iron. The
necessary quantity is very small, and 2-5 milligrammes suffice for a
cereal plant (Knop). Sachs induced artificial chlorosis by cultivating
plants in a soil in which iron was excluded. Experiments made in
nutritive solutions show that the seed may germinate and the young
plant grow normally in the absence of iron ; the small quantity of iron
present in the seed amply suffices in the beginning to allow a normal
growth, but later on a fresh portion of iron becomes indispensable or
the plant gets into a bad state. Knop proved that the amount of iron
in a gland was sufficient to prevent chlorosis of the young oak for two
years. The plants which succeed best are those treated with a 0'15 per
cent solution of green vitriol ; a stronger dose than 0'2 per cent is often
injurious. The absence of green in plants deprived of iron has given
rise to the idea that iron takes part in the formation of that colour, but
we are far from knowing exactly what is its role in the formation of
chlorophyll. Formerly it was believed that iron entered into the com-
position of chlorophyll as in the haemoglobin of the blood, but this
opinion is not entertained at the present time. The analysis of purified
chlorophyll and the demonstrations of Armand Gautier and Hoppe-
Seyler prove, in fact, that iron does not enter into the chemical composi-
tion of the green parts of plants. Certain recent discoveries, however,
lead us to suppose that there exists along with chlorophyll substances
of analogous composition containing iron. Iron is not only indispens-
able to the normal formation of chlorophyll, but it has a favourable
action generally on the life of the plant. Green vitriol applied to the
surface of a green orange becomes yellow by the absence of iron salts and
restores to it its primitive colour. Brogniart, Gris, and Treviranus have
already described this and produced drawings made on the leaves to
show the local action of green vitriol. Millardet and Knop believe that
like blue vitriol green vitriol acts without penetrating the leaf, for

172 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

they were not able to find ponderable quantities in the organs cured.
Of a contrary opinion Dufour describes the absorption of these salts
by the surface of the leaf, and Weiss and Wiesner have shown that iron
which enters into the plant exists there in organic combination which
may have escaped Millardet and Knop. Frank, Kruger, and Vedrosi
regard green vitriol as equal to blue vitriol as a stimulant of the plant,
and believe that a very small dose suffices to produce a visible and
salutary effect. These two salts seem to act in quite the same manner
on plants with this difference, that copper salts possess an action ten
times stronger than iron salts taking into account their different
chemical equivalent. Shrubs which annually undergo the classical
treatment with bouillie bordelaise, likewise those which are treated with
solutions of green vitriol, acquire a greatly increased vitality which in-
creases assimilation and a longer vitality which enables trees to preserve
their leaves in autumn much longer than those untreated. These facts
prove that iron is the active chemical agent in the formation of
chlorophyll, stimulating its functions, and in that way also it becomes
the indirect provider of starch, sugar, and cellulose for the plant.
Without iron, oa the other hand, the plant eventually dies because
assimilation of carbonic acid becomes impossible. The role of iron there-
fore seems analogous to that of potassium, the absence of the latter
element also inducing the anaemia of plants. The substitution of iron
for potassium according to Griffiths' experiments would be very ad-
vantageous in the struggle against the cryptogamic diseases of plants.
Potash is very favourable to the development of fungi, whilst green vitriol
is injurious. The substitution of green vitriol for potassic manures
whilst giving the same physiological results would have the effect of
circumscribing the cryptogamic diseases of plants. Desjardin had al-
ready observed the great resistance of plants treated with green vitriol
to disease. Chavie-Leroy certifies that the simultaneous use of green
vitriol and gypsum preserves grain crops from rust and laying ; it
diminishes ergot, the fall of the flower of the vine, stops the canker of
apple and pear trees, and causes the gum of stone-fruit trees to dis-
appear. Like gypsum, green vitriol used in the soil acts on the latter
from a physical and chemical point of view. Boussingault agrees with
Sachs, Stohmann and Knop (1) that it oxidizes the organic matter of
humus and hastens its decomposition ; (2) that it fixes ammonia in the
soil ; (3) that it aids the plant to absorb the phosphoric acid in the
soil. Thenard and Joulie state that phosphate of lime is converted
in the soil, in contact with oxide of iron, into phosphate of protoxide of
iron soluble in water charged with carbonic acid ; the ferric phosphate
formed would afterwai'ds be reduced by the organic matter. In 1859
Knop was already convinced of the action of iron as a vehicle for
phosphoric acid. Like gypsum, green vitriol effects a radical change
in the soil by the decomposition of the insoluble minerals which con-
tain potash. Green vitriol forms an equivalent of a soluble potash
salt and thus renders the richness of the soil available for the plant.
It follows that green vitriol having always a beneficial action on crops
is thus capable of increasing the yield and that chiefly a^ regards
plants to which potash is necessary. Where carbonate of lime is the

GREEN VITRIOL. 173

cause of the chlorosis, green vitriol has a very intense ameliorative
action and must be used in large doses. It acts on the soil by de-
stroying the soluble carbonate of lime and on the plant by revivifying
the juices and imparting to them new vigour, for the excess of carbonate .
of lime exhausts the acid juices of the root v^hich then cease to act.
It follows from Vernet's experiments that the use of green vitriol in
5 per cent solution with 5 per cent of sulphuric acid gives still better
results ; this acid decomposes the carbonate of lime and enables the
green vitriol to come in contact with the roots as such. Chlorosis
was in this way made to disappear in soils containing 19-25 per cent
of carbonate of lime. As to the form under which the iron ought to
be applied to the roots it is not definitely settled, neither do we know
what salt of iron is most easily assimilated by plants and under what
form the iron is conveyed the most easily from cell to cell. Ferrous
salts [of which green vitriol is one] are always, it is supposed, converted
into ferric salts in contact with the oxygen of the air in the soil.
However, many facts appear to contradict this opinion ; the most differ-
ent ferrous and ferric salts are capable of remedying the pathological
condition produced by a deficiency of iron. These salts spread by
copious spraying on the roots act before the ferrous salts (green vitriol,
etc.) can have had the time to be converted into ferric salts. If the
ferric salts are more active on the other hand, the ferrous salts render
the same service in a longer time. It must be mentioned that green
vitriol ferrous sulphate must be used in a much more dilute condition
than ferric sulphate. The form most favourable for artificial cultures
is the phosphate of iron which the roots assimilate after rendering it
soluble. The following observation speaks in favour of the absorption
of iron under the form of ferrous salts : plants which live in marshes,
rich in green vitriol, possess great accumulations of iron as ferric
oxide in certain of their organs. (Traija natans contains in its ash
68-6 per cent of ferric oxide.) These deposits cannot be otherwise
explained than by the precipitation by oxygen of soluble ferrous salts
being conveyed through the plant and so converted into insoluble ferric
salts. According to Mokrzecki it is possible that green vitriol may be
absorbed by the plant, and conveyed by the sap. The rapid and
radical cure of chlorosis by injection into the trunk of dilute solutions
of green vitriol which in no way affect the good working of the circula-
tion is a convincing proof.

It follows, therefore, that iron may be supplied to the plant under
any form, and that ferric salts as well as ferrous, organic and inorganic
salts of iron are capable of curing chlorosis. (Gris has shown that the
sulphate, tartrate, malate, and acetate of iron in the dose of 0*5 per
cent when they are used in sprayings on the leaf produce an analogous
effect.) It must be admitted, in fact, that the roots can convert the
iron into a compound fit to circulate through the organs of the plant,
and to produce the remarkable physiological effects described above.
If a certain dose be exceeded tbe iron becomes injurious, if given in
excess it is mortal. Different plants behave very differently with the
same dose of iron. Whilst certain plants suffer with a dose of 0*05
per cent of green vitriol in an artificial culture medium, trees may sup-

174 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

port iQJectioQ3 of a 0*25-0'5 per cent solution of the same substance.
The injurious action of green vitriol depends greatly on the nature of
the plant to which it is applied. Aqueous plants very fond of water
are much more sensitive than plants not fond of \Yater. Mosses, for
■example, feel the action of green vitriol much more- than cereals.
A strong dose of green vitriol has a specially injurious action on the
vital functions of the plant ; thus Mayer found that, used for grain crops,
it hindered the grain from forming in the ear.

TABLE XXI. — Showing the Number of lb. of Green Vitriol tchicJi Wheat, Rye,
Barley, and Oats, respectively, can bear per 16C0 lb. of Soil.

Vitriol.

Grain Crop.
Wheat .

Lh. of Green
4

Eye

Barley .
Oats

10

20
20

AVhilst barley is unable to form its grain if the dose of green vitriol
contained in the soil is above that given in Table XXI, oats resist
better. The injurious action of green vitriol is explained by the fact
that in presence of tannins and certain other analogous products it is
readily decomposed into insoluble organic compounds and sulphuric
acid. The latter causes at a certain concentration the corrosion of the
cellular tissue and disturbs the osmotic phenomena of the cell-walls.
Deherain and Grandeau in France, Wrightson, Griffiths, and Munro
in England, have shown that 60 kilogrammes per hectare {-^ cwt. per
acre) may always be used with advantage, whilst a dose of 250 kilo-
grammes per hectare (2 cwt. per acre) was often injurious.

Action of Qreen Vitriol on Fungi. — Iron is not only necessary
to green plants, but a small quantity of this product would also seem
to be required by parasiiic plants with no chlorophyll. The latter are,
however, more sensitive to green vitriol, which, like blue vitriol, is often
a violent poison for them. As to spores it has been shown that the
injurious action is connected with the penetration of the green vitriol
through the exterior membrane. If this penetration does not occur
the action is nil, if it occurs vitality is arrested. Iron like copper may
be found in the interior of the spores by means of certain reagents.
To determine if green vitriol has penetrated the spores, these, after
steeping in tbe green vitriol solution, are washed for fifteen minutes,
then they are placed in a bath of yellow or red prussiate of potash and
a little hydrochloric acid. If the iron has been absorbed the spore
becomes blue. Wuthrich found this absorption in all cases where the
spore was dead after immersion in vitriol. According to the experi-
ments made up to now on fungi, green vitriol acts identically with blue
vitriol, which, howeve)-, is the more energetic. Wuthrich concludes that
the doses of green vitriol and of blue vitriol which produce the same
action on the spoi'es of different fungi are proportional to the chemical
equivalents of these salts, gi-een vitriol, these proportions preserved
being ten times weaker.

The following are the amounts of green vitriol and blue vitriol
required to stop the growth of spores : —

GREEN VITRIOL.

175

TABLE XXII. — Sltowmg the Strength of Solutions of Blue and Green Vitriol
Required to Kill Spores of

Phytophthora infestans
Peronospora viticola
Ustilago carbo

Puccinia graminis .
Claviceps purpurea .

Green Vitriol,

Blue Vitriol,

Per Cent.

Per Cent.

0139

00125 Wuthrich

0139

0-0125

1-39

0-125

5 00

0-5 Boiret

1-39

0-125 Wuthrich

13-9

0-0125

From the above table spores have not the same resistance to green vitriol.
Whilst some are very sensitive others are very resistant, and support doses
poisonous to certain green plants. The quantity required to destroy some
of them is so great that there can be no question of their destruction on
the nurse plants by green vitriol, for the latter plants would be killed as
well as the parasites. That is why blue vitriol can never be replaced
by green vitriol in fighting the cryptogamic diseases of plants. When
the parasites can be attacked without injury to the plant, green vitriol
is an excellent cryptogamic ; its use in the treatment of anthracnose is
a striking example. xVlthough green vitriol be less utilized in agri-
cultural medicine than blue vitriol, its use against the cryptogamic
parasites of our cultivated plants is a necessity in many cases. Where
its action is not sufficient to destroy the spores of the fungi by impart-
ing greater vigour to the plant, it enables it to contend more readily
against its parasites. Galloway has shown that sprayings with green
vitriol absolutely incapable of killing the spores of rust, nevertheless
almost entirely eliminated this disease from the grain crop. The same
applies to the Claviceps purpurea (ergot), a fungus reputed to have a very
great resistance to green vitriol, the ravages of which may, however,
be considerably diminished by spraying therewith. Each time that
green vitriol has been used as a manure for cultivated plants, or sprayed
thereon, improvement has resulted as well as a considerable diminution
in diseased plants.

The Action of Green Vitriol on Insects. — Green vitriol has no
action on hard-skinned insects, for it is not absorbed so long as the skin
is intact ( farisot). The mucous membranes, on the other hand, may
absorb poisonous doses ; taken through the mouth iron salts are violent
poisons. Amongst mammals a small amount of iron salt may cause
death by stopping the action of the heart (Eabuteau). Ferric salts
are more dangerous than ferrous salts, because they coagulate the
soluble albumen and thus arrest the circulation of the vital liquids.
Ferric salts ought, therefore, to be regarded as violent poisons. The
action on insects does not make itself felt unless absorbed by the mouth,
in eating the leaves sprayed with iron salts.

Use of Green Vitriol. — From time immemorial ferruginous
manures were used to improve crops. The Romans knew the good
e£fect of iron and utilized as a manvu-e certain soils, rich in oxide of

176 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

iron, still in use in Italy under the name of " Terra rosa ". In
Champagne, likewise, pyritic shales have beea used in vineyards for
centuries. In the North of France, Picardy, Ardennes, Normandy,
and in Flanders, there are used for the same purpose the ashes of
Picardy which contain much iron pyrites. These are not only used
to double the yield of meadows but also to strengthen cereals. As-
tonished at the results obtained by the use of these ferruginous
manures, Eusebe Gris, Professor of Chemistry at Chatillon sur Saone,
tried to ascertain the cause. His experiments showed that the green
vitriol formed by the slow oxidation of the pyrites in the soil was the
active cause. As far back as 1840 he recommended green vitriol to im-
prove crops and to contend against chlorosis. The researches of his
son, Arthur Gris, and Knop enabled the function to be explained and
extended its use. Gradually it entered common use to contend against
the cryptogamic diseases of plants. Green vitriol may be used in
different ways ; in cultivation on the large scale it is spread as crystals,
or in 3-5 per cent solution, by watering carts ; it may also be sown by
hand as a fine powder intimately mixed with dry earth. To cure trees
of chlorosis and parasitic diseases, the incorporation of green vitriol in
the soil may be replaced by spraying on plants or even by injection
into the trunks of the trees. Used in that way the action of green vitriol
is felt much quicker than when it is absorbed by the roots.

Use of Green Vitriol as a Weed=killer. — All plants being more
or less sensitive to the action of green vitriol, it is evident that by
using a determinate quantity of this salt all the plants which have
a less resistance can be eliminated from a given crop. Thus grain
crops possess a surprising resistance to this product, and it is possible
to destroy all the weeds in a field of grain without injuring the crop.
Steglich has treated different adult plants with a 20 per cent solution
of green vitriol and obtained the following results : Grain crops are
not attacked ; peas, trefoil, linseed, charlock suffer from this treatment ;
potatoes, beets, haricots, lupins are greatly damaged ; mustard is
killed. Stender confirms Steglich's results. He treated cultivated
plants with a 15 per cent solution of green vitriol by spreading it at
the rate of 4 hectolitres per hectare (35"2 gallons per acre) and found
no damage on cereals, blue lupin, red trefoil, colza, poppy, and carrot,
but moderate damage on peas, flax, and serradelle (? saw wort) ;
finally much damage on millet, rape, white mustard, potatoes, and
beet. Twenty-five per cent solutions of green vitriol destroy almost
all weeds ; however, horse-tails, comfrey, nettles, and carex i-esist
perfectly. The action of green vitriol solutions is especially deadly to
young plants when they have only three to four leaves ; if the adult
plants resist concentrated (15-20 per cent) solutions, young plants cannot
stand much smaller doses. Strong solutions of green vitriol are not,
therefore, necessary when used rationally, and, as Dumont found, a 5 per
cent solution suffices in most cases, especially when it is a case of destroy-
ing young mustard. The older the plant to be destroyed the stronger
should be the solution of green vitriol ; thus mustard in flower requires
a 10 per cent solution, adult mustard a 15 per cent solution. Gwallig
recommends for the destruction of this plant a 7-10 per cent solution.

GREEN VITRIOL. 177

Linet agrees. To destroy charlock, Hitier estimates that 10 hectohtres
of a 10 per cent solution per hectare suffice (88 gallons per acre
suffice). Weiss also recommends this same quantity, but of 10-15
per cent strength. Schultz concluded after numerous tests that it was
necessary to use 15 per cent solutions, although young weeds already'
suffer with a 2-3 per cent solution. It is necessary to apply this
treatment when the plants have only three or four leaves ; it is true that
cereals suffer slightly when young even when only a 7 per cent solu-
tion is used, but they soon revive and only grow afterwards with in-
creased vigour. To destroy young charlock and mustard 5-10 per
cent solutions suffice, but to destroy all weeds 15 per cent solutions
must be used. Wallflower requires a 10 per cent solution in the begin-
ning of vegetation. Before spreading green vitriol on a field the age
and sensitiveness of the plant must be taken into account. It is best to
proceed thus : The solution of green vitriol is conveyed to the neighbour-
hood of the field and sprayed by a spraying machine or a watering-
cart. The best time to treat weed-infested fields is just before the weeds
rise up into stems, i.e. when they have four to six leaves. It is well
to spray in fine weather, which by concentrating the solutions on the
surface of the leaves increases the effect. To free fields of grain chemi-
cally from charlock, advantage may be taken of the dew to spread finely
pulverized green vitriol at the rate of 200-300 kilogrammes per hectare
(176-264 lb. per acre). If rain intervenes after green vitriolizing, its
effect is lessened or destroyed. But even in that dose and under that
form green vitriol is not so efficient as a 4 per cent solution of blue
vitriol at the rate of 800-1000 litres per hectare (70-88 gallons per
acre). A man is capable of vitriolizing a hectare (24^ acres) a day ;
10 hectolitres (220 gallons) of green vitriol solution, that is to say,
100 kilogrammes (2 cwt.) of this salt suffice per hectare (88 lb. in 88
gallons per acre). The total cost of the treatment may be estimated
at 10 francs (8s.) the hectare (say 3s. 2^d. the acre). There must be
no hesitation in applying this treatment, which while freeing the fields
from encumbering weeds supplies it with a new element as an aid
to growth. From Steglich's comparative trials green vitriol has no
advantage over such metallic salts as muriate of potash, nitrate of
soda, and sulphate of ammonia, which whilst destroying weeds are
good manures. However, we believe, that green vitriol is superior to
these salts by its anticryptogamic properties.

Destruction of Moss. — 1. On Meadows and on Laivns. — Mosses
which invade all lawns, and diminish the yield of many meadows,
may be readily destroyed by green vitriol. Their affinity for water
is such that they absorb in large quantity the green vitriol distributed
in solution. The extreme limits to employ per hectare ai-e 250-500
kilogrammes of green vitriol (2-4 cwt. per acre). It is well to
spread the distribution over several applications, especially when the
meadow is badly choked up with moss. Noffray advises not to go
beyond 100-150 kilogrammes per hectare (88-132 lb. per acre) in each
of these applications. If green vitriol is used in crystals, it is necessary
to choose tine weather to spread it after a strong dew, during or after
rain. If green vitriol is used in solution in watering-carts, any time

VI

178 INSECTICIDES, FUNGICIDES, AND WEED KILLEES,

may be chosen ; however, the best result would be obtained by applying
the treatment after cutting the grass. Mosses infest poor and moist
soil ; after their destruction by green vitriol the cause of their presence
should be obviated by manuring and draining [and liming].

2. On Trees. — To free the trunks of trees from mosses and lichens,
which are so many refuges for parasites, they are scraped with the
decorticator-moss-eradicator, then the trunk and branches are coated
with a solution of green vitriol. The stronger the solution the better,
but the strength of the green vitriol may be considerably reduced by
adding a corrosive acid, such as sulphuric acid ; in such conditions a
10 per cent solution of green vitriol containing 2 per cent of sulphuric
acid acts as well as a 40 per cent solution of green vitriol. By add-
ing 2 per cent of blue vitriol to this solution, the tree is freed from all
spores of fungi.

3. On Boofs. — A 10 per cent solution of green vitriol spread on
moss-covered roofs completely destroys the moss. But green vitriol
cannot be used where there are zinc gutters, for the latter will be
corroded by contact therewith.

Destruction of Dodder. — Dodder is a plant without chlorophyll,
which, like fungi, is more sensitive to the action of iron than green
plants. But if the filaments of the young plant do not resist 2 per cent
solutions, on the other hand a 10 per cent solution is required to kill the
adult plants, which often kills or injures the nurse plant. Schribaux's
tests have shown that dodder seeds, owing to their thick tegument,
resist 20 per cent solutions of green vitriol, and that even after steep-
ing for fifty days their vitality is not lessened. Immersion in water
for fifty days : 19 percent germinated. Immersion in 20 per cent solu-
tion of green vitriol for fifty days : 12 per cent germinated. Dodder
specially invades trefoil and lucerne fields, plants equally sensitive to
10 and 20 per cent solutions of green vitriol ; needless to say the treat-
ment should be applied before fructification and should not extend
over the whole field. It suffices to treat the parts attacked. Stronger
solutions of sure effect can thus be used. By saci"ificing a few square
yards of the crop the spread of the plague can be averted. The
following is the best method of working : After mapping out the
dodder spots, comprising within the surface to be treated a radius of
a metre beyond that where the filaments are apparent, the spots are
cut with the scythe. It suffices then to water the diseased spots with
a 2 per cent solution of green vitriol if the treatment be carried out
in May ; on the contrary, if in July a 10 per cent solution will be
required. Needless to say if one watering be not enough, the opera-
tion is repeated a few days afterwards, and watering must be copious
so as to reach the matted filaments. Ponsard and Clerc advise this
treatment to be done in the spring.

Use of Green Vitriol to Combat the Diseases of Plants. —
Chlorosis. — In certain conditions unfavourable to the plant, chlorophyll,
the active agent of assimilation, does not develop normally. A con-
dition of languor follows, which is manifested by a yellowish or reddish
coloration of all the green parts of the plant. This pathological con-
dition is known an jaundice, when it is caused by a want or excess of

GEEEN VITRIOL. 179

water ; etiolation, when it is produced by the want of light ; chlorosis,
when it is due to the want of iron. (This condition has some analogy
with the anaemia of man.) But the absence of potash may induce the
same phenomena. An excess of carbonate of lime in the soil,^ in-
sufficient nourishment, a defective condition of the roots,^ a patho-
logical condition of the whole plaat,^ insufficient heat, are so many
causes which may produce a chlorotic condition of the plant. Hence
it is easy to understaad that iron cannot always remedy these diseased
conditions. It can only be of real service where the chlorisis is due to
a want of iron, or to an excess of lime,'* and of minerals rich in un-
assimilable potash. In jaundice and etiolation it would be of no use.
In the case of a tree attacked by chlorosis, the cause must above all
be carefully determined and ii-on only used well to the purpose.
Where chlorosis is due to a want of iron, the use of iron salts is to be
prescribed, and they will yield always a green coloration in a short
interval as well as give new vigour to the plant. The dose to use
varies in different cases. There are numerous methods which are
more or less effective, and which act more or less rapidly.

1. Application of Green Vitriol to the Soil. — The most usual
method is to spread green vitriol in crystals around the tree in doses of
1-2 kilogrammes (2-2-4:-4 lb.) per tree, and preferably after a heavy rain.
The dose is of no great matter ; an excess of green vitriol would not
injure the tree, as it is converted into insoluble derivatives in the soil.
Used thus its action is slow but durable. To get a more prompt effect
it is better to act thus : A circular trench is dug round the tree, at a
distance from the trunk, varying with its size, from 20-40 inches
and a width of 8-12 inches. After well watering it, 1-2 lb. of
green vitriol in crystals are sprinkled into it, or better still, a mixture
of manure and green vitriol in powder ; the soil is filled back into the
trench and copiously watered. It is preferable to dig out a basin
around the diseased tree and to fill in 10-20 litres (2-2-1-4 gallons)
of a 10 per cent solution of green vitriol (Tome) or a 5 per cent
(Guirand). By repeating this treatment several times, every eight
days, the cure will be rapid and complete, and the action will be
more prompt as the tree is more in sap. The dose to use
which in certain cases may be very weak (Sorauer advises a solution
■of 100 grammes of green vitriol, 30 grammes of saltpetre, and 20
grammes of phosphate of potash per tree), ought, on the other hand,
to be very stiong if the soil is calcareous. When carbonate of lime
is the predominating cause of chlorosis, as is the case with trees
with seed pips, such as the pear, and more especially the vine,

' Viala has shown that a vine in pot treated with 2 kilogrammes (4-4 lb.) of lime
became chlorotic in forty days.

- Damentjew having found different acari on the roots of trees attacked by
chlorosis attributed that disease to their presence.

*Roux believes he observed micro-organisms in plants attacked by chlorosis.

■* According to Dementjevv's experiments an excess of carbonate of lime would
only indu';e chlorosis when there was a lesion of the roots, a healthy root being
only able to absorb a normal amount of lime ; barium chloride as well as common
salt produce chlorosis under like conditions ; it would thus be the acari which he
found on the roots which by producing lesions were the prime cause of the chlorosis
of the tree.

180 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

the amount of green vitriol used must be greater the richer the soil
is in carbonate of lime. If the normal quantities to be spread on the
soil of a vineyard generally vary between 300 and 1500 kilogrammes
per hectare (264-1320 lb. per acre), these quantities should rise to 4-8
metric tons (3520-7040 lb. per acre) when the soil is highly calcareous
(Viala). This dose is spread in winter on the soil and buried by
hoeing. Vernet recommends, so as to diminish the dose of green
vitriol and to increase the action, the use of a 5 per cent solution
acidulated with 5 per cent of sulphuric acid. At the rate of 2 litres
per stock the results were perfect, and did not injure the roots.
Sulphuric acid by converting the carbonate of lime into sulphate of
lime lets the green vitriol penetrate more easily as far as the roots,
and prevents its conversion into insoluble carbonate of iron without
immediate effect on the plant. The treatment of chlorosis by vitriol-
izing the roots tends to disappear because it is slower than treating the
aerial part of the plant with green vitriol solutions.

2. Use of Green Vitriol on the Aerial part of the Plant. — (A)
As Spray. — Eusebe Gris was the first to find that by spraying the
leaves of a chlorotic tree with a 05 per cent solution of green vitriol the
leaves rapidly assume a green coloration, first on the spots in contact
with the green vitriol, then over all their surface. This process gives-
much quicker results than when the iron is absorbed by the roots,
but the effect is also more ephemeral, unless spraying is repeated
several times a year. It then forms an excellent method against
chlorosis. However, like blue vitriol, green vitriol in decomposing
liberates sulphuric acid injurious to plants and thus produces corrosions-
and scorchings which only the simultaneous use of lime can remove.
The amount of green vitriol to be used in spraying must, therefore, be
well estimated so as not to exceed the amounts recognized as harmless.
Two per cent solutions burn the leaves treated (Dufour, Sagnier, and
Mohr). Brunet and Delacharlony found that the vine did not suffer in
contact with a 2 per cent solution, but they recommend not to use the
latter except on adult leaves. In spring a 1 per cent solution must do.

(B) Use as a Coating. — This process is based on the absorptive
power of plant tissues in contact with solutions of metallic salts.
KassigLiier tried to make a radical cure of chlorosis of the vine by
introducing green vitriol in a strong dose into the sap. After pre-
liminary pruning in autumn at the fall of the leaf whilst there is still
a movement of the sap, the sections are coated with a 40 per cent solu-
tion of green vitriol ; a large portion of the iron is then absorbed. In
the spring the pruning of the vine is completed. This process has
given marvellous results, especially on vines growing in soils very
rich in lime, and it has replaced the process which consists in spread-
ing on the soil strong doses of green vitriol in the form of crystals.
But it is reco'j,nized that poisoning occurs with 50 per cent solutions,
but not with 40 or even 30 per cent solutions which prodi;ce the same
salutary effect. Thus Guillon recommends the use of 20 or 25 per
cent solutions for young and 30 per cent for adult vines. This method
which has numerous partisans has been used with the fourfold end in
view of (1) curing chlorosis ; (2) combating anthracnose ; (3) de-

9

GREEN VITRIOL. 181

stroying cryptogam ic germs ; and (4) preserving vines from frost. But
to attain this end, instead of only coating the sections the whole stock
must be coated from top to bottom with a 30-40 per cent solution of
green vitriol. This treatment, which is done in this case in the autumn,_
retards from ten to twelve days the exit of the buds and may thus pre-
serve the viae from late frosts. Used on the large scale in Cognac and
Charente this process gives mo^t precise and satisfactory results.
Andre has adapted the Eassiguier treatment to fruit trees. After
autumn pruning he coats the same day the sections and all the wood
with a 30 per cent solution of green vitriol. This process, very effec-
tive on young trees attacked by chlorosis, is not energetic enough for
large trees, on which it is necessary to decapitate the branches and to
make slight incisions in the bark of the base of these branches. By
means of a brush a 30 per cent solution of green vitriol is caused to pene-
trate as far as the sapwood. These coats should be applied at intervals
of eight days. Favourable results were got chiefly on cherry-trees, pear-
trees, and peach-trees ; the yield in fruit is much increased, and amongst
the latter the rust completely disappears. Green vitriol can thus be
entrained by the sap without injuring the plant. Very interesting trials
by Mokrzecki conducted thus confirm this fact : He pierced one or several
holes in the trunk of the tree and there introduced green vitriol in
crystals, then closed the holes with mastic. An average dose of 12
grammes suffices to suppress chlorosis.

(C) Use as an Injection in the Trunk. — The satisfactory re-
sults obtained by the extra-racinary nutrition of trees and by the
injection of nutritive salts into the sapwood of the trunk induced
Mokrzecki to hope to cure chlorosis by injection of solutions of green
vitriol into the sap. He pierced one or more holes of 1-1 "To centi-
metres (*-yV inches) in diameter in the trunk and injected 12 grammes
of green vitriol in 0"0o-0-25 per cent solution. So that the
solution may be entrained by the sap it is of importance to prevent
access of air ^ into the hole during the time it is being pierced.
To accomplish this it is necessary to proceed as follows : The
point of the centre-bit is passed through a metal tube which com-
municates by an india-rubber pipe with the reservoir containing the
green vitriol solution. By working the centre- bit the liquid forthwith
fills the space drilled out and thus prevents the access of the ambient
air. The reservoir is hung to a branch and the liquid thus introduced
under a certain pressure. The holes are pierced through the sapwood.
A tree with a diameter of 20 centimetres (8 inches) is capable of ab-
sorbing 8 litres (1| gallons) in twenty-four hours. As soon as the
operation is finished the hole is refilled with mastic. The most favour-
able time for this work is the months of March, April, or May, when
the sap is in motion. Trees attacked with chlorosis show from the
fourth day a greener colour in their leaves ; in ten days chlorosis is no
longer to be seen, and in three weeks the leaves are deep green. Trials
made on 840 trees leave no doubt of the efficiency of this treatment.
During his experiments Mokrzecki also observed that all the organs of

' The appliances formerly used by Bouchery, Hartig, Pichi, and Berlese allowed
A\r to penetrate which prevented the absorption of the liquid.

182 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

these trees were influenced favourably, the buds were more vigorous,
fruits more numerous, growth more rapid, and that especially if the
treatment was combined with extra- racinary feeding, which finds many
partisans nowadays. The same observer has pointed out that kermes
such as Diaspis fallax, Horv., of the pear-tree and Mytilaspis pomorum,
B., of the apple-tree were much less numerous and even disappeared
from the trees treated with green vitriol. It is the same as regards
the Gii7)i and the Fusidadium.

Cryptogamic Diseases of Plants. — Attempts have been made to
combat by green vitriol and green vitriol bouillies diseases capable of
being restricted by blue vitriol and cupric bouillies. Green vitriol being
much cheaper than blue vitriol this substitution would have had gi-eat
pecuniary advantage. Unfortunately, the dose to use being ten times
larger to produce the same effect, this advantage disappeared, and the
use of green vitriol was restricted to the parts of the plant which bear
this treatment. Used in the same strength as blue vitriol in spraying
leaves attacked by various diseases it does not produce the same salutary
effect. However, its action is not nil, and its stimulating power on the
vital functions of the plant causes the latter to suffer less from the
attacks of parasites, and often prevents their spreading.

Potato Scab. — Nijpels found that green vitriol spread on potato
fields appreciably diminished the scab of the tubers without com-
pletely preventing it.

Bacillary Gum of the Vine (Mai Nero). — The only remedy
capable of stopping the spreading of this disease is the radical
removal of all the diseased parts (Prillieux and Delacroix). The
wounds produced by pruning are coated with a concentrated solution of
green vitriol and afterwards covered with a mastic. Where contagion is
to be feared it suffices to coat the pruned sections to prevent the disease
penetrating by the wounds. Meunier practised winter coating in his
domain on every stock with a 50 per cent solution of green vitriol with
2 per cent of sulphuric acid. The effect was very satisfactory, the
parts which had previously perished were cured and contagion avoided.

Bacterian Disease of the Mulberry. — Euiter recommends the green
vitriol treatment. As soon as a branch appears attacked it is cut off in the
healthy part a few centimetres below the diseased spot. The cut branches
are burned on the spot, then the pruned section is coated with a 45 per
cent solution of green vitriol. Trees so treated grow in the same year
of treatment vigorous buds and next year show no trace of the disease.

Phytophthorainfestans, De By. (potato disease). — Green vitriol ex-
erts an energetic action on the conidia of this fungus and a 1 per cent
solution should produce an eflect on the disease. Tried as substitutes
for cupric bouillies, 1 per cent solutions of green vitriol used in two
sprayings, the first on 18 June, the second on 15 July, produced
no improvement. Peterniann obtained by this process the following
results : The plot treated gave 8-3 per cent of diseased tubers and 73
lb. of tubers. The check plot gave 11-3 per cent of diseased tubers
and 102 lb. of tubers. A strong manuring with green vitriol in the
spring will give such vigour to the potato plant that it will better
resist this disease.

GEEEN VITRIOL. 183

Peronospora viticola, De By. (mildew of the vine). — According to
Wuthrich the spores the most sensitive to green vitriol are those of
Peronosj)ora. A solution of 0'0139 per cent kills the conidia after
fifteen hours' immersion. The first trials to combat mildew were made
in 1882. Millardet recommended a mixture of 4 lb. of green vitriol
in powder, 20 lb. of green vitriol, and 20 lb. of plaster. A nursery of
2000 Jacquez attacked with mildew in the middle of June was treated
2 July in dry and hot weather. Success was complete ; the young
buds had not suffered, and they resisted the re-invasion of September.
Eeich found that the treatment for anthracnose is also a preventive of
mildew. This treatment which consists in coating the stocks with a
25-50 per cent solution of green vitriol before the buds begin to unfold
is used with success at Armeiiliere against the Peronosjwra. This
treatment is not always followed by the desired effect.

Ustilago (smut) and Tillctia (bunt). — Green vitriol has no action
on the spores of Tilletia Levis (Kuhn). Wuthrich showed by labora-
tory tests that a 1"39 per cent solution of green vitriol hinders the
development of the spores of Ustilago, and a 13'9 per cent solution
kills them. The trials of Boiret made by sowing the spores of brown
rust on object glasses placed in a moist chamber at 18°-20'' C.
gave analogous results. A certain number of spores still germinate
after an hour's immersion in a 5 per cent solution of green vitriol or
after four hours' immersion in a 2 per cent solution, whilst the spores
do not germinate in a 0*5 per cent solution of blue vitriol. Green vitriol
has, however, been used for a long time to disinfect seed corn against
smut and bunt. A 2-5 per cent solution of green vitriol was used
in which the seeds were left to macerate for six to twelve hours, after
which they were limed, then left to dry in the air. The results ob-
tained were not very satisfactory. Mathieu de Dombasle artificially
infected a portion of grain by agitation in a sack with the dust of brown
rust, then he treated the infected grain with green vitriol, blue vitriol,
and lime. After sowing he got the following results: —

TABLE XXIII. — Showi?ig the Remdts of the Experiments of De Dombasle on
the Disinfectio7i by Green Vitriol of Seed-Com Artificially Infected on
Purpose.

Percentage of
Infected Ears.

1. Check plot, grain not treated .....

2. Grain sown after two hours' steeping in a 1-2 per cent

solution of green vitriol ......

3. Grain sown after two hours' steeping in a 2-4 per cent

solution of green vitriol ......

4. Grain moistened twenty-four hours before sowing with

a 4 per cent solution of milk of lime ....

5. Grain steeped for one hour in a 1-2 per cent solution

of blue vitriol . .

6. Grain steeped for twenty-four hours in a cupric bouillie

of 10 per cent lime and 1-4 per cent blue vitriol

Per Cent.
486

469

570

470

8

2

184 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Although the actioa of greea vitriol on the grains of wheat is much
less injurious than that of blue vitriol, this action, ten times less
cryptogamicidic than the latter salt, forms no inducement to use it as
a substitute. Used ten tinier more concentrated than blue vitriol its
pecuniary advantages disappear. Henriot made interesting trials on
the pickling of seed-wheat. The seeds steeped for twenty minutes in a
1 per cent solution of green vitriol germinated quicker and more
uniformly, and produced more vigorous plants, than the unpickled
seeds sown in the same conditions. Besides the plants seemed less
sought after by insects than the check plants. On peas the increased
yield was 100 grammes more per square metre. Turnips also gave
an increased yield, and v/ere not attacked by the fly (altises). Henriot
recommends pickling cabbage seed, radish seed, turnip seed, peas,
haricots, salad, etc., seeds to secure quicker germination and a bigger
yield.

Puccinia (rust). — The uredospores do not germinate after fifteen
hours' immersion in a 13 "9 per cent solution of green vitriol. The
aecidiospores, more sensitive, do not germinate after immersion for the
same time in a 1"39 per cent solution (Wuthrich). Used by Galloway
to combat rust of winter wheat, green vitriol was found incapable of
restricting that disease, but used, in 0*5 per cent solution on young
plants before its appearance, this disease was considerably lessened.
Used as manure, green vitriol completely prevents this disease because
it imparts more vigour to the plant. The numerous experiments of
Phillipar and Sance in France, of Griffiths in England as well as those
of Saccardo, have shown green vitriol to be a preventive. The doses
to apply on the lai'ge scale do not exceed 2 cwt. per hectare, say 88 lb.
per acre ; this manure is spread on the soil in the spring the same time
as the seed is sown.

Polyporus (polypores). — Prillieux advises to destroy Pohjiwrus
fulvus, Fries, which lives on fruit trees, and particularly on the olive,
the same treatment for anthracnose. After having cut out the fungus,
the bark and wood already attacked is removed, then the bared surface
is moistened with a 50 per cent solution of green vitriol, rendered more
active by the addition of 2 per cent of sulphuric acid. The wounds
are afterwards protected against fresh infection by covering them with
a layer of tar. Sirodot advises this operation not to be done in
autumn, which is that of the fructification of the parasite, and to choose
warm dry weather as much as possible.

Exoasciis deformans, Fuckel (leaf curl of the peach). — By treating
peaches with green vitriol according to Eassiguier's method, and re-
peating it at intervals, Andre caused the rust to vanish completely.

Erysiphfictinwiimis, Wall, (mildew of the pea). — Deneuville advises
green vitriol as a pteventive used thus: Sow the peas and cover
them in April with a green vitriol in powder, then give the ground
a slight but uniform touch with the harrow. Excellent plants which
rise up well and free from blight are thus obtained.

Nectria ditissima, Tul. (canker of the peax% the apple, and the beech).
— Prillieux recommends, to kill this fungus, and to protect wounds
against its invasion, the process just described for the destruction of

GEEEN VITRIOL. 185

polypores and against anthracaose. All the parts of the wood attacked
and coloured around the canker muat be removed by cutting, for even
apparently healthy parts may contain ramifications ot the mycelium.
By carefully moistening these bared parts with the corrosive solution,
of green vitriol and sulphuric acid, the cankers are cured.

DasyscypJta Wilkommi, Hartig (canker of the larch). — Prillieux
recommends to destroy this fungus which belongs to the Pezizes the
same treatment as the Xectria ditissima.

Claviceps jjurjjurea, Tul. (ergot of rye). — The spores of this fungus
are those which resist immer.sion for the longest lime even in con-
centrated solution of green vitriol. Solutions of 1-10 per cent have
no action on them. In spite of that McAlpine recommends to
iprevent and combat this disease a 1-4 per cent solution. The spores
do not find on the cereals strengthened by this ferruginous treatment
the soil favourable to their growth, and the less number of diseased
plants is due to the improvement in their power of resistance of both
healthy and attacked plants.

Dematophora necatrix, Hartig (white root rot). — Dufour tested
comparatively the action of greea vitriol and blue vitriol on this fungus,
and found the latter much superior to the former. However, Beniling
and Behaix recommend green vitriol against rot of vine roots (Wurzel-
schimmel) where carbon disulphide and sodic fluoride had no action.

Bhizoctinia violacea, Tul. (rhizoctinia of lucerne and beet). — Bu-
back tried to contend against this fungus by spreading 1 kilogrammes
{8'8 lb.) of green vitriol on a plot of ground 10 square metres, then sow-
ing beets eight days later after burying the green vitriol. The result was
that the iron salt greatly stimulated the growth of the beets, increased
the sugar, and that the plot had only 28 per cent of diseased plants
against 47 per cent in the check plot.

Gloeosp)orium amjyeloj^hagum (grape rot). — Sulphuring and treat-
ing the vine with cupric bouillies have not circumscribed this disease
at the same time as the oidium and mildew. Anthracnose must be
treated by itself, and only winter treatment with green vitriol has
proved entirely satisfactory. Schuorf was the first to advise and use
50 per cent solutions of green vitriol to contend against this disease,
and Skawinski was the first to add to these solutions a small amount
of sulphuric acid to render the solutions more corrosive. This last
formula has given perfect results. Studied in different countries, this
mixture has undergone some alterations of no importance. Sorauer
advises a 40 per cent solution. Tome a 35 per cent, Ghirardi from
'0*5-2 for young shoots, so as to prevent scorching by stronger doses.
Bolley advises 50 per cent of green vitriol and 5 per cent of sulphuric
acid ; Galloway 6 per cent of green vitriol and 0'45 per cent of
sulphuric acid; Scribner 23'6 per cent of green vitriol, 6-6 per cent
of blue vitriol, and 1-9 per cent of sulphuric acid; Thomas 20 per
cent of green vitriol, 14 per cent of blue vitriol, and 12 per cent of
fat lime ; finally, Orillard 25 per cent of green vitriol and 10 per cent
of blue vitriol.

Contrai-y to the opinion of Berlese, who attributes the success of
these mixtures to their (free) sulphuric acid content, alone capable in

186 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

his opinion of sterilizing the cankers produced by anthracnose, green
vitriol employed pure is perfectly capable of giving excellent results ;.
moreover, it has the advantage over 10 per cent sulphuric acid solutions
of not scorching the buds, and only retarding their unfolding slightly.
If the addition of blue vitriol be not injurious, and if mixtures contain-
ing this product have given excellent results in the Haute-Garonne,
this salt is not indispensable, and adds to the cost of the treatment.
To-day 50 per cent solutions of green vitriol acidulated by sulphuric
acid are in constant use in the Bordelais ; they are included in the
annual treatment of vines in Medoc, and in all districts which suffer
from anthracnose. The green vitriol solutions are made thus :
50 kilogrammes (110 lb.) of green vitriol are placed in a wooden or
stoneware vat, then mixed with 1 litre of sulphuiic acid of 53" B.
Whilst stirring with a stick 100 litres (22 gallons) of hot water are run
into the receiver. The precaution of first mixing the green vitriol
crystals with the sulphuric acid is necessary to avoid projection of
corrosive liquid. The solution is applied hot to prevent crystallization
on cooling. The stock is coated with a big brush, or with a plug of
rags attached to the end of a wooden handle, then all the stock, the
stem, the arms, and the runners are soaked without respecting the eyes.
However, it is necessary to coat from below upwards so as not to-
scorch the buds ; it is also preferable to unbark the stock before using
this corrosive liquid. The operation should always be carried out
during the repose of vegetation ; it is a winter treatment which is best
done twice with fifteen days' interval ; the last operation takes place-
fifteen days before the opening of the leaf, that is to say, at the moment
the spores germinate. The best season is therefore the end of Febru-
ary or the beginning of March, but often this treatment is applied at
the moment the buds begin to open. After coating the wood should
become black. If rain ensue and this change has not taken place the
treatment must be repeated. Green vitriol solutions in no way attack
the buds, but none the less retard their opening fifteen days. The
districts where anthracnose prevails suffer much from frost, and this
retardation of vegetation is very beneficial to the vine. The operation
should be done in calm weather so as to avoid too great evaporation
of the solution. It takes 8-10 litres (1-76-2-2 gallons) of this solution
for 1000 stocks of vines. Spraying may be used with great advantage,
the work is done quicker than with the brush, but it involves the use
of tools with glass reservoirs. When anthracnose is developed during
plant growth, it is contended against by mixtures of sulphur and green
vitriol in powder ; this treatment stops the development of the spores,
but it should be renewed several times to protect the vine; it is, in
fact, a preventive rather than a curative method.

Ophiobolus (jraminis, Sacc. (disease of the stem of wheat). — This,
disease may be avoided by burying in the soil 80 kilogrammes of green
vitriol per hectare (70-4 lb. per acre) (McAlpine).

DoiJiichiza jjopidea. — To prevent infection through wounds it is
sufficient to coat them with a solution of 10 per cent of green vitriol
and to cover them with a mastic.

Use of Green Vitriol against Insects. — Anthonomus pomorum

POTASSIUM FEEEOCYANIDE. 187

(apple blossom weevil). — Mohr advises to kill this insect in winter when
it seeks refuge in the inequalities of the bark, to scrape the trunk, collect
and burn the bark, and coat the whole trunk afterwards with a pasty
mixture of 20 lb. of green vitriol, 10 gallons of water and a suflficiency
of potters' clay. Spraying with a 20 per cent solution of green
vitriol would appear to be as efficacious as liming the trees or Balbiani's
coating.

Cochi/lis amhignella, Hubn. (tortrix of the vine). — The grubs resist
somewhat concentrated solutions of green vitriol. A 2-3 per cent
solution has no effect (Mohr), nor a 10 per cent solution (Dufour).
Martini diminished the Coehylis 27 per cent by winter decortication
followed by coating with a 45 per cent solution of green vitriol and
1 per cent of phosphoric acid.

Tipula pratensis, L. (meadow gnat). — The larvee of the tipula, which
cause ravages in meadows and lawns, are killed by gi-een vitriol : it is,
however, preferable to till the meadow, spread green vitriol, and sow
again.

Aphides. — Naked plant lice are sensitive to the action of green vitriol.
A 1 per cent solution kills them (Mohr). On fruit trees injected with
green vitriol and conveying this product in their sap, cochineals,
such as Diaspis fallax and Mytilaspis piomomvi, which live on this
sap, gradually disappear. Mohr found that the larvae of the woolly
aphis Schizonenra lanigera, Hausmann, are killed by an emulsion of
gi-een vitriol 1 lb., amyl alcohol 5 lb., water 10 gallons. The action
of green vitriol on phylloxera is nil.

Nematodes. — Green vitriol applied in large doses as manure on in-
fested fields kills nematodes (Zimmermann).

Earth-worms (Lombricus) are also destroyed by green vitriol, which
can be mixed with the manure.

S7iails and Slugs. — Slugs are very sensitive to green vitriol. To
destroy them sow a mixture of green vitriol and sand in the evening,
preferably in wet weather, on the soil frequented by snails and slugs.
Eouzaud advises to protect vine buds from slugs to coat the stem
with a solution of green vitriol, which penetrating through the mucous
of the slugs kills them if they climb on a stem treated in that way.

69. Ferric Sulphate, Fe^,(S0^)3. — Preparation. — By heating 100
parts of green vitriol, 100 parts of water, and 20 parts of sulphuric
acid, then adding nitric acid until no more brown fumes appear. The
bi'own solution on evaporation yields a yellow salt.

Properties. — Soluble in water and endowed with the disinfectant
properties of green vitriol.

Use. — Griffiths particularlj' recommends it against parasitic fungi.
As a tonic he regards it as superior to gi'een vitriol because it is more
directly assimilable by the roots.

70. Ferrocyanide of Potassium (yellow prussiate). — Prepara=
tion. — By calcining blood in closed vessels with potassium carbonate
potassium cyanide is formed and removed by lixiviating the mass with
boiling water. The lye is then boiled with iron in contact with air ;
there is absorption of oxygen and yellow prussiate is formed. The
crystallized salt is obtained by concentration and evaporation.

188 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Use. — Mouillefert tried yellow prussiate on Phylloxera vastatrix.
He watered a phylloxera-infested vine in a pot containing 3 litres of
earth with a 2 per cent solution. At that strength yellow prussiate
killed all the phylloxera. Mouillefert renewed his trials on the large
scale. He laid down 100 grammes (3^ oz.) of prussiate around each
stock and afterwards applied water. The results confirmed the poison-
ous action of this substance. Unfortunately, it is not without effect
on the plants and it temporarily injures the vine. Knop formerly
showed that if yellow^ prussiate was capable of imparting to the plant
the iron which it required, it was, on the other hand, often injurious to
it. He made the curious observation that the prussiate added in small
■dose to no matter what nutritive liquid stopped growth forthwith of
the plants in no matter what stage of growth. Without dying the
plant appeared to stop growth ; it subsisted but showed no growth.
It follows from the experiments of Bahadur (?) that yellow prussiate
is a very feeble poison to young plants and absolutely harmless to
fungi when used in the dark. It is quite otherwise in the light. It
decomposes with formation of prussic acid which renders it poisonous.

71. Prussian Blue (ferric feiTOcyanide). — Discovered at Berlin,
1710. — Preparation. — By acting on yellow prussiate with a ferric salt.

Properties. — Prussian blue is a precipitate insoluble in water but
soluble in oxalic acid. Weak acids do not decompose it, but strong
acids and caustic alkalies destroy it.

Use. — Prussian blue in paste was used in 1894 by Galloway and
Fairchild. The former tried it against rust of cereals, the second to
prevent Entoviosporiiivi maculahim, Lev. (spots of the leaves of the
pear-tree). Although the adherence of this paste was superior to that
•of bouille bordelaise, Galloway found that Prussian blue possessed no
anticryptogamic property owing to its absolute insolubility in atmos-
pheric agents. In spite of a large number of sprayings the fields of
oats and summer wheat were invaded by rust. Fairchild, however,
remarked a certain action on the pear-trees treated, although much
weaker than modified eau celeste.

72. Borate of Iron, FeB^O^. — Preparation. — By adding borax
to a ferrous salt. A grey precipitate is formed which turns yellow
rapidly by oxidation. Fairchild prepares a borate of iron paste by
■dissolving 6 lb. of dry green vitriol in 50 gallons of water and adding a
solution of 24 lb. of borax in 50 gallons of water. Fairchild tried this
paste against Entomosporum maculatum (spots of the leaf of the pear)
and against Phyllosticta sphceropsidea, E. and E. (spots of the leaf of
the chestnut). This paste behaved like all pastes containing insoluble
iron, that is to say, without action on the spores of fungi they are
•somewhat injurious to vegetation. Galloway's experiments to combat
rust of oats and summer wheat with this bouillie also gave negative
results.

CHAPTEE XI.

POTASSIUM BICHROMATE (BICHEOME)- CHROME ALUM— POTASSIUM
PERMANGANATE— MANGANESE SULPHATE— NICKEL SULPHATE-
COBALT SULPHATE.

73. Potassium Bichromate, KoCi\,0; ; 74. Chrome Alum,

K2S04Cro(SO^).^24:HoO. — Preparation. — Bichromate of potash is ob-
tained commercially b}^ calcining chrome ore on the sole of a rever-
beratory furnace with half its weight of nitrate of potash. The mass,
is then lixiviated with water and acetic acid added to saturation.
Whilst precipitating silica and alumina this acid converts the neutral
chromate into bichromate. After filtration the liquor yields, when
concentrated, orange crystals of bichromate of potash. Chrome alum
is obtained by treating a solution of 150 lb. of " bichrome " with 250
lb. of sulphuric acid and 60 lb. of alcohol.

Properties. — Crystals of " bichrome " are permanent in the air.
They dissolve in ten times their weight of water at 29' C. Chromates
are very poisonous ; in small doses they produce by a specific slow
poisoning caries of the bones of the nose.

Action of Chrome Salts on Plants. — Chrome salts, chiefly
chromates, are poisonous to plants. H. Coupin in 1898 determined
the toxicity of the different chrome salts by adding them to a nutritive
solution ; he found that the following quantities disturbed the growth
of cereals : —

TABLE XXIV. — Showing the Toxis Dose of Different Chrome Salts in a
Nutritive Solution (Coupin).

Per Cent.

Chrome alum 1-142

Chromium sulphate .

0-5

Chromic acid

0-00595

Potassium chromate .

00625

Bichromate of potash

00312.5

Sodium chromate

0-012O

Bichromate of soda .

0-0064

Ammonium chromate

0-0625

Bichromate of ammonium

0-025

Action of Chromium Salts on Parasitic Fungi. — It follows from
Hitchcock and Carleton's experiments that whilst a 1 per cent solution
of chrome alum has no action on the uredospores of the Puccinia
coroncUa, Corda, a 1 per cent solution of bichromate of potash lowers
considerably the germinating capacity of these spores after twenty-
four hours' immersion and destroys them by more prolonged contact.
A 01 per cent solution his no action on the uredospores, but if the

(189)

190 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

contact be prolonged after nineteen hours the germination of the spores
becomes more difficult.

Use. — Bust. — As a preventive against rust, Galloway tried bi-
chromate of potash. The seeds were immersed for twenty-four hours in
a 5 per cent solution of bichrome and the ground sown watered with
a solution of the same strength. The use of the bichrome enabled him
to free the field from rust, but the yield was inferior to that on the check
plot infested with rust. Bichrome solutions act in as poisonous a
manner on the seeds as on the spores which contaminate them, and it
follows after this disinfection that the seeds do not spring up except
in small proportion. The watering of the sown ground is likewise
very prejudicial to the sprouting of the grain.

Stinking Smut (bunt). — Kellermann and Swingle came to the same
conclusions as Galloway as to the action of bichrome on the spores of
fungi and on the grain of cereals. Although an immersion cf twenty
hours in a 5 per cent bichrome solution kills the spores of Tilletia
caries, Tub, the treatment cannot be utilized as the grains suffer too
much.

Peronosj^ora viticola, De By. (mildew of the vine). — Kaserer tried as
a substitute for bouUlie bordelaise : (1) a mixture of 1 per cent of
bichromate and lime, (2) a mixture of 1 per cent of chrome alum and
lime; these two bouillies only gave absolutely negative results, but
whilst the bichromate of lime greatly damaged the leaves the hydrated
oxide of chromium did not injure them.

Conchylis ambignella, Hub. (cochylis). — Dufour tried against the
caterpillar of this butterfly a 3 per cent solution of bichrome, but he
found that it in no way disturbed the caterpillars, whilst it spoiled the
grapes.

75. Permanganate of Potash, KMnO^. — Preparation. — By
heating in an iron crucible a mixture of 50 parts of manganese dioxide
with 50 parts of potassium chlorate and 60 parts of potash dissolved in
the smallest quantity of water. This mixture is gradually heated to
dull redness, then cooled and extracted with boiling water. A purple
liquid is thus obtained which crystallizes on evaporation in blackish
violet needles with metallic lustre.

Properties. — Potassium permanganate dissolves in 15-16 parts of
cold water. It is a powerful oxidizing agent decomposing organic
matter in the cold. Owing to this property it acts as an energetic and
rapid disinfectant (Condy's fluid) ; its action is instantaneous, especially
in the presence of an acid. Weak permanganate solutions do not
keep in open vessels, and it is best to use these anticryptogamic solu-
tions immediately after their preparation.

Action on Fungi. — The spores of fungi resist the action of this
oxidizing agent better than that of poisonous salts. Hitchcock and
Carleton found that the uredospores of the Puccinia graminis, Pers.
(linear rust) can germinate in a 1 per cent solution of permanganate
of potash. Arieti found that the dose required for the disinfection of
seed-corn was so strong that it killed the grain as well as the adherent
spores. It is otherwise with the mycelium of fungi. The tender
filaments of the mycelium are easily destroyed by permanganate solu-

POTASSIUM PERMANGANATE. 191

tions ; the effect is produced instantaneously. But as permanganate
solutions cannot penetrate into the organs of plants to destroy the
mycelium which vegetates in and between the cells, permanganate finds
no application except to destroy fungi, the mycelium of which live
on the surface of the plant, that is to say Erysiphe and Cajmodium.

Action on Insects. — The action of permanganate is weak and
sometimes nil. Perroncito immersed the eggs of Bombyx Mori, L. (silk-
worm) in a 1 per cent solution. After twelve hours the action was nil ;
only after twenty-four hours' immersion were the greater part of the
eggs destroyed. Trials made in 1872 (Samal process) to destroy the
phylloxera of the vine by watering the stocks with a 0-06 per cent
solution failed because the permanganate was decomposed before
reaching the roots infested with this aphis. However, Stengele recom-
mends a 1*25 per cent solution of permanganate to kill infallibly the
woolly aphis.

Use. — Erysiphe communis, Wal. (mildew of the pea). — Douaire
simultaneously tried sulphur and permanganate of potash against this
parasitic fungi, the mycelium of which lives on the surface of the
diseased plant, and he obtained the best result with the latter. Used
at the rate of 1 lb. in 100 gallons of water permanganate completely
stopped the invasion of this fungus. A few days after this treatment
the less-attacked leaves had become green again, whilst those which
were greatly attacked bore black spots in the places where the epi-
dermic cells had suffered from the fungus. To obtain a definite result
spraying must be done carefully so that both surfaces of the leaves are
moistened. This treatment only produces a curative effect, never a
preventive one. It can in no way prevent a fresh invasion by spores
coming from elsewhere.

Oidium Tuckeri, Berk, (oidium of the vine). — Of all the fungi the
mycelium of which live on the exterior of the diseased plant the most
formidable is the oidium of the vine, which, if very resistant to copper
salts, may be easily contended against by sulphur and soluble sulphides.
Permanganate of potash has also been recommended to kill this para-
site. Guocdenovic tried a 0"1 per cent solution of permanganate
which proved entii-ely satisfactory. Kulisch repeated these experi-
ments to compai'e the results with sulphur. He used solutions made
at the rate of 1^-2^ lb. per 100 gallons of water. He found perman-
ganate produced good results, but the good effect was purely local, and
to obtain a complete result it was necessary to reach the whole surface
of the plant by spraying. On the other hand, sulphur, which acts by
the vapours which it disengages and which penetrate everywhere, pro-
duces complete disinfection without it being necessary to cover the
whole surface of the vine with sulphur. It has been seen that it is
sufficient when the temperature and the atmospheric conditions are
favourable to deposit the sulphur at the foot of the stocks to destroy
the oidium completely. The advantage of permanganate of potash lies
in the fact that it can be mixed with cupric bouillies without losing
its properties. Added to bouillie bordelaise one can contend in a single
treatment against oidium, mildew, and black rot, which is a great
economy of time.

192 IXSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Peronospora vitlcola, De By. (mildew of the vine). — Ch. Truchot
recommends a permanganate solution of 0-125 per cent against mildew.
Tried in the Canton of Vaud in Switzerland it sometimes gave excel-
lent, sometimes negative results. It is otherwise with a mixture of
bouillie bordelaise and permanganate of potash. Guocdeuovic made
up bouillies containing 0'75 per cent, 0*5 per cent, 0-25 per cent of
blue vitriol and 0*1 per cent of permanganate of potash. Compared
against ordinarj^ bouillie bordelaise these permanganate bouillies gave
better results even when they only contained 025 per cent of blue
vitriol and O'l per cent of permanganate of potash. This mixture
whilst giving excellent results effects great saving in copper. The
permanganate! bouillie bordelaise behaves both like bouillie bordelaise
and as blue vitriol, that is to say, it possesses, along with the reserve
of copper to prevent the invasion of the mildew and prolong the action
of the bouillie remaining on the leaves, a very active substance having-
an immediate deadly action on the exterior organs of these fungi, the
conidiophores. This bouillie gives good results when it is a case of
arresting a sudden invasion during a moist warm period of summer.
However, permanganate alone does not suffice to contend against this
disease, for it has only a curative action and is entirely deprived of pre-
servative effect. It is therefore necessary to multiply the treatments an
infinite number of times with permanganate alone to get a result ana-
logous to that obtained with cupric bouillies or permanganated cupric
bouillies.

Disinfection of Trees. — It has been recommended to coat fruit
trees in the spring when the buds are barely formed with an 0*125
per cent solution ; it is even recommended to spray the whole trees
with this solution after flowering. The results were very satisfactory.

Botrytis Douglasii, V. Tub. (conifer disease). — The rot of conifers-
produced by Botrytis cinerea, Pers., has been combated by Van Bier-
vliet by making sprayings with a bouillie consisting of —

Copper sulphate ....... 700 oz.

Carbonate of copper ...... 1360 „

Permanganate of potash . . . . . 85 „

Soft soap 225 .,

Rain water 500 gallons.

Nematoides. — Humphrey got excellent laboratory results against
the nematoides of the violet by frequently spraying with a 0*05 per
cent solution. The experiments on the large scale, however, did not
succeed.

76. Manganese Sulphate, MnS0^5H,0. — Preparation. — By
dissolving manganese in sulphuric acid.

Properties. — The same as green vitriol.

Action of Manganese Salts on Plants. — The action of manganese
salts on plants has been examined chiefly in Japan. The experiments of
Loew and Honda to determine the action of sulphate of manganese on
the growth of Cryptoviaria japonica have shown that manganese salts,
possess like copper and other analogous salts the property of stimulat-
ing the growth of the plant and in that way increasing the yield of the
crop. The yield in their case was 64G 7 grammes against 316'9

NICKEL SULPHATE. 193

grammes for the check plants. Aso found manganese chloride, used
as a manure in the cultivation of rice, increased the yield 42 per cent.
Nagao pointed out this property for sulphate of manganese, and finally
M. Fukutome observed that a mixture with manganese sulphate had a
superior action on plants to that of these salts used separately. Al-
though manganese does not form according to Gossel's researches a
plant food, in general the manganese content of cultivated plants is
barely appreciable, yet trees, especially pines, contain appieciable
quantities; it hastens vegetation and stimulates growth.

Use. — Peronospora viticola, De By. (mildew of the vine). — Sbrozzi
used this salt to combat the mildew of the vine, but the results were
negative. Kaserer did not succeed better with 0-5 per cent solutions
of borate of manganese.

77. Nickel Sulphate, NiSO^THp.— Preparation.— Nickel sul-
phate is formed by dissolving nickel, its hydrated oxide or its carbonate,
in dilute sulphuric acid of 15" B. It crystallizes from its solutions in
the hydrated state with 7 molecules of water.

Properties. — Crystallized nickel sulphate is green ; it dissolves
readily in water. Alkalies yield with solutions of nickel sulphate an
apple-green precipitate of hydrated oxide of nickel insoluble in water,
soluble in ammonia and in carbonate of ammonia. The ammoniacal
solution of protoxide of nickel dissolves silk (Schlossberger). There is
thus great analogy between the physical and chemical properties of
nickel and copper sulphates as between nickel hydrate and copper
hydrate. A nickel hydrate bouillie behaves as to solubility in atmo-
spheric agents and its adherence like bouillie bcrdelaise.

Action of Nickel Sulphate on Plants. — Nickel sulphate, like
copper sulphate and other poisonous plants, possesses the property of
stimulating the vitality of these plants if absorbed by them in minirnum
proportion. Eichards treated different fungi and algae growing in
nutritive solutions with small quantities of nickel, copi^er, zinc, and
cobalt sulphates, sodium fluoride, lithium nitrate, sodium arseniate.
The dose required to stimulate algaB is much less than for fungi. By
increasing the dose there is an immediate poisonous action on plants ;
2^ milligrammes of nickelous oxide used as nickel sulphate in 1 litre
of water (2| parts in 1,000,000) stop the growth of maize and haricot
(Haselhoti). Nickel sulphate behaves like blue vitriol in a nutritive
solution used to combat the cryptogamic diseases of plants ; it, owing
to the infinitesimal quantities absorbed by plants, imparts more vigour,
and that in itself gives more resistance to the plant. However, the
stimulating effect of nickel sulphate is not so decided as that of copper
salts (Aso, Nakamura, and Suzuki).

Action of Nickel Sulphate on Parasitic Fungi. — Nickel sul-
j)hate has a very toxic action on parasitic fungi. It much resembles-
that of blue vitriol, to which it is superior or inferior according to the
parasite treated. A 1 per cent solution of nickel sulphate does not
kill the uredospores of Pucclnia coronata, Cord.

Use. — Peronospora riticola, De By. (mildew of the vine). — Gallo-
way tried, in 1889, nickel sulphate and nickel hydrate against blue
vitriol and cupric bouillie. He concluded that its sporacidic and pre-

13

194 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

servative action is inferior to that of cupric derivatives. Sbrozzi'g
trials in 1900 confirmed this conclusion. Guocdenovic in 1900 made
comparative experiments with 0-25, 0'5, 0'75 per cent copper bouillies
and with nickel hydrate bouillies, made like bouillie bordelaise with
0"25, 0*5, and 1 per cent of nickel sulphate. The action of these
bouillies was identical. The 0'25 per cent nickel hydrate bouillie was
still active, and more effective than the bouillie bordelaise with 0"25
per cent of blue vitriol. He concluded that nickel bouillie could
perfectly well replace bouillie bordelaise against this fungi.

Botrytis cinerea, Pers. (grey rot of the vine). — Viala and Gouirand
made interesting researches on the comparative action of nickel and
copper sulphates on this redoubtable fungus. According to the experi-
ments copper salts have little action on the germination of the Botrytis.
Whilst the spores of Peronospora vlticola are killed in a solution of
3 parts in 10,000,000 of blue vitriol, it takes a 5 per cent dose of blue
vitriol to prevent the germination of Botrytis cinerea. It is not so
with nickel sulphate which is 40 times stronger than blue vitriol.
In a solution of 2 parts per 10,000 the spores are almost entirely
prevented from germinating. Nickel carbonate has shown the same
superiority as compared against the Burgundy bouillie, for whilst it
takes a 7'5 per cent cupric bouillie to prevent all spores from germin-
ating in sixteen hours, a 1 per cent nickel bouillie has the same
effect. The results, repeatedly verified, have always been the same.
Experiments on the large scale against grey rot do not appear to have
been made as a sequel to the laboratory experiments of Viala and
Gouirand. Is it because aluminium sulphate, much cheaper, produces
equally good results ?

78. Cobalt Sulphate, CoS0^7HoO. — It was purely of scientific in-
terest to investigate the action of cobalt salts on plants and parasitic
fungi, for these salts are too dear to be used on the large scale. Cobalt
sulphate was tried comparatively against nickel sulphate and blue
vitriol by Eichards. Its action on plants was found to be analogous
to that of the two latter salts, stimulating in small dose, poisonous
in larger doses. The experiments of Aso, Nakamura, and Suzuki,
on Allium, Brassira chinensis, Hordeuvi, and Pjs»m, enable us to con-
-clude that its stimulating action is not very decided.

CHAPTER XII.

RED LEAD— LEAD ARSENIATE— LEAD ARSENITE— LEAD CARBONATE
(WHITE LEAD) — LEAD ACETATE (SUGAR OF LEAD) — SILVER
NITRITE (LUNAR CAUSTIC)— SILVER CHLORIDE.

79. Red Lead, PbyO^. — Preparation.- — By heating massicot PbO
in special furnaces to •io0°-500' C.

Properties. — Red lead is a brilliant red powder, insoluble in
water.

Use. — Seed beds may be completely preserved against the attacks
of sparrows and other granivorous birds as follows : 20 lb. of seed are
mixed with 1 lb. of red lead and stirred, so that the seeds may be uni-
formly red. The seed is sown as usual and the birds shun the land
where they have been sown. Von Tubeuf recommends red lead
particularly to preserve pine and spruce fir seeds.

80. Arseniate of Lead, Pb^AsoO^. — Preparation. — By acting on
a solution of 10 lb. of arseniate of soda with 18 lb. of lead acetate, or
15 lb. of lead nitrate, dissolved in water. To prepare the bouillie the
liquor is made up with water to 250-376 gallons. Marlatt's bouillie
contains 10-24 lb. of arseniate of lead and 50 lb. of glycose in 1000
gallons of water.

Properties. — Lead arseniate is one of the most insoluble of
arseniates in water. It forms in the bouillie a finely divided precipitate
which remains well in suspension, which is not the case with many of
the arsenite greens of a density of 3 and the consistency of which is
very granular.

Action on Plants. — Owing to its insolubility it is perfectly harm-
less to the plant, and that is one of the great advantages of this product,
for all arseniates are more or less soluble in water, and thus more or
less injurious to plants. Woods' experiments on potatoes have shown
the harmlessness of three sprayings annually and spreading 5"5 lb.
of arseniate of lead altogether (?per hectare, say 4"4 lb. per acre).
Besides, it was impossible to find even traces of arsenic in the tubers.
A bouillie containing 0*5-1 '0 per cent of arseniate of lead never
scorches the leaves, so that bouillies containing a large proportion of
poison may be used, when the insects stand strong doses of arsenic
and re=iist all arsenite of copper bouillies.

Action on Insects. — Its poisonous action on insects is not in equal
doses as rapid as that of copper arsenite. Arseniate of lead is a
violent poison for man. Used without precaution it is as dangerous as
lead salts and arsenites. It chiefly affects the sight. Some cases
have been quoted in America where this bouillie is in constant use.

Use. — Lead-arseniate bouillies cannot replace copper-arsenite and

(195)

196 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

lime-arsenite bouillies in every case. Its greater adherence, increased
by the addition of glucose, is such that it remains fixed on the organs
of the sprayed plants during the whole season. This adherence,
therefore, excludes it in all cases where the plants or the fruits treated
are intended for food. But, wherever that is not the case, lead
arsenite may replace copper arsenite. The bouillies are best made on
the spot ; 0*2 per cent suffices in most cases. But some parasites
require 0'7 per cent, and even 1 per cent. It is calculated that it
takes three to four times more of this bouillie to obtain the same result
as from that with an emerald-green basis. But the lead-arseniate
bouillie, consisting of a flaky precipitate, enables the poison to be more
uniformly distributed, and by its white colour shows the spots touched.
A preparation of arseniate of lead on the market called "Disparin,"
contains lead oxide 49, arsenic acid 16, tar 4, water 31 = 100. Lead
arseniate is especially used against a butterfly whose caterpillar has
become quite a plague —

Ocneria dispar, Sch., or Lvparis dispar, L. [Bomhyx dispar, gypsy
moth). — Spraying with cupro-arsenical bouillies is without efl'ect as
the caterpillars are capable of absorbing strong doses of copper arsenite
without dying. By the use of a 1 per cent lead-arseniate bouillie very
satisfactory results have been got in America. To destroy the cater-
pillars the spraying must be done at the time they are hatched, for the
young caterpillars are more sensitive than the adults. It is possible to
destroy 90 per cent of the young caterpillars and only 60-70 per cent
of the adults. This process, therefore, appears to give better results
than the gathering of the nests of eggs in winter.

Leptmotarsa decemlineata (Colorado beetle). — Woods recommends
to destro)^ insects injurious to potatoes, such as the Colorado bettle,
altises, etc., a bouillie consisting of 0-24 per cent of lead arseniate. If
it be desired to combat cryptogamic parasites simultaneously there is
added to bouillie bordelaise 24 lb. of arseniate of lead per 1000
gallons. Lead-arseniate bouillie is in general use in America. The
following is, however, a list of the insects against which it has been
particularly recommended : (1) Galeruca luteola, Sch., on the elm ;
(2) Galeruca anthomelcBna, Schr., on the elm ; (3) Crioceris asparagi,
L., asparagus beetle ; (4) llliopohdta Vacciniana, Pack., butterfly in-
jurious to the cowberry (whortleberry, Kirkland) ; (5) Orthocraspeda
trima, Moore, butterfly injurious to the cacao tree (Zehntner) ; (6)
Plutella, Margantia, Mamestra, aphides, insects injurious to cabbages
(Garman) ; (7) Ennomos suhsignaria, phalena of the apple (Garman) ;
(8) Carj)ocapsa Pomonella, codlin moth. Trials to destroy this codlin
moth were made with a bouillie bordelaise containing 6-12 lb. of lead
arseniate or of disparin per 1000 gallons. Gillete and Garman by its
use reduced tlie percentage of wormy apples from 50 per cent (on the
check trees) to 4 per cent. (9) Emphroctis chrysorrhca. — Weed ad-
vises to cut the nests in the spring and spray with lead arseniate on
the young caterpillars; (10) GrajjholitJia hotrana (tinea of the vine).
— Slingerland recommends three sprayings with a 1 per cent bouillie
of lead arseniate, the first a little before flowering, the second after
flowering, and the third when the grapes are the size of a pea.

SILVER NITRATE (LUNAR CAUSTIC). 197

8i. Lead Arsenite, PbAs.O,,.— Preparation.— Sodium arsenite
6 oz., lead acetate 32 oz. ; dissolve separately in water, mix with solu-
tions, and make up the bulk to 62^ gallons. It may be bought under
the name of arsenoid rouge (red arsenoid).

Properties. — Preciphated arsenite of lead is finer than arseniate of
lead, but it is a little more soluble in water than the latter. Lead
arseniate is therefore preferred against plant diseases.

82. Lead Carbonate. — Passerini tried lead carbonate against Per-
onospora riticola, De Bv., but he obtained no useful result.

83. Lead Acetate, Pb(C.H30,)-, aH.O.— Preparation.— By
dissolving lead in acetic acid.

Properties. — Soluble in water, with a saccharine taste. Very
poisonous, like all lead salts, and absorbed in small regular doses it
causes the complaint known as painter's colic.

Action of Lead Salts on Plants. — Lead acetate acts on
plants as on our organism. Placed in strong doses in contact with
the roots of plants it kills them, yet young plants of peas, maize,
and oats, cultivated in nutritive solutions, are not killed in four days
after receiving 1 per cent of lead as lead nitrate (Nobbe, Bassler, Will).
By slow absorption in small doses it eventually produces a paralysis
of growth, an arrest of the normal growth, and a special nauisme (?).

Action of Lead Acetate on Parasitic Fungi.— Hitchcock and
Carleton found that the germinative power of the uredospores of
Puccinia coronata, Corda, was reduced by immersion in a 1 per cent
solution of lead acetate.

Vse.—TiUetia caries, Tul. (bunt).— A commercial product with an
acetate of lead basis, sold as " Germinateur guarante," was recom-
mended for the disinfection of seed-corn. Schribaux, the director
of seed control of the Agronomical Institute of Paris, examined this
product comparatively with blue vitriol, and found it 100 times less
active than the latter on the spores of Tilletia caries, Tul. Lead
acetate cannot therefore replace blue vitriol in the disinfection of seed-
corn.

Peronospora viticola, De By. (mildew of the vine).— Kaserer made
a series of experiments against this disease, spraying with the follow-
ing bouillies : —

Mixture of 100 grammes of lead acetate and milk of lime.
250
500
,, 500 ,, of lead nitrate ,,

The lead hydrate which is formed by lead acetate or nitrate with milk
of lime appears to have, owing to its solubility in pure water, a rather
decided action on the spores of Peronospora viticola. Owing to the
rapid conversion of lead hydrate into insoluble carbonate of lead, the
action of the bouillie is not so lasting as that of copper bouillies.
Besides the adherence of the deposit is less than that of bouillie
bord-laise. The vines treated showed no signs of poisoning.

84. Nitrate of Silver.— Preparation.— By treating pure silver
with nitric acid the liquor forms colourless lamellae of silver nitrate on
cooling.

198 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Properties. — Silver nitrate is soluble in half its weight of water
and in the tenth of its weight of boiling water ; it dissolves also in 10
parts of cold alcohol and 4 parts of boiling alcohol. Fused and run
into sticks silver nitrate yields the infernal stone used in medicine.
Silver nitrate decomposes readily ; it is slowly reduced by light and
organic matter to silver oxide. In medicine it is used to cauterize
wounds and remove false membranes (proud flesh) ; internally it is
used in doses of 1-4 centigrammes ; in greater doses it is poisonous.
It is an antiphlogistic and sedative. Silver nitrate combines with
albumen, forthwith forming a precipitate of an albumen salt soluble
in excess of albumen and in solutions of common salt. Nitrate of silver,
therefore, behaves towards albumen like many powerful antiseptics.
Its powerful action on spores and microbes results from these pro-
perties and its action on the living plasma. In very dilute solution
it interferes with the vitality of the plasma which on contact therewith
blackens owing to the metallic silver formed.

Action on Plants. — It suffices to water plants with a very dilute
solution of nitrate of silver to kill them infallibly. To prevent wheat
from germinating it suffices to steep it in a bath containing 0*029
gramme of nitrate of silver per litre, that is, 29 lb. in 10,000 gallons.

Action on Fungi. — Nitrate of silver is as injurious to fungi as to
plants. It only requires an infinitesimal dose of this substance, which
analysis cannot detect, to prevent the spores of the saprophytic fungus,
Aspergillus niger, from germinating (Eaulin).

Use. — Silver nitrate is not used as an anticryptogamic in the
struggle against the diseases of plants, its action on the latter being
too deadly. A process recommended in 1872 by Petit for the destruc-
tion of the phylloxera gave no result.

85. Silver Chloride, AgCl. — Preparation. — By precipitating a
solution of silver nitrate by a solution of common salt, a white curdy
precipitate forms, soluble in ammonia and hyposulphite of soda.

Properties. — Silver chloride is insoluble in water. Its properties
are the same as those of the nitrate, that is to say, it decomposes
readily in light and in presence of organic substances.

Use. — Peronospora viticola, De By. (mildew of the vine). — Pauli
advised a mixture of silver chloride and hyposulphite of soda tinted
with eosin, and sold as " Puknos," against the cryptogamic diseases of the
vine, tomatoes, potatoes, rose-trees, and fruit-trees. The good anti-
cryptogamic effects produced in general have been observed in a large
numbei- of vineyards treated. Unfortunately the use of this solution
was followed, especially after gi'eat heat, by serious burning of the
leaves. Its two components being too toxic for plants the use of
" Puknos " was abandoned.

CHAPTEE XIII.

COPPEK SULPHIDE— COPPEK NITRATE— COPPER CHLORIDE— COPPER
SULPHITE— COPPER SULPHATE (BLUE VITRIOL).

86. Copper Sulphide, CuS. — Preparation. — (1) By passing a cur-
rent of sulphuretted hydrogen into a solution of a copper salt. The
black precipitate formed is filtered and washed with a solution of sul-
phuretted hydrogen. (2) By double decomposition of sulphate of copper
by the sulphide of an alkali or alkaline earth.

Properties. — Copper sulphide is an amorphous black precipitate,
absolutely insoluble in water. In moist air it oxidizes and forms
sulphite and sulphate of copper. By heat it decomposes into basic
copper sulphide and sulphur.

Use. — Copper sulphide has heen recommended against oidium as
well as mildew, that is to say, to unite in a simple treatment both
sulphur and bouillie bordelaise. Copper sulphide, containing the
necessary elements to fight these two parasites, it was thought might
produce the desired effect. It was not so, however, and Viala's ex-
periments at the Montpelier school showed that copper sulphide
neither protects vines from mildew nor kills the oidium. Numerous
observers hold the same opinion as Viala and condemn mixtures
which form copper sulphide. In fact, the copper is so insoluble in
this sulphide derivative that this preparation no longer cedes to dew
or rain the indispensable amount of copper to prevent the germination
of the spores which have been transported by the wind, and the sulphur
in the sulphide no longer possesses the properties of sulphur. It is not
volatile, and cannot consequently act by its vapours. However,
copper sulphide may oxidize in the air and thus cede to the water on
the leaves a little soluble copper as copper sulphate. This, in fact,
occurs in moist countries, and it is one of the reasons why certain
experimenters found a protection in it against mildew equal to that of
bouillies. The special bouillies recommended by Fairchild, and after-
wards by Eabate, may perfectly combat oidium, but they have only an
imperfect action against mildew. Consisting of a mixture of 4 lb. of
copper sulphate and of 4 lb. of sodium polysulphide (liver of sulphur) in
100 gallons of water, in the first instance, and a mixture of copper
sulphate and lime sulphide in the second, they contain, along with
precipitated copper sulphide, sulphides, or polysulphides of sodium
or calcium, as well as precipitated sulphur, which have a well-deter-
mined action on oidium.

Against Entomosporiummaculatum (spots of the leaves of the pear)
Fairchild did not find h"s bouillie superior to ordinary copper bouillies.

(19U)

200 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Galloway, however, found it act better against rust of oats and summer
wheat. Plots treated on 6, 16, and 20 June, then on 5 July, were not
diseased, and yielded 104^ units of sound grain against 8^ units in the
untreated plots, the plants of which were diseased.

If sulphur be mixed with fat lime in the proportion of fat lime
260 lb., precipitated sulphur 260 lb., water 7 gallons, and the pro-
duct mixed with a copper salt in the following proportion, above mix-
ture 4 lb., copper sulphate 2 lb., water 10 gallons (Guillon's formula),
a bouillie is obtained which, used immediately after its preparation,
enables oidium and peronospora to be contended against simultane-
ously, because sulphur only acts very slowly on coj)per hydrate to
form copper sulphide. It is otherwise if a solution of copper sulphate
is mixed with soluble sulphides, or even if the sulphur is added to
alkaline bouillie ; these bouillies are blackened instantly by the copper
sulphide formed and are now merely copper sulphide bouillies, less
adherent and less active than bouillie bordelaise.

87. Copper Nitrate, Cu(N0y).,3H,0.— Preparation.— By dis-
solving copper in dilute nitric acid and crystallizing the solution.

Properties. — -Soluble in water with the same anticryptogamic pro-
perties as copper sulphate.

Use. — Hitchcock and Carleton tried the effect of a 1 per cent solu-
tion on the spores of different fungi. At that strength the spores of
rust (Puccinia coronata) were destroyed. Copper nitrate is regarded
as one of the best means of destroying weeds, and is used on the large
scale to destroy charlock.

88. Copper Chloride, CuCl.,2H.,0. — Preparation. — By dissolv-
ing copper oxide in hydrochloric acid, or copper in aqua regia, and
evaporating the solutions. Copjoer chloride bouillies are prepared by
mixing 249 lb. of copper sulphate and 219 lb. of calcium chloride ;
sulphate of lime is precipitated and copper chloride goes into solution.

Properties. — Copper chloride is soluble in water. It behaves like
copper sulphate as regards its corrosive action on leaves and its anti-
cryjDtogamic effects. Its molecular weight being 170, that of copper
sulphate 249, and the action of copper salts being in inverse ratio to their
molecular weight, the chloride will, in doses of equal weight, be moi^e
active, and should be used in smaller doses than copper sulphate.
Galloway has, however, remarked that dilute solutions of copper
chloride do not attack the leaves of plants like those of copper sulphate ;
it is necessary to attribute this difference to the different nature of the
hydrochloric acid and sulphuric acid which form these two salts, the
first is volatile, the second is not so.

Galloway used against the black rot of the vine a mixture, consist-
ing of 7^ oz. of copper sulphate, 4 oz. of calcium chloride, in 624
gallons of water. This bouillie much diminished the black rot. The
vines sprayed six times showed 98-1 per cent of healthy grapes against
41-61 on the untreated stocks. On the other hand, being very dilute
it does not attack the leaves at all. A 1 per cent solution prevents
the germination of the uredospores of Puccinia coronata, Corda (rust
of oats), (Hitchcock and Carleton). Along with pure solutions of
cop])er'chloride thoie are used in America, with little success it is true,

COPPER SULPHATE (BLUE VITRIOL). 201

solutions containing oxychloride of copper obtained by precipitating
copper sulphate with bleaching powder. These bouillies, studied by
Fairchild, consist of blue vitriol 2 lb., chloride of lime 3 lb., in 100
gallons of water, or of blue vitrol 2 lb., chloride of licoe 4 lb., in 100
gallons of water. These bouillies, which like true Brunswick green,
CuCloSCuO, 4H.,0, contain a greater or less excess of chloride of lime,
produce very disastrous effects on the leaves. Compared with other
bouillies they are less adherent and less active against cryptogamic
diseases. Tried against Entomosporium 7naculatum, Lev. (spots of
the leaves of the pear) they do not prevent the disease, and seriously
damage the leaves.

89. Copper Sulphite, CUSO3. — Preparation of the Bouillie. —
Dissolve separately 2 lb. of blue vitriol and 2 lb. of sulphite of soda in
5 gallons of water; mix the two solutions and add thereto a solution of
1 lb. of bicarbonate of soda, make up with water to 20 gallons.

Properties. — Copper sulphite is a green precipitate sufficiently
soluble in water to act very energetically on the spores of all crypto-
gamic fungi. Unfortunately it possesses the fault of all salts of
sulphurous acid, that of burning the organs of the plant attacked.

Use. — Copper sulphite bouillie has been recommended against
oidium and peronospora. For this purpose about five sprayings a year
are required, the first of which is with a 1*0 per cent bouillie, and the
succeeding with a I'o per cent bouillie. Neither sulphurous acid salts
nor free sulphurous acid being capable of replacing sulphur in the
struggle against oidium, it is doubtful if copper sulphite possesses the
properties required to combat these two parasites of the vine simul-
taneously. Moreover, its use has not spread, owing to its corrosive
action on the leaves, an action which counterbalances its remarkable
anticryptogamic properties.

90. Sulphate of Copper, CUSO45H0O (blue vitriol, blue copperas).
— Preparation. — By roasting mineral sulphides of copper in reverber-
atory furnaces and in a highly oxidizing current of air. The mass
obtained is lixiviated with hot water and the blue liquor crystallized.

Properties. — Blue vitriol prepared thus is often impure.^ It is thus
less active as an anticryptogamic. That used to combat plant diseases
is prepared by oxidizing copper turnings in a reverberatory furnace and
dissolving the product formed in sulphuric acid. Crystals of copper
sulphate are dark blue, transparent, with a styptic taste. They
effloresce slightly in the air because above 15° C. they lose a part of, and
at 100' C. the whole of their water of crystallization. One hundred lb. of
water dissolve 36 lb. (10 gallons) of blue vitriol at 19° C, 88 lb. at 50° C,
and 213 lb. at 104° C. In medicine its emetic properties are utilized
in doses of 25-30 centigrammes. In croup it is administered even to

^ It in fact often contains green vitriol and zinc sulphate. If it be desireil to
detect these the blue vitriol is dissolved in water, and carbonate of soda or milk of
lime added. Pure blue vitriol gives a sky-blue precipitate, if it contains green
vitriol it gives a dirty-blue precipitate, if it contains zinc sulphate the precipitate is
of :i, pale bluish colour. [Perjxidize the solution with nitric acid, add large excess
of ammonia or potash (KPIO), filter, a brown residue= iron. The agricultural quality
of blue vitriol contains up to .50 per cent or more of green vitriol. — Th.]

202 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

children in doses of 1-2 centigrammes every ten minutes until the false
membranes are expelled. Blue vitriol is, moreover, a powerful disin-
fectant, used especially to disinfect linen soiled in cholera cases, typhus,
and other epidemic diseases. Blue vitriol is not poisonous to man to
the same extent as lead, mercury, arsenic, antimony, and phosphorus.
It acts as a caustic on the mucous membranes, and may produce, when
it is absorbed in abundance by the stomach, a gastro-intestinal catarrh,
which is rarely fatal. Given in certain regular doses it may interfere
with the functions of the nervous and muscular systems and produce
cachexy, but that disappears rapidly with the cause.

Blue vitriol coagulates albumen ; it is thus haemostatic like ferric
salts, but copper albuminates are soluble in alkalis, acids, alkaline
chlorides, and even in an excess of albumen. This property explains
the comparative harmlessness of copper salts which are regularly
eliminated by the kidneys. Absorbed by the stomach only a small
portion of it enters the blood. The stomach eventually tolerates very
strong doses. At the Salpetriere up to 125 grammes of ammoniacal
sulphate of copper were given to epileptic patients in 165 days. Blue
vitriol in doses of 25-60 grammes (383-920 grains) is generally fatal,
but cures are known after absorption of 125 grammes (1918 grains).
Such large doses are, moreover, difficult to swallow, the stomach soon
rejecting poisonous doses. Copper salts are more poisonous the
greater their solubility ; the oxides, as well as metallic copper, have
in fact little action on our organism. Contrary to an ancient pre-
judice, toxicologists admit to-day, with just reason, that copper salts
are but slightly poisonous. Dr. Galippe has shown that 50 centi-
grammes to 1 gramme of copper salts may be swallowed daily with-
out fatal accidents. Workers in copper, those who work in verdigris
factories, show no signs of poisoning even if, owdng to the daily ab-
sorption of copper, their hair, nails, and skin turn green, a colour
which, according to Petri, is produced by the deposit of microscopic
salts of copper. The copper daily absorbed would rather, according
to Dr. Pecholier, have a beneficial effect on the organism, an effect
analogous to that which is produced by iron salts. He has remarked
that chlorosis never exists in workmen engaged in verdigris factories,
and that workmen, anaemic when they entered, were quickly cured
of that complaint. The fear expressed formerly that the treatment
of vines by copper salts might introduce into the wine poisonous
substances injurious to the consumers is not, therefore, justified. The
doses borne by the human organism are much greater than those
which could be absorbed in articles of diet containing copper.
Different fruits treated with copper have been absorbed without in-
convenience (Fairchild). Moreover, 1 kilogramme of grapes, which
came from a vine treated with bouillie bordelaise in autumn, only con-
tained 17-35 milligrammes of copper, whilst preserved green peas
contain 11-125 milligrammes; the amount found in the wine is still
less. Accoi-ding to the analysis of Crolas, Eaulin, Gayon, Millardet,
Muntz, and Eossel, the maximum of copper found in wines, from
vineyards treated with copper bouillie, was from 2'5 milligrammes per
litre in red wines and 1 milligramme in white wines ; in the greater

COPPER SULPHATE (BLUE VITEIOL).

203

number of wines the average amount of copper does not reach
one-hundredth of a milHgramme. This amount of copper, contained
in wines, comparatively small in comparison with that which enters
into the vat, arises from the fact that the copper remains insoluble in
the lees. To prove it, it suffices to place a handful of blue vitriol in
the vat ; the copper will remain in the lees and not pass into the wine.
The tables prepared by Crolas, Eaulin, as well as by Millardet, show
this fact decisively.

TABLE XXV. — Showing the Distribution of Insecticidal and Anticryptogamie
Copper between Wine, Lees, etc.

Copper in lb. per 100,000 Gallons or
1,000,000 lb. of Wine.

Witie.

Picquette.

Marc.

Lees.

1 lb. blue vitriol in 40 gallons
water ......

1 lb. blue vitriol, 1 lb. ammonia in
40 gallons of water, eau celeste .

6 lb. blue vitriol, 1-5 lb. lime in 10
gallons water, bouiilie bordelaise .

0-23
0-2.5
000

0-00
0-14
0-1

11 0
12-8
10-4

49
81

92

1

The different parts of the vine treated by a copper bouiilie contain the
following amounts of copper in milligrammes per kilogramme : leaves
24-9-95-5; stem and wood, O'S ; grapes, lo-9-18-6 ; marc, 11-1-29-9;
wort, l'0-2"2; wine, 0"1. The amount of copper entrained into the
wine is so small that it does not even interfere with the fermentation.
The development of the ferments is not hindered up to 0"3 gramme
of blue vitriol per litre (Eommier), a dose, therefore, which can never
occur in wine. It must, therefore, be admitted, that before the action
of copper can make itself felt, a man must absorb several hundred
litres of wine a day.

Action of Blue Vitriol on Plants. — To ascertain the action of a
soluble salt on a plant the latter is grown in an artificial medium con-
tainmg a known dose of the salt to be examined. Haselhoff found
that the greater number of plants suffered in such conditions from a
small dose of blue vitriol. According to him the dose of 0*001 per cent is
injurious in almost all cases, but the deadly action of blue vitriol al-
ready shows itself in presence of 0"0005 per cent with certain plants,
and even with O'OOOll per cent (Devaux). Normal growth is im-
possible, except in presence of much weaker doses of blue vitriol.
Thus peas grow normally in a 0-00005-0-000001 per cent solution.
Maize grows in a O-000005-O-OOOOOOl per cent solution. Grain only
stands very weak doses of sulphate of copper ; the young plant is
killed by 0004875 per cent of copper bromide, 0-005 per cent of
copper chloride, 0-00555 per cent of copper sulphate, 0-005714 per
cent of acetate of copper, 00061 per cent of copper nitrate. It
follows from these experiments that copper salts are violent poisons to
plants when the roots are in presence of their solutions. Coupin's.

'204 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

table proves that copper salts do not act through their acids, as
Monselice asserts, but by their copper. The following are the suc-
cessive phases through which a plant, placed in a medium containing
a poisonous dose of blue vitriol, passes : If a branch of cryptomeria,
of Pinus or of Thuya, is dipped in a 0'01-0"05 per cent solution of
sulphate of copper, the chlorophyll contracts and ruptures and the
interior of the cell browns. If young plants be placed therein the
roots at first turn white, then become yellow and brown, grow up ab-
normally, then die. By analysing the different organs of a plant killed
by a solution of blue vitriol, Devaux found traces of copper in all its
parts. E. Otto, who submitted some plants {Phaseolus vulgaris,
Triticum vulgare, Zea Mays, Pisum sathnim) to the action of blue
vitriol in a nutritive solution, found, on the other hand, that these, in
spite of the deformation of their roots and their diseased state, only
contained a very little copper in the roots and none at all in the aerial
parts. Hence he concluded that blue vitriol is so poisonous to the plant
that as soon as it has penetrated into the cells of the root it there oc-
casions such disturbances that the plant dies before it can be conveyed
further.

This conclusion may be a sound one when the plant is placed in
contact with large quantities of a copper soluble salt, because in such
conditions the living cell is opposed to the osmosis of the salt. Nageli
also believes that blue vitriol kills the cell as soon as it is absorbed by
it, but that the latter does not suffer so long as it can prevent its pene-
tration. Nageli experiments on a green, fresh-water alga, Spirogyra,
which possesses, like phanerogams, chlorophyll and plasma, showed
that a solution of blue vitriol of 1 part in 100,000,000 sufficed to cause
the death of this alga. The effects produced on the chlorophyll and
the plasma are very visible under the microscope. The conditions
which we create artificially in a culture liquid do not exist, however,
on the large scale, and it would be rash to conclude by analogy that
blue vitriol acted in the same way on plants grown in the open field.
If the soil be watered with a solution of blue vitriol, chemical reactions
are produced between this salt and the soil which convert this soluble
salt into one or more insoluble compounds, and copper salts being more
poisonous the greater their solubility, insoluble salts such as oxide of
copper have no action on the plant. It is not necessary to go far to
find an analogous example. Mercury as bichloride, a soluble salt,
poisons man even in very small quantity. It no longer has any in-
jurious action when it is absorbed as calomel, an insoluble product.
These two salts, however, possess the same elements, chlorine and
mercury, but their different action on the organism lies in the fact that
corrosive sublimate, being soluble, coagulates albumen, whilst the
insoluble calomel passes through the organism without causing any
trouble. Similarly the plant shows signs of poisoning in presence of
blue vitriol, because the latter is soluble and capable of producing
copper albuminates, but it remains indifferent to the presence of insol-
uble copper compounds on the large scale. When solutions of blue
vitriol are spread round a plant this salt all falls into the soil, and the
roots are no longer in contact with a poisonous and corrosive liquid

r

COPPER SULPHATE (BLUE VITRIOL). 205

but in presence of an insoluble compound. The plant will absorb the
homoeopathic quantities which are beneficial to it, dissolving them by
means of the acid juices of its roots, by its chemical and physiological
exertions. The soil is capable of absorbing enormous quantities of blue
vitriol without the latter injuring the plant (the soil naturally contains
copper; Vedrosi found in arable land 001-0-15 per cent of copper
oxide, the average amount is from 0"06-0"08 per cent). Viala watered
vines in pots regularly for three months with a solution of blue vitriol
and mixed in this soil the dose of 200 grammes of this salt without
the vine perishing. Girard cultivated rye, oats, clover, and potatoes
on a soil treated with 1-J- metric tons of blue vitriol per hectare (1320 lb.
per acre). Taft concludes from his experiments that the soil does not
refuse to grow plants until it contains 1 per cent of copper. To prove
that copper sulphate incorporated in a soil is no longer soluble, Gorup-
Besanez watered 240 cubic centimetres of soil with a 0"1 per cent
solution of blue vitriol. This soil, washed at once with 500 cubic
centimetres of water, gave up no trace of copper to the water.
Similarly. Nobbe, who watered 152 grammes of dried soil with 150
grammes of blue vitriol was only unable to recover with 2 litres of
water 7"1 per cent of the blue vitriol used. In practice it has been
found that the watering of plants even with comparatively strong
solutions of blue vitriol is far from being injurious. On the contrary,
it is salutary. Eumm and Pichi found that vines watered with 5 per
cent solutions of blue vitriol, when the sap begms to circulate, resist
mildew and show a certain immunity to cryptogamic diseases. But
the amount of copper must not be too small ; 5^ gallons per stock of
a 1 per cent solution do not prevent mildew from attacking the vine.
But complete immunity is obtained with 5* gallons of a 5 per cent
solution. Besides this immunizing action blue vitriol possesses a
stimulating power on all the vital functions of the plant, like gi-een
vitriol; plants become vigorous, their leaves more fleshj^, of a deeper
green, and the vitality of the plant is prolonged. Hence it may be
concluded that the vine is capable of absorbing copper by the roots.
Is that possible ?

As far back as 1819 John experimented on the absorption of copper
by the roots. By mixing carbonate of copper with the sterilized sand
used for his cultures he could not find the presence of an abnormal
quantity of copper in the ash of the experimental plants. But when
these plants were watered with very small quantities of nitrate of copper,
the copper absorbed by the roots was ponderable. Peas cultivated in
this medium contained in their ash sufficient copper to give a red pre-
cipitate with j'eliow prussiate. The ash of barley, cultivated in the
same condition, contained it in such large amount that it could be
precipitated and estimated by iron. Buchhloz and Meissner also found
that roots could absorb copper under a form which it has not yet been
possible to define. Tschirch has shown that the potato absorbs the
copper applied to the soil, even though the latter is watered with 4
kilogrammes (8'8 lb.) of blue vitriol in solution per 2 cubic metres of
earth. The amount of copper absorbed is the greater the larger the
proportion of copper applied. These results also confirm the fact that

1306 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

copper is present in all plants, as it is recovered in their ash. Potatoes
contain 0'0028 grammes per kilogramme^ (Deschamps), haricots
0"002-0"011 grammes per kilogramme (Galippe), chicory, salad,
spinach, and clover also contain it, likewise the vine, the fig, and the
plum (Papasogli). A certain amount is found in beet (Langlois), in
pepper (Meissner), and in tobacco (Wicke). Vedrosi found 0'06 per
cent of copper oxide in oak w^ood, 0*02 per cent in the leaves, 0'04
per cent in the glands ; in haricots the proportion is gr-eater, and reaches
0"38 per cent ; in rye 0"19 per cent ; in wheat 0'21 per cent ; in barley
0"12 per cent ; in oats 0"35 per cent ; in maize 0"39 per cent. Whence
comes this copper if it were not absorbed by the roots ? This belief,
shared by De Candolle (1832), Francis Phillips (1882), Freytag (1882),
and others, has been disputed by many physiologists, who, for one
reason or another, have not found in plants treated with copper sul-
phate a ponderable amount of copper, or who have found that blue
vitriol was too poisonous to be entrained through the plant like nutri-
tive salts. Pichi, on the other hand, claims to have identified, under
the microscope, crystals of copper in the mesophyll of the leaves of
plants watered by blue vitriol, and Devaux's experiments prove that
copper, in an insoluble form, put in contact with the roots or the
leaves, is assimilated by them in infinitesimal quantities and carried
through the plant under the form of an organic compound, capable of
forming deposits in the cellular membranes. The difference of opinion
arises in the analytical processes which have been adopted for the de-
tection and estimation of copper in the sap or in the ash of plants.
It is wrong to try to determine in all cases the amount of copper by
chemical or physical methods, because they are not sensitive enough.
The amount of copper is often so minimum that it escapes detection
by the chemist. Deherain advises recourse to the extreme sensitive-
ness of the alga spirogyra, which is affected by the dose of 0 '000001 per
cent of blue vitriol. Ewert found a more sure method, based on the
presence of diastase, that is to say, on the stoppage produced in the
conversion of starch in presence of diastase, by infinitesimal doses of
blue vitriol, a method by which O'OOOOOOSl milligramme of blue vitriol
may be detected. If plants are visibly health}^ after watering with
copper salts, that results from the absorption of very small quantities
of copper that can only be determined by these latter methods of
analysis. It suffices to consider the infinitesimal doses of inoi'ganic
salts required to exert a stimulating effect on the human organism to
understand the role which copper plays in the plant.

The question then appears in quite another light, and it is in
homceopathic doses that soluble copper salts must be given to plants,
unless reserves of copper be formed round the roots of plants and
on the aerial organs with strong doses of insoluble or very slightly
soluble compounds. Wuthrich was the first to point out the analogy
which exists between the action of green vitriol and that of blue vitriol,
and that of corrosive sublimate on the spores of fungi. The physio-
logical effect produced on plants is likewise the same, since these three

1 = oz. per 1000 oz.

COPPER SULPHATE (BLUE VITRIOL). 207

compounds are capable of coagulating albumen and other nitrogenous
substances with which the life of the plant is intimately linked. The
intensity of their toxic action is in inverse proportion to their atomic
weight ; but keeping to these proportions blue vitriol is ten times more
energetic than gi-een vitriol, and mercuric bichloride 100 times more
active than the last. The same holds good as regards the stimulating
effect, that is to say, that to increase the assimilation in a plant it
requires 100 times less mercury and ten times less copper than of iron.
These salts are, moreover, not the only ones capable in small doses
of stimulating the vital functions of the plant. M. N. Ono found that
poisonous salts, such as zinc sulphate, cobalt sulphate, sodium
fluoride, and nickel sulphate, had in small doses lost their poisonous
properties and become stimulants. Eaulin found the same with salts
of zinc and of silicium.

In practice it has been found that blue vitiiol may render the same
service as green vitriol, but that for this purpose it must be used in
much smaller quantity. The analogy between the action of these
two salts is so striking that it has been seriously a question of attri-
buting this action to the green vitriol, very often present in commercial
blue vitriol ; they have even gone so far as to advise the addition of a
little green vitriol to blue vitriol to increase its stimulating action.
A manifest error was thus committed, which will be dealt with when
the action of bouillie bordelaise on the plant is considered. By
watering the aerial plant the same results were obtained as by water-
ing the roots, that is to say, the vital functions of the plant were
stimulated. But if large surfaces be placed in this way in contact
with a soluble salt of copper, the poisonous effects are felt more, and
leaf scald results from the too large quantities of salt absoi'bed. If
it be evident that the sulphuric acid of the blue vitriol, when liberated
by certain reactions, may exercise its well-knouTi corrosive action on
the organs touched, the poisonous action of blue vitriol is especially
due to the copper which, absorbed by the leaves as sulphate of
copper, kills the cells of the organs traversed. These drawbacks still
occur, even with 0*1 per cent solutions. Owing to this annoying
effect sprayings with blue vitriol have been abandoned, and given
place to copper bouillies. The latter, which contain copper in an in-
soluble form, copper hydrate, or carbonate, produce on the leaves an
insoluble deposit, of which the latter can absorb the amount beneficial
to them. Thus there are realized on the leaves the conditions created
around the roots by spraying with blue vitriol. From the foregoing
it follows that blue vitriol is a violent poison to plants, and that its
contact, always injurious to the plant, should be avoided. Neither blue
vitriol, nor any of the other neutral salts of copper, is the suitable
copper compound to be applied to plants. The pollen of flowers
being very sensitive to the action of copper salts even when insoluble,
forbids their application during the flowering of the plant. Miani
found pollen to have the same sensitiveness as fungi spores, but that
an infinitesimal amount of copper salts stimulated their vitality.

Action of Blue Vitriol on Algas and Saprophytic Fungi. —
Saprophytic fungi and algae behave to blue vitriol like phanerogamous

208 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

plants ; stimulating in small doses blue vitriol is poisonous in large
doses. It is to be remarked that blue vitriol shares this stimulating
action on algae with many other poisonous salts. Eaulin remarked in
1869 that zinc and silicium salts increased the vitality of the fungus
Asjjergillus niger. Nageli, Pfeffer, and Eichards made the same
remark on zinc, nickel, and cobalt salts, used on the fungus Aspergillus
niger and Penicilliwm glaucum, and on the algae Protococcus, Chroo-^
coccus, Stigeoclonium, and Hormidium. The vitality of fungi and algae
is, to sum up, stimulated by the sulphates of zinc, nickel, cobalt, iron,
and copper, mercuric chloride, sodium fiaoride, lithium nitrate, potassium'
arseniate. The right dose for algae is smaller than for fungi. For
blue vitriol the maximum dose is 0"012 per cent; for mercuric chloiide.
0-0013 per cent. Ferments (leavens) behave in the same way as fungi.
According to Kruger the alcoholic fermentation of wort by Saccha-
romyces ellipsoides is favoured by doses of blue vitriol smaller than
0-01856 per cent. Pichi and Eommier found that a solution contain-
ing O'Olo per cent of blue vitriol began to impede fermentation and
that 0'03 per cent reduced it perceptibly. Besides copper salts are
precipitated by fermentation, the ferments can thus find in the lees
the amount of copper favourable to their development (Biernacki and
Kruger). There are, however, exceptions amongst plants. Thus the
fresh- water algae spirogyra dies in a solution containing only 0 "000001
per cent of blue vitriol (Nageli), whilst other algae resist solutions of
0'012 per cent perfectly. Penicilliimi glaucum would even be capable'
of growing in a concentrated solution of green vitriol. This fact,
remarked by Trabut, was examined by De Seyes. In a nutritive solution
blue vitriol does not disturb the growth of Penicillium glauciim (Trab.).
in a 9'5 per cent dose. This fact must, however, be considered in
another light to understand it. It is, in fact, recognized that Peni-
cillium glaucum can grow in a poisonous medium without feeding on
its elements, but by using the medium solely as a support. Hence this,
mould is perfectly capable of growing on a crystal of nitrate of silver,
or in a solution of 1 per cent of corrosive sublimate. Whilst germin-
ating spores of Penicillium glaucum in a 9'5 per cent solution of blue
vitriol, De Seyes observed that growth did not occur except on the
edge of the vessel, where the water of condensation was accumulated.
Saccardo stopped all growth of this fungi in a medium containing
5 per cent of blue vitriol by agitating the solution ; whilst at rest
growth was so normal that it formed conidice. Penicilliwm therefore
does not possess a special immunity for copper salts, as had been
imagined, but behaves like other fungi, and E. Otto gives the dose of
O'OOS per cent as favouring its development. This dose is hardly
greater than that required by Aspergillus niger, O'OOl per cent.

Action of Blue Vitriol on Parasitic Funj^i. — Benedikt Prevost,
in 1807, discovered the ])oisonous action of blue vitriol on parasitic
fungi. In his experiments to determine the action of boiling water
on spores, he made the sensible remark that water boiled in a copper
vessel alone had the ])0wer to prevent spores from germinating. He
then determined that it suiliced for the water to contain 1 part in
400,000 of its weight of blue vitriol to prevent the spores'of rust from.

COPPER SULPHATE (BLUE VITRIOL). 209

germinating. The study of this phenomenon was pursued by Mathieu
de Dombasle. In 1858 Kuhn examined the comparative action of
blue vitriol and green vitriol, alum and sulphuric acid on the spores of
rust, an examination which still throws light on the remarkable
properties of blue \'itriol. In 1885 Millardet found the limit of toxicity
of blue and green vitriol on the zoospores of mildew, and found that
these could still germinate in a solution of 1 of lime to 10,000 parts
of water, of 1 of green vitriol to 100,000 parts of water, and 1
of blue vitriol to 10,000,000 parts of water. In 1889 Dufour
examined the action of blue vitriol on the spores of Fusicladium
pirinum, Claviceps purpurea, Pleospora, Phragmidnim, and other
fungi, and found that the germination was normal in a solution of
1 in 1,000,000, reduced 1 in 100,000, rare 1 in 10,000. In 1891
Wuthrich tried, comparatively, potassium nitrate, sodium carbonate,
zinc sulphate, zinc chloride, copper sulphate, and mercuric chloride
on the spores of Peronospera, Phytophthora, Ustilago, Puccinia, and
Clavicejjs, and made very instructive conclusions. Tried on the spores
of the most diverse fungi, blue vitriol has been recognized as possess-
ing a highly extensive poisonous capacity and capable of combating
the greater number of the cryptogamic diseases of plants. Wuthrich
was the first who described the action of blue vitriol on spores. He
determined the similarity in the action of different salts, and particu-
larly in that of blue and green vitriols. It has already been pointed
out that their action on spores appears to be inversely proportional to
their chemical equivalent, but that blue vitriol, regard being had to
these proportions, was ten times more energetic than green vitriol.
Wuthrich found that these two salts penetrated into the spores, and
that death only supervened after this penetration, whilst blue vitriol
could be detected in the cell by yellow prussiate, even in the case
where a spore had only undergone a slight alteration in its vitality in
contact with this salt. It is not the same with copper, which cannot,
be detected chemically in the same condition. Spores that have been
steeped in a solution of blue vitriol of 0*0001 equivalent per litre, a
dose which appreciably affects the vitality of the spores, absorbs so
little copper that its presence in the cell cannot be demonstrated by a
chemical reagent. The solution in the bath itself, moreover, gives no
perceptible tint with prussiate. It is different when the spore dies as
the effect of steeping in the solution of O'OOl equivalent per litre ; in
these conditions the dose of copper is sufficient to give a coloration
with prussiate. Wuthrich concludes, therefore, that a certain dose of
bl-ue vitriol may be absorbed by the spores without killing them, but
that this dose does not exceed a certain limit. The table on p. 210
shows how the spores of different fungi behave after being steeped in a
dilute sokition of blue vitriol.

Hecke, examining the action of blue vitriol on the spores of Ustila-ga
Crameri found that O'125-l per cent of blue vitriol did not kill the
spores, even those which had manifestly absorbed copper. A sub-
sequent washing of the spores with water in no way changed the effect
of the treatment, as is the case with spores treated with formol, but
washing with 0"5 per cent HCl reimparted to them all their vitality,

14

210

INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

TABLE XXVI. — -Showing the Effect of Solutions of Blue Vitriol of Variotis
Strengtlis on the Germinatio7t of Spores of Fungi.

Germination

Germination

Germination

Spores of

Normal

Abnormal

Nil

Per Cent

Per Cent

Per Cent

of Solution.

of Solution.

of Sohition.

Phytophthora infestans .

0000125

0-00125

0-0125

Petonospora viticola

0-000125

0-1 0125

0-0125

Uf^tilrtgo carbo ....

0-000125

00125

0-125

Puccinia graminis

0-000125

0-0125

0-125

Claviceps purpurea

0-000125

—

0-0125

In 0"125 per cent solutions of blue vitriol the copper disappears in five
minutes' immersion, and is fixed on the spores. Spores of different
species of smuts behave differently from this point of view.

Ustilago Panici-miliacei. — 0*5 gramme of spores absorbs all the
copper from 5 cubic centimetres of a solution of 0-125 per cent of blue
vitriol. 0'5 gramme of spores absorbs all the copper from 10 cubic
centimetres of a 0-125 per cent solution of blue vitriol. 0'5 gramme
of spores absorbs almost all the copper from 15 cubic centimetres of a
0125 per cent solution of blue vitriol.

Ustilago Crameri. — 0'5 gramme of spores absorbs all the copper
from 5 cubic centimetres of a 0'125 per cent solution of blue vitriol. 0*5
gramme of spores absorbs almost all the copper from 10 c.c. of a
solution of 0'125 per cent of blue vitriol. In the filtered liquid only
sulphuric acid (dilute) remains. The spores treated by 0 5 per cent
hydrochloric acid cede the whole of their copper to this acid and re-
cover their original vitality. Blue vitriol acts, therefore, like formol,
by fixing itself on the chitinous membrane of the spores of fungi and
preventing their growth ; treated by an acid this compound disappears,
and the vital functions resume their natural course as before treatment
with blue vitriol. It is not therefore surprising that blue vitriol cannot
be detected in the interior of the cells by chemical reagents, since in
small dose it does not penetrate but is retained on their surface. Al-
though blue vitriol in small doses does not kill spores it prevents their
normal evolution, and the object sought is found. The plant is safe.
The dose of blue vitriol, therefore, required to prevent the growth of
spores is very small, and it is not difficult to produce this effect, since
by spraying with copper bouillies the plant is covered by a layer of a
slightly soluble copper compound.

Action of Blue Vitriol on Insects. — The larvae of insects with
a wet skin are as sensitive to blue vitriol as snails. The adult insects
may be poisoned by absorption from the leaves sprayed with copper
compounds. The eggs of insects are much more insensitive to copper
salts than is generally believed, and to destroy them they require
steeping for a very long time in a strong sohition of blue vitriol.
Penoiicito has shown that the eggs of silk-worm (Bonibyx Mor/) easily
resist a twenty-four hours' immersion in a l)ath of 1-2 per cent of blue

COPPER SULPHATE (BLUE VITRIOL). 211

vitriol. In the same way caterpillars are not inconvenienced by con-
tact with blue vitriol solutions. Dufour found that a 10 per cent
solution did not nicoinmode the caterpillar of the CochyUs of the vine.
Mouillefert immersed vine roots bearing numerous phylloxera for three
days in a saturated solution of blue vitriol and still found many living"
insects ; it was only after five days' immersion that all the phylloxera
died. The great resist mce of this louse is, therefore, the cause of the
bad results obtained with the different processes of destruction recom-
mended in 1872 and submitted to the control of a special commission.
If blue vitriol cannot be regarded as a poison by contact, it, however,
becomes poisonous when absorbed by the leaves, and the favourable
results obtained by the bDuillie bordelaise admit of no doubt in the
matter. Besides, insects avoid gnawing the organs touched with blue
vitriol, and are thus removed by spraying. Targioni Tozzetti, having
steeped potatoes ia a solution of blae vitriol, found that the larvae of
the Elaterides did not touch them. In this way Angelr) met with
complete success against the phylloxera in the island of Elba, by in-
jecting blue vitriol into the diseised stocks. Dying vines revived by
this treatment, for the phylloxera disappeared from the stocks treated.

Use of Blue Vitriol to Kill Weeds. — Amongst chemical weed
killers, blue vitriol is one of the most efficient. Bonnet, a vine-grower,
found it out fortuitous'y. He observed that the mu-tard which grew
amongsu the vines was destroyed by blue vitriol, whilst oats, growing
in the same condition, were immune. Trials made by Benard and
Brandin showed that a 5-10 per cent solution of blue vitriol disorganized
the cruciferae growing amongst cereals without injuring the latter. Its
disorganizing action is more powerful than that of green vitriol.
Whilst it requires 15-20 per cent of this latter salt, 4-5 per cent of blue
vitriol suffices to produce the same effect, at the raie ot 41-88 gallon-^ per
acre (Dussere). It is better to use mixtures of blue vitriol and nitrate
of soda as weed killers. The young plants are destroyed by a mixture
of 2 per cent of blue vitriol and 10 per cent of nitrate of soda, sprayed
at the rate of 8-10 hectolitres per hectare (70-4-88 gallons per acre).

Use to Destroy Parasitic P. ants. — Guscuta minor, D. C. (small
dodder of the luqerne and clover) ; CusciUa densi flora, Willm (dodder
of flax) ; Guscuta major, D. C. (large dodder of the hop and hemp
plant). — Blue vitriol kills dodder in much smaller doses than green
vitriol. From 2-5 per cent solutions of blue vitriol suffice. Their
method of use is the same as for green vitriol.

Orohanche ramosa (branchy orobanche of hemp and tobacco) ;
Orobanche minor (clover orobanche). — Gennadius advises to destroy
these parasites by a 5 per cent solution of blue vitriol, which destroys
their seeds.

Use against Mosses and Lichens. — Coating with a mixture of
6 per cent of blue vitriol and 2 per cent of sulphuric acid readily de-
stroys the mosses and lichens which grow on the trunks of trees.

Use against Cryptogamic Diseases of Plants. —Phytophthora
infedans, De By. (potato disease). — The analogy between the Phyto-
phtJwra and the Prr)?Jo.s7;ora, combated with so much success by
copper salts, led to the belief of an analogous efficiency of these in

212 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

preventing the potato disease. However, numerous experiments
with this end in view gave less decisive and less concordant results
than with mildew of the vine, but there is now no doubt that ths
methods used to prevent mildew of the vine are equally efficacious to
avoid the Phytophthora. Petermann, after three treatments, only ob-
tained 35"960 kilogrammes of potatoes instead of 4:6'370 on an un-
treated plot amongst which there were only 2'5 per cent of diseased
potatoes against 11"3 per cent in the check plot. Montanari found
that there were as many diseased tubers in the fields, sprayed with
0"25, 0"5, and 1 percent solutions of blue vitriol, as in those untreated.
These results show that the method of application has a great influence.
Frank and Kruger have shown, on the contrary, that a general pre-
ventive and judicial treatment of the potato increases its assimilative
capacity, which is manifested by an over-production of potatoes rich
in starch, but that it is necessary to choose other compounds than
blue vitriol to attain this end, the scorchings occasioned by sprayings
of blue vitriol, to which the potato is more sensitive than the vine,
being often the cause of smaller crops of tubers.

To produce this favourable result it must not be forgotten that the
infection of the potato may be produced either by conidia, brought on
to the leaves by the wind, or by previous infection of the tubers. To
be complete, therefore, the treatment ought to be double. (1) Dis-
infection of the seed tubers, four to five weeks before planting, so as to
prevent the propagation of the disease by the tubers. (2) Eepeated
preventive spraying with copper preparations against the aerial in-
vasion. The cupric treatment which can prevent the rapid progress
of the disease, and its extension in potato fields, by annihilating the
conidia produced during summer, can in no way destroy the mycelium
which lives in the interior of the leaves and the stems, nor prevent
the progress of the disease on the infested tubers. The treatments
must therefore be preventive and capable of killing the conidia or the
zoospores which fall on the leaves, so as constantly to oppose the inva-
sion of the plant by this disease. By observing all these necessary con-
ditions the cupric treatments are crowned with the same success as
the preventive treatment for mildew of the vine. This point will be
dealt with more fully in describing the treatment of Phyto2)]ithora by
bouillie bordelaise. This latter, used judiciously, is so superior to blue
vitriol that the latter has been abandoned. Sorauer recommends
" cupric-sulfosteatite," a mixture of 10 per cent of blue vitriol and
90 per cent of talc, to combat the disease of the tomato. This pre-
paration is added to the manure and sprayed at intervals of four to
five days, and after transplanting every eigbt to ten days. Care must
be taken not to use too much, for it may scorch the plant. Used
against the potato disease, sulfosteatite has given results varying from
one species to another. Whilst Liebschei' declares that its use lowered
the crop 31 per cent and Steglich found it without action, Schoyen,
Holliung, and Strebel obtained in many cases superior yields up to
26*3 per cent. All are, however, agreed that its results are not so
regular as those obtained with neutral bouillie bordelaise.

f'eronospora viticola, De By. (mildew of the vine). — Owing to

COPPER SULPHATE (BLUE VITRIOL). 213

its purely aerial propagation the mildew of the vine is much easier to
destroy than the j^hviophthora. It suffices to prevent the disease to
stop the zoospores from germinating by poisoning them. There can
be no question of destroying the mycelium in the tissue of the leaves,'
and if the disease has invaded the plant the treatment must be con-
fined to preventing the propagation of the disease to neighbouring
plants by the conidia coming from the plant attacked. Cupric prepara-
tions, by depositing on the leaves an adherent and slightly solub'e
layer, creates an insurmountable barrier to the spores of this fungi.
As 2-3 ten-millionths of this salt soluble in the dew suffice to prevent
the zoospores from germinating, it will be seen that the layer of the
cupric compound lying on the leaves will always cede this amount to
the water deposited on the leaves. The most active and efficient pre-
parations are, therefore, those which possess a very weak solubility
with perfect adherence. Blue vitriol is the copper salt which realizes
these conditions to the least extent ; it has therefore been replaced by
the bouillies which give much better results and never injure the vine.
When in 1884 it was seen in Burgundy and Maconnais vineyards,
ravaged by the Peronosjjora, that certain stocks preserved a normal ap-
pearance, it was found that those which were exempt from the disease
were attached to new props, impregnated with blue vitriol to preserve
them. This observation was communicated to the Academy of Science
by Perry, who observed it himself in the department of Saone et Loire.
Experiments were made the following year by Paulin, using vitrio-
lized props throughout a whole vineyard, and by Prosper de Lafite, by
simply steeping the ropes of straw or willow skins in a bath of blue
vitriol. But these experiments were soon followed by a bolder and
more rational ti'eatment, consisting of spraying with more or less dilute
solutions of blue vitriol on the foliage of the vine. These treatments,
which enabled the invasion of mildew to be victoriously contended
against, were, however, far from giving entire satisfaction. The pro-
portions of blue vitriol used ia the beginning were from 1-15 per cent.
In 1885 Muntz recommended the treatment of this disease by 10 per
cent solutions of blue vitriol. But there followed scorchings of the
leaves ; it is true they were not serious, but all the same alarming.
The doses were reduced, owing to these mishaps, to 3 per cent,
then to 1 per cent, and then by Bouchard and Beaume to 0'3 per
cent. With this dose Ricaud got the same preservative result as with
the larger doses. In spite of this small dose of blue vitriol the vines
showed the same characteristic burning, especially when the spraying
was done in hot, warm weather, because the drops of this dilute solu-
tion deposited on the leaves concentrated rapidly, and then acted like
a concentrated solution. Blue vitriol, used against vine diseases, pos-
sesses two defects : (1) injuring the foliage, (2) possessing no adher-
ence on the leaf ; rain removed all the blue vitriol deposited thereon.
To obtain with these solutions the same effect as with bouillies, it
would be unceasingly necessary to multiply the treatments, and in
these conditions the advantage of blue vitriol being cheaper, as compared
with l)ouillies, entirely disa,ppears. Blue vitriol sprayings have also the
drawback of leaving no visible trace on the leaves, whilst bouillies

214 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

enable the work to be controlled owing to the blue spots which they
leave on the organs touched. In spite of these drawbacks blue vitriol
is still used in 025 per cent solution in Le Tarn, owing to the low
cost of the spraying. To give adherence to blue vitriol Trabut advises to
add mucilaginous substances to its solutions ; the mucilage extracted
from the prickly pears of the Barbary fig-tree, and galipot, a dry
resin which exudes the whole length of the Algerian pines, previously
dissolved in carbonate of soda. The galipot soap bouillie has the fol-
lowing composition : galipot, 1 lb. dissolved in ^ lb. of soda crystals ;
blue vitriol, ^ lb. ; water, 10 gallons. The bouillie with the Barbary fig
mucilage basis is made thus : 3-5 lb. of the prickly pear of the Barbary
fig are cut up and macerated in water. After extraction of the muci-
lage i-^ lb. of blue vitriol is added and the mixture made up to 10
gallons. These preparations effect a saving of 50-80 per cent of blue
vitriol and are cheaper in Algeria. They are to be recommended in
countries where rain is rare, and where the number of sprayings neces-
sary do not exceed those with bouillies. Viala's, Pichi's, and Rumm's
experiments show that mildew may be contended against by spraying
round the stocks with blue vitriol solutions ; this salt would therefore
possess serious advantages over bouillies. Unfortunately the doses
required to obtain immunity are such that there can be no question of
employing this treatment on the large scale. From experiments of
Chmjelewsky it follows that blue vitriol has a deadly action on fructi-
fication. Beach and Bailey also found that it was deadly to pollen ;
0'02 per cent solutions lower its vitality, and it is killed when it comes
in contact with 0"5-2 per cent solutions. If the flower be open for
some days only before the treatment the action of the blue vitriol is
less injurious. Spraying with blue vitriol should thus be avoided
during flowering if it is not desired to do great damage to the crop.

Use of Mixtures containing Blue Vitriol. — As the vine-grower
already was accustomed to distribute flowers of sulphur with a bellows
to contend against oidium, the operation of treating the mildew would
have been greatly simplified if it had been possible to use blue vitriol
in a pulverulent form mixed with sulphur. A great number of analo-
gous mixtures have been compounded in different countries. They
either contain blue vitriol mixed with powdered inert bodies, or are the
elements of cupric bouillies with or without sulphur. With some rare
exceptions, the adherence of these is much less than that of cupric
bouillies which renders them liable to be carried off by the wind and
by the first rain. It is also necessary to apply them in the dew of the
morning, so as to render them a little more adherent. It will be seen,
therefore, that these preparations cannot be regularly used except in
moist countries, and that those which contain sulphur cannot produce
on the oidium the categoric effect of sulphur alone used at a full heat.
To increase the adherence of blue vitriol on the leaves it has been
mixed with substances liku talc, powdered coal, alumina, sulphate of
lime, and sugar, or it has even been dehydrated and reduced to an
impalpable powder by calcination. The latter preparations are the
only ones of any real use in cei'tain circumstances. Powders consisting
of pulverized blue vitriol and various other bodies, mixed by grinding,,

COPPER SULPHATE (BLUE VITRIOL). 215

are defective from the fact that projected on to the plant, the different
densities of the products of which they are composed produces a separa-
tion, causing an irregular distribution of the blue vitriol. On the other
hand, powders prepared like " Cupric Sulphosteatite " do not possess-
this drawback. Besides this drawback preparations w'hich contain blue
vitriol have all the defects of its solutions. These drawbacks make them-
selves felt when it is a question of using these powders against the
cryptogamic diseases which affect delicate plants. The intense scorch-
ings may have disastrous effects from the point of view of the yield of
the plant. But the powders are easily distributed, and that is their
great advantage. Their jtidicious use in special cases may save a
vineyard from a sudden attack. The grower sometimes uses powders
which enable him to dispense with bouillies, and when the vineyard
is far from a dwelling, extensive, and without water, the carting of the
necessary water to manufacture these bouillies. The appliances used
are those utilized for sulphuration. However, as blue vitriol attacks
leather, only bellows with exterior case can be used. In spite of the
numerous disadvantages of powders many vine-growers have adopted
the cupric sulphosteatite, which is the best of all these preparations.
They use it at the same time as the bouillies, but this powder ought
not in general to be used, except as a supplement to liquids, when the
foliage is so thick that it prevents the uniform penetration of the
bouillies. It is good to protect grapes for it penetrates more readily
amongst the grapes as compact grains. Exact details will only be
given of one of the preparations of this sort, the ciipric S2(IpJwsteatite,
compounded, like Fostite's powder (Poudre Fostite), of blue vitriol 10
per cent, talc 90 per cent. It is prepared by pouring on the talc in
powder a saturated solution of blue vitriol. The resultant paste is
dried, ground, and sifted. It is a bluish powder, which, owing to its
lightness, penetrates as far as the interior of the vines with the most
dense foliaee. Used in the morning dew its adherence is so good that
traces of it may be seen two months afterwa,rds, even w^hen violent
storms have washed the leaves. Owing to this property it has given
perfect results at Montpelier in assuring complete preservation of the
vine. It has been especially recommended for destroying the mildew
of grapes, for owing to its tenuity it penetrates everywhere, and the
rapidity with which it can be applied enables the crop to be saved at
the time of a sudden invasion. If it be desired to use it alone for
mildew^ (which cannot be advised in spite of its properties, for bouillie
bordelaise is still superior), three applications are necessary, at the
rate of 20-25 kilogrammes per hectare (17-6-22 lb. per acre). The
first should be done eight days before flowering, the second five weeks
after the first, and the third in the middle of July. If there be mildew
in the neighbourhood, and late invasions to be feared, supplementary
applications must be given. Pulverizations with powders containing
blue vitriol are always injurious when they are made during flowering.
Amongst the numerous preparations on the market the following may
be quoted as intended for making bouillies by mixing them with water,
or to l)e pulverized such as they are by aid of a bellows. Their com-
position has been given by Barth, of Colmar : —

216 INSECTICIDES, FUNGICIDES, AND WEED KILLEKS.

Poudre " Coignet ''. — Intimate mixture of 10 per cent blue vitriol and
90 per cent of gypsum, recommended by Klening and Wuihrich against
Phytophthora.

Sulfatme. — Mixture of 73 per cent sulphur, 7 per cent blue vitriol,
and 20 per cent of lime ; used in America against the black rot.

Kupferschivefelkalk, mark CuSCa. — Mixture of 70 per cent of sul-
phur, 6 per cent of blue vitriol, and 24 per cent of lime, recommended
in Germany by Schoyen to contend against mildew of the vine and
oidium, and even PhymphtJiora. It has little adherence (Thiele).

Bouillie bordelaise celeste in a single 2)owder. — Mixture of
49-74 per cent of blue vitriol, 15-1 per cent of lime, and 35-16 percent
of carbonate of soda.

Skavi)isky's Poivder, consisting of blue vitriol 20 per cent, lime 6
per cent, ground coal 74 per cent.

Skavinsky's Sulplmr. — Blue vitriol 10 per cent, sulphur 50 per
cent, lime 3 per cent, powdered coal 37 per cent. These two powders
can only be used as supplementary applications when the foliage is
too dense. They adhere badly.

Kupfer Klehekalkviehl. — 1896-7 Prep)aration — Blue vitriol 26, argil-
laceous clay 74 = 100 calcine. 1898 Prepai-ation — 22-5 per cent of
blue vitriol are neutralized by carbonate of soda and mixed with oxide
of alumina and china clay. This latter preparation is very adhesive,
and is used for making bouillies.

Kupferzuckerkalkpulver. — Calcined blue vitriol 40 lb., powdered
slaked lime 50 lb., powdered sugar 10 lb. = 100 lb. mix.

Cuprocalcit. — Blue vitriol 20-25 lb., argillaceous carbonate of
lime (? marl) 75-80 lb., per 100 lb. It is used in the dew, or as a
bouillie, 1 lb. to 1^ gallons water. To strengthen its action it is re-
commended to add 1^ gallons of ammonia to 100 gallons of bouillie.

Cupreina possesses the composition of evaporated bouillie borde-
laise ; used to make a bouillie, only gives imperfect results.

Occidine. — Mixture of blue vitriol (7-5 per cent), green vitriol, sul-
phur, naphthalene, and carbonate of lime.

Powders having the Composition of Bouillie Bordelaise,
Burgundy Bouillie, and Eau Celeste, intended to be diluted
with Water and used exclusively as Bouillie : —

Pauisiticine. — Mixture of blue vitriol 57 per cent, carbonate, and
bicarbonate of soda.

Antmiildioidium. — Mixture of blue vitriol 39 per cent, and car-
bonate of soda.

Poudre Crochepeyre. — Mixture of blue vitriol 53 per cent, and
bicarbonate of soda.

(lelatinoHS Cupric Ilydrorarbonalc. — Mixture of blue vitriol 32
pel' cent, with carbonate and bicarbonate of sodn.

Houillie d'Azur. — Mixtui-e of blue vitriol 48 per cent, and of
bicarbonate of soda.

Poudre Eclair. — Mixture of blue vitriol 30 per cent, acetate of
soda, lime, and acetic acid.

Foslitehruhe. — Mixture of blue vitriol 50 per cent, carbonate of
soda and lime, tinted with aniline blue.

COPPEE SULPHATE (BLUE VITRIOL),

217

Krystallazurin. — Ammoniacal copper sulphate (70 per cent of blue
vitriol).

Kiipferpreparaf Gmnnd. — Emulsion of ammoniacal sulphate of
copper (blue vitriol 20 per cent) in water, and 11 per cent of oil.

Kupfer soda, etc., etc.

Use against Smut [Ustilaginece). — It follows from the mode of
propagation of rust diseases that only the disinfection of the corn-seed
and the dung can prevent the cryptogamic diseases of grain crops ;
that no spraying can lessen, contend with, or prevent. Amongst
chemicals used to disinfect seed-corn blue vitriol is one of the most
powerful and the one in current use. The only drawback lies in the very
decided sensitiveness of the grain to solutions of this poison. Different
[chemical] agents have not the same effect on the germination of
the seed. Chlorine water and lime water exert no injurious action ;
mineral acids retard germination without lessening the germinative
capacity, whilst metallic salts, such as green vitriol, blue vitriol, sugar of
lead, and others, are poisonous in small doses ; a germination of 100 per
cent is only obtained by observing certain limits of concentration, special
to each salt. In disinfection with blue vitriol a 0"5 per cent solution must
not be exceeded. More concentrated solutions yield the following : —

TABLE XXVII. — Showing the Effect of Steeping Seed-Corn in Solutions of
Blue Vitriol of Different Sire?igths for Different Periods of Time.

Strength
Per Cent.

Time of
Action.

Loss of

Grains

Per Cent.

Strength
Per Cent.

Time of
Actioji.

1
Loss of
Grains
Per Cent.

1
2
2

15 minutes

15

39 „

10
14

28

2
2
2

1 hour

2 „

3 „

46
54
59

The strength of the solution of blue vitriol and the duration of the
steeping ought to be such that the blue vitriol cannot enter into the
interior of the grain, but is confined to the disinfection of its exterior
surface. As soon as the poisonous salt penetrates into the seed
symptoms of poisoning are to be seen in the future plant. With solu-
tions of different strength the following result w^as obtained : —

TABLE '^XVlll.— Showing the Effect on Height of Plant of Steeping Seed-Corn
in Solutions of Blue VitrioL of Variotis Strengths.

Strength
Per Cent.

Time of
Steeping.

Height of
the Plant.

Appearance

after
Ofie Month.

Blank
0-5
1-2
3-5
10

2 hours
2 „
2 „
2 „

8-12 inches \
10-12 „ /

8-10 „ 1

6 „ J

Normal

Dark
Colour

218

INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

The greater the number of deep wounds sustained by the grain in
threshing the more sensitive it is. When the grain is wounded noth-
ing prevents the penetration of the copper solutions into the interior of
the grain, and the embryo may be killed by a short immersion in a
bath of blue vitriol. Ivans and Welter have made categoric experi-
ments in this direction with grain wounded for the purpose.

TABLE XXIX. — Showinq Effect on Germination of Steeping Injured Grain in
Water and in Solutions of Blue Vitriol.

Nature of Injury
to Grain?.

Immersion
in

Germination.

i cut from side op- )
posite embryo j

Epiderm of embryo ^
slightly damaged j

Cheek
Treated

Cheek
Treated

Water

2 per cent solution

of blue \ itriol

Water

2 per cent solution

of blue vitriol

90

44

40

Nil

The un wounded test samples were not injured by steeping from one to
two hours in a 0*5 per cent blue vitriol solution, and even a 1 per cent
solution when the action of the blue vitriol was stopped by a bath of
milk of lime. Now it is a well-known fact that the threshing of grain
in the threshing-mill damages about 30 per cent, whereas hand
threshing [with the flail] does much less damage. This 30 per cent is
generally killed by steeping in a solution of blue vitriol, so that it is
necessary to use, in general, 30 per cent more seed to sow the fields
when such corn-seed, disinfected by blue vitriol, is used. After a pro-
found examination of the subject the greatest authorities, Deherain,
Grandeau, Vilmorin, Sorauer, Loverdo, Brefeld, and others, agree on
the superiority of the blue vitriol method, used rationally, over other
methods of disinfection ; it alone possesses the property of still acting
after the sowing of the seed-corn within a certain radius of the latter.
It protects them during the period the plant is vulnerable from the
germs found in the soil, or which have been brought on to the land
with the dung. From that point of view blue vitriol is superior to hot
water, sodium sulphide, sodium sulphate, the disinfectant property of
which is, however, analogous and the efficiency incontestable. How-
ever, blue vitriol, so as not to injure grain, must be used, in a rational
manner ; the steeping should be as short as possible, and its action
stopped at the right moment by converting it into an inert and insol-
uble derivative as soon as it has played its role of disinfectant. The
methods recommended by Benedikt Prevost, in 1807, were not much
altered by a deeper examination of the subject by Mathieu de Dom-
basle. By describing a practical method of disinfection the latter,
however, largely helped to make this process genei^al.

Here is his process : Dissolve 1 lb. of blue vitriol in hot water and
make up the bulk to 20 gallons. Immerse the corn-seed into this bath
in such a way that a layer of liquor, 4 inches in de])th, remains above
the seed. Stir several times and remove all the floating grains. After

COPPER SULPHATE (BLUE VITRIOL). 219

twelve hours' steeping remove the seed and spread it on a board. It
must be turned frequently. By this prolonged immersion and stirring
the air adhering to the grain, often with tenacity, is gradually dis-
placed, and the liquid touches their whole surface. Corn-seed so
treated does not keep. Like all grain moistened and sw'ollen by
steeping it heats and spoils ; blue vitriol then exerts a deadly action on
the seed and kills a large quantity. Jt is thus absolutely necessary to
sow the corn-seed as soon as possible, and as soon as it is dry again.
If the operation be commenced at 4 o'clock in the morning it is
finished in the evening ; the next morning the corn-seed dismfected
by the blue vitriol is bapged up in sacks, conveyed to the field,
and sown as soon as possible. In spite of all precautions, loss in
using this process is unavoidable, for the blue vitriol is concentrated,
in drying, around the grains, where it acts as a concentrated solution.
To remedy this drawback weaker solutions have beeji tried. If grains
are only immersed for fifteen minutes in a 0"5 per cent solution they
undergo no damage, and 99 per cent germinate, often even before the
untreated grain ; after steeping for three hours the grain does not
germinate until three days after the untreated grain (experiment on
oats, variety Scotch White Superior).

Bloymeyer advises a still shorter immersion, carried out thus :
Eun the corn-seed into a basket and dip that for one minute into a
1 per cent solution of blue vitriol. Drain and dry. if the time of
steeping be considerably shortened, it is owing to the great concentra-
tion of the bath of blue vitriol. Herzberg found that the temperature
of the blue vitriol solutions played a very important role. Below
8° C. the blue vitriol bath is, so to speak, without action on the spores
of Ustilago (smut), whilst a solution at 24°-26'' C, even if it only contain
O'l per cent of blue vitriol, kills them instantly. This is explained by
the fact that the spores are very resistant, but that the sporidia are
very sensitive. By inducing their formation by a high temperature,
the above resub is obtained ! Herzberg, therefore, recommends
steeping for twenty-five hours in a 0"1 per cent solut'on at 25° C.
The spores of Tilletia (bunt) do not behave similarly. They rather ap-
pear to be more sensitive to cold solutions ; the most favourable tem-
perature is from 6°-8° C. At that temperature a solution of 0'0004
per cent prevents their future evolution. This fact was pointed out by
Prevost as far back as 1807, who gave 6|" and 7^" C. as the extreme
temperatures to which these spores are most sensitive ; at the ordinary
temperature the immersion ought to last half an hour in a 0"05 per cent
solution ; at a higher temperature these solutions, therefore, have no
action. Wheat, therefore, infected with germs of Tilletia (bunt) ought
to be disinfected, according to Prevost and Herzberg, at a low tempera-
ture, whilst barley and oat seed infected with Ustilago (smut) should be
disinfected between 24° and 26° C. Treatment by blue vitriol alone
is abandoned now, because it is too often deadly. An injurious
action has been found on grain after steeping one hour in a 0"1 per
cent solution. The growth of the radicles is often affected to such
a point that they do not form although the plumule may be long
enough. When the radicle emerges its point is brown, and remains.

220 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

sickly for some time. To avoid this annoying action of blue vitriol,
produced after steeping (an action vphich is always dangerous because
the adherent liquid becomes concentrated), a second steeping must be
given, capable of removing this secondary action from the blue vitriol.
Kuhn was the first to wash the disinfected grain and immerse it in a
6 per cent milk of lime. This method, which suppresses all the draw-
backs of blue vitriol, has met with a wide response. It is in common
use in Germany. Steglich places the corn-seed in a basket, dips it
into the blue vitriol solution, takes it out and at once dips it into a
solution of carbonate of soda. The copper carbonate which forms an
insoluble layer round the grain is without any injurious action on it,
but it is a very effectual protection against infection, which may occur
after sowing. Hollrung altered this method ; he steeps the grain in a
vat containing only a 0"3 per cent solution of blue vitriol. After
stirring the grain for four hours he takes it out and washes it for thirty
minutes in a 04 per cent solution of milk of lime. The seeds are
then spread on the floor in a thin layer and frequently turned. Each
operation should be done in warm weather. In spite of all experi-
ments on steeping, on the concentration of solutions, and on the
temperature, Kuhn's process is used in actual practice, the steeping
in a blue vitriol bath being followed by a passage through milk of
lime. The dangers of too strong solutions being thus much diminished
reversion was made to solutions of O'5-l per cent used in immersions
of short duration. This operation, always long with dilute solutions, is
thus greatly shortened. The following method most used in France
was recommended by Deherain and Loverdo and popularized by the
Minister of Agriculture. Dissolve 50-100 grammes (772-1543 grains)
of blue vitriol in 10 litres (2-2 gallons) of water ^ and dissolve this in a
vat containing 1 hectolitre (2| bushels) of corn-seed, then add water
until the grain is covered with a layer of liquid 4 inches deep. Stir
the mixture. Eemove the seed which float, then drain the remainder
in a basket. After an hour dip the grain into fresh water, and
dust with slaked lime (chaux fusee). To prevent any delay in
germination Bernard advises a steep of the following composition : 50
grammes of blue vitriol (772 grains), 300 grammes of nitrate of soda
(4632 grains), and 300 grammes of superphosphate (4632 grains) in 10
litres of water. After a short immersion in this steep the grain is
pralined with ashes or slag. Seed-corn so treated has always shown
a certain advance in its growth, and given higher yields because the
plant finds after brairding a zone rich in nutritive substances. An
analogous result is obtained by the repeated spraying of wheat in a
heap. When all the grain is well impregnated with blue vitriol the
heap is dusted with slaked lime. This method has the advantage over
immersion of precipitating aroimd the grain a strong layer of hydrated
oxide of copper, which adheres very well to the surface and prevents
ulterior infection by contaminated dung, but this process requires much
handling for it requires continual shovelling.

1 That is to say, at the rate of 5 lb. to 10 lb. of blue vitriol in 100 gallons of
■water, and of this solution use 1 gallon for every bushel of seed-corn. — Tu.

COPPER SULPHATE (BLUE VITRIOL),

221

In spite of the perfection of the processes in use, even if there be
no doubt of the superiority of this treatment over others, with the
same end in view, loss of grain is inevitable, and it is necessary to in-
crease froni 20-30 per cent the amount of seed sown to prevent too
thin sowing, although in practice there is only one treatment for all
the cereals.

Barley. — Hordeum vulgare is infested by Ustilago hordei, Bref.
and Hordeum distichum by Ustilago Jensenii, Rost.

TABLE XXX. —Showing Effect on Germination of Seed Barley of Steeping in
Solutions of Blue Vitriol of Various Strengths.

Grain.

Duration
of Steep.

Strength

of Steep

Per Cent.

Germination
of Grain
Per Ce?it.

Treated
Check

24 hours

0-5
1
2
5

88
64
48
35
98

TABLE XXXI. — Showing Delay in Germination by Kuh7i's Treatme7it.

Soil.

Grain.

Germination Per Cent.

3?-a Day.

1th Day.

lUh Day.

26f/i Day.

Sand
Soil

Untreated
Treated

Untreated
i'reated

271

95
971

45-7
60-4

86-7
89-0

T.\BLE :s.Wll.— Showing Effect of Bhw Vitriol Pickle on Crop of Barley.

Grain.

Number
of Ears.

173
243-7

Rust.

Weight of

Grai7i.
Grammes.

Weight of

Straw.

Grammes.

Untreated
Treated

4

104-5
161-9

185-5
184-2

These experiments were made by Hollrung in using Kuhn's method
of disinfection, 0-5 per cent blue vitriol and 6 per cent of milk of
lime.

Oats. — Avence sativa is infested with Ustilago Avence, Rost. ;
Avence elatior is infested with Ustilago perennans, Rost.

•222 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

TABLE XXXIII. — Showing the Sensitiveness of Seed Oats to Blue Vitriol

Pickle (Gaillot).

Duration
of Steep.

Strength

Germination

Grains.

of the Steep,
Per Cent.

of the Grain,
Per Cent.

Treated

24 hours

0-5

45

24 „

1-0

20

24 „

20

10

24 „

5-0

0

6 „

0-5

98

30 minutes

1-2

98

Untreated

—

—

98

TABLE XXXIV. — -Showing the Delay in Germination by Blue Vitriol Pick-
ling of Seed Oats (Kuhn's method).

Soil.

Grains.

Germination, Per Cent.

Uh Day.

76i
43

1th Day.

Uth Day.

26th Day.

Sand
Soil

Untreated
Treated

Untreated
Treated

935

5U

54-|

93J^

88|

TABLE XXX.Y.— Showing Effect of Kuhn's Blue Vitriol Pickling of Seed
Oats on the Oat Crop (HoJlrung).

100 Grains
of Seed Oats.

Number
of Ears.

Rust.

Weight of
Grain in
Grammes.

Weight of
Straw in
Grammes.

Untreated
Treated

891
771

5

107-7
'.0-5

157-1
205-8

Disinfection by HoUrung's method does not cause this diminution in
the crop so perceptible in Kuhn's method.

WJieat. — Triticuvi sativiim is invaded by Ustilago Tritici, Jensen
(smut of wheat) ; Tilletia caries, Tul. ; Tilletia leris, Kuhn (stinking
smut bunt of wheat). — It is particularly on this fungus that Prevost
tested the action of blue vitriol. By disinfecting " spotted " f^rain, that
is to say, covered with spores of Tilletia (bunt), he obtained : Spotted
non-treated grain, 486 per 1000 of rusted ears ; spotted treated giain,
8 per 1000 of rusted ears, after steeping half an hour in a 1'2 percent
solution. Whilst blue vitriol used alone greatly reduces the germinative
cajjacity of the barley, this treatment of Kuhn has not that drawback.
Grain treated with Ovj per cent solution of blue vitriol, however, does not
show it if sown immediately (Grassmann).

COPPER SULPHATE (BLUE VITRIOL),

223

TABLE XXXVL-

-Shoiving Reduction in Gerniinative Capacity by Delay ifi
Sowing after Pickling with Blue Vitriol.

Grain.

Untreated grain
Treated grain sown

1st day after disinfection
2nd „
3rd „
4th „

10th „

Loss Per Cent

in Gernimative

Capacity.

95-75

93-5

910

86-25
81-25
6G-6

Total

Germination,

Per Cent.

98-6

97-5

•7-25

95-25

95-75

95-75

Owing to the similarity between the smut diseases of different plants,
the methods found efficacious for smut of cereals may be employed in
all cases.

Ustilago Patiici-miliacei, Wint. (smut of millet). — The treatment of
the grain by Kuhn's method, one hour's steeping in a blue vitriol
solution of 0-5 per cent, followed by a 6 per cent milk of lime, pre-
vents the infection of the young plaut (plantule) by spores adherent
to the seed. The same delay in germination was observed by Aderhold,
who also found that 86 per cent of the seeds treated germinated, show-,
ing 04 per cent of rust against 90 per cent of the untreated seed with
745 per cent of rust. It is an excellent palliative, but it is better
still to roast the spores by letting them fall through a twig bi oom held
1 metre above a very light straw fire.

Ustilago Maydis, Corda (smut of maize) cannot be avoided as surely
as all the other rusts, because the spores of this fungus are of them-
selves able to penetrate into the adult plant through the newly formed
leaf. In spite of this peculiarity blue vitriol is used with success, but
it does not prevent future infection of the plant.

Urocystis Cepuhe, Frost (smut of the onion). — Although the disease
may be suppressed by rejecting all rusty stocks on transplanti g, Mohr
points out the good effect of spraying with a 3 per cent solution of blue
vitriol.

Puccinia (rusts). — Three different species are found on grain
crops: Puccinia graminis, Pers. (common or linear rust); Puccinia
Bubigo-vera, Wint. (spotted mildew); Pitccinia coronata. Cord, (rust
of oats). — The development of rust differs totally from the method
of propagation of smut and bunt. It is impossible to prevent rust
of corn in the same way and at the same timy as smut diseases by
simple disinfection of the seed-corn. Their methods of multiplica-
tion are so varied that it is, so to speak, impossible to create an obstacle
to the propagation of these diseases by chemical means so as to hope
for a radical effect, curative or preventive, by the means which render
such excellent service in combating other diseases. The means of
action are very limited, and direct attack is impossible. It is only
from an instructive point of view that the results obtained by spraying
with blue vitriol preparations are given. Wuthrich has shown that the

224 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

uredospores, though much less resistant than the spores of most fungi,
are yet destroyed by a 0"124 per cent solution of blue vitriol ; their
sensitiveness to this salt begins at the dose of 0'00124: ; at 0'0124 per
cent germination is prevented. Hitchcock and Carleton found a O'l
per cent solution prevented their germination without killing the spores.
H. de Vilmorin and F. Douillet found that plants of white March
Chiddam wheat, treated several times with blue vitriol sprays and
afterwards conveyed close to mildewed wheat, were not attacked,
whilst in the same conditions untreated plants were invaded. But this
treatment, difficult even when the wheat is in the blade, becomes im-
practicable when it is in the ear. It is owing to this difficulty that
this process has miscarried, although it has been found efficient in ex-
periments on the large scale in Australia, and by Leon Noiret in the
Cote d'Or. The dose required to kill. uredospores is much greater than
to destroy the zoospores of mildew of the vine, and it is surprising
that spraying has such perfect results. In our opinion, blue vitriol
would act in this case more especially as a stimulant, producing more
active and vigorous growth, enabling the plant to oppose a greater
resistance to invasion by this fungus, and thus to acquire a sort of
immunity.

Helminthosporiwn granmieum, Eriks. (browning of barley). —
Kolpaon Raon insists that Kuhn's prooess is an excellent means of
preventing this disease.

ClavicejJs j^urpiirea (ergot). — The conidia of this fungus do not
develop in a solution of blue vitriol of 0"0124 per cent.

Dematoplwra necatrix (root rot of the vine). — Dufour recommends
blue vitriol to prevent this disease. When the roots are completely in-
vaded by the mycelium the plant is condemned, and ought to be de-
stroyed, the more so as the organs of propagation, the conidiophores,
charged with conidia, appear to develop, especially after the death of the
tree. By tearing up the tree and carefully exterminating the debris of
the roots and the ropes, the propagation of the disease is prevented.
To destroy the spores, or the mycelium, of which the soil may retain a
fraction, the latter is watered with a 3 per cent solution of blue vitriol.
Before planting new vines 1-2 litres of this same solution is poured
into the holes. Within a radius of 2-3 rows the stocks ah-eady
attacked or not are stripjjed in the spring and freely watered with
this solution ; 100-150 grammes of blue vitriol in powder may likewise
be spread per stock. The result is not always complete and visible the
first year, and it is sometimes necessary to repeat this treatment two
years running ; the results obtained in these conditions are, however,
very positive.

Guignardia Bidwellia, Viala et Eavaz (black rot of the vine). —
From the first apjjcarance of this disease, when it was found that it
did not apjjeai- at lirst on the fruit but only the leaves, which then
became hotbeds of infection for the gra})es, attempts were made to
stop its evolution by repeated sprayings of blue vitriol. The experi-
ments made at Ganges were not very satisfactory, whilst bouillie
bordelaise later on gave the most perfect results. Eathey and Havelka.
have proved that the spores are killed after thirty hours' steeping in a.

COPPER SULPHATE (BLUE VITRIOL). 225

blue vitriol solution of 0'5 per cent, and they recommend the disinfec-
tion of the buds of the vine against black rot by total or partial
immersion in a 1 per cent solution for one hour. Their experiments
succeeded perfectly, and proved also that the steeping of the buds for"
an hour in 1 per cent, 5 per cent, and even 10 per cent solutions of
blue vitriol, did not lower their vitality ; the lower section seems as if
it could no longer form a cushion to remedy this drawback : it suffices
to cut I of an inch below the buds before transplanting them.

Gloeosporium ampelophaguvi, Sacc. (grape rot). — Sorauer recom-
mends blue vitriol in place of green vitriol to combat this fungus in
winter. Instead of coating the stock with a 50 per cent solution of
green vitriol a 20 per cent solution of blue vitriol is used. This
practice is excellent, but more costly than Slavinsky's.

Gloeosporium nervisequum, Sacc. (disease of the leaves of the
plane-tree). — Nobele recommends, to prevent this disease, to spray
with a 3 per cent solution of blue vitriol in the month of April and in
the month of May before the tree is in leaf.

Fusicladmm pirinum, Fuckel (pear scab) ; Fusicladium dentri-
ticum, Fuckel (apple scab). — These diseases may be combated by
spraying with blue vitriol solutions. By judicious spraying at the
right moment the conidia formed on the cushion of the conidiophores
of the leaf are destroyed, and prevented from planting themselves
on the fruits. Oliver found that the spores were destroyed by blue
vitriol. Used on large scale in 0"5 per cent solution by Goif, he
greatly diminished these diseases. Mohr recommends a 3 per cent
solution for the same purpose. These sprayings should be done
before spring, in the month of April. Blue vitriol has not such a
radical action as bouillie bordelaise. The latter may, if used before
the expansion of the buds, completely prevent these diseases.

Morthiera Mespili, Fuckel ; Entotnosj)orium, macidatum, Lev. (leaf
scald). — This disease of the leaves of the pear may be prevented,
according to Mohr, by spraying with a 3 per cent solution of blue vitriol
before the formation of the leaf in April and May.

Disease of the Poppy (oeillet). — Mangin advises to prevent this
disease to steep the buds in a 0-1-2 per cent solution of blue vitriol
before transplanting.

Beet Diseases. — To prevent these diseases, transmitted by spores
infecting the seed, disinfect the seed with blue vitriol, which gives good
results against —

Pleospora putrefaciens, Franck (rot of the heart of the beet) and
Phoma tahifica, Prill, et Dell. [Phoma Betce, Franck), (disease of the
leaf-stalk of the beet). — Carlson advises washing the seed in a 1-2
per cent solution of blue vitriol. Linhart advises steeping for twenty-
four hours in a 2 per cent solution ; although this diminishes the
germination of the seed a little, yet Franck recommends it. It also re-
moves the larvae of Agriotes lineatus, Hypoviyces magnus (mole disease
of the mushroom). It requires three to seven days' steeping in a
2 per cent blue vitriol solution to kill the spores. This disease is not
circumscribed by this salt.

Black Disease of the Clematis. — To prevent this disease produced

15

226 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

by a slug, copious spraying with solutions of blue vitriol every fort-
night before transplanting have a good effect.

Use of Blue Vitriol against Worms and Snails. — Snails and
slugs are as sensitive to blue vitriol as to green vitriol. If they pass
over a surface sprayed with blue vitriol they soon die. The hatred of
snails for blue vitriol is such that to remove them it suffices to stretch
a cord, 1^ inches wide, steeped for twenty-four hours in a 10 per
cent solution. This cord ought to touch the soil ; it forms an in-
surmountable barrier. This method is practised in Italy. Bignon
has also observed that the vitriolizing of ropes and trelUses remove
slugs.

CHAPTEE XIV.

COPPER HYDRATE— BOUILLIE BORDELAISE— BOUILLIE
BOURGUIGNONNE.

91. Copper Hydrate (Bouillie Bordelaise), — Preparation. —

By precipitating a soluble salt of copper, by caustic alkali, or by milk
of lime.

CuSO, + 2NaOH = Cu(OH), + Na.SO,

Copper Sodic Cupric " Sodic

sulphate. hydrate. hydrate. sulphate.

CuSO, + Ca(OH), = Cu(OH,) + CaSO,

Copper Calcium Copper Calcium

sulphate. hydrate. hydrate. sulphate.

The bouillie bordelaise is prepared by the second reaction; it is
a mixture of hydrated oxide of copper and sulphate of lime, and gener-
ally contains an excess of lime. Its composition and its concentration
vary much.

Preparation of a Normal Bouillie Bordelaise. — A solution of
blue vitriol is prepared on the one hand, and on the other hand a milk
of lime carefully rubbed up with water.

1. Blue Vitriol. — This salt should be as pure as possible. It
should be dissolved in wooden, copper, glass, or stoneware vessels;
those of tin and iron should be avoided, as these metals decompose
blue vitriol. To facilitate solution of blue vitriol it is placed in a basket
or pocket of wire gauze, in a vessel filled with rain water, so that it
dips into it completely, but as near the surface of the liquid as possible.
Solution is complete in twelve hours. If pressed for time blue vitriol
may be dissolved in a little warm water and this solution run into the
receiver containing the remainder of the water required to make the
bouillie. It is necessary to use a cold solution of blue vitriol in making
the mixture, for with hot solutions there would be formed, along with
the granular hydrated oxide of copper, some inert black oxide of
copper.

2. Milk of Lime. — The lime should be fat lime in lump. This
quicklime is slaked by adding water gradually. As soon as it is slaked
lit is beaten up in cold water to form milk of lime. This milk of lime
is passed through a fine sieve, to separate the impurities present in all
limes. To obtain a fine, gelatinous, homogeneous precipitate, having
a maximum adherence to the leaves it is advisable to mix these two
liquids as follows : The milk of lime is run slowly, in a fine stream,
into a cold solution of blue vitriol, stu-riug constantly, or better still,
run the two solutions simultaneously and slowly into a third vessel

(227)

228 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Stirring the latter energetically. Theoretically 14 lb. of pure quick-
lime suffice to precipitate 62^ lb. of pure blue vitriol. Practically the
amount of lime used is always greater, because the lime is never pure.
The amount of lime varies, therefore, according to its purity, from 1-3
lb. of lime to 3 lb. of blue vitriol. The most advisable quantities ta
form an active bouillie are 10 lb. of blue vitriol in 50 gallons of water,
and 3^-10 lb. of lime, dissolved in 50 gallons of water. The mixture
formed by these two solutions is termed a 1 per cent solution.

Properties of Copper Hydrate. — Copper hydrate is a pale blue
precipitate, which is more fine and gelatinous the lower the temperature
at which it is precipitated. It is almost insoluble in water at all
temperatures ; it is converted in hot water into black copper oxide, CuO.
It is, however, soluble in mineral and organic acids.

Properties of Bouillies Bordelaises. — A bouillie bordelaise,
prepared in good condition, should have the following properties :
It should be neutral or slightly alkaline ; it must never contain an
excess of blue vitriol. To ascertain its composition a little of the
bouillie is filtered, or allowed to settle. The limpid liquid collected
should not be tinted blue (which would point to unchanged blue
vitriol), but should be absolutely colourless. It should give no reaction
with litmus paper, nor an alkaline reaction with turmeric paper.
Another and still better method of showing the presence of small
quantities of undecomposed blue vitriol consists in placing a little
bouillie bordelaise in a saucer and to pour on it a few drops of yellow
prussiate. The presence of blue vitriol is revealed by a red coloration
of the bouillie. A blade of a knife dipped in a bouillie, still containing
blue vitriol, is covered with a deposit of metallic copper.

The bottillie must be tested and respond to the tests in the right
tvay, otherioise it is unfit for all the purposes for which it is intended.

Too oftea the sprayings eventually burn the leaves and the young
parts of the plant. They are due, with few exceptions, to faults in
the composition of the bouillie. Traces of blue vitriol, not converted
into cupric hydrate, suffice to cause these burns. As a preventive of
cryptogamic diseases the bouillie must be as adherent as possible, so
as to prolong its action on the surface of the vulnerable organs of the
plant.

Adhesion depends on several factors: (1) The blue vitriol should
be precipitated cold, as above described, by milk of lime. (2) The
more pure (fatty) the lime, the more adherent the bouillie. (3) The
more freshly prepared, the more adherent the bouillie. (4) The bouillie
is the more adherent the moi'e nearly neutral it is ; that is, without an
excess of lime. Although it is not injurious to vegetation, it is well'
to estimate exactly the quantity of lime to use in preparing the bouillie^
Lime in excess has, moreover, the drawback of retai'ding the action of the
bouillie bordelaise on the germs of cryptogamic fungi. Cupric hydrate
as deposited on the leaf of a plant is, so to speak, insoluble, and thus,
inert towards the spores in contact with it. To become active it must.
be converted, in contact (1) with the air, into copper carbonate, soluble
at the rate of 40 milligrammes in a litre of water containing carbonic
acid ; or (2) with carbonate of ammonia, or be dissolved by the juice

BOUILLIE BORDELAISE. 229

exuded on the surface of the leaves. Whichever of the two cases
occurs, or both together, it will be seen that cupric hydrate mixed with
a large excess of lime will not have such a rapid action as in the
absence of lime, the latter having a great affinity for carbonic acid".
It also neutralizes organic acids, and in many cases, as the action of
the bouillie bordelaise cannot be retarded, to stop infection an excess
of lime should be avoided. An excess of lime delays the action of
bouillie bordelaise one to ten days, according to the amount of lime
used. Bouillie bordelaise, when well prepared, combines all the pro-
perties required in an anticryptogamic bouillie, and all the substances
added to increase its toxic action on spores or adherence to the leaves
are useless if it be conscientiously prepared and used immediately
afterwards. To popularize its use the trade has prepared powders,
having exactly the composition of a normal bouillie, which only require
mixing with water to produce a bouillie bordelaise. The greater
number of these pow-ders yield bad bouillies ; they may undergo de-
■compositions, rendering them unfit for the pr-eparation of a proper
bouillie, and yield heterogeneous bouillies, in which undissolved blue
vitriol is plastered up with a layer of sulphate of lime. Not only does
it become difficult to use them with the spraying machine, but they
have all the defects of badly made bouillies. If applied by the bellows
the same thing occurs on the leaf, the chemical reaction is incomplete,
the blue vitriol acts as such and causes burns. Nothing, therefore, can
replace a bouillie made on the spot by one's self, with the precautions
indicated above, and no similar preparation can be either so adherent
or so efficient.

Action of Cupric Hydrate on Plants. — Insoluble copper salts
appear to be absorbed to as great an extent by the roots as by the aerial
organs of the plant, and cause poisoning. If the doses absorbed are in-
finitesimal no poisoning occurs. The copper salts then exert a salutary
stimulating effect. It was thus essential to find a salt of copper which in
contact w^ith plants was only absorbed in infinitesimal doses, simultane-
ously stimulating the growth of the plant and destroying cryptogamic
disease. It was found that cupric hydrate fulfilled these conditions
best and that bouillie bordelaise could practically fill that role. The
cupric hydrate deposit formed on the leaves is very adherent, insoluble
in water, and barely soluble in water containing dissolved carbonic
acid or carbonate of ammonia. It lets the plant absorb it in infinitesi-
mally small doses, which might escape detection in analysis, but which
none the less exist since their presence in the leaf renders it so far
immune to cryptogamic diseases, and especially vigorous analogous to
the condition realized by spraying the soil with blue vitriol. Leaves
of the potato plant treated with bouillie bordelaise become thicker and
more vigorous, the chlorophyll increases, assimilation is more active,
and the starch content of the tubers greater (Frank and Kruger).
Galloway got the same results with fruit trees. Young plants sprayed
three to four times a year showed much more rapid growth, and pre-
served their leaves into the winter. It is very evident since this cupric
treatment gives to the leaf a great assimilative force, and that it pro-
longs this into the winter, the young tree will have grown more rapidly

230 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

than trees which prematurely shed their leaves by degeneration induced
by parasites. Numerous comparative trials have shown in an irrefu-
table manner, that young fruit trees in the nursery, treated with four to-
seven sprayings with a 2 per cent bouillie bordelaise, show an increased
height, and yield crops largely compensating for the cost of this treat-
ment. In nurseries young pears treated three years in succession
attained a height of 5 feet to over 7 feet, and had a diameter of 7-^
inches, whilst untreated pear-trees of the same age, placed in the same
conditions, only reached 2-3 feet in height and only 2^-S^ inches in
diameter. If the market value of young pear and cherry trees, treated
together for three years, be compared with similar untreated trees,
there is a gain after deduction of all the cost of treatment of 52 shillings
per 1000 trees. With young pear-trees the experiments were not sO'
decisive, as their leaves are often sensitive to bouillie bordelaise. The
same observations have been made as regards the vine. To obtain a
richer growth large doses of copper are not necessary. It is now
believed that 0'25 per cent, and even 0"1 per cent, do the same good
as 1 per cent bouillies. Bessler, by one spraying of bouillie bordelaise
on haricots when tilling the ground, followed by one spraying of the
young plant, obtained a 50 per cent better crop than on untreated
plants. It is only the stimulating and preventive treatment which
gives this result.

We must not wait until plants show signs of cryptogamic diseases
before treating them, but prevent such by destroying the germs.
Some plants, however, do not stand the deposition of hydrated oxide
of copper on their leaves without injury, because, owing to the ex-
ceptional nature of the foliageous tissue, it is absorbed in too great
quantity, and then acts like blue vitriol. The plants which behave
thus are apple-trees, peach-trees (Sturgis, Milller, Thiel), and some
varieties of rose bushes. On these trees the treatment is followed by
the fall of all the leaves reached by the bouillie bordelaise, or at least
by burns which cause holes in the leaves. Miiller and other observers
found that these burns especially occur when the plant is exposed to
the sun, and that plants in the shade do not show these injuries.
Amongst apple-trees the most sensitive are Canada Cordon, Bellefleur
jaune, Eibstone pippin, Danziger Kantapfel. On these species the
leaves appear riddled with holes after treatment. Trials, to see if
lime contributed to the injurious action of the bouillie bordelaise, have
shown the contrary. Whilst a 4 per cent milk of lime has no injurious
action on bouillie bordelaise, a 0-5 per cent solution of blue vitriol and
a 1 per cent milk- of lime burnt the leaves as much, and even more,
than a bouillie with 4 per cent of lime and -05 per cent of blue vitriol.
The peach-tree — the most sensitive to bouillie bordelaise — behaves to-
wards it as towards pure blue vitriol. The treatment is followed in most
cases by the fall of the leaf ; but after this treatment the peach,
nevertheless, shows the same recfudescence in its vitality as soon as
the new leaves come fortb, so that in the end this treatment is as
salutary as for other trees. The action of cupric hydrate is thus ana-
logous to that of green vitriol ; in a general way this salt increases the
chlorophyll, and consequently the assimilation ; it thus prolongs the

BOUILLIE BORDELAISE. 231

vitality of the deciduous organs of the plant. Green vitriol, heing
present in commercial blue vitriol to at least 2 per cent as an impurity,
it was imagined, first in America, then in Germany, that the strengthen-
ing effect produced by the bouillie was only due to this green vitriol,
for which reason Aderhold advised the use of a bouillie bordelaise of
the following composition : Blue vitriol 1-9 per cent, green vitriol
0"1 per cent, lime 2 per cent. Guocdenovic, who examined these
bouillies, found that they had not any greater stimulating action than
an ordinary bouillie of 2 per cent blue vitriol and 2 per cent lime.
The dose of green vitriol, required to produce an analogous physio-
logical effect to that produced by spraying with bouillie bordelaise is
0*5 per cent. The plant must also come in contact with the soluble
salt, the green vitriol, the hydrated oxide of iron deposited on the
leaves having produced no result, except as a 3 per cent bouillie. A
bouillie containing O'l per cent of green vitriol in an insoluble form,
cannot therefore act on the plant and sti"engthen the action of the
bouillie bordelaise, far less the impurities, which only bring 0'04 per
cent of hydrat:d oxide of k'on in contact with the leaves. It must
therefore be admitted that blue vitriol acts in the same way as green
vitriol, but it is about ten times more active in much smaller doses.
Then comes the problem of the absorption of the copper by the leaves
when this product is deposited thereon in an insoluble form. Although
the increase of the chlorophyll may be easily determined, although
the action of the copper on the plant be undeniable, it is very difficult
to find in the leaf, in consequence of this treatment, abnormal quantities
of copper. It is thus owing to imperfections in our methods of an-
alysis that it is generally believed that copper is not absorbed by the
leaf. Sestini has, however, found more than normal amounts of
copper in \'itriolized vines. Analyses of this sort are very difficult
and very delicate to make, for many reagents, even distilled water
itself, may contain the infinitesimal doses of copper sought for in the
plants. Nageli, from experiments he made on the alga spirogyi'a,
concluded that a plant which did not show any symptom of poison-
ing could not have absorbed copper, as the latter, absorbed by a
cell, kills it, and since the favourable action of copper is undeni-
able, it must act at a distance. These conclusions raise hypothetical
questions which we cannot discuss. It will be sufficient to point
out some facts which plead in favour of absorption, and which show
that the plant is perfectly capable of dissolving insoluble copper
derivatives deposited on the surface of the leaves, and of absorbing
them in minimum quantity. Barth was the first to express the
opinion, so disputed by Droop and Wortmann, that cupric hydrate
is dissolved by the exudations of the leaf. Clark has given consider-
able support to this hypothesis. Having observed that animal and
vegetable substances were capable of dissolving cupric hydrate, an ob-
servation which Swingle had already made as regards the secretions
of certain fungi, he concluded that certain organic compounds con-
tained in the juice of plants may dissolve cupric hydrate. To verify
this hypothesis he wrought on the leaves of the peach-tree, which are
the most ready to absorb copper. In fact, these leaves covered with

232 INSECTICIDES, FUNGICIDES, AND WEED KILLERS,

a layer of bouillie bordelaise, give up to the water lying on them for
some time a quantity of dissolved copper capable of killing the spores
of fungi. When there is dew on a leaf, two liquids, separated by a
membrane, are present, the one is charged with soluble bodies, while
the other is pure water. It follows that exosmosis of the leaf may oc-
cur towards the dew. The ox'ganic substances thus in contact with the
deposit of cupric hydrate may dissolve not only the quantities required
to kill the germs fallen on the leaves, but also those indispensable to
the plant itself. Thus the dose of soluble copper collected in this way
by Clark killed the spirogyra. The water thus contained more than
O'OOOOOl per cent, an amount perfectly sufficient to stimulate the
plant. From the deadly effect of blue vitriol on the cells of plants,
and the difficulty with which this salt is absorbed, it does not neces-
sarily follow that the insoluble salts deposited on the plant behave in
the same way. Those which are insoluble and neutral would have
no action on the plant, nor on the spores of fungi, if they were not
rendered soluble and assimilable by conversion into a soluble organic salt,
which may be absorbed by the leaf and destroy the spores on the surface
of the organs of plants. The amounts of soluble copper salts required
to stimulate the plant are so small, and those which suffice to preserve
it from invasion, by injurious fungi, are so infinitesimal, that their
presence in the organs of the plant which have been in contact with
the copper cannot be chemically demonstrated ; but the principle of
absorption cannot be denied, since the constant presence of copper
in the ashes of the plants treated has been determined by analysis.

Action of the Bouillie Bordelaise on Fresh=water Algae. —
Green algae behave towards copper like all green plants, but they are
much more sensitive to its action, probably because ia the experiments
all the body of the plant dips into the poisonous solution. This plant
is perfect for allowing the observer to follow progi-essively the action
of blue vitriol on the living cell. Nageli examined and determined
the precise action of blue vitriol on spirogyra. It was desired to de-
termine, likewise, how this alga behaves towards bouillie bordelaise.
Rumm undertook this work and examined separately the action of
the different ingredients composing bouillie bordelaise on the alga
Spirorji/ra longata. Sulphate of lime had no action. Calcium hydrate
is absorbed, beginning with a strength 1 in 3750 and then acts in an
injurious manner. Cupric hydrate is not soluble enough in water to
cede to it an amount of copper capable of preventing the growth of
the alga. On the other hand, the contact of cupric hydrate with the
alga kills it, owing to evident and visible absorption of copper. The
chlorophyll bands are torn, the plasma contracted, and the colour of
the contents browned. Rumm explains this fact by the secretions of
the alga dissolving the cupric hydrate, and the soluble derivatives ab-
sorbed by it of a certain strength kill it. He observed, however, that
this action was more dilatory the more lime the bouillie bordelaise
contained. In ])resence of a large excess of lime the action became
nil. The bouillie bordelaise acts therefore on alguc containing chloro-
phyll as on othei' green j^lants.

Action of [3i)uillie Bordelaise on Fungi. — Cupric hydrate is

BOUILLIE BORDELAISE. 233

not soluble enough in water to prevent the germination of the spores
most sensitive to copper salts, even after prolonged treatment with
them (Aderhold and Eumm). To understand the action of bouillie
bordelaise, it is, however, necessary to admit that there is a partial
solution of oxide in the water deposited on the plant owing to the con-
tact of this oxide with the active organs of the latter. Clark, in ex-
amining the poisonous capacity of the most diverse derivatives of copper
on fungi cultivated in a nutritive liquid, beet extract, observed that this
liquid dissolved cupric hydrate. Examining afterwards other substances
of vegetable origin, he found they had the same property. This led
him to believe that hydrated oxide of copper insoluble in water is much
less so in presence of special organic substances. Swingle had already
shown that the secretions of certain fungi dissolve cupric hydi-ate.
Clark found afterwards that extracts of Psaliote campestris, as well as
infusions of different parasitic fungi, dissolve this oxide of copper in
sufficient quantity to prevent the germination of their spores. The
nature even of the fungi would thus contribute to dissolve the amount
of cupric hydrate required to prevent the development of the spores.
The rapidity with which the spores are destroyed depends on the
thickness of the exospore. On the other hand, Sorauer believes that
the spore is never killed by the presence of cupric hydrate in the
drop of water in the midst of which it is develoj)ed, but that, on the
other hand, this copper derivative, by weakening it, prevents the ger-
mination tube from penetrating into the nurse plant. Hence, spraying
with bouillie bordelaise on a plant invaded by a fungus is never cap-
able of destroying the mycelium of this fungus developed in the
interior of the plant. It cannot even prevent the latter from fructify-
ing normally, and spreading around it spores to propagate the disease.
The sole object of spraying with bouillie bordelaise is to prevent the
penetration of these spores into healthy unattacked plants or their
■organs. When spraying is done in the right conditions, the bouillie
bordelaise covers all the vulnerable surface of the plant with a layer
of cupric hydrate. This layer forms a fixed and adherent reserve of
a poison of which an infinitesimal quantity dissolved by the juices of
the leaf stops the normal evolution of the spore fallen on a drop of
(dew. At the same time the very small quantities which penetrate
into the plant, impart to it greater vigour which enables it to become
to a certain extent immune to the disease.

Use of Bouillie Bordelaise. — History. — It was found by a chance
observation, that a mixture of lime and copper might be useful in the
struggle against cryptogamic diseases. To prevent marauders from
gathering the ripe grapes on vines along the roads it was customary,
long before the appearance of mildew, in the different communes of
Burgundy to spray the grapes with milk of lime, to which was added
a little blue vitriol to blue it. They treated five to six stocks in the
border in this way. Now, as far back as 1882 it was found that these
borders were less subject to mildew than the rest of the vineyard, and
when the disease assumed extensive and intensive proportions, as was
the case in 1884, round about St. Julian, this border bespattered by
milk of lime, blued by blue vitriol, appeared quite detached from the

234 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

rest by the verdure of the leaves, and by the perfect health of the-
grapes. Owing to experiments made by Millardet and Jouet, it was-
found that this fortunate action was to be attributed to the copper and
not to its lime. This empirical remedy was thus recommended to com-
bat mildew, under the name of bouillie bordelaise. In the beginning;
the bouillie bordelaise was much stronger than now. It consisted of
15 per cent of lime and 8 per cent of blue vitriol. This bouillie was
spread on the vine by means of small heather brooms, for its consist-
ency did not allow the use of a spraying machine. From year to-
year the dose of blue vitriol was diminished, and the lime, an excess-
of which was found useless, was reduced to the dose strictly necessary.-
In 1887 bouillie bordelaise consisted of 3 per cent of blue vitriol and 1
per cent of quicklime. Millardet and Gayon had already experimented
at this time with weaker bouillies, with 2 per cent, and even 1 per
cent of blue vitriol. As these bouillies produced the same effect, they
regarded them as efficient and recommended several sprayings with a
1 per cent bouillie in preference to a single spraying with a 3 per cent
bouillie of blue vitriol. These results were published in 1888, andi
spread the formula of the new bouillie over the whole world, where it
was adopted as the normal bouillie. Owing to a great increase in the
price of blue vitriol it was tried to reduce the amount of blue vitriol
entering into the bouillie. Guocdenovic has shown that a 0'5 per
cent bouillie suffices in all cases. Zweifler extended his experiments-
from 2 per cent to O'l per cent bouillie, and concluded that 0'5 per
cent of blue vitriol was sufficient — an efficient bouillie against mildew^
These proportions are used on the large scale and with great success
in Italy and the Tyrol. Used at first exclusively against mildew it
has been found that bouillie bordelaise is perfectly capable of combat-
ing a great number of other diseases.

Practical Spraying. — -The less cupric hydrate in the bouillie the
greater must be the number of sprayings. Eepeated spraying against
plant diseases is in general favourable, because only the organs of the
plant reached are rendered invulnerable, so far as wind and rain have-
not removed the preservative layer of copper oxide. To preserve a
plant for the whole year from disease, the growth of the spores of
parasitic fungi must be stopped. As there is a continual growth of
new leaves uncovered by bouillie bordelaise, several sprayings must be
applied preferably during fructification of the fungi, and especially
during the germination of their spores. To prevent plant disease by
bouillie bordelaise it is necessary —

1. That the bouillie be made conscientiously according to the pre-
ceeding rules. Bouillie bordelaise is mostly used neutral. However,
numerous experiments by Mader, Bain, Sturgis, and Aderhold have
shown that in certain special cases it is better to use bouillies containing^
an excess of lime. Certain fruit trees, sensitive to neutral bouillie
bordelaise as much as to pure blue vitriol, are so no longer when there
is excess of lime. Against the cryptogam ic diseases of the apple and
peach trees, it is well to use 0"/5 per cent of blue vitriol and 4 per cent
of quicklime.

2. That the evolution of the disease to be fought against b&

BOUILLIE BORDELAISE.

235

Fig. 8. — Eclair Sprayer.

Fig. 10. — Eclair Sprayer, No. 1 bis.

Fig. 11. — Eclair Sprayer Supra.

BOUILLIE BORDELAISE.

23T

I

perfectly known, so as to be able to treat it at the moment of the dis-
semination of the disease, and prevent in time its establishment in the
plant ; a slight delay in the use of the remedy may lead to complete
failure, for it is asserted by Prillieux that spraying after the penetratioa .
of the spores of the fungi into the interior of the tissue of the plant in-
no way prevent its normal evolution and fructification. If a greai>
number of fungi may thus be combated by a neutral well-made bouillie,
with O'o-l'O per cent of blue vitriol, the application of the remedy must
vary with the method of propagation and evolution of the fungus. If
these rules are observed bouillie bordelaise gives perfect results in all'
cases quoted farther on. Hence there is annexed to this treatise a
brief sketch of the evolution and manner of life of the chief parasitic-
fungi, so that the amateur little versed in these questions may find both
the remedy and the best time to use it.

Use against Mosses and Lichens. — Although cupric hydrate has-
not the solubility of blue vitriol its regular use on the trunks of trees,
helps to lessen these parasites and eventually cause them to disappear.
Waite, Schoyen, Hume, and Leroux advise for this purpose a 3 per
cent bouillie bordelaise applied on the trunks after cleaning with a.
scraper.

Use against Bacterian Diseases of Plants. — Amongst the ever-
increasing number of plant diseases attributable to bacteria some may
be combated with bouillie bordelaise.

Potato Scab. — Bolley, who discovered the cause of the scab, foundi
that disinfection of the tubers with 2 per cent bouillie bordelaise was
capable of preventing the growth of this disease. He got the following;
result : —

TABLE XKXYII.—Shoivmg Effect of 2 Per Ceiit Bouillie Bordelaise in Pre-
venting Potato Scab.

Tubers.

DiLration
of Stee]}.

Sound

Tubers,

Per Cent.

Untreated
Treated

J hour
3 hours

1

57
53

Longer steeping of the seed in bouillie bordelaise does not injure the*
seed if it has not sprouted.

Bacterian Disease of the Wild Quince-tree. — This disease known in
America has been successfully treated with bouillie bordelaise.

Use against Parasitic Myxomycetes. — Plasmodiojjhora cali-
fornica, Viala and Sauvageau (browning of the vine or the Californian
disease). — This disease cannot be treated with bouillie bordelaise
(Sorauer).

Use against Parasitic Fungi. — Peronosporce. — The eighty knowa
species, each more formidable than the other, have the same evolutiorn

238 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

and the same method of dissemination. They may be treated with
bouilHe bordelaise.

Phytophthora infestans, De By. (potato disease). — To avoid the
phytophthora sound tubers which do not bring the first germs into
the field must be planted in the first instance, and secondly sprayed
•on the stems to prevent the propagation of the disease by plants ac-
cidentally attacked.

Treating- the Tubers. — Beyond scrupulous sorting disinfection
may be of great service. Of all the treatments recommended, that of
bouillie bordelaise is the most energetic and the most certain. The
tubers are steeped in a 2 per cent bouillie bordelaise ; 10 gallons of
bouillie suffice for 100 lb. of tubers. The duration of the steep is
twenty-four hours, after which the tubers are steeped for twenty-four
hours in pure water, then they are dried in the open air. The treat-
ment should be carried out five to six weeks before planting. The dis-
infection has no objectionable effect on the germinative capacity of the
tuber if the process be conducted as recommended by Frank. Godefroy
found no alteration even after several days' steeping in the bouillie.
Frank and Kruger found the treatment, on the contrary, favourable to
the future evolution of the potato ; it springs up quicker and yields a
more vigorous plant and also a greater number of tubers in the ratio
of 3 to 2. The good effects of the bouillie on the germinative capa-
city are not felt, except on condition that the tuber has no forward
sprouts at the time of treatment, for the bouillie is very injurious to
them. That is the reason why it is essential to disinfect potatoes
sometime before planting them, when they have not yet sprouted.

Treatment of the Stems. — So long as treatment by the bouillie
bordelaise was limited to the aerial part of the plant the results were
not always favourable, especially as regards the yield in tubers, and
•opinions as to the efficiency of the treatment were divided. In fact it
will be seen that where the phytophthora has deeply invaded the tissue
of the tubers a treatment of the stems with bouillie bordelaise can pre-
vent the evolution underground of the disease, and that failure is
inevitable in such conditions. If all underground evolution is, on the
other hand, prevented by a rational treatment of the seed potatoes, the
effects of the aerial treatment will not fail to give satisfaction. It is
not, therefore, surprising that certain experimenters have obtained, in
some cases, a considerably diminished jneld. Lieber found 20 per
cent and Brunner 47 '5 per cent, and that this treatment, which was
first tried by Jouet in 1885, did not become general so rapidly as that
for the mildew of the vine. However, Fasquelle's trials in 1886,
Prillieux's in 1888, and Girard's in 1890, showed that a scientific ap-
plication of bouillie bordelaise killed the phytophthora without injuring
the plant. The diminution in the number of tubeis, and in the
starch which they contain, seems due to the poisoning of the leaves
by imperfect liouillie, inducing a degenei'ation of the leaves, which
renders them less fit for assimilation (Sorauer). The bouillies used
at first contained too much copper and caused burns. Sempotovsky
threw light on this point by showing that the weaker the bouillie
the more active it is.

BOUILLIE BORDELAISE.

239

TABLE XXXVIII. — Showing Effect of Bouillie Bordelaise of Various Strengths
on Weight and Starch Content of Potato Crop and Per Cent of Diseased
Potatoes.

Diseased

Bouillie
Bordelaise,

Weight of
Crop Per

Starch,

Diseased

Tubers,

Per Cent,

Plants.

Strength,

Acre in

Per Ce7it.

Per Cent.

Tons Metric.

Untreated

10-28

19-1

6

Treated

6

11-2

18-0

2-8

Untreated

—

10-48

19-6

5-2

Treated

8

8-52

18-1

3

Untreated

—

10-4

19

4-0

Two treatments

One 4, other 6

8-84

19-4

2

Untreated

—

9-9

18-01
(3928 lb.)

15-5

Treated

2

9-96

19-28
(4405)

1-5

The number of sprayings in the year thus has a great effect on
the efficiency of the treatment. Thienpont showed that the effects
obtained by several sprayings are always superior to those obtained by
a single spraying. Laplae, in this connexion, got the following
results : —

TABLE XXXIX. — Shoiving Beneficial Effect of Repeated Sprayuig zvith Copper
Bouillies on Potatoes.

Diseased plants untreated 10-44 metric tons per acre.
,, 1 spraying 10-88 „ „

„ 2 sprayings 11-94 ,, „

„ 3 sprayings 12-88 „ ,,

As to the weight of the crop, a great number of trials have proven the
efficiency of the bouillie bordelaise. Prillieux obtained with nine
plants : —

TABLE XL. — Showing the Effect of Bouillie Bordelaise on the Potato Disease.

Diseased
Plants.

Number
of Tubers.

Diseased
Tubers.

Treated
Untreated

115

80

9
26

Steglich tried this treatment on six different species, planted in plots
of 50 square metres, and in all cases obtained yields of from 10-80 per
cent higher than that of the untreated plot. The treatment consisted
in three sprayings : on 12 June, 17 July, and 15 August. Andra,

240 INSECTICIDES, FUNGICIDES, AND WEED KILLERS,

working on a field of 0-428 hectare, about 1-06 acres, obtained with one
spraying : —

TABLE XLl.— Showing the Effect of One Spraying of Bouillie Bordelaise o?c
the Weight of the Croj) of Magnum Bonum Potatoes.

S]}ecies.

Plants.

Tubers,
Lb.

Magnum bonum

Untreated
Treated

7750
10100

The cost of the treatment came to 3s. per acre, and the net profit to
57s. per acre. Mark, who experimented on fifty varieties, got an in-
creased weight of crop of from 30-50 per cent. Stroebel found a
higher yield of 48-7 per cent, and only 0-28 per cent of diseased tubers,
against 5-8-23-3 per cent in the untreated field. Honeyball found
a greater yield of 7-30 per cent. Finally in America and Switzerland
the same effects have been realized, and this treatment is applied on
the large scale in these countries as well as in France, in the whole
valley of the Garonne, where it gives full satisfaction. Doubts as ta
the efficiency of the treatment of the phytophthora by the bouillie
bordelaise are now no longer permissible; too many experiments show
that applied at the moment of the evolution of the disease, it com-
pletely prevents it from spreading, thus preserving the crop so greatly
compromised when the disease spreads normally. It is recommended
not to apply the first spraying except at the moment when the first
spots of the disease appear on the leaves. But it is better to make
a first preventive spraying. The number of sprayings to be practised
during the year is only regulated by the prevailing weather. If the
year be moist and warm, conditions essentially favourable to its-
evolution and to very rapid spreading of the disease, it will be well to
make several sprayings, only eight to fifteen days apart. During dry
periods spraying is useless, and m the case of a very dry year, during
which the disease does not assume a disquieting extension, a single
preventive spraying may be regarded as sufficient. Scientists do not
agree as to whether spraying is beneficial when the disease is not to
be feared. Sorauer, an advocate of spraying at the time of the appear-
ance of the diseases, has shown that if the infected fields treated in
time yield a much greater number of tubers than untreated fields, it
is no longer so when a field which is neither threatened nor invaded
by the disease is treated. Sorauer experimented on perfectly sound
tubers, which gave, before the appearance of the disease, a crop
absolutely exempt from diseased tubers, whilst these same plants
yielded, after the evolution of the disease, 59'4 per cent of diseased
tubers. These experimental fields gave before and after treatment : — ^

' Part of the potatocH of both plots were lifted before the disease appeared.

BOUILLIE BOEDELAISE.

241

TABLE XLII. — Sound Plants, Shoiving Number, Weight, and Size of Large
and Small Potatoes before the Axjpearance of Disease.

Plants.

Large

Tubers.

Small Tubers.

Number.

Weight.

Number.

Weight.

Treated
Untreated

28
38

843
1337

102
43

752
423

TABLE XLIII. — Diseased Plants, Showing Number^ Weight, and Size of Large
and Small Potatoes after the Appearance of the Disease.

Pla?its.

Large Tubers.

Small

Tubers.

Nu7nber.

Weight.

Number.

Weight.

Treated
Untreated

45
33

1450-8
1191

92
91

810-8
1191

According to this table the untreated sound plants, i.e. the tubers
of which were lifted before the disease appeared, gave a greater yield
of tubers than those treated with bouillie bordelaise. Sorauer explains
this fact by a certain degeneration of the leaf, very characteristic,
which is the result of treatment with cupric compounds. This-
degeneration is especially pronounced when the bouillie used still
contains unconverted blue vitriol, or when sprayings are made with
a soluble salt such as acetate of copper. Sturgis got the following
results with various copper preparations : —

TABLE XLIV. — Shoiving the Effect of Various Copper Preparations on the
Bulk of the Potato Crop, and the Number of Diseased Potatoes.

Per Cent.

1

1

0-1

0-5

0-1

0-15

0-06

0-125

0-250

Blue vitriol ^
Lime j-

Emerald green J
Blue vitriol \
Lime /

Copper acetate \
Emerald green J
Blue vitriol )

Ammonium carbonate j

Bushels
Per Acre.

286

269-5

181-5
156

Diseased
Ttll)ers.

Sorauer advises not to spray early varieties, generally lifted before
the disease develops in a threatening manner, for the treatment would
not only be useless, but might lower the weight of the crop. Frant

16

242 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

and Kruger are of a contrary opinion. They have shown that sound
potatoes sprayed several times in the year, have a more vigorous
growth and a greater vitahty than untreated plants. The copper
treatment increases the crop of tubers (Gutzeit), even in dry seasons,
when the disease is not to be feared, in the ratio of 100 to 163, and
according to Leydhecken by 2 per cent. These observers reckon that
the bouillie bordelaise treatment is imperative in all cases, because
it is always followed by an increased crop, whether the copper acts
as a stimulant of the plant or whether it prevents the invasion of
parasites, so numerous as to lower the assimilative capacity of the
leaves by the greater or less damage which they produce in them.
The disinfection of seed potatoes, and the treatment of the stems
"With bouillie bordelaise, ahvays protect the cultivator from those
sudden outbursts of potato disease, and enables him to produce uni-
formly good crops. The phytophthora does not attack potatoes alone,
but other plants of the Solanea family, such as the tomato
(IAco]}ersicum). What has been said as regards the potato applies
to this plant. Pellegrini successfully treated this disease with a
bouillie of 3 per cent blue vitriol and 1 per cent of lime. By three
sprayings on tomatoes already attacked, the first on 15 June, the
second on 2 July, and the third on 15 July, Howell succeeded in
getting 4 per cent ol diseased fruit on the treated plot, against 60 per
cent on the untreated plot.

Phytnplitkora Phaseoli, Thaxter (Lima bean mildew). — This phyto-
phthora devastates the haricot [Phaseolus lunatiis) fields of America.
.Sturgis treated this fungi successfully with bouillie bordelaise.

Peronospora viticola, De By. (mildew of the vine). — If the water
favourable to the development of the spore contains the most minimum
amount of copper the conidia does not hatch, or if it hatches, the
germiaation tube cannot penetrate into the leaf. The object of the
bouillie bordelaise treatment is thus to prevent the conidia from forming
new hotbeds of infection by stopping its evolution. It wall be seen that
the amount of copper to be deposited on the leaves need not be great
to produce this effect, and that a w^eak bouillie bordelaise may have
the same action as the concentrated bouillie formerly used. But it is
not possible to go below certain limits. Trials made with 0'5 per cent,
and even 0*1 per cent, have shown that, if the action of the copper is
still perceptible, with 0"1 of blue, vitriol in the bouillie bordelaise, that
strength can no longer entirely prevent the hatching of the disease.
After the use of a 0'5 per cent bouillie there may still remain some
rare leaves attacked by mildew. The 1 per cent bouillies, on the
•contrary, are always suOicient, and absolutely as efficient as the
classical 2 per cent bouillie. In most cases this 1 per cent bouillie is
used. The 0*5 per cent l)ouillie is used when the treatments exceed
five in a year. By seven treatments with a 0"5 per cent bouillie,
Galloway got 99 per cent of sound grapes. It is, in fact, better to
renew a thin copper deposit on the leaves and grapes often than to
spread a thick layer two or three times a year ; the organs are con-
tinually growing, and washed by the i-ains. The great point is to
-cover all ihe surface of the vino uniformly with bouillie bordelaise by

BOUILLIE BORDELAISE. 243

copious and careful spraying. The lirst treatment can only preserve
the leaves touched ; the vine continues to grow, fresh applications are
required to preserve the organs developed between the intervals of
spraying. The treatment is oftener, and at shorter intervals, the more
intense the growth. In the South of France, the heat of summer
oitea stops all growth of the vine at the same time as the extension
of the disease. This stoppage coincides with the second, or frequently
with the third, treatment. In Central France, on the other hand,
where the heat is less intense, and the summers more rainy, the vine
grows without inteiruption the whole summer. There the number of
treatments ought to be much greater to pi'eserve all the new leaves as
developed. It is necessary to protect the grapes in the same way to
prevent "rots ". These also must be covered early with a coating of
cupric hydrate. If in hot countries three sprayings be sufficient, in the
centre and in moist years a fourth and filth ti eatment is required. A
sixth and seventh treatment is useful, especially when frequent rains
remove part of the copper deposit. In a dry year the moisture of
autumn renders a treatment necessary before the vintage. It is
especially recommende i for young plants particularly sensitive to
mildew ; this treatment enables them to retain their leaves longer and
completely ripen their wood. In districts exposed to sea-winds, which
are very favourab'e to this disease, as many as nine treatments are
given. No general rule can be laid down as to the number of spray-
ings ; it varies with the year and the district. The first treatment
must be applied before the appearance of the disease, for, owing to its
rapidity of spreading, it is sometimes too late when seen on the leaves.
To be efficient it should be applied in the second fortnight of May.
The second is applied towards the end of June, shortly after flowering,
but it should never be done during flowering. Mildew beiny- most
formidable in June, it is thus the second spraying which should be
applied with the greatest care, and most abundantly. These ireat-
ments must, according to the weather, be followed by one or si-veral
others, the last of which should be applied a fortni'^ht before the
vintage. The fear, formerly expressed, that this last vitrioliziny might
change the properties from a hygienic point of view, has been found
unjustified. Millaidet and Guyon, then numerous chemists and
hygienists, have shown that copper sa ts sprayed on grapes are conveyed
in very small amount into the vat, and are almost tota'ly eliminated
in the lees after the fermentation of the wort. Whatever may l)e the
strength of the bouillie bordelaise, the wine only contams traces of
copper, which can have no injurious effect on the health of the con-
sumer. Since 1891 the treitment of mildew by bouillie bordelaise
is compulsory in the cmton of Vaud in Switzerland. There is a
similar order in the Grisons. The prefect of Savoy has, likewise,
ordered three obligatory sprayings, the first on 20 June, the second on
20 July, and the third on 20 August. The good effect of spraying
is lauded in Italy by Hugues, Cuboni, Briosi, and Pichi, in Switzei land
by Dufour, in Austria by Schachincher, in Russia by Chmjelewski, and
in America by Galloway.

rcronoapura Schacklii (mildew of the beet). — Mr. Fuckel Just

'244 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

treated this disease by sprayings of 0-5 and 0-75 per cent of bouillie
bordelaise with a slight excess of lime. Girard found, by treating
beet-fields by a bouillie bordelaise with 3 per cent blue vitriol and
5 per cent lime, if not a total increase in the weight of the crop, at
least -^ per cent more sugar. On 35 acres, of which 4 per cent of the
beets were diseased, 5 hectolitres (110 gallons) of 3 per cent bouillie
gave the above good results.

Peronospora gangliformis, De By. (lettuce disease). — Sulphur,
formerly used by kitchen gardeners, having no action on this blight,
the mycelium of which lives in the interior of the leaves, it has been
tried to treat it with copper preparations. Young lettuce leaves are
very delicate. They require as much care as ' vine leaves, and the
bouillie must be prepared with great care. To be effective the treat-
ment must be preventive. When the bed is prepared, either for sow-
ing or transplanting, it is watered with a 4 per cent solution of
blue vitriol, or with a 4 per cent bouillie so as to reach all the
surface parts. The bed in contact with the plants is thus
disinfected. During growth a very neutral bouillie, made with
0*5 to 1 per cent of blue vitriol, is spread on the plants in the evening ,
or in cloudy weather. The effects are not so categoric as those ob-
tained in the treatment of mildew of the vine. The exceptionally
favourable conditions to the development of the Peronospora gangli-
formis created by kitchen gardening, its rapid growth demanding
several treatments close to one another, the fact that the conidia do
not give rise to the formation of zoospores, generally ten times more
sensitive to copper salts than the conidia themselves, are the causes of
some failures.

Peronosjjora Viscine, De By. (mildew of the pea and the bean). —
Treated by spraying as soon as the spots appear on the leaf.

Peronospora arborescens, De By. (mildew of the poppy). — Treated
by bouillie bordelaise before the appearance of the disease (Nijpels).
Peronosj)ora Schleideni, Ung. (mildew of the onion). — Spraying
with bouillie is effective (Nijpels).

To sum up, bouillie bordelaise forms an excellent means for treating
and preventing mildews. These diseases all have the same method
of dissemination by summer spores which enables them to become
deadly to crops in a comparatively short time, especially in a moist,
warm season. They should be treated preventively by bouillie borde-
laise at the moment the first symptoms of the disease appear, or better
still, before their appearance at the epochs propitious for the rapid
spread of this fungus. Applied with care bouillie bordelaise always
gives a perceptible and useful result, paying liberally for the cost of
the treatment. A single spraying cannot pi-oduce immunity for the
whole year, and if it l)e desired to preserve the plants from all attacks
this treatment should be applied judiciously each time that the weather
is favourable to a deadly extension of this fungus.

Plasmopara cubensis, B. et C. (mildew of the cucurbitaceffi). — This
fungus attacks Cuamius sativus, Melo cucurbita maxima, GitriUlus
vulgaris. — It may be treated by bouillies bordelaises repeated several
times a year. Selby, Halsted, Sirrine, and Stewart obtained good

BOUILLIE BORDELAISE. " 245

results. The latter produced by this treatment 102,000 vegetable
marrows instead of 20,000 on an untreated plot of the same
size.

UstilaginecB. — After the fortunate results obtained by vitriolizing
corn-seed by Kuhn's method, consisting in steepiug in a solution of
blue vitriol followed by washing in milk of lime, it was interesting to
treat corn-seed with bouillie bordelaise. Experiments in this direction
show that the action of cupric hydrate is, so to speak, nil. That is
not at all surprising seeing that the spores of the UstilaginecB are much
more resistant to copper compounds than the spores of the Perono-
sporecB. In treating the different mildews the object of spraying with
bouillie bordelaise is to prevent the spores from germinating and
penetrating into the vulnerable organs. The bouillie bordelaise can-
not destroy the very resistant zoospores or dormant spores but only
the extremely sensitive zoospores. Besides it cannot kill the winter
spores of the Ustilaginece which infect grain, and only in an indifferent
manner hinders their germination ; it cannot, therefore, prevent them
from penetrating into the young plant which it does not protect.
Hence Kellermann and Swingle declare after many trials that bouillie
bordelaise cannot replace blue vitriol in the disinfection of corn- seed.
Bedfort obtained the same negative result. After steepin'> oats-seed
in bouillie bordelaise made with 2 per cent blue vitriol and 2 per cent
lime there were as many "rust " ears as sound ears, whilst seed from
the same source disinfected the same day by 2 per cent formaline pro-
duced no diseased ears. In the preventive treatment of Ustilago
mayclis, Corda (rust of maize), Halsted found a diminution in the
disease but not its total suppression. Bouillie bordelaise cannot, there-
fore, as recommended by Van Tabeuf, replace blue vitriol in the disin-
fection of corn-seed.

Uredinece (rusts). — Bouillie bordelaise has been used with greater
or less success to treat some species of rust. The object of spray-
ing with the bouillie bordelaise was to prevent the summer spores of
the aecidium and uredo from germinating and spreading the disease.
Bouillie bordelaise cannot be used practically to combat the more
deadly rusts.

Busts of Cereals. — Numerous trials by Galloway, Swingle, and
Bartholomew, both with bouillie bordelaise and cupric borate, cupric
ferrocyanide or eau celeste, trials which consisted in practically spray-
ing every ten days the whole plant, gave no satisfactory result. This
check is attributed to —

1. The difficult adherence of the bouillie on the cereal grain.
Even if sugar, gum, or glue be mixed with bouillie bordelaise, the
plant cannot be covered with a layer of cupric hydrate capable of pre-
venting the germination of the spores to be found there.

2. The strength of the ordinary bouillies, 0-5-2 per cent, which is
quite insufficient. To obtain an appreciable result very strong bouillies
must be used, made with about 8 per cent of blue vitriol. These
might have an immunizing action on cereals, and prevent the disease,
if the great expense and the practical difficulty did not remove this
treatment from cultural methods. Galloway, Kellermann, and Cobb

246 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

thus obtained by spraying every ten to twenty days, from 28 October
to 24 June, on winter wheat fields free from rust. Swingle found
that the proportion of plants attacked by rust is thus lowered from
84'2 to 18"3 per cent. It is useless to dwell upon the failure of
bouillie bordelaise as a disinfectant of corn-seed against rust germs ;
not only does it have no effect, but it is quite useless in treating a
fungus, the method of evolution of which is so different from that of
the black rust, and which has methods of propagation which can only
diminish the effect of disinfection.

Puccinia Pruni, Pers. (rust of stone-fruit trees). — Pierce success-
fully treated this fungus by three sprayings with bouillie bordelaise
at a month's interval. The spraying was begun before flowering.
Trees so treated preserve their green lea\es.

Puccinia covvpo sit arum, Schlechtend (mildew of the compositie).- —
It is successfully treated with bouillie bordelaise

Puccinia Tanaceti, D C. — Successfully treated by Halsted.

Puccinia Bibis, Aecidium Grossularice (mildew of the gooseberry). —
Sorauer recommends preventive treatment by bouillie bordelaise.
Eriksson recommends removing the diseased leaves in the autumn,
and to spray soil and plant copiously in the spring.

Uromyces Betae, Kuhn (beet mildew). — -Nijpels relates that three
sprayings with bouillie bordelaise at a month's interval, commencing in
June, appreciably diminished this disease.

Gynosporangium SabincB, Wint. (mildew of the juniper), and
Boestelia cancellata, Eebent (pear leaf cluster cups). — Knowing the
polymorphism of this uredinse it has been recommended to overcome
this disease by destroying all the juniper-trees on which the fungus
exists in its telento and uredo forms, so as to prevent the evolution of
the fungus. It is sometimes made to disappear in that way, but very
often the disease appears on the pear-tree, when there are no junijDers
in the district. It is then necessary to resort to spraying with bouillie
bordelaise. The experiments of Weiss and Delacroix have shown that
this pi'ocess is evidently, if not absolutely, efficient. The first spraying
ought to be made before the unfolding of the leaf, the second before
flowering, and the third at a month's interval.

Pcriderniium Pini, Wall, (vesicular rust of pine bark). — In
addition to the destruction of swallowort and groundsel, preventive
sprayings with bouillie bordelaise in May have given such good results
that this method has been adopted by the Belgian Forestry Depart-
ment to prevent this disease in pine plantations.

ExoascuH di'forinans, Fuckel. — It has been suppressed by the use
of bouillie bordelaise. Benton, Taft, Selby, Duggar, Derschau, Murill,
and others, have examined the action of copper compounds on the
leaf cuil and described the good effects got by rational ap})lication of
bouillie boi'delaise. It follows from their experiments that the bouillie
bordelaise is the more active the sooner it is applied. The first spray-
ing should be done before flowering in March and April, when the buds
begin to swell. At that time strong bouillie made with 3 per cent of
blue vitriol may be used ; however, 1 per cent bouillie would suffice
(Murill). The second spraying is done after the fall of the Howers, with

BOUILLIE BOEDELAISE. 247

a bouillie made with 0-5 per cent of blue vitriol. The third spraying, if
necessar}', should take place when the leaves have reached their
normal size. The result of these operations is not always complete
the first year, but the second or the third year the " cloque " will dis-
ajDpear if care has been taken of the trees in this way. The " cloque ""
will not again appear if one or two preventive spraj'ings are given
every year. The beneficial action of bouillie bordelaise is surprising.
It is generally allowed that cupric sprayings can exert no destructive
action on fungi, the mycelium of which grows in the interior of the
tissues. The preventive use of bouillies in different diseases should
have no other object than to preserve the tissues, by preventing the
spores which are deposited thereon from producing the disease. It is
otherwise in regard to the leaf curl, where the bouillie is used as a
curative agent. We know so little as to the method of propagation of
the "cloque" (the artificial infection of peach-trees by spoi'es has
never succeeded) that we cannot exactly define what is the role played
in its suppression by spraying with bouillie bordelaise. We believe,
however, that, in this case the copper compounds deposited on the
peach-trees destroy the mycelium of the leaf curl. The peach be-
haves in a special way towards cupric compounds. It can dissolve
insoluble cupric deposits on its organs in quantities poisonous to the
fungi and itself. It follows that the effect of the bouillie bordelaise on
the health of the plant is identical with that produced by spraying
with pure blue vitriol. In most cases the use of cupric bouillie,
even that of weak bouillie bordelaise, produces the partial or total fall
of the leaf reached by the preparation. These which do not fall are
riddled with holes, or seriously attacked. Are we to admit that the
m^'celium, which almost crawls on the leaf, since it is lodged between
the epidermis and the cuticle, and is very little protected by the tissues,
undergoes the first poisonous action of the salts of copper absorbed by
the leaves? Or must it be admitted that the action of the bouillie
bordelaise results solely from the fact that the mycelium localized in
the leaves is necessarily suppressed at the same time as the disease by
the fall of the leaves'? In our opinion beneficial action of bouillie
bordelaise results from the two following facts : (1) destruction of the
mycelium of the Exoasnis lodged in the buds in the spring ; (2) its
suppi-ession, by the fall of the infected leaves in which the disease is
localized. The fall of the leaves, incidental to the treatment, has I'o
deadly action on the evolution of the tree, and there is nothing at
which to be alarmed. The copper absorbed by the plant stimulates
it, and causes a more rapid and more intense growth, so that the tree
in summer and in autumn would be moi'e vigorous than untreated
trees. We therefore possess in bouillie bordelaise a curative remedy
for the leaf curl of the peach, a remedy which may be of great
service to gardeners. We insist, therefore, on this point, that the
treatment to be complete should extend several years, and should
enter into the common customs of the orchard. Not only the crypto-
gamic diseases of the peach will be suppressed, but the quite excep-
tional vigour of the trees treated will enable better crops to be secured
than on untreated trees.

248 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Exoascus Priini (pockets of the plum). — Sturgis asserts that he
obtained a radical cure of the disease by bouillie bordelaise,

Eryslphe com^nunis, Wallr. (mildew of the pea). — This mildew
is successfully treated by sulphur. Nijpels asserts that one or more
sprayings with bouillie bordelaise likewise cures the disease.

Uncinula americana. How. (oidium of the vine). — The mycelium
crawls on the surface of the leaf and there produces its organs of re-
production. It was possible that this fungus, protected less than any
other by the tissues of the nurse plant, might be readily destroyed by
copper salts. It was also hoped to be able to suppress the sulphurat-
ing used against this disease by replacing it by vitriolization. This
process would have much simplified the dressings required against the
cryptogamic diseases. Neither blue vitriol nor cupric hydrate have,
however, any curative or preventive action on this fungus, and it
vegetates quite as well on leaves covered with bouillie bordelaise as
on untreated leaves. The treatment for mildew being an absolute
failure against oidium, it remains necessary to continue the sulphurating
of the vines at the same time as the vitriolizing with bouillie bordelaise.
Up to 1902 it was thought preferable to separate the two treatments.
It seemed in the beginning that there was no drawback in the
fact that one of the operations was conducted before the other, and it
was the sulphuring, as the oldest known, with which the vine-growers
began ; but in considering the mechanical phenomena which are pro-
duced in this case on the surface of the leaf, it will be understood
why it is necessary to precede the first sulphuring by vitriolizing. If
the first treatment be sulphuring, the sulphur deposited on the leaves
mechanically fixes a large part of the bouillie, which will not adhere
to the leaves, and forms large uncovered spaces. There is really
neither complete sulphuring nor vitriolizing. If, on the other hand,
we vitriolize first and sulphur as soon as the spray is dry, the adher-
ence of the sulphur is increased, and the two remedies have their full
action on the cryptogamic diseases which they should overcome. To
simplify the work of the vine-grower it has been tried to unite these
two treatments in a single one ; say by mixing the sulphur with finely
pulverized copper salt, or by mixing the sulphur in the cupric bouillie.
In the beginning the use of these mixtures often gave negative or very
incomplete results, so that Polacci, P. Viala, Mach, and Mar^s have
condemned them as unfit to cure or preserve the vine from
oidium or mildew, because the copper salts by seizing the vapours of
sulphur poisonous to the oidium converted them into copper sulphide,
inert towards mildew. In 1902 Guillon reported to the Academy of
Sciences the altogether satisfactory results oi)tained with sulphurated
bouillie bordelaise in the Charente. Without denying the reactions
which may occur between copper derivatives and sulphur, Guillon has,
however, observed that these are slow to occur, and that bouillies
sulphurated immediately after their preparation may act simultaneously
oa the two diseases before the sulphur has acted on the cupric hydrate.
To mix the sulphur in the bouillie it is necessary to moisten it suitably.
For this purpose watoi- o)- the bouillie must be allowed to fall, drop
Jjy drop, on the sulphur whilst stirring. It is, however, preferable to

Lb.

Lb.

70

85

•20

10

10

5

BOriLLIE BORDELAISE. 249

incorporate it in the milk of lime. By adding the sulphur gradually to
the milk of lime a yellow, homogeneous paste is obtained, which is after-
ward run into the solution of blue vitriol. This operation of moistening
sulphur is, moreover, now simplified by the use of the moistenable-
sulphurs of commerce, the composition of which is as follows : —

TABLE XLV. — Showing Compositio7i of Moistenable Sulphur.

Sublimed sulphur ....
Carbonate of soda ....
Powdered rosin

By adding, at the time of application in the vineyards, 2 lb. of the
moistenable sulphurs to 1 lb. of blue vitriol in solution, there is ob-
tained forthwith a sulphurated bouillie bourguignonne. This bouillie,
used as soon as made, possesses the double property of preventing
oidium and mildew. The more freshly made the more it adheres.
The amount of sulphur used in these sulphurated bouillies, as Guillon,
Cucovitch, and Gervais have shown, should not be more than 2 or
3 per cent. But these bouillies have one defect, the sulphur tends to
deposit ; on the other hand, they have the advantage of containing
perfectly neutral sulphur, which can no longer burn the leaves. The
sulphuric asid cont lined in the sulphur, and which is often the cause
of these burnings, is, in fact, often neutralized in these bouillies by
the lime or by the carbonate of soda. So the direct producers most
sensitive to sulphur, which generally cannot be sufficiently protected
against oidium, behave well towards sulphurated bouillies. The latter,
by the readiness by which they lend themselves to the simultaneous
treatment of different cryptogamic diseases, constitute a real progi-ess.
Their use eaters more and more into current practice, the more so as
the results obtained by Guillon are confirmed. Cucovitch pointed
out, in fact, at the International Agricultural Congress held at Eome, in
1903, the very decisive results obtained against mildew and oidium
with a bouillie of 1 per cent of blue vitriol, 1 per cent of lime, and
2 per cent of sulphur. Prosper Gervais likewise submitted his vine-
yard of Gausses to this new treatment, and found four treatments of
sulphurated bouillie act as well as four sulphurings and vitriolizings
as ordinarily performed. The first treatment took place before flower-
ing, when the twigs of the stem had reached 12 inches. The
second was made after flowering, as soon as the fruit became apparent.
The third in the fii'st forinight of July, and the fourth in the first
fortnight of August. A single sulphuring, abundant and penetrating,
was made at the time of flowering, by means of Vermorel's torpedo,
against the dropping of fruit and accidents of fertilization. According
to the experiments of Hoc, Quantin, Trabut, and Seignouret, it would
appear that the mono- and polysulphides of copper also act on oidium
and mildew, from which it would appear that the sulphurated bouillie
must act in any case. It is, however, acknowledged that sulphurated
bouillies containing no sulphur compounds of copper render the
most regular service in the struggle against these two diseases. In
.spite of its notorious failure against oidium of the vine, bouillie horde-

250 INSECTICIDES, FUNCtICIDES, AND WEED KILLERS.

laise is recommended to overcome the fungi of the same family as
oidium. Thus Selby recommends bouillie bordelaise to overcome: —

PodosphcBra OxyacanthcB, D. C, blight which invades the apple
and the cherry tree in America, but which in Europe only produces
the hawthorn blight.

Sphcerotheca Morsuvce. Berk et Courte (blight of the gooseberry),,
which invades the fruits of this shrub in North America to such an
extent as to entirely destroy the crop.

Sphcerotheca pannosa, Lev. (mildew of the rose-bush and peach-
tree). — The reports of cures obtained by treatment with bouillie
bordelaise are numerous. Eitzema Bos, Nijpels, and Speschneff
recommend this treatment to overcome this disease. Nijpels recom-
mends bouillie bordelaise to overcome : —

Microsphcera Grossnlarice, Wallr. (mildew of the gooseberry). —
However, bouillie bordelaise will not act so efficiently and decisively
as sulphur at a high temperature, and cannot be advantageously used
to overcome blights.

Hypomyces perniciosus, Magnus (mole disease).- — This disease
causes considerable damage in mushroom beds. Constantin and
Dufour submitted the spores of this injurious fungus to the action of
bouillie bordelaise and found that prolonged steeping in a 2 per cent
bouillie does them little harm, and it is only after three to seven days''
steeping that the spores are killed.

Nectr ia ditisswia, Tul. (canker of the pear, apple, and beech trees) ;
Spceropsis malorum, Peck, (apple rot, pear rot, quince rot). — To-
prevent these diseases Selby and Paddock recommend to scrape the
trunk of the trees, to clean the wounds, and to spray the whole tree
with bouillie bordelaise. This process has no action on already formed
cankers. Only their deep excision, followed by coating the living
wounds with a concentrated solution of green vitriol, acidulated by
sulphuric acid, can suppress them and cure the tree.

Polystigma rubrum, D. C. (plum leaf blister). — Sorauer and
Nijpels recommend to prevent this disease to carefully burn the
dried leaves and to spray preventively with bouillie bordelaise on the
young spring leaves, or on the branches before the opening of the buds.

Cricu/nardia Bidirelli, Viala et Eavaz (black rot of grapes). — In
1887 trials were made at Ganges with blue vitriol. In spite of the
negative results of these trials the experiments were resumed the
following year at Aiguillon with bouillie bordelaise on a certain
number of black-rotted vines in 1887. After three sprayings, made
before the end of July, the stocks treated only had 14-2-i per cent of
diseased grapes, whilst the untreated vines which surrounded them
had 95-99 per cent. Great pul)licity was given to these fortunate
results, so as to enable vine-gi'owers to take in time the necessary
steps to prevent the extension of black rot around the hotbeds of in-
fection. Experience shows that liouillie bordelaise does not act on
black rot as on mildew. The summer spores of black rot being much
less sensitive to the action of cupric preparations than the zoospores
of mildew, it is necessary to use stronger bouillies and spray more
often. This fungus may develop, like mildew, with unheard-of rapidity.

BOUILLIE BORDELAISE.

251

and cause irreparable damage in fort5'-eight hours. The time of
treatment should thus be chosen with circumspection, and the number
of sprayings subordinated to weather favourable to the evolution of the
parasite in question. Whilst dry, cold weather may completely stop
black rot, on the other hand, moist, warm weather gives it full scope.
It is therefore at such a time that it is most advisable to spray, and con-
tinue to do so at very short intervals. If in most cases three sprayings
suffice, seven to ten are required in moist seasons (Prillieux and Viala).
Dussuc advises the use of the following sprays : —

TABLE XIj\I.—Sh-ming the Composition, Volume Per Acre, Time of Treat-
ment, and Order of Sequence of Boiiillies Bordelaises used in the Pre-
vention of Black Rot of Grapes.

Order of
Treatments.

Gallons of
Sidiition
Per Acre.

Strength Per Cent
of the Solution.

1

Time of ]
Treatment.

Blue Vitriol.

Lime.

First
Second

Third
Fourth

17-t)
26-4
35-2
44-0

1

3
4
5
6

8
3
8
3

May '
June
July
August

Dussuc believes the above gradually increasing quantities, used
at the different times of sprayings are indispensable, so as to cover
the entire surface of all the green parts of the vine. One of the
essential conditions of success rests, in fact, on the care taken to spare
neither the upper nor under surface of the leaves. When the vines have
tufts which prevent the uniform penetration of the liquid, they should
be further treated with jDOwders containing blue vitriol and sulphur.
By alternating the spraying with bouilhe bordelaise and with pow^ders,
the results obtained leave nothing to be desired. Lamson, Scribner,
and Pearson recommend, in America, four to five sprayings, the first
of which is made on 5 May, and the last in autumn. Trials on the
large scale made in America by 250 vine-growers secured to them a
profit of £7400 (Gallowav). The 4-6 per cent bouiUies, used in the
beginning, are now abandoned and replaced by 2-3 per cent bouillies.
In France four treatments are the rule, and should be applied at the
following periods in most instances (Couderc) : —

TABLE XLXU.—Shotving Order, Time of Spraying, and Strength of Bouillies
in Treatment of Black Rot of Grapes (Couderc).

Order of
Treatments.

Tim' of
Sprayiiig.

Streiiqth of Bouillies,
'Per 'Cent.

First
Second
Third

Fourth

First week of May
Second week of May
Last fortnight of June

Last fortnight of July

2 Blue vitriol, 2 lime
2 Blue vitriol, 2 lime
8 Blue vitriol, 2 lime

( 3 Blue vitriol, 2 lime,

1 2 molasses
1

252 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

These epochs have been fixed according to the periodical develop-
ment of black rot. Prunet, who examined black rot very closely,
points out the parallelism between the evolution of the parasite and
that of the vine, and has based on this fact a rational course of treat-
ment, here given in full. The first invasion especially attacks the
leaves, which on the vine branches, the first shot forth, are included
between the third and the eighth ; the second attacks chiefly those in-
cluded between the tenth and the eighteenth, and in addition the
pedicles of the flower and grape stalks ; the third attacks the fruit
when they are the size of a big pea, and also the leaves above the
eighteenth ; finally, the last attacks the fruit when of almost normal
size. With such data, we ought to operate according to the intensity
of the disease.

I. In the most intense hotbeds of disease.

II. In spots attacked rather strongly.

III. In those attacked feebly, or to an average extent.

I. 1st sulphating when 5-7 leaves on first branches.

2nd „ „ 7-9

3rd „ ,, 10-13

4th „ „ 15-18

5th „ ,, the grapes show themselves.

6th ,, „ ,, are big as a large pea.

7th ,, ,, ,, are almost full size.

II. Ist sulphating when 5-8 leaves on first branches.

2nd „ „ 10-13

3rd „ „ 15-18

4th ,, as soon as grapes appear.

5th ,, when grapes are size of pea.

III. Does not differ from preceding except by suppressing second
treatment.

Where vineyards have been treated as soon as the disease appears
•success is complete and the disease easily overcome. However, if the
formidable fungus has been allowed to develop without any obstacle
before treatment, the perithecae which spread the disease are so
numerous that very often ten treatments do not give a complete result.
This is especially the case when by negligence the black-rotted grapes
have been left on the stock. It is thus advisable to support the spring
and summer treatments by energetic winter treatments and by pre-
cautions which complete these treatments. In spring and in summer
the spotted leaves must be removed ; if one is surprised by the disease
remove the buds and young branches from the stock so that the stem
may be better aerated, and that the axillary sprouts do not form a
dangerous neighbourhood for the grapes. In winter the leaves and
attacked grapes left on the stock must be burned, then the stocks must
be treated as for anthracnose by concentrated and acidulated solutions
of green vitriol, so as to destroy, if possible, all the perithecae which
the following year transmit the disease to the vine. The strong doses
of blue vitriol which enter into the composition of the bouillie used to
combat black rot render the struggle against this disease very onerous,
iind almost impossiljle in districts where low quality wine is produced
at a low price. Numerous trials have, therefore, been made with
weak bouillie. In America especially it has been tried to overcome

BOUILLIE BORDELAISE.

253

black rot with the bouilHes in use against mildew, and encouraging
results have been obtained. Galloway submitted different vines to
the different treatment summed up in the following table : —

TABLE XLVIII. — Showing Results of Repeatedly Spraying Vines with Blue
Vitriol Sohitions of Various Strengths.

Composition

of Botiillie,

Per Cent.

Number of
Sprayings.

Date of Spraying.

Sound

Grapes,

Per Cent.

8-25 blue vitriol

1-6

3-25

1-6

3-25
1-6

Untreated

6
6
4

4

3
3

27 April, 13 May, 25 May,

9 June, 22 June, 7 July
27 April, 13 May, 25 May,

9 June, 22 June, 7 July
27 April, 13 May, 25 May,

9 June
27 April, 13 May, 25 May,

9 June
9 June, 22 June, 7 July
9 June, 23 June, 7 July

94

93

89

90

22-5

13-5

1-1

These experiments show plainly that the concentration of the
bouillies is less important than the frequency of sprayings, and the
choice of the time at which they are executed. Trials with 0*5 per
cent bouillies gave favourable results, and Ecluse recommends to
overcome black rot by the classical treatment for mildew, provided
the first May spraying be done with a bouillie of 6 per cent of blue
vitriol and 3 per cent of lime. It is not impossible for weak bouillie
to give good results, but it must not be forgotten that in many cases
the struggle is difficult, and the treatment applied against mildew is-
impotent against black rot. We therefore believe that it is indispens-
able to follow the method so carefully studied by Prunet, consisting in
the use of 2 per cent bouillies, a method capable of entirely preventing
black rot, and of which the efficiency against mildew is absolute.

Coniothyrmm Diplodiella, Sacc. (white rot, pale rot, livid rot). —
Although the preventive or curative treatment against this disease
gives imperfect results, none the less it is recommended by Viala and
Sorauer. But its application is difficult, because to obtain a satis-
factory result the preventive sprayings on the grape must be done
immediately after the formation of the wounds on the grape stalks, so
as to prevent the spores from penetrating into the wounds.

Alternaria Solam, Sor. ; Macrosporium Solani, Ell. et Mart. — Eolfs,
Weed, Selby, Burrill, McClure, Earle, and Galloway declare that
bouillie bordelaise overcomes this disease. Galloway advises a bouillie
of 1*5 per cent blue vitriol and 1 per cent of lime. The first spraying
is done with care, before the spots appear on the plant, so that all the
leafy surface is covered with cupric hydrate.

Alternaria Brassicae f. nigrescens, Peglion (scorching of the leaves,
of the melon). — The use of bouillie bordelaise was advised by Peglion.
It gives good results. The first spraying should be given the moment.

•254 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

the small spot appears on the leaves and young shoots, and the second
fitteen to twenty days later. A better result is obtained by adding a
little sugar or ammonium chloride to the bouillie. Smith recommends
in this case 1 lb. of sugar or -|^ lb. of ammonium chloride to 15 gallons
of water.

SjjkareUa Fragaria, Sacc. (spots of the leaf of the strawberry). —
Garman advises to overcome this disease a bouillie bordelaise with
3"25 per cent of blue vitriol and 2 per cent of lime, used to spray
every fifteen days until it disappears. Weiss has shown that a 1 per
cent bouillie sufiQces when used as spray before flowering, and after
gathering the fruit. This bouillie is very adherent on the strawberries
so that it cannot be used during the formation of the fruit, which
could not be sold.

CylindrosjMrium Padi, Karst. (cherry and plum leaf blight). —
This disease which, in America, causes the leaves of plum-trees and
pear-trees to fall, is effectively overcome by three sprayings with
bouillie bordelaise in July and August (Selby). According to Galloway
and Pammel the bouillie bordelaise is a specific remedy against this
disease. The best is a bouillie of 1"25 per cent of blue vitriol and
0"8 per cent of lime. According to Fairchild and Sorauer the trees
should be sprayed five times — the first before the opening of the leaves,
tlie following with fifteen days' interval. It is essential that the
bouillie cover the two faces of the leaves.

Spharella mori/oUa, Passerini {Cylindrospo'rium Mori Bert), (mil-
dew of the leaves of the mulberry). — Bouillie bordelaise 5 per cent gives
excellent results (Caruso).

Septoria. — Trials against these diseases show that Louillie bordelaise,
judiciously applied, is an excellent method for overcoming them,
especially if the first spraying be applied preventively belore the
opening of the young leaves.

Septoria Tritici, Desm., and Septoria graminum, Desm. (nielle
des cereales). — Kruger steeped the spores of the pycnides for twenty to
forty hours in a 2 per cent bouillie bordelaise a ad found that they did
not germinate after this treatment. Galloway observed a diminution
in this disease in treating grain against rust by cupric preparations.

Septoria Ribis induces the premature fall of gooseberry leaves.

Septoria Itubi, Wert., produces p ile spots bordered with red on
raspberry and blackberry leaves. Selby, Goft', and Pammel overcame
this fungi by spraying with bouillie bordelaise. May be overcome in
the same way : —

Septoria Lycopersici, Speg. (spots of the tomato leaf). — Selby;
Halsted, and Earle.

Septoria Peiroselini, Desm. (pale spots of the parsley). — Duggar and
Bailey.

Septoria Cerasina, Peck, (spots of the leaf of the plum-tree, cherry-
tree, apricot, and peach-tree in .America). — With three sprayings there
is a marked but incomplete effect. Spots of the leaf of the chrysan-
themum in Italy by five to six sprayings, containing a little soap.

Se/Uoria nigerrima, Puckel, and Sej)toria piricola, Desm. (white
spots bordered with brown on the pear-tree). — According to Sorauer

BOUILLIE BORDELAISE. 255

this disease is overcome by several sprayings, tlie first of which is
given hefore the opening of the buds. According to Weiss bj^ a spray-
ing before and after flowering. This treatment is better than by
potassium sulphide (Duggar).

Gloeosporimii Bibis, Mont, and Desm. (curiant leaf spot). — Weiss
advises to overcome this disease preventively by two sprayings, the
first before the opening of the buds, the second after flowering.

Gloeospori 1(1)1 carvatuin, Oudem. (disease of the leaves of the goose-
berry).— Sorauer recommends the preceding preventive treatment
by bouillie bordelaise.

Gloeosporltim Juglandis, Mont, (walnut leaf disease). — Injurious
to young plantations, it is combated preventively by spraying with
bouillie bordelaise (Sorauer).

Gloeosporium venetam, Speg. (raspberry spot, in America). — Selby
and Green recommend preventive treatment with bouillie bordelaise.

Gloeosptorium frutigenuvi, Berk, (bitter rot of the apple). — Garman
and Stinson overcome this disease by four sprayings, the first before
the fall of the petals, and the three others at fifteen days' interval.

Gloeosporiuni phomoides, Sacc. (anthracnosis of tomato, in America).
— Halsted advises spraying with bouillie bordelaise.

Gloeosporium macropus, Sacc. (orchid disease, especially the
varieties Laelia and Cattleya). — Mangin advises a 2 per cent bouillie
bordelaise.

Amongst the great number of Phyllosticta, Pers., which are char-
acterized by the small round spots which they form on their nurse
plants, only the following have been tried with bouillie bordelaise : —

Phyllosticta sphmropsidea, Ell. et Ev. (horse chestnut [j^sculus
Hippocastanuvij leaf disease). — Fairchild has used bouillie bordelaise
as a preventive with success.

Phyllosticta Pirina, Sacc. (pear-tree leaf spots). — Weiss has over-
come tliis disease with bouillie bordelaise.

Fasicladium Pirinum, Fuckel (pear scab) ; Fusicladium dentriti-
cuni, Fuckel (apple scab). — It is very important for orchards to pre-
vent this disease. The knowledge of the evolution of these fungi
enables it to be overcome preventively. It is above all necessai-y to
prevent tne transmission of the disease from one year to another by
destroying the holed branches, the spotted leaves and fruit, on which
are formed the winter spores which infest the young organs of the
new vegetation in the spring. This wise precaution is far from
sufficient. The whole tree must be disinfected chemically by cover-
ing all its pans with a concentrated solution of green vitriol, acidu-
lated by sulphuric acid, say with a concentrated bouillie bordelaise
containing 4-5 per cent of blue vitriol and as much lime. Ricaud
was the first, in 1866, to treat fruit trees with bouillie bordelaise.
He advised to treat the walls and the trellises against which the
trees are nailed up in the same way. It is almost indispensable to
spray the soil copiously around the tree in autumn and spring, so as
to disinfect the surface layer of soil, on which numerous germs of
cryptogamic disease always fall with the leaves. A soil containing 4
per cent of bouillie bordelaise in no way affects the germination of

256 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

seeds which may be afterwards sown around the trees. There are no
vexatious consequences to be feared (Frank and Weiss). Winter
treatment, however well done, does not exclude the different summer
treatments required to prevent this disease entirely. Physiologists
who have studied the question advise two spring sprayings with
bouillie bordelaise. Stinson by three sprayings, the first of which was
at the end of April, the second in the middle of May, and the third in
the beginning of June, got 95 per cent of healthy apples and 5 per
cent of spotted ones, whilst 91 per cent of the apples on the untreated
trees were attacked. Maxwell found seven sprayings were required
to cause the disease to disappear entirely.

TABLE XLIX. — Showing the Effect of the Number of Sprayings with Botiillie
Bordelaise on the Percentage of Diseased Pears.

Spotted Pears,
Per Cent.
Trees sprayed twice yielded .... 3-17

„ ,, three times yielded . . . 3-57

„ ,, seven times yielded . . . 0*00

The bouillies recommended in the beginning by Eicaud were made
from blue vitriol 2 per cent and lime 3 per cent. But apples and
pears, particularly those which were grafted on quince-trees, were
too sensitive for these bouillies. The strength has been greatly re-
duced and equally satisfactory results got with 1 per cent or even
0"5 per cent. Taft ascribes the corrosive action of these bouillies on
the leaves of apple and pear trees to the excess of lime which they
mostly contain ; he therefore advises absolutely neutral bouillies.
Muller found that whilst pure cupric hydrate produced symptoms of
poisoning on the plant, a 4 per cent milk of lime had no effect. He
observed that bouillies containing little blue vitriol (say 0'5 per cent)
and much lime (4 per cent) produced less burns than neutral bouillies,
even of 0'5 per cent.

The object of multiple treatments is to cover not only the leaves
and the young shoots with bouillie bordelaise, but also the young
fruits. The number of sprayings evidently depends on the weather,
as in the treatment of the vine against mildew and black rot. If
frequent rains wash the leaves and fruit, and favour by moisture the
development of summer spores, sprayings should be more frequent
than in warm, dry weather. The first treatment is before flowering,
the second immediately after flowering, and the third when the fruit
is the size of a pea. Since 1886 Goethe, Mohr, Kruger, Caruso,
Peglion, Lodeman, Munson, Taft, Sturgis, Stinson, Beach, Prillieux,
Nijpels, Hotter, Sorauer, Muller, etc., have demonstrated the absolute
efficiency of treatment with bouillie bordelaise against the scab.
Galloway, Fairchild, and Beach have moi'e especially observed the
physiological effect produced on the tree by spraying. The ravages
of the Fusicladium must not be looked at from a mere money point
of view, because they render the fruit unmarketable. Like all leaf
parasites they do damage to these organs of assimilation and injure
the health of the tree. The life of the plants is concentrated, on the
one hand, in the leaves, and on the other hand, in the roots. Between

BOITILLIE BOKDELAISE. 257

these organs there exists an admirable correlation when they are
intact, but as soon as one of these cannot fulfil its physiological
functions, the other suffei'S. If the leaves are killed by parasitic fungi
the roots cannot do their part. The sap which ascends, however rich
it- may be, cannot nourish the plant if this sap is not elaborated by the
leaves ; respiration is affected, assimilation is defective, the alimentation
of the different organs of the plant by the descending sap is inefficient ;
if the leaves fall or are entirely destroyed life ceases. It is therefore
important to prevent all wounds on the leaf, to stimulate their develop-
ment, and to keep them as long as possible in a state of health.
That is realizable if the many sprayings with bouillie bordelaise are
included in the necessary and normal dressings of fruit trees, as in
the orchards of Sweden and America. A tree regularly and systemati-
cally treated with bouillie bordelaise keeps its leaves healthy. By its
stimulating effects cupric hydrate prolongs the vitality of the leaves
until late in the season, and the growth of the trees being thus pro-
longed, become more vigorous than those which have not undergone
this treatment. The amount of copper required to produce this re-
markable physiological effect is almost infinitesimal, and the bouillies
used need not be prepared with more than O'O per cent of blue vitriol.
Fruit trees being very sensitive to pure blue vitriol, it is necessary
that the bouillie bordelaise be prepared with great care.

Fusicladmm Cerasi, Sacc. (black spots of the cherry). — Sirodot
recommends the treatment and precautions used against apple and
pear spots.

Entomosjporiuvi maculatum (leaf scald of pear and quince tree) ;
Entomosporium Mesjnli, Sacc, or Morthiera Mesjnli, Fuckel (spots of
the leaf of the pear). — The fruit trees are treated as indicated for
Fusicladium. Galloway, Pearson, Chester, Sturgis have made several
trials in this direction. They show that by several sprayings annually
the ravages of this fungus may be prevented. In the beginning a
3 per cent bouillie of blue vitriol and 2 per cent of lime was used ;
but it was found that weaker bouillies are capable of rendering the
same service. Maxwell obtained the following results wdth a 2 per
cent bouillie : —

TABLE L. — Shotving the Effect of Repeated Spraying with a 2 Per Cent
Bouillie Bordelaise on the Percentage of Diseased Pear-Tree Leaves.

Percentage of
Diseased Leaves.
Untreated trees ......... 75-84

Twice treated trees, 25 April, 9 May ..... 3*17

Three times treated trees, 14 April, 25 April, 9 May . . 3-17

Seven ,, „ „ 14 April, 25 April, 9 May, 5 June,

25 June, 14 July, 5 August . . 0-00

To prevent great damage two sprayings suffice ; but the disease is
not entirely stopped until after multiple treatments. Waite advises
a single treatment at the right time, that is to say, when the leaves
are two-thirds of their normal size. Fairchild lowered the strength
of the bouillie to 1-2 per cent of blue vitriol and as much lime, and
obtained the same favourable result by repeated sprayings as with

17

258 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

concentrated bouillie. Sorauer and Stoll also found excellent results
from bouillie bordelaise used before tbe opening of the leaves.

Golletotrichum Lindemuthianum, Br. and C. (anthracnose of the
haricot and scarlet runner). — Beach overcame this disease preventively
before S3wing by steeping the haricot beans in bouillie bordelaise, and
afterwards spraying the plant with a weak bouillie of 0'8 per cent of
blue Vitriol and 0"5 per cent of lime. The first spraying was done
before flowering, and the succeeding ones at fifteen days' interval,
avoiding, however, spraying on the flowers, as the fructification would
be hindered by the bouillie.

GoUetotrichuvi oligochcRtum, Cav. {NuUe or anthracnose of the
melon). — Sprayings with bouillie bordelaise produce no effect if used
curatively (Prillieux) ; on the other hand, by their preventive use
Selby and Halsted obtained excellent results.

Cercospora Ajni, Fr. (celery leaf spots). — This disease causes much
damage in America, and methods of defence against it have been
studied in that country. Halsted advises bouillie bordelaise, Duggar
and Badey bouillie bourguignonne.

Cercospora Beticolcz, Sacc. (beet leaf spots). — Halsted recommends
spraying with bouillie bordelaise.

Cercospora BesedcB (mignonette leaf spots). — Fairchild advises a
preventive treatment, consisting of three sprayings with a bouillie of
3 "25 per cent of blue vitriol and 2 per cent of lime.

Cladosporiurn fulvum, Cooke (tomato leaf rust). — Curative treat-
ment by cupric preparations is inefficient. On the other hand, a pre-
ventive treatment removes the disease. The evolution of the disease
is slow. Spraying must be done early on the absolutely healthy plant
'(Galloway), and fresh spraying done every week (Eolfs). Selby,
Halsted, Nijpels, and Earle point out the good effects of preventive
treatment with bouillie bordelaise.

Gladosporium Cucuvierimim, Ell. and Art. — Frank did not obtain
favourable results with cupric preparations, because the spores of this
fungus have a great resistance to copper salts. Selby, on the contrary,
w^as quite successful.

Cladosporiu7n Carpophilum, Thfim. (spots of the cherry, plum
scab). — Selby advises bouillie bordelaise to overcome it like Fiisi-
cladium.

Cycloconium Oleagirmm, Castagne (olive leaf spots). — At the Agri-
cultural Institute of Pisa 200 olive-trees were successfully treated against
this disease with a 0'5 per cent bouillie, used four times in July, then
in September, October, and November. The olive-trees so treated pre-
served their leaves intact, whilst the untreated had suffered much
from the parasite. Vennuccini advises two preventive treatments,
the first with a i per cent l)0uillie in winter, the second with a 0-5 per
cent bouillie in spring. Jirizi confirms the good results got by this
treatment.

Heterosporium cckinulatum, Cooke (fairy ring of carnations). —
Selby overcomes this disease by bouillie bordelaise.

Lophodermium Pinastri, Chev. (pine leaf cast, fall of the needles
of the pine). — In 1888 Bartet and Vuillemin found in bouillie borde-

BOUILLIE BORDELAISE. 259

laise an excellent method for preventing this disease. Their experi-
ments iu the Bellefontaine Nursery, near Nancy, gave very decisive
results. Two treatments with houillie bordelaise on two to three-
year-old plants, the first be,;:innino; in June, when the needles are half
formed, the second a month later, when they are fully developed,
assured the complete immunity of the young plants, w^hilst 80 per
cent of the untreated succumbed to the disease. Beck and Oster-
held tried this treatm-nt on a larger scale, and as far back as 1889
this process entered mto the forestry practice of Bavaria. Von
Tubeuf likewis-^ controlled the efficiency of cupric preparations on an
experimental field at Dahlem. His experiments show ihat houillie
bordelaise produces more effect in August than in June or September,
and that it was superior to other cupric preparations. Bouillie borde-
laise cannot destroy the m> celium developed in the interior of the
plant, hut it protects the sound needles of a pine-tree already inv ided
by the disease. Young plants which still have the greater portion of
the leives may b^^ pies^-rved if the heal'hy leaves are protected by
energetic spraying ac the moment when ihe new shoots have reached
two-thirds of their height. The first treatment should be given in
June, the succeeding ones very carefully in July and August, for it is
at that time that the invasion is the most intense, and that the leaves
should be entirely protected by a layer of capric hydrate.

Sderotinia Cydonice, Schell. — This disease invades quinces and
mummifies them. It may be overcome by spraying the tree before
the opening of the leaves (Sorauer).

Monilia frii'Agena, Pers. (brown rot of kernel fruits). — To prevent
this disease the mummified fruits, brown before the harvest, must be
collected in winter and carefully destroyed, for, as shown by Gilloway,
brown rot can only be overcome with difficulty by bo'-illie bordelaise
and other anticryptogamic products. Chester, by six sprayings a year
with a big bouillie, from 29 April to 2 July, found that the number of
diseased fruit was lowered from 32 per cent to 13 per cent ; but that
the disease cannot be entirely prevented. Montemartini likewise found
the bouillie inefficient. Schoyen advises against this disease spraying
before the opening of the buds.

Botrytis cincrea (vine sderotinia). — Bouillie bordelaise is gener-
ally regarded as inefficient against the mould of grapes in autumn.
Sorauer and Beauverie believe that, above all, the air should be allowed
to penetrate more easily around the fruits by partially stripping the
leaves and in cutting the shoots around the grapes, and to spray after-
wards.

Use of Bouillie Bordelaise against Insects. — Cupric hydrate,
deposited uniformly on the green parts of a plant, protects these against
the attacks of insects and their larvae. Plants regularly treated by
bouillie bordelaise are less sought after than untreated plants. After
eating leaves blued by a deposit of cupric hydrate insects and their
larvae are poisoned and die. The contact and the presence of cooper
are so disagreeable to them that they often quit the tree after treat-
ment with copper hydrate. Thus the caterpillars of the Hyponomaute
of the apple abandon the silky gauze which serves to them as a shelter,

260 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

and let themselves fall on the ground after spraying with bouillie
bordelaise (Sonnino). The Eriocampa adumbrata (slug- worm or slimy-
caterpillar), the catei'pillar of the Liparis dirysorrhea, L., that of the
Gastrojyacha neustria (the lackey or barred tree lackey moth), are
killed, according to Goethe, by the absorption of the blued leaves. The
Leptinotarsa decemlineata (Colorado beetle) may be overcome by bouillie
bordelaise. The trees sought after by the anthonome of the apple-
tree may be protected by spraying with bouillie bordelaise (Montillot).
The vines treated regularly by bouillie bordelaise are abandoned by
the Altise and the Pyralis (d'Andoque de Seriege, Martini). In general
injurious insects are seen to diminish greatly in gardens where the
trees are treated with cupric bouillie. Debray advises spraying with
2 per cent bouillie bordelaise to destroy Cassida viridis, L. (coleoptera
injurious to artichokes) and the caterpillars of the Pier ides, injurious to
the crucifers, rapes, cabbages, turnips, etc. This preparation has also
been used successfully against the gooseberry saw-fly, Tenthredo Gros-
sidarice. It also diminishes the number of the Eriophyes Piri, Pgst.,
which cause the "cloque" of the pear-tree, and destroys the insect in-
jurious to melons and vegetable marrows, Diabrotica vittata, Fab.
(Sirrine). Its action is less decisive against plant lice and cochineals.
By suppressing the fruit-tree smut, which accompanies the invasions
of the cochineals of the olive-tree, orange-tree, rose laurel (Pastre), and
vine (Targioni-Tozzetti), it removes the greatest infliction incidental
to the parasiticism of insects. Bouillie bordelaise does not, however,
suppress the cochineal. Bouillie bordelaise is regarded by Dr.
Menudier, Mohr, and D'Angelo as sufiicient to remove the phylloxera.
D'Angelo has used this process in the island of Elba with full success.
The treatment comprised two sprayings of the stock with a bouillie
bordelaise of 1"8 per cent blue vitriol and 1 per cent lime, and three
sprayings with a 5 per cent solution of blue vitriol containing sulphur.
Bouillie bordelaise is not frequently used for the destruction of insects,
because it is not so energetic in its action as poisonous substances.
Bouillies with a Scheele's green or emerald green basis, which contain
both copper and arsenic, are preferred. Bouillie bordelaise possesses,
to a certain extent, the insecticidal properties of arsenical bouillies.
It likewise acts on the stomach of the insects which absorb it. To
intensify its action organic insecticides are added to it ; thus Martini
reports that 2 per cent bouillie bordelaise, to which 1-5 per cent of
rubinia or carbolated tobacco juice was added, instantaneously kills
cochylis of the vine. After one of these sprayings there were only
5"6i-7'87 per cent of grapes with caterpillars, whilst after a single
treatment with pure bouillie bordelaise, there were still 2i per cent.

CHAPTER XV.

... CELEBTE-COPPEB ^^^10^^^^ BOB.TE-COPPEK

02 Eau Celeste.-Preparation.-By dissolving a copper salt
in water and treating the solution with an excess of ammonia a pa e
eel ;tl blue precip'itate of copper hydrate ^orms then an mt
PPlp^tial blue solution. Eau celeste is an ammonmret of copper oxiae
d?s:red m wlter. Audoynaud, who ^.-^^^-sed thi^liquc.^^^^^^^^^^^^^^^
bouillie bordelaise in the struggle agams cryptogamic diseases pre
^RrPd eau celeste by dissolving 10 lb. of blue vitriol m 3 gallons of hot
Tater cooling he solution, th?n adding about U gallons ot commercial
rmmonr Ihe concentrated eau celeste th.. obtained keeps m-
definitely When required for use it is diluted with 200 gallons ot
wate Bellot des Mhiieres advised for the preparation of eau celeste
Tnotier method of manufacture, that of Schweizer's capro-ammoniacal
Uquor which is endowed with the remarkable faculty of ^isso ving cellu-
or This method is based on the property of ^--^o^-. ^^'^f ^^J^^
metallic copper m presence of air, producing -P-^^Xof'^^" BauiS
A funnel is filled with red copper turnings, and ammonia of 2 J Baume
noured on the top. The ammonia is passed and repassed seveial times
oveithe copper.^ The solution is not finished until after a great many
nlssac^es With 1 lb. of copper 15 gallons of anticryptogamic liquor is
Sufed To distinguish it"^ from the eau celeste of Audoynaud, this
sdut^on is termed "Bellot des Minieres ammoniaco- cupric liquor, or
?°mm nSte of copper". Copper -bonate likewise dis^olves^m
ammonia, and the blue solution so obtained dissolves eel ulose like
Schweizer's hquor, whilst, on the contrary, ^be ammonimet o coppe^^
hvdrate prepared from the sulphate nitrate, or the phosphate of copper,
fs not ;ndowed with this special property. The -anticryptogamic
quo obtained by dissolving copper carbonate m ammonia is called
eau celeste raodifik or ammoniacal carbonate of copper bomU e^^
preparation is moie simple than that of any other coppei bo mllie for t
suffi'ces to weigh a certain quantity of commercial c^PP-' ^^bo^^^^^^^
It up with the necessary water, and add ammonia to «o"\Pl«^^^°\^
tion^ The same result is obtained by adding ^--^^^ ^ ° ^^^^^^^
hnnrpni-nonne until it is converted into a deep limpid blue hquor. in
Am Srrcustomary to dilute ammonia to 26" B. -th sev.n o eigh
times it weight of water, and to add copper ^^^^ib^^^-^e whi t stiumg u^
a small amount remains insoluble-a P^'ooi ^hat the iquoi d^^^^
contain an excess of ammonia, a condition ^^b-h is no attended to m
the greatest number of instances. If it be desired to piepaie moditied

(261)

262 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

eau celeste from blue vitriol, Mohr's process is followed : Dissolve 3 lb.
of blue vitriol in hot water and add gradually, after cooling the solution,
1 lb. of soda ash, then 12 fl. oz. of ammonia of 24° B. ; dilute the blue
liquor to 100 gallons. The same liquor is obtained by adding sodium
carbonate to ordinary eau celeste or in mixing a solution of 1 lb. of blue
vitriol in 50 gallons of water, with 2 lb. of ammonium carb nate in 50
gallons of water. Liquoi's with an ammoniuret of oxide of copper
basis thus vary greatly, both as to strength and method of m mufacture.
When they are prepared it must not be forgotten that dry carbonate of
copper contains 51 per cent of copper, whilst blue vitriol which crystal-
lizes with 5 molecules of water, only contains 25 per cent. So that a
bouillie may have the same copper content twice as much blue vitriol
must be taken as copper carbonate. A bouillie bordelaise said to be
a 1 per cent boujllie, that is, made with 1 lb. of blue vitriol to 10 gallons
of water, ought to be compared in its cryptogamic action with a 1 per
cent ordinary eau celeste, and with a 0*5 per cent modified eau celeste
made from copper carbonate, these bouillies containing the same dose
of metallic copper.

Properties. — Compared with bouillies eaux celestes have the great
advantage of being limpid solutions, containing neither precipitate nor
deposit capable of choking the spraying machines, or of being deposited
at the bottom of tanks or vessels. Eau celeste is more easily used than
bouillie bordelaise, the more so as it is made a long time beforehand in
a concentrated condition and can be kept indefinitely in that state.
Formerly, bouillie boixlelaise contained a large excess of lime, which
rendered its application exceedingly difficult. Eau celeste had proper-
ties which had to be considered and which gave it a real advantage.
At that already distant time 0'5 per cent eau celeste ran much cheaper
than 2-3 per cent bouillie bordelaise. Eau celeste could also be more
uniformly distributed than thick bouillie. Finally, the adherence of
the thin pellicle of copper hydrate, which is formed after the evaporation
of the ammonia from the surface of the organs covered with liquor, is
much more perfect than that left by bouillie bordelaise, and resists, ac-
cording to Eossel, rains of seven to eight hours' duration. All these
advantages were of a nature greatly to encourage the use of eau celeste
at a time when bouillie bordelaise was not sufficiently studied. Now
it is otherwise. Carefully prepared, bouillie bordelaise does not now
contain an excess of lime ; it has no more than 0-5-1-0 per cent of
blue vitriol, and thus no longer has the great drawbacks of the original
bouillie bordelaise, so that all the comparative advantages of eau
celeste have almost disappeared. The advocates of eau celeste,
especially the ammoniaco-cupric liquor, and the modified eau celeste,
assert that eau celeste of this special composition is more active than
bouillie bordelaise, because it dissolves cellulose, and would thus, by
contact with the organs, disintegivate them and destroy them much
quicker than ordinary cupric bouillies. This opinion is very much
open to question. If it really were so, it would be easy to determine
the superiority of inolitiod eau celeste and any other analogous prepara-
tion endowed with th(5 extraordinary })ropertiesof Schweizer's reagent of
dissolving cellulose. In opposition to this enticing theory there must

EAU CELESTE.

26ii

first be placed the results of the comparative trials made with cupric
anticryptogamics not endowed with this property, such as bouillie
bordelaise and bouiUie bourguignonne. They do not establish practically
the sporicidal superiority of eau celeste. Millardet and Gayon obT-
tained the following results : —

TABLE LI. — Showing the Effect of Spraying Vines tvith Eau Celeste, on the
Density of the Wort, the Weight of the Wort per Kilogramme of Grapes,
the Stigar Co?itent per Litre' of the Wort, and the Weight of the Grapes.

^.

^

-KS

CO

r^

Weight of

-1

g tc

s.^

Wort per

Vines.

Method of Treatment.

Kilogramme

of Grapes
in Grammes.

CO -z

^

Marcin

Three times with ammoniate

1-060

66 '-8

120

76

„

Twice with bouillie bordelaise

1-070

719-6

178-5

120

Malbec

Three times with ammoniate

1-083

739

208

142

"

Twice with bouillie bordelaise

1-088

755

213-5

148

Secondly, highly dilute solutions of these cupric compounds do not
dissolve cellulose unless after long maceration, and moreover, thirdly,
the organic matter of which the cells of fungi consist is not cellulose,
but an analogous substance which has not the same reactions as
cellulose. Even if it be admitted that the liquor of Bellot des Minieres
can dissolve spores in contact with the solution, the method of applica-
tion is against these properties being exercised. Sprayings, in fact,
spread a thin layer of this liquor on the surface of the leaves ; the
ammonia evaporates forthwith, and there remains on the leaves in-
soluble cupric hydrate, with no solvent action on cellulose. The
solvent action of this liquor only lasts a very short time, which would
enable it to act curatively at the moment it is projected on to the
diseased organs. The application of these preparations in the full
evolution of mildew has produced immediate curative effects, which
would plead in favour of a special action of which bouillie bordelaise
and bouillie bourguignonne are deprived, but it is know^n that blue
vitriol solutions exercise to the same extent a curative action on this
disease. Solutions of copper hydrate in ammonia or in other alkalies
have quite peculiar properties. Thus Bellot des Minieres' preparation
of a certain strength, like eau celeste modifiee, dissolves cellulose, and
a solution of 5 parts of blue vitriol in 100 parts of water, added to
5 parts of glycerin and a sufficiency of caustic potash to redissolve the
precipitate first formed and give an azure solution, possesses the re-
markable property of dissolving natural silk. From there to the con-
clusion that this preparation should be the most perfect insecticide is
but a step, since it can dissolve the shell of the insect, the composition
of which is very analogous to that of silk. This insecticide, which has
not yet been tested in actual practice, would only decompose very
slowly, and might act energetically on insects. [Mouillefert has found

264 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

that ammoniacal sulphate of copper, although more active agiinst
phylloxera than blue vitriol, does not kill it, and Pearson reports that
eau caleste removes the Macrodactyliis subspi)iosiis injurious to rose
bushes.] Along with all these properties just described eau celeste
has grave drawbacks. It is, above all, blamed for causing serious
barns, especially when the treatment has to be applied very early.
This fact is especially to be dreaded when eau celeste is spread in
moist weather when it therefore dries slowly on the leaves ; on the
other hand, when the sprayings are applied in the strong heat of
summer, this defect entirely disappears, and eau celeste is in every
way advantageous. These burns, in fact, are easily explained. It
has been seen under blue vitriol that the poisonous action of cupric
preparations on plants was the more pronounced the more soluble
they were in water. Eau celeste contains a cupric compound, as
soluble as blue vitriol, and the effect produced at the moment of
sprayiug is thus equally unfavourable to the plant. It is likewise
admitted that blue vitriol is poisonous, owiag to the sulphuric acid
which it contains, and which, in bouillie bordelaise, is fixed and
rendered harmless by the lime. Although sulphuric acid may con-
tribute to a certain extent to the corrosive action of blue vitriol, it is
not the chief poisoning principle. For the same reason it is generally
admitted that eau celeste burns the leaves, because the sulphuric acid
of the blue vitriol used in its preparation is fixed by the ammonia, and
that this unstable salt, in decomposing, liberates sulphuric acid, which
then burns the leaves. This hypothesis is one of the chief reasons of
the use of copper carbonate in place of blue vitriol in the preparation
of eau celeste ; the latter, in fact, burns the plants much less than
ordinary eau celeste.

There is thus great analogy between the action of blue vitriol and
eau celeste, both on the plants and on the fungi to be overcome.
From the beginning of the use of eau celeste it was to be seen that a
solution made from 0'5 per cent of blue vitriol sufficed to produce the
desired effect ; the doses have diminished in certain cases as far as
O'l per cent of blue vitz-iol. With such solutions burns are no longer
to be feared. In contrast to blue vitriol, which, as it dries on the
surface of the leaf, forms small crystals, which dissolving in the dew
yield concentrated solutions, burning the leaves where these crystals
are accumulated, the eau celeste deposits cupric hydrate on evapora-
tion. The defect of burning the leaves only exists for the eau celeste
for the time during which the sheet of liquid takes to dry. As soon
as dry the ammonia which holds the copper oxide in solution evapo-
rates, leav.ng a residue of cupric hydrate, which covei's the surface
of the leaf and protects it against spores. If rain falls it is only
beneficial, because far from dissolving or detaching the cupric film,
it only dissolves and removes the sulphate of ammonia, the action of
which on the plant may be injurious. Eau celeste, compared with
blue vitriol solutions, therefore, possesses the advantage of leaving an
adherent deposit on the surface of the leaf, and whilst equally
efficacious at the moment of use, has a much more durable action.
With an equal dose of blue vitriol, it requires fewer sprayings with

EAU CELESTE. 265

eau celeste than pure blue vitriol, which renders this treatment less
costly than those in use. There is, ho%Yever, a third cause, which
explains the poisonous action of eau celeste on plants. Whether pre-
pared with or without an excess of ammonia the eau celeste, in drying',
disengages ammonia on the surface of the organs attacked, and in
greater quantity the greater the excess of ammonia. Now, ammonia
is injurious to plants ; as soon as the air contains a doze exceeding 70
milligrammes per cubic metre of air, it causes burns already described.
To replace bouillie bordelaise with advantage eau celeste should not
be made from more than 0"o per cent of blue vitriol or 0'2o per cent
of copper carbonate nor with an excess of ammonia. To be certain
that an excess of ammonia has not been used it is well only to add
such an amount as will not entirely re-dissolve the precipitated copper
hydrate. The chances of burning are thus much diminished. Be-
sides, it is well only to use eau celeste in fine dry weather, so as to let
the thin layer of liquid spread on the surface of the plant. To get an
eau celeste free from sulphate of ammonia this liquor is prepared as
follows (Prillieux) : Precipitate the blue vitriol as cupric hydrate w^ith
half the quantity of ammonia used in making eau celeste ; let this
celestial blue precipitate deposit ; decant the clear limpid supernatant'
liquid, which contains all the sulphate of ammonia ; add water equal
in volume to the bulk of the liquid removed, and add the remainder
•of the ammonia to dissolve the precipitate ; an eau celeste is thus ob-
tained which contains little or no sulphate of ammonia. The same result
is obtained by adding to a 0"5 per cent bouillie bordelaise the ammonia
required to dissolve the precipitated cupric hydrate, then decanting
the dark blue supernatant limpid liquid after some time from the
deposit formed by the excess of lime and sulphate of lime. This eau
•celeste no longer contains traces of sulphuric acid nor of sulphate. By
taking these .precautions in the preparation of eau celeste, and only
usiag it rationally, this liquor is excellent, and especially cheap. A
■drawback of eau celeste is that it leaves no decisive mark on the
leaves. Eau celeste is especially advised to combat cryptogamic
■diseases in full evolution in circumstances where the use of bouillie
bordelaise would have no effect. In such cases its special properties,
its energetic action on the conidiophores and on spores, produce the
best results. Its corrosive action on the leaves in the dose required to
stop the first attack of fungi in the spring, will always cause it to be
inferior to neutral bouillie bordelaise, but in summer, when burns are
not to be feared, the second and third treatments for the year are
advantageously made with eau celeste.

Eau celeste is, therefore, in the hands of the cultivator, a poicerful
■agent for overcoming cryptogamic diseases in full evolution, whilst
bouillie bordelaise is par excellence the preventive remedy tvhich should
protect the plant, by killing the germs which are dejjosited on its sur-
face.

Use. — The use of eau celeste has found numerous advocates in
France and Switzerland. Eau celeste modifiee basin America in many
•cases replaced bouillie bordelaise.

Phytophthora infestans, De By. (potato disease). — Mohr advises to

266 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

overcome this disease in full evolution, 3 lb. blue vitriol, 1 lb. 80-85
per cent soda ash, and 12 fl. oz. of ammonia of 24° B. in 10 gallons of
water. Spraying is done in the morning as soon as the dew has
evaporated. A dilute solution, used in July, will not burn the leaves.

Peronospora viticola, DeBy. (mildew of vine).^ — -Eau celeste affords
cheap summer treatment, especially to stop a sudden outbreak. Mohr
advises for June spraying an eau celeste prepared thus : Dissolve 14- lb.
of blue vitriol in 2 gallons of water, add first 8 fl. oz. of ammonia, 24° B.,
then the solution of 'i lb. of 80 per cent soda ash, and make up to IQ
gallons. July and August sprayings are made with an eau celeste con-
sisting of 2 lb. of blue vitriol, 9'6 fl. oz. of ammonia, 12 oz. of calcined
sola, and 10 gallons of water. In the opinion of several observers a 0'4
per cent eau celeste suffices. Prillieux doubts its efl&cacy and prefers-
a stronger eau celeste to produce an effect on the disease in full evolu-
tion and an advantage over bouillie bordelaise. Kalas' results with
bouillie bordelaise are in a general way better than those obtained
with eau celeste. Vines strongly attacked by mildew are greener
after treatment with bouillie bordelaise than after eau celeste.

Peronospora gangliformis, De By. (lettuce disease). — Kitchen
gardens often have to suffer from this disease. It would be pre-
vented, according to Prof. Maxime Cornu, by covering the soil with
a layer of shavings or straw, previously impregnated with eau celeste.
Dung from mushroom beds ought to be drenched with eau celeste,
then drained, before being used for lettuces.

Piiccinia graminis, Pers. (rust of wheat). — Galloway has examined
the effect of eau celeste on the evolution of rust, and made the in-
teresting remark that winter wheat, treated every ten days by spraying
with eau celeste, is completely freed from rust, whilst it remained
attacked when the sprayings were at twenty days' interval. In this
last case the diminution of diseased plants was only 33J per cent.
These results were disputed by Swingle.

Puccinia Pruni, Pers. (plum leaf rust). — Pierce reports that this
rust is successfully overcome by an eau celeste of blue vitriol 1 lb.,
ammonia 26° B. 12 fl. oz., carbonate of soda 1^ lb., in 100 litres of
water.

Podosphcera Oxycanlhce, D. C. — Pammel reports that he prevents
the fall of the leaves incidental to this disease by ten sprayings, from
6 June to 4 August, on grafted cherry-trees and Mahaleb plums
with eau celeste modifiee. The thirty-five plants treated had 4498
leaves against 1195 on the untreated samples.

Sphcerotheca Huviuli, Burr, (strawberry blight). — Humphrey ob-
tained a complete cure of attacked plants and a recrudescence of verdure
by treatment with bouillie bordelaise containing 0-4 per cent of car-
bonate of copper and 2 per cent of carbonate of ammonia.

Guignardia Bidxvelli, V. and R. (black rot of grapes). — Galloway
got goo I results by the following ti-eatment : Modified eau celeste,
containing O'l per cent of copper carbonate dissolved in ammonia and
used in four sprayings, 30 April, 15 May, 30 May, and 14 June. The
total of the diseased grapes was reduced to 0"6 per cent, against 45 per
cent on the untreated stocks.

EAU CELESTE. 267

TABLE LII. — Shoiving Composition of Gallotvaifs Eau Celeste.

Blue vitriol . . . . . . . 3 lb.

Soda crystals . . . . . . H ,,

Ammonia ....... 2:^ ,,

Water 100 gals.

Galloway's boiiillie applied in six sprayings in fine weather, in eight
sprayings at fifteen days' interval in bad weather, was still more active.

TABLE LIII. — Shoiving the Percentage of Sou7id Grapes on Untreated Vines,
and on Vines Treated by Eau Celeste made by Two Different Formulce.

Percentage of
Sound Grapes.
Untreated vines ........ 38-3

Vines treated by eau celeste, formula I . . . . 91"32

„ II. . . . 98-06

Gloe sporium frutigemim, Berk, (bitter rot of apples). — Goff and
Nijpels state that three sprayings with eau celeste is a sufficient
protection for apples.

Fusicladmm dentricum, Fuckel (apple scab). — Galloway and Goff
caused this disease to disappear entirely with four sprayings of eau
celeste containing 45 grammes of copper carbonate dissolved in
ammonia per 100 litres of water [45 parts by weight in 100,000
parts by measure]. It is necessary to make the first spraying before
blossoming, the second immediately after blossoming, and the two
last at fifteen days' interval.

Fusidadimn pirinuvi, Fuckel (pear scab). — These are overcome in
the same way (Mohr).

Entomosporium maculatum, Lev. (leaf scald of the pear-tree). —
This disease may be removed by spraying with an eau celeste modifiec
containing copper carbonate 1 lb., ammonia 26° B.. f lb., water 100
gallons. To prevent burning the leaves an excess of ammonia must
be avoided. Pammel recommends as many as eight sprayings, 8, 20,
and 27 June, 9, 11, 18 and 21 July, and the last 1 August.

CoUetotrichum Lindemuthianum, Br. and C. (anttaracnosis of the
haricot, etc.). — According to Halsted, modified eau celeste acts better
than bouillie bordelaise against this disease. In Canada a peculiar
system of disinfecting seed haricot beans is used. It is an eau celeste
containing about 1 per cent copper carbonate dissolved in the neces-
sary amount of ammonia. The results obtained by one hour's disin-
fection are as follows : —

TABLE LIV. — Sliowing the Result of Disi?ifecting Haricot Bean Seed ivith

Eau Celeste.

Percentage of Healthy Pods,

Plants Reared. Per Cent.

Disinfected haricots .... 73 79

Untreated „ . . . . 84 43

Cercospora circumcissa, Sacc. (" shothole fungus," spots of the leaf
of the plum-tree and almond-tree). — Galloway reports that an eau
celeste containing 1-42 lb. of copper carbonate dissolved in 204 gallons
of water and the necessary ammonia may be used against disease of
the peach and almond trees, because it scarcely burns the leaves. To

268 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

overcome the Cercosjwra a first treatment is given as soon as the leaves
appear, the second ten days later, and a third at fifteen days' interval.
Pierce thus obtained 80-98 per cent of healthy leaves against 2-8 per
cent on the untreated.

^^Cercospora ayigulata, Wint. (spots of the leaves of the gooseberry).,
— Pammel got good results by seven sprayings made between 6 June
and 15 August.

Septoria Bubi, West, (spots of the leaf of the bramble and rasp-
berry bushes). — Whilst the raspberry is sensitive to the action of eau
celeste, good results are obtained if it is used to combat the Septoria
of the bramble. Goff obtained the following results: —

TABLE LV. — Showing the Effect of Spraying Bramble Bushes with Eau

Celeste.

Kind of Crop.

First Series,
lb. of ^ Fruit.

Second Series,
lb. of Fruit.

Brambles Bprayed six times
„ untreated .

224

168

488
452

Gladiosporium fulvtim, Cooke (tomato leaf rust). — Jenkins and
Britton found that modified eau celeste had no good effect, whilst
bouillie bordelaise entirely removed this disease.

Lemon Warts. — Swingle and Weber advise modified eau celeste to
prevent lemon warts. For this purpose they advise the first treatment
after the fall of the petals, the second two or three weeks later, the
third after the fall of the last flowers, and the fourth when the fruits
are the size of a pea. In moist weather favourable to the extension
of the disease, it is necessary to multiply the treatments.

93. Phosphate of Copper, CuHPO^. — Preparation. — By adding
a solution of phosphate of soda to a solution of blue vitriol.

Use. — Fairchild prepared a bouillie by precipitating 4 lb. of blue
vitriol by 7 lb. of phosphate of soda, and made the bulk up to 100
gallons. This preparation whilst having the properties of bouillie
bordelaise, covered the leaves better than that preparation. In the
treatment of Entomospor inm 77iaculatmn, Lev. (leaf scald of the pear-
tree), the bouillie gave good results ; it did not seem to damage the
leaves. The results obtained by Galloway against the rusts of oats
and wheat wez'e not remarkable. The plots treated 6, 16, and 20
June, as well as July, showed no rust, but the yield in grain was only
83 per cent of the usual yield.

94. Borate of Copper, CuB^O-. — Preparation. — By adding a
solution of 50 grammes of borax to a solution of 25 grammes of blue
vitriol.

Use. — Copper borate has been recommended by [jodemann; as an
antiseptic, and anticryptogamic preparation with the properties of
copper salts and of borax. Fairchild used it in a bouilhe of 4 lb. of
blue vitriol and 4*3 lb. of borax in 100 gallons of water to destroy
Entomosporium mamdattim (spots of the leaves of the pear-tree). This

COPPER FERROCYANIDE. 269

bouillie adheres better than ammoniacal bouillie bourguignonne.
Galloway treated sunimer wheat and oats against rust by making four
sprayings with this bouillie, 6, 16, and 20 June, and 5 July. He
obtained plots of wheat with no rust, and yielding 9 units of grain"
against 8'5 on the untreated plots. With a bouillie containing more
borax — it consisted of 70 grammes of blue vitriol and 180 grammes of
borax in 100 litres of water— he obtained on winter wheat fields free
from rust by spraying every ten days.

95. Ferrocyanide of Copper. — Preparation. — By adding a solu-
tion of yellow prussiate of potash to one of blue vitriol, until all the
copper is precipitated.

Use. — Galloway tried to overcome the rust of winter wheat by
spraying the wheat fields every ten days with this preparation. He
used a bouillie of 7 oz. of blue vitriol and 16 oz. of yellow prussiate
in 621 gallons of water. By this treatment he diminished the
diseased plants 30 per cent. A bouillie consisting of 4 oz. of blue
vitriol and 6 oz. of yellow prussiate used in four sprayings, 6, 16, and
20 June, and 5 July, has considerably increased the yield of summer
wheat and oats. If fell to 7 units against 8'5 on untreated plots.

CHAPTEE XVI.

COPPER ACETO-ARSENITE (EMERALD GREEN, PARIS GREEN)— COPPER
ARSENITE (SCHEELE'S GREEN)— COPPER SILICATE— COPPER CAR-
BONATE—BOUILLIE BORDELAISE CELESTE— VEHDIGRIS COPPER
ACETATE— VARIOUS BOUILLIES.

96. Aceto-Arsenite of Copper, Emerald Green, Paris Green.
— -Definition. — ^The aceto-arsenite of copper sold in commerce under
the name of [emerald green], "Paris Green,"' " Schveinfurth green,"
is a double arsenite and acetate of copper.

Preparation. — By dissolving 4 lb. of white arsenic in 5 gallons of
water, and on the other hand, 5 lb. of verdigris in 5 gallons of water,
and mixing the two liquids. The mixture is boiled for some time,
then a little acetic acid is added. To prepare a bouillie, it suffices to
mix 1 lb. of emerald green in a little water, add milk of lime contain-
ing 1 per cent of quicklime, and make up the paste to 10 gallons of
bouillie. Tnis mixture of cupric hydrate [acetate] and arsenite is much
used in America. Commercial emerald green contains 55-34:-60-16
per cent of arsenic (As^,03) and 27"7-30-9 per cent of cupric oxide (CuO).

Properties. — Commercial aceto-arsenite of copper is not com-
pletely msoluble in water, and thus possesses an injurious action on
the plants treated. This defect disappears if the acetate of copper be
converted into hydrate by quicklime, by mixing the emerald green with
lime. Aceto-arsenite of copper freshly prepared is a precipitate fine
enough to remain suspended in water. That is not so with the
emerald greea of commerce. If a bouillie be prepared from the latter,
as is generally done, the granular precipitate falls to the bottom of the
liquid, and it is necessary to use a sprayer fitted with an agitator to
distribute the salt regularly on the trees. Trials by Lintner to de-
termine whether arsenites mixed with soil were absorbed by plants led
to the conclusion that plants only absorb arsenites with great diffi-
culty, and only in cases where it is placed in large doses in direct con-
tact with their roots. The aerial organs do not dissolve insoluble
arsenites deposited on them by spraying. The ash of potato plants, which
has been sprayed with a bouillie of arsenite of copper, does not con-
tain arsenic. Baily obtained the same results with peach-trees treated
with emerald green, and Fletcher on apple-trees similarly treated.
Scheale's green being insoluble behaves like arsenite of lime. When
the product is pure, that is to say, when it contains no unconverted
arsenite of soda, its action on plants in insecticidal doses is, so to speak,
7iil, and in many cases it may be employed in 0 05 and O'l per cent
bouillie. On the other hand, the action of Paris green makes itself
felt very energetically when it is not mixed with lime. Baily found that

(270)

COPPER ACETO-ARSENITE. 271

it is less injurious when very finely divided. Whitehead gives as harm-
less doses, 40 grammes in 100 litres of water for apple-treis, 45
grammes in 100 litres of water for pear-trees and gooseberry bushes,
and 60 grammes in 100 litres of water for plum-trees and currant
bushes. (For grammes per 100 litres read also parts by weight per
100,000 parts by measure.)

Peach-trees are the most sensitive to copper arsenites ; that is not
surprising, since other and even insoluble copper salts, even in minimum
doses, induce the total or partial fall of the leaves of that tree.

Action of Arsenites of Copper on Insects. — The arsenite and
aceto-arsenite of copper are violent poisons to all insects, which in
nibbling the leaves absorb a small quantity.

Use. — Arsenical insecticides have been in use since 1859. In 1872
Dr. Le Baron recommended the use of Paris green against the cater-
pillar of the citigrade spider. In 1878 Haynes tried this product
against the pyrahs of the apple-tree, and this trial was followed by
those of Cook, Forbes, Alvood, and others. In 1887 the use of
arsenical salts was recognized as the most efficient treatment for
phytophagous insects. In 1896, 2000 tons of emerald green were
consumed in America and 100 tons in Canada. Arsenical sprayings
now rarely consist of arsenites alone ; they are mixed with substances
which facilitate their application by keeping the arsenites in suspension
in water or impart to them anticryptogamic properties. The substances
with which they are mixed should be of such a nature as not to render
the arsenites soluble ; thus ammonia eau celeste, pure blue vitriol, soap,
and ferric chloride are excluded. A mixture highly valued in America
is that of emerald green and bouillie bordelaise. Coquillet advises to
increase the adherence by the addition of resins rendered soluble by
soda. For the same purpose 2 per cent of molasses may be incorpor-
ated or 1 per cent of farina (potato starch). This latter substance has
also the advantage of maintaining the precipitate of arsenite of copper
longer in suspension in the liquid. Petrol presents no advantage.

Method of Use. — 1. In the Dry State. — Insoluble arsenites are
used in the dry state as powder w^hen the want of water renders
spraying the arsenites as bouillies impracticable. To prepare an in-
secticidal powder 1 lb. of Scheele's green is mixed with 100 lb. of
gypsum, 100 lb. of slaked lime, or 67 lb. of fariaa, or with mixtures of
50 lb. of gypsimi and 50 lb. of farina, or with 67 lb. of farina and 33
lb. of gypsum. Dry treatment can only be applied to small-sized
plants owing to the danger to the opei'ator. It is ver}' much used in
America against the insects of the cotton plant, and various altises,
cabbage caterpillars, etc. The insecticide is not so evenly distributed
in the form of powder as it is as bouillies ; it is done with bellows,
hand, or sieve. The operator spreads it whilst walking backwards
against the wind. Calm weather is chosen early in the morning when
the plants are covered with dew or moistened by rain.

2. As Bouillies. — Arsenites of copper are used as bouillies chiefly
in arboriculture. It is preferable to precipitate the arsenite of copper
on the spot by mixing arsenite of soda and blue vitriol with the addi-
tion of a little lime rather than make commercial Scheele's green or

272 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

emerald green into a paste. A finely divided precipitate is thus
obtained which keeps in suspension and allows the insecticide to be
evenly distributed. The best all-round proportions are 0'08 per cent
of copper arsenite and 0'08 per cent of lime (8 lb. per 1000 gals.).
From 3-5 hectolitres of this bouillie are sprayed per hectare (26-4-44
gallons per acre). Spraying should be done in dry weather without
dew and renewed if rain washes the leaves before the insecticide has
acted, that is to say, within twenty-four hours. In arboriculture, to
obtain the object in view it is necessary to make three to six sprayings
per annum. These shoidd be made at epochs determined by the habits
of the insect to be overcome.

Precautions. — By an order of 1846 the use of arsenites
for the destruction of insects was forbidden in France. But in
spite of that injunction, owing to the success obtained in America
with these insecticides, their use has extended in France. Arsenites
are true poisons which should be guarded against ; however, by operat-
ing with precaution the treatment ceases to be dangerous. But the
operator, after the operation, should wash himself conscientiously,
face and hands, and brush his clothes. He should never forget
that he is working with a poison. It has been objected, and still is
objected in France, that their use on vegetables and on fruits is a
danger to the public health. However, in America, where this treat-
ment is practised everywhere no case of poisoning has been reported.
The Americans have seriously examined this drawback and made
numerous analyses of fruit and vegetables treated with arsenite, but
found that the poison does not enter into the plant treated, and that
remaining on the surface completely disappears after twenty to twenty-
four days. The amount of arsenic spread on plants is so minimum
that if they were consumed even shortly after treatment it would re-
quire an exceptionally large quantity to produce a poisonous effect.
From the analysis of the cabbages treated, Gillette calculated that a
person would require to eat 28 heads in a single meal to feel the
symptoms of poisoning. In the same way, Eiley from experiments made
on potatoes so treated, calculated that one would require to eat several
26 gallon barrels to be poisoned. Three weeks after the first treatment
Fletcher by analysis found no trace of arsenic on the apples. Plants
intended for consumption do not therefore present any danger to the con-
sumer after that lapse of time. However, if such treatment be applied
in hot countries prudence must be exercised, for the absence of summer
rains might render the presence of this poison on the edible parts of
the plant dangerous. Moreover, its use must be avoided during
flowering, for the bees and insects indispensable to the fertilization of
the flowers risk being killed ; further, practice has shown that flowers
are rendered sterile if this treatment is applied at the time of
blossoming.

Arsenical treatment is excellent when applied on vegetables which
are not to be consumed immediately and in countries where frequent
rains remove all trace of the poison.

The profit is considerable, for no treatment is more advantageous
to the plant. The following figures published in America refer to

COPPEE ACETO-ARSENITE. 273

orchards only. During the ten years previous, the quantity of apples
which without the treatment became wormy was calculated as 50-75
per cent of the total crop. It is estimated that the plus value was 4s.
to 10s. per barrel of 26*4 gallons, with an expense of 5d. per tree.-
From amongst several the case of a Virginia orchard is quoted of
which one-third was subjected to the arsenical treatment, whilst the
other two-thirds remained untreated. In the treated portion the
amount of healthy fruit exceeded by 50 per cent that of the untreated
portion, and by 100 per cent as regards market value. The loss
suffered under this heading by the two-thirds of the orchard untreated
was valued at £500. These figures so eloquent plead in favour of
this simple, economical, and efficient treatment which will meet one
day in France with the same success which it already has in America
and Norway.

Use ag'ainst Injurious Fungi. — Fusicladiiim dentriticum, Fuckel
(apple scab). — By treating apple-trees with emerald green, against
injurious insects, apple scab is, likewise, and to a great extent, dimin-
ished. Goff obtained 50 per cent of immaculate apples against 30 per
cent on untreated trees with four sprayings of 0"06 per cent bouillie
of emerald green neutralized by milk of lime. Galloway states that
0*05 per cent bouillie with a little lime is superior to all other
products.

Phytophthora infestans, De By. (potato disease). — Galloway greatly
recommends to combat simultaneously both the potato disease and
the Colorado beetle a bouillie consisting of 100 litres of bouillie borde-
laise with 4-10 grammes of emerald green (that is, 4-10 parts of
emerald gi-een by weight to 100,000 parts by measure).

Use against Injurious Insects. — The injurious insects com-
bated in America by this process are very numerous, and will now be
enumerated, describing only those which ravage European plants and
those of America which are of particular interest, because they may
eventually prove dangerous to our crops.

Anthonovius Pomorum (apple weevil). — The cleaning of the trunk of
the tree and its branches and coating with lime bouillie bordelaise or
with acidified green vitriol are treatments capable of destroying the in-
sect in its winter shelter. Spraying with copper arsenite a little before
flowering and during the summer may poison and destroy the adult
insects which escape the winter treatment. The results of this method
are perfect (Debray). Goethe does not share this opinion.

Anthonomns Grandis, Boh. (cotton weevil). — F. W. Maly advises
spraying with copper arsenite bouillie to destroy this weevil, the larvae
of which and the perfect insects destroy the cotton- flowers.

Zabbrus Gibbus, F. (Zabre bossu). — An arsenical spraying at the
right time kills these larvae.

Crioceris Asparagl (the asparagus beetle). — Vivien recommends for
the destruction of the perfect insects and their larvie sprayings with a
bouillie prepared thus : Mix a solution of 2 lb, of blue vitriol in 8
gallons of water with 0'4 gallon of a concentrated solution of sodium
arsenite of 15° B. ; then add the requisite amount of carbonate of
soda to alkaline reaction (it takes about \ lb.) ; then it is again acidulated

18

274 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

whilst adding J^ of a lb. of blue vitriol. The bouillie is made up to 10
gallons.

Altises. — These multiple generations of small voracious insects,
numerous species of which exist, may be combated by copper arsenites
in powder or bouillie.

Haltica ampelojihacja, Guer. (altise of the vine, vine louse, Piicerotte).
— Galliot's bouillie, the composition of which is given under the head-
ing " Arsenite of Copper " (p. 276), and which is nothing but a bouillie
bordelaise containing a little Scheele's green, must be used in this
case, yet the same result is obtained by simply adding emerald green
to a cupric bouillie.

Psylliodes affinis, Payk. (altise of the potato). — As an efficient
method of destroying fungi spores and insects, such as the dryophora
and the altise of the potato, Woods recommends bouillies consisting
of a mixture of 120 parts of emerald green in 1000 parts of bouillie
bordelaise, or 120 parts of emerald green and 750 parts of lime in
100 parts of water.

Haltica Chalyhea (plum altise). — Britton states that ai'senical
bouillies destroy this altise. The perfect insects are destroyed by
0-2 per cent and the larvae by a 0-06 per cent bouillie.

Cassida nebidosa. — In Saxony the arsenical bouillie has proved
itself more efficient than such insecticides as soapy emulsions of
petroleum, vinegar, slaked lime in powder.

Sil'pJia, L. — Opaque silph of the beet.

Siljiha atrata (black silph). — Silphs like the dryophora of the
potato are killed by cupro-arsenical bouillies with an emerald green
-or Scheele's green basis.

Treatment by Powders.— An intimate mixture of 1 kilogramme
(2-2 lb.) in 100 kilogrammes (220 lb.) of very finely divided gypsum,
• damaged flour, ashes, or a mixture of these different substances, is
spread by hand on the dew-charged leaves. This dose suffices for 1
hectare (2^ acres). The operator must so manoeuvre as to have the
wind behind him.

Treatment with Bouillies. — There is distributed, preferably by
the spraying machine "Eclair," a bouillie of 0"2-0-24 per cent of
Scheele's green, or 0-5 per cent of lime and 0'2 per cent of emerald
green. Four hectolitres of bouillie per hectare are applied, say 35
.gallons per acre. Gaillot's bouillie has been tried with success in the
North ot France, and in Herault the larvae die in twenty-four hours,
f^orauer advises the use of a bouillie of 1 per cent Scheele's green and
0"2 per cent of flour. Grosjean, Debray, and Hollrung have aided in
popularizing this efficient method.

Leptinotarsa decenilineata (Colorado beetle). — In America cupro-
arsenical bouillies have been used with success for many years against
this voracious insect. This treatment has the advantage of destroying
many other insects at the same time and of protecting the plant against
potato disease, PhyloplUhora hifestans, De By.

Galeruca calmariensia (galeruque of the elm). — In the U.S.A.
arsenical bouillies are used to destroy the larvae of this chrysomelide,
which rapidly causes the death of the finest avenue trees. But

COPPER ACETO-ARSEXITE. 275

p;i'jantic spraying machines and powerful pumps mounted on trucks
are required, capable of throwing a jet to the top of the tallest trees.

Epilachna or Coccinella globosa, 111., is destroyed by spraying
emerald green in powder on the plants (Sajo). Likewise —

Agriotes lineatus, L. (wire-worm) ; Entomoscelis adonidis, Pall.

Waevils. — Stift advises spraying the ravaged plants.

Scolytes. — Fletcher advises coating the tree with oil paint contain-
ing emerald green.

CJiaetocnema tibialis, 111. — This altise, injurious to _ beets in
Hungary, may be destroyed by 0-185 per cent emerald green (Gemesi).

Cleonus sulcirostris, L. — This beetle, injurious to beets, may be
overcome by 0-5-2 per cent emerald green bouillie. The first spraying
ought to be done as soon as the leaves appear, the second at the time
the insects copulate, say near end of May.

Solenopsii geminatus. — This ant, which does much damage to the
young shoots of peach and plum trees, may be combated by spraying
with bouillie bordelaise containing 0-05 per cent of emerald green and
4-5 per cent of molasses.

The larvae of the Tenthredos (saw-flies) are successfully overcome
by cupro-arsenical bouillies.

Xematiis Bibis, Scop, (gooseberry saw^-fly). — This insect is success-
fully overcome m Canada, likewnse X. Pallidiventris.

Eriocampa adumhrata (cherry-tree saw-fly). — Coquillet successfully
used a cupro-arsenical bouillie rendered adherent hy the addition of
pine resin dissolved in potash.

It is easy to destroy caterpillars by spraying with cupro-arsenical
bouillie, for these insects are then the victims of their voracity. The
butterflies most injurious to arboriculture which have been treated
most successfully belong to the Tortricides, to the Pyralides, and to
the Tmeides.

Carpocaj)sa pomoneUa fcoldlin moth). — The damage caused by
this pyralis is considerable. Action must be taken to destroy it very
soon after the hatching of the caterpillar, for it lives on the leaves
until the apples are big enough to be penetrated. The first spraying
should be made after the fall of the flower, and the second a week
later, before the calyx is re-closed and the fruit reversed on the stem'.
Spraying during flowering must be avoided, for it would destroy the
insects which fertilize the flowers, and render the litter barren. ^

Carpocapsa funebrana (pyralis of the plum-tree). -Spraying with
cupro-arsenical bouillie made at the moment of the fall of the corolla
of the flowers and on the young tied fruit poisons the grubs before
they can pierce inside the frui .

Hyponomeulavialmclla, Jell (small ermine moth of the apple-tree).
— Emerald green sprayings are in general use in certain countries.

Agrotis segetum (common dart moth). — To prevent the damage
caused by this voracious grub, which is called the grey-worm, it
suffices to make a cupro-arsenical spraying; on the young spring shoots
threatened. It is not a case of beet crops alone which have been pro-

1 Translator's Note. — Spraying during flowering courts risk of enclosing poison
in core of apple.

276 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

tected in the North of France and in Heraulfc, but also the gardens
which in the spring time suffer much from the hibernating cater-
pillars of the Noctiia which attach themselves to the young shoots, and
cut the stems of small plants. They escape search and sight, because
they hide during the day, and only commit their I'avages at night.
Fletcher, the Canadian Government entomologist, advises for the de-
struction of grey-worm the use of a mixture of bran and emerald
green. The wheat bran which is used in the mixture is previously
moistened and sugared, then spx-ead between the rows of transplanted
plants. As soon as the poison is on the soil, the plants are not
attacked by the grubs, which take themselves off rapidly, or die of
eating it.

Gheimatohia briimata, L. (winter moth, Evesham moth). — The grub
of this butterfly, which is particularly injurious in the spring to the
buds of apple-trees, pear-trees and plum-trees, is overcome by cupro-
arsenical bouillies sprayed on the buds and the young shoots. This
process used for a long time in America, and recommended by Eiley,
has been popularized in France by Prof. Debray of Alger, and Gros-
jean, inspector-general of agricultural education.

Pieris BapcB, L., Pieris BrassiccB (white cabbage butterfly). — Cupro-
arsenical bouillie, spread on the cabbages, is generally used to destroy
the caterpillars. The rains suffice to wash the cabbages and render
them fit tor food.

Hadena Brassica (noctua of the cabbage). — A mixture of gypsum
and emerald green dusted on the cabbages gives good results.

Leucania Unijninctata, Haw. — Fletcher advises to sprinkle
meadows with a mixture of 1 lb. of emerald green and 25 lb. of
farina.

Acari. — Amongst the phytoptides may be quoted Eriojihyes Bibis,
Nal., or Phytoptus Bibis. In America it is overcome by spraying with
0*06 per cent emerald green, 0'12 per cent of wheat starch or soft
soap. The first spraying is made in spring, the second in autumn
shortly after the fall of the leaf to prevent the acari from taking
shelter in the buds.

97. Copper Arsenite, Cu.^As.Oj,. — Preparation. — By precipitat-
ing a solution of arsenite of soda by a solution of blue vitriol. The
green precipitate which forms, filtered, washed and dried, is known
as Scheele's green. To prepare an insecticidal and anticryptogamie
bouillie Gaillot recommends to dissolve 1 lb. of white arsenic and 1
lb. of soda ash in a gallon of boiling water and then to add with con-
stant stirring a solution of 10 lb. of blue vitriol in 10 gallons of
water. There is then added a milk of lime, made from 10 lb. of
lime and 10 gallons of water, then a solution of 20 lb. of molasses in
2 gallons of water ; the whole is then diluted to make 100 gallons of
bouillie which is nothing less than a bouillie bordelaise containing a
little Scheele's green.

Properties. — Scheele's green is insoluble in water; when it is
freshly prepared the precipitate is so fine that it remains a long time
suspended in the liquor, which is not the case with the dry commercial
product.

r

COPPER CARBONATE. 277

Use. — It is used under the same conditions as emerald s^'een.

98. Silicate of Copper, CuSiOy. — Preparation. — Dissolve 4 lb.
of blue vitriol in 50 gallons of water, and add after cooling whilst
stirring a solution of 12;^ lb. of silicate of soda in 50 gallons of water..
A gelatinous precipitate, insoluble in water, is formed.

Properties. — Copper silicate was prepared by Fairchild, with the
object of obtaining a more adherent cupric bouillie than bouillie
bordelaise. He, however, found, contrary to his expectations, that this
bouillie did not adhere so well as normal bouillie bordelaise. Copper
silicate, less soluble than copper hydrate, cannot perform the same
services as the latter, and although the silicate of soda used in its
preparation is endowed with antiseptic properties, the insoluble
product which it forms with copper is, owing to its insolubility, an
inert body.

Use. — Fairchild used the silicate of copper bouillie against
Entomosporium maculatum, Lev. (leaf scald of the pear-tree), and
found that it did not damage the leaves of the tree. That is not
surprising, as only soluble cupric salts and their derivatives are poison-
ous to plants.

99. Carbonate of Copper, CuCOg (bouillie bourguignonne). —
Preparation. — By adding a solution of a copper salt to a solution
of carbonate of soda. To convert 1 kilogramme of blue vitriol,
CuSOjoHoO, into carbonate of copper, it requires theoretically 453
grammes of drv sodium carbonate or 1146 grammes of soda crvstals,
Na.,C03lOH,0.'

CuSO^ + Na.,C03 = NaoSO, + CuCO,

Copper JSodium = Sodium Copper

sulphate. carbonate. sulphate. carbonate.

The bouillie bourguignonne designed by Masson to overcome
parisitic fungi is merely carbonate of copper suspended in a given
amount of liquid. It is prepared thus : (1) Dissolve 20 lb. of blue
vitriol in 5-6 gallons of hot water, and add thereto after cooling a
solution of 8|-9 lb. of soda ash or 23 lb. of soda crystals, and dilute
the whole to 100 gallons with water. (2) Dissolve each compound in
50 gallons of water and mis the solutions as cold as possible at the
time of use. The second bouillie is better than the first. To obtain
a quite neuti'al bouillie soda ash must be used, for soda crystals, which
normally contain 62 '8 per cent of water, are efflorescent, and a neutral
bouillie cannot be prepared from them without groping in the dark.
Moreover, they always contain larger or smaller quantities of sulphate
of soda. The limpid liquid which separates from the blue precipitate
after the bouillie has settled should neither be acid nor alkaline ; if
blue litmus paper dipped in the liquid turns red, carbonate of soda
must be added ; if red litmus paper turns blue, blue vitriol must be
added.

Properties. — -Carbonate of copper is insoluble in water but soluble
in organic acids. The deposit formed on the leaves by spraying with
bouillie bourguignonne may become soluble as the cupric hydrate of
the bouillie bordelaise and eau celeste, or by the juices transpired

278 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

by plants, or by water containing carbonate of ammonia or carbonic
acid. The amount dissolved being very small, the plant is never in
contact with a poisonous amount of soluble copper salt, and bouillie
bourgaignonne does not burn, except when prepared with a great
excess, or with an insufficient amount of carbonate of soda. In making
bouillie bourguignonne, not more than 2 kilogrammes of blue vitriol
should be used. This quantity is already very strong, and as was the
case in other bouillies it has been reduced in modern bouillie bourguig-
nonne to 0"3 per cent. Carbonate of copper freshly prepared by
mixing cold solutions of the ingredients is gelatinous, and it is pre-
ferably in this form that it should be spread on the leaves to get the
maximum adhei'ence and produce the best effect ; as it does not
preserve this gelatinous condit'on long, the bouillie must be used
immediately after it is made. In fact aftei' eight to ten hours copper
carbonate becomes granular, and ends by being converted into a heavy,
sandy precipitate, and thus the bouillie loses a portion of its good
qualities. This conversion would appear to be accelerated by an
excess of carbonate of soda. It already happens when 2-6 kilo-
grammes of soda crystals are used for 2 kilogrammes of blue vitriol,
whilst with 2*3 kilograms, the theoretical amount required, this
conversion does not occur until after twenty-four hours. Many
bouillies are thus intentionally made with a small excess of blue
vitriol, which cannot injure the plant, and which strengthens slightly
its action on fungi. If bouillie bourguignonne be made hot, the
resulting carbonate of copper is granular and crystalline. Its anti-
cryptogamic action is perceptibly mferior to that of gelatinous copper
carbonate. A bouillie is often used prepared with 04 per cent of
blue vitriol and 0 4 per cent of soda crystals, or even 0*3 per cent of
blue vitriol with the same amount of soda crystals. Commercial
copper carbonate always granular, though excellent to prepare
modified eau celeste, is unsuitable for the preparation of a normal
bouillie bourguignonne. If nevertheless it is to be used, it must first
of all be reduced to the state of paste by means of a little water,
adding thereto whilst stirring the rest of the water, keeping the
bouillie generally more concentrated than those obtained by pre-
cipitation from blue vitriol. The adherence of this bouillie is much
less than that of bouillie bourguignonne prepared from blue vitriol.
Gerard, Muyssen, and Leplae consider gelatinous carbonate of copper
adheres better than cupric hydrate, and the duration of the action
longer than that of bouillie bordelaise. This difference was especially
marked when the bouillie bordelaise contained a great excess of lime.
However the adherence of a neutral bouillie bordelaise may now be
considered as great as that of a normal bouillie bourguignonne.

Use. — Its ready preparation, its uniform composition, its good
adherence, its great fluidity not obstructing the spraying machines,
have greatly helped to popularize Masson's bouillie, and it has met
with a general reception, especially in Germany and in America. It
may be used with an ecjual l)lue vitriol content, wherever bouillie
bordelaise gives good results. It is especially recommended in certain
cases. Weiss regards it as superior in the disinfection of purchased

VEEDIGEIS COPPER ACETATE. 279

onions and tubers, which by steeping for one to two hours in a 1 per
cent bouillie are disinfected. A twenty-four hours' steep does not
injure them. Fairchild points out the remarkable results obtained in
the struggle against Entomo's'pormm maculatum, Lev. (leaf scald of.
the pear-tree). Its action is surprising on the larvae of the goose-
berry saw-fly {Nematus ribis, Scop). To destroy it as soon as the
false caterpillar appears, a spray is applied of 2-5 per cent of blue
vitriol and 2-5 per cent of carbonate of soda. In less than an hour the
larvje die, blacken, fall, and its ravages are stopped.

loo. Bouillie Bordelaise Celeste. — This bouillie is a mixture of
insoluble copper carbonate and soluble bicarbonate.

Preparation. — Dissolve 1 kilogram of blue vitriol in a few litres
of hot water, and add after cooling 870 grammes of carbonate of soda,
then dilute to 100 litres. A proportion of 90 per cent of copper is
precipitated as insoluble carbonate, and the remaining 10 per cent of
copper is converted into soluble bicarbonate. This small amount of
dissolved copper is not enough to cause the bouillie to burn the
trees, but it suffices to impart to the bouillie the anticrvptogamic
properties of eau celeste. Bouillie bordelaise celeste, recommended by
Fery, combines the properties of the anticrvptogamic bouillie bour-
guignonne and eau celeste. It is one of the best anticryptogamic
bouillies.

loi. Basic Acetate of Copper. — Definition. — Commercial verdi-
gris consists largely of basic acetate of copper.

Preparation. — The verdigris industry is localized in the South of
France. Le Verdet extra sec en grains, of interest here, because of its
more uniform composition, is made throughout the whole of Lower
Languedoc as follows. The method of manufacture consists in cor-
roding sheet copper by the acid marc of grapes. The marc is chosen
as rich in alcohol as possible. It is preserved before use in vats,
where it is strongly compressed without access of air. The sheets of
copper used weigh about 100 grammes (say 3^ oz.), are 6 centi-
metres (say 2^ inches) wide, 16 centimetres (say 6^ inches) long, and 1
millimetre {^^ inch) thick. When the marc is to be used, it is taken
from the vats and air admitted to convert the alcohol into vinegar or
acetic acid. The fermentation which ensues raises the heat to
40° C. (104° F.). When the alcohol of the marc is converted into
acetic acid, a little vinegar is added to strengthen its action if it be in-
sufficient, then it is put in contact with copper. New copper
smooth surface only being attacked difficultly, the sheets under<
preparation which consists in rubbing them with a pad dipped
verdigris acidulated with vinegar. After drying them in the sun, they
are submitted to a temperature of 60°-70° C, which greatly facilitates
the first attack. They are then brought quite hot and arranged in
layers on the marc, spi-ead out on the ground of a special spot ; a layer
of marc is spread on them, a fresh layer of copper sheets, and so on
until the mass rises 1 metre above the ground. Under the influence
of the heat the acetic acid attacks the copper sheets. After six to
eight days the marc bleaches ; it is exhausted. The green layer formed
on the plates is not yet verdigris. To finish the operation the plates

: It be in-
;r with ^
ndergo a\
lipped in ^

280 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

are laid on supports in a stove heated to 30° C. After twenty-four
hours the supports are dipped into water at SC^ C. (86" F.), where
they remain four to five days. This steeping is repeated five to six
times. The green crust of verdigris has then dissolved the copper and
formed a blue mass of basic acetate of copper. It suffices to scrape
this crust, which is commercial verdigris. It comes to market in two
forms : (1) As a product containing no moisture, and termed Verdet gris
extra sec, containing 34-35 per cent of copper. (2) As a still moist
product, containing 25-42 per cent of water, and termed Verdet gris
sec merchand. The latter being of varialjle composition, and as buyers
must have a definite product, it is the Verdet gris extra sec which is
used in the preparation of the bouillie. It is sold as balls, cakes, or
grains. To prepare the bouillie, it sufiices to crush the verdigris, mix
it with a little water, macerate it for some days, and then dilute it to a
suitable consistency.

Properties. — Verdigris is amorphous. But it swells in a little
water after a few hours ; forming a viscous paste beaten up with much
■water dibasic acetate of copper splits up into soluble copper acetate
and insoluble cupric hydrate, which forms a blue flaky precipitate with
the properties of bouillie bordelaise. Bencker believes this precipitate
remains flaky for a longer time, and thus keeps itself suspended longer
than bouillie bordelaise. The verdigris bouillie has the properties of
bouillie bordelaise and blue vitriol. The deposit of hydrated oxide of
copper which it contains covers the leaf with a protective layer of
insoluble copper oxide, and the solution of copper acetate acts like
solutions of all soluble copper salts in an immediate and very energetic
manner on the spores of fungi as well as on the plant itself. This
soluble portion of the verdigris copper acetate would in fact produce
burns if care were not taken to use sufficiently dilute bouillies. Now
the dose of soluble copper acetate present in a verdigris bouillie is not
sufficient in most casss to corrode the organs touched by spraying, and
plants suffer comparatively little by this treatment. However, plants
sensitive to dilute solutions of blue vitriol and to cupric hydrate deposited
on the surface of their leaves will, after spraying with this bouillie, be
poisoned to the same extent and suffer the same damage, followed by
partial and even total fall of the leaves, as is the case with ordinary
peaches and certain species of rose bushes. Bencker, Girard, Chuard,
and Porchet found that the adherence of the cupric hydrate of the verdi-
gris bouillie issupei-ior to that of other bouillies. It mustnot be forgotten,
however, that the cupi-ic hydrates behave in the same manner in all
l^ouill es if these are prepared and used rationally. If bouillie borde-
laise formerly adhered badly, compared with bouillies with a verdigi'is
basis, it is not the case now with bouillie bordelaise used immediately
after its preparation. A neutral bouillie bordelaise, a bouillie borde-
laise celeste, can celeste modifiee, vei-digris bouillie, and Ferret's bouillie
have many analogies to each other. Their adherence, so to S})eak, is
the same, and their anticryjjtogamic enei'gy almost identical. Cai'eful
study of this point has shown that the tendency of copper salts to
poison ])lants as well as their antici'yptogamic energy is perceptibly
Ijroportionate to their copper content. The action is inversely pro-

VEEDIGEIS COPPER ACETATE. 281

portional to the molecular weight of the copper compound contained
in a given amount of liquid, and the rapidity of the action is propor-
tional to the degree of solubility of the copper compound. The weak
acid or alkaline reaction of these preparations has no secondary
■curative effect. Verdigris bouillie must, therefore, be prepared with
a weaker dose of verdigris than that of the blue vitriol, which enters
into the composition of bouillie bordelaise, firstly because blue vitriol
■only contains 25 per cent of metallic copper, whilst verdigris contains
35 per cent ; secondly because verdigris is ]3artially soluble in water.
The dose of 1-5 per cent is not exceeded in bouillies, it is mostly
lower than this and descends to 0-1 per cent. Verdigris bouillie has
the same drawback as blue vitriol and eau celeste. It leaves no
"visible mark on the plants, and renders the control of the work of the
■operator difficult. To obviate this drawback, Chuard and Porchet
add potter's clay, china clay, carbonate of magnesia, gypsum, or chalk.
It is, moreover, comparatively dearer than other copper preparations
■of equal copper content, which is an obstacle to its becoming popular.

Use. — Verdigris has been used as an anticryptogamic in France
since 1890, and in America since 1892.

Peronospora viticola, De By. (mildew of the grape). — In virtue of
the energy and adherence of verdigris, three treatments suffice (Bencker).
The first fifteen days to three weeks after the issue of the first leaves
with a 1-5 per cent bouillie, 2 hectolitres per hectare (17'6 gallons per
acre) suffice. If the invasion of mildew be very great, supplementary
treatments with 0'35 per cent of verdigris are required. Cuboni ad-
Tocates this treatment.

Gupjuardia Bidwelli, V. and E. (black rot of grapes). — Galloway
with six sprayings with 0-1 per cent verdigris bouillie obtained 90-47
per cent of sound grapes against 19'06 per cent on untreated vines.
-According to experiments by Kathay and Havelka, the spores of
Guignardia are killed after twenty minutes by steeping in 05 per cent
bouillie. Linhart got the same results with copper acetate. Eougier
recommends Viala and Pacottet's bouillie consisting of neutral copper
■acetate 1 lb., acetic acid 8 fluid oz., water 10 gallons.

Puccinia (rust). — Galloway got interesting results by spraying a
field of gi'ain four times, on 6, 16, and 25 June, and 5 July ; with a
0-3 per cent bouillie he entirely prevented rust. The uredospores of
Puccinia coronata wex-e prevented from germinating by 1*0 per cent
bouillie (Hitchcock and Carleton).

Entomosporium maculatum, Lev. (leaf scald of the pear-tree). —
Halsted found that 0-2 per cent bouillie suffices to overcome this
parasite, and Fairchild advocates verdigris as the best preparation
against spots of the leaves of the pear-tree.

PItytophthora infestans, De By. (potato disease). — Whilst Pearson
found verdigris as energetic as bouillie bordelaise, Sturgis found it
without action on Phytophthora Phascoli (Lima bean mildew).

Rot of Grapes. — Consecutive attacks of Cochylis. These are pre-
vented, according to Vermorel, if the grapes are sprayed with verdigris.

I02. Copper Acetate, Cu(C.^H.p.J'-HyO. — Preparation. — Neutral
•copper acetate, or crystallized verdigris, is obtained : (1) By treating

282 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

copper turnings by acetic acid until complete solution is effected.
(2) By double decomposition between blue vitriol and lead acetate.

CuSO, + PbfCgHgO,)'- = Cu(C,H,0,)2 + PbSO,

Copper Lead acetate. Copper Lead

sulphate. acetate. sulphate.

Properties. — Copper acetate forms greenish-blue crystals with a
molecule of water of crystallization. These crystals contain 31 per
cent of metallic copper. They are completely soluble in five times
their weight of boiling water at 15° C. Used to overcome cryptogamic
diseases copper acetate behaves like blue vitriol, and in general, like
all soluble copper salts, that is to say, it is poisonous to plants, whilst
at the same time it acts very energetically on parasitic fungi. However,
this action is ephemeral, because cupric acetate decomposes on the
surface of the leaves into a basic acetate behaving like copper hydrate.
Used in Italy at 1 per cent against Leaf Curl of Peach it caused, like all
other copper preparations, the total fall of the leaves and the fruit
treated (Brioni). A 0'5 per cent solution of cupric acetate destroys the
germinative power of the spores of Guignardia Bidicelli in twenty
minutes, whilst 0'5 per cent of blue vitriol takes thirty minutes to pro-
duce this effect. Its action on the spores of this fungi is therefore re-
latively identical with that of blue vitriol, for copper acetate contains
31 per cent of metallic copper, whilst blue vitriol only contains 25 per
cent. The action of copper acetate lasts longer than that of blue
vitriol. Chuard and Duserre found that this was due to the neutral
acetate being converted on the leaves into an insoluble, very adherent
derivative.

Use. — Copper acetate has been used in Italy and Switzerland
especially against mildew, Peronospora viticola, De By., in 0'5-0'8 per
cent doses. It is sometimes used in France in the last treatment of the
vine, so as not to soil the grapes, and avoid introducing sulphuric acid
into the wort or any other substance capable of changing the quality
of the wine. Copper acetate is, so to speak, abandoned to-day and re-
placed by the copper bouillies in the struggle against parasitic fungi,
for it has no advantage over the latter preparations and it is a little
more costly in use.

1 02a. Perret's Bouillie is a bouillie bordelaise containing a por-
tion of its hydrated oxide of copper in solution as cupric saccharate.

Preparation. — By mixing, in a certain ox'der, a solution of blue
vitriol and sugar with milk of lime. Ferret, the inventor, pi'epares it
as follows : J3eat up 20 lb. of quicklime after slaking with 80 gallons
of water, and whilst stirring constantly add this milk of lime to 1 lb.
of sugar in 10 gallons of water; then run this mixture of lime and
saccharate of lime mto a solution of 20 lb. of blue vitriol in 100 gallons
of water. It is essential that the copper solution be cold. Frillieux
advises that care be taken to see that the bouillie is slightly alkaline.
Barth, in 1896, advised the preparation of cupric saccharate bouillie
thus : Dissolve 20 11). of blue vitriol in 40 gallons of water, and after
cooling run in a solution of 3 lb. of sugar or 5 lb. of 50 per cent
molasses in 30 gallons of water, then a milk of lime with l,i lb. oi

VEEDIGEIS COPPER ACETATE. 283

quicklime ov 2 kilograms of slaked lime and 30 gallons of water.
The necessary dose of sugar may also be added to the bouillie bordelaise.
The action of bouillies of this composition is excellent. Later on, the
addition of more sugar was advocated. Peglion proposed f lb. for
1^ lb. of blue vitriol and Petermann 4 lb. of molasses for 2 lb. of
blue vitriol and i lb. of lime. The increase in the sugar must be
regarded as injurious to the quality of the bouillie, and it throws
discredit on a preparation which, after this change in its composition,
lost the masterly qualities imparted to it by Perret and Barth. The
amount of copper may be brought to the proportions now used in
bouillie bordelaise, say 0"5-l per cent of blue vitriol, but the dose of
sugar, which should never exceed 15 per cent of the blue vitriol used,
must also be reduced. Perret's bouillie is a bluish-green liquor with
cupric hydrate and sulphate of lime in suspension. The sugar which
enters into the bouillie prepared by Perret's and by Earth's processes
is not enough to convert the whole of the blue vitriol used into
saccharate. The 1-3 lb. added to the bouillie cannot convert more
than l-l:-4"2 lb. of blue vitriol into saccharate. The saccharated
bouillie contains, therefore, 0"ll:-0"42 per cent of soluble copper.
Perret remarked that by adding sugar to bouillie bordelaise it became
more adherent to the leaves than simple bouillie bordelaise, and that
its anticryptogamic action was increased owing to the soluble copper
salts which it contained.

Barth was the most zealous advocate of this bouillie which he
regarded as the best, as the ideal bouillie. It never burned the leaves,
and its adherence was surprisingly perfect. This last property was due
to the cupric saccharate being assimilated without injurv by the plant,
which would so far render it immune to cryptogamic diseases. This
opinion has been greatly disputed. It has been shown besides that the
plant had no need to absorb large amounts of soluble copper derivatives,
but on the contrary, the strong doses absorbed after the use of soluble
copper salts always injures the health of the plant. Infinitesimal doses
of copper sufiice to give to the plant greater resistance against parasitic
fungi, and if that infinitesimal amount is not directly assimilable, it is
rendered so by the juices transpired by the leaves. It is possible,
however, that cupric saccharate, an organic derivative of copper, may
be directly assimilable by the plant, and that this property may be such
as to give it a plus value as a stimulating bouillie. This bouillie,
however, cannot have a superior anticryptogamic action to other
bouillies, for a bouillie can never act as a destructive agent of the
organs of fungi which are distributed in the interior of plants. Its
object is to damage the exterior organs of fructification, annihilate the
spores, and prevent their dissemination. This end is perfectly attained
by bouillie bordelaise. Perret's bouillie was a gi-eat improvement on
the primitive bouillie bordelaise, when the latter had not the energy
nor the adherence of the present bouillies, owing to defects in its
composition. But Perret's bouillie now is perceptibly the same as
bouillie bordelaise, or such preparations as verdigris bouillies, which
along with cupric hydrate contain a certain amount of soluble copper.
Girard, agreeing with Gindt and Sendersens, regards Perret's bouillie

1284 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

as being more adherent. Other observers declare the contrary, but it
has been generally observed that Ferret's bouillie communicates a
greener tint to the foliage and a more prolonged one than other
bouillies. Galloway advocates adding to bouillie bourguignonne a
•certain dose of sugar, and has used vpith success a mixture of blue
vitriol 3 lb., soda crystals 3^ lb., molasses 3 lb. in 10 gallons of
water. Whilst causing burns on the leaves of the vine this bouillie,
Tised against black rot, brought the percentage of sound grapes from
46 per cent on the untreated vines to 98"51 per cent. For a sucrated
bouillie not to cause burns, the amounts of sugar indicated by Ferret
and by Barth should not be appreciably exceeded, for with larger
doses of sugar the whole of the copper is transformed into soluble
cupric saccharate which behaves like solutions of copper acetate.
Bee-keepers have protested against the use of Ferret's bouillie, under
the pretext that bees by collecting copper saccharate on the surface of
the treated leaves are poisoned, and may convey into the honey an
■element injurious to human health. It took long and careful experi-
ments by E. Jacky in 1900 to prove the want of foundation of their
•complaints, and to demonstrate that if bees are very fond of sugar
and molasses, they shun and do not absorb these sweets when they
•contain copper.

Use. — After a general infatuation for Ferret's bouillie, at the time
when Michel Ferret recommended it as a substitute for bouillie borde-
laise, which then possessed many defects, this preparation fell into
oblivion. The chief reason, as pointed out by Dr. Cazeneuve, is that
the composition of the bouillie bordelaise has been so modified that as
far as its action is concerned it cannot be compared with the primitive
bouillie. By substituting molasses for sugar aiid by greatly increasing
the dose. Ferret's bouillie has been converted into a solution of cupric
saccharate. As this bouillie contains large quantities of soluble copper,
its contact with the plant becomes deadly to it. Its adherence is less
and it does not stand rain. Ferret's bouillie may be used in all cases
"where bouillie bordelaise gives good results. However, Barth found
it superior in the struggle against mildew. Nijpels found it better
against Phytophthora infestans, DeBy., when applied in two sprayings
annually. Sorauer prefers it against Asteroma radiosum, Fr., of the
rose-bush and to prevent the fall of the leaves of this shrub, due to
the parasiticism of a rust known as Phragmidiicm snhcorticuvi, Wint.

Against Alternaria Brassiere f. nigrescens, Fegl. (roasting of the
leaves of the melon) it is better than bouillie bordelaise and it appears
to act on Botri/tis cinerea, Fers. [Sclerotina Fuckeliana, De By.] (grey
rot of the vine) (Nijpels).

I02b, Various Bouillies. — As soon as the active principle of the
cupric bouillies was definitively established efforts were made to fix the
cupric hydrate and copper carbonate which they contain in a more
durable manner on the leaves. Everything which cements and binds
was incoiporated therein, milk, albumen, glue, soaps, oils, and resins.
However, the action of these binders on copper derivatives is not,
as may be supposed, purely mechanical. These sul)stances often act
chemically. Most of them form insoluble derivatives with copper.

VERDIGEIS COPPER ACETATE. 285-

capable, it is true, if they are used inamediately after their preparation,
of depositing on the leaves a copper peUicle, a true varnish which
will I'esist the weather indefinitely. But the thin pellicle which covers
the leaf may in the end, as shown by Galloway, stop the physiological
functions of the organs covered and injure the normal evolution of the
plant ; and these copper derivatives, insoluble in the atmospheric agents-
as well as in the exudation of plants, have lost, if not all, at least the
greater part of their anticryptogamic power. Under such conditions
they cannot, therefore, form like cupric hydrate an insuperable barrier
to the spores deposited on the leaves. Parasitic fungi are very often
seen to develop normally on leaves and fruit covered with a layer
of these copper varnishes. The effect of the greater part of these new^
bouillies is, therefore, quite illusory. However, their quality depends
greatly on their composition. When the amount of binders prescribed
to render a bouillie adherent are not sufficient to convert the whole
of the cupric hydrate into an insoluble binding organic derivative, that,
bouillie still contains the greater part of its copper under the active-
form of cupric hydrate which maintains its good anticryptogamic
properties. The binders so used may encircle the active principles of
the bouillie and retain them on the leaves and so become useful.
Trials of comparative adherence made with bouillies normally and
freshly prepared, and thus at the moment when their adherence is at
a maximum, have not always given results in favour of the new bouillies.
The advantage of using binders in the bouillies may be regarded as
problematical, for the simple bouilhes now used show the same
tenacity which may be regarded as sufficient. Still more so than in.
the case of ordinary bouillies is it necessary to use these bouillies
immediately after preparation, for the fine, flaky, organic precipitates,
which they contain in the beginning agglomerate and resinify, rapidly
encrusting the machines and preventing a uniform distribution of the
bouillie on the plants. Finally, the binders used in these bouillies.
may injure the organoleptic properties of the wine. It has been
observed after their use that the wine left something to be desired,
and the conviction was formed that it was these substances whick
passed into the wine and profoundly altered its gustative properties.

103. Albuminous Bouillies. — Preparation.— By adding to a
solution of blue vitriol bouillie bordelaise or bouillie bourguignonne a
sufficiency of an albuminous body to convert all the copper into.
copper albuminate.

104. Lactocupric Bouillie (Crouzel's). — Preparation. — Dissolve
20 lb. of blue vitriol in 10 gallons of watei', add i gallons of unboiled
milk, say about 1^ lb. of casein, stir strongly for five minutes, and run
into enough water to make 100 gallons. Skimmed milk does equally
well.

Properties. — This bouillie is acid and forms a mixture of blue
vitriol and cupric caseate ; this latter forms a precipitate insoluble in
water, the role of which is to retain by encircling them the small
crystals of blue vitriol formed by the evaporation of the bouillies on
the surface of the leaves. If burns caused by contact of blue vitriol
with plants, especially with the proportions given above, be feared, it

286 INSECTICIDES, "fungicides, and weed killees.

suffices to neutralize the acidity with copper carbonate. The bouillie
thereby becomes an albuminous bouillie bourguignonne, and contains
a mixture of carbonate and caseate of copper. Crouzel regards the
acid bouillie as the most active. Caseate of copper is comparatively
stable and remains rather long suspended in the liquid as finely
divided particles which do not choke up the machines, and cm be
p)erfect,ly distributed over the suiface of the plant. Nevertheless, it is
necessary to use this bouillie the moment it is prepared.

105. Bouillie Bordeiaise Modifiee. — This name is applied to a
bouillie to which a little skim milk has been added. Sorauer recom-
mends it against Uromyces Dianthi, Niessel (poppy rust). Cazeneuve
compared the adherence to the leaves of three albuminous bouillies,
which he made thus : —

TABLE LVI. — Comiiosition in Grammes of C^q^ro-Albwnhwus Bouillies.

Bhie vitriol .

Quicklime

Milk, 2 litres, say casein

Dried white of egg

Dried blood .

2000

1000

60

II.

2000
1000

100

III.

2000
1000

loa

The blue vitriol was dissolved in 70 litres of water, the lime slaked
and beaten up with 20 litres of water and then run into the blue
vitriol soluiion. The milk was diluted with 8 litres of water, and the
solution of albumen and prepared blood in 10 litres of water; these
solutions were finally run into the preceding mixture. The excess of
lime was used to fix the casein and the albumen as caseate and
albuminate of lime, and to preserve all its energy to the cupric hydrate
of the bouillie. The sprayings were made on 16 August, 1897,
some days before floods of rain, after which it was found that the
adherence of the lactic bouillie bordeiaise was not appreciably better
than that of the saccharated bouillie. But the spots produced by the
evaporation of the albuminous bouillie lasted to the end of the season.
Galloway added a very strong dose of glue to bouillie bourguignonne.
The composition of this bouillie was: Blue vitriol 8 lb., soda crystals
3-^ lb., glue 3^ lb., water 100 gallons. Adherence was perfect, and
the results obtained against black rot were : Untreated, 41-36 per cent
of sound grapes ; treated with ordinary bouillie bordeiaise, 86-47 per
cent ; ti'eated with the new glue containing bouillie, 100 per cent.
Unfortunately the cupric bouillie fixed on the whole surface of the
plant so far injured the vegetation that Galloway cannot, in spite of
the fine results obtained, recommend this new ])0uillie in preference
to bouillif bourguignonne.

106. Soapy Bouillies. — Attempts have been made to increase the
adherence of difl'erent bouillies, and even of eau celeste by incorpor-
ating soap or oil. Copper salts form with fatty acids derivatives
insoluble in water and cold alcohol, l)ut soluble in ether and in amylic

VEEDIGRIS COPPER ACETATE. 287

alcohol, and in ethylic alcohol in the hot state. To prepare a copper
soap an ammoniacal solution of oil is added to an ammoniacal
solution of copper hydrate. Neutralizing the excess of ammonia
by acetic acid, an insoluble apple-green precipitate is obtained
which agglomerates and resinifies quickly. The same compound
is also formed when a soap solution is added to ordinary copper
preparations. Swingle was the first in 1895 to add soap to
copper bouillJ"s in sufficient quantity to cause them to froth. He
observed that these bouillies adhered even on very smooth leaves.
Galloway, who experimented at the same time, recommended the
following soapy bouillie bordelaise : Blue vitriol 1 lb., quicklime | lb.,
soap 1 lb., in 10 gallons of water. He preferred rosin soaps to fatty
soaps. The soap solution is added to the mixture of blue vitriol and
lime, and the whole stirred until the froth persists. A soapy bouillie
bourguignonne of the following composition is also used in America :
Blue vitriol 1^ lb., soda crystals 1;^ lb., white soap ^ lb., water 10
gallons. Having observed that the properties of eau celeste were
actually increased by a little soap, and recognized that this new
preparation is one of the best existing, Fairchild became the advocate
of soapy eau celeste. When this bouillie is applied, it forms on the
surface of the leaf by evaporation of the ammonia a precipitate of
copper with the fatty acid of the soap, which owing to its sticky nature
remains a long time adherent, and retains the cupric hydrate. Soapy
eau celeste is no longer in this form so corrosive to plants, and does
not attack the leaves of fruit trees, vine trees excepted. In America
it is prepared as follows : Dissolve 400 grammes of blue vitriol in 50
litres of water, add thereto 20 cubic centimetres of ammonia of 26° B.,
and finally a solution of 1*25 kilograms of soap in 50 litres of
water. In Italy a more ammoniacal eau celeste is used, the com-
position of which is as follows : Blue vitriol -^ lb., ammonia 16-24
fluid oz., soap 3 lb., in 10 gallons of water. According to Tozetti
and Del Quercio, this eau celeste may be used more dilute. In
France, Lavergue, Guillon, and Gouirand are the champions of
soapy bouillies. They compared a soapy bouillie with the usual
bouillies, and -classified them as regards adherence thus : (A) Soapy
bouillie made from 2 per cent blue vitriol and 3 per cent of soap. (B)
Bicarbonate of cojyper bouillie made from 2 per cent blue vitriol and
8 per cent of bicarbonate of soda. (C) Copper carbonate bouillie made
from 2 per cent blue vitriol and 3 per cent of sodium carbonate. (D)
Bouillie bordelaise made from 2 per cent blue vitriol and lime to alka-
line reaction. Eau celeste made from 2 per cent blue vitriol and
ammonia to complete solution. Verdigris containing 2 per cent
verdigris. (E) Gelatinous bouillie. Bouillie bordelaise with 3 per cent
gelatine. (F) Saccharated bouillie, above bouillie with 1 per cent
molasses. (G) Neutral bouillie containing 2 per cent of neutral
acetate of copper.

Soapy bouillies being even more injured by keeping than bouillie
bourguignonne, all the above-mentioned bouillies were applied im-
mediately after preparation. An old soapy bouillie encrusts the
spraying machines. Condeminal advises a bouillie bordelaise to

288 INSECTICIDES, FUNGICIDES, AND WEED KILLERS,

which linseed oil has been added. This plays no other part than the
soap used in soapy bouillie. This bouillie is prepared as follows ::
Slake 10 lb. of recently burnt fat lime and emulsify therewith | lb.
of linseed oil, then run this mixture into a solution of 20 lb. of blue
vitriol in 50 gallons of water, and make up the bulk with enough
water to make 100 gallons. To render these bouillies insecticidal
as well as anticryptogamic, petroleum is added. A stable bouillie
is prepared as follows : To a soapy bouillie bordelaise of the following
composition, blue vitriol 1 lb., lime -k lb., soft soap 1-3 lb. or rosin
soap 7-9 lb., in 10 gallons of water, add 2-6 per cent of a petroleum and
soap emulsion, made from petroleum 2 gallons, soap 1| lb., water 1
gallon. Zacharewitcsh obtained excellent results with a petroleum
and soap bouillie against Fumago salicina and the Gydoconium olea-
ginum (fumagine of the olive-tree) which invade the olive attacked by
Lecanium olecB. The bouillie contained : Soft soap 10 lb., petroleum
4 gallons, blue vitriol 10 lb., in 100 gallons of water.

A concentrated solution of precipitated green copper soap in ether
or alcohol applied by the brush on the wounds of trees produced by
the woolly aphis covers them after drying with so adherent a cupric
pellicle that it forms a very efficacious and durable protection against
exterior destructive agents, and lets the wounds heal rapidly. Eain
does not remove this coating, which thus persists for many years.
Laborde found that Saglio bouillie, containing 3 per cent of a mixture:
of rosin soap and blue vitriol, used in the struggle against the
Eudemis and Cochylis of the vine, destroys 95 per cent of the first and
80 per cent of the second parasite.

107. Resinous Bouillie. — On the suggestion of Eosenstiel, Perraud
recommended in 1898 a resinous bouillie of the following composition :
Blue vitriol 1-2 lb., rosin ^ lb., soda crystals to alkaline reaction, in 10
gallons of water. The preparation requires some precautions, for
rosin does not dissolve in water, only in hot alkali ; 5 lb. of carbonate
of soda are dissolved in 2 gallons of water, then, after having brought,
this solution to the boil, 5 lb. of powdered rosin are added gradually,
stirring the mixture till it becomes fluid. This solution of rosin soap
is poured after cooling into a solution of 20 lb. of blue vitinol. A,
solution of carbonate of soda is added to this mixture until the bouillie
is alkaline to litmus paper and the bulk made up to 100 gallons.
This bouillie much resembles the soapy bouillie bordelaise recom-
mended in 1895 by Galloway, made by adding rosin soap to a 1 per
cent bouillie bordelaise. In this same category may be classed the
Aleppo pine galipot bouillie, recommended by Andri^ and Trabut
referred to on p. 214.

Vidal recommends against the fumagine Gapnodium (black smut)»
of the olive-tree a bouillie consisting of bouillie bordelaise 100 gallons^
spirits of turpentine 1 gallon.

CHAPTEE XVII.
MERCURIC CHLORIDE (CORROSIVE SUBLIMATE)— TIN CRYSTALS.

io8. Mercuric Chloride (Corrosive Sublimate), HgClg. — Pre=
paration. — By [dry] heating an intimate mixture of equal parts of
mercuric sulphate and common salt to which a little manganese
dioxide has been added.

Properties. — White crystalline powder of which 6'57 grammes are
soluble in 100 grammes of water at 10° C, and 53'96 grammes in 100
gi-ammes of water at 100° C. It is slightly soluble in alcohol and very
soluble in ether, which extracts it even from its aqueous solutions.
The taste of corrosive sublimate is bitter and nauseous. It is a violent
poison, which absorbed by the mouth produces considerable inflamma-
tion of the mucous membrane, even to the point of destroying it.
Corrosive sublimate possesses the pi'operty of precipitating albumen ;
it forms with it mercuric compounds soluble in an excess of albumen
and in solutions of common salt. Its powerful antiseptic action results
from this affinity for albumen. Corrosive sublimate preparations should
be made in glass or earthenware dishes, the metals decomposing it.

Action of Corrosive Sublimate on Plants. — Mercuric chloride
acts on plants like blue and green vitriols, but proportionately with
greater intensity. If the plant is placed through the roots in contact
with a certain dose of corrosive sublimate, it dies. Mouillefert found
that this dose for vines planted in 3-litre pots was 2 grammes in 250
cubic centimetres of water ; the dose of 0*5 gramme in 250 cubic
centimetres of water had no effect on the vine but killed weeds, chiefly
Mercurialis annua, Senecio vulgaris, Sonchus oleratus, Borrago offici-
nalis, Sinapis arvensis, Malva sylvestris, and Amarankis hlitum.
Trials by Mouillefert to overcome the phylloxera show that corrosive
sublimate solutions are absorbed by the roots and poison the juice.
Spraying with corrosive sublimate solutions burns the leaves ; how-
ever, a solution of 0-015 per cent does not injure orange-tree leaves
(Coquillet). Mercurial sprayings are deadly to the vine (Leon Vignon
and' J. Perraud). Dr. Cazeneuve's trials, however, tend to show that
corrosive sublimate used in 0"04-0'05 per cent does not hinder the
growth of the vine. Like green and blue vitriols an infinitesimal
dose of sublimate may stimulate vegetation instead of injuring it.
Ono has shown that this dose is O'OOIS per cent for green algae pos-
sessing chlorophyll. The pickling of the seed in a 1-2 per cent bath
of corrosive sublimate does not diminish their germinative power.
Sturgis found that the seeds of the cotton plant germinate after steeping
half an hour in a 1-2 per cent solution of sublimate.

(289) 19

290 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Action on Fungi and their Spores. — Used in a dose lower than
0"0013 per cent corrosive sublimate stimulates, according to trials
by Ono, the growth of saprophytic fungi, but at this strength parasitic
fungi cannot support it. Hitchcock and Carleton found that the uredo-
spores of Puccinia coronata and Puccinia riibigo vera, which are the
spores of the parasitic fungi most resistant to poisonous salts, were
incapable of germinating in a 0"001 solution of corrosive sublimate.
There is, according to Wuthrich, a great similarity between the action
of coiTosive sublimate on the spores of fungi and that of blue and
green vitriol. This action is, on the one hand, proportional to the
chemical equivalent of these salts, and on the other hand, these pro-
portions adhered to, corrosive sublimate is ten times stronger than blue
vitriol and 100 times stronger than green vitriol. The following are
the respective doses of these salts required to prevent the germination
of the different parasitic fungi : —

TABLE LVII. — Showing the Dose of Green and of Blue Vitriol and of Cor-
rosive Sublimate Per Cent Required to Prevent the Germination of the
Spores of Different Parasitic Fungi.

Fungi.

S'pores.

Germination

Nil.

Green

Blue

Mercuric

Vitriol.

Vitriol.

Chloride.

Phytophthora infestans

Coniclia

0-139

0-0125

0-00135

, ,

Zoospores

0-139

0-01-25

000135

Peronospora viticola .

Coniclia

0-1.S9

0-0125

000135

,,

Zoospores

0-139

0-0125

000135

Pucciuia graminis

Ureclospores

1-39

0 125

001350

, ,

Aecidiospores

0-139

00125

0-00135

Ustilago carbo

Spores

1-39

0-125

0-00135

Claviceps purpurea

Spores

13-9

0-0125

0 00135

Herzberg submitted the spores of different species of Ustilago to the
action of corrosive sublimate and found that they all behave in much
the same way, with the exception of Ustilago Jenseni, which resists a
little better. The following are the doses which prevent the germina-
tion of the spores examined : —

TABLE LVIII. — Showing the Dose of Corrosive Sublimate Per Cent Required
to Prev'.nt the (rer initiation of Sjjores of the Various Species of Ustilago,

Old Spores.

Young Spores.

Ustilago Jenseni .
,, Avennae .
,, Perennans
,, Hordei
,, Tritici

0005-0 01

0-()05-0(il

0-001-0005

0-005-0-01

0-U()5-0-01

0 005 0-01
O-OO 1-0-005
0-001 ()-005
0-OOi-O-OO.-)
0-001-0-005

MERCURIC CHLORIDE (CORROSIVE SUBLIMATE). 291

Action of Corrosive Sublimate on Insects. — Contact with
corrosive sublimate, even prolonged, has no action on insects and their
eggs ; thus the eggs of Bombi/x mori still hatch after twenty-four hours
steeping in a 1 per cent solution. Sublimate is, however, a violent
poison ; it may enter with the food of the insect into their digestive
system.

Use. — Lichens. — Waite obtained a negative result with a 1 per cent
solution.

Potato Scab, produced by a bacteria, Bolley; Potato Pox (Ehizoc-
tinia Solani), Kuhn ; Rot of the Stem of the Potato (Ehizoctinia),
Eolfs. — Bolley found that corrosive sublimate is one of the best sub-
stances to disinfect seed potatoes md safely destroy all the bacteria and
spores of parasitic fungi on the surface of these tubers. The results
obtained controlled by Sturgis, Eolfs, and Woods were excellent. This
method, in fact gave 99 per cent of healthy potatoes, whilst the infected
potatoes (the untreated) only gave 1-4 per cent, and the tubers treated
by bouillie bordelaise, 53-57 per cent. But the effect of this treatment,
like that of the others already described, is nil if the potatoes are
planted in a field already infected and manured with infected dung.
The soil should be disinfected previously, or laid down to a different
crop for several years. Potatoes are disinfected thus : They are freed
from earth and the pellicular membranes surrounding them, then
steeped for 1-^ hours in a 3 per cent solution of corrosive sublimate.
They are then washed, dried for a day, and then planted. Eolfs uses
a 094 per cent solution. Jones and Morse advise disinfection by im-
mersion for one hour in a 1 per cent steep of corrosive sublimate. Ger-
mination is normal even after steeping five hours ; after twenty-four
hours a certain injury occurs to the germinative capacity.

Bacillm tabificans, Dell. — Bacillus which invades the leaves of the
beet and produces jaundice. Delacroix found this bacillus on the seed
and obtained sure disinfection by steeping the seeds in a 2 per cent
solution of sublimate.

Peronospora viticola, De By. (mildew of i he vine).— Corrosive sub-
limate is, without doubt, a powerful anticryplogamic, which, in the
struggle against cryptogamic diseases of the vine, in general, might be
of great service if it were not so poisonous, and if it adhered better.
Cazeneuve in his trials with a mixture of excelsior verdigris 1 per cent,
and of corrosive sublimate 004 per cent, and with a solution of
mercuric chloride of O'Oo per cent, did not show in the first case any
greater categoric action than verdigris alone, but in the second case the
action was perfect. On the other hand, Kaserer obtained a perfect
result by the use of a solution containing 0-1- 0-2 per cent of sublimate
and milk of lime. The adherence of the sublimate being very bad, it
is necessary to multiply the treatments according to the frequency of
the rains if efficient protection of the plant be desired. An addition
of 0-5 per cent of starch has been tried to increase the adherence of
sublimate solutions. Corrosive sublimate is a very dangerous substance
to man, and there is no doubt that it can eventually pass, although in
small amount, from the grapes into the vine. Leon Yignon and J.
Perraud have estimated the mercury in drawn wine, pressed wine, lees

292 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

marc, and grapes from vines treated with mercury salts. It follows
from their analyses that grapes and the products of their fermenta-
tion only contain traces of mercury, without danger to the consumer.
Berthelot followed this note, presented to the Academy of Sciences, by
the following remarks : " The effects of the doses of mercury found by
the above authors on products consumed daily and in a prolonged
manner ought to be regarded as suspicious and dangerous ". It is thus
prudent and reasonable only to apply the mercurial treatment on such
organs of plants as are not consumed, or in winter applications.

Phytop]ithora infestans, De By. (potato disease). — This disease has
been circumscribed by adding corrosive sublimate to the soil. This
treatment is, however, too costly.

UstilaginecB (smut diseases). — Bolley found that the disinfection of
seed-corn against UstUago Bordeih, Pers., by corrosive sublimate gave
superior results to that done with blue vitriol, formaline, hot water, or
potassium sulphide.

UredinecB (rusts). — Sublimate has been used preventively against
the rust of cereals by Hitchcock, Carleton, and Galloway. This sub-
stance has given worse results than blue vitriol : a O'l per cent solution
has little effect, a O'Ol per cent solution is without action.

Fusarium roseum. — Mangin advises to overcome this disease
by disinfecting the soil with corrosive sublimate.

Guignardia Bidwelli, V. and E. (black rot of grapes). — The
action of corrosive sublimate on the spores of fungi has been com-
pared with that of blue vitriol, and, as has been shown, it is ten times
stronger. Some vine-growers have used sublimate in place of cupric
bouillies in the treatment of black rot. Cazaux and Quentin declare they
have obtained decisive results very superior to those obtained by cupric
bouillies. The latter obtained a perfect result on a portion of a vine-
yard, on a low, wet situation, favourable to the development of
cryptogamie diseases, and whose crop it had never been possible to
preserve entirely ; it even stopped an invasion of black rot in full evolu-
tion on the grapes. These vines were treated with four sprayings with
a 2 per cent bouillie bordelaise containing 1 per cent of sublimate. The
plots treated with pure bouillie bordelaise did not nearly give so good
a crop as those treated with the sublimate bouillie. The winter
treatment, consisting in coating the stems with a solution of sublimate,
is greatly recommended against this formidable disease.

Disinfection of Flower Seeds. — Hiltner advises steeping for two
hours in a 0"l-0'2 per cent solution to disinfect flower seed from
plantations invaded by this redoubtable fungus, or purchased from
outside. This treatment does not injure the germinative capacity of
the seed, even if the steeping lasts eight hours.

Use ajfainst Insects. — Coyichylis amhigndla, Hubn (cochylis of
the vine), Torlrix viiana (pyralis of the vine). — Barbut tried with
mediocre success solutions of corrosive sublimate to destroy cater-
pillars of butterflies. It has been remarked, however, that vines treated
against ciyptogamic diseases by mercurial bouillies no longer suffer
from th(!se caterpillars.

Aspidiotus Auranlis (cochineal of the orange-tree). — Destroyed

MEBCURIC CHLORIDE (CORROSIVE SUBLIMATE). 293

by spraying trunks and branches with a strong solution of corrosive
sublimate.

Phylloxera vastatrix, Planch, (phylloxera of the vine). — Mouillefert
showed that it took four hours' contact in a 1 per cent solution to
kill this formidable aphis. The oldest insects succumb first, the
youngest last. By dipping the extremity of a root covered with adult
and young phylloxera into a solution of sublimate, the adults, the
sucking proboscis (rostulum) of which sunk in the root continually
pumps the juice, die in an hour, whilst the larvae persist. Used on
an infested vine the results were bad. Vines stripped to a depth of
15 centimetres (6 inches) were treated with 20 gi-ammes of mercuric
chloride dissolved in 10 litres of water. After a few days the roots
examined still contained numerous living phylloxeras. Corrosive
sublimate is therefore powerless against this insect, for the physical
and chemical forces to which this salt is subjected in the soil soon
render it harmless. The same failure attended the attempt to poison
the sap by introducing into it 1 gramme of calomel (mercury proto-
chloride) in a hole, made at the base of the stock, which was closed
up forthwith (Ponsard's process, 1872). Neither had mercury bi-
sulphide (Catala's process) any action on this aphis.

Schizoneura lanigera (woolly aphis). — The use of corrosive subli-
mate sprayings in concentrated solution does not destroy this aphis.
Thiel found yer contra that an insecticide consisting of mercurial
ointment 1 lb., soft soap 7 lb., petroleum 2 lb., to which alcohol is
added at the moment of use, is one of the most aciive compositions
capable of killing all the aphides and of radically curing the apple-
trees.

Ants. — Corrosive sublimate is used to poison the bait.

Rodents. — To kill rats, balls are made from a paste of bread-
crumbs 12i 07.., butter 6 oz., sublimate or nitrate of mercury 3 oz.,
placed at the spot frequented by the rodents.

109. Tin Crystals, SnCl.,. — Preparation. — By dissolving tin in
concentrated hydrochloric acid, taking care there is an excess of tin.
The liquid heated until it marks 75° B. deposits on cooling the pro-
duct known as tin crystals.

Properties.^ — Stannous chloride is very soluble in water. If the
solution be diluted it becomes cloudy, depositing an oxychloride,
SnCl.jSnO ; tin crystals are poisonous.

Use. — Sbrozzi tried tin crystals as a substitute for blue vitriol
to overcome Peronospora viticola, De By. (mildew of the vine). He
found it was very inferior to blue vitriol and incapable of replacing it.

CHAPTEE XVIII.

DERIVATIVES OF CAKBON (CAEBON COMPOUNDS) —PRODUCTS DE-
RIVED FROM THE FATTY SERIES— PETROLEUM (BURNING OIL)—
PETROLEUM SPRAYS— PETROLEUM OIL EMULSIONS— PETHOLEUM-
SOAP EMULSIONS— PETROLEUM SPIRIT— VASELINE— ACETYLENE.

iio. Petroleum. ^ — Natural Occurrence. — Petroleum is a natural
mixture of all the formenic hydrocaibides.^ They are found together
in these mineral oils from butane, even from ethane and propane to
hexadecane. All these hydrocarbides are normal in structure without
lateral chains, as C"H-" + -. But the composition of these petroleums
is not everywhere the same. American petroleums contain, besides
saturated hydrocarbides of the formulae C"H-" + -, some non-saturated
hydrocarbides of the series C"H-", as well as a little cumene and
mesitylene. Caucasian petroleum consists of polymethylenic hydro-
carbides. Petroleum forms large subterranean sheets which constitute
naphtha (crude oil) and w^hich are wrought by means of wells.
Petroleum is found in Alsace in the departments ot Herault and Isere,
at Saint Boes in the Low'er Pyrenees, in Dauphine, etc. The origin
of these sheets [of petroleum] is due to the subterranean decomposition
of vegetable remains or to the action of water at high temperatures
on metallic carbides, such as carbide of iron, which exists in subgranitic
regions. At Smyrna petroleum issues, in fact, from granitic ground
itself, below which there cannot be deposits of coal or organic matter.

Fe,C + 2SiO, + 2H,0 = 2FeOSiO, + CH,.

Commercial Products. — In the industry the peti'oleums are
se])arated by [fractional] distillation and classed according to their
volatility thus : —

1. Pc^ro/ewm'^^/iens.— Hydrocarbides, B. P. 0°-70°C. ; D. =0-600-
0*650. Consist especially of pentane and hexane.

2. Peti-oleum spirit (commercial ligroin), B.P. 70°-120° C. ;
]). = 0-G50-0'720. Consist especially of heptane and octane.

3. Petroleum oil (buining oil, photogene), B.P. 120"-280° C. ; D. =
0-750-0-820.

4. Heavy petroleum oils, B.P. 280°-380' C. ; D. = 0-820-0-870.

5. Crude paraffin wax (paraffin scale), M.P. 30^-65' C. ; B.P.
170°-25r C. ; D. = 0-900-0-950 fiom C,;H.,,; to C,..H,.,.

6. Vaseline, unctuous, inodorous, uiioxidizable grease, ]\I.P. 30"-

^ Translntnr'n Nolc. — Known to us as the mavsh gas or juirallin scries, but
to the disciples of Berthelot as the formenic hydrociirbidea.

('».)■ n

PETROLEUM (BURNING OIL).

295

40'^ C ■ obtained by distillation of petroleum so long as it yields
volatile' compounds, then by oxidizing the residue in the open, and
filtering throu2;h animal charcoal.

Petroleum Oil or Burning Oil.— Petroleum oil or burning oil is
that fraction from crude petroleum which is most used against insects
which ravage plants. It is used as such, or in different emulsions.

Action of Petroleum on Plants.— Petroleum is very injurious
to plants. Spraving with petroleum emulsions is almost always pre-
judicial to the leaves and tender branches. The poisonous capacity
of petroleums of different compositions differ (Trott). The sensibility
of different plants is different ; whilst the cabbage stands a 5 per cent
emulsion, the vine only bears 2-5 per cent, and even that injures the
cucurbitaceEe. The action of emulsions depends greatly on their
preparation ; perfect emulsions diffused through much water do not
separate drops of petroleum, that is to say, which do not split up have
a comparatively harmless action on the leaves of plants, whilst badly
prepared emulsions, allowing the petroleum to aggregate on the same
point are in equal doses very injurious. In using petroleum to
destroy insects only perfect emulsions must be used. The prolonged
contact of petroleum on the trunk of a tree may become deadly and
must be avoided. The trunk and the branches coated, even in
winter, absorb sufficient quantities of petroleum, which if they do not
cause the death of the tree, at least so far disturb its economy as to
retard the opening of the buds in the spring. Roots are likewise
very sensitive, and the absorption of petroleum through them causes
the death of the plant; 20 cubic centimetres of petroleum spread m
4 litres of soil kill the vine, haricots, and weeds, such as Senecio and
Sonchus. A soil drenched with petroleum is no longer fertile, until
the petroleum is evaporated, but then there is produced, as after treat-
ment with carbon disulphide, a more intense vegetation resulting from
the perfect disinfection of the soil by petroleum vapours. Withelm
recommends steeping seed which it is desired to protect against
insects sixteen to twenty-four hours in pure petroleum. This pro-
loncred contact only slightly lowers the germinative capacity of the seed.
Action of Petroleum on Insects.— Petroleum acts on insects by
contact, and by its asphyxiating vapours. Contact with pure petroleum
causes the immediate death of all insects it is capable of penetrating,
even those with the hardest shells, and protects them from the insecti-
cides in aqueous solution. As an emulsion, petroleum is less energetic ;
e^ygs especially resist emulsions containing up to 30-35 per cent ot
petroleum (Smith, Lintner, Forbes), whilst 2-5-6 per cent emulsions
kill all soft-skinned insects. The poisonous action of petroleuna
vapour never manifests itself in the open air, only in a closed vessel,
or in the soil. In a closed vessel, Mouillefert destroyed the phylloxera
by placing a contaminated root for two days in a 2 -litre vessel con-
taining at the bottom 5 cubic centimetres of petroleum. In the soil
the injurious action does not occur, except at a short distance troni
the spot where the petroleum has been injected. From this point ot
view, petroleum is inferior to carbon disulphide and cannot replace it.
Use.— Burning oil has found the most varied applications in the

296 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

struggle against injurious insects, and its use is particularly general in
America, where it is the best-known insecticide. It is used some-
times in the pure state, but generally in a state of emulsion with
different substances capable of mechanically dividing it.

Use of Petroleum in the Pure State. — The action of petroleum
on insects is radical and infallible ; efforts have therefore been made
to use it preferably in this form, so as to free it definitely from
dangerous parasites, when there is no risk of destroying the plants
treated at the same time. If it did not possess such a poisonous action
on the plant it would be perfect. Unfortunately, the plant does not
without special precaution stand contact with pure petroleum, and in
spring or summer this method should only be used in exceptional
circumstances. On the other hand, it is not dangerous to plants
during the winter sleep, or as an injection in the soil some time before
planting.

Marlatt recommends its use as a spray or sponge wash in winter
on the aged part of trees for the total destruction of Kermes and
Scolytes. But it was especially recommended by Webster for the
destruction of Aspidiotus and Lccanium of fruit trees. Webster sub-
mitted his observations and his processes to the Congress of American
Phytopathologists in 1896. Smith and Alvood write thus on the use
of petroleum : —

" Petrol&um sprays may be used with impunity on all fruit trees,
even in full vegetation, by taking the following precautions. (If these
precautions be neglected there will be a loss of 90 per cent of the
trees treated) : —

" 1. Spraying should be done with an apparatus capable of reducing
this liquid into a fine fog, capable of touching the whole surface of the
plant without really moistening it. The formation of drops, which
might flow along the trunk to the roots, must be avoided. Poisoning
always occurs when the roots are drenched with petroleum.

" 2. The operation must be conducted in warm, dry weather, for
the petroleum should evaporate forthwith so as not to kill the plant.

"3. It is necessary to operate from March to September. In single
treatments September is the month chosen.

"4. Burning oil (lamp oil) must be used and not crude petroleum,
which contains insufficiently volatile ingredients.

" 5. It is well to cover the fruit buds before spraying.

" In these conditions peach-trees and plum-trees are more sensitive
than a])j)le-trees and pear-trees. The trees treated have finer shoots,
but the treatment appreciably diminishes the crop."

The repoi't of the 10th Congress of the American Entomologists
in 1898 is less enthusiastic on the use of pure petroleum. It con-
cluded, after discussion, that pure petroleum is a highly dangerous
insecticide for trees, but which may be unhesitatingly used when it is
a case of the destruction of insects as formidable as the San Jos6 louse
(Aspidiotus perniciosus) and certain kermes. In this case it must
only be used on the old wood, and in dry, warm weather, in which it
i-vaporates fortliwith.

The Congress of 1900 was altogether unfavourable to the use of

PETROLEUM SPRAYS. 297

pure petroleum, and declared against its use in arboriculture, remarking,
however, that the 25 per cent emulsions if they have not on kermes
such a radical action as pure petroleum, yet they completely destroy
them if the treatment be repeated and used regularly.

Ocneria dispar, Sch. (gypsy moth). — Petroleum is more active than
the tar generally used for the destruction of the eggs of this injurious
butterfly. The destruction of the eggs is complete ; a jet apparatus is
used to localize the action of the pure petroleum on the aggregation
of eggs alone.

Cossus ligniperda (Cossus gdte-bois) (goat moth). — Introduce
petroleum into the tunnels dug in the trunk of trees and plug with
mastic (Truelle).

Vespa (Guepe) (wasp) and Formica (Fonrmi) (ants). — Pure
petroleum is greatly recommended for the destruction of wasps' nests
vmderground. Early in the moi'ning, before the exit of the wasps,
about a glass of petroleum spirit is run into the nest through the
aperture, then the aperture is plugged, first with a pad drenched with
petroleum, then with earth so as to prevent the vapours of petroleum
from escaping. Carbon disulphide is, however, better than petroleum
spirit.

Schizoneura lankjcra, H. (woolly aphis). — Amongst the eighty-one
methods recommended in 1903 to destroy this aphis, Thiele found
that only pure petroleum, petroleum emulsion with soft soap, the
alcoholic solution of corrosive sublimate, carbon disulphide, amylic
alcohol, tar, and a mastic of lime and cow^-dung, were capable of
entirely destroying this aphis. All the other methods had only a
temporary effect.

Phylloxera vastatrix (phylloxera of the vine). — Mouillefert found
that petroleum had an immediate action on this aphis, but that its
vapours alone acted slowly. Used to overcome the phylloxera on vines
in pots the results were excellent, but there was complete loss on vines
on the large scale. The aphis still lived on stocks which received up
to 150 cubic centimetres of petroleum. Petroleum is thus much less
energetic than carbon disulphide, for its diffusion through the soil is
bad, so that it cannot act at a great distance from the spot where it
was injected. The coating of the roots, proposed in 1872, was rejected
as too dangerous to the health of the vine by the commission to
investigate the different processes recommended to overcome the phyl-
loxera. It would appear, however, that the disinfection of the vine by
petroleum is possible by steeping the roots of uplifted stocks in a
bucket filled with crude petroleum ; the stocks replanted in a soil dis-
infected with petroleum jdcld vines the health of which is perfect and
the roots of which show no more phylloxera.

Melolontha valgaris (cockchafer). — The diffusion of petroleum
through the soil is recognized as insufficient to destroy injurious
insects or their larv£e beyond a very narrow zone round the hole into
which petroleum was injected ; it was, however, found that the vapours
are disagreeable to the insects, and that these desert a field smelling of
])elroleum. Doming and Decaux utilized this property to free fields,
not only of white- worms, larvae of the cockchafer, but also grey- worms,

298 INSECTICIDES, FUNGICIDES, AND WEED KILLEKS.

caterpillars of the common dart moth, the larvae of wire-worms, the
nematodes, and the larvae of the beet carrion beetle. It suffices at the
time of tilling the ground to bury rags steeped in oil and petroleum
from the factories rather deepl}^ undergroimd.

Gryllotalpa vulgaris (mole cricket). — Gemadius advises to destroy
the grasshopper by running petroleum into the tunnels which it bores
in the ground. A '25 per cent emulsion of petroleum is as effective
as pure petroleum.

Culex pipiens (common gnat). — Two grammes of petroleum per
acre suffice to form on the surface of stagnant water a pellicular layer
which kills the gnats which live in the water. The larv^ of the
common gnat, being amongst the number, it is easy to get rid of them.

Lepus europceus, L. (hare) ; Lejnts cuntculus (labbit). — Taschenberg
points out the fact that trees treated by petroleum are resjDected by
hares and rabbits, and Hofer advises simply to stretch a cord steeped
in petroleum around the fields and gardens which it is desired to pro-
tect from these rodents.

Use of Petroleum as Emulsions. — Petroleum is divided
mechanically into infinitely small particles by mixing it mechanically
with finely divided solid substances, sand, earth, or with liquids,
aqueous solutions, milk, or oil. The concentration and the com-
position of the emulsions vary greatly. Comparatively with pure
petroleum a well-prepared petroleum emulsion, that is to say, homo-
geneous, behaves in its effects on plants and insects like a dilute solu-
tion. According to the concentration of the emulsion its capacity for
injuring the plant as well as its insecticidal properties will be diminished
or increased.

1. Petroleuvi mixed with Sand. — Perfect division of the petroleum
is obtained by mixing it with sand or earth as follows : Petroleum
1 litre, sand 4 litres (Eitzema Bos) ; petroleum 1 litre, sand 40 litres
(Husson). It is used especially when a small amount of petroleum
is to be spread over a large surface. The amounts given above suffice
for 25 s ]uare metres of soil, say 30 square yards. The action of the
petroleum in these conditions lasts ten to fifteen days.

2. Petroharn KmuUinn and Water. — Petroleum is insoluble in water
but it is capable of forming with it milky mixtures termed " emulsions,"
which have the properties of a solution. It is, however, difficult to ob-
tain a perfect emulsion with these two bodies so different in density ;
even the special apparatus like that of Goff' accomplishes the end in view
with difficulty. Aqueous petroleum emulsions are very unstable, and
petroleum aggregates quickly to reform a layer on the surface of the
liquid. Petroleum and water emulsion is not perfect enough to allow
it to be used on the tender parts of plants, and it is now no longer
used except to disinfect trees in winter, to spread petroleum uniformly
over the iields, and to disinfect seed. Lossen designed a simultaneous
double jet of water and petroleum meeting with force in a common
space, and producing a perfect emulsion, but this emulsion likewise
dissociated on the surfaces touched, forming big drops of petroleum,
always injurious.

3. Lime and Petroleum Emulsion. — Galloway recommends an

PETROLEUM-SOAP EMULSIONS.

299

emulsion made with 1 part of thick milk of Hme from fat hme and
5-30 parts of petroleum. This emulsion is more stable than that made
with water, but less so, however, than that made with soap solution.
It was especially intended to be added to arsenical bouillies to increase
their insecticidal value.

.4. Petroleum Emulsion with Salt Water. — This emulsion is more
difficult to make than that made with pure water, owing to the greater
difference between the densities of the two products. It is frequently-
used in Switzerland, owing to its precious properties against the woolly
aphis : 8 lb. of petroleum are emulsified with 2 lb. of a 25 per cent
solution of common salt.

5. Petroleum Emulsion and Soap Solution. — Petroleum gives with
soapy solutions very stable emulsions. All soaps do not lend them-
selves thereto equally well. The soap lohich gives the most perfect
emulsion is made in America from whale oil. These emulsions keep
a very long time whilst those made with other soaps become curdy in
a few days. To increase the stability of emulsions made from ordinary
soaps, alcohol or carbonate of soda is added. Concentrated stable
emulsions are prepared with the appearance of a cream which are
suitably diluted at the moment of use. A good preparation should be
capable of being diluted to a certain extent without drops of petroleum
forming on the surface of the liquid.

Example.- — 2^^ lb. of soap are cut into thin slices and dissolved in
1 gallon of boiling v?ater. After drawing the fire there is added slowly
with constant stirring 10 gallons of petroleum at 18°-20'' C. ; petroleum
only emulsifies with difficulty below this temperature. To obtain a
perfect emulsion it is necessary on the large scale to stir with a
mechanical agitator, on the small scale with an ordinary spraying
machine drawing in the mixtiu-e and expelling it repeatedly. The
emulsion is more perfect if another gallon of boiling water be added
and the whole mixed once more. Eain water or distilled water should
be used, or the hard water available corrected by carbonate of soda.
Very different mixtures have been recommended ; the following are the
principal ones : —

TABLE LIX. — Showing the Ingredie?its of Several Petroleum Ermilnions.

Water.

Petroleum.

Soap.

10 gallons
10 „

10
10
10

25 gallons

10

10

20

6-7 ,,

20

50 gallons soft soap (Cooke)
100 lb. soft soan (Kriiger)

2i „

6 ,, ordinary soap (Hubbard Riley)
(3-7 ,, ,, ,, (Ritzema Bos)

12 ,, ,, ,, (Alvood)

These emulsions are comparatively stable, less so, however, than those
now made with lohale oil and intended to be kept. They are thinned
when about to be used in such a way that the emulsion only contains
2"5-6 per cent of petroleum, quantities which, according to Fleischer

300 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

and Kruger, should never be exceeded if the emulsions are to be used
on the tender parts of plants. Schoyen asserts that they do not
damage the leaves, especially when the composition is unimpeachable.
Generally dilute and homogeneous emulsions are made when about
to be used ; the following are some proportions recommended : —

TABLE LX. — Ingredients of Four Stable Petroletim Emulsions.

Water.

Alcohol.

Petroleum.

Soft Soap.

Carbonate
of Soda.

100

100

100

96

0-5

1
2
1
1

1
3
2
2

1
2

Eathay
Caruso
Delacroix
Fleischer

These four emulsions are very stable and can be kept. They are the
best. Petroleum and soap emulsions have entirely replaced those of
milk and petroleum. They are in current use in America.

6. Emulsion of Petroleum tvith Fish Oil. — There are emulsified
together at 60° C. petroleum 15 lb., fish oil 2| lb., water 15 gallons.

7. Petroleum and Milk E^mdsion. — Curdled milk forms perfect
emulsions with petroleum (Barnard, 1891) : 2^ gallons of turned milk are
diluted with 10 gallons of hot water, then 20 gallons of petroleum are
added with constant stirring. Ten gallons of petroleum and 5 gallons of
curdled milk can also be emulsified together. If it be desired to use fresh
milk a little vinegar must be added. Sorauer prepares the fresh milk
emulsion although it is not made so easily- To obtain a perfect emul-
sion the liquid to emulsify must be drawn in and expelled for three-
quarters of an hour, if the mixture be at 16° C, during fifteen minutes
at 24° C. (Hubbard). This emulsion is diluted with twenty times its
volume of water before use. The stability of this concentrated
emulsion is less than that of a petroleum and soap emulsion. Unless
it be kept in vessels absolutely closed it spoils in eight to fifteen days.
According to Cooke, plants suffer more from this preparation than
from petroleum soap emulsions.

8. PeA.roleum Emulsion containing Insecticides and Metallic
Salts. — By adding to petrolo-saponaceous emulsions either extract
of hellebore, arsenite of copper, or any other poisonous substance, the
effect of the emulsion is strengthened and a more desirable action ob-
tained. An emulsion, for example, is made with petroleum | gallon,
soft soap 7i- lb., hellebore 2^ lb., water 100 gallons. Smith advises
the addition of 2.1 per cent of petroleum to a cupro-arsenical liouillie.
The bouillie is stable, and the petroleum remains longer in fine division
on the leaves than in pulverizing ordinary emulsions. According to
the sensitiveness of the plant or the resistance of the insect submitted
to the action of this bouillie, the dose of petroleum is increased or
diminished. Kruger advises an emulsion made with equal parts of
petroleum, soft soap, and water, to which quassia or tobacco juice is
added. J)iluted before; use with ten to twenty times its volume of

PETEOLEUM-SOAP EMULSIONS, 301

water, this emulsion kills insects and prevents their return much
longe; than a simple emulsion. In South Amenca flowers of sulphur
are incorporated in the emulsions. They have been successfully used
acainst ermoses. Galloway and Marlatt recommend addmg a proper
quantity, 2-6 per cent, of petroleum to bouillie bordelaise These mix-
tures are more stable than simple emulsions, they keep for eight days.
Of all the emulsions described, those made with soap and petroleum

are to be preferred. mi • j- u„,.

Use against Injurious Fungi.-Pototo Sca&.-This disease, chai-
acterized by an enormous development of the periderm, is caused by
a special bacteria. It may be prevented if some hours before p ant-
ing the soil be impregnated with an emulsion of soap 12^ lb. petroleum
4-5 gallons. This amount suffices for 24 square yards (Frank and

^'Tse against Coleoptera and their Larvae.-It is impossible to.
enumerate all the insects overcome by petroleum. The followmg are
some typical examples : — , i p n,r„i^

Melolonthime (cockchafers). -The larvae of the cockchafers-MeZo-
lontha vulgaris, the common cockchafer; Melolontha Hippocastam the
horse-chestnut cockchafer; Melolontha Fullo, teasel cockchafer; Lachno-
sterna arcuata, red cockchafer-are destroyed or at least so inconveni-
enced bv the presence of petroleum in the soil that they soon desert it.
This effect is best obtained by burying to a depth of 30 inches rags
steeped in petroleum. Perkins, Alvood, Schoyen, and Marlatt ob-
tamed satisfactory results by the use of aqueous or soapy emulsions
Thev found that it was not enough to kill the larva, of these msects.
to sprinkle the soil around the plants with 3-5 per cent emulsions, tor
the larvae descend into the untouched deep layers, rom which they
ascend some time afterwards. The results are, on the contrary, ap-
preciable when the moment is chosen when the larvae have regained
the surface layers of the soil to dig deep narrow holes between the
rows of the young pine or spruce plantations or round the vine stocks
in vineyards. A 20 per cent emulsion of petroleum is run into the
holes which are then filled up with earth, and an hour afterwards
sprinkled with water. Used in this way, petroleum destroys a great
portion of the larva, of these lamellicorns, and protects the plan foi
a certain time against fresh attacks. In Norway, young plantations
of conifers are successfully protected by pourmg into the holes pre^
pared before planting an emulsion of 1 part of petroleum with 13-15
pa -ts of watei- In America, Perkins advises spraying meadows with
emulsLrharmless to grasses, to free them from the larvae of the
Lrir]ino'<ter7ia and the Allorhina niticla.

ElaMec. (wire- worms). -The larva, resist the usual msecticides
better than so t-skinned larva.. Comstock and Slingerland found
petiole im emulsions without action on these larvae. Perkins regai^
Ihem as inefficient and Tarzioni-Tozzetti was only partially successful
with an emulsion of petroleum with fish oil.

^'^■:ZL (welvils).-To get quit of the anthonomes of flo^^^^^^^
and i)revent them laying their eggs, very dilute emulsions otpeti oleum
may be used, sprayed on the flowers before flowering, bchilling oh-

302 IXSECTICIDES, FUNGICIDES, AND WEED KILLERS.

served that this practice succeeded in freeing strawberries from the
strawberry anthonome (Anthonomus rubi, Hbst.).

ScolytidcE (scolytides). — Winter treatment of trees by the petroleum
emulsions destroys both Xylophagus insects which live in burrows dug
in the bark of the tree-i, or immediately underneath it. F. H. Chit-
tenden recommends this treatment especially against Scolytwi riigu-
losus, Eatz. (scolytiTS of fruit-trees).

ChrysomelincB (chrysomelines). — These may be destroj^ed by
petroleum emulsions, especially if hellebore or quassia extracts be in-
corporated therewith. Comstock, Slingerland, Smith, and Von Schilling
recommend the use of soapy emulsions as effective against Criocerus
Asparagi and Phcedon armoracuB, L. (chrysomelide of the radish),
(cochlearia). The}^ destroy the larv«.

HalticincB (altisesj. — Petroleum is very useful in destroying them,
and its good effects on a large number of species have been recorded,
viz. : Haltica oleracea, L. ; PJiyllotreta nigripes, F. ; Phyllotreta
sinuata, Steph.; Phyllotreta undulata, Kutsch.; Phyllotreta nemorium,
L., injurious to the cruciferae ; Psylliodes affinis, Payk., injurious to the
potato ; Haltica vittula, Eedt., injurious to cereals ; Haltica rufipes L.,
iujurious to peas and haricots. In the same way as the individual altises
whose sensitiveness to petroleum has been the object of the above
special observations, all altises in general are killed by petroleum.
Care must be taken not to use too concentrated emulsions so as to
safeguard the plant invaded by the ravisher and only use perfectly
homogeneous preparations. This point is much more important, as
the organs sought after by the altises are the most tender part of the
plant, and, consequently, the most sensitive to the action of petroleum.
Eitzema Bos advises to get rid of altises the use of an intimate mix-
ture of 4 litres of petroleum and 16 litres of sand for 100 square
metres of soil. Used on the spot invaded by the earth-lice, it is found
that they immediately quit the plots treated and do not return until
ten to fifteen days later. This method gets quit of altises when the
plant is small and much exposed to complete destruction b}' the altise.
Comstock, Slingerland, and Lampa advise the use of emulsions with
quassia extract for the same purpose. Petroleum and soap emulsions
are perfectly capable of being of service to agriculturists as destructors
of Coleoptera, especially when it is a question of their larvae. In any
case, the smell of petroleum is so objectionable that those not touched
by it desert the plant treated. Smith, Lintner, and Forbes have shown
that the eggs of the insects have such a resistance that a 30 per cent
emulsion of petroleum does not kill them.

Use against Hymenoptera. — LophyruH Phii, Lophyriis riiftis
(the pine saw-Hy). — ^Eitzema Bos advises petroleum emulsions to
destroy the larvae of these lophyi'es. Their larvtc are very sensitive,
especially when young. The treatment does not injure the pines.

Nematics Bihesii (nematode of the gooseberry), (gooseberry saw-fly).
— According to Johnson the young larvae are killed by a 12 per cent
emuls on, the adults by the same emulsion containing 0-6 per cent of
hellebore decoction.

Use ag-ainst Lepidoptera. — Lepidopterous caterpillars are gener-

PETROLEUM-SOAP EMrLSIONS. 303

ally very sensitive to petroleum, and easily destroyed. According to
Bretssher the caterpillars do not resist a 3-6 per cent petroleum
emulsion. According to Schoyen a cupro-arsenical bouillie of 005
per cent of emerald green is superior in its action to milk of lime
emulsions. According to Moor the grubs touched appear for some
time to he dead, but recover after a while.

Pierides. — White cabbage butterfly grubs are not killed except by
a 6 per cent emulsion of petroleum. At that concentration 75 per
cent of the caterpillars are killed. More concentrated emulsions are
injurious to the leaves (Alvood). It is preferable to preserve cabbages
by keeping off the butterflies. For that purpose it sufiices, according
to Prins's experiments, to sprinkle cabbages with a weak emulsion.

Ocneria dispir, Sch. (gipsy moth). — Petroleum emulsion is of great
service. Berlese found that a 5 per cent emulsion kills them outright.
To destroy the eggs, pure petroleum must be used.

NoctuidcB {Noctua). — Petroleum emulsions kill the numerous
caterpillars of Noctuae.

Agrotis Segetum, W. V. (the common dart-moth grey-worm). — Not
only are the caterpillars of the common dart-moth called grey-worms
but also those of many other species of noctua, because they all have
the same nocturnal habits and much resemble each other. These cater-
pillars often hibernate, and make considerable ravages in the spring
by nibbling the young shoots of cultivated plants. The ravages are
often so great that their destruction by petroleum is always necessary
unless there be many toads on the spot, which are always great
destroyers of these caterpillars. According to Decaux' experiments
made in 1892, three toads suffice per acre to defend a crop. Eiley
advises to kill grey-worms on the large scale by an emulsion contain-
ing 0-5 per cent of soap and 1 per cent of petroleum, which is sprayed
on the fields at the rate of about 1000 litres per hectare (88 gallons
per acre). DegruUy advises a mixture of sulphur 6 lb., lime 4 lb.,
petroleum 10 gallons. Burning rags steeped in petroleum drives
them away without destroying them.

Charaeas graminis. — The caterpillar of this butterfly devastates
meadows When it appears in great numbers (Bremen, 1816 and 1817).
Beuter found that they resist a 6 '6 per cent emulsion.

Mamestris Brassicce, L. (the cabbage moth). — The invaded cabbages
must be sprinkled with a 6 per cent petroleum emulsion. A weaker
emulsion may be used as a preventive before the butterflies lay their
eggs on the young cabbage. Petroleum emulsions have likewise been
tried to combat Tortricides.

Conchj/Us ambignella, Hubn. (cochylis of the vine). — Zecchini and
Silva found that its caterpillar, the worm of the vintage, is destroyed
by an emulsion of 2*5 per cent of petroleum and 1 per cent of soap.
The vine leaves are sensitive to greater strengths ; this dose should not
be exceeded.

Amongst the Tineides or Tinea : —

Plutella cruciferartcm, Zell. (diamond-back moth). — Petroleum is
used in the same way as to combat the cabbage noctua. They are
easier killed if the emulsion contains quassia extract (Fleischer).

304 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Hyponomeuta malinella, Zell. (small ermine apple moth). — Schoyen
advises a 10 per cent emulsion against the caterpillars of this tinea.
The results are grand. At that strength the emulsion even kills the
chyrsalides. The action of petroleum can be localized on the nests
by applying with a brush a 12 per cent emulsion in the evening when
all the caterpillars have re-entered the nest.

Use against Hemiptera. — The phytophagus bugs are destroyed
by petroleum emulsions.

Eurijdema ornatum {Pentatoma ornata), Eurydema oleraceum.
(Pentatoma oleracea). — To kill this bug it takes strong (6-10 per cent)
emulsions of petroleum ; generally they injure the plants as much as.
the bugs. To obtain a perfect result Wood advises to operate thus :
Intercalate in the crops affected by these insects the plants preferred by
them, on which they are not long in installing themselves in mass.
On these they are destroyed with strong emulsions, which kills them
at the same time as the bait plants. In this way, between the rows of
potatoes, mustard radishes or other crucifers are planted.

Lygus jyratensis (meadow bug).' — May be destroyed by a 15 per-
cent petroleum emulsion.

Halticus Uheleri (Giard). — Petroleum emulsions destroy it.
(Chittenden).

Oxycarenus hyalinipennis, Costa (cotton bug). — Marshal destroys,
it with petroleum emulsions.

Tingis Piri (tiger beetle of the pear). — These are killed by spray-
ing under the leaves principally an emulsion containing 1 per cent of
soft soap, 1 per cent of petroleum, and 1 per cent of carbonate of soda.
According to Debray, the winter treatment of fruit trees with 12-25-
per cent emulsions destroys these injurious insects in their winter
refuges.

Use against Homoptera. — The Cicadellides, small grasshoppers,
a few millimetres in length, are often injurious to crops. Petroleum
emulsion kills them effectually.

Jassus sexnotatus, Fall, (grain grasshopper). — Sorauer has used
with success a milk emulsion of petroleum consisting of 2 parts of
petroleum and 1 part of milk, diluted with twenty times its weight of
water. Used against the grain grasshopper it is more active than
lysol and Nessler's liquor.

Typhocyha Solani, Kll. (potato grasshopper). — Von Schilling re-
commends the use of soapy emulsions of petroleum to destroy this
grasshopper. It is, however, well to use a strong emulsion, and wash
the plant afterwards by spraying with water, as soon as the petroleum
has acted on the grasshoppers.

Penthivia atra (grasshopper of the vine). — Marlatt found that a
6 per cent emulsion kills this grasshopper. The vine only supporting,
a 2"5 percent emulsion, the treatment should be followed immediately
l)y washing the stocks treated with a spray of pure water. The psyllas.
or leaf lice arc closely related to the aphis ; they also are injurious to
trees. They are killed by petroleum emulsions.

Psylla Pyri, L. (the pear chermes). — The larvaB are very sensitive
to petroleum emulsions and may be destroyed, whilst the adults are;

9

PETROLEUM-SOAP EMULSIONS. 305

more resistant. According to Marlatt and Slingerland, 33 per cent
emulsions do not act on the eggs, besides they resist pure petroleum,
benzene, spirits of turpentine, carbolic acid, and liquid soda. Winter
treatment with 25 per cent emulsions destroys the hibernating adults.
Spring treatment with 2 per cent emulsion, at the time of the hatching
of the larvae, destroys 90 per cent (Slingerland). Fischer recommends
the extract of quassia emulsion.

Psylla mail, Forst (the apple chermes). — Winter treatment is
without effect, for it is not the adults that hibernate but the eggs. It
is better, therefore, to treat the larvae in the springtime, some days
after hatching, to obtain appreciable success. The more frequent
victims of petroleum are the Aphides (Hce), for the insects of that
family are the most delicate. They are easily destroyed by emulsions
when they are not sheltered in a fold of the leaf in galls (Tetraneura)
or in cankers (Schizoneura) inaccessible to sprays. It is well, there-
fore, to proceed with the treatment before the louse has assumed a
great extension, at .the moment when it is discovered. In these con-
ditions the destruction succeeds, and even the Delacroix 1 per cent
emulsion. Nevertheless, Muhlberg Barnard, Fleischer, Koebele, and
Alvood recommend a 3-4 per cent emulsion against the living lice
in the open, as those of the rose. When the lice are protected under
a curled leaf, as in the case of the apple, peach, and gooseberry,
the treatment does not succeed; 6-6 per cent emulsion only killed 25
per cent of the gooseberry aphis. Kruger's emulsion, consisting of
equal parts of soft soap, petroleum, and water, is most used in Germany
and diluted so as to make a 1-6 per cent emulsion ; in France it is
Delacroix's containing 2 per cent of soft soap,'l per cent of petroleum,
and 1 per cent of carbonate of soda. The winter treatment of trees
with concentrated emulsions, containing 25-30 per cent of petroleum,
cannot act except on species which hibernate in the state of apterous
females, for these emulsions are, according to Goff, incapable of killing
the winter eggs.

Schizoneura lanujera, H. (woolly aphis). — The woolly aphis forms
big cankers on the branches on which the colonies vegetate indefinitely.
These lice form hiding-places there, where it is almost impossible to
reach them, and as they are, moreover, covered with a sort of down,
aqueous insecticides have no action on them, for they neither reach
nor penetrate them. The moment must be chosen when the winter
egg is hatched, for at birth the insects have no down, are delicate and
frail. Concentrated emulsions containing as much as 66 per cent
petroleum ^can then be rased on the cankers, preferably after excising
the ligneous portion. Success is absolute, yet Delacroix and Fischer
I'emark that an ordinary 3-5 per cent emulsion, and even with 1 per
cent of petroleum and 1 per cent of carbonate of soda, acts on all the
lice it touches. Failures only occur with too thick colonies that cannot
be penetrated by the insecticide. In Switzerland, petroleum and salt
water emulsions are used with success. According to Stedman
(Missouri Experimental Station), the ravages of the woolly aphis also
affect the underground portion of the apple-tree. He succeeded in
disinfecting the young trees without injuring their health, by uplifting

'20

306 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

them, cleaning their roots, cutting out any nodosities if need be, and
immersing the roots in a petroleum (kerosene) bath consisting of
2-|- lb. of soft soap, 9 gallons of petroleum, and 90 gallons of rain
water.

Coccides. — In spite of the thick shell which protects the coccides,
they may be overcome by petroleum and its emulsions* when they live
in the open. Petroleum is one of the rare substances which really act on
coccides. In the piu-e state its action is radical. It is recommended
in that state when it is a case of a dangerous invasion which must be
stopped by the complete destruction of the parasite. When cochineals
such as Aspidiotus pemiciosus, Comst. (San Jos6 louse), Aspidiotus
ostreaforniis, Curtis (pear-tree oyster scale), an American coccide
the appearance of which was first reported in France in 1892,
Mytilaspis pomorum, Hook (apple-tree mussel scale), Diaspis piricola
(pear cochineal), and others — when these make their first appearance
in an orchard, pure petroleum must be used, taking the precautions
previously described — precautions which are indispensable to pre-
serve the tree in good health and circumscribe the plague. In most
cases emulsions may suffice, and where the dangerous coccides are in
the endemic condition, as in America, regular annual treatment with
dilute emulsions prevents their too great multiplication in orchards
without completely destroying them. It is the same with the coccides
as with the phylloxera. There is an extinction treatment when
this insect makes its first appearance, and a cultural treatment where
it lives in the endemic state and where it suffices to create a modvs
vivendi between the tree and its parasite. Cultural treatment is
effected with dilute solutions, especially if the moment chosen for
treatment be that when the young delicate larvae emerge from the
protective carapace of their mother, where they have been sheltered
during the first days of their larval evolution. At that time they are
as sensitive as the aphides and succumb to 2*5 per cent emulsions
(Fleischer) or 6-6 per cent (Kruger), which no longer injure the tree.
The adult females covered by their carapace are more resistant. In
winter, 25-30 per cent emulsions must be used against Aspidiotus,
12-15 per cent against Lecanium nigrofasciatum (kermes of the peach,
Johnson), 5-10 per cent against kermes of the lemon-tree. It is well
to give several treatments, at eight or fifteen days' interval, as advised
by Belle, and to follow this winter treatment by a spring treatment
with a weak emulsion intended to destroy the active larvae. In this way
the treatment is complete and without injury to the fruit tree. Belle
advises this treatments to destroy Chryso7)ij)halus minor (orange
cochineal), Targioni-Tozzetti to destroy Pulvinaria vitis, L. (vine
cochineal), and Marchal to overcome Gtierinia serratulcB, Fab. (kermes
of the pine, cypress, and acacia). Petroleum and its emulsions applied
judiciously are capable of easily destroying the coccides.

Use ag-ainst Diptera. — Psila liosce, Fabr. (carrot fly) ; AntJto-
myia lirassicce, Bouche (turnip fly). — Schoyen recommends 12 per
■cent emulsions to oveicome these flies which do great damage.

Use against Acari. — Tetraiiychus telariiis (red spider). — Kolbe
advises the use of an emulsion of 1 per cent of petroleum and 1 per

PETROLEUM SPIRIT. 307

cent of soap, Fernald that of an emulsion containing quassia.
Emulsions of 3-4 per cent containing a little suspended sulj^hur are
also recommended.

Phytoptides. — To destroy them action must be taken the moment"
they invade the buds, that is to say, at the moment the acari are
grouped around these. This treatment is especially used in South
America where acari cause frequent ravages.

III. Petroleum Spirit. — Preparation.— Petroleum spirit is
rectified petroleum, collecting by distilling the hvdrocarbides boiling
between 100° and 150' C. (212-31.2° R).

Action on Plants. — Petroleum spirit is regarded as less injurious
to the tender parts of plants than petroleum oil ; applied by spraying
on the plant it evaporates more rapidly and the plant does not re-
main so long in contact with it.

Action on Insects. — Petroleum sjjirit appears less active on
insects than petroleum oil, and it must be used in larger doses than
the latter. Used in the soil, its radius of action is more extended,
which renders it more apt to overcome underground insects.

Use. — Alvood and Slingerland tried to replace petroleum oil
emulsions by petroleum spirit, but they found the latter inferior.
Mohr, on the other hand, reports the good services rendered against
underground parasites by the following emulsion : —

Mix together 2-i- lb. of oleic acid and 24 lb. of ammonia, then add
1 gallon of petroleum and 1 gallon of petroleum spirit. By an intimate
mixture made by a spraying machine a stable emulsion of syrupy
consistence is obtained. For the destruction of underground parasites,
such as nematodes, larvae of melolonthides, noctua wire-worms, mole
crickets, etc., 1 gallon of this emulsion is mixed with 20 gallons of
water. The dilute emulsion contains about 4 per cent of petroleum,
and behaves in the same way as the ordinary emulsions of soap and
petroleum. To obtain complete destruction Mohr says it is not
enough to spread the preparation in the soil ; holes must be pierced
every 20 centimetres (S inches), 30 centimetres (12 inches) in depth,
and into which 20-30 cubic centimetres of emulsion, say up to a fluid
ounce, are poured ; then the holes are plugged.

CeiUhorhynchus sulcicollis, Gyl. (cabbage weevil). — Underground
injections of diluted Mohr's emulsion kill it, also the following :
Otiorliynchus sulcatus (vine weevil) ; Molytes coronatus, L., weevil
injurious to beets, because it perforates their leaves.

Conchylis avibignella (cochylis of the vine). — Del Quercio advises
an emulsion of 1 per cent petroleum and 1 per cent of soft soap.
Caruso got excellent results by a bouillie of 2 per cent petroleum
spirit, 3 per cent soft soap, and 0"5 per cent alcohol. As for petroleum
emulsions, this emulsion must 1)6 made ten times more concentrated,
and diluted at the time of use by hot water. By applying this emul-
sion on the caterpillars, Martini destroyed 94 per cent, whilst Dufour's
pyrethrum bouillie only destroyed 79 per cent, and rubinia (wood tar)
of 5 per cent strength only 73 per cent.

Tingis Piri. — Del Quercio describes the good effects of an
emulsion of petroleum 1 per cent and soft soap 1 per cent.

308 IXSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Lopus sulcatios {grisette de la vigne). — Pratigeon destroys the adult
larvae by emulsions of petroleum spirit, or of carbon disulphide. So
as not to hurt the vine, he begins the treatment at the time when this
insect has already invaded the young grapes ; but it must be attacked
before hatching on the plants on which it feeds most willingly. A
slight shake is given to the stock ; the larvae, which are already clinging
to the vine, fall to the ground forthwith and the emulsion is then pro-
jected on to the soil. To kill the perfect insect, an emulsion diluted to
at least 2 per cent is projected on the fruit.

112. Vaseline. — Action on Plants.— Vaseline is not harmless
to plants as might be imagined. It acts injuriously like petroleum
hydrocarbides. Shearer found that plants do not support with im-
punity larger doses than 10 per cent. Goethe and Marchal found
that vaseline used as an asphyxiating ointment on the cankers pro-
duced by the woolly aphis is injurious to the plant.

Action on Insects. — Like oils and fats in general, vaseline acts
on insects as an asphyxiant ; it would appear at the same time to
exercise a toxic action analogous to that of petroleum on insects and
their larvae ; contact with it or its emulsions diluted even to 10 per cent
is deadly.

Use, — Vaseline has been used to prepare the sulphuretted vaseline
invented by Meunier in 1887, to overcome the phylloxera. Vaseline
rapidly diminishes the evaporation of carbon disulphide in the soil, and
prolongs its action. Vaseline forms emulsions with soapy water of
the same strength as petroleum, and such emulsions are used in the
same condition ; they are especially used in England. Ward advises
an emulsion of vaseline 0-5 per cent, soap 1-25 per cent, against all
garden insects.

Anthomyia Betce (beet fly) ; AntJiomyiaantiqua, Meig. (onion fly) ;
Anthomyia fiircata, Bche. (onion fly) ; Anthomyia ceimrum (onion
fly) ; Psila Bosa, Fabre (carrot fly). — Whitehead destroys these flies
by an emulsion of vaseline 10 per cent, soft soap 0*25 per cent. It is
used as a spray round the plant before the appearance of the fly.

Thrips cerealium (ihrips of cereals). — Shearer destroys these insects
by spraying with emulsions of vaseline 7 per cent, soft soap 8 per cent.

Ajihides. — Plant lice are killed by an emulsion of vaseline 0*75-1 0
per cent and soft soap 0-5-0-75 per cent (Whitehead) ; vaseline
3 '5 per cent and soft soap 7 per cent (Shearer).

Coccides. — To kill cochineals and kermes emulsions of vaseline
10-12 per cent, soft soap 8-10 per cent, must be used.

113. Acetylene,^ C.,!!,. — Preparation. — Coal gas destroyed by
sparking or incom})letely bin^nt yields this unsaturated hydrocarbide.
It is ol)tainod commeicially by decomposing with water acetylenic
carbides, such as calcium carbide.

CaC, + 2H,0 = Ca(OH), + C.,R,.

As the commercial carbide is always impure, there is formed in ad-

" AcetyU^iii; is like coal->,'as explosive when mixed with 11 certain amount of air.
Anyone storing calcium carbide must comply with the Home Ollice regulations
thereanent. — Tii.

ACETYLENE.

309

dition ammonia 0-24-0 4 per cent, sulphuretted hydrogen 0-7-0-9 per
cent, phosphuretted hydrogen 0018-0-032 per cent (Chuard).i

Properties. — Acetylene is a colourless gas with a slight alliaceous
odour ; it burns with a bright flame. One kilogram of calcium carbide
disengages 300 litres of acetylene.

Action on Plants. — Acetylene has no injurious action on plants.
Leoni found that the germinative capacity of peas and grain did not
suffer from its contact. At a certain strength it must, however, act
like coal gas, which is known to be injurious to plants.

Action on Fungi.— Calcium carbide applied with the bellows, like
sulphur, and projected on to the fungi moistened with water, appears
to be injurious to them, but it only kills the fungi touched. Moreover,
the action of acetylene on fungi is still badly understood.

Action on Insects. — Placed in an atmosphere containing 10 per
cent of acetylene insects die in twenty-four hours. Perfect insects and
larvae of the pea weevil. Briidtus [Britchns jnsi, L.), hidden in the peas
die by the acetylene disengaged when they are enclosed with a small
piece of calcium carbide in a closed space.

Use. — Oidiiim Ti(cl-eri,Bevk. (oidium of the vine). — Huchet was the
first to try calcium carbide on the vine to kill oidium. i\fter moisten-
ing the diseased gi'apes with the spraying machine, finely pulverized
calcium carbide was applied by a sulphur bellows. The effect pro-
duced was decisive, and in spite of the great heat, neither the grapes
nor the leaves suffered. Since then calcium carbide was tried, com-
paratively, against sulphur in Champagne in the vineyards of Chandon
de Briailies, with the result that sulphur and calcium carbide cannot
be used indifferently in the different phases of the disease. When a
stock attacked by oidium has been treated wnth sulphur, it may be
taken for granted, if rain does not intervene and if the weather is warm,
that the vine has been protected against the disease for a month at
least. But the very great efficiency of sulphur when the disease is
recent is less when the attack is an old one. Calcium carbide does not
kill tho oidium except when it is in contact with the fungus, and, more-
over, so that it can act the attacked grapes are moistened when the
carbide dust is projected on to them. Under such conditions, the
action of the product is somewhat energetic on strongly attacked grapes.
In similar circumstances the action of sulphur would be less pro-
nounced. The use of calcium carbide would not appear to be in-
dicated except on grapes to overcome an old and intense attack of
oidium, when the sulphurings have not been numerous enough or
when weather conditions have diminished the destructive capacity of
sulphur.

Gaignardia Bidwelli, Y. and E. (black rot of grapes).— In the
beginning of September, G. Bodies dusted with calcium carbide the
tendrils of the still green grapes attacked with black rot. Some days
after this treatment the fungus had disappeared. Held describes the

1 Chuard and Ettli believing that pliosphuretted hydrogen may aid to a great ex-
tent the insecticide action of calcium carbide, prepared calcium phosphide, CagPj,
\vhich is decomposed by water into lime and phosphuretted hydrogen, so as to test it
comparatively against cdcium carbide.

310 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

injurious action of the lime from acetylene factories used in place of
ordinary lime to coat trunks of fruit trees.

Destruction of Insects. — Melolonthides (cockchafers). — Scri-
baux and Chuard recommend acetylene against the enemies of
crops. They propose to incorporate in the soil, preferably deep down,
a sufficient quantity of calcium carbide in small pieces, which by the
moisture of the soil would be decomposed into acetylene. This decom-
position occurs slowly and gradually. An insecticide gas is formed
capable of occupying a considerable volume of the soil treated. Weak
doses in Germany had no effect. Pieces of carbide of about 50 grammes,
say 1| oz., buried 8 inches down every metre is not enough, as 1 kilo-
gram only yields 300 litres of gas (1 lb. yields 30 gallons).

Phylloxera rastatrix (phylloxera of the vine). — Chuard tried the
cultural treatment of the vine against phylloxera by means of calcium
carbide. His trials in the neighbourhood of Annecy show that vines
treated with carbide exhibit a greater vitality and vigour than the
neighbouring untreated stocks, and on examining several stripped stocks
the phylloxera was absent. The process consisted in stripping the
roots and adding 100 grammes, say 3^ oz., of coarsely crushed carbide.
Trials in Germany on the contrary proved that carbide is unable to
overcome the phylloxera. The question is far from decided, and it is
very possible that in carbide we possess an excellent insecticide capable
of freeing crops from underground parasites.

CHAPTER XIX.

CARBON COMPOUNDS (co7(/iw7/crf)— CHLOROFORM— CAEBONIC OXIDE-
METHYL ALCOHOL— ETHYL ALCOHOL— AMYLIC ALCOHOL— GLY-
CERINE (TRI-HYDRIC ALCOHOL)— ETHER— MERCAPTAN— FORMIC
ALDEHYDE— ACETIC ACID— OXALIC ACID.

114. Chloroform, CHCI3. — Preparation. — Heat in a retort bleach-
iug powder 10 lb., slaked lime 3 lb., ordinary alcohol 2 lb., water 6
gallons. The reaction commences at 80° C, and when the heat is lowered
continues. Chloroform distils. The operation is stopped when 0-3
gallons of liquid has been collected. The liquid separates into two
layers, the heaviest of which is chloroform.

Properties. — Chloroform is a colourless, very fluid liquid, with a
sweet, pleasant odour, and a sharp, saccharine taste. It is only
slightly soluble in water, but very soluble in alcohols. Chloroform is
a powerful caustic ; applied on the skin it irritates it to vesication
and produces local anaesthesia ; its anaesthetic action is due to a
muscular paralysis of the heart. An atmosphere containing 4 per
cent of chloroform is irrespirable. It is deadly at 8 per cent.

Action on Plants. — Its action resembles that of ether. Coupin
submitted seeds to the action of chloroform vapours, and found that
the dry seeds did not suffer in an atmosphere saturated with chloro-
form. It is quite otherwise with moist seeds, the protoplasm of which
already shows some action. They are very sensitive to chloroform, and
an atmosphere containing 0'037 per cent (3 "7 gi'ammes) in 10 litres
of air is deadly. Wheeler made different trials to disinfect seed-corn
by the vapours of ammonia, formol, and chloroform. He found grain
stood the action of ammonia for twenty minutes, formol sixty minutes,
and chloroform ten minutes, without losing their germinative capacity.
Chloroform has a very peculiar action on the growth of plants.
Mrs. Latham found that chloroform stimulated the growth up to a
certain concentration and then slackened it. Kegel found on Elodea
that the stimulating action of chloroform is only shown between 04 and
0"7 per cent, but that above or below these strengths growth is retarded.

[Blooming by Chloroform. — Professor Johannsen, of Copen-
hagen, has been chloroforming plants, and with marvellous results.
He discovered that plants treated with anaesthetics were stimulated
into extraordinary growth. His method is this : —

Lilies of the valley, azaleas, lilacs, and other dormant plants are
placed in an air-tight box, to the lid of which is affixed a small vessel
tilled with chloroform. This, being heavier than air, settles down and
mingles with the plants. At the end of forty-eight houi's the specimens
are taken out and grown in the ordinarv manner.

(311) ■

312 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Nothing in the way of forcing or artificial heat is required. Lilacs
bloom within two weeks of being chloroformed, and lilies of the
valley are hardly so long in coming to maturity. — Added by Teans-

LATOR.]

Action of Chloroform Vapour on Spores. — Wheeler compared
the action of formol, chloroform, ammonia, and carbon disulphide on
the spores of Tilletia with the view of discovering a practical pro-
cess for the disinfection of seed-corn by anticryptogamic vapours. He
found that only the vapours of formol entirely, accomplished the end in
view. Seed-corn is placed in a tube and the vapours of anticryptogamic
substances are passed through it by aid of an air current. Wheeler
in that way obtained the following results : —

TABLE LXI. — Showing the Disinfectant Capacity of Anticryptogainic Vapotirs

on Seed-Corn.

Kind of Vapour.

Action.

Diseased

Ears,
Per Cent.

Formol vapour ....

Untreated

Ammonia vapour

Untreated .....

Cai'bon disulphide vapour

Untreated

Chloroform vapour

Untreated .....

lo minutes
60 minutes
21 minutes
10 minutes

0-00
1-3 5
0-19
0-48
0-1.5
0-35
0-25
0-35

Action on Insects. — Chloroform is poisonous to insects, its vapour
kills them.

Use. — -Coupin advises that in the struggle against the insects in-
festing granaries, carbon disulphide be replaced by chloroform which
has the advantage when used on dry grain of not damaging it like
carbon disulphide.

Coccides. — Eeh found chloi-oform vapour acts very energetically
against coccides. Coquillet who tried it against cochineal of the orange-
tree and lemon-tree did not record perfect results.

114a. Carbonic Oxide, CO. ^Preparation. — This gas is formed
on evei'v occasion thai there is incomplete combustion of carbon owing
to an insufficiency of air to form carbonic acid [to which it burns in air].

Properties. — Carbonic oxide is a poisonous gas. In doses of 4-5
per cent in the air it causes the immediate death of animals. This
action is explained by the way it behaves to the haemoglobin of the
blood. By the coml)ination which it forms with the latter it annuls
moi'e oi' less completely the property of the globules to fix oxygen.

Use. — Carbonic oxide is used to kill the chrysalis of the silk-worm
by submitting the cocoons for eight hours to the action of this gas.
Coquillet also ti'ied unsuccf^ssfully to destroy cochineals by the use of
this gus.

Alcohols. — The alcohols enter into the conijiosition of many
insecticides because they are capabU^ of mixing in aJl pi'oportions with

ETHYL ALCOHOL. 318

water, and maintain in solntion therein the insecticides insoluhle in
■water.

115. Methyl Alcohol, CH3OH. — Preparation. — Methyl alcohol
or wood spirit is a product of the dry distillation of wood.

Properties. — Methyl alcohol is a colourless mobile liquid which
boils at 66-5° C. It dissolves most substances soluble in ordinary
alcohol, such as essential oils and resins. Oxidizing agents convert
it first into formol and then into formic acid. [Highly inflammable.]

Use. — As a solvent in place of ordinary alcohol which it can re-
place in all insecticides with an ethylic alcohol basis.

Phylloxera. — Two mixtui'es have been patented in Germany for
the destruction of this louse. The D.E.P. 50772 claims a solution of
turps and quassia in methyl alcohol, and D.RP. 47775 claims a solution
of animal oil, colocynth, etc., in methyl alcohol.

Galeruca luteoia (galeruca of the elm) ; Erymia nitida (diptera
living on the elm). — It is recommended to desti-oy these by a mixture
of water 100 gallons, tobacco juice 1 gallon, soft soap 10 lb., methyl
alcohol 1 gallon, carbonate of soda 2 lb.

116. Ethyl Alcohol, C.,H^OH.— Preparation. — By the action of
yeast on saccharine solutions certain sugars are under such conditions
converted into alcohol and carbonic acid. All that has to be done is
to distil these liquids to obtain alcohol. Purification is effected by
redistillation of the first distillate over lime.

Properties. — Alcohol is a colourless limpid liquid with an intoxi-
cating odour ; it dissolves in water in all proportions. Alcohol is a
precious solvent not only of inorganic compounds like caustic alkalies,
mineral acids, chlorides, and nitrates, but also of numerous organic
compounds, such as essential oils, resins, camphors ; it also dissolves
fatty bodies, but with greater difficulty. Alcohol boils at 78-4° C.

Action of Alcohol on Plants. — Sandsten examined the action
of alcohol on the growth of plants in a nutritive fluid. Alcohol in
solution of 1 in 10,000 to 1 in 20,000 does not affect the growth of
young plants of phaseolus, vicia, and maize. A 2 per cent solution is
injurious, it excites the movements of the protoplasm and causes
death. The vapours of alcohol may become prejudicial to the health
of the plants if the atmosphere contains moi-e than 1 in 10,000 ; greater
amounts stop growth and cause death. Hiltner found that whilst
ordinary alcohol of 95 per cent strength injures seed, absolute alcohol
on dry seeds has no injurious effect. Alcohol would appear, therefore,
to act on seeds like ether and chloroform.

Use against Insects. — Disinfection of Flower Seed. — Hiltner
recommends to wash with absolute alcohol. The seeds should be dry
and thus without protoplasmic activity.

Plant Lice. — Alcohol enters into the composition of many in-
secticides recommended against plant lice, but it is not so active as
amylic alcohol which replaces it with advantage in all these mixtures.

Scliizonevra Lanlgera, Hausm. (woolly aphis). — Lini^re recom-
mends a mixture of alcohol 30 oz., water 20 oz., potash 1 oz., applied
by the brush on the colonies. In Germany this aphis is easily got rid
of by drenching the colonies and the cankers which they produce, and

314 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

which protect them, with methylated spirit, which is then hghted. Eeh
fouud that alcohol does not kill coccides after two hours' action.

117. Amylic Alcohol, CgH^iOH. — Preparation. — Crude ordinary
alcohol always contains a certain proportion of amylic alcohol,
especially if from the fermentation of potatoes. Amylic alcohol results-
from the secondary fermentation due to special ferments.

Properties. — Crude amylic alcohol used in agriculture is a colour-
less fluid with a sweetish smell which boils between 129° C. and 132°
C. It is not perceptibly soluble in water, but it dissolves in ordinary
alcohol.^

Action on Plants. — It is more poisonous to plants than ordinary
alcohol. Mixtures of soft soap and amylic alcohol cannot always b&
used with impunity on plants without killing them (Fleischer). But
this is gi-eatly due to the action of the soft soap on the leaves and the
young shoots of which a solution of 1-32 per cent strength produces
effects followed by death, and of which a solution of 0-66 per cent
injures plant growth considerably.

Action on Insects. — Amylic alcohol alone is less poisonous thart
its mixtures with soft soap. It does not kill the caterpillar of the
cochylis. These mixtures have, however, a very categoric action on
solt-skinned insects, such as plant lice and caterpillars, and are of uni-
versal use ; they have a better action than aqueous insecticides, because-
they soften the insects touched. Used alone on the cankers of apple-
trees produced by the woolly aphis they destroy it. Spraying with a.
mixture of water and 15 per cent amyl alcohol has been used to re-
move from meadows the laying females of the cockchafer.

Use. — The greater part of the insecticides of commerce are mixtures
of amylic alcohol, soft soap, and an insecticide substance silch as
pyrethra powder, tobacco, etc. Only known insecticides need be
quoted: " Nessler's," "Aphidin," " Antivermin," " Amylocarbol " in
Germany ; " Knadolin " in Switzerland ; Fichet's insecticide in France-
recommended and recommendable for the destruction of plant lice and
caterpillars. Their effects on these insects are indisputable. The.
following are the compositions of some of these insecticides : —

TABLE LXII. — Shoiving the Conqjositioti, of Nessler's Insecticides.

Lb. Lb. Lb.

Soft poap 4 30 5

Amyl alcohol ...... 5 32 10

Ordinary alcohol
Tobacco extract
Potassiuna Kulphide
Water (in gallons)

20 — 20

6 — —

10 10 —

Knadolin. — Soft soap 40 lb., amyl alcohol 60 lb., nitrobenzene

1 Translator's Note. — Amylic alcohol is a most unpleasant substance to handle.
A piece of canvas or an old straw hat coated with a varnish in which amyl alcohol
has been used to dissolve the resin used in the manufacture of the varnish should _
drive off all insects from the neighbourhood. The least trace of amyl alcohol in the '
air causes coughing of a most irritating nature, and an insecticide in which amyl!
alcohol has been used can readily be detected by this means. As the boiling-point
of amyl alcohol is some 32° C. higher than that of water, it will readily be seen that
its irritating vapour is persistent if not permanent.

GLYCERINE (TRI-HYDRIC ALCOHOL). 315

2 lb., xanthogenate of soda 1 lb. The following mixtures are also
used as insecticides : —

TABLE LXIII. — Showhig Composition of Mixed Aviyl Alcohol Insecticides:

Lb. Lb.

Green vitriol ....... 1 —

Sulphate of alumina ...... — 4

Amyl alcohol ....... 5 5

Water (in gallons) 10 10

An analogous insecticide is obtained thus : Dissolve 3 lb. of soft
soap in 10 gallons of hot water, and add after cooling with constant
stirring 6 lb. of ordinary alcohol, then 6 lb. of amyl alcohol ; before
making the mixture the insecticides are incorporated in the alcohol if
they are insoluble in w-ater, and in the soapy solution if they are
soluble in the alkaline liquid. These preparations keep perfectly ;
when used they are diluted as circumstances may require. The
different applications of these insecticides are detailed under Soap.

ii8. Glycerine, CH,OHCHOHCH„OH.— Preparation. — Gly-
cerine is present in all natural fats chemically combined with fatty
acids. It is a by-product of soap manufacture.

Use. — Glycerine is only mixed with insecticides and anticrypto-
gamic solutions to increr.se their adherence to the leaves. It has been
recommended chiefly by Mohr.

1 1 8a. Ordinary Ether, C.,Hf, . 0 . C.,H,.— Definition.— Ordinary
ethei', erroneously termed sulphuric ether, is the oxide of ethyl.

Preparation. — To 7 parts of ordinary alcohol there is added,
in the cold, 10 parts of concentrated sulphuric acid ; the mixture is
heated in a flask to 140° C. and 95 per cent alcohol is allowed to drop
therein so as to keep the temperature constant. In these conditions
alcohol is converted almost entirely into ether and water.

QC.HsOH = C,,H, . O . CoH, + H.O.

Properties. — Ordinary ether is a very mobile liquid, volatile, and
of a penetrating odour. It boils at 35-6° C. It dissolves in 10 parts of
water. [Highly explosive.]

Action on Plants. — An atmosphere saturated with ether vapour
does not lower the germinative capacity of dry seeds, but it only
requires a small quantity, 3 "7 cubic centimetres per 10 litres of air
(3-7 cubic inches per 10,000 cubic inches), to kill moist seeds. Ether
favours the assimilation of the plant in an analogous manner to
chloroform, but whilst it takes 0'5-0"7 of the latter to stimulate this
function, ether acts favourably in 5-6 per cent doses. This action
disappears when the ether is lower or higher than the figures indicated
(Latham). There is also a fixed dose to stimulate the respiratory
functions.

Use. — Conchylis ambignella, Hub. (cochylis of the vine) ; Eiidemis
botrana (eudemis or tortrix of the grape). — Audebert used with
success against the caterpillars of these two butterflies the following
liquid : Ordinary ether 10 lb., essence of absynth 1^ lb., ammoniate
of copper 8| lb., pure rosin 15 lb., carbonate of soda 15 lb., water 95

316 IXSECTICIDES, FUNGICIDES, AND WEED KILLEES.

gallons. To prepare this liquid dissolve the rosin and the carbonate of
soda in 6 gallons of water, boil until of a syi-upy consistence, cool,
remove the excess of liquid, redissolve in the necessary amount of
water, add the ether and the essence of absynth, and when the mixture
is homogeneous add the ammoaiate of copper. The preparation
should form a limped green liquid. This preparation is termed
" Bordelaise insecticide". In 1902 more than 30 million stocks were
treated with this insecticide, either by steeping the grapes or by a very-
fine jet. The amount consumed varies from 300-600 litres per
hectare (26-4-o2'8 gallons per acre). This preparation is recommended
for the destruction of parasites in general, for it kills all caterpillars.
Nobbe and Eichter found that ether could replace carbon disulphide
in the disinfection of the soil. They obtained by the disinfection of
the soil by an ether emulsion a yield of l-o per cent higher than that
of the untreated plot, and they attribute this favourable result partly
to the stimulating action of the small amounts of ether retained in the
soil.

up. Mercaptan, C^H=,SH. — Preparation. — By distilling sul-
phovinate of soda on the water-bath in presence of potassium hydro-
■sulphide.

Properties. — Mercaptan is a colourless liquid with a very un-
pleasant alliaceous odour, boiling at 30° C. (86° F.) and slightly soluble
in water.

Use. — Mouillefert and Eommier tried mercaptan to exterminate
the phylloxera ; 10 drops of mercaptan in a 1-litre flask killed the
phylloxera in two days; tried on the large scale, by distributing in six
holes dug round the infested stocks, a mixture of 12-5 cubic centimetres
of mercaptan and 37'5 cubic centimetres of tar, the eftect produced on
the phylloxera was almost nil.

I20. Formic Aldehyde, HCOH (Formol, Formaline).— Pre=
paration. — By the oxidation of methyl alcohol vapours at a high tem-
perature. It is manufactured commercially by the following process,
due to Trillat. Methyl alcohol is heated in a copper jacketed pan.
The vapours disengaged, mixed with air, are oxidized by passage over
fragments of coke heated to a dull red. The products are afterwards
rapidly al)stracted by a vacuum at a more advanced stage of oxidation.
The commercial concentrated product contains 10-12 per cent of
formic aldehyde. In medicine or agriculture this solution is called
formol or formaline. Polymerized formol is also sold under the form
of pastilles, which by heating disengage formol.

Properties. — Formol possesses a strong sharp odour ; its vapour
irritates mucous membranes, the conjunctive in particular. Formol
is soluble in pure water up to 30 per cent, in presence of methyl alcohol
up to 42 per cent. It has extremely remarkable antiseptic properties,
much reseml)ling those of corrosive sul)Hmate. Ijike the latter it acts
on albumen and arrests, by its contact, the movements and growth
of micro-organisms.

Action of Formol on Plants. — Loew>has pointed out its toxic
action on plants, but formol does not appear to have this action in the
doses in which it is used to combat plant diseases. Utilized almost

FORMIC ALDEHYDE.

317

exclusively to disinfect seed for sowing, it is especialh' from this point,
of view that it has been examined. Its vapours have almost the same
action as its dilute solutions. The action of 0-1-0-2 per cent solu-
tions of formic aldehyde (0'25-0'5 of formaline) is hurtful both to-
cereal grains and leguminous seeds, for it retards germination (Kruger,
Arieti, Niger). However, beet seeds sulfer less. F. Bruning has
examined the point, and got the following results with oats : —

TABLE LXIV.

-Showing Effect of Steeping Seed-Oats in Formal Sohitio7is
on Germination.

Duration

of Action

in Minutes.

A.

B.

Germinative
Capacity,
Per Cent.

Germinative
Faculty,
Per Cent.

Germinative
Capacity,
Per Cent.

Germinative
Faculty,
Per Cent.

0

10

30

Untreated

82
77
78

98
99
99

54
79
57
80

99
99
99
98

A, seeds sown undried ; B, seed air-dried for twenty-four hours before-
sowing. These results show that a 0'3 per cent solution of formic alde-
hyde ( = 0'75 per cent of formol) does not act on the germinative faculty
but solely on the germinative capacity ; it therefore only retards germi-
nation without abolishing it. Cranefield has shown to what point the
germinative capacity is diminished by treatment with formol, and has
demonstrated the effect of the concentration of the formol bath (steep)
on the latter.

TABLE LXV. — Shoic'mg Effect of Tiventy Minutes' Steejmig in Formol Solu-
tions of Various Strengths on the Gervwiative Capacity of Seed-Corn.
Water = 94-5 Per Cent.

Formic

Equal to

Germinative

Formic

Equal to

Germinative

Aldehyde,

Formol,

Capacity,

Aldehiide,

Formol,

Capacity,

Per Cent.

Per Cent.

Per Cent.

Per Ce?it.

Per Cent.

Per Cent.

01

0-25

91-0

0-2

0-5

74-0

0-112

0-28

89-5

0-252

0-61

730

0124

0-31

87-5

0-5

1-25

31-0

0-144

0-36

88-0

1-0

2-50

120

0-164

0-41

88-5

—

—

—

Solutions of formol lower the germinative capacity of seeds the more-
formic aldehyde they contain. The following interesting table, giving
the result of two series of experiments, proves that the injurious action
of formol does not depend on the duration of the steep.

318 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

TABLE LXVI. — Shoivi?ig Effect of Dturation of Steep in Formal Solutionis on
Germinative Faculty of Seed-Corn.

Duratioti
of Steep.

20 minutes

1 hour

2 hours

3 ,,
24 ,,

3 ,,
Untreated

Disinfectajit.

Solution of 0'25 per cent formol, 40 per cent

0-25

0-25

0-25

0-26

Pure water

Germinative

Faculty.

A.

B.

85

89

92

87

86-3

89

88

93

82

78

93

90

95

92

If the seed-corn so disinfected be sown on the fields the effect of
the treatment is visible during the first stage of germination, but after
thirty days there is no difference. A 0"l-0"2 per cent solution of formic
aldehyde, say 0-2-0'5 per cent of 40 per cent formol, may be used
with impunity to disinfect seed-corn.

Action of Formol on Fungi. — The surprising properties of
formol, its action on micro-organisms, were recognized and examined
by Trillat. He determined that its bactericidal capacity equalled
that of corrosive sublimate, and that its extremely ditfusible vapours
are endowed with the same antiseptic properties. He believes that
its action results from its property of rendering albuminous matter
insoluble ; formol acting on the protoplasm of the bacteria hardens
it instantly, and they are thus unable to continue their evolution.
Bardet agrees that formol acts in the same manner as on gelatine,
on the envelopes of bacteria and on the spores of fungi and renders
them unfit to discharge vital functions. It has, on the other hand,
been seen that corrosive sublimate acts in a similar manner on al-
buminous bodies. Numerous experiments made on different bacteria
by Trillat, Berlice, Miquel, AroQSon, Schmitt, Stahl, Wortmann,
Fayollat, and others, show that a dose of 1 in 10,000 to 1 in 20,000
of formol generally suffices to sterilize culture media and to reader
bacteria sterile ; it takes at least 1 in 1000 of formol to kill them.
Penicillium fungi and aspergillus algaB behave similarly, according
to the experiments of Trillat. A solution of 1 in 10,000, or the
ambient air containing 1 in 20,000, prevents the development of young
spores. These are the doses of corrosive sublimate recommended by
Hitchcock, Carleton, and Wuthrich as sufficient to prevent the ger-
mination of the spores of difierent parasitic fungi. The action of
formol on the spores of cryptogamic parasites ought, therefore, to be
about the same as that of corrosive sublimate. Although the remark-
able properties of formol were known since 1888, it was only in 1896
that Geuther tried to use this product in agriculture, and after fortunate
results recommended it for disinfecting seed-corn in place of hot water
or blue vitriol. The ex})eriments made with this end in view show

FORMIC ALDEHYDE.

319

other hand, to dismfeet the seed complete y. ,„earohes on

The following are, moreover, the results ot ditterent researoneb

"' MeS;te has compared the action of bh« vitriol, cor^sive suMim-
ate ai,d formol on the spores of TMetia and obtamed no "^fe^ ^d ears W
by immers.on for one minute in a 24 per <=e"Vo .e„t lit on oi

(I) h, i-mersion for thr-ee n^nutes .r^^^^^^^^^ °,

;Sri^Slrs:e&nr ^ar the l^, e^^^^-
on oats and obtained : —

Hour.

Diseased

Ears,
Per Cent.

Hecke made the curious observation that it sufficed to wash the ^pore^.

even in large* doses does not kill the spores if they ^''^ f «■" »'^^,
JaThed with water. The spores ot ^■^'' 'r^w'^roroTLee hourl

^tLd the devdo'pment of spores, an immersion of fit'-n mmu^es m
0 4 per cent ot formol, of one hour in 0-2 per cent, and three hours m
"■' rctir'^FoTmo. on InsecU.-Insectsw.thstand formol better;
than funt"; coccides are not k.lled l>y formol vapour at er t^ iays
action (Iteh). Solutions are without action on plant hce (Klem), on the

""'asi'-C™-£t:lr (potato scab); B,u.ocU.ua Solan.

320 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

(potato pox and rot of the stem of the potato) ; P]iyto])hthora infestans,
De By. (potato disease). ^ — The spores of these fungi adhere to the seed
potatoes and most often propagate the disease. To prevent this, the
soil and the seed jDotatoes are disinfected by formol, and the results
obtained were satisfactory. According to the experiments of Jones,
Orton, Selby, and Arthur, disinfection by formol is as effective as by
corrosive sublimate. The formol solutions recommended vary from
0'33-0'4 per cent of formol, say 0-16-0-13 per cent of formic aldehyde.
Steeping should last two hours. The following is a convenient method
of working according to Rolfs and Woods : Immei'se the uncut tubers
for two hours in a bath consisting of 4 lb. of 40 per cent formol in 100
gallons of water, dry them, convey them to the field in disinfected
sacks and plant them. Tubeuf, Jones, and Morse recommend the dis-
infection of tubers by formol vapour generated by heating formaline
pastilles in a closed space. Delacroix advises against Bacillus solana-
cearimi the disinfection of the soil by a 0-13 per cent solution of formol
in the proportion of 10-12 litres (2-2-2-64 gallons) per square metre and
steeping the tubers for two hours in a solution of the same strength.
Against Bhizoctinia of the asparagus disinfection of the soil with 60
grammes (about 2 oz.) per square metre. Potatoes so treated only
gave 3 per cent of diseased stems, the untreated gave, on the contrary,
40 per cent.

Botrytis cin&rea (grey rot of the vine). — Tubeuf recommends formol
vapour in a closed space against this fungus. It is possible that on the
large scale formol solutions would act energetically against this mould.
If applied on grapes the moment the disease appears, the effect would,
without doubt, ba salutary, for Trillat has shown the energetic action
of formol on the Penicilium mould, a closely allied species.

Microsjjhcera grossularice, Wallr. (gooseberry blight). — Close records
that a formol solution of O'08-O 12 per cent gives as good results as
potassium sulphide. It is necessary to begin the treatment as soon
as the disease appears.

Ficsariuvi Dianthi, Pr. et Del. — Delacroix having found that formol
vapours killed the chlamydosj)ores of this fungus advised the disinfec-
tion of the soil by formol to prevent this disease.

Fusarium nov. sp., Bolley (flax disease). — Bolley obtained very good
results by disinfecting the seed for sowing by immersion in a formol
solution of 0-5 per cent (0-2 per cent formic aldehyde).

Tilletia and Ustilafjo (bunt and smut of gi-ain crops). — The disinfec-
tion of seed-corn by formol was invented by Geuthei'. It is now
recognized as far superior to the other methods. It results from
numerous trials in this direction that 0-25 per cent formol solutions
(0-1 per cent formic aldehyde) are strong enough and that fifteen
minutes' immersion suffice to disinfect the corn-seed completely. By
this treatment crops can be obtained without any diseased ears. It
is essential not to wash the grain after treatment, for as Hecke has
shown washing reimparts all theii- vitality to the s])ores and thus totally
annuls the (jffect of the treatment. The seed is di-ied after immersion
or planted iinmediatcily after sim})le draining and whilst still moist.
Tubeuf and Neger iiave examined the disinfection of corn-seed in a

FOEMIC ALDEHYDE.

321

closed space by formol vapour and obtained the same results as with
solutions, but the grain must remain at least five hours in an atmos-
phere containing formol. It sufi&ces to heat a tablet of formaline on
a spirit lamp, and close in the space. Bedford compared the action
of bouillie bordelaise made from 2 per cent of blue vitriol and 2 per
cent of lime with that of a formaline solution of 0-2-0-3 per cent. The
results showed the superiority of the formaline.

TABLE LXVIIL— S/iowingf the Results of Growing Oats from TJndisinfected
Seed and from Seed Disinfected by 2 Per Gent Bouillie Bordelaise, and
from Seed Disinfected by "0-2 Per Cent and 0-3 Per Cent Sohttions of
Formaline.

Variety of Oats.

Treatment.

Healthy
Ears.

Diseased
Ears.

Mortgage Lifter .
Doncaster Price .
Flying Scotsman
Mortgage Lifter .
Doncaster Price .
Flying Scotsman
Mortgage Lifter .
Doncaster Price .
Flying Scotsman
Mortgage Lifter .
Doncaster Price .
Flying Scotsman

Nil
Bouillie bordelaise, 2 per cent
Formaline, 0-2 per cent

1 M n

1 Formaline, 0-3 per cent

249
365
392
298
322
295
386
265
298
188
255
262
i

29

49

52

8

32

9

0

0

0

0

0

0

TABLE JjXIX.—Shoiving the Results of Groiving Oats from TJndisinfected.
Seed and from Seed Disinfected by 2 Per Cent Bouillie Bordelaise, and
from Seed Disinfected by 0-2 Per Gent and 0-3 Per Cent Solutions of
Formaline.

Variety of Oats.

Doncaster Price

Treatment.

Nil
Bouillie bordelaise, 2 per cent

Formaline, 0-3 per cent

Dtiration

Sound

1
Diseased

of Steep.

Ears.

Ears. \

163

142

5 minutes

236

98 i

10

175

100 /

5

291

0

10

386

0

30 „

325

0

These results were submitted to a regular control in Canada, and
found exact. Bedford considers that an immersion of five minutes in
a formaline solution of 0-3 per cent suffices to guarantee crops com-
pletely against rust diseases. The seed is sown immediately after
steeping. Selby recommends steeping seed-wheat infested with Tilletia
spores first in water, then to remove the floating ones, then draw off
the water and replace by a 0*2 per cent of formaline. Bolley advises,
a mixture of formol and corrosive sublimate as indisputably superior
to all other disinfectants. It would always give good results.

21

322 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Ustilago crameri (smut of millet). — Hecke examined the effect of
different disinfectants on the spores of this smut. Millet being very
sensitive to hot water, the latter cannot be recommended as treatment ;
disinfection by formol in 0*1 per cent solution is therefore of great im-
portance.

TABLE LXX. — Shoiving the Effect of Solutions of Formaline, Corrosive Svb-
Imiate, Oil of Vitriol, Blue Vitriol on the Germinative Capacity of Millet
Seed and the Spores of Ustilago crameri.

"i

Effect on Seed.

Spores Germinated.

Duration

g .

CO
S3

Treatment.

^ *^ ts

-2 "t*

^

e

531

of Action.

§ § §

5rs

Q ^Oh

fe CL,

O

s

3

CO

CD

o

&H

Formaline

0-25

2| hours

81-5

89

Nil

Nil

Some

0-2.5

6 „

74-0

88

,,

Nil

,,

0-5

2i „

72-5

87

,,

,,

0-5

6 ,,

67

84-5

,,

Corrosive sublimate

0-1

.30 minutes

69

88

,,

,,

0-2

30

69

88

,,

Sulphuric acid

0-5

14 hours

79

83

A few

Great
number

Great
number

Blue vitriol .

0-5

14 ,,

75-5

88-5

Nil

Nil

Nil

Untreated

74

89

Great
number

Great
number

Great
number

To show the good effect of formol as a disinfectant, Hecke sub-
mitted a portion of seed millet to various treatments, and only collected
for sowing the very rusty seed which floated. In these conditions he
obtained in the open field the following result : —

TABLE LXXI. — Showing the Effect of Certain Disinfecting Fluids on the
Crop Produced from the Busty Seed-Corn tvliicJi Floats on the Fluid.

Treatment.

Strength,
Per Cent.

Duration
of Steep.

Number of
Diseased Ears.

Diseased Ears,
Per Cent.

Sulphuric acid .
Blue vitriol
Formaline.
Untreated .

0-5
0-5
0-5J

14 hours
5i ',',

898

54

Jl

1100

81-6
4-9
1-0

Hecke after many trials, which need not be discussed, believed in
the efficiency of formol as a disinfectant for seed millet and in its
superiority to the usual disinfectant if the grains are steeped for fifteen
minutes in 0"5 per cent solution of formaline, or for one hour in 0"25
per cent solution of formaline, or for three hours in 0'125 per cent solu-
tion of formaline.

ACETIC ACID.

323

Ustilago Panici miliacei behaves like Ustilarjo cravicri.

Urocystes Cepnla, Frost (onion smut). — Selby made experiments
to overcome this disease, and it was chiefly by formol and lime that
he diminished it by introducing these products in the soil at the time-
when the onion is sown.

TABLE LXXII. — Showing the Ac ion of Formal and Lime and Mixtures thereof

on Oniin Rust.

Increase of

Trea.ment.

Rust Found.

Onion Crop,
Per Cent.

Quicklime, 33 bushels per acre

Much

82-3

6G

A little

65-2

Formaline solution, 0-375 per cent

Very little

113

0-75

Infinitesimal

119

Quicklime, 1?0 bushels per a'^re .

Nil

120-6

,, 66 bushels per acre )

Nd

132-8

Formaline solution, 0-375 per cent [

The quantity of formaline of 0-375 per cent and of 0-75 per cent
which is used varies from 4675-6540 litres per hectare (411 gallons
per acre to 575'4 gallons per acre). The lime is regularly incorporated
with the soil ; before sowing the onions the formaline is run mechani-
cally on to the. seeds whilst the latter are being sown by the drilling
machine.

Practical Method of Disinfecting Seed=Corn. — An 88-gallon vat
is filled with water and about 1 quarter gallon of 40 per cent formol
added. Two bags containing ^ cwt. of the grain to be disinfected are
then placed therein. A man for fifteen minutes imceasingly turns the
bags in the liquid in such a way that each bag comes in contact with
the formol. The sasks are raised and allowed to drain on two bars laid
over a low vat placed alongside the big vat. The grain is then placed
on the floor of a heated spot and dried at a temperature not above 30°
C. (86° F.), shovelling them until dry. By this method 4 metric tons
of grain may be disinfected in a day with three vats and a floor of 20
square metres (24 square yards). Needless to say, drying may be done
in the open air and in the sun when a proper space is not at disposal.

121. Acetic Acid, CH^COHO. — Preparation. — Acetic acid results
from the oxidation of ethyl alcohol. The acetification of the alcohol
is due to its oxidation, under the influence of an aerobic ferment,
mycoderma aceti, or mother of vinegar, and the oxygen of the air. It
is prepared commercially by letting wine flow slowly into casks filled
with wood shavings "sown" with mycoderma, and traversed from
below upwards by a slight current of air. The alcohol oxidizes rapidly
at 30° C. Acetic acid is also a product of the distillation of wood.

Properties. — Acetic acid is a colourless liquid soluble in water and
alcohol, and boiling at 118° C. Vinegar, which only contains about 10
per cent of acetic acid, is used to preserve fruit. ^

^ Tra?islator's Note. — The author here refers no doubt to the wine vinegar of
France ; the percentage in British mait vinegar is often less than half that given here.

324 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Action on Fungi and their Spores. — Fungi spores are very sensi-
tive to acetic acid (Wuthrich). Dilute acetic acid (0-06 per cent) still
destroys the zoospores of Phytojjhtliora infestans, De By., and acts very
unfavourably on the germination of the conidia of Peronospora viticola,
De Bv. The spores of Ustilago carbo do not germinate after steeping
in acid of 0*06 per cent ; the uredospores of Puccinia cjraminis, although
very sensitive to a solution of 0"06 per cent, are only destroyed by acid
of 0-6 per cent. The latter results agree with those obtained by
Hitchcock and Carleton on Puccinia coronata. These spores do not
germinate after steeping in acid of O'l per cent.

Use. — Goryneum Beyerinckii (gum of trees with stoned fruits,
Nectria ditissima). — Muller advises to overcome the gum of fruit
trees by the following treatment. After having removed the bark,
scraped and planed the wound with the knife, a rag, drenched with
50 per cent acetic acid, is introduced into the wound and covered
with a layer of grafting mastic.

122. Oxalic Acid, COOH . COOH. — Preparation. — By oxidizing
wood sawdust mixed with a concentrated alkaline solution and heated
to 250' C. (482° F.) in wrought-iron cylinders. The mass obtained is
treated with water, and milk of lime added. Oxalate of lime is pre-
cipitated and collected on a filter. The precipitate is decomposed by
dilute sulphuric acid, filtered, and the solution evaporated to crystal-
lizing point.

Properties. — Oxalic acid forms white crystals soluble in 10 parts
of water at 20° C. and in alcohol.

Action on Fungi. — The eifect of oxalic acid on the spores of fungi
has been examined by Wuthrich. This acid behaves very like acetic acid.
The conidia of Pero7ios2)ora viticola, De By., and of Phytophthora infes-
tans, do not germinate in an oxalic acid solution of 0"063 per cent ; the
movements of the zoospores of this latter fungus are arrested, as well
as their germination, by a 0'0063 per cent solution. The spores of
Ustilago carbo behave like the conidia of Peronospora ; however, the
uredospores of Puccinia graniinis are more resistant and are not killed
by a 0*63 per cent solution.

Use. — Nectria ditissima, Tul. (canker of the pear-tree). — Ouvray
advises the use of oxalic acid to overcome the canker of fruit trees.
Clean the wound with a grafting knife, remove everything which is
torn or destroyed, then rub the wound several times with sorrel or
oxalic acid, then cover the wound with mastic or tallow to keep out
the air.

Schizoneura lanigera, Hausm. (woolly aphis). — Oxalic acid appeal's
to be a specific against this aphis, for many scientific observers, such
as Taschenberg, Goethe, and Montillot, boast its good effects. It is as
energetic as Nessler's insecticide. A solution of 1-1'6 per cent pure
or mixed with a little soft soap, is used with the brush on the colonies
of woolly aphis, for the first time in autumn after the ripening of the
fruit, a second time eight to ten days later, and a third time in the
spring.

CHAPTER XX.

CARBON COMPOUNDS (c.onHnm'd)-OlhS AND FATS-SOAPS-HARD SOAP
—SOFT SOAP-WHALE OIL SOAP— FISH OIL SOAP.

123 Natural Fats.— Preparation.— Oils and fats are chemical
compounds of glycerine and fatty acids. They are found m nature
both in plants and in animals. They are extracted either by hot
or cold pressure between plates, or heated millstones, or by an
appropriate solvent— ether, carbon disulphide, chloroform, benzine,
petroleum spirit, etc. • t • . i

Properties.— Oils are insoluble in water ; they oxidize in the air,

resinifying in so doing. , • t^ n m q

Colza oil, extracted from seeds of Brassica campestris—D. = U-yid

at 15° C, solidifies at 6-2° C. .. t^ n oo^

Poppy oil, extracted from seedsof Papacer somniferiwi—D. = U-yJD,

congeals at 19° C. i- ta a mo *■

Olive oil, obtained by hot crushing of ripe olives— D. = U-yiy at

12° C, congeals above 0"" C. • u

Li7iseed oil, extracted from the seeds of Limcm usitatissimum, has a

density of 0-939 at 12^ C. . , u i t^ n qo7

Whale oil, extracted from certain organs of the whale— D. = U-y^^

concretes at 0° C. • j • j-u

Action on Plants.— Vegetable respiration being carried on m the
leaves these organs should remain in contact with the air so that they
may fulfil their physiological functions. The application of oil on the
leaves is therefore injurious to the plant. The pure oils themselves
applied uniformly on the trunk of a tree, have an injurious effect
on the health of the plant. Mouillefert found, in fact, that young
vines are killed if the greater part of their roots are covered with

oil. ., . , •

Action on Insects.— Although the action of oil on insects is
mechanical, they are as efficient as poisonous insecticides. Ihe oil
penetL-ate3 everywhere, and by invading the respiratory organs
asphyxiates the insects. Eggs covered with a layer of oil also die,
because the exchange of gases through the membrane of the egg can
no longer be carried on.

Use.- Oils are used in the pure state or as emulsions with pure
or soapy water. The emulsions are prepared like emulsions of
petroleum with water. ,

Silpka opaca (beet carrion beetle). — Brocchi overcomes the
ravages of this insect in the North by an emulsion of soft soap lb.,
rape oil or poppy oil 15 lb., water 84 lb. Fouquier d'Herouel describes

(8'25)

326 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

its good effects when sprayed on and between the plants to be pro-
tected. One workman treats a hectare (2^ acres) in nine hours.

Atomaria linearis, Steph. — This parasite is overcome in the same
way as the beet silph.

Conchylis ambignella, Hubn. (cochylis of the vine).— Roy advises
to asphyxiate the caterpillars of this butterfly bv dropping one to two
drops of colza oil in each of the silky nests. Muth describes the ex-
cellent results obtained against these caterpillars at the Oppenheim
School of Viticulture by the use of olive, sesame, and colza oils. The
lantern traps in use in Switzerland, for trapping butterflies at night,
are surrounded with a plate which contains a bird-lime consisting
of white pitch 10 ib., Imseed oil 5 lb., olive oil 6 lb., turps 5 lb.
Debray advises to bark the tree with the Sabate glove, and then to
coat them with oil extracted from sulphuretted colza oil cakes [? by
carbon disulphide]. It takes 1 litre of oil for twenty stocks.

Caterpillars and Eggs of Lepidoptera. — Oils and their emulsions
with soapy water are, in general, of indisputable efficiency on caterpillars
and eggs, and are employed in many cases. Saunier recommends an
emulsion prepared in the following way : Dissolve 2 grammes of
carbonate of soda in 1 litre of water, and then add 30 grammes of
linseed oil ; stir until formation of a homogeneous emulsion. The
nests of the caterpillars are sprayed by a hand syringe or by a spraying
machine. The eggs deposited on the surface of the branches are de-
stroyed by coating with the pure oil.

Formica (ants). — Oil emulsions are used to destroy ants : Oil 30
lb., carbonate of soda 5 lb., in 100 gallons of water, or better still,
olive oil alone. It is especially used to destroy the ants which climb
along the branches and trunks of trees (Taschenberg).

Gryllotalpa vulgaris (mole cricket). — Ratzeburg in 1847 advised
to inject oil into the tunnels of the mole cricket and to sprinkle with
water. Before the preparation of the beds, whilst the bed is bare, the
tunnel openings are inspected and a few drops of oil run into each,
then water from a water-can.

Phylloxera vastatrix, Planch, (phylloxera of the vine). — Mouille-
fert has shown that colza, poppy, olive, and nut oils kill the phylloxera
by contact with the greatest of ease. Their use cannot, however, be
adopted on the lai'ge scale, as they kill the plant too readily.

Pollier's process (1872) against phylloxera, which consisted in
coating the stems with an emulsion of whale oil and petroleum, did
not give satisfactory results.

Ajjiiides (green lice). — To kill the eggs of these green lice deposited
in lichens along the trunk or on the end of branches it suffices, accord-
ing to Taschenbei-g, to rub these spots with oil.

Schizoneura lanigera, Hausm. (woolly aphis). — Oils are especially
used to destroy this aphis, as they easily penetrate its wool and
asphyxiate it. The oil should only be applied to small surfaces, nodes,
cankers, holes. Muhlberg advises to coat the cankers with fish oil,
with burning oil, or a mixture of burning oil and petroleum. Muhlers
advises to brush the hotbeds of infection with oil or fat, and to repeat
this treatment every fifteen days. Cirbert advises to rub the infested

SOAPS. ^^'^

puces with a .ag aippea in olive on. OH is --^.ralaTo ^S
which kills by asphyxia ''"J' ^ph'^ ^'^.ch m ght escape a ^^^

According to Kratt, it sumces lo p » .^i^ina lolaster of paris and
woolly aphis with a mastic -f^^ ^^>\3^St medium
linseed oil. Ouvray recommends ^^^^ ^f^^^^^^ ^ ^J naphthalene has
ingthe woolly aphis, burning oil, ^^;;^"^^J^ft^^ leaf the diseased
been incorporated per 10 gallons^ >\^^'off and coated with the
apple-trees are brushed, the ^^^^ f .^^^'^^^^^ Tul fn M^^'^^ °^
naphthalinated oil, taking care not to ^^^^ V^^J^^^^ ts recently
April the tree is again ^^T"'" C^^^lteTl^\^^^^
i/vaded are plugged with ^he -^^^^^^^^^ killed in

Coccules (cochineals) -Cochineals kerme ^ . ^^,.^^

^'^ 'T :Z:iT T^oto ll ared'tht: the too large surfaces.
Xcf itCoftrn^cerryt^cove. may -der t^e^^-^^^^^^^^ 7Z

ous to the plant. This drawback d-^PP^f-', \^^°^^^f, ^U^^^^
oils are used as emulsions with soap ^r petiol^um. ^^^^^^
are got, according to him, ..th an ^^ --^ ^\ ^ ^^^ f^eri^a tie
table oil 15 lb., petroleum ^^ J'^"' ''f^'-i ^^^ ^„u ^n
San Jose louse is overcome with whale oil and fish f- _p^trid

LepuscunMus, L. (rabbit); ^^i^-J-^^^^' ^l,itu the

fish or animal oil protects crops and f^^^\^^^^^^^", ; f^nce consisting
tree may be coated, or the property ^^^^^^^^^^^^ 'n^hes from each

ferret, the martin, and the fox combination of a base with the

,24. Soaps are salts ^^^'^f ^^y the combmat o ^^^^ ^^^

fatty acids present m oils and tats. All ^-§^^^^^^^.^^"^^^^3,^1^. Their
fats yield soap with alkalies and with ^«f "^^^"^f ^f^"'' Solps made
physical properties depend chiefly on ^e base ^sed^^ ^^^^ P ^
From alkaline metallic oxides are f^^^^'^^f^'^^^^^^ 1, ex-lmple,
made from the oxides of other metals, lime ^^ ^T^^^J^P^ ,^,ae from
are, on the contrary, i^^^^^^le m water. Amongs^^ s^^^^^^^^^^
alkalies, hard soda soai. must b^^^^^^^ ,, I,

Preparation.— 1. Haid boaps. ■^'^^'J^ , . •-, ^. y^^-se^Hessoap
soda salts of margaric [palmitic], ^f 5^^'!,^ ° ^^^ ,1'^te^et^^^^^^^ oils with
is the type of this sort. It is made by ^^PO^ f>^"« ^^'fj g^ -^ eli^i.
caustic soda. Glycerine is formed ^^l°^g ^\^^^ ,'^^^^°!^;"eaustic soda
nated in the mother liquor In a arge ^^'^;°^^' .^^^^^.^.^rgradually.
Ive of 10° B. is heated, and the oil to be sapouifaed lun "^^ ^^^_
•^^en the bulk is combined, the ^-Von^^-^^on..^^^^^
of 20 B. Boiling is continued until the whole is homogeneous

328 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

soap is then separated from the water by adding weak salted lye. The
soap which floats is separated from the mother liquor. After com-
plete boiling in fresh salt lye, the preparation of the soap is finished.

2. Soft Soaps. — They consist of the potash salts of the most diverse
fatty acids, for all oils are used in their preparation.

(a) Wliale Oil Soap. — The salt of doeglic acid of whale oil. This
soap is gelatinous, and but slightly soluble in water.

(b) Fish Oil Soajjs. — The oils obtained by boiling decomposing
herrings and other sea fish are much used in America for the prepara-
tion of soap intended to be used against parasitic fungi. Sixty pounds
of caustic potash are boiled in 100 gallons of rain water, and 19 gallons
of cod oil or herring oil. After two hours' boiling, the soap is finished.
The soaps obtained are semi-solid.

(c) Black Soap, Green Soap. — These have a very analogous com-
position, they are the ordinary soft or potassic soaps. These soaps are
gelatinous and soft, containing a great excess of lye and almost all the
glycerine. They are thus very caustic, and act like feeble alkalies.
They are obtained by boiling caustic potash chiefly with linseed, colza,
and hemp-seed oil soap. The solutions are evaporated to a suitable
'Consistency. American arboriculturists prepare a cheap and efficient
•soap by boiling together in 10 gallons of watei*, 12 lb. of lard, and
12 lb. of carbonate of potash. During boiling a milk of lime contain-
ing 5 per cent lime is added. Before using it to coat trees 1 part of
it is diluted with 2 parts of hot water. The bark of the trees
covered with this soap always remains fine and smooth.

Insecticide Preparations. — Soap strengthens the action of certain
Insecticides. It is thus often mixed with the most diverse organic
insecticides to form preparations capable of drenching the insects and
bringing the poisons in contact with them better than aqueous solu-
tions do. Soap emulsions are made with petroleum, benzine,
carbon disulphide, and mixtures with ethyl alcohol, amyl alcohol, and
quassia.

Composition and Preparation of a Few Insecticides. — 1.
Macerate in water for twenty-four hours 14- lb. of quassia ; boil and
mix the extract with 2^ lb. of soft soap in 10 gallons water (Taschen-
berg).

2. Pour 2 gallons of boiling water on 3 lb. of quassia chips,
macerate twenty-four hours, add 5 lb. of soft soap in 2 gallons water.

3. Emulsify 1 lb. of soft soap in 20 gallons water with 1 lb. carbon
disulphide.

4. Emulsify 1 lb. of soft soap in 20 gallons water with 1 lb. petroleum.

5. Emulsify 1 lb. of soft soap in 20 gallons water, 1 lb. carbon
disulphide, and 1 lb. petroleum.

6. Emulsify 5 lb. amyl alcohol, 5 lix of a concentrated alcohol solu-
tion of soap, 10 lb. of carl)on disulphide, and 5 lb. of potioleum, in 100
gallons water.

Emulsions Nos. 3 to G have been used with success at the
Phytopathoiogical Institute of Pisa.

7. Dissolve 3 lb. of soft soaj) in rain water, add 6 lb. of amyl
luJcoIioI, and niikc up Lo 10 gallons with rain water

SOAP SOLUTIONS AND EMULSIONS. 329

8. Dissolve 5 lb. of soft soap in 6| gallons of water, add thereto

2 gallons of ordinary 90 per cent alcohol and 1 gallon of amylic
alcohol.

9. Infuse 3 lb. of tobacco for some time in 5 lb. of amyl alcohol,
and 2 lb. of ordinary alcohol ; add a solution of 4 lb. of soft soap, then
make the whole up to 10 gallons (Muhlberg).

These emulsions cannot be further dwelt upon here, each one will
be described under the heading of the insecticide with which it is
mixed.

Action of Soap on Plants. — Soaps are more injurious to trees the
more caustic alkali and alkaline carbonates they contain. Solutions
of Marseilles soap (hard soap) are less injurious than soft soap ; the
latter becomes injurious, according to plant treated, from 0*66 per cent ;
it is dangerous to flowers from l-32-2'5 per cent, for soapy sprayings
prevent them from producing fruits ; finally, it attacks the skin of stone
fruit, and injures the leaves when tender. Used in winter of great
strength (18-24: per cent) soap renders the trees sterile ; this is not the
case with 6-12 per cent solutions, except for the peach. Mixtures of
soap and alcohol are slightly more injurious than aqueous solutions of
soap, and when concentrated may kill the tree, but it is more especi-
ally mixtures containing tobacco which are dangerous and should be
used with care.

Action on Insects. — Soap in solution acts energetically on soft-
skinned insects and their larvae. A 2 per cent solution acts on cater-
pillars, larvae of wire- worms, etc. Strong solutions of soap also act on
protected insects, such as the cochineals. Marlatt found that, used
on trees in winter, a 24 per cent solution of ordinary white soap killed
more than 97 per cent of the San Jose louse ; an 18 per cent solution
killed more than 95 per cent ; a 12 per cent solution more than 90
per cent ; a 6 per cent solution more than 20 per cent ; and a

3 per cent solution more than 10 per cent. Fish oil soaps are less
energetic. An 18 per cent solution only kills 50-75 per cent ; and a
12 per cent solution only 20 per cent. Whale oil soap solutions of
20-30 per cent kill 90-100 per cent of San Jose louse. In these
mixtures soap whilst an insecticide, generally only acts by bringing the
parasites in better contact with the insecticide and by increasing its
adherence.

Use. — To dissolve the soap, or dilute preparations containing soap,
it is well only to use rain or distilled w^ater, to prevent the lime of
ordinary water from precipitating lime soaps, which encrust the spray-
ing machines.

Cryptogamic Diseases. — SphrerothRca pannosa (rose mildew). —
To overcome this fungus use a 2 per cent solution of soft soap (Vesque).

Mildew of Phlox Drummondii and of Verbenas. — Halsted and
Kelsey overcome this disease by a solution of 31b. of rosin [? soap] in
10 gallons of water. The plants were sprayed twenty-six times from
27 November to 1 April. The action of an emulsion of petroleum
3 gallons, rosin soap 2 lb., water 100 gallons, was much more efficient,
even when diluted three times further.

Insects. — Tomicns dispar, Bostrichus dispar (the apple l^ark

330 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

beetle). — To destroy eggs of this insect deposited on the trunk of fruit
trees and branches a 25 per cent solution of soft soap is used in
Canada.

Oryctes naslcoruis, L. (rhinoceros). — To destroy larvae, water soil
ai'ound stem with 2-3 per cent solution of soft soap (Targioni-Tozzetti).

Elaterides (wire-worms).- — The larvae are killed by 2-3 per cent
solutions of soft soap.

Phoeotribus liminaris (Harris). — Attacks bark of peach-trees in
Canada. To overcome it use a soft soap solution to which the con-
sistency of a thick oil has been given by carbonate of soda in strong-
solution (Fletcher).

Silpha opaca (beet carrion beetle). — To overcome this insect
use a mixture of equal parts of amyl alcohol and soft soap, diluted to
produce 1-2 per cent solutions of soap, which must be sprayed on the
beets.

Crioceris Aspai'agi (the asparagus beetle). — The larvae which live
on the surface of the leaves of the asparagus is killed by Nessler's
insecticide (formula 7) without injuring the plant. Sprayings, if need
be, are repeated in the summer.

Pieris Bapce, L. (small white cabbage butterfly) ; Pieris Brassiccs
(large white cabbage butterfly). — Alvood advises to kill these cater-
pillars injurious to cabbage by spraying the cabbage with 6 per cent
solutions of soft soap.

Gastropacha neustria (the lackey or barred tree lackey moth). —
The caterpillars which shelter at night in a nest of gauze, which they
spin, are dislodged by soap solutions and killed 'afterwards by various
methods.

Conchylis amhignella, Hubn. (cochylis of the vine) ; Eudemis-
hotrana (tortrix of the grape). — Soft soap is an excellent product for
destroying the caterpillar of the cochylis. In 1896 a circular of the
Italian Minister of Agriculture recommends the use against cochylis
of pure soft soap solutions, say mixtures of soft soap and alcohol, or
of soft soap and benzene. A 3 per cent solution suffices (Del
Quercio) ; 2 per cent, according to Passerini. Dufour recommends
a soft soap solution, with which a little tobacco juice has been in-
corporated. In the laboratory this solution, concentrated to 10 per
cent, kills all caterpillars, but it is too strong to be used on the vine.
On the latter a solution stronger than 4-5 per cent of soap must not
be used. According to Petrobelli treatment with soft soap has, how-
ever, a deadly effect on the flowers and the grapes. When the
sprayings are abundant a coating forms on the grape, which ends by
burning the skin ; when there is little liquid a drop accumulates
at the lower part of each fruit, which, in concentrating, attacks the
skin, which tears at that spot. Petrobelli likewise accuses this in-
secticide oF giving a bad taste to the wine.

Hyjxmonieula maUnella, Zell. (small ermine moth of the apple). —
Nessler's insecticide is used to combat the caterpillar of this butterfly
hid in its silky nest.

Gryllotalpa vuUjaris, Latr. (mole cricket). — Corot kills the mole
cricket thus : Before tilling the soil it is well raked to render the

SOAP SOLUTIONS AND EMULSIONS. 331

surface clean and neat ; the earth is then beaten, watering it if need
be. During the night the mole crickets dig new tunnels, which are
seen the next morning. The fresh tunnels are opened with the finger
and tepid soap}' water poured in from a watering-can.

Formica (ants). — Soap is used against ants infesting trees.

Eriocampa adumbrata, Kl. (saw-tiy of the slug- worm or slimy
caterpillar).— Nessler's insecticide (formula 7, p. 328) is an excellent
medium to kill the slimy caterpillar.

Blissus leucopteris, Say.— This bug, injurious to gramineae, is
destroyed by spraying with soap solutions (Quaintance).

Phyllobius oblongus (coleoptera injurious to the pear). — Horfer
recommends abundant spraying with a 1 per cent solution of soap.

Aj)hidce, (plant lice).— To destroy green lice in general Ducloux
recommends two bouillies : (1) Soft soap 5 lb., tar 15 lb., water 2
gallons ; (2) Tobacco extract 2-3 gallons ; soft soap 5-10 lb., methyl
alcohol 1 gallon, carbonate of soda 5 lb., water 100 gallons.

Aphis PajMveris.— Killed by a few sprayings with 5 per cent soap
solution (Noel).

AjMs Rosa, L. (rose aphis).— Green lice, as well as all unprotected
lice, are readily destroyed by pure soap solutions and insecticide mix-
tures with a soap basis. Not being covered with a protective down
like the woolly aphis, and living on the surface of the plant organs,
from which they draw their nourishment, they are far more accessible
to insecticides, and resist them less. The solutions should be diluted
so that neither the soap nor the insecticide injure the foliage. Solu-
tions of 2 per ceat of soap produce the desired effect. Lowe considers
that 1-5 per cent of whale oil soap is better than all the other methods,
if used as a spray, as soon as the lice appear on the young leaves.
As winter treatment to kill the eggs or the adults in their refuge, a
50 per cent solution of soft soap may be used, according to Taschen-
berg. Many mixtures are recommended to replace solutions of pure
soap ; those consisting of quassia and tobacco, and diluted with water
so as to contain 1-5-2 per cent of soap, vide sujjra. Delacroix recom-
mends 1 lb. of carbonate of soda, 2 lb. of soft soap, in 10 gallons of
water.

Schizoneura lanigera, Hausmann (woolly aphis). — Soft soap is used
alone and incorporated with insecticides to kill the woolly aphis be-
cause it penetrates the down of white wax which protects the adult,
and allows the insecticide to act by contact. The U.S.A. Agricultural
Department recommends a 6 per cent solution of soft soap. Muhlberg
records the bad result obtained with a 7 per cent solution of soft soap,
whilst Goethe found a 5 per cent solution very efficient. The season
when the soap solutions are used evidently exercises an important in-
fluence that explains the different results obtained with the same
product, for it is asserted that the young larvae not coated with down,
hatched in November or December, are very sensitive to insecticides,
whilst the adults, owing to the agglomerations which they form, often
escape the action of the most energetic insecticides. It is thus well
to choose the most propitious time for treatment, November and
December. At that time they may be successfully destroyed by

332 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

solutions of 3'3-5 per cent of whale oil, a dose which has no action
on adults. Mixtures of soap and insecticides have a more decided and
radical action, but they also must be applied at the time when the deli-
cate larvge issues from the winter egg. This moment varies with the
different plant lice to such an extent that the time of treatment must
be varied according to the species which it is desired to exterminate.
One of the most energetic insecticides, and also the least injurious to
trees, is that recommended by Nessler, consisting of soft soap, ethyl, and
amyl alcohol : Dissolve 5 lb. of soft soap in 6^ gallons of rain water,
add, after cooling, 2 gallons of ordinary 90 per cent alcohol and 1
gallon of amyl alcohol. A mixture of 3 lb. of soft soap and 6 lb. of
amyl alcohol in 10 gallons of water acts similarly. These insecticides
are applied by the brush, such as they are, in winter during the
hatching of the eggs, on all the nodosities and cankers produced
by this aphis. It is well to prune the tree and to clean the trunk and
the large branches before treatment ; then the whole tree is sprayed
with a solution diluted with an equal part of rain water. Summer
treatment with this insecticide is not sufficient to kill the adult.
Sorauer recommends a mixture of 50 oz. of soft soap, 2 oz. of carbon
disulphide, and 6^ gallons of water. Muhlberg recommends a mixture
with tobacco : 3 lb. of tobacco, 5 lb. of amyl alcohol, 2 lb. of ordinary
alcohol (formula 9, p. 329). If this last preparation infallibly kills the
louse it also injures the buds and the leaves, especially when growing,
whilst mixtures of alcohol and soap of equal strength have not this
drawback.

Coccides (cochineals). — All cochineals are exterminated like the
Aspidiotus perniciosus, Comstock (San Jose louse). Cochineals with a
protective shield resist soap solutions, even concentrated, and insecticide
mixtures containing soap, better than plant lice. As w4th the woolly
aphis, it is best to attack the larvae at the moment they are hatched,
and when they issue from the protective shell of the dead mother.
Pui'e soajD solutions used against the San Jose louse some days before
the fall of the leaf and a little before flowering, in the spring, were
found quite satisfactory by Marlatt and Smith. As already seen the
former obtained with a 24 per cent solution more than 97 per cent of
dead cochineals. Smith, with whale oil soap of 20-30 per cent, up to
100 per cent of killed ; with 20 per cent of white soap, sirengthened by
a little carbonate of potash, 85 per cent. Whale oil soap is the most
energetic of all ; it is now considered as a specific against cochineals.
A tepid solution of soap applied on the young larvae in spring kills them.
(He experimented on the cochineal of the rose laurel.) A hot solution
was used with success by Frank and Kruger. It is necessary to repeat
this last treatment until the cochineals are exterminated. Unfortun-
ately the soap solution to be effective must be applied of such a strength
that it always injures the tree. Winter treatment with 18-30 per
cent of soap always diminishes the blossom ; flowering often does not
occur at all ; the peach is peculiarly sensitive thereto. This drawback
may be avoided, according to Alvood, if the treatment be only applied
in spring, after the formation of the fruit-buds and at the time of iheir
swelling; they are then not so sensitive to the action of soap. Smith

SOAP SOLUTIONS AND EMULSIONS. 333

found that a 5 per cent solution of whale oil soap was quite sufficient to
kill the larvae of all species of cochineals, whilst the young and the
adults still resist. Eitzema Bos believes that cochineals can only be
exterminated by destroying the larvae. With dilute solutions applied
even in summer on the trunks, the drawbacks resulting from the use
of concentrated solutions are obviated. Solutions of soap and amyl
alcohol, those which contain insecticides, are all used for the destruction
of cochineal ; they behave like solutions of pure soap but act in weaker
solutions.

Thrips cercalium (thrips of grain crops). — Quaintance advises
spraying with 0'5 per cent solution of whale oil soap.

Tetranchus telarms (red spider). — Stone, Fernauld, and Waugh
recommend a mixture of sulphur and soapy water to destroy this
acarus.

CHAPTER XXL

CARBON COMPOUNDS {co?iti7med)—imODVGTS OF THE AEOMATIC
SERIES— BENZOL— COAL TAR— WOOD TAR— NAPHTHALENE.

125. Benzene, C,.H,;. —Preparation. — Benzeue or benzol is ex-
tracted from the tar from the distillation of coal. The products of the
distillation are separated by fractional distillation.

Properties. — Benzene is a colourless, mobile liquid with a peculiar
odour, boiling at 80° C. ; its density is 0-880 at 20' C. Benzene is
soluble in alcohol and carbon disulphide ; it is insoluble in water.
It dissolves fats and vaiious resins. Absorbed by man, it produces a
rather dangerous drunkenness. As an injection it produces rapid
anesthesia followed by cramp.

Action on Plants. — Pure benzene has a corrosive action on
plants ; a drop placed on a cabbage leaf makes a hole there in a few
days. Blazek examined the action of benzene vapours on the living
vegetable cell and found an abnormal division of the nucleus, generally
into four without membranous separations. Nemec found the same
degeneration of the cells of Vicia fabia by a 1 per cent solution of
blue vitriol. When cells so modified by the vapour of benzene are
placed in a pure atmosphere, the division disappears and the cell be-
com'js normal. The action of benzene would thus appear to be
unfavourable to the normal evolution of the plant, but this action is
only fleeting and disappears with the cause which produced it. Ben-
zene as a proposed substitute for carbon disulphide has the great
advantage over the latter of being less injurious to the plant and its
roots. The maximum dose borne by a vine in a 4-litre pot is 20 cubic
centimetres emulsified with 20 cubic centimetres water. Trials on
haricots and weeds show that benzene does not kill plants except in
comparatively large doses. Beans stand, as a maximum dose, up to
10 cubic centimetres per 2 litres of earth (10 in 2000) ; weeds only
have the edges of their leaves dried when ^ gramme of benzene is in-
corporated per litre of earth in the soil.

Action on Insects. — Benzene kills insects by contact and by its
vapours. Mouillefert examined its action on phylloxera and found
that dipped in benzene the phylloxera and its eggs were killed in five
minutes.

Use. — It has been proposed to substitute benzene for carbon di-
sulphide ai^'ainst the larvye of the lamellicorns, although the experi-
ments of Mouillefert, in 1876, had shown that it was incapable of
fulfilling this role against the phylloxera. It has, compared with
carbon disulphide, the triple advantage of (1) cheapness ; (2) diffus-
ing more slowly in the soil when it is used with the pal injector ; (3) of
being much less injurious to the roots of plants. In spite of its

(334)

BENZENE. 335

properties it does not replace carbon disulphide, except in isolated
cases, and it can never render the same services as the latter. Its
preponderating advantage over carbon disulphide is that it has a more
prolonged action, especially in warm, dry weather. Benzene is also
used in emulsions against aerial parasites, either pure or mixed with
other insecticides. Debray records the good effect of an emulsion con-
sisting of benzene 2 lb., ordinary alcohol -k lb., soft soap 3 lb., in 10
gallons of water ; and a solution of naphthalene in 8 parts of benzene.

Melolontha vulgaris, L. (cockchafer). — The benzene from gas-
works destroys the white-worm. Mohr advised its use as far back
as 1893. Eitzema Bos records the good results obtained by treating
fields in Holland, Taschenberg those obtained in the neighbourhood
of Trieste, and Croisette-Desnoyers in pine plantations. Injections
of benzene into the soil are made by the pal injector, like those of
carbon disulphide. The nature of the soil, as well as the season,
decides the number of holes and their depth. Thus holes are made of
8-10 inches intervals in light soil and 6-8 inches in heavy soils ; the
larvae of the cockchafer living, according to the season, at different
depths, the depth of the holes with the pal must be varied with the
position occupied in the soil by the white-worm. The depth varies
from 12-28 inches. The precautions to take are described under
carboa disulphide. The amount of benzene to use per hole is 5 cubic
centimetres. Fields of lupines only receive one injection per square
metre. In pine plantations Croisette recommends to make injections
every 70 centimetres (say 28 inches), and two to three injections a year.
The results obtained in young plantations which suffer much from white-
worm are perfect, and the treatment in no way injm'es the trees. Ben-
zene has often given favourable results where carbon disulphide has
failed. These doses sufficient to overcome the lameliicorns never
injure the plant.

Cetonia stictica. — Eitzema Bos and G. Staes advise to destroy it
to inject 5 cubic centimetres into dunghills every 8 inches by the pal
injector. The benzene destroys the larvae.

Elaterides (wire- worms). — Eitzema Bos found that wire- worms,
the larvae of the elaterides, resist benzene injections.

Othiorhynchus sulcatus (vine weevil). — Benzine has been recom-
mended by Mohr in sprayings round the stocks with the view of
destroying the larvae of this weevil. Eitzema Bos regards it as inert
in this instance.

Ceutorhynchus sulcicollus (cabbage weevil). — Mohr advises to com-
bat it with benzene. As soon as the plants have five leaves, holes are
made 8 inches around the plant, 8-12 inches in depth, and 5 cubic
centimetres of benzene run into them and the holes closed up forthwith.
The adult insect may also be exterminated by spraying with a soapy
water emulsion of benzine.

Molytes coronatus (carrot weevil). — To destroy larvae which attack
fleshy part of carrot, Mohr makes round holes round young carrot 4
inches deep, into which he pours 5 c.c. of benzol and fills up at once.

Saperda carcharias, L. {Saperde chagrinee). — To destroy the cater-
pillars in their burrows, chloroform, turps, and benzene are used.
Benzene is preferable. De la Blanch^re operates thus : By means

336 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

of a gouge 1 centimetre (| inch) in diameter the workman widens
and enlarges each hole, which is hidden in the folds of the bark
and under the moss of the lichens, but the presence of which is re-
vealed by detritus resembling moist sawdust. He cuts the edges
neatly, and quickly introduces into the hole a small hook, by means of
which he draws out the detritus which blocks up the entrance to the
burrows. The orifice being cleaned and in perfect communication with
the burrows, the workman introduces, by means of a small needle,
taking care not to press them, two or three plugs of cotton previously
steeped in benzene. He forthwith closes the hole by means of a plug
of rather stiff Eoman cement, which he applies with a small trowel
in such a way as only to penetrate into the hole to a small depth and
to cover the edges with several centimetres of cement. The latter
hardens rapidly and the hole is hermetically closed. The benzene in
volatilizing fills the burrows with its vapours and asphyxiates all the
creatures living therein. When the button which forms round the
wound has repulsed the cement, the odour still suffices to keep off
insects until the wood recloses of its own accord. An inspection every
fortnight after applying this process assures the destruction of all the
generation of the preceding year. The trees so freed do not suffer from
the treatment, heal rapidly, and regain their vigour.

Cossus ligniperda, L. (the goat moth). — The process described for
exterminating the larvae of the Saperdas may be successfully used for
that of the Cossus. To prevent the females from laying their eggs on
the trunk, Truelle advises to coat it with a concentrated solution of
green vitriol, or with a mixture of cow -dung and clay.

Zeuzera Aesculi (the wood leopard moth, horse chestnut Zeuzera) ;
Trochylimn apifonne, L. — The caterpillars of these two butterflies
are combated like the larvae of the Saperdas.

Agrotis segetiim (the common dart moth). — According to Eitzema
Bos, the grey-worm is exterminated by benzene in the same way as
the white-worm and with full success. The caterpillars of an allied
species, Agrotis valUgera, very injurious to pine-trees, are exterminated
in the same way.

Conchylis ambignella, Hubn. (cochylis of the vine) ; Eudeviis
botrana, Schiff. (eudemis or tortrix of the vine). — The Italian Minister
of Agriculture recommends an emulsion of soft soap 3 per cent, alcohol
0*5 per cent, benzene 1-5-2 per cent. Debray obtained good results
with this emulsion.

Lopm sulratus (Grisette de la Vigne, Margotte). — Benzene
emulsions are used as sprays, according to Pratigeon, for the destruction
of the larvae of this bug at the time when they are still on the charlock
and groundsel at the foot of the stems. The adults are thus prevented
from getting on the vines.

Tiptda oleracea (crane-fly, known in England as gaffer longlegs
and in Scotland as daddy longlegs). — The larvtc, injurious as much to
the roots of strawberries as to salads and spinach, may be destroyed
by shallow injections of l)enzene into the soil. It suffices that the
injections be 1 centim(!li-e from the plant, that they do not hurt it.

Tingis Pyri (tiger beetle of the pear-tree). — According to Taschen-

TAE. 337

berg and Caruso an emulsion of 1 per cent benzene and 1 per cent soft
soap is the best way to destroy the tiger beetle and the least injurious
to the pear-tree.

Pulvinaria Vitis, Coccus Vitis (vine scale, vine cochineal), Targioni-
Tozzetti (phylloxera of the vine). — Benzene destroys all the phylloxera
on the roots of the vine in pot, but has proved itself inefficient on the
large scale according to Mouillefert. A stock stripped received -^ litre
of benzene emulsified in 10 litres of water ; the greater part of the phyl-
loxera were destroyed it is true, but the roots at a great depth still bore
numerous living lice. Benzene cannot therefore, it would appear,
replace carbon disulphide.

126. Tar. — Tar is the liquid product which results from the dry
distillation of coal and numerous organic bodies. Its nature varies
with the raw material which gave it birth, but it is always oily, viscous,
of a dark colour, and empyreumatic odour. Tar is insoluble in water.

1. Coal Tar. — Coal tar is a by-product of gas manufacture. It
consists of a mixture of some fifty organic compounds, amongst which
are benzene, toluene, naphthalene, and phenols. It is a black viscous
liquid.

2. Wood Tar. — Wood tar is obtained by the dry distillation of wood.
It is a by-product in the manufacture of pyroligneous acid and wood
charcoal, also in the distillation of pines after the extraction of the
turpentine. When it is desired to obtain tar chiefly, the distillation is
slackened and 18 per cent of tar may be obtained in that way. The
nature of the tar varies with the nature of the wood and the method of
extraction used. Tar obtained by carbonizing w^ood has neither the
same composition nor the same appearance as that obtained by distilla-
tion. The first is black and approaches coal tar ; it contains a large
amount of naphthalene. The second is pale, almost viscous, and con-
tains parafiin. The composition of wood tar is thus more complex
than that of coal tar. It contains benzene, toluene, styrolene, naphtha-
lene, phenols, guaiacols, creosote, and other aromatic compounds. Tar
is used in human therapeutics as an antiparasitic agent.

Action of Tar on Plants. — Tar is a substance comparatively
harmless to the tree. Used such as it is on restricted surfaces of the
bark of a tree — for example, as a circular ring to prevent the access of
insects or to cover wounds — it is without action on the growth and does
not injure the tree.' Tar does not kill the cells which it penetrates, but
it preserves them from decomposition so that neighbouring cells may
grow and develop normally. The cellular layer which is penetrated by
the tar only measures 1-2 millimetres in summer. It is therefore
better to apply tar to wounds in winter. It has been found that tar,
after remaining seventy days on the tree had not been entrained by the
sap, and had not penetrated further thaa at the time of application.
However, Sorauer and Von Tuboeuf remarked that tar must not be
abused on fresh wounds or on young trees, for in their opinion it is
only old wounds and old trees which stand tar with impunity. Eoberb

1 Translator's Note.— This is no doubt true as regards old trees, but tar should
not be applied to young trees with tender bark.

22

338 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

found, however, that far from injuring the trees, the layer of tar, if it be
not too thick, maj^ act as a tonic to the wound and favour cicatiization
and thus enable it to cover itself with fresh bark. Boiteau observed
on stocks treated with tar rather grave disorders at the beginning of
growth : a delay in the latter and chlorotic vine leaves which disappear
later on. Sajo has observed that tar, especially wood tar, is injurious
to dormant eyes. According to Berlese and Fleischer, solutions of tar
in alkali diluted with water are injurious to the leaves above 5 per cent.
Sprayings should never be done during flowering nor before the fruit
has formed.

Action on Insects. — Tar is insecticidal by contact, but its action
is not intense, and it requires strong doses to kill insects. In strong
doses it kills the eggs of butterflies ; in solution in caustic alkalies con-
taining 2-4 per cent of tar it kills insects with soft skins, such as lice
and caterpillars ; from 1-5 per cent it kills Orthoptera, Hyvienoptera,
Lepidoptera, and Diptera (Berlese). The larvae of the saw-flies are
killed by 5 per cent emulsions (Sonnino).

Use. — Bituminous shale was used by the Greeks to keep off insects.
In our days tar is used as it is to destroy the mass of butterfly eggs,
and to form around the trunk an impassable barrier, and a trap to
apterous insects and their larvae, which are obliged either to descend the
tree to continue their metamorphosis in the soil or to ascend the tree
along the trunk after their transformation into a perfect insect. The
bouillies obtained by mixing tar, moi'e especially wood tar, with caustic
alkali, alkaline carbonates, or with soft soaps, are used in spraying in-
sects with a soft skin. A prepai'ation, sold under the name of •' Rubinia,"
•and greatly used, is prepared by boiling 50 parts of wood tar with 50
^arts of caustic soda, 30° B. This preparation is soluble in distilled
•water with a red coloration ; it should be diluted with rain water. Tar
Joouillies are also made containing blue vitriol, naphthalene, and lime.
Howard recommends a bouillie of blue vitriol and tar, obtained by
•^stirring energetically 6^ lb. of coal tar with 5 gallons of boiling water
into which there is poured when the emulsion is complete, and after
removing the blackish froth, a solution of 12 lb. of blue vitriol in 5
gallons of water. Tetard recommends an emulsion with petroleum
and carbolic acid made thus : Heat 6 gallons of tar; remove from the
fire and add while stirring 3 litres of petroleum and 10 litres of
carbolic acid. Balbiani recommends a mixture of coal tar, naphthalene,
and lime prejmred thus : Dissolve 3 lb. of naphthalene in 2 lb. of coal
tar, and pour the mixture into 100 lb. of lime slaked with a little water.
After intimately mixing these substances they are gradually thinned
.by adding 40 gallons of water. Eathay recommends an analogous
bouillie containing 4 lb. of coal tar, 12 lb. of naphthalene, and 24 lb. of
lime in G gallons. " Pitteliene " used in Italy is a mixture of oil and tar.

Use to Destroy Weeds. — One of the most eflicient methods to free
paths and roads from weeds consists in watering them with an emulsion
of equal parts of water and tar. The weeds do not grow again for two
years. But it has the disadvantage of being as dear as hoeing and of
browning foi' some time the spots treated. However, it is expeditious
iind kills (laitb-worms at the same time.

TAR. 339

Use against Fungi. — Sphcerotheca pannosa, Wallr. (mildew of the
rose). — Del Querela and Baroni found that rose mildew was destroyed
by coal-tar bouillies. They advise for this purpose to spray before
flowering with a bouillie consisting of 1^ lb. of carbonate of soda and
^ lb. coal tar in 10 gallons of water. The bouillie injures the colour of
the roses because it is alkaline. Martini prefers a bouillie consisting
of wood tar dissolved in soda lye 14 lb., blue vitriol 1 lb., quicklime
1 lb., in 10 gallons of water.

Ananas (cane-sugar disease). — This fungus is propagated chiefly
by the cuttings. By coating the sections with carbolized tar, Went
overcame this disease, preventively, better than by cupric bouillie.

Nectria ditissima, Tul. (canker of the pear-tree and apple-tree). —
The cankers of fruit trees, whether caused by the woolly aphis or by
the nectria fungus, are overcome and cured when the tree is not too
much infested by completely excising them, and covering the wounds
by a mixture of wood tar and pulverized wood charcoal, or by a mix-
ture of 1 part of coal tar and 4 parts of pulverized slate, or even
by a thin layer of hot tar. The tar prevents contact with the air, kills
the germs of cryptogamic disease, and stimulates the growth of the cells
of the epidermis so that cicatrization is accelerated and large decorti-
cated surfaces become covered with healthy bark in the course of the
year.

Bot of Cuttings. — It has been found that tarring the ends of cuttings
prevents their rotting in the soil. This effect is especially noticeable
when bouillie bordelaise is combined with the tar by dipping the end
to be buried first into the bouillie and then into the tar.

Polyporus igniarius, Fries (false tinder). — To prevent its ravages
care must be taken to cover with a layer of tepid tar all the wounds
produced on trees by lopping, hail, the sun, woolly aphis. If the hoods
of the polyporus show on a branch, this spot must be deeply excised
to desti'oy the greater part of the mycelium, and the whole covered
with tar. Hollow trees may be filled with sawdust impregnated with
wood tar, and the openings plugged with clay or mastic. That pre-
vents the internal decomposition from pursuing its course, for the
fungus must have contact with air for its development.

Slugs. — The ring of coal tar, ^-§ inch wide, is quite sufficient to
prevent snails and slugs from crawling along the trunks of trees and to
avoid their ravages (Pastre).

Use on Insects. — Melnlontha vulgaris, L. (cockchafer). — Eaze-
burg remarked in 1847 that the cockchafer had a great repulsion for
tar. He recommended to protect plants against their attacks to bury
in the hole, dug for planting, a rag steeped in tar. Weny found that
Balbiani's mixture, consisting of tar, naphthalene, and lime, eradicates
the white-worm of the vine, and Landisch points out that it suffices to
insert, at certain intervals, and at a depth of 10 inches, pegs dipped in
tar to protect a crop threatened by the white- worm.

Valgus heinlpterus. — A small sitoma, the larvae of which rapidly
destroy the props and posts of enclosures, by nibbling the underground
part even when tarred. To preserve them, they must be treated thus :
The props and posts are coated in the underground portion with a

340 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

thick layer of white lead ground in oil. Powdered sandstone is dusted
over this layer, and allowed to dry completely. A coat of tar is then
given and the props inserted. The wood is thus unattackable, and is
preserved for a long time.

Bruchus Pisi (pea weevil). — Fleischer recommends to spread the
peas on a sieve and to distribute thereon an emulsion of 1 pint of tar
in 2^ gallons of water, and to stir the peas well.

Otiorhijncliiis pojjuleti (weevil injurious to the vine). — Balbiani's
mixture is recommended by Sajo to eradicate this weevil.

Scolytus rugidosus, Koch. — Scolytus very injurious to apple-trees.
Bauer recommends to cover with tar the parts of the trunk infested.

Anoxia villosa. — The larvae of this insect are injurious to the
Magnolia grandiflora. Camerlings obtains good results by excavating
a pit around these trees 32 inches wide by 10 inches deep, and
watering these pits with 30 litres (6-6 gallons) of an emulsion of 3 per
cent of " Pitteleine". The pits are filled with earth in twenty days.

Galeruca calmariensis (galeruca of the elm). — The most simple
way to destroy these larvae is to seize the moment, at the end of July
or beginning of August, when the adult larvae descend along the trunk
to be converted into a grub in the soil. At this time a ring 4-8 inches
wide is painted round the trunk near the bottom. The larvae which
descend remain glued to this layer of tar. To destroy those which
have let themselves fall, and which are buried in the ground, the soil
round the tree is watered with gas liquor from the gas-works.
Kunckel recommends a bouillie made by making 5 lb. of tar and 1 lb.
of soft soap into a paste, and thinning this preparation with 94 gallons
of water. This bouillie is used to spread on the leaves.

Haltica Oleracea (the garden altise, the altise of cruciferous plants).
— These altises entirely nibble the seedling turnips, cabbages, and rapes,
and other cruciferous seedlings, especially during hot and dry periods
when the fields are despoiled of their crops. At that time a very efficaci-
ous method consists in spreading dry wood sawdust steeped in tar.
The earth fleas are driven off by the smell of the tar ; 2 lb. of tar per
100 lb. of sawdust are used (Bouvier).

Locusta (locusts). — To destroy these on the large scale a 5-10
per cent solution of nabinia is used (Petrobello).

Pieris Brassicce (white cabbage butterfly). — The grubs are killed
by a 2 per cent solution of rubinia (Berlese).

Ocneria dispar, L. (bombyx dispar, gipsy moth, zig-zag) ; Cnetho-
campa processionea (processionary bombyx of the oak). — The eggs of
these bombyces are killed by tar ; a layer of tar is spread on the ag-
glomerations of the eggs. Debray advises to use a mixture of 4 gallons
of tar and 1 gallon of petroleum. Jacobi found the tar more effective
than the petroleum. To kill the caterpillars in their nests Sonnino
sprays with a 5 per cent solution. Pissot recommends to drench the
nests with a mixture of 10 parts of tar and 100 parts of water.
Berlese finds it better to use an emulsion of 2 per cent of " Pitteleine ''.

Bomhy.r pini (the pine-tree lapjxit moth). — Ratzeburg advises, so
as to glue them on their passage along the trunk, to draw a ring on
the bark at the right times, 52 inches from the ground and &\-^^

TAR.

341

inches in diameter. The scales of bark are removed from this spot,
and it is then coated with tar. A little grease is often added, or bn-dhme
made by heating linseed oil. The caterpillars which touch the tar die

in a few days. , t^i i >

Cheimatobia brumata, L. (the winter mothj.— De la Blanchere
finds the best way to overcome this moth is to prevent the female from
climbing along the trunk of the trees to lay its eggs. With this end
in view the trunk is scraped a little above the surface of the soil, and
this ring is coated with tar or with a mixture of equal parts of tar and
fish oil. To protect voung trees sensitive to tar a band of paper or
cardboard is fixed around the trunk and coated with this sticky sub-
stance. The paper must fit well round the trunk. These rings
should be made from the end of September to the end of December,
and renewed from time to time if necessary— every three days if made
with pure tar; at greater intervals if they consist of different sticky
substances. Unfortunately, these last preparations are less harmless
than tar to the health of the tree. Leroux advises to shake the tree
by sharp blows, which causes the females to fall. These to reascend
the tree encounter the obstacle of a fresh layer of tar. The females
hatched prematurely are thus reached. C. de Labonfon advises from
20 October to 20 November to surround the trunks of apple-trees and
pear-trees, about 3 feet from the ground, with a piece of course stuff
held by a hook and steeped in coal tar. The eggs deposited below the
ring by the females, pressed to lay, are destroyed by scraping or by
liming.

Grapholitha Woeberiana (tinea of stone fruit). To overcome this
tinea, the trunk is scraped and a slight layer of tar applied. If the
operation be done in season it will prevent the female from laying its
eggs on the trunk.

Hypoiionmita malinella (small ermine moth of apple-tree).-— io
destroy these caterpillars Taschenberg advises a 5 per cent emulsion.

Conchylis ambignella, Hubn. (cochylis of the vine).— Opinions are
much divided as to the action of "rubinia" on caterpillars of the cochylis.
Fracasso, Legrenz , Farini, and Silva found 4 per cent doses of "ru-
binia " inactive, whilst Berlese, Martini, and Peglion find it energetic at
the same strength. The latter does not injure the vine. Peglion re-
commends to use these solutions l)efore flowering or after the grape is
formed, so as to prevent the injurious action of the product during
flowering. Mixtures of sulphur bouillie bordelaise and " rubinia " are
used in Italy to combat simultaneously cryptogamic diseases and the
cochylis. These preparations destroy the eggs. Martini found that
eggs of the cochylis laid on paper steeped in "rubinia " never hatched
He advises to use the following mixture : " Eubinia " 1^ lb., blue vitriol
1 lb., quicklime 1 lb., in 10 gallons of water. Berlese and Leonardi
recommend spraying the buds as soon as they shoot out with a bouiUie
consisting of 5 lb. of rubinia, 5 lb. of blue vitriol, 5 lb. of lime, m 10
gallons of water. After flowering the sprayings are continued and
rei)eated to the beginning of July with a bouillie of rubmia 1^ lb.,
blue vitriol 1 lb., lime 1 lb., in 10 gallons of water. A dimmut.on of
62-63 per cent of cochylis is obtained in that way. Battaglini recom-

342 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

mends preventive treatnaent either with 1 per cent rubinia or with a
mixture of 2 per cent " rubinia" with sulphur. Spiaying should be
begun on 28 April. The number of eggs diminishes by the first treat-
ment. The eggs disappear after the second, which should take place
on 15 May ; the third treatment is given on 27 June, and the fourth
on 4 July.

Tortrix vitana (p\ ralis of the vine). — G. Basile proposes to coat
the vine after pruning with a mixture of 6 lb. of tar in 10 gallons of
purin. Scalding, however, gives better results.

Hylotoma Bosce (rose saw-fly). — To destroy, spray with 2 per cent
" rubinia," (p. 338) in. fine weather, preferably at noon (Berlese and
Girardi).

Eurydema ornatu7n. — To destroy, water the cabbage leaves with
tar-charged water.

Schizoneiira lanigera, Hausm (woolly aphis). — To destroy this aphis
Del Quercio, after pruning the trees and cleaning the nodosities, coats
the wounds with an emulsion of tar 3 lb., soft soap 5 lb., water 9'6
gallons. In summer an emulsion is used of carbonate of soda 5 lb.,
wood tar 5 lb., water 10 gallons. Muhlberg found that rectified
Eussian tar, and so to speak colourless, is an excellent medium to induce
the cicatrization of wounds formed by the woolly aphis. A tree treated
by an emulsion of soft soap and amyl alcohol, Nessler's formula, and
the wounds of which have been afterwards tarred, may be regarded as
cured. Tiele ranks tar amongst the insecticides who-e action is un-
deniable and decisive.

Green Lice. — Berlese used with success a solution of "Eubinia,"
1-5 per cent, against green lice ; according to Fleischer, it is only with
5 per cent that a deadly action makes itself felt, but at this strength
it is dangerous to the plant.

Phylloxera vastatrix, Planch, (phylloxera of the vine).— Mouille-
fert showed that tar vapours have little insecticide action on the
phylloxera. Used in holes dug round a phylloxera-infected stock,
tar had no action. However, by increasing the dose and getting nearer
the roots so that the tar could act directly and completely drench the
soil, it was found to have an appreciable though incomplete effect.
Tar may be used to destroy the winter egg deposited by this louse on
the aerial parts of the plant. Balbiani recommends for this purpose
his mixture of tar, naphthalene, and lime, used as a coating.

Coccides (cochineal, kermes). — Tar is used sometimes such as it is
to destroy cochineals. A thin layer of tar bouillie is spread with
a brush on all the trunks. Sajo found that it was tar, especially rich
in anthracene, which had a specific action on kermes, chiefly the
Mytilaspis •pomorvm, Bouche. This tar is, however, more injurious to
the apple than ordinaiy coal tar. Del Quercio recommends a soapy
bouillie consisting of tar 10 lb., soft soap 2 lb., water 8-8 gallons. It
is used in winter spraying. Aftei- flowering, and during summer, an
emulsion must be used of soft soap 30 lb., tar 10 lb., petroleum
2 gallons, in 100 gallons of water, and prepared by mixing 20 lb. of soft
soap and 10 lb. of tar on the one hand, and emulsifying, on the other
hand, 2 gallons of petroleum and 10 lb. of soft soap in 97 gallons of
watei', and in mixing the two solutions. This latter treatment is re-

NAPHTHALENE. 343

commended against Mytilaspis fulva, Aspidiotns Limonis, Lecanium,
Hesperidum, Lecanimn Citri, Dactylopius Citri. " Eubinia " is much
used to combat cochineals. Berlese recommends 5 per cent, especially
against Dactylopius Vitis (cochineal of the vine), and Marchal against
kermes of the orange-tree. Girardi recommends the use of a 1 per
cent solution at the moment when the young larvae quit the pro-
tective shell of their mother and circulate round the tree in search of
a place on which to fix themselves. The tar and oil emulsions-
known as " Pitteleine " are recommended by Berlese of 2 per cent
strength against Lecanmm, and by Marchal against kermes of the
orange-tree. Del Quercio recommends for the treatment of winter
fruit trees, an emulsion of tar 1 gallon, carbonate of soda 5 lb., and
water 9 gallons. The carbonate of soda is dissolved in the water and
the tar added afterwards whilst stirring.

A 10 per cent solution of tar kills anthonomes in five minutes.
It must be used for this purpose in October and November. The
females of Mytilaspis poniorum and Diaspis ostreaformis are killed
at the same time as their eggs. It would appear also that the branches-
which have been repeatedly sprayed therewith are no longer sought
after by these cochineals. A 4 per cent emulsion destroys mosses
and lichens. To destroy cochineals, Mottareale indicates on the one
hand, an emulsion consisting of tar oil 10 lb., soap 10 lb., water
100 gallons, and on the other hand, alcoholic solutions consisting of
tar oil 5 lb., alcohol 5 lb., water 99 gallons.

Tetranychus telarins (red spider). — Eathay recommends to bark
the stock in autumn and to coat it w^ith his mixture of tar, naphthalene,
and lime, for in the end of October these acari take refuge under the
bark of the stem. The barks should be burned. Berlese recommends
spraying the plant in full growth with 2 per cent solutions of rubinia.

Rabbits and Mice. — Brecher recommends as an infallible method
to prevent rabbits and mice from attacking the bark of poplars, to
coat the trunk up to 12 inches above the soil with a thin layer of wood
tar. Trantwein agrees.

Birds. — To protect seed-corn against the voracity of birds it
suffices, according to Howard, to moisten it with a bouillie of the
following composition : Blue vitriol 12 lb., tar 6| lb., in 10 gallons of
water. The grain is moistened with this bouillie, then dusted with
slaked hme to dry it. The following bouillie, recommended by Tetard,
is used for the same purpose : Heat 6 gallons of tar, take off" the fire,
and mix with it whilst stirring 3 gallons of petroleum and 10 gallons
of carbolic acid. Crows have a decided antipathy to this odour.
One gallon suffices for 1000 lb. of seed.

127. Naphthalene, Ci^Hj,. — Preparation.— By collecting in the
fractional distillation of coal tar the heavy oils which pass between
180" and 260° C. These are let stand for some time in a cold place :
crystals of naphthalene are deposited which are turbined to separate
the oils containing the phenols and the foreign hydrocarbides. These
naphthalene crystals are passed to the hydraulic press, and afterwards
washed with caustic soda and sulphuric acid, then with hot water.
The rectification is finished by distillation in cast-iron retorts; the

344 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

naphthalene distils between 210" and 220° C. It is collected in conical
wooden vessels slightly moist, in which it solidifies in a few hours.
By reversing the moulds, cakes of pure naphthalene are obtained.
For agricultural purposes crude naphthalene may be used. It is
rarely used alone. It is mixed with such substances as plaster, lime,
wood ashes, or sawdust, is drenched with fused or dissolved naiph-
thalene. A great use is made of a mixture of tar, naphthalene, and
lime, brought out by Balbiani, and named after the inventor, Balbiani's
ointment. It is prepared thus : Slake 120 lb. fat quicklime in lumps
by pouring on to it a small quantity of water from a watering-can. The
heat disengaged by the hydration of the lime is used to melt 20 lb.
of coal tar, and 60 lb. of crude naphthalene, which is run into the
lime whilst it is still steaming. The whole is kneaded by an iron
stirrer. Whilst continuing to stir the mixture a little water is added so
as to sustain the heat of the lime and to keep the mixture pasty.
When the lime is slaked no more water is added, the ointment is
finished when the paste is homogeneous. Solutions of naphthalene
in benzene and alcohol are also used at the rate of 1 part of
naphthalene for 8 parts of solvent (say 1 lb. to a, gallon).

Properties. — Pure naphthalene forms white scales with a strong
odour and a bitter aromatic taste. Insoluble in cold water, very
slightly soluble in boihng water, naphthalene is soluble in alcohol and
benzene.

Action on Plants. — Naphthalene does not appear to injure
plants ; benzene solutions, according to Debray, have no injurious
action on the leaves. Mohr's opinion is, however, that this solution
injures the parenchyma of plants. The germinative capacity of seed
which has been even in prolonged contact with naphthalene is not
diminished.

TABLE LXXIII. — Shoiving Action of Naphthalene on Germi?iative Capacity of

Cotton Seed.

Percentage of Seed Germinated.

Seed Covered
with Cotton.

Seed tcithout
Cotton.

Untreated

Treated with nuphthalene, 8 days
14 ,,
3 „

86
87
91
87

91
91
90

88

Action on Insects. — The experiments of Dufour have shown that
naj)htliiil('ii(!, so to speak, has no action on caterpillars ; however, its
smell is so disagreeable to insects in general that this substance drives
them off and eradicates them at the time of laying theii- eggs. The
vapours of naphthalene stupefy ins(;cts, but they recover in the fresh
air.

Use. — Naphthalene enters into the composition of many anticrypto-

NAPHTHALENE. 345

gamic preparations, such as Crouzel's anticryptogamic, Schloesing's
nicotined precipitated sulphur, to which they impart the special pro-
perties of removing insects whilst overcoming cryptogaraic diseases.

Silpha opaca, L. (beet carrion beetle). — Dust the young plants
with naphthalene to protect them against that insect.

Melolontha vulgaris (cockchafer). — To get rid of the white-worm,
De la Blanchere advises to water the soil with water which has been
kept over naphthalene. Marsaux advises to bury per aci'e with the
plough 2 cwt. of naphthalene mixed with an equal weight of sand.
Finot advises in the culture of strawberries to spread three handfuls
of naphthalene per 10 square metres or to dust the dung with it before
ploughing it in. Audoin recommends the preventive use of naphtha-
lene to drive off the female cockchafers in quest of a light soil in which
to lay their eggs, to sow per acre in April of the cockchafer years 352
lb. of naphthalene per acre, mixed with three times its weight of sand.
This method d'ives off at the same time the females of Vesj^erus
Xatarti in vineyards.

Aqriotes lineatus (striped wire-worm). — When the soil is infested
with the wire- worm larvae of this insect they are got rid off, according
to Targioni-Tozzetti, by naphthalene buried in the soil. The action
of naphthalene does not last long, and the operation must be frequently
renewed.

Helops lanipes, injurious to the same extent as Opatrum sabulosum.
Chapot records excellent results, obtained in driving off these insects,
by the use of 15-20 grammes (say i-f oz.) per stock, mixed with the
soil around the latter.

Colasp)idemumatruvi, 01. (Negril). — Crouzel recommends to spread
by hand, after the last colds of winter and before the lucerne shoots
up, a finely pulverized mixture of 20 parts of naphthalene and
80 parts of plaster or very dry ashes. A fresh application is given
immediat'^4y after the first crop is cut so that only the roots of the
plant and the soil are impregnated. The smell and taste of naphtha-
lene are thus not imparted to the fodder.

Otiorhynchus hirticornis. — Taschenberg reports that coating the
vine with Balbiani's ointment prevented it being visited by this insect.

Atomaria linearis, Steph. — To drive off these destroyers of young
beets Mohr advises to spread on the soil, by means of a bellows, a
mixture of 10-15 per cent naphthalene and 85-90 per cent of lime in
powder passed through a sieve.

Calandria granaria (wheat weevil). — To remove weevils from
wheat seed it suffices to mix it with a little naphthalene.

Crioceris asparagi, L. (asparagus beetle). — A mixture of 15 per cent
naphthalene and 85 per cent of lime in powder kills the larvae and
keeps off laying females.

HalticinecB (altises, earth lice, plant lice). — Thiel and Eeichenbach
have shown that naphthalene does not kill altises, but stupefies them
and drives them away from a crop ; moreover, it is much used for that
purpose. Mohr advises a mixture of 15 parts of naphthalene and
85 parts of lime spread on the fields when the young plants
shoot up. The effect is felt in twelve hours, but it does not last long,

346 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

and the altises return if the treatment be not repeated up to the time
the plant need no longer fear their attack. A mixture of naphthalene,
sand, or dry earth may be spread on seedlings with the same success.
Naphlhalehized sawdust is much used to destroy altises of kitchen
gardens. It is made by dissolving 10 lb. of naphthalene in | gallon of
coal tar, then pouring the solution obtained on 20 lb. of quicklime
previously slaked with water. After thinning the whole down in 15
gallons of water the sawdust is drenched therewith.

Gryllotalpa vulgaris (mole cricket). — To drive it off it suffices to
bury a little naphthalene in the ground as it is being tilled.

Ants. — Sow a mixture of naphthalene and lime where necessary
(Mohr).

Anthomyia antiqua, Meig. (onion fly). — Sawdust (naphthalenized)
or naphthalene buried in the soil when the onions are planted drives
off the fly from these plants and prevents them from laying their eggs.

Tinea granella, L. (grain mite) ; Ephestia Kueliniella (flour mite). — •
The grubs of these tinea cause considerable havoc ; the first in
granaries, and the second in flour mills. They may be removed by
spreading naphthalene in the stores. Seed-corn may be mixed with
naphthalene without prejudice to its germinative capacity, but its
action is less efficient than that of carbon disulphide, and naphthalene
cannot be put in contact with flour to be used as food.

Garpocajjsa pomoneUa (codlin moth).- — Taschenberg recommends
to hook on to the tree rags steeped in naphthalene to prevent the
females from laying their eggs on the young apples.

Conchylis ambignella, Hubn. (cochylis of the vine). — Pradel advises
simultaneous treatment of oidium and cochylis by a mixture of sulphur
9 lb. and naphthalene 1 lb. Dufour has, however, shown that the
vapours and the soapy emulsions of naphthalene did not have much
action on the caterpillars of the cochylis. This treatment, which has,
however, given satisfactory results on the large scale, would only
drive away laying females and cause the grown caterpillars to fall to
the ground. Dr. Paul Cazeneuve found that all the methods of treat-
ment against this insect, pyrethra, soapy emulsions of turps, and petro-
leum, yield inferior results to the sulphur and naphthalene mixture.
Spraying on the grapes is done by a mechanical sulphurator as soon
as flowering commences. Some caterpillars already on the grapes
quit them precipitately after this naphthalenized sulphurating, the
odour of which is repugnant to them. The last treatment is given
between 1 and 10 August to combat the second generation of the
cochylis. The taste of naphthalene in the wine is not to be feared,,
because there is no adherence ; it is washed off by the rain. When
oidium is not to be combated sulphur may be replaced by talc or
plaster. To make an intimate mixture of talc or plaster it must be
passed through a crushing mill (edge runners or flat stones?).

Aphides. — Taschenberg advises to project a mixture of 1 part of
naphthalene with 2 })arLs of ashes or plaster. The moment is chosen
when the leaves are moist with dew, or this treatment is preceded by
spraying with water.

Schizoneura lanigera, Hausm. (woolly aphis). — Solutions of 1 part

NAPHTHALENE. 347

of naphthalene in 8 parts of benzene or alcohol (siy 1 lb. to gallon)
are used in summer to destroy the woolly aphis. The nodosities are
coated with the brush. Better results are got with a solution of 5 lb.
of naphthalene in 10 gallons of burning oil. The asphyxiating action
of this oil makes itself felt at the same time as the insecticidai action
of naphthalene. Guozdenovic destroys the woolly aphis by a mixture
of tobacco extract 15 lb., soft soap 10 lb., naphthalene 4 lb., in 100
gallons of water, to be used by spraying on the colonies.

Pliylloxera rastatrix, Planch, (phylloxera of the vine). — Mouillefert
found that naphthalene had no action on this louse. Trials made on
the large scale by placing naphthalene in proximity to the contamin-
ated roots gave negative results ; however, a German patent advises to
destroy this louse to drench peat with naphthalene carbon disulphide
or tar, and to bury it near the infected stocks. If it is asserted that
naphthalene cannot destroy the perfect insect on the roots, it has been
shown that Balbiani's ointment (mixture of naphthalene tar and lime)
destroys the winter egg, laid on the aerial part of the plant. The
treatment is recommended, both to obtain immunity from the phyllo-
xera in non-infected districts, and as an aid to the underground
treatment of insects. Henneguy, who is a zealous advoc ite of this
process, declares that the coating applied preventively on non-infected
vines suffices to preserve them from phylloxeric invasion. Coating is
done by a painter's brush or by a whitewash brush. The whole wood
of the stem is coated all over the surface of the stock, taking no notice
of buds and cut sections. The work is done preferably after the prun-
ing of the vine during the whole winter. The best time, however, is
the month of February, when the egg's time is up and the louse is
hatched. As there are always some winter eggs which escape this
treatment, the process is not efficient and useful, unless used concur-
rently with treatment imderground by carbon disulphide.

Coccides (cochineals, kermes). — To destroy the cochineal of the
vine, scraping and barking play a great part. They are crowned with
success if this mechanical treatment be followed by coating with Bal-
biani's ointment, the insecticide action of which has been shown by
Couanon. It is especially energetic at the time the larvae are hatched.
Guozdenovic obtained at the Experimental Station of Spalato in Austria
good results against coccides by spraying with an emulsion consisting
of tobacco extract 5 lb., soft soap 2^ lb., finely pulverized naphthalene
^^ lb., in 50 gallons of water.

Phytojytus Piri (gall mite of the pear-tree). — Erinose of the pear-
tree may be overcome after decortication by coating the trunk and the
branches with Balbiani's mixture.

Tetramjchns telarius (red spider). — Viala and Valery Mayet have
recommended the decortication of the stocks followed by coating with
Balbiani's mixture.

CHAPTEE XXII.

CARBON COMPOUNDS (cowiin^erf)— TERPENES-OLEO RESINS— GALI-
POT—TURPENTINE— ROSIN— ROSIN SOAPS— ROSIN EMULSIONS-
METALLIC ROSINATES— COPPER ROSINATE— CAMPHOR.

Terpenes. — Terpenes are met with in many essences and bal-
sams of which they form the liquid part. The different pines and
spruces, the junipers and plants of the family of terebinthaceae, segre-
gate them in the vacuoles of their liber.

128. Turpentine. ^ — Turpentine is the resinous sap ^ {sue resineux)
which flows from incisions Jiiade on trees of the conifer family and
terebinth family. The name of galipot is given to the partially solidified
resin which forms long tangles along the bark. These resinous saps
[oleo resins is the better term] are very complex mixtures. The crude
matter distilled either directly or in a current of steam furnishes about
15 per cent spirits of turpentine ; the residue forms losin of a very
complex nature. [The chemical technology of rosin is fully described
in Mcintosh's " Varnishes," Vol. III., Scott, Greenwood & Son, and the
maker of insecticide emulsions should consult that section of the
book, which deals with rosin and turps, with profit. — (Tr.).]

In the air terebinthene (pinene), which is the carbide of hydrogen
(terpene) of spirits of turpentine, becomes viscous and resinities ; first
the oxygen combines in an unstable way with the terebinthene (pinene),
which under these conditions acquires oxidizing properties similar to
ozone, and thus antiseptic and disinfectant. Turpentine and rosin are
insoluble in water, but they contain saponifiable principles which have
-led to the manufacture of lesinous soaps greatly employed in abori-
culture.

Action on Plants. — The different principles of turpentine are
injurious to plants. Spirits of turpentine (turps) 2-5 fluid oz. per 6-^
gallons bulk of soil is already very poisonous to plants, especially the
vine. The aerial organs touched by spirits of turpentine emulsions
are damaged, and the spraying of the trunk of vines causes burns.
Turps appears more dangerous to the plant than petroleum ; resins are
more poisonous than tar.

Action on Insects. — The products contained in turpentine have
a very pronounced destructive action on insects. Turpentine | ? turps or
oleo resin] spread on tlie agglomeration of eggs of Ocncria dispar
(gipsy moth) acts as efliciently as tar (Eobbes, Sajo).

Use. — Spirits of Trnpentine (turps). — Turps is never used alone

' Turpentine is not the sap or juice of the tree. It is nn oleo-resinous exudation
and bears a somewhat siniihir relation to true sap as sweat docs to the blood.
Spirits of turpcmtine is often i)ut most erroneously (h!si{i;nated as " turpentine," a
term to which it is no more entitled than starch is to beinji; termetl wheat or
potatoes. — Ti!.

(;J48)

ROSIN SOAPS. 349

if it be not to destroy the agglomeration of eggs of certain butterflies
(Ocneria dispar, gipsy moth). It is used in emulsion with water or
soap solution, most often with carbon disulphide, milk, or tar.

Conchylis ambignella, Hubn. (cochylis of the vine). — In Dufour's
insecticide turps replaces pyrethra powder, which is difficult to procure
fresh. Dufour dissolves 30 lb. of soft soap in hot water, adds cold
water to make 100 gallons, and incorporates 2 gallons of turps in this
soap solution, then emulsifies the whole with a spraying machine. It
is necessary to use 13-2-35-2 gallons per acre.

Schizoneura lanujera, Hausm. (woolly aphis). — A mixture contain-
ing turpentine [oleo resin] has been elaborated by Goldi, and is in
common use against the w^oolly aphis. This mixture has the following
composition : Fresh milk 60 per cent, turpentine [oleo resin] dissolved
in turps 20 per cent, carbon disulphide 20 per cent. In a stoppered
bottle this mixture keeps a long time. The aerial colonies are coated
with a brush. To disinfect roots, the following mixture must be used :
Milk 60 per cent, turpentine 30 per cent, carbon disulphide 10 per cent.

Graft iitfi Wax. — To cover the wounds after destroying the insect
gi'afting wax is recommended (rule in force in the Canton of Argovy in
Switzerland), consisting of Venice turpentine 65 percent, turps 20 per
cent, ochre 20 per cent, or 75 per cent of turps and 25 per cent of tar.

Phylloxera rastatrix, PI. (phylloxera of the vine). — Mouillefert
examined the action of turps on the phylloxera, and found that it was
very pronounced. If it perfectly destroyed the phylloxera, on vine
roots planted in pots, it was not the same on the large scale. By
treating the stocks with 400 cubic centimetres of turps emulsified with,
water, and sprinkling afterwards with w^ater, and bringing the earth
back around the stripped stocks, this product has proved powerless tO'
destroy the insect in the lower reaches of the soil. The coating of the
trunk and the roots of the phylloxera-infected vine w'ith 50-100
cubic centimetres of turps (Sans process, 1872) has given no favour-
able result.

Cochineal. — Hoffmann recommends to render soapy emulsions
more energetic against cochineals to add carbon disulphide or turpen-
tine (? turps). An emulsion of 2 per cent soft soap and 2-3 per cent of
turpentine (? turps) gives excellent results.

Moles. — To drive away moles, it suffices to pour water in their
burrows, and to lower a cup containing a mixture of petroleum and
turpentine.

129. Pine and Spruce Resin [? Bosin]. — These are used in : (1)
Soap emulsions ; (2) the preparation of coatings and bird-limes ; (3) in
cupric bouillies to render them more adherent. The resins [? rosins]
are used as such or saponified.

(1) Saponified Resins [rosin soaps]. — Preparation. — Several
methods are used in America ^ : —

1 These formulae are given in tiie original French edition of this treatise in
metric weights and measures. But the author like every other author who quotes
American formulae seems to forget that an American gallon is only five-sixths of an
Imperial gallon. In America the pound is not the tenth part of a gallon but three-
twenty-tilths. Had the author made allowance for the American gallon it would
have been impossible for him to have got the French quantities in such round
numbers to the litre.

350 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

1. Dissolve 1 lb. of 98 per cent caustic potash in 4 gallons of water;
add thereto 9 lb. of rosin, heat until complete solution is effected and
make up to 10 gallons by adding the necessary water. The brown
liquid so obtained is translucid (Koebele).

2. Boil together for one hour 7 lb. of 70 per cent caustic potash,
25 lb. of rosin, and 3 lb. of fish oil, with 10 gallons of water. As
soon as the mass rises and becomes frothy, stop the boiling and make
up with water to 100 gallons (Coquillet). This bouillie is the classic
rosin bouillie of Amer.ca. The followmg formulae are now in use.
Formula A : caustic potash, 70 per cent, 6 lb., rosin -5 lb., fish oil
3 lb., water 10 gallons. Formula B : caustic potash, 70 per cent, 10 lb.,
rosin 35 lb., fish oil, 5 lb., water 10 gallons. Formula A is used in
summer, thinned down according to the sensitiveness of the tree, with
seven to nine times its weight of water. Formula B is only used in
winter when the sap is dormant.

3. 164^ lb. rosin, 2^ lb. caustic potash, 98 per cent, and 2^ lb. of fish
oil are heated together and then dissolved in 10 gallons of water.

4. 16 lb. rosin, 4 lb. 98 per cent caustic potash, 2^ lb. of fish oil are
melted together, and boiled in 10 gallons of water, cooled, and 4 gallons
of water added. Before use 1 part is diluted with 9 parts of water
(Swingle).

5. Dissolve 8-10 lb. of commercial rosin soap in 10 gallons of
water.

Action on Plants. — Soap solutions of 0"8-l-0 per cent strength
do not injure the leaves. A bouillie six times stronger than Formula A
used warm in December and January, resulted in the total absence of
flowers in the spring (Marlatt).

Action on Insects. — Eosin emulsion acts very energetically on
insects owing to its causticity ; it acts by contact and it forms besides
on the insect which it has drenched an impermeable coating which
causes asphyxia.

Use. — Rosin bouillies are much used in America against cater-
pillars, and especially against cochineals ; they replace petroleum
emulsions. They give very good results in countries wheie the pro-
longed absence of rain assures the efficiency of the treatment for a long
period, and where the multiplication of the cochineal, owing to the
heat, goes on almost without interruption the whole year round.
Petroleum emulsions are preferable in districts where rain is frequent.
When a resinous bouillie is used on a tree invaded by cochineal the
bark of the tree must, as far as possible, be entirely drenched. In
temperate countries two or three applications must be made at eight
days' interval, and preferably at the time when the mobile larvae
circulate in quest of a spot on which to fix themselves. The treat-
ments do good on deciduous trees. When the tree is much attacked
it must be severely pruned before spraying. To give all its efficiency
to the winter treatment, a dose six times stronger must be used than
in summer, when, on the contrary, the bouillie made from No. 2
formula is thinned down with nine times its volume of water.

J-}y this jH'Ocess, and with the emulsion from formula No. 4, Swingle
and Webber destroy the following caterpillars and lice : Ceroplastes

BIBD-LIMES. 351

fluoridensis, Dactylopius Citri, Aphis gossypii, Glover ; Lecanivm Olece,
leery a purchasi, Aleyrodes Citri. Gossard used with great success an
emulsion of ground rosin 16 lb., caustic soda, 98 per cent, 3-4 lb., fish
oil 2-^ gallons, water 100 gallons, applied in winter when the cochineals
are in the larva state. Marlatt recommends to destroy Aspidiohis
Aurantii, Mask, Aspidiotns citrinus, Coq., the summer bouillie
formula No. 2 A. A bouillie four times stronger kills 85 per cent of
Aspidiotns perniciosus, Comst. (San Jose louse), Phorodon Humuli
(hop aphis). It does not stand spraying with a solution of rosin soap,
formula 5.

Phylloxera vastatrix, Planch, (phylloxera of the vine). — Koebele's
trials were a failure. Emulsions do not penetrate the soil sufficiently
and do not reach all the phylloxeras. Only the insects touched die.

Aspidiotus uvce, Comst., on vine. — Galloway's bouillie No. 3 is
recommended for its destruction.

Teiranychus telarius (red spider). — Bouillie No. 3, diluted with
3-4 parts of water, is recommended to destroy it.

(2) Compositions and Bird-limes (Enduits etglus). — Formula for
preparing coating compositions: 1. 200 oz. spruce resin {resine de
sapin, ? Burgundy pitch) are heated over a gentle fire until fused, then
5 oz. of linseed oil and 10 oz. of honey added ; when the mixture is
homogeneous it is removed from the lire, cooled, and 28 oz. (wt.) of
90 per cent alcohol added. This coating should be kept out of con-
tact with air ; it is used cold (Lucas).

2. 500 oz. of spruce resin are fused and dissolved in 75 oz. (wt.)
of 90 per cent alcohol ; 4 oz. of gum-arabic dissolved in very little water
are added, and 20 oz. of carbonate of soda.

3. Melt together equal parts of rosin, wax, and turpentine. This
composition is applied hot (Sorauer).

iJi/rZ-/ jmc.5 are made as follows : 1. Heat together and i^educe to
two-thii'ds of the original volume 2^ lb. of colza oil and ^ lb. lard, then
add whilst stirring ^ lb. of turpentine and ^ lb. of rosin. The con-
sistency should be syrupy ; if it be too fluid the heating is to be con-
tinued, if it be too thick more oil is added. This bird-lime remains
sticky for three months.

2. Heat together 5 oz. of rosin, 4 oz. of stearine, and 4 oz. of lard.

3. Heat together 5 oz. of rosin, 2 oz. of lard, and then add 1 oz.
of turpentine, and then 2 oz. of stearine ; boil to a suitable consistency.

4. Heat with care 7 lb. of wood tar with 5 lb. of rosin ; when the
whole is fused add 5 lb. of soft soap, then 3 lb. of cod oil ; remove
from the fire and stir till cold.

Use. — Cold coating compositions {Enduits) are used to protect
young buds from insects. Sorauer advises to cover them with a thin
layer which, whilst it drives off' insects, does not prevent the normal
evolution of the bud. It is an effective protection against Tortricides,
Tineides, as well as against weevils : Otiorhynchus, Magdalis, Peritelus,
and others. To prepare a very thin coating Henschel recommends to
dilute it previously with alcohol. Cold or hot coatings are used with
success to cover the wounds of trees.

Bird-limes have found a current use in replacing tar rings. Eings

352 INSECTICIDES, FUNGICIDES, AND WEED KILLEES,

of bird-lime are applied about o feet above the surface of the
ground. It may be applied directly on the bark of old trees. "With
young trees the treatment is risky. Hartig and Sorauer found that
thin-barked young trees are sensitive to bird-lime, and the bark, being
penetrated by it, the tree dies in a few years. When young trees are
to be protected, the trunk of the tree is encircled by a band of paper
11 centimetres (say 4^ inches) wide, which is coated with bird-lime.
It is well to keep the ring on all the year round and to renew it
whenever it loses its stickiness, say about every three months. The
ring of bird-lime is much more effective than the classical tar ring ;
like the latter, it retains all the apterous insects which ascend from
the soil on to the tree by the trunk, or which descend by the same
road to metamorphose in the soil. Thus the Cheimatobia hrimiata, L.,
and the Hihernia defoliaria, L., apterous phalena, the larva of
Eriocampa aclumhrata, and the Psylla of the pear-tree are easily
destroyed in that way.

Schizoneura lanigera, Hausm. (woolly aphis). — To combat this
aphis Clarac recommends to coat the spots invaded by colonies, that is
to say, all the bark, by a mixture made by heating 2 lb. of tallow,
3 lb. of rosin. 5 lb. of poppy or colza oil.

(3) Bouillies. — Rosin is added to increase the adherence of a
copper bouillie. The following formulae may serve as a guide : 1. Blue
vitriol 12 lb., lime 15 lb., rosin 6 lb., soap 7 lb., water 100 gallons.
2. Blue vitriol 12 lb., rosin 15 lb., soap 6 lb., water 100 gallons,

130. Camphor, C^i^H^^jO. — Natural Occurrence. — Camphor is
extracted in China and Japan from old camphor trees, Laurus cam-
phora, by sublimation — heating the roots and branches. It is refined
in Europe by fresh sublimation.

Properties, — ^Camphor is a white, semi-transparent, crystalline
substance. It has a characteristic, fresh, aromatic odour. Its density
is from 0-992 at 10° C. It melts at 173° C. and boils at 204° C, but
it volatilizes perceptibly at the ordinary temperature. Water dissolves
1 part in 1300 at 20° C. Alcohol and oils dissolve it freely. Camphor
is a poison of the protoplasma ; even in dilute solution its antiseptic
power is known. It has been used from the most remote times. It
has a poisonous action on the lower animals, chiefly the arthropodes,
which are killed by the vapours emitted by camphor at the ordinary
temperature.

Use. — Phylloxera vastatrix, Planch, (phylloxera of the vine). —
From 2-3 grammes of camphor run into a hole dug by a gimlet, as far
as the pith of the stock, and then corked, had a certain action on the
phylloxeras of the roots, but destruction was incomplete (legal process,
1872). Watering the ground round the stem with a bouillie of 10 lb,
of camphor, 25 lb. of ammonia, and 25 lb. of lime, had no good effect.

Mice. — To protect seed-corn from mice it suffices to mix it with a
little camphor before sowing it. The smell drives off the rodents.

CHAPTEE XXIII.

CARBON COMPOUNDS fcon^iwN^'d)— NITROBENZENE-CAEBOLIC ACID-
PICRIC ACID— CRESOL — SAPOCARBOL — CREOSOTE— CREOLINES—
LYSOL— POTASSIUM DINITRO-CRESYLATE— THYMOL -/3-NAPHTHOL
METHYL VIOLET.

131. Nitrobenzene, C^H^NOo. — Preparation. — By pouring very
slowly, whilst stirring, 1 part of benzene into a cold mixture of 2 parts
of nitric acid of 40° B., and 2 parts of sulphuric acid of 66° B. When
nitrobenzene is formed water is added till it separates. It is decanted
and washed several times with pure water, then with water to which
a little carbonate of soda has been added.

Properties. — Nitrobenzene is a yellowish liquid boihng at 213° C,
of a sweet taste, having the smell of bitter almonds. It is insoluble in
water, but soluble in alcohol, benzene, and oils. It is poisonous
(Olivier and Bergeron) ; the poisonous symptoms are the same as those
produced by aniline cyanose. The fatal dose for a man is 8-9 drops
(Letheby), 20 drops (Bardt).

Action on Plants.- — The experiments of Papasogli, Targioni-Toz-
zetti, and Del Quercio, have shown that soapy emulsions containing:
0-5-0-75 per cent of nitrobenzene, and soapy and alcoholic emulsions-
containing 0 •25-0-5 per cent, are not injurious to plants. Zechini and
Silva found, on the other hand, that a 2 per cent nitrobenzene emul-
sion is very injurious to the vine.

Action on Insects. — Nitrobenzene poisons insects. From the-
author's experiments the nitro group would appear to increase appreci-
ably, and in a general manner, the toxicity of aromatic compounds,
Papasogli found that a milligram of nitrobenzene, evaporated under
a cloche, killed all the eggs of the fly and of Bomhyx Mori. According
to the author's experiments nitrobenzene prevents the hatching of
chrysalides.

Use. — Papasogli recommends to destroy soft-skinned insects and
plant lice by an emulsion prepared thus : Dissolve 50 lb. of nitro-
benzene in 150 lb. of amyl alcohol, and add thereto 100 lb. of soft soap.
This insecticide is thinned down before use, and according to the
sensitiveness of the plant, with 10-20 parts of water, so as to get an
emulsion containing nitrobenzene 0-84-1-7 per cent, soft soap 1-7-3-4
per ceat, amyl alcohol 2-6-5-1 per cent.

Agrotis Segetum (grey-worm). — Papasogli recommends to water
beets with an emulsion of 5 lb. of nitrobenzene, 5 lb. of sulphuric acid,
in 9 gallons of water, to kill the grey-worm, the caterpillar of this
noctua.

ConckijUs ambignella, Hubn. (cochylisof the vine). — The caterpillar

(353) 23

354 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

is killed by an emulsion containing 2 per cent of nitrobenzene ; but of
that strength the insecticide is prejudicial to the vines (Zechina and
Silva). Dufour also found that the maximum strength of a soap
emulsion of nitrobenzene should be 2 per cent nitrobenzene and 3 per
cent of soft soap.

Schizoneura lanigera, Hausm. (woolly aphis). — Nitrobenzene
enters into the composition of an insecticide made in Switzerland,
" Knadolin," invented by Kraft and recognized by the Federal Depart-
ment of Agriculture for the destruction of the woolly aphis. It con-
sists of 2 lb. of nitrobenzene, 1 lb. of potassium xanthogenate, 40 lb.
of soft soap, and 60 lb. of amyl alcohol. It is not used in the com-
mercial condition but in aqueous solutions. With 1 lb. of Knadolin
one can, according to the effect desired, prepare 1-4 gallons of liquid
insecticide. It immediately moistens all the substances which it
touches, which renders it superfluous to clean the trunk mechanically
previously. To make sure of killing well-hidden insects, it is well,
against colonies of woolly aphis, to use the insecticide only diluted
with fifteen times its volume of water. Goethe remarks that Knadolin
does not attack the shoots and leaves of trees like sapocarbol and lysol.

Phylloxera vastatrix, Planch, (phylloxera of the vine). — Papasogli
recommends a mixture of 5 lb. of nitrobenzene, 5 lb. of sulphuric acid,
9 gallons of water, for the destruction of this plant louse (1876-1880).
The mixture is run into channels 8 inches deep between the stocks,
and closed up forthwith.

Cochineals of the Olive-tree. — Mottareale advises for their des-
truction an emulsion which he regards as very efficient, consisting of
nitrobenzene 0"25-0*5 per cent, soft soap 0-2o-0'5 per cent, water
99-50-99 -75 per cent.

132. Carbolic Acid, C,3H50H. — Preparation. — Carbohc acid or
phenol is obtained from coal tar, in which it is present to the extent of
3-12 per cent. When tar is heated carbolic acid distils, at the same
time as middle oils, between 150^ and 200° C. Strong caustic soda is
added to these oils, in which carbolic acid and its homologues dissolve.
"The liquid is treated by five times its weight of hot water ; the phenols
dissolve in the water, whilst the hydrocarbides remain insoluble. To
obtain carbolic acid it suffices to treat this liquor by dilute sulphuric
-acid, and to decant. Crude carbolic acid, containing its homologues,
is thus obtained. To purify it, it is washed with water, dried, then
distilled in cast-iron retorts, collecting the portion which passes beween
180' C. and 190' C, and crystallizing. Eectilication is not required
in the case of carbolic acid used as an insecticide, for the homologues
of carbolic acid are as insecticidal as itself.

Properties. — Carl)olic acid is a solid body, colourless in the pure
state, crystallizing in long needles. The slightest trace of water lique-
fies it. It is soluble in twenty times its weight of water, and volatile
at the ordinary temperature. It possesses a special odour and a burn-
ing taste. Carbolic acid is a powerful antiseptic, but it is also poisonous
and caustic. It coagulates albumens.

Action on Plants. — InjnrinuH. — Nessler has shown that young
plants die if an amount of carl)olic acid more than 0'012 per cent be

CAEBOLIC ACID. 356

added to their nutritive medium, likewise if pot plants be watered with
a solution of 0'3 per cent strength. A solution of 1 per cent is per-
nicious to cherry-tree and peach-tree leaves. Used to disinfect corn-
seed it does not lower the germinative capacity.

Action on Fungi. — As determined by Bull it requires a 5 per cent
solution of carbolic acid to coagulate the white of egg, gelatine, and
casein ; the precipitate is not a chemical derivative but a dehydrated
albumen, the carbolic acid being capable of being removed by washing.
The action of carbolic acid on the spores of fungi ought, therefore,
to be less energetic and more uncertain than that of copper salts which
yield with albumens stable insoluble compounds. The effect of
carbolic acid on saprophytic fungi such as PenicilUum glaucum has
been studied by Plugge. A solution of 1-1 "5 per cent kills them.
According to Neumann a 0"1 per cent solution in no way hinders the
germination of their spores, a 0"2 per cent solution retards this ger-
mination, and a 0"3 percent solution acting several times on the spores
ends up by kiUing them. Lemaire prevents the moist mould of flour
by a 0 per cent solution. Ferments are affected as follows by carbolic
acid : A solution of 1-2 per cent strength interferes with the fermenta-
tion. A solution of 5 per cent strength prevents it. The action on
bacteria is pronounced. Bucholz has shown that if a solution of
0"5 per cent strength interferes with their development, a 4 per cent
solution prevents their multiplication.

Action on Insects. — Carbolic acid is poisonous to insects; its
projjerty of coagulating albumen puts it on the same plane as metallic
salts endowed with the same property, e.g. salts of copper, silver, and
mercury, but this action is weak. As Bull has shown, a solution of
5 per cent strength coagulates white of egg, a 3 per cent solution only
rendere it turbid, and a 1 per cent solution leaves it limpid. Gelatine
and casein behave in the same way. According to Perroncito, the
eggs of Bombyx Moi-i, L., still hatch after steeping two hours in a 1
per cent solution of carbolic acid.

Use. — Carbolic acid has found several uses. It is used in aqueous
solution, in soapy emulsions, in admixture with silicate of soda, in
absorption by sawdust, by injection into the sap of plants, and in
spraying.

Use as Weed Killer. — Pammel recommends a 25 per cent
emulsion of carbolic acid in water to destroy Cnicus arvensis (char-
lock of Canada). The plant is cut 8 inches underground and the
. young shoots produced are washed afterwards with the emulsion.

Phoma Beta (disease of the leaves of the petiole of the beet). —
Carbolic acid plays the preponderant role in the disinfection of beet
seeds against bacterian and cryptogamic diseases. Kruger asserts a

1 per cent solution acts more surely than steeping for twenty hours
in a 0'4 per cent solution of blue vitriol ; for forty-eight hours in a

2 per cent bouillie bordelaise ; for eight hours in a (J-02 per cent mer-
curic chloride, and yet it does not lower the germinative capacity of
the seeds. The first experiments of 1890 made by Hellriegel consisted
in steeping for twenty hours in a 1 per cent solution of carbolic acid.
They yielded as a result of twenty experiments, 98 per cent of sound

356 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

beets against 13 per cent for the untreated. Steeping twenty houre
has been found too long, because it causes a delay of fifteen days in
the germination of the seed. By limiting the steep to fifteen hours,
even whilst using a 0"5 per cent solution, the result is the same, but
seeds withdrawn after ten hours only gave 50 per cent of sound plants.
To facilitate disinfection, Carlson advises to soften the seed for three
days in pure water of 17"5''-19°C., and only put them in the carbolic
acid afterwards when it acts quicker. Tarschebinski has made
numerous experiments which have confirmed those of Carlson. He
found that corrosive sublimate disinfected beet seeds without previous
steeping in water. Carbolic acid does not completely disinfect until
after steeping of the grain ; without that precaution disinfection is only
relative. He also found that carbolic acid destroyed the spores of
fungi much easier than bacteria. Wilfarth and Wimmer believe that
carbolic acid must be completely soluble in water to give favourable
results, and for that reason they prefer the crystallized acid of com-
merce.

Method of Disinfection. — After having perfectly dissolved the
carbolic acid in water the seeds are added ; they are stirred energetically
to moisten them uniformly ; the seeds are then pressed by boards and
weights so that they are entirely covered with liquid disinfectant.
After twenty hours' steeping the seeds are withdrawn and spread out
in thin layers in an airy place, where they are frequently turned.
The seeds so dried may be preserved as long as desired without that
being injurious to them. Mark advises for the disinfection a mixture
of carbolic acid and blue vitriol.

Potato Scab. — Frank and Kruger tried to disinfect the soil with
carbolic acid to overcome this bacterian disease of the potato. They
used an emulsion containing 250 grammes (0"55 lb.) of carbolic acid and
500 grammes of soap for a plot of 4 square metres. The result was
not so good as in disinfection by petroleiun.

Bacillus solanacearum (bacterial disease of Irish potato, and egg
plant, Solanum melongena). — Sackett recommends the disinfection of
potatoes and tomato seed by a 5 per cent solution of carbolic acid.

Bhizoctinia violacecB betce. — Eriksson found that disinfection of the
soil by carboHzed Hme appreciably diminished the number of these
fungi.

Uncinula Americana, How. (oidium of the vine). — Vesque, after
experiments to overcome oidium, found that carbolic acid of less
strength than 1 per cent does not destroy oidium, whilst 0*1 per cent
solutions are injurious to grapes.

Use against Insects. — Melolontha vulgaris, L. (cockchafer). —
To preserve strawberry plants from the larvae of the cockchafer, it is
advised to till along the borders and to sprinkle the hollows with a
0*1 per cent solution of carbolic acid.

Magdalis (enescens, Lee. — Against this insect which lives in the
bai'k of the apple-tree on the Pacific coasts, Chittenden advises to
coat the trunk in the springtime, up to end of May, with an emulsion
of carbolic acid, lime, and soap.

Anthonomus ])07ii()ram (apple blossom weevil). — Whitehead recom-

CARBOLIC ACID. 357

mends against this insect spraying with a sohition of soft soap 5 lb.,
carbolic acid 5 lb., in 100 gallons of water.

Tomicas dispar, Fbr. ("apple bark beetle," "shot-borer,"' "pear
blight "J.— In Canada this insect is prevented from laying its eggs on
the trunk of fruit trees by spraying on the trunks in spring a dilute
solution of carbolic acid.

Halticinece (altises).— To protect young kitchen garden plants
against the attacks of altises, spraying with very dilute carbolic acid is
recommended.

Atomaria linearis, Steph.— To drive olf this insect from young beet
plants, it suffices to disinfect the seeds as indicated on p. 345.

Eurydema ornatuvi, L. (decorated bug).— The red cabbage bug is
o.vercome by dusting the leaves with sawdust steeped in carbolic
acid.

Cossus ligniperda (the goat-moth).— Inject carbolic acid mto the
tunnels and stop the orifices.

Hyponomeuta malinella, Zell. (small ermine moth of apple-tree).—
In Italy 2 per cent tobacco juice, strengthened by a Httle carbohc acid,
is used to destroy the caterpillar of this butterfly.

Plusia gamma, L. [gamma moth of the cabbage). — Ashmead
advises to dust the cabbage for two to three days with a mixture of
phosphate of lime 20 lb., powdered lime 3 lb. , carbolized sawdust 1 lb.
Schizoneura lanigcra, Hausra. (woolly aphis).— Muhlberg found
that carbolic acid in this form, carbolic acid 4 lb., silicate of soda 100
lb., a mixture yielding an adherent jelly, kills the woolly aphis.

Chermes p)icecB and Mindarius abietinus (cochineals of the spruce).
— Boas got appreciable results by spraying with a solution containing
1-2 per cent of carbolic acid or 3-5 per cent of lysol.

PlujUoxera vastatrix, Planch, (phylloxera of the vine). — Mouillefert
declares that the phylloxera is killed by carbolic acid vapours although
slowly and bv contact. But carboiic acid is powerless to overcome the
phylloxera on the large scale. All the methods tried to attain this
end have failed; the Quehen-Mallet process, with a 0-2 per cent solu-.
tion of carbolic acid ; the Leonhardt process, using strong carbolic acid,
laid in holes pierced around the stocks, and the Anatole process, spraying
the soil round the stocks with an emulsion of petroleum and carbolic
acid, have all been failures. Dr. Manchon tried an original process
to poison the sap by making injections of dilute carbolic acid. Theo-
retically it could be granted that the descending sap carries the carbolic
acid to the roots and kills the phylloxera. Henneguy shows that it is not
so, as the phylloxera was not killed and the plant perished. A liquid,
whether poisonous or not, absorbed by the sap may circulate with it
and reach all the organs of the plant ; but there are products which
may be transformed by the sap itself, and consequently the insecticidal
action is not felt in spots distant from the point where they were in-
jected into the plant.

Liinithrips tritici (onion thrips).— Webster found that a 1 per cent
solution of phenol destroyed this thrips.

Tingis piri, Fl. (tiger of the pear-tree). — Dubreuil indicates dilute
carbolic acid as efficient against this parasite.

358 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Psylla Mali, Forst. (chermes of the apple-tree). — It is overcome
by a solution of carbolic acid 0-5 per cent and soft soap 0-5 per
cent.

Erlophya ribis (phytoptus ribis, currant gall mite). — It may
be overcome by a mixture of carbolic acid 3 gallons, soft soap 30
lb., in 500 gallons of water. First spraying in spring, second in
autumn.

/NO,

133. Trinitrophenol or Picric Acid, C^h//^q' . Prepara=

\0H
tion. — -Picric acid is the most important of the nitrated deriv-
atives of phenol (carbolic acid). It is obtained by heating carbolic
acid with an excess of fuming nitric acid or by pouring nitric acid drop
by drop into carbolic acid dissolved in sulphuric acid. Crude picric
acid, which separates from the liquid after cooling, forms crystals
which are collected. After draining they are dissolved in caustic soda ;
the picrate so formed is crystallized and decomposed by sulphuric acid.

Properties. — Picric acid crystallizes in yellow plates of a bitter
taste soluble in 86 parts of water at 15° C. and in 26 parts of water
at 77° C. It dissolves better in alcohol. Its salts are explosive.
Picric acid is used in medicine against intermittent fever {Dujardin-
Beaumetz and Clark). It has been recommended against trichinosis
and the solitary worm. It is of current use in treating burns. Picric
acid precipitates albumen in the same way as powerful insecticides ; it
is highly antiseptic.^

Action on Plants. — Experiments on this point are few; however,
trials on the vine show that the vine supports with impunity coatings
and washings of its roots. With a dose of 40 grammes per stock (616
grains) there is as yet no poisoning.

Use. — Picric acid has been tried in Gex-many as " Eeliorit," com-
paratively with blue vitriol, but w thout success, for the disinfection of
.seed-corn against Tilletia and Ustilago (Sigmund, 1896 ; Burmester,
1908). The corn was too sensitive to its action. The results obtained
by its use against mildew, oidium, cochylis, and chlorosis were negative
(Colmar Experimental Station, 1908).

Action on Insects. — The action of picric acid much resembles
that of " Antinnonine ". The first experiments on phylloxera were
made by Eommier. He found that by watering a vine in pot with
150 cubic centimetres of water containing 2 grammes of picric acid,
all the phylloxera were killed in a few days. Experiments on the
large scale did not give such a satisfactory result. Although each
stock received 40 granunes of picric acid in solution, although this
operation was followed by rains favouring the diffusion of the insecticide,
and although the earth was soaked with it to such an extent that it
tasted bitter, the phylloxera of the; lower layers were still living eighteen
days after treatment.

I Trannlator'a Note. — All iiitro dcriviitives mid tlu'ir MU'tallU: salts, more especi-
ally picric aoid and picrates, are highly exp'osivc, and tlicir storage is attended with
extremely great danger. A special licence is required.

SAPOCARBOL. 369

134. Cresol or Cresylol, C^,H^(^ p^r • — Preparation. — Cresol, a

methyl derivative of phenol (carbolic acid), is present in coal tar and
in wood tar. It is obtained in the distillation of tar at the same time as
phenol. Crude phenol is distilled and that which passes between 200°
C. and 205° C. is collected. It is an oil consisting in great part of
cresylol.

Properties. — Cresylol does not combine so readily with alkalies as
phenol, and is less soluble in water. It is an oil which has much re-
semblance with carbolic acid in physical, chemical, and antiseptic
properties.

Commercial Preparations containing Cresylol. — Cresylol is
rarely used as such, but mostly as its sodium derivative. It is an ingredi-
ent of the best known and most efficient insecticides. These are the
" sapocarbols," mixtures of crude cresylol and soap; the " lysols," mix-
tures of tar [oil] and soap; the "creolines," of analogous composition ;
" solutol,'' containing 15 per cent of cresylol, 45 per cent cresylate of soda>
in presence of an excess of alkali ; " solveol," of analogous composition
but neutral ; " amylo carbol," consisting of 150 oz. of black soap, 160 oz.
of amyl alcohol, and 9 oz. of cresylol; " thymokresol," prepared in
America ; " beech tar creosote," which contains along with phenol,
phorol, gaiacol, cresol, much cresylol. The composition of these various
insecticides differs greatly. They contain more or less cresylol accord-
ing to the source of the tars or the crude cresylols used in their pre-
paration. Like carbolic acid they all act on insects and on plants,
an action, however, which is more energetic but which varies much
from one product to another, according to the source of the cresylol.
There is thus much difference between the doses recommended as
killing insects without injuring the plants.

"35. " Sapocarbol." — This product, made in Brunswick, in Ger-
many,^ is a solution of homologues of carbolic acid in soaps. It is
made by heating a mixture of linseed oil, rosin, and potash, and the
oils collected in the distillation of crude carbolic acid, between 190° C.
and 205° C, oils which contain 10 per cent of cresylol, along with
xylenol, gaiacol, and other phenols. Alkali does not enter, except in
the small amount required to saponify the vegetable oils, in such a
way that the "sapocarbols" may be regarded as solutions of cresylols
in soaps. There are several brands of "sapocarbols". Their com-
position, very analogous to that of the lysols, is shown in Engler's
analyses. Table LXXIV gives the percentage of active ingredients
which they contain.

Properties.- — •" Sapocarbols" are neutral; diluted with water they
yield an emulsion from which the aromatic hydrocarbides separate
more or less rapidly according to the amount of soap present.

1 Transla tor's Note. — The mamifacture of this dass of goods is a British-born
industry which originated in the first instance in sheep-dip manufacture. Both
" Sapocarbol " and " Lysol " appeared on the Continent very hite in the day, and
neither their composition nor manufacture is based essentially on any very new
principle. The only real distinctive feature is the proprietary name, and if every
proprietary mixture of this sort, however meritorious it might be in itself, were to
receive the special mention " lysol " and " sapocarbol " do here, the special literature
would be more than unwieldy.

360 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

TABLE LXXIV. — Showing the Comparative Amounts of Active Ingredients iw
Different Brands of Lijsol and Sapocarbol Insecticides.

Insecticide.

Carbonate
of Potash,
Per Cent.

Phenols,
Per Cent.

Schenkel's sapocarbol No. 00

,, 0 .
„ 1 •

Lysol No. 1

^ ^^ 2

,, pure .....

2-6

7-7

7-6

5-91

6-29

6-52

37-3

37-<3
44-2
44-1
46-2
47-4

Action on Plants. — Fleischer found that sapocarbol acted as
follows : —

TABLE LXXV.— 4dio?^ of ''Sapocarbol'' on Plants.

1

Plants.

Solution,
1 Per Cent.

Sohition,
2 Per Cent.

Plum-tree and apple-tree shoots and leaves

Youns shoots of the vine

Adult leaves ........

Nasturtium ........

Nil
Decided

Nil

Injurious

Deadly

Injurious

Nil

Solutions of " sapocarbol " above 1 per cent injure most leaves
(Siedler and Koebele).

Action on Insects. — Fleischer examined the action on plant lice.

TABLE LXXVI. — Shnoing the Action of Solutions of " Sapocarbol " 07i Plant

Lice.

Insect Species.

1 Per Cefit.

2 Per Cent.

Woolly aphis, isolated .
,, ,, in colony
Plum aphis .....
Apple ,,

Killed

Partly destroyed

Killed

Killed

Destroyed almost entirely

Killed

Siedler, also Koebele, regard a 1-2 per cent as sufficient to destroy all
plant lice. Fleischer and Keller recommend sapocarbols to kill
plant lice, and even the woolly aphis ; in spring, by coating the nodo-
sities with a 2-3 per cent solution, by 1 per cent spraying in summer.
136. " Creolines." — Various " creolines " are differentiated : ^ —
Pearson\i " Crenline " is the product obtained by the saponification

' See Translator's Note to " S(i])orarbol " (p. 3.59). — Jej'es was the first to apply
the tsrm " creoline " to the active principle of this type of compound.

CBBOLINES.

361

of a mixture of higher phenols and coal-tar oil containing a small quan-
tity of pyridine bases.

Artmanns " Creoline". — Contains hydrocarbides extracted from
coal tar and completely freed from phenols, German patent 51515.
Whilst Pearson's " creoline " contains, along with 57-60 per cent of
hydrocarbides, 22-27 per cent of phenols, Artmann's "creoline" con-
tains 85 per cent of hydrocarbides, and only 15 per cent of phenols.

Properties. — " Creolines " treated by water yield an emulsion from
which the hydrocarbides present therein separate after a certain time.
Compared with lysols they have the great drawback of not yielding
stable solutions with water. Looking to their different phenol content
their action is very variable.

Action on Plants.- — Fleischer tested the action of Artmann's
"creoline " on plants and prepared the following table : —

TABLE LXXVII. — Shotving the Action of Artmann^s ^^ CreoUne^^ on Plants.

Plants.

0-5 Per Cent.

1 Per Ce7tt.

2 Per Cent.

Young shoots and leaves of
apple ....

Young shoots and leaves of
rose ....

Young shoots of vine

Adult leaves of vine .

Nasturtium leaves

Intact

Scarcely attacked

Greatly attacked

Intact

Damaged

Attacked

Damaged
Greatly attacked

Intact
Greatly attacked

Greatly attacked

Greatly attacked

Kilk d

Damaged

Killed

Action on Insects. — Fleischer tried Artmann's " creoline " on
plant lice :■ —

TABLE LXXVIII. — Actio?i of Art malm's " Creoll^te" on Plant Lice.

S])ecles.

Actioji of a Sohaion of

0-.5 Per Ce?it.

1 Per Cent.

2 Per Ce?it.

Woolly aphis, isolated

,. ,, in colonies
Willow aphis (naked)

Nil

Nil

Decided

Insignificant

Nil

Decided

Eapid
Partial
Decided

Goethe found a solution of soft soap better than one of " creoline ".

Use. — Disinfection of Seed Potatoes. — Mohr tried to disinfect
seed potatoes with " creoline ". By steeping twenty hours in a 0'2 per
cent of " creoline " their germination was retarded ten days. A more
concentrated solution had deadly effects. By diminishing the dose to
0'05 per cent and in adding 1 per cent of blue vitriol, not only was the
germination not retarded, but the crop was heavier, say 35'2 metric
tons with 13"9 per cent of starch against 21 6 metric tons with 17 per
cent of starch.

362 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Conchylis amhignella, Hubn. (cochylis of the vine). — Numerous
trials have been made. Zechini and Silva destroyed the vine-worm
by a 3 per cent emulsion. They obtained the same result with an
emulsion of 1 per cent of creoline and 1 per cent of nitrobenzene. Like
Dufour and Fleischer they found this treatment was very prejudicial
to the leaves and grapes. They therefore sought to discover other
mixtures, such as : —

TABLE LXXIX. — -Showing Composition of''' Creoline " Mixtures which gave Good
Results against Cochylis.

I.

II.

III.

Lb.

Lb.

Lb.

Creoline

1-5

1-5

1-5

Amvl alcohol ....

8

—

Tobacco juice ....

—

4

4

Soft soap . . • . .

—

—

1

Water

90-5

94-.5

100

These were quite satisfactory. Martini reduced the cochylis 65-68 per
cent by two treatments, one in the end of Api'il, the second in the
beginning of May, with an emulsion containing ] -5 per cent of Nava
creoline, 1 per cent of lime, and 1 per cent of blue vitriol.

137. Creosote [wood tar]. — Creosote is a mixture of different
phenols. Chemists who have studied the subject are divided in their
opinions as to its constitution. According to Marasse creosote con-
tains phenol, cresol, phlorol, ga'iacol, and creosol.

Preparation. — Creosote is extracted from wood tar, chiefly beech
tar, by distillation. The oily layer of the condensed liquid contains
creosote. This oily layer is again distilled, only the portions denser
than water are collected. When the product so obtained is treated
with a solution of caustic potash the hydrocarbides remain undissolved,
whilst creosote dissolves. Creosote is precipitated from its solutions
by sulphuric acid. Soot contains a certain amount of creosote.

Properties. — Creosote is a refractive, colourless, oily liquid, with a
smell of smoke and a burning taste. It does not d'ssolve in water,
but is very soluble in alcohol and in alkaline lyes. Creosote dissolves
resins and sulphur, coagulates the albumen of blood and of white of
egg. It is a strong caustic and one of the best organic antiseptic?, but
it has a poisonous action, like that of carbolic acid. It is used in the
state of vapour as a meat preserver, and in solution for the preservation
of wood, which it preserves both from insects and saprophytic fungi.
Its action on plants and insects is very analogous to that of carbolic
acid.

Use. — Merulius lacrymus, Schum. (rot of building timber, dry rot).
— " Carbolineum," consisting almost entirely of creosote, is recom-
mended against this fungus.

Haltica (altises). — Tlie bad smell of soot causes it to be used to
drive away altises. Thiele records several failures. Mohr recom-

LYSOL. 363

mends it as an insecticidal manure. The soot is spread on the field,
ploughed in, and crop sown eight to ten days later.

Sitones lineatus (striped pea weevil). — It is driven off by spreading
soot on the pea and haricot borders.

Ocneria dispar, L. (gipsy moth). — The mass of eggs of this buttei'-
fly are destroyed in America by the following mixtm-e : Creosote 50
per cent, carbolic acid 20 per cent, tar oil 10 per cent, turps 20 per
cent, the latter being chiefly used to dilute the creosote. Th;s method
is infallible. Experiments in America on 220 miles of land, by apply-
ing creosote on the eggs of this butterfly, followed by spraying with
arssniate of lead on caterpillars freshly hatched, have been crowned
with complete success, and have exterminated this formidable butter-

Abraxas grossulariata, L. (magpie moth). — In America soot is used
to destroy ihe caterpillars of the magpie moth. They pass the winter
under the dry leaves underneath the gooseberry bushes. These leaves
are removed and the soil round the shiubs covered with soot.

Agromiza niqripes (fly injurious to lucerne). — Debray recom-
mends to spread soot on lucerne plants to drive off the female about
to lay.

A2)hro])]iora spumaria, L. (grasshopper family). — Debray advises
to destroy the larvae in lucerne fields to cut the crop early and to
spread soot on the field.

Schizoneuralankjera, Hausm. (woolly aphis). — Landry advises the
use of the following mixture : Sulphur \ lb., soot 5 lb., tobacco juice 3^
lb., water 5 gallons. Apply by brush on nodes and fissures infested
by the lice.

PJij/Uoxera vastatri.r. — Mouillefert remarked the antiphylloxeric
properties of creosote, but it does not act on the soil at a great distance,
which renders its action uncertain and incomplete ; besides the toxic
dose for this louse kills the vine w^hich it should protect. Lustner
made experiments to determine if cresols communicate their odour to
the vine, and he concluded affirmatively. Wherever cresols were used
to replace petroleum in the disinfection of the vine against the phyl-
loxera, he found that the gi'apes possessed the taste of cresols within
a radius of 17 metres around the stock treated, a taste which is com-
municated to the wine in a very marked manner.

Cochineals. — Hering recommends to destroy these parasites by
coating the trunks of the trees in November with pure carbolineum.
This treatment does not damage the bark, but the eyes and the buds
touched are destroyed. Graf Wolstein concludes, from numerous
experiments, that all trees coated with pure carbolineum were freed
from all parasites, animal and vegetable, including cosstis, scolytes, and
woolly aphis. The gum of cherry-trees disappears'rapidly if the treat-
ment is repeated. Spraying with 2, 3, 8, 10 per cent solutions have
no effect except when the solutions are concentrated. Spring 2 per
cent sprayings have no effect.

138. "Lysols." — Preparation. — The preparation of Damman
" lysols " consists essentially in mixing in fixed proportions coal-tar oils
containing phenol and its homologues, w^ith an oil such as linseed oil

364 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

or rape oil, or with a resin such as rosin, by adding a base, preferably
caustic potash, in sufficient amount to obtain complete saponification.
The operation is conducted in presence of alcohol, which hastens
saponification and helps to render the " lysols " soluble and to impart to
them a suitable consistence. The proportions in the German patent
are linseed oil 10 lb., coal-tar oil 10 lb., caustic potash 30 per cent,
alcohol 6-i- lb. ; or rosin 10 lb., tar oil 4 lb. ? caustic potash 7 lb., alcohol
7 lb. Mix the linseed oil with the tar oil, add the caustic potash, then
the alcohol ; the mixture is heated to complete saponification in an
apparatus fitted with an ascending condenser.

Properties. — " Lysols " are liquid, brownish oils, transparent, and
soluble in water. Added to distilled water they form a limpid, mobile
liquid, with calcareous water they are turbid. The aqueous solutions
do not act on metals. "Lysols" are soluble in all proportions in
ethylic, methylic, and amylic alcohol, and may be mixed with benzene.
They possess a strong odour of creosote, and the antiseptic properties
of phenols without their defects.

Action on Plants. — " Lysols " are poisonous to plants, but they
are less irritant and caustic than carbolic acid. When absorbed by the
roots they are as injurious to plants as carbolic acid. Otto showed
that young maize and pea plants, raised in a nutritive media, suffered
much if the latter contained O'Oll per cent of " lysol," and died if they
contained 0'025 per cent. The nutritive medium in these experiments
remained neutral, or slightly acid. Trials on large scale show that
"lysol" used in 5 per cent solution to water soil before planting
hindered the growth of the plant. A 1 per cent " lysol " is injurious to
seed potatoes of one and a half hours' steep. Solutions of "lysol "■ —
even dilute — injure aerial parts of plants if a certain strength be ex-
ceeded, which varies with the sensitiveness of the plant from 04-3 per
cent. The most delicate plants support 4 per cent spraying ; rose buds
are injured by spraying with 1 per cent solutions of "lysol" and the
leaves with 2 per cent solutions ; the shoots of the apple-tree are burned
and the apples spotted by a 2 per cent solution. Fleischer has published
the following table : —

TABLE LXXX.-

-Shoiving the Action of " Lysol " Solutions of Various Strefigtlis
on the Organs of Different Plants.

Trees.

Organs.

0-25

0-5

1

3

Per Cent.

Percent.

Per Cetit.

Per Cent.

Apple

Young shoots and leaves

Almost
intact

Almost
intact

Attacked

Burnt

Rose

)> >i >)

Intact

Attacked

Far gone

,,

Vine

Youri}^ slioots

Almost
intact

Much
attacked

Burnt

"

Adult leaves

Intact

Intact

,,

,,

NHsturtium

Young „

"

"

Attacked

"

Action on Fungi. — The poisonous action of "lysol" on the spores
of parasitic fungi is not yet well determined. A 0'5 per cent solution

LYSOL.

365

prevents the germination of the spores of lilack rot (Eavaz and
Gouirand). It is much inferior to cupric and mercuric salts.

Action on Insects.^ — Perroncito found that a 1-5 per cent solution
acts bettt-r on the eggs of the mulberry bombyx than a solution of
corrosive sublimate of 0*5 per cent. Its energy is due to its soapy
nature, which surrounds the insects and their larvae and thus brings the
insecticide in direct contact with the vulnerable parts of the insect.
Insects generally succumb to a larger dose than that which is in-
jurious to plants ; thus the caterpillars of the cochylis touched by a
6 per cent solution do not die. Fleischer has summed up in the
following table his researches on the action of " lysol " on plant lice : —

TABLE LXXXI.

-Shoiving the Actio7i of " Lysol " Sohitions of Variozis Strc7igths
on Plant Lice.

Cojicentratioii of ^' Lysol" Solutions.

0-25
Per Cent.

0-5
Per Cent.

1
Per Cent.

3

Per Cent.

\

Woolly aphis treated iadividually

,, in colonies dipped

in solution ....

Green aphis (willow) treated in-
dividually ....

Green aphis in colonies dipped
in solution ....

Disturbed

Few attacked

Killed

All killed

Killed

Partly killed

Killed

All killed

Killed
All killed

Killed
All killed

Killed
AU kiUed

Killed
All killed

This table shows that a solution of "lysol" of 0-5 per cent kills plant
lice. " Lysol " is regarded by Fleischer as the best insecticide, and by
Sturgis as greatly inferior to emerald green (Paris green).

Use. — Sph<srotheca pannosa, Wallr. (blight of the peach and the
rose-tree). — According to Schiller, Lambert, and Griibe, a solution of
"lysol" of 0-5-1 per cent kills this blight. Constantin and Dufour ad-
vise " lysol " for the same purpose. The dose must be varied with the
delicacy of the rose or peach-tree. Ch. Charpentier circumscribes the
disease by spraying every eight days, and immediately the disease
appears with a solution of 3-5-4 per cent " lysol ". All the trees were
not radically cured by this treatment, but the disease did not increase,
and is not conveyed to the neighbouring sound trees.

Peronospora viticola, De By. (mildew of the vine). — Opinions are
much divided as to the efficiency of " lysol " against mildew. In a report
■ of the Wadenswiel Station, Switzerland, "lysol " is declared incapable
of overcoming this parasite. Dufour also regards it as inefficient ; it
gave no result ; its adherence to the leaves was also defective. " Lysol "
is regarded in Switzerland as inefficient and is not used. Sipiere, on
the other hand, advises its use in place of copper bouillies, and he has
praised its good effects. A "lysolage" with a solution of 0-5 per cent
gave him the same results as bouillie bordelaise, whilst it was also
cheaper. This treatment had also the advantage of overcoming oidium

366 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

and injurious insects. The first spraying was made with a solution
of 0-5 per cent, from 20-30 April. The second with 0-7 per cent
solution from 1-8 May. The third with 0-1 per cent solution from
1-8 June. Solutions of 0-5 per cent are very injurious to young
shoots, and 1 per cent solutions burn them ; but adult leaves stand
these strengths better and are not burned, except by those above 2 per
cent. To increase the adherence of this product it has been advised
to make a bouillie of 1 lb. of " lysol," 2-3 lb. of plaster, and ^ lb. of sili-
cate of soda of 33° B., in 10 gallons of water. The French "Lysol"
company sells a "lysol " powder recommended against mildew, which
must be used in the morning before the dew disappears.

Phytojjlithora mfestans, De By. (potato disease). — Sturgis declares
after experiments to disinfect potatoes with "lysol " that it cannot re-
place corrosive sublimate. " Lysol " in 1 per cent solution injures
potatoes in one and a half hours' steep. Its action on the spores is nil.

Fusarium. — Mangin advises against fusarium to disinfect the soil
with " lysol " in place of corrosive sublimate.

Guirjnardia BidwelU, Viala et Eavez (black rot of the vine). — -
Fernbach has studied the action of " lysol " on black rot. He records
the good condition of a vine coated in winter with a 3 per cent " lysol ''
solution and twice sprayed (1) with a 0-5 per cent solution at the be-
ginning of vegetation, (2) with a 0-7 per cent solution at the end of May.
Black-rotted leaves steeped in a 1 per cent solution for five minutes,
then washed and put in contact with a healthy leaf, no longer conveyed
the disease to the latter. It was the same with black-rotted leaves
placed in contact with a healthy leaf previously sprayed with a 1 per
cent preventive solution. Spraying and powdering done from bottom
to top, so as to reach the lower face of the leaves on which the parasites
preferably develop, arrest the disease in its evolution. Dieulafe advises
to overcome black rot : (1) The spraying of the stems, the runners, and
the pruning wounds with a solution of 2-5 per cent of "lysol," done
in winter at the time of pruning. (2) Spraying at the time ol coming
out in leaf of the buds with a solution of 0-5-1 -0 per cent. (3) Dusting
from April to August in moist weather with " lysol " powder.

Mycogone perniciosa (mole disease of the mushroom). — Constan-
tine and Dufour recommend "lysol" in 2 per cent solution for the dis-
infection of the frames. The process which consists in disinfection of
the whole frame, as much of the soil as of its sides, gives better results
than treatment with blue vitriol, boric acid, or bisulphite of lime and
sulphurous acid. It prevents or overcomes other diseases of the mush-
room such as the 'p\?hsier{MoniUafumicola),^p\\i (bacterian disease), etc.

Nectria cUtisslma, Tul. (canker of fruit trees). — Schiller remarks
that canker of fruit trees is cured quicker by " lysol " than by tar.

Coating Trees in Winter ag^ainst Insects. — Mathieu instead of
liming tbe trunks, coats them with a solution of i lb. "lysol"' in 1
gallon of water.

Char teas graminu (antler moth or grass moth). — Eeuter effectually
desti'oyed the cater])illar of this noctua by watering the meadows with
a 2 per cent solution of "lysol " when it begins its i-avages. " Lysol "
is regarded as less energetic against the caterpillars which live pro-

POTASSIUM DINITEO-CRESYLATE. 367

tected by gauze, such as the Hijponomeiita of the apple-tree, Lyda
Nemoralis, cochylis, etc. Barbut, using a 10 per cent solution, could
only destroy 20 per cent of the caterpillars of the cochylis and 26 per
cent of the caterpillars of the pyralis.

Cheimatobia brumata (winter moth, Evesham moth). — Kraft ad-
vises " lysol " as a very effective medium to overcome this butterfly.

Eurydema oleraceum, L. (kitchen garden bug). — Lampa reports
that after ten minutes these bugs are destroyed if the cabbages and
beets are sprayed with a 2-4 per cent solution of "lysol ".

Naked Plant-Lice. — Rossel recommends a 0-75 per cent solution
to destroy the rose aphis, a 1 per cent solution to destroy that of the
pear-tree and of the peach-tree. Kraf asserts that a 1 per cent solu-
tion kills all naked lice. Fleischer found that a 0-25 per cent solution
even killed lice in tightly packed colonies. On the other hand, Otto
commissioned by the " Lysol " factory itself to report on the efficiency
of its product, reports the inefficiency of 0"25-0'5 per cent solutions on
lice at the same time as their injurious action on the plants. How-
ever, the lice die in twenty-four hours when touched by a 2 per cent
solution.

Schizonezira lanigera, Hausm. (\voolly aphis).- — "Lysol " destroys
the woolly aphis, but, as Schoyen asserts, it is inferior to petroleum
emulsions. Whilst Hotter regards its action as doubtful, Eossel found
a 1 per cent solution perfect. Fleischer regards "lysol" as active at
0-5 ; at 1 per cent it desti'oys tightly packed agglomerations.

Cochineals. — Hertzog recommends 2 per cent " lysol " against the
kermes of the rose laurel. Frank and Kruger assert that "lysol"
solutions cannot kill cochineals.

Tetranychus telarius (red spider). — This acarus may be got rid
of by repeated spraying with 0'25-0'6 per cent solutions (Eathay and
Mussat). The iDrowning of the leaves of the vine is overcome by
spraying with 1 per cent solution of " lysol ". The acari of the genus
Eriophyes vitis especially attack the young shoots in the spring
which become atrophied. MuUer recommends to cut the young
shoots, destroy them, and coat the whole stem with 2 per cent " lysol ".
Thrijjs does not resist any better.

/NO.,

139. Potassium Dinitrocresylate, G^'H.2\ \ oT' " P'^^P^^'^tion.

— Potassium dinitrocresylate is used in Germany for the prepara-
tion of a powerful insecticide known as antinonnine, because it is
intended to destroy the caterpillar of the Liparis monaca [the black arch-
moth which attacks pines], called Nonne in Germany and in France.
Potassium dinitrocresylate is probably the crude product of the nitra-
tion of sulpho-conjugated cresylol or xylene by the action of fuming
nitric acid. Dinitrocresol is converted into a potash salt, soluble in
water by potash lye.

Properties. — Antinonnine, discovered by Harz and Von Miller, is a
mixture of equal parts of dinitrocresylate of potash and soap. It
forms a white crystalline paste soluble in water.

368 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Action on Plants. — A solution of antinonnine of 0"1-0'125 per
cent is without action on plants. When a stronger solution has to
be used on the tender parts of plants, it suffices to follow up the treat-
ment by washing twenty-four hours afterwards to prevent its action
on the plant.

Action on Insects. — -Antinonnine is poisonous to insects. A
small dose suffices to kill them ; it also acts on insects and soft-skinned
larvae ; cochineals, and certain carapaceous insects, such as weevils,
resist it (HoUrung). It is very poisonous to caterpillars, the larvae of
the tenthredes (saw-fiies), Ne?natus Bibesi, Thorsen (gooseberry saw-
fly), Lophyrus rufus (Schoyen), the thrips of grain crops, acari, plant
lice (Taschenbex'g), in doses of 0"125 per cent to 0'30 per cent.

Polyporus vaporarius, Polyporus destructo?-, Trametes cry2)tarutn,
or Polyporus Pini, Pers. (red rot of the pine). — Antinonnine has been
found an excellent means of destroying these fungi. Dilute solutions,
only containing 0'065 per cent of antinonnine, still produce the desired
effect.

Liparis Monaca, L. (the black arch moth which attacks pines),
(French and German sj'n. Xonne). — Antinonnine is regarded as a
specific against the caterpillar of the Nonne. An antinonnine solution
of 0'33 per cent acts in a categoric manner after twelve to twenty-four
hours ; 66 per cent of the caterpillars treated were killed after twenty-
four hours. By increasing the dose of soap the action is intensi-
fied.

CharcBcis graminis (antler moth or grass moth). — Keuter reports
the good etfect of a solution of \ lb. antinonnine and 1^ lb. soap in
10 gallons of water, against the caterpillar of this noctua at the time
when it appears in meadows.

Mice and Bats. — Antinonnine is a violent poison to rodents ; 0"5
gramme kills a rabbit. For rats and mice a mixture "is prepared of 10
parts of sausage grease and 1 part of sugared antinonnine. Mice die
after having absorbed O'OOl gramme, and rats after ingestion of 0'02
gramme of antinonnine. It suffices to soak pieces of bread with a
solution of sugared antinonnine, and to place it in winter in their
holes (V. Tubeuf).

/CH3(1)

140. Thymol, G,^.^<(-G.^.{^). — Preparation. — Thymol ispresent
\0H('3)
in oil of thyme. To isolate it the oil of thyme is agitated in a
strong solution of soda. The thymol is dissolved in the alkali.
This liquid is separated by decantation from the supernatant cumene
and thymene. The liquid obtained is diluted and saturated by hydro-
chloric acid which precipitates the thymol.

Properties. — In the pure state it forms colourless, crystalline
lamella', with a sharp and peppery taste. It is but slightly soluble in
water (1 in 1000), more readily soluble in alcohol and alkaline lyes.
It precipitates albumen and possesses remarkable antiseptic properties.

llypomyccs Pernicioaus, Magnus (mole disease of the mushroom).
— Constantin and Dufour recommend a solution of 0'25 per cent to
overcome the mole when the disease appears ; it is necessary to remove

yS-NAPHTHOL. 369-

all the horse dung, to disinfect the premises, and to plant afresh in new
dung.

141. /3-Naphthol, Cn,H-OH. — Preparation. — To obtain /?-naph-
thol from naphthalene it is necessary lirst to prepare the sodium salt
of ^-naphthalene sulphonic acid. It is prepared by heating together
equal parts of naphthalene and sulphuric acid at 200° C. The mixture
is run into water. The liquid obtained is treated with lime, boiled, and
filtered. The lime salt is converted into a soda salt by the addition of
carbonate of soda, filtering, and evaporating the liquid to a suitable con-
centration. The crystals formed are separated from the mother liquor
by centrifuging, and melted with 2 parts of caustic soda and the
water required to fuse the mixture. The temperature is raised gradu-
ally to 300° C. When the reaction is finished the product is dissolved
in water, hydrochloric acid added, and the precipitated yff-naphthol
collected on a filter.

Properties. — ^S-naphthol crystallizes in white lamellae ; it melts
at 122° C, and boils at 286° C. It is but little soluble in water, but
is soluble in alcohol and alkalies. It is antiseptic.

Action on Plants. — Soluble /3-naphfcho], in the form of its
sodic salt, burns the leaves ; the insoluble salts, on the other hand,
such as those of copper, iron, and lime, are not poisonous to
plants.

Action on Fungi. — According to Mangin a solution of naphtholate
of soda, 1 in 10.000, kills the spores of Bremia lactucce (lettuce mildew)
and Heterosjyormm echimdatum (fairy ring of carnations), but it is
without action on those of Nectria cinnabar ina (coral spot disease),
PeronosjJora arborescens, and Uromycds avicularice.

Use. — ;8-naphthol is- rarely used alone, but with soapy water, or in
the form of a soluble salt.

li- Naphtholate of Soda. — 144 grammes of ^-naphthol are beaten up
with hot water and caustic soda lye added to complete solution (100
gi'ammes of caustic soda of 44^ B.).

P-Naphtholate of Lime. — To \ gallon of a 5 per cent solution of
naphtholate of soda ^ gallon of milk of lime is added, containing 1 lb,
of lime. This bouillie is recomixiended by Mangin as a substitute for
lime for coating fruit trees.

f3-Naphtholate of Copper. — 4 lb. of /3-naphthol are dissolved in 3
gallons of hot water, containing 0-3 gallons of caustic soda of 36° B. ;
2| lb. of blue vitriol in 5 gallons of water are then added whilst stirring,
and the whole made up to 100 gallons of bouillie. This contains
naphtholate of copper, with great adherence, which does not injure
the leaves (Mangin).

(3-Naphtholate of Iron. — This bouillie is made like the preceding,
replacing the blue vitriol by 27 lb. of green vitriol.

Peronosjwra viticola, De By. (vine mildew). — Dufour tried naphtho-
late of soda against this disease without success. Mangin, however,
recommends a solution of naphtholate of soda, to which a little potato
starch [farina] has been added, so as to distinguish the spots treated,
Naphtholate of copper would be equally fit to combat mildew. The
soda bouillie decomposes on the leaves under the influence of the cai-

24

370 INSECTICIDES, FUNGICIDES, AND WEED KILLEKS.

bonic acid of the air into carbonate of soda and naphthol which is
very adherent to the leaves and resists heavy rain.

Gloeos^wrium viacrojous, Sacc. (orchid mildew). — Mangin advises use
of 2 per cent naphthol ; it prevents the germination of the spores.

Pojyj)!/ [CEillet] Disease. — Mangin recommends to steep before trans-
planting the end of the slips in a solution of 15 lb. of naphthol and 45
lb. of soap in 100 gallons of water or 5 oz. of naphtholate of soda in
624^ gallons of water (5 grammes in 10 litres).

Fusarimn roseuni. — Mangin advises the disinfection of the soil by a
solution of naphthol 1-2400. This method is disputed by Delacroix.
Sacardo advises with the same object a solution of 0'5 per cent of
naphtholate of soda against rust of poppies [CEillet], rose-bushes,
asparagus, etc.

142. Methyl Violet or Pyoctanine. — Pyoctanine is a methylated
or ethylated rosaniline obtained either by heating rosanilines to about
140° C. with methyl or ethyl chlorides or iodides dissolved in alcohol,
or by treating dimethylaniline by carbon oxichloride in presence
of aluminium chloride (yellow pyoctanine is a hexamethylated
auramine).

Properties. — Methylated and ethylated rosanilines in the form of
salts constitute crystallized violet colouring principles soluble in
water. They are used to make aniline inks, and in the dyeing of fabrics.
Pfeffer determined the injurious action of pyoctanines on phanerogams.
Kreminski, and especially Stilling and Wortmann, have examined the
antiseptic action of pyoctanines. They have shown that it suffices to
sterilize a medium, such as meat juice, for it to contain 0'005 per cent of
methyl violet, or 0'5 per cent of yellow pyoctanine. The Stajjhijlococcics
pyrogemis aureus does not develop in a solution of 1 in 2,000,000 of
methyl violet. The Penicillium glaucum does not develop in a medium
drenched with a solution of 1 in 10,000 of pyoctanine violet. The
pyoctanines do not coagulate albumens, like powerful antiseptics such
as corrosive sublimate, formol, etc., but albumenized bodies have a
certain affinity for these products and eliminate them from water whilst
becoming dyed. The colour concentrates itself there, and if the amount
absorbed is sufficient the corpuscles are arrested in their evolution, the
dyed bacteria give up their colour to pure water, and they can become
completely decolorized and regain by this fact their primitive vitality
if the surrounding water is in sufficient quantity to extract the colour
simply dissolved in their plasma.

Use. — Acrostalagmus albtts. — Stilling found that it sufficed to water
the infected dung or the dunged borders with a dilute solution of methyl
violet to stop the development of this fungus.

CHAPTER XXIV.

CARBON COMPOUNDS (contmned)— TOBACCO (NICOTINE TOBACCO JUICE)
—QUASSIA— HELLEBORE— PYRETHRA— DELPHINIUM (LARKSPUR)
—STRYCHNINE— NUX VOMICA— WALNUT LEAVES— GLUE— CUTCH
—ALOES.

143. Tobacco. — Tobacco is furnished by plants originally natives of
tropical America now acclimatized in all countries, chiefly Nicotania
tabacum and Nicotania rustica, L. When ripe the leaves of these plants
are collected and dried in drying machines. The green leaves contain
l'5-9 per cent of nicotine, the dry leaves up to 4 per cent.

Tobacco powder [? snuff] is made from greasy tobaccos. The
leaves are moistened with salt water, then cut into thongs and laid in
heaps of about 40 tons. Fermentation sets in ; after four months the
tobacco is conveyed to mills. It is moistened again and piled up to
undergo a second fermentation which lasts eleven months. Tobacco
juice is obtained in the tobacco manufactories by treating the coarselv
divided leaves with boiling water. The liquor obtained is filtered and
■evaporated to the right strength, then the substances injurious to plants
are removed. In France the cultui'e, manufacture, and sale of tobacco
are the subject of a monopoly exploited by the State. The Minister of
Agriculture publishes special sheets of information sent to the Mairies
(Town Halls), giving the price and the strength in nicotine of the juice
sold by this administration. The old juices are differentiated from the
new or rich juices ; the latter are five to six times stronger than the
former. The French tobacco administration now delivers the latter
with up to about 10 per cent of nicotine. They are sold to the public in
tins in the tobacco markets and in warehouses. Tobacco juice enters
into many insecticides to strengthen their action. A few examples only
will be quoted. To impart adherence to these insecticides gum-arabic,
sugar, etc., is added.

Insecticides with a Tobacco Basis. — (1) 5 lb. tobacco juice,
1 lb. soft soap, in 100 gallons of water. (2) Dissolve 4 lb. soft soap
in 10 gallons of water, then add, whilst constantly stirring, 6 lb. of
tobacco juice, 5 lb. of amyl alcohol, and 20 lb. of ordinary alcohol
(Nessler). (3) Dissolve 2| lb. of soap in 2 gallons of hot water, add
1^ lb. of amyl alcohol. Run into this liquor a decoction of 3 lb. of
tobacco juice in 8 gallons of water (Nessler). (4) Water 100 gallons,
rich juice, 10 per cent, 1 gallon, soft soap 10 lb., commercial carbonate
of soda in crystals 2 lb., methyl alcohol 1 gallon. The soap increases
its adherence and the wood spirit appreciably increases the action on
certain parasites. (Note of the French Minister of Finance regarding
tobacco juice drawn from the National factories for the destruction of

(371)

372 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

insects.) (5) Add to a 2 per cent tobacco juice a little carbolic acid.

(6) Add to 4 lb. of the above carbolized tobacco juice 1^ lb. of creoline,
1 lb. of soft soap dissolved in 10 gallons of water (Zechini and Silva).

(7) Dissolve 3 lb. of soft soap, in 5 gallons of water, add thereto a
solution of 2^ lb. of blue vitriol, neutralize by 11 lb. of caustic potash.
After stirring well run in 5^ lb. of tobacco juice and 2-^ lb. of " creoline ".

Properties. — Tobacco juice is characterized by a special alkaloid
nicotine. Pure nicotine is an oily liquid, colourless, soluble in water,
alcohol, and fatty oils ; it precipitates almost all metals from solutions
of their salts ; with copper it yields a green precipitate soluble in a large
excess of nicotine. Nicotine is a violent poison to mammals. A
single drop of nicotine suffices to kill a dog. It causes giddiness,
abdominal pains, followed by death in a few minutes.

Action on Plants. — Tobacco juice is used as an insecticide in
1 per cent doses, say 0"1 per cent of nicotine. It injures plants ;
mixtures with soap still further increase its injurious action. To
obviate this drawback it is necessary to follow the sprayings by care-
ful washing after one hour's interval. Fumigations in greenhouses
are less to be feared for the plants ; however, Decaisne has observed that
certain greenhouse (scrrefroide) orchids stand this treatment badly.

Action on Insects. — Nicotine is a violent poison for most insects
and their larvae. Chittenden observed that it did not act so on all
insects. A solution of O'l per cent (1 per cent of the rich juice of the
French manufactories), especially if it contains 1 per cent of soap,
forms an energetic liquid against the most diverse insects. If the
published results do not always agree that is due to the different
nicotine content of the juices tested on the same insects. It is agreed that
nicotine solutions have a specific action on the caterpillars of butterflies,
the false caterpillars of the saw-flies, on non-protected lice, thrips, and
acari In closed spaces the action of the vapours of nicotine is
drastic even on cochineals.

Use. — In enclosed spaces, greenhouses, or spaces covered in for
the purpose, the following process is used to obtain entire disinfection
of the plants therein : —

Fumigation or Evaporation of Nicotine in a Closed Space. —
It is carried out in different ways : (1) Tobacco is laid in a special
apparatus outside the greenhouse above red-hot coals, the combustion
of which is accelei'ated by a bellows. A pipe leads the vapours charged
with nicotine inside the enclosed space. (2) Moisten tobacco leaves and
place them on the hot pipes of the hothouse. The water evaporated
carries sufficient nicotine to kill the insects. (3) Slow evaporation
inside the greenhouse of tobacco juice placed on small stoves. (4)
Projection of tobacco juice on strongly heated bricks oi- irons.

Use in Open Air. — Open-air plants infested by insects are
sprayed with tobacco juice diluted with water to contain 1 per cent
of rich juice. Nicotine solutions not moistening sufficiently the insects
touched it is better to use soapy bouillies which adhere and moisten
much better and thus act more quickly. After one hour the insects
touched are dead ; the plants treated must then be washed to prevent
the deadly action of the nicotine and the soap on the plant.

TOBACCO (NICOTINE TOBACCO JUICE). 373

Tobacco powder spread by the bellows on the insects is very
efficient, and in many cases it is more active than pyrethra powder.

Haltica a77ipelophagus, Guer. (altise of the vine). — In the opinion
of d'Am-elles de Paladines tobacco juice of S'' B. black snuff mixed
at the rate of 12-15 per cent with Apt sulphur, a mixture of 1 per
cent of rich juice, 1 per cent of petroleum, and 1 per cent of soap forms
an insecticide which destroys the altise of the vine. Von Schilling
regards tobacco infusion as the most efficient medium against the altise
if the spraying be renewed after each rain. Thiele observes that these
preparations have no action on the altise unless the insects are touched
by the liquid ; the insecticide coatings which cover the leaves after
treatment do not remove the altise, hence the necessity of multiplying
the treatments to obtain a favourable result.

Altise of the Gardens. — When 3'oung • plants commence to shoot
up they are copiously w^atered and then wood sawdust strongly soaked
in dilute tobacco juice is spread over the whole of the seedlings.

Crioceris Asparagi, L. (the asparagus beetle). — Blin recommends
as very energetic a mixture of 10 lb. of tobacco juice infused in 30
gallons of boiling water, and 2-^ lb. of soft soap ; 66 gallons of this
mixture suffice for 2000 asparagus plants. This treatment completely
destroys the larvae.

Crioceris inelanopa, L. (crioceris of cereals). — Sajo recommends
tobacco juice, used as spray on infested fields. The following are the
results of a trial made with a solution of 20 lb. of tobacco juice, testing
Id'O per cent of nicotine in 10"6 gallons of water.

TABLE LXXXII. — Action of Tobacco Juice on Crioceris of Cereals.

Barley in Lb.
Plot treated with 154 gallons of this solution . . 199

Untreated plot ........ 78-1

Immune plot ......... 215 '6

There is no doubt of the good effect of this treatment. The operation
is best done at the moment the larvae are hatched. At that time
the field is sprayed in the direction of its width, then it is sprayed in the
direction of its length.

Bhynchites Fragaria. — This insect which cuts the strawberry
leaves is overcome by tobacco juice (0-5 B.), (Ernest).

Zahrus gihhus (carabe bossu), (cereal zabrus). — Three per cent of
Hungarian tobacco extract in 100 litres of water are perfectly capable,
according to Sajo and Naszay, of destroying this insect and its larvae
in wheat fields. The treatment is applied in the month of April ; the
stimulating effect is at once seen in the improvement in the growth
of the plant.

Cassida riridis (artichoke tortoise beetle). — Its larva gnaws the
leaves of the artichoke. Debray destroys it by tobacco infusion.

Sitones lineatus, L. (the striped pea weevil). — Noel advises tobacco
juice 0'5° B., and containing 1 per cent of soft soap.

Ocneria dispar (borabyx dispar, gipsy moth). — Berelse destroyed in
ifive days 100 per cent of the caterpillars of this butterfly with a 5 per

374 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

cent juice ; with a 2 per cent carbolized juice he only killed 80 per cent
of the caterpillars.

Abraxas grossulariata, L. (magpie moth). — Soapy solutions of
tobacco juice free gooseberry bushes from the caterpillars of the magpie
moth.

Conchylis amhignella, Hubn. (cochylis of the vine). — Nessler's
insecticides with a tobacco basis (formula No. 3) is perfect to destroy
the caterpillar of the cochylis. Zechini and Silva advise for the same
purpose their insecticide (formula No. 6). Jemina proposes his
insecticide (formula No. 7) to overcome simultaneously both the cochylis.
and mildew.

Hyponomeuta malmella, Zell. (small ermine moth of apple-tree). —
Sonnino praises 2 per cent carbolized tobacco juice.

Pentatoma (Carpocoris) baccarum, L. (bug injurious to fruit trees)..
— Taschenberg recommends to spread moist cloths in front of the fruit-
walls, and to fumigate with tobacco between these and the walls as is-
done in greenhouses.

Eriocampa adnmbrata (slimy caterpillar, slug-worm).— Bach re-
cords the good effects of tobacco powder spread on the larvae. Tobacco'
juice at the rate of 2 lb. of juice, with 14 "5 per cent of nicotine in 10'
gallons of water is regarded by Sajo and Czerhati as an excellent
method of destroying the slug- worm.

Nematus ventricosus, Kl. ; Emphytus GrossularlcE, Fb. (gooseberry
and currant saw-fly). — To get quit of this insect Ahlisch advises spray-
ing with a liquor consisting of 2^ gallons of tobacco juice, 5 lb. of
soft soap, and 40 gallons of water.

Lophyrns p)mi (the pine saw-fly). — Sajo advises to destroy the
larva of the pine saw-fly by spraying with a solution of 2 lb. of tobacco*
juice containing 14-5 per cent of nicotine in 10 gallons of water.

Diplosis rosiperda. — This rose cecidomia (fly), the larv£e of which is
in the rose shoots, is fought in greenhouses by fumigation with tobacco
(Chittenden).

Unprotected Plant Lice. — Plant lice are very sensitive to tobacco
juice. A solution of 0-1 per cent of nicotine, say 1 per cent of strong
tobacco juice containing 10 per cent of nicotine of the French State
factories, suffices to obtain a satisfactory result. However, the nature
of the lice prevents this liquid from moistening them, and these sprayings
only reach a small portion. To remedy this drawback, it suffices to
dissolve in the nicotine solution 1 per cent of soft soap. Laurent advises
soft soap and carbonate of soda. In these conditions the liquid at once
reaches the lice, which die forthwith. The operation must often be re-
peated, especially, as is frequently the case, when the lice have made
protective shelters by deforming the leaves, as is the case with the goose-
ben-y and peach louse. The soapy and alcoholic solutions (formulae
Nos. 3 and 4) are still better.

Schizoneura lanigera, Hausm. (woolly aphis). — Nessler's solution
(formula No. 3) is advised for the destruction of this aphis. According
to the researches of Stedman it would follow in an irrefutable manner
that the woolly aphis extends its ravages to the underground ])art of
the apple-tree ; to completely destioy the aeiial colonies the roots must

QUASSIA.

375

be disinfected at the same time. Gillette has studied the effects of
powdered tobacco [? snuff] in this particular instance. It is now re-
garded just as it is bought as an infallible specific for the destruction
of the underground form of this louse. Powdered tobacco mixed with
earth is frequently used in nurseries and also for other crops.

Phylloxera vastatrir, Planch, (phylloxera of the vine).— Mouillefert
found tobacco juice destroyed this aphis.

Tingis Piri, Fl. (tiger of the pear-tree). — Sajo advises 2 lb. of
tobacco juice containing 14-5 per cent of nicotine in 100 gallons of
water as a means of radically destroying the tiger, but care must be
taken to direct the jet on the lower surface of the leaves.

Pulvinaria vitis, L. {Coccus vitis), (vine scale).— Targioni-Tozzetti
advises to destroy the mobile larvae of this cochineal by spraying with
tobacco powder or using powders with a nicotine basis. Mohr praises
the effects of the following mixture deadly to cochineals in general :
Add 25 lb. of soft soap, 20 lb. of ammonia, 20 lb. of oleic acid per 100
gallons of tobacco juice. Guozdenovic records the good effects of a
mixture of 1-5 per cent of tobacco juice and 0-5 per cent of soft soap
against the Dactylopius vitis (white cochineal of the vine).

Thrips h(Bmorrhoidalis, Bche. (black thrips of greenhouses or
black fly of the gardener).— It infests plants in greenhouses, and under
cloche, "such as azaleas, camelias, fuschia, and causes them to fade.
It may be overcome, according to Decaisne, by powdered tobacco and
fumigations. Noel advises to soak the residues from the manufacture
of tobacco in a solution of 2 lb. of nitrate of potash in a gallon of water
and then dry it and burn it in the hothouse.

Limithrips Tritici (thrips which ravage onions). — It may be
destroyed, according to Webster and Rathay, by a decoction of tobacco.

[Animal and plant lice are effectively treated by tobacco juice.]

PJujllocoptus Schlechtendali, Nal. (browning of the leaves of the
pear-tree).— This acarus may be destroyed, according to Sirodot, by
tobacco juice marking 1-5° B. and sprayed on all the parts of the tree.

Greenhouse acari do not stand fumigation (Decaisne) nor spraymg
with the mixture of ammonia, tobacco juice, soap, and oleic acid to be
used against vine scale (Mohr).

Tetranyclms telarius (red spider).— Rathay kills this tree louse

with tobacco juice.

Tetranyclms althaece (Tetranychus which causes the rustmg of
the leaves of the hop), (Kupferbrand). It is overcome, according to Voss,
by preventive treatment. In the autumn the soil is dusted with
powdered tobacco [? snuff]. Spraying with tobacco juice has
Uttle effect on adult tetranychus living on the plant (Sorauer).
Voss' method is preventive. It kills the tetranychus which hibernate
under the leaves on the hop fields and prevents the return of the
disease. .

144. Quassia Amara , true.]— Quassia is derived from a Guiana
tree, the quassia tree [Quasma Amara]. The quassia of the shops is the
wood of Picrena Excelsa, belonging to the family of Simarubiacece.
The wood and the roots are sold as chips or lumps (Lignum QiiassiC(E).
To extract the quassia the chips are macerated for twenty-four hours
in water. Insecticides with a quassia basis are prepared thus : (1) r>oil

376 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

on the one hand, 5 Ih. of quassia chips in 50 gallons of water ; let stand
for twenty-four hours and decant the extract ; on the other hand, dis-
solve 5 lb. of soft soap in 50 gallons of water. Mix the two liquids.
(2) 7^ lb. of quassia are macerated and 3^ lb. of soap are dissolved
in 100 gallons of alcohol (Alvood). (3) 1-^ lb. of quassia are macerated
in water, heated to boiling and decanted ; after twenty- four hours a solu-
tion of 2^ lb. of soft soap is added and the bulk made up to 10 gallons
(Klein). (4) Dissolve 10 lb. of soft soap in 5 gallons of hot water,
add thereto an infusion of 2^ lb. of quassia chips obtained by twelve
hours' steeping in 5 gallons of rain water ; make up to 40 gallons
(Koch's insecticide). (5) Emulsify 5 gallons of petroleum in a solution
of 6 lb. of soft soap in 50 gallons of water (see petroleum), and add
thereto an extract of 10 lb. of quassia in 50 gallons of water. (6) Add
4 lb. of carbolic acid to a mixture of 5 lb. of quassia extract and 6 lb.
of soap in 100 gallons of water (Gilardi).

Properties. — Quassine, the active principle of quassia amara, is
amorphous or crystalline. It has been isolated by Winkler. It is
colourless, inodorous, opaque, and inalterable in the air, slightly soluble
in water, much more soluble in water charged with salt or organic
acids, and in alcohol. To man, quassine is not poisonous, it is toxic,
aperient, and stomachic. In doses of 4-10 centigrammes per day,
quassine has no injurious effects on man ; on the other hand, it is
deadly to the lower animals — oxyures, ascarides, etc.

Action on Plants. — Plants are not injured by spraying with
aqueous extracts of quassia ; on the other hand, extracts mixed with
soap are injurious to certain plants, especially if soft soap be used and
if the dose is superior to 1 per cent. Fleischer prepared the following
table on this point for Klein's solution (No. 3 supra) : —

TABLE LXXXIII. — Showing the Action of Klein's Solution (3) on the Organs

of Various Plants.

Plants and their Organs. Action.

Shoots and leaves of the apple-tree .... Hardly attacked

Leaves of the plum ........ ,, ,,

Vine .......... Unattacked

Nasturtium ......... Greatly damaged

Action on Insects. — No insect can live in boxes made of quassia
wood (Wright) ; tiy-paper is blotting-paper soaked with a sugared extract
of quassia. Quassia insecticides act on soft-skinned, non-protected
insects, on their larvtc, on caterpillars, plant lice, and phytotides.
Koebele regards quassia extracts as less active than fish-oil emulsions.

Use. — Caterpillars of Fruit Trees. — Insecticide (5) is recom-
mended by Gilardi as an excellent medium for destroying various
caterpillai's which infest fruit trees.

Conchylis amhiynclla, Hubn. (cochylis of the vine). — Insecticide
No. 1 is regarded by Gilardi as sufificieat to destroy the caterpillar of
the cochylis.

Unprotected Plant Lice. — Plant lice are very sensitive to quassia
extracts. Whitc^head i-econiuiends insecticide No. 1 against the hop
aphis and the wheat aphis ; Klein and Fleischer insecticide No. 3

HELLEBORE. 377

against greeu aphides and even against the woolly aphis. Mohr the
insecticide No. 1 against the aphis of the peach and of tlie gooseberry,
to be used when the leaves begin to uncurl.

Phijlloxera vastatrix, PI. (phylloxera of the vine).- — Mouillefel't
regards quassia as inefficient against this louse. In Germany, Schmidt
has taken out a patent, D.E.P. No. 50772, for a mixture to be used to
destroy the phylloxera of the vine, the composition of which is methyl
alcohol 30 parts, turpentine 10 parts, extract of quassia 3 parts, or
methyl alcohol, 60" Tralles, 10 parts, carbonate of potash dissolved
in water 1 part, quassia extract 1 part, phosphoric acid, 20^ B., 1 part.

Phytoptus Bibis, W. — A liquor made from 4 lb. of quassia chips
and 3 lb. soft soap, in 50 gallons of water, used as a spray in the spring
and in the autumn as soon as the fall of the leaf, destroys these
msects.

PJiytocoris militaris, Westwood (orchid bug). — Staes has shown
that tobacco powder had no action on this bug, but that, on the con-
trary, a decoction of quassia with soft soap destroyed them.

145. Hellebore Root. — Hellebores, plants of the family Eenon-
culaceae, contain a bitter substance which imparts to them violently
drastic properties and renders them poisonous in large doses. It is
chiefly the roots which contain this principle.

Preparation of the Liquid Insecticides.— (1) 5 to 1\ lb. of finely
pulverized hellebore roots are stirred up in 100 gallons of water ; this
bouillie is used such as it is without being decanted. (2) The powder
obtained by finely pulverizing white hellebore roots is diluted with up
to 10 parts of flour ; at the fall of the dew it is spread on the plants by
means of a bellows or through a muslin bag. (3) Make a decoction of
1 lb. of hellebore root and let it stand twenty-four hours. (4) Emulsify
60 fluid oz. of paraffin oil with a solution of 120 oz. of soft soap in 10
gallons of water, then incorporate 40 oz. of hellebore root (Whitehead).

Action on Insects. — Hellebore root is a violent poison to insects
which gnaw leaves, it acts like arsenical salts and is used in their
place.

Use. — Insecticides Nos. 1 and 2 appear according to Whitehead
and Eiley to be specific against : —

Eriocamya adumbrata, Eriocamjm cerasi (the slimy caterpillar,
slug- worm).

Nematus Bibesii, Scop, (gooseberry saw-fly).

Cladius j^ectinicornis, F., Emphytus cinctus, L., Monostegia Bosce,
H. (rose saw-fly).

Abraxas grossulariata, L. (magpie moth). — Emulsion No. 4 is
recommended by Whitehead against Psylla, Anthonomiis pomorum
and Sdiizoneura lanigera (woolly aphis).

SjJarroivs. — To poison sparrows, it suffices to place a handful of
hellebo]'e powder in 1 quart of water and boil gi-ains of wheat therein.
The sparrows eat them without suspicion.

Bodents. — Constantin Cesar recommended in 1543 to place in rat
holes during great heats (1) a mixture of rye grain, barley-meal, and
hellebore, or (2) a paste made by grinding equal parts of bitter almonds
and hellebore, and afterwards mixing with barley-meal and oil.

378 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

146. Pyrethra. —The pyrethras, plants which belbng to the family
of Composita?, contain an insecticidal principle. Two plants are chiefly
used to make pyrethra powder or bug powder ; these are Pyrethra
cineraria-folium, Treviv., and the ChrysantJiemum coccineum, Willd.
A species originally Caucasian, Pyrethrum roseiim, contains less active
principles. Although cultivated in Asia, insecticidal pyrethra can
accommodate themselves to the South of Fi-ance. Their culture might
produce excellent results with a profitable yield.

Preparation of Pyrethra Powder. — The flower, the sole organ
of the plant containing the insecticidal principle, is alone ground,
xlccording to certain authors the best powder is made from unexpanded
flowers ; others say that the flower-bud must be perfectly closed, whilst
others assert that the flowers should be collected when the flower is in
full bloom. Pyrethra powder is made in America, Great Britain,
Germany. Montenegro exports into these countries 10 tons of pyrethra
flowers per annum. Pyrethra powder is none other than the dried
flower suitably and finely pulverized. It is used most often alone,
such as it is ; sometimes it js mixed before use with three times its
weight of flour, or with four times its bulk of sulphur to destroy both
the altise and the oidium of the vine, or again with cupric sulphosteatite
to destroy the altise and the mildew.

Preparation of Pyrethra Extracts. — 1. Aqueous Extracts. —
6 lb. of pyrethra powder are treated cold with 10 gallons of water.
Maceration lasts twenty-four hours. It is easier to make the extract by
aid of heat. The pyrethra powder is first made into a paste by hot
water, it is thinned down gradually with boiling water and cooled.
Before use this extract is diluted with six to eight times its volume of
water without losing its insecticidal properties.

2. Soap Extract. — Dissolve 3 lb. soft soap in 1 gallon of hot
water ; add thereto whilst stirring with a birch-broom 1\ lb. of
Dalmatian pyrethra powder and 9 gallons of cold water. Invented by
Dufour of Lausanne, this insecticide is one of the most perfect now
existing.

3. Alcoholic Extract. — Treat 6 lb. of pyrethra powder with 10 gallons
of 80 per cent alcohol. Dilute before use with 5 parts of water.

4. Alcoholic and Ammoniacal Extract. — Mohr mixes in a flask
100 grammes of Dalmatian pyrethra powder, 200-250 grammes of
alcohol, 80-100 grammes of commercial ammonia. After some days
he adds 1-^-2 litres of water, and heats gently for forty-eight hours.
[Similar proportions in the same ratio are 1 lb. pyrethra powder,
2-24 lb. alcoliol, 0*8-1 lb. commercial ammonia, and 1^-2 gallons of
alcohol] The liquor is filtered and mixed as follows : —

TAIU;I<i IAX\IV. — SlioiiHiiii Composition of I'tjrethra Insecticides.

No. I. No. 2.

Extract 3 lb. .■) lb.

White soap 2^ ., 5 „

Non-calcareous water . . . .10 (^iils. 10 gals.

Preference must be given to one or other of these insecticides accord-
ing to the resistance of the insect to be killed.

PYRETHRA. -^79

5. Cupric Insecticide Bo u i II ic— Treat by boiling from five to
ten minutes or by maceration for twenty-four hours in the cold,
3-4 lb. of pyrethra powder in 10 gallons of water, and mixing this
extract with a cupric bouillie by running it into the concentrated
bouillie. This bouillie has the advantage of acting both on the mildew
and the altise of the vine simultaneously.

6. Alcohol and Carbon Disidphide Extract.— 1rez.i 7 oz. of
pyrethra powder by maceration for eight days in a mixture^ of 7 oz. of
ether, 25 oz. of carbon disulphide, and 75 oz. of alcohol, 86° B. (all by
weight). Filter afterwards (Pratigeon).

7. Pyrethra-petrolevm Emulsion.— ^mulsiiy petroleum in an
aqueous pyrethra extract. This emulsion is recommended by Webber
against cochineal.

Properties. — Pyrethra powder forms a very fine light powder,
the insecticidal principles of which are volatile. Old powders are
dead and inert.

Action on Plants. — Pyrethra powder has the great advantage
over insecticides, such as petroleum, carbolic acid and others, of having
no injurious action on the leaves ; even the soapy extracts if they do not
contain too large a dose of soap are without injurious action on plants.
(Fleischer).

Action on Insects.— The intensity of the action depends on the
freshness of the pyrethra powder. The insecticide action of th&
powder sold under the name of bug powder has been known for a long-
time. If it be not preserved in a well-closed bottle, its insecticidal'
power departs ; moreover, its action is of very short duration, the active
principles being very volatile. Carapaceous insects are generally in-
sensitive to this insecticide ; it is not so with soft-skinned insects and
larvffi not protected by a hairy down, these succumb readily. The-
different soapy and alcoholic extracts are much more active owing to-
the substances which they contain, which moisten the insects touched
more perfectly than aqueous extracts.

Use. — As powder pyrethra is in domestic use to treat plants in pots
infested by lice and to free them from vermin. The extracts would
find an extensive use if they were cheaper and their action less vari-
able according to whether the pyrethra bought is fresh or old.

Leptinotarsa decemlineata (Colorado beetle). — Alvood found that if
the powder is inert against adult insects, it kills 50 per cent of the
larvae.

Sajyerda Populnea, L. (the poplar borer).— To destroy the larvie
of this Coleoptera, Mohr advises to inject his extract No. 4 (p. 378) into
their burrows by means of a caoutchouc drill ginded by an iron wire..
The amount should be such that the liquid flows from the orifice. After
a quarter of an hour all the larvas leave the holes and can be cru^hed.^
The same process is used to destroy the caterpillars of Cossus and of
Sesia ; the latter dies in the holes.

Haltica ampelophaga (altise of the vine).— P\a-ethra is regarded
as an excellent medium for getting quit of the altise of the vine, and
altises in general, 12-15 percent of pyrethra powder with ordinary
sulphur or Apt sulphur to overcome simultaneously the oidium and

380 INSECTICIDES, FUNGICIDES, AND WEED KILLERS,

-altises. Gervais advises to mix pyretlira powder with ' ' Cupric-sulpho-
•steatite ''. Two applications suffice to get quit of this minute insect.
Pyrethra extract may Ukewise be added to cupric bouillies. The
extract alone is used at 4 per cent strength. Debray, Prosper, Gervais,
Lecq, and d'Aurelles de Paladine report the terrible action of mixtures
containing pyrethra. Taschenberg and Montillot advise to kill in a
general w^ay all earth lice by using mixtures of pyrethra powder and
naphthalene; naphthalene 2 lb., pyrethra powder 1 lb., or pyrethra
powder alone.

Lema melanopus, syn. Crioceris melanopa (crioceris of cereals). —
"To kill the larvae of this insect injurious to grain crops in Hungary,
Sajo recommends to spray copiously with aqueous pyi'ethra extract.
This process destroys 75 per cent. Nicotine is regarded as more
■active.

Entomoscelis adonidis, Pall. — Sajo advises 2*5 per cent pyrethra
extract to destroy i^apidly the larva of this insect which gnaws the leaf
of the beet.

Conchylis amhignella, Hubn. (cochylis of the vine). — The soapy ex-
tract of pyrethra with 3 per cent of soap was recommended (p. 378) by
Dufour to kill the caterpillar of this butterfly. The first spraying must
be given before flowering, when the caterpillars have just hatched, and
the second after flowering. In the opinion of Perraud, Berlese, Silva,
Bononi, Nestore, Peglion, and Del Quercio it is one of the best means
'of killing the red-worm of the vine. It has, however, the disadvantage
of being dearer than other insecticides. Sirodot recommends its
application by a spraying machine, with an intermittent jet, which is
directed on to the grapes morning and evening in the month of Jul}'.

Carpocapsa j^omonella, L. (codlin moth). — Mohr recommends
bis No. 2 extract (p. 378) applied before flowering, to destroy the young
caterpillars of this pyralis.

Eriocampa adumbrata (slimy caterpillar, slug- worm). — Dufour's
soapy extract of pyrethra (p. 378) gives good results in the destruction
of the slimy caterpillar (Siedler).

Hylotoma rosar urn, Fabr. (hylotomeof the rose). — Mohr recommends
his No. 1 extract (p. 378) against the false caterpillar of this saw-fly.
Taschenberg reports the good results from a mixture of 66 per cent of
pyrethra powder and 33 per cent of naphthalene against the larvae of
saw-flies in general.

Athalia Spinarum (Athalia centifoiia), [the turnip saw-fly, black
-caterpillar, blacks, canker, black palmer, nigger or black grub], Fabr. —
This saw-fly, the larvae of which ravage the leaves of beets, may be
destioyed, according to Burki, by an aqueous mixture of 4 per cent of
soft soap and 1 per cent of extract of pyrethra powder.

Jjopus sulcatus, of which there was an invasion in 1889 into
the departments of Indre and Yonne, may be destroyed, according to
Praligeon, by the alcoholic and carbon disulphide extracts of pyrethra
refened to above.

Diplosis rosirora. — This rose-fly gnaws the shoots of the rose-
bush, esp!'cially those of La France, Meteor, and Wooton. Chittenden
:recommends pyrethra powder to combat it.

STRYCHXINE. 381

Dijylosis riolicola, Coq. — It is killed in the same way (Chittenden).

Ants. — Taschenberg recommends to kill them with a mixture of
pyrethra powder and naphthalene. Mohr advises his extract (p. 378)
at the rate of 30-35 fluid oz., diluted with 250 fluid oz. of water and
poured on the ant nest in the morning before the ants come out. In
light soils and with large ant nests, it is necessary to poui' 1-2 litres
of this liquor, say 1 to 2 quarts.

Schizoneura lanigera, Hausm. (woolly aphis). — Grossbauer re-
commends to destroy this parasite with a mixture of soft soap 7-j lb.,
pyrethra powder 2\ lb., in 100 gallons of water. Muller found this
liquor less energetic than Nessler's insecticide at -J^y.

Naked Plant Lice. — According to the experiments of Fleischer,
the soapy extract kills them easily. Hotter recommends the powder,
tecause it can penetrate into the t\%'isted, rolled, and dt'/Ormed leaves-
which serve as a refuge to many plant lice and surely reach the latter.

Psyllas and Phytoptides (gall mites) are destroyed in the same
way.

Slugs. — Mohr recommends his extract No. 2 (p. 378) to kill slugs.

147. Strychnine. — Strychnine is an alkaloid which is contained
in certain plants such as the nux vomica tree, which yields nux
vomica, and the walnut-tree.

Use. — Spilographa Cerasi, F. (cherry-tree fly). — Water the soil
around the trees after the fall of all the wormy cherries with a hot
decoction of walnut leaves that kills the gi'ubs buried at a slight depth
in the soil (Taschenberg).

Plant Lice. — Kasebier recommends the follo^ving liquor to get
quit of these lice : Make an extract of rasped nux vomica nuts by
passing them three to four times into hot water, then letting them
macerate some hours. To preserve this extract, J^^ per cent of de-
natured alcohol (meth. spirit) is added to it when about to be used ; to
strengthen its action 1 per cent of " sapocarbol " is added to it. No
insect, it would appear, frequents a tree spraj^ed with this liquid
insecticide.

Phylloxera vastatrix, Planch, (phylloxera of the vine). — Syringing
with strychnine solutions (Mourgue's process) had no more effect on
this louse than an infusion of ^ lb. of walnut leaves in a gallon of water
(Chevalier's process, 1872), or of \ lb. of walnut leaves in a gallon of
water (Panet's process, 1872).

Peach and Gooseberry Aphis {Ajyhis pcrsicce). — An infusion of nut
leaves collected in autumn destroys these plant lice, especially when it
is strengthened by a little soap. Mohr advises to spray as soon as the
leaves begin to curl and twist ; he sprays twice.

Sparrows. — Granivorous birds may be prevented from devouring
corn-seed by dipping the latter into a bath containing strychnine ; dis-
solve 10-15 grammes (say J to ^ oz.) of strychnine in the water
required to cover entirely 1 kilogramme (2*2 lb.) of seed ; steep the
grain for two hours, stirring occasionally, then withdraw it and dry it.
Kruger remarks that if the birds devour it the first day none reappear
the following days.

Talpa e^iropea (mole). — To destroy moles it suffices to cut up earth-

382 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

worms into pieces and to roll them in nux vomica powder, and to place
them in their burrows.

Rodents. — It is advised to poison wheat by strychnine, and to
place it in pipes in proximity to the burrows of the rodents. The pipes
prevent birds from being poisoned.

148. Delphinium (larkspur). — The extract from the stems, leaves,
and seeds of the larkspurs, especially that from the seeds of Delj)hinium
grandiflorum and Delphinium ajacis, is recommended for the destruction
of insects. Powdered larkspur seeds are used in medicine to destroy
vermin in the head and to cure skin diseases ; extract of larkspur taken
internally is drastic, emetic, aperient, diuretic, and vermifuge. Laboul-
bene advises larkspur extract to destroy grey-worm, the caterpillar of
Agrotis segetu?^^ L. The young plants must be copiously watered with
this extract.

149. Glue. — Glue made from animal matter may be used to
overcome the diseases of plants and animals.

Use. — Peronospora viticola, De By. (mildew of the vine). — Vesque
asserts that solutions of glue cure the vine, but the treatment injures
the development of the grape.

Schizoneura lanigera, Hausm. (woolly aphis). — Del Quercio de-
clares that an excellent method of destroying this louse consists in
coating the colonies with a mixture of 1^ lb. of glue and 3 gallons of tar.

150. Catechu or Cutch. — This astringent substance, extracted
from a species of Indian acacia, stops, according to Vesque, the develop-
ment of the oidium.

151. Rose Laurel. — The infusions of this plant of the family of the
ApocynacecE are used in medicine against scab. According to Debray
the rose laurel is macerated, in Algeria, for several days and the putrefied
liquid used to destroy insects, chiefly the mole-cricket.

152. Aloes. — Aloes is the resinous juice, extracted from the leaves
of several species of aloes. It is bitter and nauseous. It is used as a
tonic, purgative, and drastic. In Tunis there is added to bouillie
bordelaise, intended to kill the Peronospora, 1-1-3 lb. of aloes per 100
gallons of bouillie, so as to destroy altises simultaneously.

[The End.]

GLOSSARY.

Abkaxas grossdlariata, Leaeli. Phal-
enu i/mssu/uriatu, L. Coiumou names :
Euglisli, the magpie moth ; French, Arle-
ijuiii, I'halene, or Zereae du Gmsei/lier. —
White and yellow caterpillar, with some
black spots, which after the end of summer
ravages goosebeiTV bushes as weU as currant
bushes, apricot-trees, and plum-trees.

ACARI or Mites. Plant lice. — The acari
mucli resemble small minute spiders, diti'er-
ing, however, by their inarticulated body.
They are usually oviparous or ovon\aparous.
The larvae ditfer essentially from the adults
by their exterior conformation ; they want
principally a pair of legs ; they reach the
perfect state after several evolutions. Acari
l)roduce proliferations of the tissues : galls,
felting, swellings, brown rust, changes in
colour ; leaves become yeUow, red, or brown.
The most injurious acari are the Phytuptus
and the Tetranychus.

ACAROS OP THE GOOSEBERRY. Briobia
yL(6(',v.^Degeneration of the buds, leaves, and
shoots ; stunted and clustered.

AcARUs TEi.ARiDS, L. Red spider. — See
Tetranychus telarius ; French, Tetranyque
tisserand.

AcRiDiDES. Locusts. — Dangerous insects,
invading Algeria, Tunis, and even the South
of France. The best known are the Morocco
locust, the pilgrim or traveUiug locust, the
Italian locusts. See Locusts.

ACROSTALAGMCS ALBUS. — FuUgUS which

covers with a white thick down farmyard
dung fermented at too great a heat. It may
Ijecome injurious to young cultivated plants.

Adoxus titis. Kuniiilphu.f vitis, F.
French common names : Eumolplie, Gribonri,
Ecrivain, Berdin, Itiablntin, Vendangeur,
Bete a cafe. — Chrysomelide 5 millimetres in
length, elytron (wing shell), maroon red, cor-
selet and head, black. Insect as injurious to
the aerial part of the vine as to its roots.
The larvse hatch about mid-June and pass
the winter following in the subsoil where
they feed on the vine roots. In spring they
turn into grubs. The perfect insect hatches
in the month of April or May. It first at-
tacks the leaves, drawing straight and angu-
lar furrows ; then the grapes, on which it
makes grooves, which hinders the develop-
ment of the grape and prevents it from
ripening. The larva of the (jlribouri may kill
the stem, and the perfect insect seriously
damage the crop.

Aegekia tipoliformis. Sphinx tipuli-
I'iirinisj Tnirhili^im i ipuUfurmis. — The cur-
rant s])liyn.\ moth. See Sesia ajtifurmis.

(383)

Agaricus. — Mushroom.

Agrilus Sinuatds, Viridis or Piri.
French common names : Agrile du Poirier,
Bupreste Vert (green burn-cow). — Insect
1 centimetre long, "2 millimetres wide. Its
colour is copper green. Common insect,
which attacks a large number of forest and
fruit trees, chiefiy oak, beeches, and pear-
trees. The larva3 burrow in the wood and
bark, then towards the second year of its
evolution it pierces a hole in the wood, where
it becomes a grub. The insect hatches at
the end of June and lays its eggs in the bark
of the tree. The latter suffer much from
the invasion of the insect and produce no
more fruit. Trees invaded by the Agrilus
show cracks, often attributed to some other
cause, and which always cause the death of
the attacked branches. The young trees
almost infallibly perish.

Agriotes. Elaterides.— French, Mare-
chal ; English, wire-worms, click beetles,
skipjjing beetles, skipjacks, .spring beetles.
Small coleoptera of 1 centimetre at the most,
elongated and iiattened ; several species are
injurious to grain and other crops. All these
in.sects have the peculiar faculty of jumping
when laid on their back. The larvje alone
injure crops. They have a thin, elongated,
cylindrical body, like that of a worm ; then'
colour is yellowish, shining ; their maxi-
mum size is about 2 centimetres (f inch)
long ; their skin is scaly, very hard, and
difficult to crush, hence their name, wire-
worm, yellow-worm, under which name they
are generally known. Their development is
very long ; it lasts five years. They feed at
the expense of the roots and the tender
parts of the plant, and as they are very
voracious and polyphagous, they attack
almost aU cultivated plants, especially the
radicles of germinating corn-seed. They
sometimes cause considerable damage to
young seedling wheat brairding on a light
soil. During Aviuter the larvaj bury them-
selves deeply in the soil and there remain
benumbed, waiting for the renewal of vege-
tation. There are distinguished : (1) Elater
or Agriotes segetis, injurious to cereals ; (2)
Elater obscurus (the dusky click beetle),
injurious to carrots, cabbages, and salsify
(the purple goat's beard or oyster plant) ;
(3) Elater lineatu.'f, the striped click beetle,
injurious to cereals and hops ; (4) Elater
Sputatiir, Taiqjin craclwur, the spitting
click beetle ; (.5) Elater niger (Taupin velu)j
the black click beetle.

Agbomyza Viola.— The i)any-tly.

384 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Agrotis (Noctua).— The different species
injurious to crops have the same habits as
Agrotis segetum, the common dart moth.
Tlie caterpillars are polypliagous, make their
ravages at night and hibernate.

Agrotis Exclamationis. Xodua Ex-
cki Illation ifs. — -The hart and dart moth.
Dark lilac caterpillar, three bright longi-
tudinal lines, habits of grey-worm. The
caterpillar gnaws the neck of roots and
kitchen garden plants, turnips, asparagus ;
in spring it is particularly injurious to vines,
the buds of which it gnaws.

Agrotis segetum, the common dart moth.
— -The butterflies appear in the middle of May.
They lay in June, July, and August on all
low plants, chiefly beets, at the level of the
collar ; two weeks after laying they are
hatched. The grubs or grey- worm are typi-
cal : dark earthy green, two yellowish lines
on each ring, four small black spots, length 5
centimetres (2 inches). They make their de-
2}redatiuns in the night, and remain dose to
the ground during the day ; they pass the
winter in the ground where they bury them-
selves deeply like the white-worm ; they
awaken in the spring and recommence their
attacks up to May. This is the time they are
most to be dreaded. Winter grain crops, all
young spring plantings, and even the buds of
fruit trees sufl'er. They are especially in-
jurious to beets, of which they devour first
the young leaves of the collar then the collar
and the roots (1865 invasion). They also in-
jure potatoes and vines. They turn into
chrysalis in the beginning of summer.

Agrotis Tritici. JVortna of Wheat.—
See Agrotis segetvm. Similar caterpillar
also called grey-vonn. It appears in July at
the time the wheat plants are in ear and
devours them the whole summer. It not
only gnaws the collar of the stems but also
attacks the seeds. It passes the winter in
the soil and recommences its nocturnal de-
predations in the spring.

ALTERNARIA BRASSICiE F. NiGRESCENS.

Roasting (drilting) of the leaves of the
met on. — In tlic months of August and Sep-
tember when great heats are followed by rains
the leaves of the melon are seen to dry up
and brown. The fungus develops rapidly
on the leaves with small yellow spots ; as they
get larger these spots end in l}ig maroon spots
which cover the wliole leaf. The mycelium
spreads into the parenchyma of the leaf and
spreads its conidiophores on the faces of the
latter.

Alternarfa Soi.ani. MacrosjMirium So-
lan i (potato leaf-curl). — Peculiar disease of
the potato, characterized by the appearance
of isolated spots of a brown colour brighter
than those produced Vjy the I'hytoplithora
infeslAins ; the leaves turn yellow at the
same time. The tubers are not directly at-
tacked Vjut the exhaustion of the organs of
the plant may reduce the croj). The organs
of fructification are conidiophores which
issue in tufts through the dried epidermis
of the leaves. The detached spores germin-
ate easily and nvidily sjiread llie disease.

'Yhe, Alternaria fifolani which causes damage
more especially in Hungary is called Macro-
sporiuin Solani by the Americans.

Altises. llalticinece. Earth fleas, Plant
fleas. — Small chrysomelines which are called
earth fleas owing to their faculty of jumping.
In spite of their small size, which does not
exceed 3-6 millimetres in length, altises are
dangerous enemies to crops because they ap-
pear in great numbers. They have several
generations each year, the larvee of which, as
well as the perfect insects, ravage the leaves.
and the young buds. They are especially
deadly to young crops.

Altise (kitchen garden). Haltica oler-
acea, Alti.se of the Orurifers. — Length 4-5
millimetres, oval shape, slightly bomb shape ;
its colour is a brilliant bluish-green. This
altise attacks crucifers, cabbage, turnips,
beets, the flowers and leaves of which it
devours ; it causes great havoc in gardens.

Altise of the Vine. Haltim ampelo-
phaga (vine flea), Pucerotte, Babotte. — Small
greenish-blue insect, .5 millimetres. It only re-
quires six weeks to reach its full development.
It appears on the first fine weather. The
female lays its eggs at the end of April on the
under surface of the leaf, the larvae appear ten
days afterwards ; they burrow long grooves
into the parenchyma ; in ten days they reach
full size, let themselves drop on the soil and
there bury themselves to the depth of 2
inches ; two weeks afterwards the perfect
insects appear. The altises of the vine
cause great havoc especially in Algeria ; they
gnaw the back of the leaves and the vine
shoots. The last generation passes the winter-
protected from the cold under the bark, in
the fissures of the walls, etc., and issue from
these refuges in the spring.

Alocite. Sitotraga. cerealeUa. — Butterfly
(tinea) of 6 millimetres in length, greyish-
yellow, with long filiform antennae. The
Alucite has two generations in a .season, the-
first a little before harvest, the second in
autumn in the granaries. The female lays
red eggs in the depression of the grain of
wheat ; before harvest the caterpillars pene-
trate into the interior of the grain stored in
the granary where they finish their develop-
ment ; they gnaw the whole interior and
only respect the epidermis. After having
emptied the inside of tlie grain they tliere
weave a cocoon and are converted into rhry-
salis. The temperature of the heap of wheat
attacke<l increases 10° C. ( 180 F.°).

.\NBURY, see Plasmodiophora Brassic.k..

Angoii-1-UI.ide.k (eel-worms), .see Nema-

TODES.

Anohidm. XylopliagoKs coleoptera, which
cause rav.ages in our houses, and in food-
warehou.ses. They bore round holes into'
the wood which seem bored with a gindet.
The vrillettis have a cylindrical body, and
are of a diirk brown colour.

Anorium Panicdm, 2Ji millimetres in
length ; it does not live sofely in flour or in
bread ; it shows itself injurious to wood,
to books, to dried fruits, to roots, to grain.

Anthomvia of the Cahhace. . I nllioiiiyid

GLOSSAKY.

385

Bmssica' (turnip-fly. caliliage-fly). — ^ Length
7 millimetres, colour l)l;ii'kisli-i;TL'y, eyes red.
it flies in the mouth of May and lays its eggs
in the collar of the cruciferre. The maggot-
like larvffi penetrate to the interior of the
roots and the stems, there to hollow out
burrows, and in October are there trans-
formed into pupa to pass the winter.

Anthomyia op the Bdlb of the Onion.
Onion-Jiif. Three species: Anthdi/n/ic, an-
tiqun, A./nm(fii, A. a'piirvm. — -Small flies
of 7-8 millimetres, which lay their eggs end
of April and May on the leaves of the onion.
The small white larva descends along the
leaves, penetrates into the onion aild there
hollows out burrows ; it quits the onion to
become a grub in the soil. Tlie fly hatched
in fifteen days gives birth to a second genera-
tion. They are great destroyers of onion beds.

Anthonome of the Apple-Tree. ApiJle
blossom uverU, Anthonomi/s jiiiiiiiiruni. — -
Length. 4 millimetres ; colour, lilackish-
brown, with short, compact hairs forming a
down ; rostrum arched. The adult insect
lives the whole year at the expense of the
apple leaves. In the spring the female
pierces a hole in the floral envelopes and
deposits an egg in each flower bud until
finished laying thirty eggs at least. After
an incubation of five to eight days the larva
is hatched and attaches itself forthwith to
the stamens and pistils of the flower, thus
destroying the essential organs of the latter :
the bud henceforth expands no more, it
browns and dries up as if frostbitten. The
French gardeners call these browned buds
cloves.

Anthonome op the Cherry-Tree. An-
thonomus druparwn. — -Brown weevil of 5
millimetres which lays its eggs in the flower
buds of cherry-trees.

Anthonome op the Pear-Tree. An-
fhonmnns Pijri. — Weevil very similar to
anthonome of the apple-tree, but it lays its
eggs in the floral buds of the pear-tree before
and not during winter. Its larva is what
gardeners call the icinter-ivorui .

Anthracnosis op the Haricot. Col-
letotrichum. Liiidemuthiaiium. — Fungus
which attacks the leaves, stems, and pods
of the haricot ; it corrodes them profoundly,
producing gnawed spots very like those of
the anthracnosis of the vine. These spots,
sinking deeper and deeper, may extend into
the fruit as far as the endocarp of the pod,
and reach the grains. On the surface of the
spots there is formed a great number of
pustules, produced by the ctiticle, uplifted
by a mass of conidia. The mycelium of this
fungus does not pusli between the cells,
like the greater number of parasitic fungi,
but enters into the living cells, which soon
brown and die. Tiie spores, produced in
the pustules, readily germinate in water, and
the germinative tube, which issues immedi-
ately, ])ierces the epidermis to penetrate into
the leaf, producing a spot after twenty-four
hours. A warm temperature in moist weather
favours the growth of the fungus and the
extension of the disease.

Anthhacnosis of the Melon. Colletn-
triclniiii ii/i(/(H'/iu'/inii (Fr. .\ nil c dii, Melon).
— The anthracno.sis of tlie melon is observed
on dirt'erent cucurbitaceie. When tlie very
young plants are attacked, they are rapidly
destroyed. Adult plants resist better and
longer ; but the fruits attacked, as well as
the leaves, are entirely nlisorganized before
reaching maturity. The disease is char-
acterized by badly defined, yellowish spots
which go deep down, especiallv in the fruit.
The fructifications of the fungus apjtear on
the dead tissues. They are small fleshy-rose
masses containing conidia.

Anthracnosis op the Vine (grape rot).
Gloeospuriuiji iijiipehiph«iviin, syn. Sphacc-
hniia aiiipcloplKiijd , ('arbonnat. — The fila-
ments of this fungus only live in--ide the cells
and produce spots on all the herbaceous parts
of the vine, each forming small ulcers
gnawing the tissue as far as the soft parts of
the liber. The branches are contorted and
blackened as if they had been roasted on
the fire.

Aphis (singular). Aphides (plural). Xaknl
plant lice.- — In spite of their small size, the
aphides do as much damage as large insects.
They live in colonies, of which the individuals
—always numerous — tightly packed the one
against the other, reproduce themselves in-
creasingly during fine summer weather and
give birth to a progeny of thousands. Far
from circulating from leaf to leaf, these ap-
terous insects remain, on the contrary, fixed
on the same spot ; their rostrum, planted in
the most delicate part of the plant, continu-
ally sucks the abundant juice which flows
thereto. The result of this constant irritation
of the cells of the plant is that it dies, or is
in a diseased state, which shows itself by char-
acteristic deformation of the organs. It will
be seen that the leaves and the branches curl
up, roll, swell, change colour, passing through,
white to yellow to red. Often exostoses and
cankers are formed which gi'eatly injure the
physiological functions of the organs and
render the plant diseased. Moreover, the
plant lice secrete from their cornicles (small
horns) a sort of honey-dew which they eject
afar and which ends by covering the whole
trees with a sticky, sugary layer preventing-
the respiration of the plant and attracting
insects fond of this sugar. Fungi of the-
family of Capnodium, which live exclusively
on this waste, develop there and ttnally
cover the entire plant with their black
mycelium, thus causing a disease known
as Fumagine or smut of fruit trees. In the
spring almost at the same time as the young
buds the female aptera appear generally
viviparous which are reproduced by par-
thenogenesis, that is to say, without the aid
of the male. The young, always of the
feminine sex, resemble them, and are capable
of reproducing themselves in the same way
in a few days. Parthenogenic repro<luction
of these individuals goes on during the
whole of the tine suimuer weather, and the
more rapidly the drier and warmer the
weather. When the weather cools in the^

25

386 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

autumn tbe last generation of these plant
lice no longer produce viviparous individuals
the same as themselves. They then lay
eggs from wliich issue a short time after-
wards either males or winged females which
copulate. These females lay eggs in their
turn. Amongst these es;gs some give birth
to apterous viviparous females which wait,
hidden in the moss of the trunk, the heat
of the spring to reproduce themselves and
so recommence the cycle described. Tlie
others hibernate, hidden in the fissures of
the bark and are not hatched until spring.
Plant lice have not therefore like other in-
sects slow and complicated metamorphoses
which limit the number of annual generations,
but although compelled to go through a
.special cycle the females are capable of
reproducing themselves indefinitely into
simUar individuals without aid of the male
and without slow evolution. That enables
them to create in a season a legion of in-
dividuals endowed with the same destructive
capacity and the sum of the work of which
often produces terrible effects on the plant
invaded. The number of species is unlimited,
and there is no plant which does not possess
one or more species which produce a char-
acteristic degeneration of the organs attacked.
The spitting Ai'Hrophora. Aphrophora
Spumarla. Heiiiiptera, of the grasshopper
family, which lays its eggs in the end of
autumn in the bark of plants. The larvag,
which hatch in the spring, suck the juice of
plants and surround themselves so as to pro-
tect themselves with a viscous matter con-
i^isting of air-bells, resembling saliva so much
as to be mistaken for it. Where they occur
in very great numbers they may become in-
jurious.

ABMiLL.\KiAMELLEA(tree-rootrot).— This
fungus lives as a saprophyte and as a parasite ;
its mycelium penetrates into the living roots
of very difi'erent species of trees and develops
in the hark and in the exterior layers of
wood ; from the roots it gains the foot of the
tree and there it produces yellowish-brown
clusters of receptacles on the level of the
ground. It attacks vines, apple-trees, mul-
berry-trees, fig-trees, on which it causes
diseases whicli are confused with others
under the general name of rot. [Common-
est and most widely distril)uted of British
toad-stools.]

AT(fAi,i.\ si'iXARUM (turnip saw-fly), see
Tenthkedo.

Athous. -Elaterides, the larvfe of which
injure crops, see Aghiotes.

Athous ii.KMoiiitHoiDALis, Injurious to
the gi-owth of flowers.

Athou.s HiiiTUs, injurious to beets.
Athou.s NioEit, the black click beetle, in-
jurious to potatoes.

Ato.maiua f.mEAHls. — Coleojitera, 1 milli-
metri! in length, with finely dotted elytra.
'The jjerfect insect appears at the moment of
the germination of beet seed. It attacks the
suljtorranean ])ortiou of the seedling and de-
stroys it. If the plant Ls in liraird the in-
.sect pierces .small holes near the collar ; the

young beet blackens and dies. If it survives
the root becomes forked and its sugar content
is lowered. The insect afterwards attacks
the leaves. The damage is done from May
to July.

Black Rot of the Grape. Guignardia
Bidwelli. — This disease, reported in France
for the first time in 1885, is of American
importation. It causes frightful ravages
because it invades and destroys the grapes.
It is due to the parasitism of a Sphseriaeeae
which in succession shows conidia fruit and
asci fruit. On the stalks of the leaves
black rot shows itself by reddish, more or
less circiilar, well-defined spots. These spots,
small at first, become larger and finally run
into large black spots consisting of conidia
fruits. These same spots "are formed on the
branches on the cluster of grapes and on the
grapes themselves. The black rot appears
about mid-July when the grapes are as big
as peas ; it first forms a livid spot which en-
larges quickly and invades the whole pulp ;
the grape then fades, its surface is depressed,
forming large folds and it dries rapidly, as-
suming a violet-black colour. During this
time there is formed on the black wrinkled
surface of the gi-ape thousands of small black
globular projecting granulations which are
the conidia fruits of the fungus called
pycnides. It is not until winter that the
peritheca, globular conceptacles filled with
asci, are formed in the midst of the tissues
of the dried grape. Up to the month of
June of the following year these peritheca
are found filled with well-developed asci
on the grapes which have passed the winter
either on the stock or on the soil. The
ascospores germinate in a few hours after
having been projected out of the asci.
They put forth a germination tube which
penetrates the epidermis of the leaves and
thei'e produce the spots described above.
The organs of reproduction of black rot are
of three kinds : the first and the second are
conidia fruits which appear in summer on
the leaves and the fruits and give out spores
which spread the disease during the year ;
the third consists of peritheca, the spores of
which transmit the disease to vines from one
year to anotlier. A knowledge of the succes-
sive phases of this disease alone enables it to
be overcome ert'ectively.

BoMBYciDES. — Nocturnal moths, heavy
and squat in shape, with a body abund-
antly covered with hair ; the wings are at
rest, sloped like a roof. The males have
three pectinated antenna'; they are smaller
aud darker in colour than the females. The
caterpillars almost always bri.stle with numer-
ous long hairs ; they spin cocoons to trans-
form themselves into chry.salides.

BOMBYX ANTIQIIA, 0R(!YA ANTIQDA (the

conunon vai)i)urer or brown tu.ssoi^k). —
Sexual diniorphisiM ; female grey, apterous;
male reddish-brown, two white spots on the
upijer wings ; the butterfly appears in June.
The caterpillars are especially fond of pear-
trees. Several generations uji to October.
BoMHYX Chry.sorrhea Moth. Liparis

GLOSSARY,

387

chrysorrhea (hrown-tailel moth).— ButterHy,
30 millimetres (1'2 inch) troiu tip to tip.
Wings white, as also the whole body, except
the posterior extremity of the abdomen,
which is brown. Tiie female lavs its eggs
on t'le upper surface of the leaves, or on the
branches of the trees, in agglomerated heaps
covered with the brown hairs of the ab-
domen of the female, whijh gives them the
appearance of minute sponges. The eggs
hatch t^wanls the end of summer ; in autumn
the caterpillars spin a common nest on a
liranch and there pass the winter dormant.
In the spring they issue ivim this refuge,
and comm;ince their serious depradations by
eating the young buds. Thev are brown
with two red dorsal stripes and two white
lateral spots. Injurious to fruit trees.

BOMBYX DISP.\R, LiPARIS DISPAU, OC-

NERIA m.sp.\.R (gipsy moth). — ^Great differ-
ence between the two s^xes — the male has
greyish-brown wings 3 centimetres, the
female has yellowish-white wings 5 centi-
metres ; the two are marked by zigzag lines.
The female lays 500 eggs a'ld covers them
with a felt formed from the long brown
hairs of its abdomen, the whole resembling a
.small sponge. The eggs pass the winter,
the caterpillars hatch in the beginning of
May ; they are blackish with blue and red
tubers ; they live together, are polyphagous,
and attai'h themselves, therefore, to a gi'eat
number of trees — -forest trees as well as fruit
trees. In the United States they form a
real plague. Bombyx dispar was introduced
into America by a collector, where, deprived
of its parasites and its natural enemies
which decimate it in Europe, it has multi-
plied in such a disquieting fashion that a
prize of 25,000 dollars was instituted to
recompense whoever found an efficient remedy
to cause its destruction.

Bombyx mox.vca, Liparis moxaca (black
arch moth). — Resembles the Bombyx dispar.
The female lays its eggs at the end of July
in small heaps of 20-50, forming plates which
are never covered with hair. They are hidden
in the cracks of the ba";k near the ground,
they pass the winter. Hatching occurs at
the end of April ; the caterpillars remain
together five to six days forming what are
called mirrors ; they gnaw pine needles.
They cause great depreilations in pine woods,
they also attack the spruce, the oak, the
beech, the apple-tree. Its invasions some-
times become a public danger.

Bombyx xeustrea (the lackey or barred
tree lackey moth). — -ButterHy of 30 milli-
metres from tip to tip ; reddish, tlie upper
wings are crossed by two whitish lines. It
appears in July ; the female lays regularly
around a branch, and, by help of a fixing,
coat 400 eggs which form a bracelet.
These egas pass the winter ; the caterpillars
live together in spun nests. When adult
they are 4^ centimetres in length, a brown
with a white dorsal stripe down the middle,.
and on each side red and blue loiigituiUnal
lines, hence its French name of livrre. In-
jurious to almost all trees.

Bombyx pini, Lasiocampa pini (pine-tree
lappet moth). — Butterfly from 5-t) centi-
nietres from tip to tip, maroon colour. On
the upper wings a large dun-coloured middle
band and a small spot in the form of a half
moon. It shows itself in July. The female
lays on the trunks of the J'inus .si/lvestris
(Scots fir) in masses of 50 eggs which hatch
about the middle of August. In the be-
ginning of wintL^r, in October or December,
the caterpillars descend the trees to pass the
winter dormant under the moss and the
dead leaves. In the spring, in March or
April, they re-ascend and attack the young
shoots, frequently causing the death of the
trees. Invasion in 1894 of the phie woods of
the departments of Marne and Aube.

Bombyx processionea, Cnethocampa
PROCESSIONEA.— Butterfly of 3 centimetres,
greyish, uniform with dark sinuous bands
on the wings ; it flies in August and Sep-
tember, lays its eggs in packets of 200 on
the bark of oaks and covers them with hair ;
the eggs pass the winter. The caterpillars
pass all their existence together ; they are
bluish-grey withreddisli tubers whence tufts
of hair spring. The nests in which they
shelter each night have only one orifice.

BosTRiCHUs [Borers].— Small coleoptera
belonging to the family of the Scolytides,
distinguished by their cylindrical and bomb-
shap9(l body, by their thick head drawn back
into the thorax. They prefer to attack sickly
trees, piercing the Ijark, then digging into its
thickness a burrow in which the females lay
their eggs ; in six days the eggs are hatched";
the larvEe dig winding burrows perpendicular
to the chief burrow. The caterpillars are
metamorphosed there. The insects perforate
the bark and fly away.

BosTRicHUS TYPOGRAPHicus. — The typo-
grapher bark beetle. It only attacks spmce
trees ; its presence is indicated by pale foliage
of a dull tint, by a dark grey bark, by the
fall of the needles at the least shake, and bv
a worm mould of havanna brown, after the
asperities of the bark.

BoTRYTis CINKREA (grey rot of the vine).
Vine Sderafiiiia, Sderotima Furkeliuna, De
Bary. — In a humid and warm medium this
fungus, generally saphrophytic, attaches it-
self ti the leaves and the young buds of the
vine ; the young bunches of grapes may, like-
wise, l)e invadeii at the time of flowering ; but
it is chiefly when the grapes are half-grown
that the pa deed and compact grapes are at-
tacked and destroyed by this fungus. The
grapes attacked fir.st assume a dirty tint, their
surface tarnishes, tliey wither and become
covered with a velvety grey which character-
izes this disease. The favourable eflfect exer-
cised by this mould on the quality of the
white wines of Sauterne earned for it the
name of Punrriture nobh: (noble rot), but
this rot threatens to l)ecome a real plague
since it invaded numerous vineyards and
destroyed the crop. When the Botrytis
develops only on ripe grapes it causes no
damage, it is only then that it improves the
quality of the wort. The green mould does

388 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

not attack the vine alone. On a number of
plants on wliicli at the outset the stems are
seen to become brown, fade, and wither
\\dthout apparent cause, the medulla con-
tains Sclerots which produce couidiophores
of Botrytis covering the damaged organs
with an ashy, velvety grey. In gardens the
lily, digitalis, balsam, the gi-eater gentian,
rose bush, the pelargonium, the liegonia, the
quarantine clove, hemp, may be mentioned.

Browning of the Vine. Plasmodio-
jjhora. — Damage to the leaves of the vine
which occurs in autumn. Brown, irregular
spots are seen to form on tlie upper surface
of the leaves which extend in such a way as
to form large sheets, sometimes completely
covering the greater part of the surface of
the leaf. This disease is attributed to a
fungus, the l'lasiiiii(/iiijjl/iira vitis.

Browning of the Le.wes of the Pear-
Tree and Apple-Tree. PhyUocoptes Sch-
lechtendalL — The acarus which produces this
browning lives freely on the surface of the
leaf ; it neither produces galls nor felting.
Its bites cause small isolated spots in the
beginning, but which increase and brown
afterwards.

Bruchus. — Small, squat-shaped weevils
which attack the different leguminous seeds,
peas, lentils, beans, tares, haricots. Each of
these is attacked by a special species of
Bruchus, but always in the same way. The
perfect insect lays its eggs in the spring in
the pods as they are being formed. The
larvae penetrate into the seed ; there is gener-
ally only one larva per seed except in beans
and haricots, where there may be two. The
seed develops in the usual way, for the larva
gnaws the albumen whilst respecting the
grain. The larve reaches its development in
the end of winter ; it is transformeil into a
grub in the hollow seed, and in the month of
May the perfect insect issues from it by
boring through it. These seeds have lost a
great part of their weight. If utilized for
seed they have the drawback of sprhiging up
badly and yieliliiig weak i)lauts. The seeds
attacked are easily known by their light
weight, for they float in water, or by the
small opening through which the insect has
made its exit.

Bdnt or Stinking Smut of Wheat.
TUhtiii fJaricK.' — Fungus analogous to Usti-
luijo (smut) which only attacks wheat grain.
At harvest time the grains which do not,
however, show any distinct outside indica-
tion, arc lillcil Willi a brown ]jowder which
exhal(;s a. foetid odour. Tliis ilust consists
of s|K)res. 'V\u: spores germinate in a moist
medium and the germination filament pierces
the stem of tlie wheat at thc^ moment it starts
to grow. See under Ustii.ago, p. 406.

Calandria granaria (wh(^at weevil).—
Black coleoptera 3-4 millimetres long, the
head is prolonged by a lengthy rostrum.
The calandria passes tlie winter in the de-
pr(!Ssions of the lloor ; in the spring, in Ajjril,
it gets into the heap of wheat, ])ierces a small
hole in the groov(^ of the grain and there lays
a single egg. The same weevil thus pierces a

large number of grains until it has ceased
laying. The larva gnaws the interior of
the grain ; it only leaves the exterior pellicle
which it uses as a cocoon to protect its grub.
Hatching occurs in forty to fifty days.
Breeding goes on all the fine summer weather ;
a single female may have a progeny of 60,000
insects in a season.

Capnodium, see Fiimagine.

Capricorn (small) : Cerambyx cerdo. —
Coleoptera 2 centimetres long ; attacks oak
and fruit trees, chiefly cherry-trees and apple-
trees in the same way as the preceding.

Capricorn : Cerambyx heros (the gi-eat
Capricorn). — Black coleoptera 5 centimetres
Ions; with two long antennse which in the
male are longer in the body. Corselet
rugose. The larvje which are very large
attack the oak preferably ; they take three
years to become perfect insects and cause the
death of the finest trees by the numerous
and wide burrows which they bore in the
trunk.

Cassida NEBCLOSA. — Coleoptei-a (chryso-
raelide) 1 centimetre long, oval, with lateral
expansions of the corselet and elytra forming
a carapace recalling that of the tortoise. The
perfect insects hibernate and issue from their
retreats in the spring. The females lay their
eggs on the upper surface of the leaves of
the beet. The larvaa, of a pale green colour
with two longitudinal white stripes, attain 1
centimetre in length. Segregated in great
numbers on the under side of the leaf in the
beginning of plant growth, they cause con-
si(lei-able retardation in the growth of the
beets. There are as many as three genera-
tions a year.

Cassida viridis, or the artichoke tortoise
beetle, is found in May and June on artichokes
not more than jV of an inch in length. The
antenn;e are black, the dotted wing cases
and other outer coverings green, the body
black, beneath legs pale, thighs black, body
of larva very flat.

CEciDOMYiE. — Small gnat-like flies, 2-S
metres long, with long slim legs. The most
injurious are : —

Cecidomya destructor (Hessian fly).—
Blackish with red circles on the abdomen.
It appears in April. The larvre attack the
base of the stem of wheat without penetrat-
ing into the interior ; by persistent sucking
they end in making small pits in the stem in
which they lodge. Atrophy of the stem of
the wheat results, and the latter soon l)reak.s.
There are three to four generations ; the last
generations are especially dangerous because
the larvfe attack the plants and destroy them
to a great extent.

Cemio.stoma scitella (black spots of the
leaf of the pear). — Microlepido])tera, the
caterpillar of which is minute, which is to say
that it gnaws liurrows between the two epi-
dermes of tlu- leaves of the pear. These
spots beconu' black.

Cercospora apii (celery leaf blight). —
The celery as well as other umbelliferte,
such as ])arsley and parsnip, are attacked
by this fungus, especially during the hot

GLOSSARY.

389

part of tlie year. The leaves are coloured
with t'awu-yellow spots, and when the fructi-
fications appear tliey are covered with a
brown dust. The spores soou germinate
and invade the neigliliouring and new leaves.
Their germination tube penetrates into the
parenchyuui of the leaf, there ramifies and
produces an alteration of tlie leaves which
deprives the celery of all its market value.

Cercospora beticol.e (spots of the
leaves of the beet).— This fungus is a very
commou parasite which lives on the leaves
of the beet, but which causes no special
damage ; in wet seasons it propagates very
rapidly, and the leaves are covered with grey
spots bordered with brown from which the
conidiophores issue in tufts, the conidia of
which soon germinate.

Cercospora reseda (mignonette disease).
— This fungus forms pale spots on the leaves
of mignonette, which afterwards are covered
with Tjrown tufts of conidiophores. It causes
much damage in America.

CetonI/E. — -Coleoptera, some of which are
gilded, 1-2 centimetres in length, the larva? of
which live in dung. The adult insect passes
its life on Howers of which it devours the
pistil and the stamens. They may become
injurious to fruit trees, especially the Cetonia
stictica and tlie velvety cetoin, Cetonia hir-
telhi. on the vine. [Ci'tonia (iv.rat(i, the green
rose-chafer or golden rose beetle, is one of the
largest an<J. most beautiful beetles. The
havoc they make in the Parisian rose gardens
is said by C. Mcintosh to be fearful compared
to what we experience in Britain (Tr.).]

Cheimatobia bru.mata (winter motli,
Evesham moth). — -ButterHy, only the male of
which possesses wings whilst the female has
only rudimentary wings and cannot tly.
The female, hatched towards the end of
Octol)er or the beginning of November,
crawls on the tree with its large legs to
lay its eggs in the crannies of the bark.
The caterpillars -hatch in the beginning of ■
spring. They keep to the buds of fruit
trees and gnaw the leaves and the flowers
as they shoot out.

Cherry-fly. — -This fly, 4 millimetres long,
is lirilliant black witli a heaii and legs yellow
anrl the wings crossed by four black bands ;
it appears at the end of May. The female lays
a single egg on each cherry, preferal^ly on the
bigarrecm and the geans. Tlie larva pene-
trates into the interior and renders the cherry
wormy. In the end of July it quits the
cherries and lets itself fall on tiie ground
where it is transformed into pujja, a sort of
small barrel with a hardened skin. The in-
sect issues in the following spring.

CiCADBLL.E (grasshoppers). — The Cica-
<lellre are small jumjjing grasshoppers which
are sometimes injurious to crops.

CiCADEI.LA SEXNOTATA, JaSSOS SEXNO-

TATUS (Cicadella of oats, Cicadella of cereals).
— Yellow grassho]jix'r, with brown spots, .3
millimetres long. They suck the leaves of
the oats wliich turn yellow and wither.
This small grasshopper causes Vjy its numbers
great havoc in young fields of corn, chiefly in

oats and barley fields. These insects pro-
duce two generations in a year. Those of
the second generation pass the winter in the
shelter of the clods of earth. The grass-
hoppers only attack young plants, the leaves
of which they suck. In the spring they
choose winter wheat. As soon as the leaves
become too hard they quit them to (levastate
the spring seedlings. The plants attacked
are known at first by their red and then
yellow tint ; they soon perish.

Cladosporium carpophilum (plum scab).
— It causes damage in America. It attacks
the young fruits, producing spots, on which
the skin is replaced by a sheet of cork under-
neath which hollows are formed ; attacks
plums, cherries, almonds. — Tr.].

Cladosporidm cucdmerinum (cucumber
rot).^This fungus produces on cucumbers
black-greenish spots and the rapid rotting of
the fruit.

Cladosporium fulvum (tomato leaf rust).
— The cladosporium causes great damage
to tomatoes, especially in greenhouses. The
leaves of the stocks attacked etiolate, turn
yellow on bailly defined portions of the limb,
attain a length of 1 or more centimetiKS.
On the parts of the leaf which are quite
yellow above, a greyish olive coating is found
underneath formed by the conidiophores of
the fungi. The detached conidia spread the
disease.

Cladosporium oleaginum (spots of the
leaves of the olive-tree). — The smooth myce-
lium glides under the superficial layer of
cuticle and becomes encrusted in the upper
cell walls of the epidermis ; it does not pene-
trate into the parenchyma of the leaf ; in this
connexion it has a certain analogy with ex-
oascus. At a given moment the mycelium
pierces the cuticle, swells above the epidermis
into a lump which produces spores at the
summit. The spores attack the new leaves
and there produce circular greyish or yellow-
ish spots encircled with black.

Clematis Disease, Black.— Disease due
to parasitism of an anguillulide, " eel-worm,"
of the genus Heterodore which causes galls
by its pricks on the roots of the clematis.
CocniDES or Cochineals (plant lice,
bark lice, scale insects, kermes). — -These hom-
optera much resemble the " pucerons " by
their manner of living. After hatching, these
insects show great agility ; then the apterous
females fix themselves either on the young
shoots, the leaves, or the trunks, sink their
rostrum in the tissues and never move again.
The body is ovoid, globular, and resembles a
small excrescence of the bark. The female
lays its eggs under this shell and dies, form-
ing with its carapace a protecting shelter for
its progeny. Tlie plants attacked by these
insects perish rapidly and are often invaded
by " fumagine," or smut of fruit trees (Cap-
noilium), the existence of whicli is intimately
linked with the presence of these insects.
Like the pucerons, the cochineals become
dangerous by their number ; they entirely
cover the bark of the trees. Tlie cochineals
pass the winter dormant on the branches.

390 INSECTICIDE?, FUNGICIDES, AND WEED KILLERS.

These are distinguished by tlie shape of the
shield, the diaspiues with the genera As-
pidiotus and diaspis, the lecauium, the coc-
cines. The most common are the following : —

Cochineal of the A^yple [Alussel scale)
(Mf/tilaspis pomorum), (? As2ndiotus con-
chili form). — The shield resembles a small
mussel shell. It attacks apple-trees.

Cochineal of the ]'c(ivh {Li'i'aniuni Per-
siccb). — Very frequent on peaches in May and
June.

Cochineal of the Pear-Tree (Aspicliotus
ostreaformis), (the pear-tree oyster scale).
— One of the most common of cochineals,
distributed on the branches of fruit trees,
especially apple-trees, where it forms small
greyish spots.

Cochineal of the Pear-Tree [Diaspis piri-
cola). — -Analogue of the cochineal of the
apple-tree ; the cochineal of the pear-tree has
a red colour and not yellow like that of the
apple-tree, a colour which is discerned by
lifting the shield with the Ijlade of a knife.

Cochineal of San Jose (San Jose louse),
(Aspidiotus perniciosus). — It much re-
sembles the preceding, and exercises its
ravages, especially in America, on both fruit
and forest trees.

Cochineal, White, of the Lemon-Tree
and Oranne-Tree (Dacti/lopiiis citri). — -Its
brown body is envelopeil in a white waxy
secretion ; the trees attackeil look as if covered
with cotton. The saccharine dejection, the
honeydew, covers the leaves with a waxy
secretion on which a Capnodium develops in
abundance, creating the grave disease of the
fumagine or the black of the olive. The
trees invaded lose their leaves, perish, and the
fructification cannot generally take place.

Cochineal, Red, (f the Vine (Coccus Vitus
or Pn.lrinaria Vitus). — The red cochineal
of the vine has the appearance of a reddish-
brown shell ; at the time of laying, it secrets
a whitish cottony substance which forms
above tlie body a sort of cushion very ap-
parent. The males (coques) are 5 millimetres
in length and are found along the branches.
In the beginning of autumn the females
fix themselves on the branches and assume
the form of a shield.

Cochineal, White, of the Vine [Dacty-
lojnus Vitus). — The white cochineal of the
vine, contrary to the red cochineal of the
vine, never fixes itself and lays its eggs
several times. The female is 4 millimetres
long, the body shows distini't segmentation.
These cochineals appear in the month of
May. They lay their eggs in June on the
under surface of the leaf. The adults pass
the winter under the bark of the stems or in
the soil. They cause tlie fumagine or smut
of fruit trees.

CocKCHAKKRS (white-worms). French,
l]annel(ins, Turcs, J/r/,/(.v.— Lainellicorn cole-
optera, the larva; of wlucli, the wire-worms,
are polyphagous. The common co('kchafer,
Mki.OLONTHA V0riGAUIS. French, Hanneton
coniinun. The female lays thirty to fifty

eggs in the soil, at a depth of 3-7 centimetres.
The larvae hatch forty days after laying, their
development lasts three to four years, accord-
ing to circumstanrt-s. In November each
year the white-worms sink into the soil to a.
depth varying from 50 centimetres to 1 metre,
according to their size and the Sc^verity of the
winter. They there remain dormant during'
winter ; five mouths afterwards they re-as-
cend near the surface and gnaw the roots of
plants. They cause great damage in vine-
yards, meadows, beet-fields, and gardens.
Having finished their growtii in the month
of August, the white-worms nymphose at a,
depth of 1 metre (40 inches) iu the soil
where they are surrounded by a shell. In
November the perfect insect is given off by
the nymph, but it remains in the soil to the
spring, that is to say, until the beginning of
the fourth year from the laying of the egg.
It takes one or two months to reach the sur-
face of the soD. White-worm years result
from this triennial cycle of tlie evolution of
the white-worm. The evolution lasts three
years in the south of France, four years in
the north of France. The larvaj are poly-
phagous, that is, gnaw indiscriminately the
roots of all cultivated plants. Recently
planted vines are frequently invaded, they
cease to grow and their leaves turn yellow ;
the proportion of destroyed grafts may reach
94 per cent.

Cockchafer (Grain). Rhizotrogus sol-
stitialis. Hanneton de la St. Jean. — The
larva is injurious to cereals, maize, trefoil.

Cockchafer, Green (Pine). Melolontha
fullo, L. Hanneton foulon. — -The larva of
this big butterfly is injurious to pines.

Colaspidema ater (French names : Col-
aspe, Negril, Babotte noire, Jiarhare). —
Black lustrous, 3 millimetres long. The
colaspidema is a plague of the lucerne fields
of the south of France. In the mouth of
May the female lays about 400 eggs on the
lucerne leaves where they hatch in twelve
days. The larvse are so voracious that a
lucerne field may be ravaged in a few days.
The perfect insect passes the winter under-
ground, the larvfE is converted into a grub
in the soil ; it hatches in the spring.

Conch VLis ambignella (cochylis of the
vine, the vine tortrix). — This small tortrix
is about half the size of the pyralis of the
vine, its length is 8 millimetres. The upper
wings are yellowed, crossed by a wide brown
band. The under wings are grey. Two gen-
erations annually. Tlie caterpillars of the
first generation invade in May the young vine
shoots of tlie vine in Hower, of wliich they eat
all the i)arts ; the vine shoots which escape in
the spring are after vvards attacked by the
caterpillar of the second generation which in-
vade the shoots at tlie time the gra])e ri})ens.
When they have linislicd their work of de-
struction these grulis take refuge towards
the montiis of September under tlie barks of
the stocks or on the fissures of the pi'ops.
There they assume the chrysalis form after
spinning a silky cot^oon.

Cossus L1(;nii'EUDa (('oss)(s ijate hois.

GLOSSARY,

391

goat moth). — This bombyx lives three to five
years as a firub which attacks indifferently
weeping willows, poplars, elms, fruit trees,
larches, and many other trees ; it bores holes
into these trees of the thickness of a linger
which in multiplying form immense cavities
on the trunk. The caterpillar is naked,
bright red in colour ; it gives off a decided
odour of musk.

Crioceris asparagi (asparagus beetle).
— Coleoptera (chrysomeliile) of 6 millimetres
iu length, steel blue elytra, with four bright
yellow spots.

Crioceris DUODEciMPONCTATaM. — Red-
dish-yellow coleoptera with six black points
on each elytrum. These crioceres appear iu
the month of May. Their green viscous larvse
attack the asparagus, the leaves of whicli
they gnaw. In June they btiry themselves
in the soil where they hibernate iu a small
sheU.

Crioceris melanopa (grain crioceris). —
This small (4i millimetres) coleoptera is
bluish ; it and also its larvae gnaw the epi-
dermis of herbs and cereals.

Cdrculionides (weevils). — • Coleoptera
characterized by a prolongation of the in-
terior part of the head called the beak or
rostrum ; the form of the body is bomb-
sliaped, for the elytra always surround the
lower part of the abdomen. The larvae are
polyphagous, they live in the interior of the
vegetable tissues (fruits, roots, stems, buds,
seeds).

Carrot Weevil (Moli/tes Coronatus). —
Brilliant black with some yellowisli spots,
12 miUimetres long. In May the eggs are
laid in the soil, the larvae penetrate into the
lower part of the carrot and ascend it by
excavating burrows.

Ceutorhynchus snlcicolUs (cabbage and
turnip gall weevil). — Black, 3 millimetres
long, appears in May, attacks all crucifers,
cabbage, rape, colza, turnips, mustard, etc.
The female lays its eggs in July in the roots
or the lower part of the stem. The larvae
attack the bark. The irritation produces a
hypertrophy of the parenchyma, generates
nodular galls which grow until the larvae
perforate them, to turn into grubs in the
soil. This insect is not dangerous except
when it develops in ^•e^y large numbers.

Curci-dio (Olinrhi/nchus) Liijustici. In
French Beccard (female salmon). — This
large brown weevil attacks fruit trees at
night, also cultivated crops such as Vetches
and Siilnfdiii. The female lays its eggs in
the ground. The larvaj hatch in the middle
of summer and gnaw the roots until the
following spring, when they are metamor-
phosed to perfect insects about the end of
May.

Curculln (Otlnrhynclms) sulcatum (grooved
weevil otiorhynchus, vine black). — This
small weevil attacks the vine, the straw-
berry plant, and various ornamental plants.
It is chiefly rcpn'ted from Bordeau.v, Lan-
guedoc, and Burgundy. It appears about
the end of May in vineyards and browses

on the Inids and young shoots during the
niglit. Its larviB live underground at the
expense of the roots.

C'urcidiu ( Phytonoinus) pnnctatus. — The
larvae riddle the leaves of trefoil and lucerne.

CurcnUo (Sifini''.^) Vin 'U' k .■< (striped pea
weevil). — Injures leguminos;T', esjiecially peas
aud haricots. Tlie perfe:;t iusi- •!, gnaws tlie
young leaves in tlie spring, the larv;e gnaw
the roots.

CoRRANT Leaf Spot, see Guesporid.u

RlBIS.

Cdrrant Saw-fly (Nematus Ribis).

Cl'scuta epithymum (dodder of trefoil
and lucerne). — These plants which are de-
prived of roots and of chlorophyll are essenti-
ally parasites of other plants from which
they draw nourishment by numerous suckers.
The latter are formed at all points where the
stem, enrolled as a tight spiral around the
nurse plant, touches the surface of t!ie latter.
They extend rapiilly in fields where the ex-
hausted anil dead plants form large spots.
The rose-white flowers form seeds from which
issue the young plants which crawl before
fixing themselves and are even conveyed by
the wind to a great distance.

Dasyscypha Wilkommi (canker of the-
bark of the larch). — The canker of the bark
of the larch often causes very great ravages.
The first symptom is manifested by a yellow
tint which the branches assume, the leaves
fade and there is almost always a flow of
[oleo] resin which is produced at a point
where the bark is swollen aud broken. On
the dead aud drier! bark appear small white
spots which, when the conditions favour their
growth, develop into small cupules of pezize,,
white velvety outside and bright red on the
upper surface. The mycelium of tlie fungus
penetrates through the medullary rays and
the resiniferous vessels.

Dematophora necatrix (white root rot).
French names: Blanc des racines, Morta-
duse, Terre-bete, (rvappe, Morille, Charme^
Pourridie de la T'/grwe.— This fungus lives at
the expense 'of the roots of the vine, fruit-
trees, mulberry-trees, fig-trees, maple-trees,
oak-trees,aud soon kills the tree. Its mycelium
forms round the roots a white cotton-wool
which afterwards assumes a greyish tint. It
penetrates deeply into all the anatomical
elements of the root, and it is only when the
plant is dead that it produces fructifications.
The white root rot is especially attributed
to the Sphceriace.ee Dematophora, but this-
fungus is not the only one capable of pro-
ducing this physiological condition of fruit
trees. There are also A rm illaria mellea (q.v. )
aud Rnesleriu hypogea,o{ which the mycelium
invades the roots of trees in an analogous^
manner and causes the rot of the latter. A
vine attacked by this fungus languishes-
rapidly and finally dies.

DOTHICHIZA POPLTLEA.— This fungus pene-
trates into the wood of the poplar through
wounds and kills the parts invaded.

Dry Rot, see Meruijus lacrymaxs.

EucHLORA vrns (Anninala ritis, green.

392 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

cockchafer of the vine). — -The female of this
coleoptera lays about thirty eggs iu the soil
roiiud the stem ; the larvse appear in the be-
ginning of the mouth of August. They
much resemble those of the cockchafer ami
do the same damage to the vines as the cock-
chafer (white-worm), ( Ver blaiic).

Entomoscelis adoxidis. — The perfect in-
sect and its larvie guaw the leaves of radishes
and cabbages in Canada.

Epilachxa globosa. Cdccinella glohnsn.
— -The larviie of this coleoptera riddles the
leaves of trefoil, lucerue, and potato.

Erin'Oses. Ph;itoptides (gall mites).—
The irritation cause I by the bite of certain
acari, the Phytoptes, cause alterations in the
epidermal cells of the leaves which elongate
under the form of hairs and form a felt,
generally in the lower part of the leaves,
which may be white, yellow, rose, or rust
colour. This felt acts as shelter to the acari.
When these attack the shoit-- and the buds,
they are atrophied with formation of galls
liristling with prickles. Tliese diseases are
widespread.

Erin'Osis of Apple-Tree and Pear-
Tree. Eriniudi MaUnum et Pirinum. — •
Felting of uuder part of leaves, passing from
yellow and rose to rust colour.

Erinosis OF THE Gooseberry. Phytoptus
Ribis. — -This acarus sucks gooseberry buds
and leaves ; the lirauches never develop and
form packed bundles of leaves.

Erinosis of the Tine (Grise de la Vigne).
Phytoptus Vitis, Eriopliyes Vitis.- — Leaves
attacked l)y this Phytoptus show irregular-
shaped swellings on the upper surface, and
are coated on the under surface with down.
White at first, the down becomes red, then
brown, as it ages. This down, which cannot
be detached by rubbing with the finger, some-
times covers the whole of the under surface
of the leaves. Tlie upper surhice of the leaf
always remains green. These Phytoptes pass
the winter in the scales of the buds. This
disea-Si causes serious trouble, especially when
it attacks the young seedlings which require
complete development of their leaves to form
their roots.

Eriocami'a adumbkata. Selandria atra
(the slug-worm or slimy caterpillar). — Saw-
fly, of a brilliant black with a transversal
brown band on the upper wings. It measures
.'> millim"tres in length ami appears in the
end of July. The female lays its eggs on
tlie under surface of the leaves. The larv;e
are first of a blackish-green, then of an
amber-yellow and covered with a viscous
substance ; it vaguely resembles a small snail,
lience tiie name slug-worm. They devour
the jjarenclij'ma of tlie cherry-tree, tlie pear-
tree, the plum-tree, and the apricot-tree.
The leaves are reduced to the state of lace ;
growth suffers and the growth of the fruits
is stopped. Nymphosis takes place in tlie
.soil.

Ekioi'HYEs PiRi. I'hytoptiis Pin' (rust
of the ])ear-tree, V/ii!/u'> thi J'liirier). — This
disease is produced by aii acara.s which
dwells in the parenchyma of the leaf and

circulates between the two epidermes. The
irritation of its bites causes the formation of
pustules, the red tint of which on the young
leaves becomes brown and even Ijlack in a
few weeks. On the lower surface of the leaf
the epidermis is pierced with small holes
which allow access of air and of insecticides.

Ervsiphes. Mildews. — Mildews form on
the leaves and on the young parts of the plants
powderish, whitish spots. The mycelium of
the mildew is always superficial, it crawls on
the surface of the epidermis without pene-
trating into the interior of the organs. It
sinks its suckers in the epidermis. Mildews
produce uot only conidia, but also peritheca
which contain one or more asques ; all these
fungi under their conidia form have been
designated under the generic term oidium ;
they then exhibit such a resemblance to each
other that it is often impossible to distinguish
the one from the other.

Erysiphe communis (mildew of peas,
trefoil, etc.). — Attacks peas, haricots, lentils,
lupines, trefoils, and different crucifers. The
disease extends over the two faces of the
leaves. The plants attacked languish, and
a crop may lie entirely ilestroyed.

Erysiphe graminis (mildew "of cereals).^
It forms a persistent woolly coat, white at
first then red.dish ; grows in isolated spots or
on surfaces extending over the grain and the
leaves of cereals, particularly wheat.

Mildew of the Ash Leaf cind Hazel Leaf
(Phyllactinia sitffulta). — 'i!h.i!i mildew is
found on the leaves of the hazel-tree, the ash,
the hornbeam, the birch and the alder-tree.
It covers the two faces of the leaf ; the
covering is spidery, white and transient.

Mildew of the Gooseberry (Alicrosphcera
grossularicc). — This mildew covers the two
faces of the leaves with a greyish-white
spidery covering.

Mihhw of the Hop (Sphfemtheca Cas-
tagnei). — This mildew, distributed over the
most different plants, is particularly injurious
to the hop. It attacks all the female in-
florescences and destroys the crop. It very
often attacks the inflorescences of Spirea
uiinaria ; it is very frequent on the cucur-
bitaceae and in particular on melons and
pumpkins, on the compositie, plantains, pim-
pernels, veronicas. The spidery spots form
on both sides of the leaves.

Mildew (f the Rose and Peach (Sphce-
ruthera jmiiHosa). — -This mildew is frequent
ill gardens where it covers the young shoots
and buds of rose bushes.

EUDEMis (tortrix of the grape). Eudemis
liotrana. — -This small butterfly has the same
habits and clauses the same damage as the
co'hylis, but it has three generations a year
and thus attacks the inflorescence, tlie sour
graj)es (verjus), ,ind the ripe grapes. The
greenish caterpillar reaches 1 centimetre.
The insect commits its ravages more especi-
ally in Southern France.

E.xoASCU.s ukkou.mans (leaf curl of the
peach). — This disease is caused by the com-

GLOSSARY.

B93

plete deforniatiou of the leaves, which
thicken, curl, twist, and swell, assuming a
pale yellow to rose tint. When the <lise;xse
reaches a certain pitch, the young branches
are also iuvade.l and deformed. The mycelium
of the fungus which causes this disease is very
ramified ; it spreads ou the surface of the
epidermis under the cuticle, forming a sort
of perforated membrane. It applies itself
wholly against the nourishing cells and ex-
tends itself in the space between the cells.
By the action of the mycelium the cells ot the
epidermis and of the parenchyma multiply
in an abuorinal way. There is thus pro-
duced a homogeneous tlesliy tissue .leprived
of chlorophyll which forms characteristic
.swellings. The mycelium gives out asci at
a certain point which traverse the cuticle,
and impart to the deformed leaves a velvety,
whitish appearance. The spores developed
in the interior ot the asci are projecte.l out-
side, through a transversal aperture. They
are white sort of leavens, which pla'^ed in
water multiply indefinitely by budding.
The rust dojs not propagate itself from year
to year by means of the spores, but chiefly
by the mvcelium. The latter, which is per-
ennial, hibernates in the Ijuds whence it pene-
trates into the vouug leaves. The periodical
appearance of leaf curl causes great damage
to the tree ami finally kills it. Leaf curl
therefore causes great damage. The bites of
plant lice sometimes cause an analogous 'le-
formatiou of the leaves.

ExOASCUS PRONI (poaket or bladder
plumsK— This fungus is in all points com-
parable with the Exoasciis deformans which
produces the leaf curl of the peach, but
instead of deforming the leaves it loilges in
the pistils of the flowers which assume under
its influence an extraordinary development.
The pistil is converted into a sort of hollow
elongated pocket. Tiie mycelium is hardy
and passes the winter under the young
branches whence it penetrates in the spring
into the young pistils of the flowers.

FlDONlA PINARXA. (phaleua of the pine).—
Dark brown butterfly ; the upper wings of
the female are striped' with yellow bands, 4
centimetres from tip to tip, the male 3 centi-
metres. The caterpillars gnaw pine needles
which thev generallv cut through the miildle
and let oiiedialf fall to the gi-ouiid. The
ravages last from August to October. The
caterpillar is green with white and yellow
longitudinal lines. It reaches 3 centimetres
in length. It descends the length of the
trunk ill winter to metamorphose itself in
the moss of the soil.

Finger and Toe, see Anbury and

Pl.ASMODIOPHORA. BRASSIC.E.

FaMAGiNE. Capnodium (smut of fruit
trees).— Fumagine is the term applied to
the bla"k coating wliich appears on certain
plants infested iiv plant lice or cocliineals
.(s.-ale insects). Tins coating is formed by the
black mycelium of a fungus which lives
-solely on the saccharine liquid, the honey-
dew," which the insects project on the leaves
■without ever penetrating the epidermis to

extract food. The damages caused by this
fungus are .serious because they injure tiie
regular functions of the leaf, and they,
moreover, soil the fruit which they render
unfit for food. The cochineal and conse-
quently the fumagine are very injiiriou.s "to
trees especially in orchards.

FUSARIUM NOV. SI', (flax disease).— The
exhaustion of the soil in flax cultivation so
coniinon in America is due, according to the
researches of BoUey, to the presence of a fun-
gus which, in attacking flax plants, weakens
them ami eventually causes them to perish ;
growth is stopped, the shoots fade and finally
dry up.

FusicLADiOM CERASi (black spots of the
cherry). — This fungus, very analogous to the
foregoing, attacks cherries on which it pro-
duces small black-green velvety spots. The
cherries attacked late in the season ripen
without their taste being altered. However,
when the fungus invades the young cherry
of the size of a pea, the latter dries up,
browns, and withers before ripening.

Fcsici.ADiL'M PIRINDM (pear scab, pear
holes). FnsUiadium dentritkum (apple scab,
holes of the apple).— These two fungi are
very analogous, and do the same damage,
the one on the pear-tree, the other on the
apple-tree. The Fusidadinm pirinum a,t-
tacks the leaves, branches, and fruits of the
pear-tree. .Numerous dark spots appear on
the leaves which become pulverulent and of
a black olive-green. On the young shoots the
fungus also forms black spots and speckled
places which become more or less deep holes
on the branches, kill tlieir extremities and
dry up the buds. The fruits covered with
black spots are soon deformed and holed as
they grow, thus losing all their value.
Certain varieties, like the Dni/enne d'hiver,
are particularly sought after by this fungus.
Black conidiophora are to be seen on examin-
ing the leaves as well as tlie branches and
fruits ; they are formed on the mycelium
which extends into the superficial tissues of
the organs attacked ; numerous spores fall
from their summit. The conidia germinate
very easily in a few hours when they fall
into a drop of water ; their gernunative tube
glides some time on the surface of the fruit,
there ramifies, and finally pierces the epi-
dermis where it chiefly grows without fixing
itself deeply into the neighbouring tissue.
In winter spermagouia are formed on the
branches which transmit the disease from
one year to another. Moist seasons greatly
favour this disease. Fusic/adiuw di-ntriticHin
produces ))lack velvety oUve-green-co^'ered
spots on the leaves of the apple-tree, on the
fruits brown or dark spots, sometimes iso-
lated, sometimes confluent. The skin of the
fruit is killeil on the space occupied by these
spots and ends in Ijeing replaced by a layer of
cork. When the apple is invaded early the
skin may l>e killed over a large surface. The
latter not being able to keeji \\\> with the
growth of the flesh of the fruit, it follows that
the apple grows irregularly and that it forms
hollows more or less deep under the diseased

394 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

parts. When the apple is attacked late
the damage is confined to spots which,
without preventing ripening, greatly injure
its appearance and depreciate its market
value.

Galeruca of the Elm. Galeruca cal-
mariensis. — The larva of this insect is as
injurious as the perfect insect. The eggs
laid on the leaves hatch in May : the larvae,
very voracious, reduce the leaves to skeletons
up to the time thej- nymphose, Siv up to
August, when they descend the trunk to
bury themselves in tiie soil. The paren-
chyma of the leaves being gnawed the veins
alone persist, and the leaves, reduced to a
skeleton, soon fall. The tree then towards
the end of summer presents quite a winter
appearance. If their ravages occur two years
in succession they may kill the tine.st trees
on a promenade.

Gall Mites, see Ekinosis.

Gangrexe of the Stem of the Potato
(disease caus:'il by the Bacillus caulivorus
which especially attacks plants from cut
potato seed). — -The diseased stem is greatly
altered in its lower part. The disease ex-
tends from the surface of the soil to the
leaves, the infected plants soon die.

Glceosporium frotigenom (bitter rot of
the apple). — • This disease, prevalent in
America and in England, is characterized bj'
brown spots which are produced ou the
green apples ami are covered by black dots,
the pycnides of the fuugus. The spores do
not appear to attack the apples except at the
wounded spots.

Glceosporidm Jcglaxdis (disease of the
leaves of the walnut). — -Fungus, which pro-
duces on the leaves of the walnut large red-
dish-brown or greyish spots on which black
pycnide.s are observed.

Glceosporium nerviseqcdm (plane [pla-
tamis) leaf scorch). — This fungus attacks
the veins of the leaves a little after their full
growth. Towanls the middle of May great
withered spots form on the leaves with veins.
These leaves soon fall.

GLffiOsi'ORiUM uiBis (currant leaf spot).
— The disease produces withered spots on
the leaves and causes them to fall in mid-
summer. A numl)er of small spots are pro-
duced on the upper surface of the leaves
attacked. Tliese spots are produced by the
organs of fructification of the fungus and
are still covered tiy the brown epidermis of
the leaf, whicli bursts at a certain moment
to let the spores escape.

GLtEOSPOKiUM VENETa.M (raspberry spot).
— This fungus produces grey spots liordered
with red on the stem and leaves of tlie rasp-
lierry. They so damage the plants that the
fruits do not ripen.

Grai'HOIJTHa W(EBERIana (tinea of stone
fruit trees) ; Tortrix (Carpocapsa) Weber-
lANA. — The caterpillar of tliis niii-rolepi-
doptera jierforati's the Viark of })lum-trees,
peach-trees, aprieot-trees, and alnion<l-trees,
I)enetrates into the alburnum and there
umlerpoes metamorphosis. It kills the bark
by the wounds it produces ; it causes canker

and a flow of gum. It prefers the peach and
the plum.

Gkyllotalpa vaLGARls (mole cricket). —
The mole cricket lives almost entirely on
insects and their larvae. To search for this,
underground food it cuts all roots that hinder
it. It passes the winter in the earth at
depths varying with the temperature aud
moisture, then in the spring it re-ascends
to within a few centimetres of the surface,
where it excavates numerous runs, which
end in a vertical hole, which gives access to-
the burrow properly so called. The in-
vasions of the mole cricket are not spon-
taneous ; it takes about twelve years for the
number of these insects to increase so far as.
to render culture impossible. The existence
of each insect is three years ; the female lays-
200 eggs, but in spite of this great fecundity
multiplication is comparatively slow. Short
of food the mole crickets eat each other.

Gum. Uummosls (baciUary of the vine).
French terms : Roncet, (Jelivure, Aubertiage,
Moragement, Corirtnoue, Dartrose, Mai
new. — This disease is due to the parasitism
of a bacteria. The damage of the tissues con-
sists in a gummy degeneration of the wooil.
It is believed that the disease enters through
the pruning wounds, for this disease gains-
ground more especially from top to bottom.
At the same time as the disease propagates-
itself towards the roots the bark becomes-
hollow on the shoots, aud big fissures are
formed on that year's branches. The dis-
eased stems languish, wither ; the branches
become stunt-Al, the leaves fall prematurely,
and numerous shoots spring from the foot of
the stocks. The vines eventually die.

GcTMMOsis OF Stone Fruit Trees (cherry
leaf spot). — The fungus Cori/neioii Beyer-
inckU is regarded as the chief cause of the
gum of stone fruit ti"ees, known under the
name of spot of stone fruit trees.

GvMxosPORANGiUM SABIX.E (pear leaf
cluster cups). — This uredina is heteroic ; it
has its spermogonia and aecidium forms on
the pear-tree, its uredo and teleuto forms-
on the Jii.nijier Sahinns, oxycedar of
Virginia. When the relation which exists
between these two forms of the same fungus,
was unknown, one was called lioestdia caii-
cellata, the other Gi/wnosporangium Sabinw
ft fuscum. The disease appears on the
pear-tree in the spring. It forms big
yellow spots on the surface of the leaves,
spots which are besprinkled witii purple-
red spots, the spermogonia. At the end of
the year these sj)ots form white excrescences,
on the lower surface of the leaves, a sort of
irregular galls, whicli contain aeci<lio spores.
VViien these s[)ots are numerous the growth
of the pear is gre^itly weakened, but the
parasite becomes especially dangerous to the
crop when it attacks the fruits. It then
forms irregular swellings. The fruits st>
hypcrtrophied are stopped in growth ami
are absolutely valueless. The aecidium form
lives in the sj)riug-time on the juniper. The
destruction of junipers causes the disease to
disappear.

GLOSSAEY.

395

Hadena Bkassica (cabbage moth).
Mamestra Bmsxkcv.—Tav caterpillai-s of
several noetua ravage cauliflowers and ordiu-
ary cabbages, fspecially when they are
hearted. They form numerous holes aud
penetrate to the core.

Haltica Uheleiu. J'unaises des Cap-
sides. — This bug sucks the leaves of the
potato.

Heterodera kadicicola. — Nematode,
which lives as a parasite on the roots of very
ilirt'erent plants, but contrary to the nema-
tode of the beet produces galls on the roots.
These galls shelter the worm during the
whole of its development. They sometimes
reach the size of a pea, and generally have
onlj' a very sliijhtly unfavourable influence
on the plant as long as the worm remains.
As soon as the worm quits it the galls rot
and cause the roots to rot. On annual plants
the presence of the.se nodes is not to be
feared, as the rotting of tlie gall coincides
with the harvesting of the plant, but on
hardy plants aud trees their effect makes
itself felt by lowering the crop from these
plants. It is thus that this eel-worm pro-
duces swellings and atrophes on vines,
resemblincj those produced by tlie phyl-
loxera. This parasite prefers moist soil. In
Italy and Portugal the destruction of several
vineyards bv the accumulation of this nema-
tode is reported.

Heterodera Schachtii (nematode of the
beet). — This microscopic worm is met with
on tlie roots of different plants, such as the
cabbage, spinage, colza, but it commits its
depredations especially on the beet. The
larvae of the nematodes prick the radicles of
the beets with tlie dart with which they are
furnished, and flx themselves by the head in
the cellular tissue. These insects increase
very rapidly, for each female can lay 400 eggs
and produce three generations a year ; their
vitality is thus very great. Aime Girard
showed that they may resist an interval of
three years fallow. It is also recognized that-
they may traverse the digestive tube of
animals fed on beets without their vitality
suffering. They may thus be propasrated by
farmyard dung, and it is therefore indLspens-
able to disinfect it by carbon disulphide. The
disease is recognized by its exterior cliaracter.
In summer tlie old leaves of the beet turn
yellow and die. The centre leaves only grow
.slowly. The root thus remains small, and,
according to Holl rung's analyses, it contains
little sugar. The presence of the nematodes
may thus appreciably diminish the value of
the crop.

Hydnum Schieder.mayrt. — This fungus
is an apple-tree parasite which rots the wooil.
It bores the trunk, forming great holes of rot,
whence issue in autumn irregularly shaped,
yellow, fleshy receptacles, which may reach
5 centimetres (2 inclies) in duimeter and 10
centimetres (4 inches) tliick. They smell of
anise.

HvLEsrNES.— These are Sjolytides, which
are distinguished from the bostrichus by
their elongated legs and their corselet narrow

in front. The larv;v and the perfect insects
dig burrows in the trunks of trees.

Hylesixus piniperda (tlie pine-destroy-
ing beetle). Jardiuier de lu Foret. — Black
insect, 4 millimetres, which appears in July
aud pierces the bark at the b;ise ot plants of
a few years' growth ; it there penetrates as
far as the medulla and ascends the young
tree, emptying it as far as the terminal bud,
through which it issues. At the approach
of winter it takes refuge in the moss. The
female lays its eggs in the spring in a single
sinuous l)urrow made in the liber ; the larv«
afterwards excavate lateral burrows there.
There are sometimes two generations yearly.
It attacks the Pin us si/lrestris (the Scots
pine), Pi ails nvtritimus (the maritime pine),
and Pi mis lariciu (the aleppo pine).

Hylobius abietis (the spruce pine wee-
vil).—Brown, red-haired insect, 1 centimetre
long. It appears in pine and spruce forests
in May. The females lay their eggs at the
foot of old trunks. The larvse pierce burrows
in the bark. The adults are more injuriou-s
than the larvse because they gnaw the termi-
nal buds of the pine.

Hylotoma ros.e. — Rose saw-fly of 8
millimetres ; black ^yith red abilomen. The
green larvse gnaw the leaves of the rose-
trees, only leaving the veins.

Hypomyces perniciosus. Myciifioni' per-
iiiciosa (mole disease of the mushroom). —
Mushrooms attacked by the mole grow in an
irregular manner, swell, puff up, and become
deformed to such a pitch as to be nothing
but an irregular-shaped mass. This mass is
covered in places b\' white spots and easilj-
rots.

Hyponomecte of the Apple-Tree (tinea
of the apple-tree) ; Hypoxo.MKUTa MaLIN-
ELLA (small ermine moth). — Small butterfly,
the upper wings of which are white and
covered with black spots. The butterfly
lays its eggs in August on the branches
of the apple-tree. The larvte hatch in
September and pass the winter in a tissue
of coarse silk, from which they only issue
in May. They then go on to the buds
and the young shoots, envelop them with a
silky fabric which acts as a shelter, aud thus
live together to the detriment of the paren-
chyma of the leaves. As soon as the leaves
of one branch are destroyed the caterpillars
pass to another. A few nests of these cater-
pillars are capable of devastating a whole
tree, which in summer would appear rusted,
as by a late frost. The caterpillars assume
the chrysalis form at the end of June in
small white elongated cocoons, collected in
mass in a protective fabric.

Lachnosterxa arccata (red cockchafer),
the larva of which gnaws the roots of vines
and strawberry plants in America.

Leptinotarsa decemlineata (the Colo-
rado beetle).; — Deep yellow coleoptera, closely
allied to the chrysomelMes ; 1 centimetre in
length with Ave black longitudinal lines on
eacli elytrum. This insect does great damage
to potato fields in America. It gnaws the
leaves as larva as well as in the perfect state.

396 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

.and produces abortion of the tubers. Very
energetic raetliods are adopted to prevent
it being imported into France [and Great
Britain]. It sliowed itself in Europe as far
back as 1S77, but the sources of infection
have been destroyed each time that it has
been observed.

Lethrus cephalotes (big-headed leth-
Tus). — The lethrus is a sort of bousier (cow-
dung insect?) which is injurious to vines.
It is 2 centimetres long, its body is globular
and black. The lethrus is chiefly met with
in Russia and Austria-Hungary. It is noc-
turnal, and digs its burrow near the stocks.
Before dawn it issues from its hiding-place
to ascend the vines and cut the young vine
shoots at tiieir base, and carry these into its
burrows.

Leocania dnipunctata. — The caterpillars
of this tortrix penetrate inside grass stems
and thus greatly injure nieailows.

LOPHODERMIUM PINASTRI (pine leaf cast).
— Fall of the leaves of the pine. This para-
site commits great depredations, especially
in nurseries of two to three years old. As
early as the autumn of the first year the
seedlings are invaded and the leaves are
spotted with brown and become red. Spermo-
gonia are formed ; as these grow the leaves
wither up completely. The black perithecae,
larger receptacles than the spermogonia, are
not formed until the following year on the
same spots. After prolonged wet weather
the pyrothecie open through a slit and show
the asci filled with a bundle of spores.
Tliese spores spread the disease. Special
weather conditicnis — a mild winter and a wet
summer — gi'eatly favour the growth of this
parasite. It may then devastate a nursery.
The young plants attacked by the rouge
may be regarded as lost, but if part of their
leaves remain intact they may rehabilitate
themselves A plant attacked by the rouge
is too weak to l>e transplanted.

LoPHYRUs PINI (pine saw-fly). — 1 centi-
metre long ; head black, corselet yellow with
black spits, abilomen yellow. The females
lay their eggs iiisMe the pine needles ; the
green larvie gnaw the needles and weave
against the leaves small cocoons of brownish
wilk. The second generation appears in July,
the third in October. This generation nynv
phoses and lays its eggs in the moss at the
foot of the tree.

Lopus SULCATOS. (iriaeUp, (If la, Viijn". —
Tills Ijug of 7 millimetres with yellow bands
and points, appears at end of May and at-
tacks the flower buds of the vine, sinking
its sucker into them. The female lays its
eggs in the cracks of the l)ark and tlie crevices
of the vine ])rops, ))referably in the medulla
of the cut vine shoots. The larv;e hatch in
tlie following s])ring and spread first on
grass and on mustard, and tlicn on the vine.

Luc.'ANUs CERvas (stag-licetle). ^ Large
(.•olcoptera, -'M centimctn^s long, furnislied
with very higldy develoi)ed deer-horn-shaped
niandiblrs. The larva;, the development of
which takes four to five years, bore holes in
the trunks of the oak, birch, and beech.

Lyda campestris (pine saw-fly).— Black
and yellow fly, 2 centimetres long, yellow
wings, appears in June, and does the same
damage to pines as the L. pratensis does to
meadow plants. The larva buries itself in
the moss at the foot of the stem in the
month of August, there to pass the winter.

Lyda ERYTHROCEP{L\LA.^The larva at-
tacks pine needles and hides itself at the foot
of the tree in June.

Lyda pratexsls (meadow saw-fly). — Yel-
low and black fly, 13 millimetres in length.
It flies in May. The larvae, 2 centimetres,
are brown with a yellow head. They gnaw
the leaves ami descend in the month of August
into the soil to pass the winter in a sort of
lodge.

Lygus pratensis (meadow bug). — This
bug is sometimes very injurious to apple-tree
and pear-tree buds.

Merulids lacry.mans (dry rot). — This
fungus, aUieil to the Polypora, is not a para-
site of the wood of our trees but is the most
dreadful destroyer of building timber. In
Europe it is widespread and does great
damage. It chiefly attacks resinous woods
and produces the dry rot of pine timber and
pitch-pine. It sometimes also attacks the
oak ; its development is favoured by mois-
ture. When the presence of this parasite is
reported in a town it is necessary to take
great precaution to avoid contamination of
construction timber. If one spore is laid on
the surface of one of these timbers it will
suffice to contaminate the whole house.

Mildew, see Brysiphes.

Mole Cricket, see Gryllotalpa vul-
garis.

MoNiLiA frutigena (brown rot of stone
fruits). — This fungus causes great ravages,
especially in America, in peach nurseries.
The disease is characterized by the browning
of the fruit, the flesh of which shrivels up,
becomes as hard as horn, mummifies, and
finally otdy forms a haril layer round the
stone. The mycelium which lives in the in-
terior of tlie pulp fructifies the same or the ■
followhig year. Perennial during winter in
tlie withered fruit, it revives in the spring
under the influence of the heat, and produces
grey tufts t^onsistiug of wreaths of spores
which spreail the disease. In Europe it is
especially a wound jiarasite. Fruits, whether
stone or pi]) fruits, may be invaded by it,
especially if wounded.

Mulberry Dise.vse, Bacterian. — Boyer
and L;imber discovered that this disease is
due to the /> irfi'riiiin Marl. It shows itself
on the outside by lirown-black spots on the
lower face of the leaves an<l the branches ;
on the latter the spots are elongated and
are eroded in the form of more or less deep
cankers. The disease begins on the top of
the brandies, wliicli apjicar carbonizi^l over
a certain length anil l)cnt in the form of a
cross. The leaves soon wither, rolling up
towards the midrib.

Neotria cinnauarina (necrosis of wood ;
coral spot disease). — This fungus, which
generally lives as a saprophyte on dead

GLOSSARY.

397

wood, appears also as a parasite and corrodes
tlie woad. It attacks the horse cliestuut,
the maple, the ailantus. Its mycelium not
ouly extends into the bark but uito the wood
itself ; it is a parasite of the ligneous body
like the polypone, which live at the expense
of the starch. The corroded wood no longer
serves for the passage of the sap and the
tree dies eventually. In the autumn this
diseasa is easily recognized, for there is seen
to appear, across the dea<l bark, cushions of
stroma which become covered with conidia
on which the peritheca are produced. This
visible form is termed Tubercularia rulfjaris.

Nectria ditissima (canker of the apple-
tree, the pear-tree, ami the beech). — Tins fun-
gus is the immediate cause of some cankers
which gnaw the branches of the apple-tree
and the pear-tree. It is one of the most for-
midable diseases of fruit trees. Cankers are
generally bordered with small coral red points
which are the peritheca of the fungus ; they
form real wounds in the bark which do not
cicatrize and which always extend and sink
deeper and deeper. On the edges of the
wound the still healthy tissue forms swell-
ings, but these are rapidly destroyeil by the
fungus. This corrosion hinders the circula-
tion of the .sap, the trees languish, become
covered with dead wood, and produce no
more fruit. The first phenomena explains
itself on the outside by a point of bark which
becomes depressed, forms concentric fissures
and causes the bark to tear, which falls in
strips. The mycelium is not only found in
the bark but in the ligneous body and in
the interior of the vessels, and the cells of
the ligneous parenchyma. It multipliers in
the midst of the disorganized tissues. The
woolly aphis prepares the way of access to
this fungus.

Nematodes Injurious to Cultivated
Plants. — These are smaU worms of a filiform
aspect, a smooth tegument, which live in the
interior of plant tissue, causing character-
istic deformations of the organs attacked.

Nesi.\tus ventricosus, Nematus ribis
(gooseberry saw-fly). — The larvae of these
saw-flies attack diS"erent species of goose-
berries, entirely deprive these shrubs of their
foliage, and thus prevent the development
of the fruit. During May the larva which
is adult descends into the ground to turn
into a grub. After three weeks the insect
hatches and forms a new generation.

NocTUA : Agrotis, Mamestra, Plusia.
—The noctua are moths, they are not so heavy
as the bombycides. The wings avj char-
acteristic ; the upper, darker than the lower,
have two spots. The caterpillars ai-e glab-
rous, greyish ; they do not spin acocoon, they
pass into chry.salides in the soil.

Noctua gam.ma, Plusia gamma. — Grey-
ish-brown moth of 4 centimetres with a
silver spot which represents the Greek letter
Gamma on each of its upper wings. The
moth flies in the daytime, the green cater-
pillars have an appearance which recalls the
citigrade spider. They attack leaves of the
most diff"erent nature : cabbage, beet, potato,

colza, heiiip, flax, maize, peas, beans ; there-
may be two or three generations a year.

Noctu.v of the Lettuce. Polia dysodea^
— Noctua, the wings of which are of agi'eyish-
white with more or less dark-coloured bands-
and spots. The caterpillar of pale green
with three dor.sal, longitudinal brown stripes,
gnaws the leaves and the seed of lettuce.

Noctua of the Pixe. Trarhm ijini-
perda. — Butterfly, Ih centimetres long, head,,
thorax, and ujjper wings, red, with yellowish-
white spots and lines on the latter. The ab-
domen and the lower wings gi-eylsh-brown.
The female lays in April on the needles of
the Pin Hs sylvestris (Scots pine). The cater-
pillars attack the young shoots ; they are
green with white and orange longitudinal
l.iands ; they reach 3 centimetres in length in
July ; they turn into chry.salis in the moss
at the foot of the tree and there pass the
winter.

OiDiUM OF the Vine. Uncinula ameri-
cana, Oldinm Tuckeri.—Uhe mycelium of
this fungus lives on the surface of the plant
and draws its nourislmient from the cells of
the epidermis by numerous suckers. The
organs attacked are rapidly altered, the ex-
tremities of the young shoots wither, the
leaves shrivel up ami die, but the eft'ect is
still more deadly on the gi-apes, which crack
and rot. Tlie oidium, which is propagated
by its conidia during the whole growing
period of the vine, may entirely destroy a
crop. The worst attacked plants may, how-
ever, again become vigorous if the disease is-
arrested in time. The oidium may be recog-
nizer! by the white or greyish efflorescences
on the parts attacked. The oidium first ap-
peared about fifty years ago. The disease ap-
peared to attack certain varieties of vines with
a black grape. La Folle Blunrhe of Char-
entes and Armagnac was not attacked untQ
five years later. Owing to the oidium the wine
crop of France fell from an annual produc-
tion of 50,000,000 hectolitres (1,100,000,000
gallons) to 22,662,000 hectolitres (498,564,000
gallons) in 1853 to 10,824,000 hectolitres
(238,128,000 gallons) in 1854. This produc-
tion was the smallest of last centurj-, for-
even in the acute period of the phylloxera it
was not reduced below 25,000,000 "hectolitres
(550,000,000 gallons).

Opatrum sabulosum.— This insect of the
family of tenebrionides appears in May. It
attacks the buds of grafts from American
stocks, especially when they are earthed up.
The larvffi live two years in the soil.

Ophiobolus graminis (disease of the
lower part of the steraof wheat).— Laid wheat
Is due to the inva-sion of the winter nodes
nearest the soil by a fungus which, in damag-
ing the stalk at the level of the soil, is often
the cause of the laying of the straw of
cereal crops. The mycelium develops in
the interior and the exterior of the tissue.

Orobanche minor (orobanche of clover,
broom rape). — The orobanches are para-
sitic phanerogams of the roots. They live
exclusively at tlie expense of the plant on
which they graft them.selves for they are-

398 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

deprived of chloropliyll. The .seeds only
germinate in, contact witli the roots of the
nurse plants. They plant themselves there,
and their root which is a mere sucker pene-
trates, whilst it ramifies as far as the vascular
bundles. These root suckers are perennial if
the orobanche is fixed on a perennial plant,
and the multiplication of this parasitic plant
may take place without the intervention of
its seed. This is especially the case with
the orobanche of clover.

Oryctes nasicornis. Rhinoceros. — The
larva of this large insect resembles an enor-
mous white-worm. Generally it lives almost
exclusively on decomposing vegetable matter,
in melon beds, and in dung in gardens. Per-
roncito regards it as being the cause of
damages done in Italy to the roots of vines.

Pkar Leaf Cluster Cups, see Gymnos-

PORANGIUM SaBI.V.E.

Pentatoma Olerace.e (cabbatre bug). —
Green bug with red marks on the female,
white marks on the male, 6 millimetres long.

Pentatoma ornata (the decorated bug).
— -Piebald bug, red and black, 1 centimetre
long. The female lays its eggs on the lower
surface of the leaves, they are placed so as
to form bands. The larvae, like the adults,
suck the juice of the leaves.

Pentatomides (bugs).- — Several species of
pentatomides, known vulgarly as bugs, live at
the expense of the crucifers. Owing to their
large number they may cause great damage
in cabbage fields by sucking their juice.

Pentodon punctatus. — This coleoptera,
injurious to \ines,much resembles the bousier.
Its larva, which when full grown is twice
the size of the white-worm, lives in the soil
to the detriment of the new plantations of
grafted American vines, for which it has a
marked preference, of which it gnaws the
young wooil for two to three years.

Peritelus griseus. — This little Aveevil
nightly attacks in hundreds the buds of the
vine and fruit trees. It preferably hides
during the day in the buds or in the soil at
the foot of the vine.

Peronospora (mildew and white rust). —
FuuL'i of which the mycelium lives in the
interior of the tissues and which produce on
the surface of the attacked organs whitish
tufts resembling blights. They are chiefly
distinguished Iiy the fact that their mycelium
lives in the interior of the tissues whilst tlie
blights crawl on the surface of the organs
attackeil.

Pekonospora ahborescens (mildew of
the poppy). — -It attacks the leaves and the
inflore.scenrcs and may cause great damage.
The conidiiijilinra are on the lower part of
the organs attacked and form a white, then
yellow velvety coating. This Perono.yjoni.
attacks different species of poppies.

Peronospora oAwa.iFORMrs (lettuce mil-
dew).— The lettuce mildew d<ies not attaclc
l(!ttuies alone but different otlier coin-
])osite ])lants. It often attacks artichokes,
i-.liicories, and cinerarias. There are annu-
ally grown by mark(!t gar<leners (French)
about 2,000,000 lettuces, of which the Pero-

nospora f/augliformis sometimes destroys a
third. It app-iars chiefly on the salads
forced in beds to sell as early vegetables.
The leaves are covered, especially Ijelow, with
white efflorescences formed by the eonidio-
phora. The couidia germinate very easily,
without, however, forming zoospores like the
Peroauspora viticola, by issuing directly a
germinative tube which penetrates the leaf
and creates in the cells a new mycelium.
The leaves invaded commence by yellowing,
they then dry or rot. In the atmosphere,
continually moist aud warm, which reigns
under the frames, it will be seen that nothing
is opposed to the rapid progress of this dis-
ease, and that the ravages may become con-
sitlerable. The organs of propagation from
one year to another are the oospores which
are formed in the debris of the dead leaves.
It is therefore necessary never to throw them
with the dung which will form the mould of
the following crop, but to destroy all the
diseased plants. To avoid invasion, it is
well to select new soil into which to trans-
plant the lettuce.

Peronospora Schachtii (mildew of the
beet). — Beet crops are sometimes ravaged
by beet mildew. The parasitic fungus which
produced this disease preferably attacks the
young leaves, thus becoming in many cases
one of the causes of the rot of the heart of
tlie beet. Amongst beets, the leaves of
which have been attacked, the amount of
.sugar contained in the roots is always con-
siderably diminished. Like that of the mil-
dew of the vine the mycelium of Peronospora
Schachtii crawls lietween tlie cells of the
plant and pushes the grey lilac conidiophora
through the stomata, especially to the lower
surface of the leaves. The detached conidia
germinate freely in water and their germina-
tion tube pierces the epidermis of the leaf to
instal itself there. Dormant spores (oospores)
are formed in autumn in the attacked leaves.
This disease is, therefore, propagated by the
leaves of diseased Ijeets from one year to
another. When the disease exists in a field
the leaves must be destroyed and not carried
to the stable nor the dunghill. Tliey are
buried on the spot. Rotations greatly pre-
vent the spread of this disease by oospores.

Peronospora Schleioeni (mildew of the
onion). — This mildew causes great damage to
onion crops. In wet weather it may assume
such an extension that the whole of the
plant is invaded and all tlie onions perish
rapidly. Like all Peronospora the mycelium
lives in the interior of the leaves, especially
the young ones, ami discharges conidiophora
through the stomata. The conidia which
are deta<'hed therefrom are the organs of dis-
semination during summer, and the oospores
formed in tiie dead leaves transmit the dis-
ease from year to year. The stoclcs attacked
liy this parasite have leaves with yellow zones
which wither ; tlie plants become yellow and
Knally die.

Peronospora tiukiilkiku.m (mildew of
clover). — This fungus attacks clover, lucerne,
and a great many leguminous plants. When

GLOSSARY.

399

the disease declares itself in a wet year in a
lucerne field, the crop may be regarded as
lost. Living in the interior of the leaf the
mycelium emits conidiophora which cover
these with a white or grey lilac flock surface ;
the leaves attacked are discoloured, wither
and fall.

Peronospora VICI.E (mildew of the pea
and the vetch). — This mildew, which attacks
different species of peas and beans, is dis-
tinguished by a dense lilac Hock surface
formed on the leaves. The organs of pro-
pagation and dissemination are the same as
those of PeroHuspora.

Peronospora viticol.v (mildew of the
vine).— This fungus has great analogy with
the Phytophthiira. It prefers to ^ow on
the leaves of the vine, Ijut it also invades
the young branches, the flowers, and the
grapes. " (Brown rot, grey rot, juicy rot. )
The leaves begin to grow yellow on the at-
tacked vines, then the spots are intensified
and the vines assume a reddish-brown colour.
This fungus lives between the cells and the
parenchyma and on the under surface of the
leaf emits conidiophora from which the
conidia or summer spores are detached.
These ripen in a night and germinate as soon
as they fall on a leaf rendered moist by the
dew or by the rain ; they produce mobile
zoospores. After a sojourn of half an hour in
a drop of water, they fix themselves, emit a
germinative tube which pierces the epidermis
and penetrates into the interior of the leaf.
Late in the season, winter spores are formed
in the leaves which remain active and live
in the withered leaves. In the spring the
spores spread the disease. Mildew appears
early in May and June. The disease is often
arrested after the first spring invasion by
the drv heat of summer, but only by a
heat of' 20° C. (68° F.). If the air be moist
the disease spreads n^ore energetically and
makes rapid progress. I'lrroniispnra does not
rest like the I'lif/tnpliflmrd. in the perennial
state in the plant during winter ; it torms
in autumn oospores in the attacked organs
which liatch in the spring and again start
the ilisease. The organs of dissemination are
especially tlie summer spores or conidia which
are formed by thousands on the tufts of
conidiophora on the lower surface of the
leaves and during the whole summer. These
conidia, fortunately, are not endowed with
the same vitality as tlie oospores. Cold and
dryness destroy them easily. Moisture, on
the contrary, keeps them alive, but however
great it may be, this moisture does not
suffice to make tliem germinate. It not
only requires the direct contact of water
with this spore to cause germination, but a
surrounding temperature lietween 17° and
30° (62-6°-S6° F. ). About 17° C. the conidia
take about two days to liatch, from 25° to 30°
half an hour suffices. The fine drops of dew
in warm weather are especially favourable to
the hatching of the disease. Looking to tlie
great number of coniiiia formed, it will be
understood why, when the conditions are
favourable to their germination, the invasion

is so suddeTi and so general and why iu
summer in drj' weathci mildew causes no
damages.

Phai.enides or Geomrtrides. — Butter-
flies with a rugose body and large wings,
generally nocturnal. The caterpillars afe
called geometers or arpenteiises, owing to
their metliod of walking iu the form of an
inverse U.

Phoma Tabifica (beet and mangel rot). —
The disease of the heart of the beet is iu
certain cases the result of the invasion of a
fungus. It reaches its height in September.
In August leaves appear on the beet which
droop as if faded ami finally wither more or
less completely. That is due to damage to
the petiole of the leaf, which shows over a
great part of its length a whitish withered
spot surrounded by a brown aureole. The
disorganization is propagated, following the
bundles, as far as the heart of the beet and
kills the whole of the young nascent leaves.

Phylloxera of the Vine. I'lu/Uoxera
vastatrix (aerial and subterranean). — The
adult female lays a single q^s, on the wood
of the aerial part of the vine called a winter
egg. The young apterous phylloxera which
issues from it either immediately gains the
roots or the leaves of the vine, on which it
produces a characteristic gall doing little in-
jury to the plant. This aerial form or galli-
cole of the phylloxera is rarely found on
French vines, but it is very widely spread
on American vines, the roots of which are
not generally invaded by the insect. The
aerial form of the phylloxera does not belong
to the indispensable cycle of the very curious
evolution of this insect. The young phyl-
loxeras which descend to the roots prefer to
fix on the radicles to introduce their dart
there and to remain fixed at the same spot,
continually sucking the juice of the plant.
By this constant irritation, first the bark
swells, then hypertrophy of the cambium,
hence the formation of tumefactions. After
the death of the phylloxera these nodosities
rot and cause tlie decomposition of the root.
The large number of phylloxeras fixed on
all the roots rapidly cause atrophy of the
radicular system, and by that fact alone the
vine languishes even in the first year and
may die in the second. The phylloxeras
of the roots are always females or rather
parthenogenetic subjects which breed with-
out .sexual intercourse. Each individual
lays dailj' -30-40 eggs or gemmations, the
eggs of which hatch in eight days. Twenty
days after their birth they are reproduced
in the same way. With fi-S parthenogenetic
generations yearly an individual may repro-
duce thirty milUon descendants. Amongst
the last gemmation of summer there are eggs
which give birth to a new winged form which
abandons the roots, ascends the plants, and
disperses itself in the vineyard. This form is
also parthenogenetic ; it lays on the aerial part
of the plant four eggs which hatch new sexual
forms, male and female. These individuals
are deprived of digestive organs and do not
therefore take nourishment. Coupling oc-

400 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

curs bstweeu these two new forms and the
female lays iu autumn the single egg re-
ferred to above. It will thus be seen with
what rapidity a hot-bed of phylloxera may
extend and propagate itself in the neighbour-
hood. In the south of France the phylloxera
first appeared about 1863. In 1865 a real
invasion was reported near Aviguon and at
Floriac, near Bordeaux, which spread rapidly.
It was not uutil 1868 that Planchon dis-
covered the cause of these ravages, the Phyl-
loxera vastatrix. This aphis was akeady
known in Anierica under its gaUicole form
since 1854 and in Great Britain where it ap-
peared iu the greenhouses as far back as
1863. In 1877 it invaded the department of
Loir and Cher, wliere in the first year it de-
stroyed 288,000 hectares of vines (720,000
acres); in 1881, 429,000 hectares (1,072,500
acres) shared the same fate, and in 1888 half
of all the French vineyards were invaded or
destroyed by this f(ini[iila1)l(' parasite. In
that way the crop iliminishe<l considerably ;
iu Vaucluse, for example, it fell in 1876
from 400,000-500,000 hectolitres (8,800,000-
11,000,000 gallons) to 49,000 hectolitres
(1,078,000 gallons). It was only from the
beginning of that time, that is in 1874 and
1876, that the phylloxera reached Germany
and Switzerland. Energetic measures were
taken to prevent the propagation of this
insect, and the importation of vines from
contaminated countries was prohibited.

PlERls Brassic^. Pleria Rape (large
white cabbage butterfly, small white cab-
bage butterfly). ^They are white, diurnal,
well-known butterflies. The former female
lays its eggs in June on the surface of the
cabbage leaves where these masses form
plates of a white colour ; the f-jmale of the
.second lays its separate eggs in packets. The
caterpillars of the former are greenish-grey
with three longitudinal lines aud reach 5
centimetres in length ; that of the second are
green with three yellow longitudinal stripes.
There are two generations a year. The cater-
pillars attack all cruciferre ; they are danger-
ous because they ai)i)ear iu very large numbers
and gnaw the leaves, leaving only the veins.

PissoDES NOTATUs (small ])ine weevil). —
A smaller-sized weevil than the large pine
weevil, 8 millimetres long, brownish-red with
elytra strij)ed with two whitisli cross bands.
It attarks ])inc |)lantations of four to eight
years whicli it devours in the adult as well
a.s in tlie larva state. The ])crfect insect,
which appears iu May, gnaws the terminal
shoots and buds, especially those of the
I'iiins sj/lmdrin or of the Weymouth pine.
The female lays its eggs in the bark of the
lii<?h parts of the tree. The larvffi bore
siiiuoUH holes between the wood aud tlie
bark ; tliey turn into grubs iu these lioles.

Pi,AS.MOUioPHOiiA BitASSlC/K (Anbury,
linger and toe). — 'I'liis disease; is charac-
terized by eX(T(!Scences on the roots. It
causes stoppage of growth ami kills the
plant. This disease may attack all varieties
of cabbage, as well as bci^ts, turnips, and
nulishes. The fungus wiiicli accompanies

this disease lielongs to the family of Myxo-
mycetes, fungus consisting of a protoplasmic
mass, the plasmodium, which changes in-
cessantly in shape and which moves after
the style of the lower organisms, the amceba.

POLYPORA. — These receptacle fungi form
projecting lamelliB either fleshy or ligneous
in the form of a bracket or a horse-shoe
attached laterally by their r)ase in the in-
terior of which their mycelium is spread.
Polypores attack fruit trees. They cause
white rot especially of the wood of the oak.
They rapidly damage the wood of the trees
which they invade. The infection occur.?-
especially in the spots where there are
fissures which have been proiluced by frost,
where there are sections of cut branches, in
short all wounds are open roads to the pene-
tration of these dangerous fungi.

PoLYPORUS iGNiARius (false tinder
fungus). — -As widespread as P. sulphnreus,
it preferably attacks very old oaks and there
causes white rot, but it also shows itself on
the beech, the poplar, the hornbeam, the
willow, aud on fruit trees. Infection is pro-
pagated by passing from the alburnum and
the liber to the heart-wood. The latter is
rapidly consumed, dissolved, anil reduced
into a whitish friable mass which is separ
ated from healthy wooil by a brown border.
The receptacles are ligneous caps, rust-
brown and greyish colour ; flocked on the
upper surface they rise one above the other.

PoLYPORUS SOLPHURBUS (heart wood rot).
— -This widespread fungus especially attack.s
the oak, the walnut, the pear-tree, and the
poplar. Where it fructifies yellow sulphur-
ous hoods appear rising one above another.

PoLYSTiGMA RUBRDM (plum-leaf blister).
—In the spring the leaves attacked by this
fungus are covered on the two faces by red
spots corresponding to small receptacles of
spores formed on the mycelium which de-
velops in the nriddle of the parenchyma.
By developing between the cells of the
tissues, this mycelium separates the cells
from one another and disorganizes the
tissues that cause the exhaustion and
weakening of the tree. The dead leaves
contain peritheca, which produce spores in
February or March. Tliese spores placed on
a leaf of the plum-tree germinate iu a few
hours, and their germination tube perforates
the epidermis to penetrate into the paren-
chyma of the leaf.

Potato Disease. Phi/tophthora infeM-
ans. — The fungus which is the cause of this
disease attacks the leaves, the stems, aud
the tubers of the jiotato. The disease ap-
pears first on the leaves and the stems where
it shows as lirowu spots which end by entirely
covering tliem. In wet weather it spreads
rapidly and may then destroy the plant.
The disease develo))s likewise in tlu; tubers
where it shows itself by brown sjjots and by
an alteration of the adjacent tissue. The
infection of tlu! tubers is not always induced
l)y the mycelium of the aerial i)art of the
plant, the latter only penetrating rarely
down the stems into the tubers. The tubers

GLOSSARY.

401

are infected by the eonulia which are de-
tached from the leaves an<l which are en-
trained on the roots by rain water. The
mycelium develops in the interior of the
organs attacked and gives off conidiophora
on the exterior of those on the under surface
of the leaves. The coniilia which readily
become detached are summer spores which
may develop immediately, either by emit-
ting a germinative tube or in forming mobile
zoospores which fix themselves and soon
produce the disease. The Plii/hqihthora
may pass the winter in the tubers. The
PhytophtJwra is not propagated by means
of oospores from one year to another like
Peronospora. It passes the winter in a
hardy manner in the interior of the diseased
tubers. In spring it penetrates the nascent
shoots of these tubers. Such shoots remain
sickly if they are much infested by the
mycelium and sometimes have not the
strength to pierce the soil. On the some-
what vigorous shoots the mycelium forms
conidiophora early, the couidia of which
spread this dreadful disease over the whole
field.

Potato Scab. — This is due to the growth
of an aerobic bacteria in the living tissues
of the circumference of the tubers. Under
the irritating influence of their development
the cells grow in an abnormal fashion below
the point of attack and form a thick crust
which greatly depreciates the market value
of the potato.

PsiLA KOS.B (carrot-fly). — ^The larva of
this small fly, of not more than 4-5 milli-
metres, is black with yellow head and legs.
It dwells in the carrot and there bores holes
which cause the root to rot. The larvne turn
into grubs in the soil ; there are two genera-
tions a year.

PsYLLA. — Hemiptera, distinguished from
the plant lice by the arrangement of their
legs which enables them to jump ; besides
they do not present asexual and sexual
generations, alternating the one with the
other ; they are all sexual.

PSYLLA OF THE PbAR. Psjjlla Piri. —

This Psylla as well as Psylla piricnJa, which
are only to be distinguished from one another
by their dififerent colour, cause great ravages
on pears. The Psylla appears towards the
end of May after ha\ing passed the adult
state in the anfractuosities of the bark.
After coupling, the female lays its eggs on
the leaves and young branches, which then
appear as if dusted with yellow. The
apterous larva? which hatch in a few days
pierce and suck the parenchyma of the leaves
and the young liranches ; the latter especi-
ally bend and perish.

Pyralides. — The Pyralides are micro-
lepidoptera of larger size than the tortricides
and tinea ; their wings are of a triangular
form, the antennoa long and pectinateil.
The grubs though small cause consiileralile
damage.

PYRAMS op the ArPLE-TREE. fkirpo-
capsa pomtmella {apple-worm, codlhi moth).
— Moth of ^-1 centimetre long, ashy-grey

wiugsi striped crosswifie with snialh- dark
sinuous lines, with bronze reflex lunta-e and
marked at tha extremity with a. browu.,spot
encircled by a gilded yellow line, i . -After
fecundation the female lays its eggs one per
fruit on the epidermis of the ncw-forme"d
fruit and on the. suvvouniling leaves. In
about eight days the newly hatched -small
caterpillar penetrates into the interior of the
apple. The fruit then becomes wormy.
There ai'e two swarms a year. The cater-
pillar of the second swarm issues from the
fruit when the latter is I'ipe and passes the
winter for the great part under the bark of
the fruit tree whei'e it spins a cocoon. In
the spring it changes into chrysalis. .

Pyralis of the Plo.m. Otipocapsafime-
brana (wormy plums, plum worms).— Small
butteriiy, 7 millimeti-es long, blackish with
some spots and lines of a greyish-blue. In
July the female lays its eggs on the still
green plum. As soou as hatched the cater-
pillars penetrate into the fruit and remain
there until maturity. Same habits as the
preceding.

Pyralis of the Vine.— Tortrix, 1 centi-
metre long, of a more or less gilt yellow.
The butterfly flies in the end of June ; the
female lays 100-200 eggs on the upper
surface of the leaves forming a sort of
greenish-yellow plate. The eggs hatch in
the end of August. The caterpillars hiber-
nate between the fissures of the props and
under the bark in a small case of white silk
which they spin. In the following May
they quit their cocoons and gnaw the young
buds ; they agglomerate the small nascent
leaves with silk thread thus preventing the
buds from expanding ; moreover they en-
circle the small grapes with a silky envelope
inside which they shelter. The caterpillars,
reach .3 centimetres long, are green with
very small whitish tubers ; the head as well
as the first ring are black.

Rot. Rhizi c^iwia.- Parasitic fungi which
develop on plant roots, penetrate into their-
interior, an(i kill them. Their vegetative
system is highly developed and enables them
to pass in the soil from one root to another.
Selerotes, sorts of tubers, enable them to live
a latent life when outside conditions are un-
favoiu-able to their development.

Rot of the Heart of the Beet. Pleo-
spiira putrefaciens. — The rot of. the heart
of the beet may be produced by several
fungi. That which is the most ordinary
cause is the Peronospora Schachtii, which
directly attacks the small leaves of the heart
and covers them with a lilac flocked surface.
The Sj}harrdhi tabijica causes indirectly the
rot of the heart in passing from the petioles
of the largest leaves to the heart itself. In
both cases the heart leaves which are dead
are covered with a greenish- black coating.

Rot or Moist Gangrene of the Potato.
-This disease is a complete disorganization
of the plant which is attributed to the action
of the Bacillus Amylobacter (Kramer) and
according to American specialists to the ac-
tion of Oospora Scabies (Thaxt).

26

402 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Rot — White, Palb, Livid. Conio-
thyrium JJiplodiella.— This fungus is a
parasite of the giape, which may in certain
cases do considerable damage, as occurred in
1886 in Ija Vendee, in 1887 in Le Gard, and
in L'Herault in Upper Italy and Switzer-
land. The Coniothyrium do not attack the
grapes in the same way as the (Juignardia.
Whilst the latter attacks isolated grapes in
an irregular manner leaving the stalk un-
altered, the former invades the stalk of the
grape shoot and the sheath of the grapes.
The latter change colour, become livid brown,
and soften, and then wither, turning an
earthy colour. On the skin of the dead
grapes there form small globular conceptacles
which give them a shagreen appearance.
Often it is the peduncle alone which is dis-
organized which causes the almost ripe grapes
to fall. The mycelium develops in the par-
enchyma of the grape stalks attacked and
spreads thence into the skin of the grapes
where it forms, when that is withered,
picynides like black rot. These picynides
are up to now the only organs of reproduc-
tion known ; their spores appear to preserve
their germinative faculty all the winter and
even up to the following summer, and can
thus transmit the disease from one year to
another. These spores do not appear to at-
tack the leaves, as the disease is unknown on
the grapes. Generally the germination tube
of the spores penetrates into the stalks of
the grapes by wounds produced by large
hail-stones or by insects. This fungus ap-
pears to be more particularly a wound
parasite which thus renders it especially
dangerous alter violent storms or an inva-
sion of cochylis.

Rust, Linear or Common. Puccinia
graminis. — This rust attacks wheat, barley,
oats, a host of common grasses, such as
meadow grass, couch grass, dactyla, agrostis,
cauche ?, flouve ?, fo.xtails, brizes ?, fleoles ?,
festuca, etc. It is the most dangerous rust of
cereals. It particularly attacks the leaves,
their sheaths, and the stalks (straw). The
uredo form appears at the end of the month
•of June. They are elongated pustules which
let an orange-coloured powder escape. At
the latter en<l of the season these spores
form black pustules, puccinia, the black rust
of farmers, in which the teleutospores are
developed. These spores enut in the follow-
ing spring a promycelium of which the spor-
idia only germinate. On the barberry, tliey
produce it'ciiliuiu, the spores of which infect
■ cereals ami produce the uredo form.

Rust ok Bekt. Ununyirs BftK.—'This
rust is autoic, which means that the whole
cycle of its evolution is gone through on the
same jjlant. All the forms of fructification
may therefore be formed on the beet. It
attai.-ks the beet in summer, and may, when
it assumes a great develoi)ment, liamage the
leaves, and cause a perceptible (Icircasc in
crop. The ureilospores form small, very
numerous ovoid or rouiwl pustules, which
pierce the epidermis and let a yellowish-
brown powder escape.

Rust of Cereals. Puccinia. — At lea.st
three different species of rust are to be seen
on grain crops. They are uredinai which
are termed heteroic because during their
cycle of evolution they must live on nurse
plants of different orders. Uredinae of this
genus have, therefore, multiple methods of
fructification which generally succeed each
other in the course of tiie year in a fixed
order. In the early spring the spermagones
and the iecidium appear ; in the course of
summer the uredo ; finally in autumn the
teleutospores. The uredo or red rust form
is the form of dissemination of the fungus
during the germination of the cereal, the
black rust or puccinia assures the trans-
mission of the disease from year to year.
The mycelium of these fungi grows ex-
clusively in the interior of the organs of the
plant attacked. The spores are generally
formed under the epidermis of the nurse
plant through rupture of which it is spread
outside. The mycelium is most often local-
ized and only occupies a limited point of the
tissues which it destroys. The orange spots
seen on plants each correspond to a special
hotbed of infection. At these spots the
mycelium forms felted masses which destroy
the living tissues. The spores which form
under the epidermis become detached as
soon as ripe, and may germinate immedi-
ately if they fall in a drop of water in warm
weather. The germinating tube, crawling
on the surface of a leaf, for example, pene-
trates into a stomata and extends into the
tissue, reproducing in eight days an analogous
spot to that from which it escaped. A rust
spot on a cereal may thus contaminate the
whole field in a few weeks. At the back-
end of the season orange rust is no longer
formed, but black rust or puccinia, a pustule
of a black colour. The spores formed in the
puccinia differ from the uredospores in the
fact that they do not become detached on
ripening from the end of their support and
do not germinate until after several months'
rest in the following spring. These spores
are termed teleutospores. The teleutospores
do not produce a germinative tube capable
of penetrating by a stomata into the nurse
plant and of developing there. The teleuto-
spores give rise to a promycelium, the
growth of which is limited and on which
spores form the sporidia. As they develop
they may pierce the epidermis of the nurse
plant which is always a different species.
The mycelium has a form of fructification
which differs from that of the uredos and
the puccinia ; the ))ustules appear in the
spring and are of two sorts, the ici'idium,
forming on the lower surface of the leaves,
and the spermagones, forming on the upper
surface of the leaves. These two forms spring
from the saiu(! iriycelium ; spores are formed
in these two receptacles. The spores formed
in the iccidium are capable of reproducing
the rust disease on a new support which is
always a cereal. Those formed in the sper-
magones are called spermatia. Their r61e is
not yet finally establisheil.

GLOSSARY.

403

RD8TofComposit.e. Piicrinia Tanaceti,
Puccinia ccjitjMsitarum. — This rust, injuri-
ous to composita?, especially to Artemisia
dracunculus, Absinthium ft viilijare, Tana-
cetum indgare, to the j^-owth of ehrysanthe-
munis, is characterized by small round, brown
and black cushions which spot the leaves.

Rust of Gooseberkibs. Puccin ia liibis.
— The rust causes great damage by attacking
gooseberry leaves and fruit.

Rdst of the Leaves of the Mulberry.
Cylindrusporium Mori.- — The leaves of the
mulberry have, from the first of spring,
brown, pale, irregular spots, limited by the
veins. On these spots pustules are to be
seen, in which conidia form, by which this
fungus multiplies all the year round. The
peritheea appear ou the leaves, which fall at
the end of tiie season. The ilisease does not
cause great damage ; but it renders the leaves
unfit for feeding silk-worms.

Rust of 0.\ts. Puccinia Curonatu. —
This rust is peculiar to oats. It has, like
the preceding rusts, the uredo and puccinia
forms on oats, but on the contrary the
aecidium form on different plants of the
Rhamnaceae, particularly buck-thorn and
black alder.

The rust of cereals often cause a con-
siderable decreased yield when the tempera-
ture is warm and tlie air humid ; the great
number of pustules exhaust the plant and
prevent the normal formation of grains, living
at the expense of the substances accumulated
for that purpose. Garola found that 1000
grains of wheat from the rusted plant only
weighed 22'2 grammes, whilst the same
number of grains from healthy plants
weighed 42'8-65'0 grammes. According to
Gregoire the decreased yield is 8 per cent
to 2'-i per cent for straw, and '21 per cent to
47 per cent for grain.

Rust, Spotted. Puccinia Rabiyo vera.
— The uredo pustules formed on the leaves
and the stems of cereals are more oval than
those of the linear species. It is the rust of
wheat, although it also attacks ri/e and barley.
On wheat it develops abundantly in the
spikelets, on the glumes where it can cause
great damage by stopping the growth of the
grain. Spotteil rust does not fructify like
linear rust but as uredo and puccinia on the
cereal, and produces aei.-idium on the plants
of the family of Boraginse : vipers' bugloss,
bugloss, officinal borage, comfrey, lycopods
of the fields, officinal cynoglossum (hound's
tongue).

Rust ok Spruce Needles. Chrysmnyxa
Abies. — The young needles attacked in the |
course of summer, from mid-June to mid-
July, turn yellow where the fungus is local-
ized. In autumn there are formed on these
yellow parts projecting elongated golden-
yellow cushions, consisting of a mass of
teleutospores. In the spring the epidermis
splits above these cushions, the spores issue,
give off a promycelium charged with sporidia
and reproduce the dust on the new shoots.

Rust of Stone-fruit Trees. Puccinia
Pruni. — This rust attacks the plum-tree,

j apricot-tree, almond-tree, and peach-tree.
It is recognized by its cinnamon-brown tufts
i consisting of uredospores on the under sur-
face of the leaves anrl the rapid alteration of
■ tlie latter. The trees attacked lose their

leaves prematurely.
j Rust (Vesicular) of the Bark of the
Pi.ne. Periderrnium Pini, J'ine Cluster
\ Cups. — In May bladders or whitish mem-
branous sacs, wliicli split to let the aecidium
spores which they contain, and which form an
orange dust, escape, are seen to appear on the
pines, chiefly at the foot of the stem of the
young plants, or on the branches of adult
plants. The mycelium extends between the
bark and the liber, and sinks into the wood
through the medullary rays. Tlie mycelium
is perennial and forms new receptacles each
year until the branch is exhausted and dead.
Under the influence of this fungus, the
starch in the cells is converted into turpen-
tine, which flows through the holes in the
dead bark, and resinifies on the surface of
the diseased parts. On the young pines
the mycelium soon invades the whole stem,
and kills the tree, thus producing great
ravages in young plantations. The adult
trees resist longer, bat, owing to the great
damage to the I'ark, and the cambium layer,
they languish, gradually lose their branches,
and top and finally die. This uredineae is
heteroic ; its uredo and teleuto forms are
found, according to Klebahn, on the swallow-
wort ( Vinceto.r.icum officinale) under the
name of Crunartium ascepliadeum (Fries).
Rust (Vesicular) of Pine Needles.
Peridermium oblamjisj/o-ium. — This rust is
similar to the preceding, but it is localized
in the needles. It develops aecides in such
large numbers that the trees become per-
fectly yellow, but the damages caused to
the trees are less perceptible than those
caused by the preceding fungus.

Rust, White, of Crucifer.e. Cystopus
Candidas. Rust, White, of C'omposit.b.
Cystopus Cubicus. — The hyph* of the
mycelium of these diseases glide between
the cells of the nurse plant and there sink
their suckers. The conidiophora form white
pustules which are found indifferently on
the surface of the leaves, stems, flowers, and
fruit, for the fungus invades all the plant
and causes it to undergo very curious de-
formations. These diseases can only be
transmitted when their spwres succeed in
introducing themselves through the stomata
into the cotyleiions of the young plant. It
is then that they invade the \ laut during
its growth and infect all the organs. The
first of these diseases is injurious to water-
cress, to turnips, and to cabbages. The
second to viper-grass, and to salsifis.

Rusts. Uredina'. — The uredinae are
parasitic fungi the mycelium of which grows
exclusively in the interior of the body of
green plants. Their spores are generally
formeil under the epidermis of the nurse
plant, whence it spreads outwards through
the tearing of the epidermis which occurs.
It is from the orange-brown colour of their

404 IXSECTICIDES, FUNGICIDES, AND WEED KILLEES.

spores that the uredinffi are termed rusts. \
Generally the mycelium of the uredin£e is |
localized' aud only occupies a limited point
of the. tissue of the nurse plant. It does
not .traverse it throughout to fructify in a i
determined point like the mycelium of bunt j
and the greater number of f;'«^(7rt(/o. Where
the germiuative tube of a spore enters the |
tissue of a plant, it ramifies and produces its
fructitications. The leaves charged with ,
rust spots are soon exhausted, they turn
yellow ^nd die prematurely. The evolution
of rust varies much, a description of the im-'
portant rusts seems therefore desirable.

Saperda carcharias (shagreen saperda).
— Among the longicorn coleoptera injurious
to wood, the saperda- is one of tlie most
common. It is '27 millimetres in length,
brownish-yellow colour ; the elytra carry
black projecting points which impart to
them a shagreen appearance. The larva of
the saperda is one of the most dangerous to
young poplar plantations. Tlie eggs are
arranged in fissures of the bark, the larv£e
perforate these and bore ascending holes in
the wood. The metamorphosis lasts two
years and nymphosis occurs near the exit
hole. The trunks of certain poplars, less
than twenty years old, are sometimes riddled
with holes to such a pitch, .that a slight
gale suffices to cause them to fall.

Saperda populnea (sapei-da of the pop-
lar).—This saperda is only 10-12 millimetres
in length ; it is blackish-brown ; the elytra
are spotted with small yellow dots. The
female lays its eggs in the branches of the
poplar. The larva penetrates into the
branch, ami there bores a long hole. Its pre-
sence is indicatei.l by a circular swelling of the
bark. The branches attacked show swellings,
termed galls. The larval life last two years.

ScOLYTES.— The scolytes are small-sized
coleoptera, which the number and nature of
their depredations render very injurious to
forest ami fruit trees. They bore holes of
various shapes, for the most part between
the bark and the wood, in which the female
lays its eggs. The larvae bore seeomlary
holes, which sometimes peneti'ate directly
and deeply into the wood. They preferably
attack sickly trees, because the circulation of
the sap is not so intense as to hinder their
mining work. Their presence is indicated
1)y the leaves yellowing without a fixed
reason. The scolytes greatly resemble the
hylesines ; they present the peculiar char-
acter of having an ovoid heail, covered with
a tuft of hair, the anteiinw, ternnnated by a
highly developed swelling, aud tlie abdomen
truncated at its upper and posterior part.

SCOI-VTU.S ()!•• THE PHIM. Scnfi/flis I'nUll.

■ — It ravages ])ltims and ajjide-trees. The
larvre bore- their holes in the liber and there
pass the winter in the nymph state. The

nsects hatidi in Ajiril and lay their eggs in
May. The folia.ge of the invaded trees is
scanty, their growth is sickly, and they do
not yield fruits.

SCOLYTDS (Roc;03E). Erriiptiif/aaier reiju-

osu.s. — It preferably attacks small branclies

and limbs. The perforated parts of the tree
turn- yellow and die. Plum-trees are especi-
ally chosen by it.

Septoria. — These are parasitic fungi of
the leaves. They produce withered and dis-
coloured spots on which there are formed,
below the ep dermis, picnydes, which have
pierced through the mouth of a hole through
which the spores escape. There are more
than 500 species of SejAnria, but the small
spots which they produce on the leaves are,
in general, without serious consequence.

Septoria tritici, Septoria graminum.
— In the spring the leaves of autumn wheat
are ^.'overed with spots ; this fungus exhausts
the leaves which wither and die prematurely.

Sesi^. — Butterflies, which have a portion
of the wings transparent, which causes them
to resemble wasps and flies. Tlieir cater-
pillai's are miners and live in the trunks of
trees where they produce the same depre-
dations as tlie caterpillars of the-Cossus and
the larvse of the Saperdse.

Sesia apifor.mjs. Twchilium upiformi.
— Butterfly resembling a wasp. It shows
itself in June. The female lays its eggs at
the base of white-wood trees (poplar, birch,
willow, aspen). The caterpillars bore holes,
which may traverse the tree from one part
to another, and even reach the roots. The
metamorphosis lasts two j'ears.

Sesia myopiformis. — The caterpillar
lives in the interior of the trunk of the
pear-tree aud the apple-tree.

SiLPHs. — Silphs preferably attack de-
composing animal matter ; but certain species
form an exception and attack cultivated
plants. ,

SiLPHAOPACA(beetcarriou beetle). Silpha
atrata (black sylpli). — Coleopterse, I centi-
metre long, entirely blackish-brown, the
corselet is highly developed, and in the form
of a shield. The larva attains li centimetres
in length ; it is black and reseml:)les a large
wood louse. These insects cause serious
damage to beet fields. Their invasion of
Franc'e dates trom 1846. They have spread
in such numbers as to lay waste the depart-
ments in the North of France. The larva
of great voracity attacks beet leaves ; it hides
all day in the soil, and only issues forth at
niglit to commit its depredations. It appears
in May to nyraphose in the soil in June.

Si'H/ERlACEiE. — The sphivriacece comprise
a great number of saprophytic fungi, or
parasites ; they have small, black, and not
very visible peritheea. These fungi often
cause serious damage to cultivated plants.
Sph/ERELLa pr.agaui.e (spots of the
leaves of the strawberry). — The leaves at-
tacked by this fungus are covered with
purple-brown rounded spots, separate or
contiguous, which appear, on their upper
face. Tliey incTease rapidly in size, witlier
in the middle, and are finally jjierced right
througliv On these spots all the conidia are
formed, which readily germinate on the
strawberry leaves. Wlien it bleeds with
intensity it may stop the growtli of the
fruit auil kill the plant.

GLOSSARY.

405

Sph.euella Tulassei (black of cereals).
— In moist weather cereals Ijecome covered
with black spots. The fungus cladosporiuni,
which produces this disease, shows itself very
commonly on the dead parts of very different
plants, and it lives generally as a saprophyte.
The black of cereals may cause-rather great
damage, the leaves witl(Wiun<5>'t>irn grey,
the stalks die without prrtdue^ng ears.

TexthrEdo (sa-wi-tiyi 'Ok- THE' Tdunip.
AthiilM >Spi)l'n-ii!jii-:^'~-^lShe' lopx'a of this
saw-tiy 'attav'ks' ^tlie tarnip; it -"gnaws the
parenehyrta t*f the leaves. Two annual
generations^— June and Septeinbeiv .

Tetraxvohus TELARics (TeA' spider).—
A red, polyphagous acarus, it att!\cks the
most xliverse plaiits, chiefly trees, 'haricots,
peas, clover, piimpl^ins; beets,- hemp, hops,
roses, limes, chestnuts, wiUOT\-s, anil fruit
trees. It produces the same symptoms on
all these plants. ' Tiie leaves', prematurely
discolotired, become copper' yellow or reel,
and eventually witlier,' to fall- before the
end of sunihier. The under surfaces of these
leavers are coverai with "a Vety fine light-
tissue and wliitt; pellicles, itt -the midst of
which the red acarus moves.- -If the trees
be examined, the limes for {jxample," deprived
in this way of their leaves, the branches are
found covered W'ith a silky tiss'^ie containing
thousands of acari. These acari are accus-
tomed to quit the leaves ill. atttumn, and to
hide themselves round the buds to pass the
winter ; they even often attack these, and
deform them up to the niomeut of their
exodu-s in the month of May, towards the
young leaves produced by the healthy bnds.
The constant irritatioji, prod-'iced on the
leaf by the rostrum of these acari, excite the
cells, which multiply abnormally and pro-
duce characteristic deformations, brown
ru.st, erinoses, galls, etc., forming propitious
shelters for tliese acari. They produce on
kitchen garden plants and on fruit trees the
disease known- by gardeuf?rs as (/rise and the
lii'i/ (lisji.-ie of the vine. •

Thuips of Cereals. Thrips Cerealium.~
— This hemiptera of 2 millimetres is a
dangerous ''parasite. The larvse attack the
ears of wheat, rye, and' barley, wdiere tliey
suck the newly formed grains, and stop their
development. The adults, crawling always
on the most tender leaves of the plant, suck
them iind wither them. Its damages, it
appears, are not confined to cereals ; the
thrips likewise attacks strawberries, peas, etc.
Tinea. — Small iuoths distinguished by
long antenn;p, narrow and pointed at thrir ex-
tremities, and by large fringes which line the
periphery of their vvin^s; especially the lower
wings. The caterpillars, known under the
vulgar name of nutes, commit serious havoc.
Tinea of Fi.ou.:. Asupiiijariitcilis. — -
Butterfly of •24-25 millimetres from tip to
tip. Upper wings yellow in the miildle,
and brown at the summit and the base.
The lower wings gi'ey, witti two bright lines.
Tile caterpillars live in flour and bran.

Tinea ok Grain; Tinea iji-aui'lla. — The
tinea of gi-ain is a butterfly a little larger
than the preceding. It causes damage dur-

ing the first fortnight of August. The female
seeks the wheat gi'anaries, there to lay its
eggs on the grain. The caterpillars, known
as the white-worm of wheat, hatch in eight
to ten days and attack several grains at. a
time, uniting them by a tissue, in the shelter
of which they gnaw them on the outside.

TiNGIS PIRI. Tiger i<f the I'ear-lree. —
This brown flat hendptera, 3 millimetres in
length, appears in June. LarvK, gi-ubs, and
•adults live as one family on the lower sur-
face of the leaf or the young shoots, and
riddle them with their pricks. The young
'shoots wither and the leaves brown. The
tiger preferably attacks pear-trees grown on
an espalier, and its depredations are most
terrible in August and September.

TiPULA OLERACEA (meadow tipula). TlPU-
LA PHATENSis (garden tipula). — The tipulte
resemble large gnats with long legs ; the
body is grey, highly elongated. They are 2
.centimetres long. The.y may be seen flying
■ above meadows in summer. These large ^
mosquitos lay then- eggs in Jime in the soil.'
The larvfB, which hatch in eight days, live
imdergrouud, where they attack the radicles
of kitchen garden plants and ornamental
plants; They are particularly injurious to
meadows, to grass plots, and to cereals, of
which they not only attack the roots, but
also the leaves in the spring (Eitzema Bos).

TylenC.hus tritici ("ear -cockles,"
"purples," "false ergot," galls-of wheat,,
e-il -worms of wdieat). — ^'I'he eel-woi-m of wheat
is a very staall filiform worm with a smooth
tegument which twists its body like an eel,
hence the name given to it ; length 3 milli-
metres. -The ears attacked in place of
ordinai-y grain have small, rounded, blackish
grains like smutty, grains. If a section be
made of one of these grains there will be
seen under the hard, thick .shell a white
farinaceous mass consisting- of- thousands of
small anguillulides in a dormant state of life
and perfectly immobile. A little moisture
suHices to awake them, which invariably
comes when the smutty grain is sown.
These eel-worms may preserve their vitality
for two and a half years in the grain. Once
.they issue from their- home they instal
-themselves on the young plants, asi-ending
as the stem rises ; reaching the \onng ears
they penetrate the still milky grains where
the females depo.sit their progeny. These
srriall microscopic worms cause the disease
known as earcockles. In the spring when the
young stems of spring wheat are infested
with eels the leaves ai-e gofi'ered and folded,
the plant, in.stead of growing iu height,
tillers.

Uuocystes cepul.e (smut of tlie onion).—
Tliis smut causes considerable havoc in
America. It has been observed in France
l)y Cornu. It attacks the bull)s of the
onion when very young and kills tlu-m. Its
presence is indicated by obsi-urc spots on the
leaves of the young onion, whilst in germina-
tion the leaves split longitudinally and show
a withered tissue covered with Vilack dust.
The smutty s])ots afterwards extend on the
bulb and invade it at its base.

406 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

USTILAGO AND TiLLETIA.— (1) Ufttilaqo

smut which destroys all the parts of the
flowers, and only leaves of tlie ears of
barley and the clusters of oats the axis and
the hulls. (2) The stinking smut or bunt of
wheat TUletui, which only attacks the grain
which it replaces byits organs of reproduction.
USTIL.AGO. — The mycelium of the UstU-
agiiieix live in the interiir of the plant ; it
gives rise to numerous fertile branches, in-
side which the spores are formed, which de-
tached form a black pow.ler. These are the
dormant spores. V stila fo Maydis (maize
smut) may directly invaile the young tissues
of the adult plant. None of the other
Ustilaglneir can enter the nurse plant except
at the birth of the latter. The mycelium
which develops forthwith in the tissues of
the seedling on the level of the ground, ex-
tends gradually into the whole plant without
perceptibly affecting the growth of the latter.
It afterwards tra\ erses the whole nurse plant,
and whilst life is gradually extinguished in
the lower parts of the plant it concentrate.s
itself towards the top and arrives at maturity
in the ears at the end of the period of growth
of the plant. The black spores which are
formed, and which spread themselves on the
adult plants, do not cause the disease. These
spores generally pass the winter and may
remain, according to circumstances, several
years in the latent state. The following
spring they germinate (if the conditions are
favourable); they can germinate in a few
hours ; there is first formed a promycelium
which produces sporiiiia. The latter if de-
tached from the promycelium are capable of
reproducing the disease if they encounter a
young nurse plant. They tlien penetrate it
at the base of the stem or the beginning of
the root. Amongst the Ustilaga these same
winter spores, if they are brought into a
nutritive medium in a soil manured with
farmyard dung, and especially with purin,
may multiply like leaven without producing
promycelium or sporides, and live as sapro-
phytes until they meet with the seedling
cereal. The spores of TiUetiu are enclosed
at harvest time in the interior of the rusted
grain and are almost all carried to the grauary
where they are spreail over the corn during
threshing. It is not so with the spores of
Ustil(i(j(i. The spores of this fungus being
open to the air at the time of the flowering
of the cereals, the greater part falls on the
.soil or is carried away by the wind. At
harvest time the seeds oidy bear few spores
on tlieir surface. See Bunt, p. 38S.

UsTii.AOo Maydis (smut of maize). — This
smut attacks tlie fructitied maize, not only
in tlie floral bracts where it forms large,
unshapely smutty tumours on the pauicles
of the male flowers, liut also on the stems
tliemselves where the amassed spores form
bulky excrescencc^s.

UsTii.Aco Panici Miuacei (smut of
millet).- -It invades all the \y.\xU of the flower
of millet and damages them. The s])ores are
formeil in the inflorescences when they are
yet enveloped in the sheatli of the top leaf.

Vesperus Xatarti. — Greyish longicorn
coleoptera, 2 centimetres in length. The
female of this coleoptera lays 200-.W0 eggs
in the beginning of wiuter under the bark
of vine stocks. The small larvae issue in the
end of April, bury themselves in the soil,
and gnaw the roots of the vine. They take
three years to reach inatuii'^y, and attain
tlie size of the white-worm. This insect is
spread chiefly over the north of Spain, and in
France, in the departments of the Pyrenees-
Orientales and Au<le, Its ravages have been
reported, especially in the communes of
Banyule, Port Vemlres, and Collioure, where
it annually ' destroys from 50-60 hectares
(125-150 acres I of vines.

Woolly Aphis. Schizoneum Innigera. —
This aphis has great analogy with the phyl-
loxera ; it lives like tlie latter, as well on the
roots as on the aerial part of the plant, but
it prefers the branches to the roots. It
especially attacks the apple-tree. From the
winter egg issue, especially in the months of
November and December, parthenogenetic
individuals which yield numerous gemma-
tions of similar individuals. From 18
May to 12 September Kess'.er observed
ten generations ; in summer there was
a swarm every fortnight. The aphis hatched
in August have wings and produce eggs from
which issue sexual individuals deprived of
wings and of suckers. After sexual inter-
course the female lays a single egg. The
woo'ly aphis, distinguished by the thick down
covering them, are grouped in colonies on
the branches and on the edge of the wounds
and sink their dart, as shown by Prillieux, as
far as the cambium. The activity of this
part of the wood being soon increased, it
gives rise to abnormal tissue, to noilosities
which split deeply and end in forming
cancers, which cause the rot of the branch.
Kessler and Goethe have observed this dis-
ease on apple-tree and pear-tree roots, on
which it forms the same nodosities. The
diseased condition of tlie trees is known by
their perishing, aiicl their leaves which rapidly
turn yellow and fall during summer. The
woolly aphis descend on the roots to a depth
of 65 centimetres (26 inches).

Zabrds Gibbl'S (zalirus of cereals).
French : Caruhe Ixissu. — Black coleoptera,
1^ centimetres long, with an accentuated
prominence of the throat. It attacks corn
crojis in June in the night and devours the
milky juice. The larvae are as injurious as
the perfect inse(d-s ; they are yellow, with
cross plates ; they remain hidden in the
day in the burrows dug in the soil, and issue
at night to devour the wheat in the blade,
tiiey commit tlieir depredations in autiiniu
as well as in sjiriiig for they take two to
three years to nietaiiior])liose.

Zeu/eha /Kscui.i (wood leopard moth). —
The cater))illar of this bonibyx has analogous
habits to tliose of the Uossit.^ lii/ziifn'iyla
('/.(•.) ; it attacks chestnut-trees, (dms, limes,
l)irches, oaks, apple-trees, ])ear-trei's, ana
others ; its life as a caterjiillar also Lasts three
years.

INDEX.

Abies balsamea, 69.

Abraxas grossulariata, L. (magpie moth),

121, 363, 374, 377, 383.
Absinth, essence of, 315.
Absolute alcohol, 129, 313.

— diseases, 1.

— parasites, 3.

Absorption of copper salts by plants, 2U<i-».
Acacia, kermes of, 306.
Acari plant lice), 5, 15, 31. 53, 102, 117,

132, 152, 276, 3j6, 343, 368, 375, 376,
383!

— (snreen lice), 375.
Acarus telarius (red spider). See Tetrany-

clius telarius.

of gooseberry (Briobia Ribis), 31, oo-j.

Acetate of copper, 241. 281-2.

(basic), 279-81.

iron, 173.

_ — lead (sugar of lead), 19^ 217.

Aceto-arsenite of copper (emerald green,
Paris green), lU-H, 95, 241, 260, 270-6.

Acetylene, 157, 308-10.

— lamps as insect traps, 8.

Acids: preparation, properties, and use ol,
as insecticides, fungicides, and weed-
killers-
Acid, acetic, 323-4.

— arsenic, 97.
_ arsenious, 18, 94-7, 109.

Z carboli!;' 14, 162, 170, 305, 337, 338, 343.
354-8.

— hydrochloric, 88-9.

— hydrocyanic (prussic), 9, 11, 12, 14, ^6

130-3.

— hypochlorous, 153.

— nitric, 90-1.

— oleic, 307.

— o.\alic, 188.

— phenoisulphonic, 167.

— phosphoric, 92.

— picric, 358.

— prussic. See Acid, Hydrocyanic.

— sulphocarbolic, 167.

— sulphuric, 17, 31, 82-8, 133. 32/, 332.

— sulphurous, 78-S2, 201.

— sulphvdric, 11, 41-2.
Acridides, 95-6, 109, 116, 340, 383
Acridium miLTatoriuin, 9a-b, 109, lib, d4U.
— peregrinuni, 95-6, 109, 116. 340.
Acrostalaginus albus, 370.
Actinonema rosie (rose rust), 150.
Aderhold's bouillie, 169.

Adhesion of bouiUie bordelaise, 2.;8, 245.

Adiantus, 132.

Adjuvant causes of disease, 1, 15.

Adoxus Vitis, 67, 383.

Aecidium of barberry, 48.

— clematidis (clematis disease), 52.

— Euglerianum, 52.

— grossularioe, 246.
jEcidospores, 166.
Aerial parasites, 64.

— treatment of plants, 12, 64.
Aerobic bacteria of potato scab, 114.

Age of plant, and effect of bunt and smut,.

32.
Agrilus Sinuatus, 164, 383.
Agriotes (elaterides, click beetles), 58, b/-y,
95, 106, 108, 120, 211, 298, 301, 307, 330,

— lineat'us, 67-8, 95, 106, 120, 146, 153, 225,

275, 345, 383.

— obscurus, 68, 95, 383.
1 — sputator, 68, 95, 383.

Agrotis (Noctua), 384.

— corticea, 76. , , ^ *v,\ -n

— exclamationis (hart and dart moth), iv,.

90, 334. _

— nigricans, 70. ■, ^ c, -n oa

— seeetum common dart moth), 24, (U, 90,

120 275-6, 303, 336, 353, 382, 384.

— tritica, 70, 384.

— valligera (Trachea piniperda, Piue noctua),.

25, 397.

— vestigialis, 70. , •„• ooa
Albumen, binder m copper bouillies, 284.

— coagulation of, 129, 202, 204, 207.

— precipitation of, 14. ^
Albuminous bouillie, 285.
Alcohol, absolute, 129, 313.

— amv ic 164, 297, 314, 328-), 332-3.

_ efe 313: 328, 3-^9, 332, 343, 347. 371-2.

3"76-7, 378-9, 381.
_ methylic, 313, 331.

— phenylic, 354. See Carbolic Acid.
Alcoholic solutions, 10.

— — of soap, 9.
Alcohols, 312 rf .sef/., 351.
Aldehyde, formic (formalin), 35, 21U. <3io

et seq.
Alder, galeruca of, 129.
Aleyrodes citri, 351.
AlgK, 206-7, 208.

— gi-een, 289.
Alkalies, caustic, 10, 98, 99, 112.

— carbonated. 101. 110, 121.
Allium, 194.
AUorhina Nitida, 301.

(407)

408 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Almoud-tree, diseases of : —

Cojhineal, 136, 389.

Grapholitha, 146, 394.

Rust of kernel fruit trees, 246, 266.

Spots of leaf, shot-liole fungus, 254, 267.
Aloes, 148, 332.

Alsace Lorraine phylloxera regulations, 71.
Alteration of cellular tissue by disease, 1.

— of organs of plants, 1.

Alteruaria Hrassica; (melon leaf scorch), 115,

253, 284, 384.
— ■ Solaui (potato leaf curl), 253, 384.
Altise of cereals ( Flaltica vittula), 302.

— of crucifers (Haltica oleracea, Phyllotreta

nemorum, P. nigripes, P. siuuata, P.
iindulata), (garden altise, kitchen garden
altise), 302, 340, 373.

— of haricots and peas (Haltica ruflpes),

302, 3S4.

— of plum (Haltica chalybea), 274.

— of potato (Psylloides a'ffinis), 302, 384.

— of vine (vine flea, Pucerotte), 52, 146, 156,

260, 274, 373, 379, 384.
Altises (earth lice, halticineie), 52, 122, 146,

195, 260,1274, 332, 340, 345, 357, 3^2,

373, 379-80, 384.
Alucite of cereals- (Sitotraga cereallela),: 31,

70, 82.
Alum, K2S04Alo(S04)324HoO, 163-4, -327.

— action on fungi, 163.

inserts, 163-4.

— plants, 163.

— chrome, K2S04Cr2(SO.i);,24H20, 163.

— preparation, 163.

— properties, 163.
Alumed plaster of Paris, 157.
Alumina, occurrence, 164.

— properties, 164.

• — .silicate of (clav, china clav), 164.

— sulphate of, 162, 194.

— nse, 164.
Alunite, 117.

AmarautiLs blitum, 132. 136, 289.
Ammonia, NHg, 98-9, 310, 352.

— action of, on various plants, 98.
on germination, 98.

— {ireparation, 98.

— properties, 98.

— u.se, 98-9, 352.

Anunoiiiacal gas and liquor, as insecticide

and weed-killer, 99.
Amnn:iiate of cioper (solution of cupric

liydratc in XS of ammonia), 315. See

Eau Celeste.
AniniDnium l)ichromate, 188.

— carbonate, 101.

— — preparation, 101.

propertit^s, 101.

US', lUl, 241.

— ch]ori(le, 327.

— chrom.ite, 188.

— suljihate, 100-1.

— • — manufa-ture, 100.

— — jH-oin-rtics, 100.
usM, 100-1, 265.

— sulphide, 99-100.

— - - j)n-])aration, 99.

— — Ijropcrties, 99.

— — iwe, 91M00.

— sulplio-yanide (thio ■yanatc), 100.

Ammonium sulphocyanide preparation, 100.

properties, 100.

use, 100.

Amyl alcohol, important role of, in insecti-
cides, 164, 297, 328-9, 332-3.
Amylo carbol, 314.
Ananas (cane sugar disease), 339.
Anbury (finger and toe), 122, 144, 400.
Anguillulides (nematodes). See Eel-worms, i
Animal oil (.' Dippel's), 313.

— parasites, 2 et seq.
Ardsopterix ses miliaria, 138.
Annual submersion, 30.

Anobium panicum (maize weevil), 68, 384.
Anomala V'^itis (green vine beetle), 67, 391.
Anoxia Villosa, 340.
Antagonistic symbioses, 3, 4.
Authomvia antiqua, 308, 346, 385.

— beta>,'308.

— bras.sija, 306, 384-5.

— ceparum, 308, 385.

— furcata, 308, 385.

— of bulb of onion (onion flv), 308, 346,

385

— of cabbage, 306, 384, 385.
Anthonomes, 80, 146, 186, 273, 302, 343,.

385.
■ — ■ of the apple-tree (apple blossom weevil),
80, 146, 186, 273, 343, -356, -385.

— of the cherry, 80, 146, 186, 273, 385.

— of the cotton-tree (cotton weevil), 273.

— of the pear-tree, 80, 146, 186, 385.

— of the strawberry, 302.
Authracno<is of the haricot (Colletotriehum

Limlemutliianum), 258, -267, 385.
— ■ of the melon (Colletotriehum oligochsetum,

lagenarium), 258, 385.
— • of tlie tomftto (Glososporium phomoides),

255.
— • of the vine (grape rot) (Glososporium am-

pelophagum, Sphaceloma ampelopha^a),

51, 86-7, 143, 169, 185, 225.
Authracogenic parasites, 113.
Antibiosis, 3.
.■\uticryptogamic substances, composition, 4,

8, 16, 22 ; Crouzel's composition, 103,

148, 345.

— solutions, 16.

" Autimildioidium," composition of, 216.
" Autiuonuiue," action on plants, 358.
— ■ — on insects, 368.

— composition, 367 ; use, 368.
Antiphylloxeric submer.sion, 25.
" Antivermin," 314.

Ants, 38, 93, 129, 153, 293, 326, 330, 316,

380.
Aphides (naked plant lice), 76, 117, 152, 187,

196, 260, 305, 308, 326, 331, 342, 345,

346, 360, 361, 365, 367, 374, 376, 381,

38.')-6.
" Aphidin," 314.
Aphis. See Aphiiles.

— gossyjui, 351, 385-6.

— oxyeautha^, 117, 152, 385-6.

— papaveri.s (po])i)y ajjhis), 331, 385-6.

— persiciB (peacli apliis), 76, 152, 376, 381.

— rosi« (rosf apliis), 7ti, 331, 385-6.

— • woolly (Schiz)iu'uralanigera). See Woolly

Ajjliis.
.^[jhroplior.i sj)uniaria, 363, 3S6.

INDEX.

409

Apple-tree, diseases of: —

Authonomus pomorum, 80, 1-16, 186, 273,

343, 385.
Arniillaria Mellea, 58, 156, 386.
Bitter rot, 116, 142, 255, 267, 394.
Black rot (Splioeropsis nialorum), 250.
Bombyx mouaca, 367, 368, 387.
Browuiug of leaves, 53, 375.
Capricorn, small, 69, 388.
Cochineals (scale inse ts), 40, 136, 182, 187,

306, 342-3. 393.
Codlin moth, 53, 129, 1-34, 151, 196, 275,

H46, 380, 401.
Eriuosis. 53, 170, 260, 347, 381, 392.
Fu-sicladium deiitriticum (apple scab), 116,

151, 159, 182, 209, 225, 255, 266, 273, -393.
Gloeosporium frutigenmu (bitter rot),

116, 142, 255, 267, 394.
Hyduiim, 151, 395.
Hvpoiioiiieuta Maliuella (small ermiue

moth), 80, 116, 138, 2-59-60, 275, 304,

341. .357, 374, -395.
LygiLS, 304.
Nectria ditissima. 151, 185, 250, 324, -339,

366. 397.

Phalenv of the apple-tree (Emiomos siib-
signaria), 138, 146, 196, 276, 340, 352,

367. 389.

San .Jose louse. 107, 122, 136, 147, 152,

296, 306, 327, 332, 354, 390.
Sesia apiformis, 64, 70, 336, 379, 404.
Apricot -tree, diseases of : — •

Eriocampa, 53, 116, 146, 260, 275, 331,

352, 374, 377, 380, 392.
Fumasine (black .smut of, capnodium), 30,

51,^7, 150, 191,260,393.
Grapholita, 146, 341.
Magpie moth (Abraxus grossulariata), 121,

363, 374, 377, 3S3.
Rust of stoue fruit trees, 246, 266, 403.
Apterous insects, 16.
Apt sulphur, 50.

Arboriculture ami forestry, 16, 24-5, 80, 89,
145, 158, 178-82, 204, '211, 214, 247, 2.59,
306, 335, 346, 357, 367-8, 387. 392, 395,
403, 404, 406.
Armillaria Mellea, tree root rot, 58, 156, 3.S6.
Arseniate of lead, 195-6, 363.
preparation, 195.

— — — properties, 195.

use, 196, 363.

■ potash,

*' Arsenic." See Arsenious Acid.

Arsenic acid (preparation, properties, use), 97.

Arsenious acid, 94, 271.

— sulphide, 94.

Arssnite of copper (Scheele's gi-eeu), 10, 260,

276.
preparation and properties, 276.

— — • — u.se, 276-7.

— of lead, 197.
preparation and properties, 197.

— of lime, 158-9, 270.

— preparation and properties, 158.

use, 158-9, 270.

— of soda, 108-9, 271.
Arseiiiuretted hydrogen, 93-4.

— — ])reparation, 93.

properties, 93.

use, 93-4.

Arthropodes, toxic action of camphor

vapour on, 352.
Artichoke, disea.ses of: —

Ca-ssida uebulosa (tortoise beetle), 156, 260,

274, 388.
xMildew (lettuce), 244, 266, 398.
Artificial clouds, 20.

— cultures, 160.

— percussion of air, 20.
Ar\icola (field mice), 92.
Asafnetida, 164.
Ash-leaf mildew, 392.

Asopia farinalis (tinea of flour), 70, 82.
Asparagus, diseases of : —

Crioceris, 52, 122, 146, 196, 273, 302, 330,
345,373,390.

Noctua exclamationia, 70, 96, 384.

Rhizoctiuia, 320, 401.

Rust, 69.
Aspergillus niger, 198, 208.
Asphyxia of insects by paint, 327.

— of the vine by submersion, 29.

— of vermin by benzene and cement, 336.
Asphyxiants, 9. '
Aspidiotus (cochineals), 40, 82, 107, 122,

132, 1.36, 1.52, 3J6, 332, -390.

— aurantii, 77, 136, 152, 292, 351, 390.

— citriinis, -351, 390.

— limonis, 343, 390.

— ostreaformis, 40, 132, 136, 306, 390. '

— perniciosus, 107, 122, 136, 147, 152, 296,

.306, 327, 332, 351, 390.

— uv;«, 351, 390.

Asteroma radiosum (rust of rose), 150, 284.

Asthenic diseases, 2.

Atlialia spinarum (turnip saw-fly), 380,

386.
Athous. See Elaterides, Wire-worms.
— ■ h senior rhoidalis, 386.

— hirtus, 386.
— ■ niger, 386.

Atomaria linearis, 161-2, -326, 345, 357.
Auramine, 370. See Methyl Violet.
Avena Sativa. See Oats.

B

Bacillus amvlobacter (potato rot), 47-8,

401.
• — butyricus, 84.

— mj'coides, 84.

— radicola, 4.

— solanacearum (potato scab), 47-8, 87, 89,

112, 114, 143, 182, 237, 291, 301, 319,

320, 356, 401.
— • tabificans (Jaundice of beet leaves), 291.
Bacteria, 114. ,

— • and soil exhaustion, 19.

— of .soil, 4, 57.

Bacteriorliiza of Hiltner and Strolimer, 4.
Bacterium gummis (gum disease of olive), 80,
114, 394.

— mori (bacterium disea-se of the mul-

berry), 182, 396.
Balbiani's ointment, 338 (344, formula), 345,

347.
Barljary fig, pri.kly pear bouillie, 214.
Barberry and cyclic development of rust of

wheat, 17. "
B.ire fallow as insecticidal agent, 5, 19, 58.

410 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Barium carbonate, 139.

— chloride (preparation, properties, use),

138-9.

— sulphate, 139.

— sulphocarbonate, 139.
Barley, diseases of: — ■

Browning (Helminthosporium gramineum),

115, 224.

Disinfection of seed-barley, 33-4, 85,221,
290.

Grasshoppers, 99, 120, 304, 389.

Rust, 40, 85, 114, 142-3, 170, 2J0, 204-11,
2^1, 269, 320-3, 402-4.

Smut, 31-7, 85, 111, 2--^!, 290, 406.

Thrips, 308, 333, 367, 405.
Batates edulis (sweet potato), 47.
Bean, diseases of : —

Bruchus, 37, 68, 309, 388.

Mildew, 114.

Noctua gamma, 157, 357.
Beech (Fagus), action of HCl gas on, 89.

— (Fagus), diseases of ;■ —
Agrilus sinuatus, 164, 383.

Canker, 151, 184-5, 250, 324, 339, 366, 369.
Liparis mouaca, 367, 368, 387.
Lucanus cervus, 69, 396.

— sj'mbiosis with fungus, 4.

Beet carrion beetle, 274, 324, 330, 345.

— diseases of :• —

Agrotis segetura, 24, 70, 96, 120, 275-6,

303, 3.36, 353, 382, 384.
Atomaria linearis, 161-2, 326, 345, 357.
Carrion beetle (Silpha opaca), 274, 324,

330, 345.
Cassida nebulosa, 156, 274, 3S8.
Cockchafer, 24, 42, 65, 67, 134, 146, 157,

297, 301, 310, 335, 345, 356, 390.
Disinfection of seed, 84, 225, 291, 355,

356.
Flv, 308, 385.
Heterodera (Nematode), 42, 58, 65, 99,

108, 119, 144, 187, 307, 395.
Leaf-stalk disease, 24, 36, 84, 143, 355,

399.
Mildew, 243-4, 398.
Plusia gamma, 157, 357, 397.
Rhizoetinia, 36, 144, 156, 185, 356, 401.
Rot of heart, 24, 36, 185, 399.
Rust, 246, 402.
Spot of leaves, 258, 389.
Weevil, 307-8, -335-6, 391.
Bellows for sulphurating, 47.
Benzene, 132, 305, 334-7.

— emulsioiLS, 335.
Bicarbonate of copper, 287.

Bichloride of mercury, 8, 144, 166, 204, 289-

293.
Bichromate of potash, 189.
Hinders (glue, etc.) in bouillies, 285.
Bird-lime, 16, 351-2.
Birds, 195, 343, 377, 381.

— granivorous, 195, 377, 381.
Bisulphide of carlion, 55-7.

— of mercury, 273.
Bisulphite of lime, 157.

— of magnesia, 162.

Bitterrotof fruit (Oloeosporiuni frutigenum),

116, 142, 2.55, 267, 391.
Black currant, disea.se of :—

Magpie moth, 121, 363, 374, 377, 383.

Black rot of grapes, 49, 90, 103, 143, 191, 224.
250-3, 266, 281, 284, 292, 309, 366.
386.

— smut of fruit trees. See Capnodium.
Blatta Orientalis (cockroach), 93.
Blissus leucopteris, 331.

Blue, Prussian : —
Preparation, 188.
Properties, 18-*.
Use, 188.

— vitriol (copper sulphate, which see) : —
Preparation, 201.

Properties, 201-2.

Use, 202-26, 241, 242, 290, 292, 293, 339.
Boiler, hot-water, for vine scalding, illus-
trated, 49.
Bombyx chrvsorrhea (brown-tailed moth),-
21, 22, 80, 260, 386.

— dispar, 196, 297, 303, 340, 348, 363, 873,

387.

— monaca (Nonne), -367, 368, 387.

— mori silkworm, 144, 210, 291, 312, .355.

— neustria, 260, .367-8, 387.

— pini, 25, 146, 340-1, 387.

— processionea, 340, 387.

BoraginiE and cyclic development of parasitic

fungi, 17.
Borago officinalis, 124, 132, 289.
Borates (preparation, properties, and use

of) :-
Borate of copper, 268.

— of iron, 188.

— of manganese, 193.

— of soda, 97, 109, 166.

— of zinc, 166.

Borax. See Borate of Soda.

Bordeaux "mixture". See Bouillie Borde-

laise.
Borers. See Bostrichus.
Boric acid. See Acid, Boric.
Bostrich of the tig (Tomicus ficus), 145.

— of the mulberry (Tomicus Mori), 145.
Bostrichus, 387.

— dispar, Tomicus dispar, Bostrichus taxe-

sini, 145, 164, 357.

— Tvpographicus (typographer bark beetle),

"387.
Botrytis chierea (grey rot of vine), 143, 156,
157, 162, 163, 194, 259, 284, 320, -387.

— Douglasii (conifer disease), 192.
Bouillie, albuminous, 285, 286.

— arsenical, 153, 260, 274.

— copper bicarbonate, 277.

carbonate, 287.

ammoniacal, 287.

— corrosive sublimate, 291.

— galipot, 214, 288.

— milk, 286.

— saccharate of copper, 287.

— turpeutine, 288.

— verdigris, 281.

Bouillie bordelaise (Bordeaux mixture), (pre-
paration, ])roperties, and use), 144,
226-60, 321.

arsenical, 274.

celeste, 279.

— — — (single powder), 217.

— — hyposulphited, 103.

lactated, 286.

modirted, 286.

INDEX.

411

Bouillie bordel;iise, })etrol-soap, 288.

— — powders for, 214-17.

— — saccliarated, 287.

— • — soapy, 286-8.
sulphurated, 50.

Bouillie bourguiguoune (Burguii<ly "mix-
ture"), 110-11,277-9.
— - — albuminous, 285-6.

— — gelatinous, 286.

saccliarated, 284.

• soapy, 286-8.

— cadmium hydrate, 167.

— containing nitrobenzene, 354.
Bouillies, cupric, 6, 17.

— cu pro-arsenical, 260, 274, 300.
— ■ cuproinsecticide, 379.

— cuprouicotinic, 372.

— cupro-resiuous, 288.

— ferric, 168-9.

— gelatinous, 287.

— lactocupric, 285-6.

— lime arsenite, 158.

— mercurial, 291-2.

— oily, 288.

— permanganate, 192.

— Ferret's, 282-4.

— pyrethrum, 307.

— resinous, 288, 347-52.

— saccharine, 282-4, 287.

— tar, 339. 341-3.

— various, 284 et seq.
Bramble, spots of leaf, 254.
Brassica chinensis, 194.
Breadcrumbs, 293.

Briobia ribis (gooseberry acarus), 31.
Brome grass, smut of, 36.
Bromide of copper, 203.
Bromus arven.sis, 36.

Browu-tail moth. See Bombyx chry.sorrhea.
Browning ot leaves of pear-tree and apple-
tree. See Phyllocoptes Schlechtendali.

— of leaves of vme (Plasmodiophora cali-

fornica), 237, 388.

— of vine (.see Plasmodiophora), 340, 388.
Bruchidese, 31.

Bruchus, 388.

— granarius, 68.

— pisi, 37, 68, 309.

— rutimaus, 68.

Brunissure de I'orge (black mould of cereals),

115, 224.
Brush, applying insecticides by, 131.
Brussels sprouts, relative disease, 1.
Bryobia ribis, 31.
Bugs : —

Cabbage bug (Eurydema oleracea, Pen-

tatoma oleracea, Strachia oleracea),

Vegetable garden bug, 40, 304, 342,

357, 367, 398.

Cotton plant bug (O.xycarenus hyalini-

peunis), 304.
Fruit tree bug, 374.
Graminacese bug (Blissis leucopteris),

331.
Meadow bug, 304.

Orchid bug (Phytocoris militaris), 377.
Potato bug (Halticus Uheleri), 304, 395.
Bullock's blood, 164.

Bunt, stinking smut of wheat (see Tilletia
caries), 190, 388.

Bunt, stinking smut of oats. See Tilletia.
Burgumly pitch (spruce oleo-resin), 351.
Burn-cow. See Agrilus sinuatus.
Butter, 293.
— of zinc, 165.

Cabbage, disea.ses of :—

Anbury, tinger and toe, 122, 144, 400.

Disease (Cystopus candidus), 48, 403.

Entomoscelis adonidis, 275.

Fly, 306.

Hadeua [Mamestra Brassicie], 276, 395.

Heterodera [nematodes], 42, 58, 65, 99,

119, 144, 187. 192, 307, 384, 395.
Margantia histrionica (Pentatoma ornata,
Eurydema oleracea), (cabbage bug), 40,
304, 342, 357, 367, 398.
Pierides, 38, 107, 276, 303, 330, 340, 400.
Weevil (Ceutorhyuchus sulcicollis), 307,
335,391.
Cabbages and arsenical spraying, 272.
Cadmium sulphate (preparation, properties,

and use of), 167.
Calandra granaria (wheat weevil), 68, 81,
345, 388.

— oryza (rice weevil), 68, 391.

Calcium, salts of (preparation, properties,
and use of) : —
Calcium arsenite, 158-9.

— bisulphite, 157.

— carbide, 157.

— carbonate, 281.

— caseate as binder in copper bouillies,

286.

— chloride, 152, 200.

— chlorohypochlorite (bleaching powder),

153-4, 200-1.

— hyposulphite, 149.
— • oxalate, 324.

— phosphide, 157-8. 225-6, 308-10.

— sulphate, 154-7, 162, 229, 327.

— sulphide, 148-52.
glycerinated, 151.

— sulphite, 157.
Calendula arvensis, 124.

Calomel (mercurous chloride), 14, 204, 293.
Camphor (preparation, properties, and use),

352.
Canker of beech, 151, 184-5, 250, 324, 339,
366, 369.

— of larch (Dasyscypha Wilkonimi), 185,

391.

— of olive-tree, 114.

— of pear-tree and apple-tree (Nectria ditis-

sima), 151, 184, 250, 324, 339, 366.
— • of vine. See Botrytis Cinerea.
Capnodium (fumagiue, black smut of fruit

trees), 30, 51, 77, 150, 191, 260, 393._^_

— salicinum (Fumago salicina), 30, 51, 77,

150, 191, 260, 390.
Capricorn great (Cerambyx hcros), 69, 388.

— of maple (Cerambyx dilatatus), 69, 388.
Capsules, glycerinated, as media for CS2,

62, 68, 69.
Carbide of calcium, 157, 225-6, 308 10.
Carbiiles. metallic, 157, 225-6, 308-10.

— organic, 294 et seq.

412 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Carbides, terpeuic, 348.
Carbolated tobacco juice, 260.
Carbonates used as insecticides, fungicides,
etc. (preparation and properties of) : —
Carbonate of ammonia, 101.

— of baryta, 138.

• — of calcium, 140.

— of copper, 277.

— of lead, 197.

— of )jotasli, 121.

— of soda, 110-11, 287, 288, 342, 351.
■Carbon derivatives, 294 382.

— disulplude, 5, 17.. 5.5-77, 295, 297,; 337.
action on fungi. 57.

■ — ■ — • — on insects, 56-7.

on parasites, aerial, 64.

— • — capsules, 62, 68, 69.
cropping treatment, 72.

— — extermination, 71-2.

— — • history, 59-60.

influence of, on fertility of soil, 57.

— — preparation, 54.
properties, 54-55.

• — — rules for use of, 72.

vase lined, 61.

use, against cryptogamic disease, 64.

• r — . instruments, 62.

'■ in closed spaces, 63.

• insecticide, as, 65-71.

■ — disulplude, irrigations, 75..

— ■ ~ ■ — in solution, in water, 74-5.

• rodents, to kill, 77.

Carbonic o.xide, 312.
Carbonnat. See Anthracuosis of Vine.
Carex, rush, 121, 176.
Carnallite, 117, 160.

Carpoeapsa funelirana (pvralis of plum), 129,
134, 275, 401.

— pomonella (codlin moth), 53, 129,- 134,

151, 159. 196, 275, 346, 380, 401.
Carpocoris (pentatoma) baccarum (fruit tree

bug), 374.
Carrot, diseases of the : —

Duskv cli-k beetle, 67-8, 95, 383.
Fly, 306, 308, 400.
Weevil, 307-8, 335-6, 391.
■Caseate of copper, 285-6.
•Casein, u.se of, as binder in copper bouillies,

28.5.
Cassida | Haltica] nebulosa, 1.56, 274, 388.

— viridis (Cassida of artichoke), (articholce

tortoise lieetle). 260, 373.
Catechu or cutc;h, 382.
Caterpillar of calilwge, 38, 107, 196 276

303, 330, 340, 400.
Caterpillars, 146, 303, 314, 326, 376.
Cauliflower, 1, 144.
Caustic potash, 350.
Cecidomia of rose (rose-fly), 374, 381.

— of violet (violet-fly), 134, 3-0, 388.
•Celery, disease of : —

Cercospora apii, 52. 258, 3S8-9.
Cellular resistance to insects, 2.

— rottenness, 23.
Cement, Portland, 157.

— Jlonian, •'J^ti.

Cemiostoma Sritf]l;i (pear leaf spots), 70,

388.
■Cerambvx dihitatus (capricorn of niaiile),

69, "388.

Cerambyx heros (great capricorn), 69, 388.
Cercospora angulata (gooseberrv leaf spot),
254, 268, 384.

— apii, 52, 258, 388.

— beticola (beet leaf spots), 258, 388.

— circumcissa (shothole fungus), 267.

— resedie (mignonette leaf spots), 258, 389.
Cereals, copper, per cent in, 205-6.

— diseases of : — ■ ■
Agriotes Imeatus, 67-8, 95, 106, 120, 146,

153, 222-5, 275, 345, 383.
Agrotis segetum, 24, 70, 76, 96, 120,

275-6, 303, 336, 353, 382, 384.
Altise (Haltica vittula), 302. See Altises.
Alucite (Sitotraga cereallela), 31, 70, 82. -
Black mould ( Helminth osporiumgratriiii-
euni), 115,224. -. ■ - -••

— (Sphferella Tulasnei), .36, 405; ' ' ' ■
Bunt (Tilletia), 34, 84, 104, 183, 190; 197,

219, 222, 311, 320
Calandra granaria, 68, 81, .345, 388.
Cockchafer, 67, 390.

Crioceris, 373, 380, 391. ' •

Grasshopper (Jassus Sexnotatus), 99, 120,'

304, 389.
Lucauus cerviis, 69.
Mildew (Ervsiphe), 48, 150, 184, 191, 248,

392.
Ru.st,"36, 48, 114, 165, 170, 189, 190, 193,

197, 200, 223, 269, 324, 402.'
Smut (U-stilago), 32-6, 84,114, 119,183-4,

217-24, 245-6, 290, 292, 316-9, 320-3,

358, 406.
Thrips, 308, 333, 367.
Zabrus gibbus, 273, 406.
"Ceres," proprietai-y fungicide, 115.
Ceroplastes (cochineals), 82, 132.

— fluoridensis, 351.

— rusci, 132.
Cetonia, 389.

— stictiea, 335.

Ceutorhynchus sulcicollis (cabbage weevil),

307, 335, 391.
Chaetocnema tibialis (altise), 275. '

Chalk, 281.
Charseas [Nojtua] yTaminis (antler moth,

grass moth), 303, 366, 368, 397.
Charcoal wood, 339.
Charlock, action of weeil-killers on, 106, 118,

161, 176-7, 200.
Cheimatobia Ijrumata (winter moth, Eves-
ham moth), 138, 146, 276, 340, 352, 367-
389.
Chermes picea (kermes, cochineal of sprnce),

357.
Cherry-tree, at'tion of ammonia gas on, 98.

diseases of : —

Anthonome, SO, 146, 186, 273, 385.

Eriocampa, 380, 392.

Flv (Spilozrapha cerasi), 69-70, 153, 381,

389.
Fusicladium I'crasi (spots of cherrv), 257,

393.
Mildew, 250, 266.
S,i\v-flv, 380.
Smaircapricorn, 69, .388.
Spots of, 257, 258, 389.
('jicstniit-tree, diseases of : —

Cockchafer (Meloloiitha jiipjjoi'astani),
301.

INDEX,

413

Chestnut-tree, diseases of : — cont.
Fuugi and symbiosis, 4.
Leaf spots, 164, lt)7, 170, 188, 255.
Nectria ciunabariua, 151, 185, 250, 324,

339, 366, 397.
Tetranvchus, 40, 53, 132, 152, 333, 347,
405. " I

Zeuzera, 78, 336, 406.
Chicory, disease of :—
Mildew (Peronospora gangliformis), 244,
266, 398.
Chitinous carapace of insects, method of de-
stroying, 1-32.
Chloranthea, 23.

Chlorides, preparation, properties, and uses
as insecticides, etc. , of : —
Chloride of barium, 138.
■ — • of calcium, 152-3.

— of copper, 200.

— of iron, 170.

— of lime (bleachiu? powder), 153.

— of magnesium, 117, 160-1.

— of manganese, 193.

— of mercurv pi-oto salt (calomel), 14, 204.

— of mercury (per), 114-15, 209, 289-93.

— of potassium , 117, 209.

— of silver, 198.

— of sodium, 104.

— of zinc, 165, 209.
Chlorine (preparation, properties and use), 88.
• — water and germination, 217.
Chloroform, 56, 311, -335.
Chlorophyll, 290.
Ch'orosis, 14, 109, 170, 171, 172, 173, 174,

178, 179, 181.

— temporary, 388. .
Choice of disease-resisting species, 20.
Chromates, toxic dose in nutritive solution,

189.
Chroococcus, 165, 208.
Chrysalis or Chrysalides, 2, 16.
Chry.santhemum, diseases of : —
Leaf spots, 254, 404.
Rust of Composite (Puccinia composit-

arum), 246, 403.
Chry.somy.\a abietis, 151, 403.
Chrysomelide of radish (Cochleria, Phsedon

armoracire), 302.
ChrysomeliniB, 302.
Chrysomphalus minor (cochineal of orange),

77, 306.
CicadeUffi, 99, 120, 304, -389.
Cicadella of cereals, 99, 120, 304, 389.

— of potato (Typhlocyba Solani), -304.

— of vine ( Penthima atra), -304.
CitruUus vulgaris, 244.
Cladius pectinicornis [Hylotoma Rosa;], (rose

saw-fly), 377.
Cladosporium carpophilum, 258, 389.

— cucumerinum (cucumber disease), 258-9.

— fulvum (tomato disease), 52, 150,258,268,

389.

— herbarium, 36.
Claviceps purpurea (ergot of rve), 86, 113, 121,

166, 175, 185, 209, 210, 224, 290.

Clematis patens, disease of ( \ Aecidium clema-
tides, ? Aecidium Englerianum, ? Nema-
todes), 52.

Clematitis, disease of, 52.

— black, disease of, 226, 389.

Cleonus .sulcirostris, 275.

Clochai/e, gaseous disinfection of the vine, 9,

12.
Cloclie, 11.
Clover. See Trefoil.
Cnethocampa (bombyx) processionea, 340,

387.
Cnicus arvensis, 355 .
Coal-tar, 337-43.
Cobalt salts as growth stimulants, 18.

— sulphate, preparation, properties, use,
194, 207.

Coccides (cochineals), 37, 40, 42, 76-7, 82,
88, 147, 152, 164, 187, 260, -306, 308,
312, 314, 327, 332, 342, 347, 349, 350-1,
354, 357, 363, 367, 389.

Coccinella [Epilachna globosa], 275.

Coccus [Pulvinaria] \'itis (red cochineal of
vine), 77, 82, 88, 136, 147, 306, 337, 342-3,
375, 390.

Cochineals (Coccides), Aspitliotus, Cero-
plastes, Diaspinte, Diaspines, Diaspis,
Kermes, Lecanium, Plant lice, which
see.

Cocliineal comma, cochineal of apple, which
see.

— of almond-tree (Lecanium amygdali), 136.

— of apple-tree (Aspidiotus ostreaformis,
Diaspis ostreaformis, Mytilaspis pom-
orum, apple-tree mus.sel scale), 40,
136, 182, 187, 306, 342, 343, 390.

— of fig-tree (Ceroplastes rusci), 136.

— of lemon-tree (Dactylopius citri, Lecanium
citri, Kermes of lemon-tree), 42, 136,
342-3, -350-1, .390.

— of olive-tree (Lecanium Oleae), 136, 350-1.
— ■ of orange-tree (Aspidiotus aurantti,

Aspidiotus limoni, Chrysomphalus
minor, Lecanium hesperidum, Mytilas-
pis flavescens, Kermes of orange-tree),
1.36, 152, 292, 306, 343, 389-90.
— ■ of peach-tree (Lecanium nigi'ofasciatum,
Lecanium persicae. Peach kermes), 136,
306, 389-90.

— of pear-tree (Diaspis piricola), 40, 306,
389-90.

— of spruce-tree (Chermes picse, Mindarus
abietinus), 357.

— red, of the vine (Coccus Vitis, Pulvinaria
Vitis), 77, 82, 88, 136, 147, 306, 337,
342-3, 375, -390.

— white, of vine (Dactylopius Vitis), 82, 88,
-343, 389-90.

Cochleria (chrysomelide of radish), 302.
Cochylis of vine (Cocliylis ambignella,

Cochylis roserana, Conchylis ambignella.

Vintage worm), 8, 38-9, 81, 90, 100, 116,
I 129, 187, 191, 211, 260, 281, 288, 297,

-303, -307, -326, 336, 341, 346, 349, 354,

362, -367, 374, 376, 380, 390.
Cockchafer. See Melolontha vulgaris.
Cockroach, 93.

Codlin moth. See Carpocapsa pomonella.
Codoil, -328, 351.

"Coffee pot" for vine scalding, 38-9.
Colaspidema atrum (babotte, barbare, uegril),

145, 345, 390.
Cold water spraying, 30-1.

— — submersion, 2-3-30.
Coleophora, 70.

414 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Coleoptera of granaries, destroying, 81.

Coleus, 132.

Colletotrichum lagenarium, 258, 385.

— Lindemuthianum, 258, 267, 385.

— oligochfetum, 258, 385.
Colocynth, 313.

Colorado beetle (Leptinotarsa decemlineata),

196, 260, 379.
Colza (rape), diseases of ;—
Cabbage weevil, 307, 335, 391.
Heterodera, 42, 58, 65, 99, 108, 119, 144,

187, 192, 3iJ7, 384, 395.
Noctua gamma, 157, 357, 397.

— ploughing in crop of, to disinfect soil,

134.

— oil, 325. 326, 327. 351-2.
Common salt. See Sodium Chloride.
Comjwsitae, diseases of ; —

Hop mildew (Sphajrotheca Castaguei), 38,

51, 115, 392.
Rust, 246, 403.
White rust, 48, 403.
Concentrated copper bouillies as winter

dressings, 17.
Conchylis ambiguella. See Cochylis am-

bignella.
Conidia, 182, 212, 224, 244, 245.
Conidiophores, 13, 47, 113, 115, 224.
Conifer disease (Botrytis Douglasii), 192.
Coniferae, 253.

— symbiosis with fungi, 4.
Coniothyrium diplodiella, 162, 263, 402.
Copper, detection of, in plants, 206.

— percentage of, in plants, 206.

— salts (preparation, properties, and special

uses as insecticides, etc., of): —
Copper acetate, basic, verdigris, 203,

281-2.
normal, 203, 241, 279-81.

— aceto arsenite (emerald green), 196,

27 1-6.

— arsenite, 196, 276.

— bicarbonate, 287.

— borate, 245, 268.

— bouillies. See Bouillie Bordelaise,

" Bordeau.x mixture," and Bouillie
Bourguiguonne, " Burgundy mix-
ture " ; Bouillie Bordelaise celeste,
and Bouillies, various.

— — (concentrated), as winter dressings,

17.

— bromide, 203.

— carbonate, 205, 277-9, 286.

— caseate, 285, 286.

— chloride, 200, 203.

— ferr(Kvanide, 203, 269.

— hydrate, 142, 226-60, 264.

— najjlitholate, 369.

— nitrate, 200, 203, 205.

— organic salts, solutions of, in injection,

treatment of plants, 14, 162.

— oxychloride, 201.

— phosphate, 268.

— .saccharate, 283.

— sulphate, 14, 35-6, 84, 108, 142, 1.52,

162, 183, 185, 186, 192, 103, 199,
200-1, 203, 205, 226, 227-69, 277-9,
282-8, 290, 338, 339, 341, 343, 352.

— sulphide, 42, 199, 200, 248.

Copper, sulphite, 201.

• and sulphur, incompatibility of,

248-9.

— soaps (cupric, oleate, stearate, etc.),

286-8.

— toxicology of, 201 et seq.

— turnings, use in making eau celeste, 2
Copperas, blue. See Copper Sulphate.

— green. See Iron Sulphate.

— white. See Zinc Sulphate.

Coral spot disease. See Nectria ditissiraa.
Corrosive sublimate, 8, 144, 166, 204, 289-

93. 297, 319.
Corylus. See Hazel.
Coryneum Beyerincki (leaf spots of kernel

fruit trees), 254, 324, 394.
Cosmopterix, 70.
Cossus ligniperda, 64, 70, 297, 336, 357, 363,

390.
Cotton-seed, action of naphthalene on ger-
mination, 344.

— tree, disease of : —
Anthouome, 273.

Cow-dung, 164, 336.
Creolin, Artmann's, 361.

— Jeyes', 360.

— Nava, 362

— Pearson's, 361.
Creosote (wood tar), 337, 362.
Cresol, 359-60.

Cress, disease of : —
White rust of crucifers (Cystopus candidus),
48, 403.
Cresylol, 359-60.
Crioceris of grain, 373, 380, 391.

— of asparagus. See Asparagus, diseases

of.
Crows and carbolated tar and petroleum,

treatment of seed-corn, 343.
Crucifers, diseases of : —
Altise, 302, 340, 373, 379-80, 384.
Bugs, 40, 304, 342, 357, 367, 398.
Mildew (Ervsiphe communis). 48, 150, 184,

191, 246, 392.
Pierides, 38. 107, 260, 276, 303, 330, 340,

400.
White ru.st, 48, 403.
Cryptogamic parasites, 32.
Cryptonieria japouica, 192.
Cucumber, diseases of: —
Pot (Cladosporium), 258, 389.
Tetranychus, 40, 53, 152, 333, 405.
Cucumus sativus, 244.
Cucurbitaceffi, diseases of: —
Anthracnosis of melon, 258.
Hop mildew, 38, 57, 113, 385.
Mildew, 244.
Cucurbita maxima, 244.
Culex pipiens (eommou gnat), 298.
"Cupreina" (proprietary fungicide), 216.
Cupric bouillie and sulphur, incompatible,

248-50.
Cupro-albumiuous bouillies, 286.
" Cuprocalcite " (proprietary fungicide), 49,

216.
CurculionidciB (weevils), 31, 68, 139, 273,

275, 301-2, 391.
Curdled milk, 76, 164, 300.
Cuscuta (Do<lder), 87, 119, 122,150, 178,211,
391.

INDEX,

415

Cuscuta of flax (C. densiflora), 150, 178,
211, 391.

— of hop and hemp (C. major), 150, 178,

211, 391.

— of lucerne and trefoil (C. minor), 119,

150, 178, 211, 391.
Cyanide of potassium, 12, 1-30, 136.
Cyaniding greenhouses, 133.

— trees, 133.

Cycloconium oleaginum (spots of leaf of olive-
tree), 258, 288.
Cylindrosporium mori, 254, 403.

— padi (fall of plum leaves), 254, 403.
Cypress, kermes of, 306.

Cystopus candidus (white rust of crucifers),
48, 403.

— cubicus (white rust of compositae), 48,

403.

Dactylopius citri (cochineal of lemon-tree),

42, 133, 151, 342-3, 350-1, 390.
— Vitus (cochineal, white, of vine), 82, 88,

342, 343, 389, 390.
Dartrose bacillary gummosis of \'ine, 35, 182,

394.
Dasyscypha Wilkommi, 185, 391.
Dauphiuelle Delphinium (larkspur), 382.
Davallia immune to prussic acid treatment,

132.
De Bary on symbiosis, 3.
Deciduous trees and SOj fumes, 80.
Deer, to prevent intrusion of, 148.
Dematophora necatrix (white rot of vine and
fruit trees), 51, 58, 64, 99, 103, 124, 157.
185, 224, 391.
Derivatives of carbon (carbon compounds used

as insecticides), 294-382.
Destruction by weed-killers of : —
Aerial parasites, 64.
Charlock, 106, 118, 161, 176-7, 200.
Horse tails (equisetum), poisonous, 108,

119, 153.
Mosses, 38, 106, 121, 177-8, 211, 237, 291,

363.
Mustards (wild), 176, 200.
Noxious herbs, 87, 106, 119, 153, 176-9,

200, 211, 291, 338.
Weeds, 87, 106, 119, 153, 176-9, 200, 211,
291, 338.
Dew, toxic, in contact with insecticides, 10.
Diabrotica vittata, 260.
Diantus immune to prussic acid treatment,

132.
Diaspinai (diaspines, diaspis, cochineals), 132,

136, 182, 187, 390.
Diaspis, 82, 1-32, 306, 389, 390.

— fallax, 182, 187, 389, 390.

— ostreaforrais, 1.36, 342, 389, 390.
— • pentagona, 77, 389-90.

— piricola, 40, -306, 390.
Dietetico plant, 15.
Dinitrocresylate of potash, 367.
Diplosis rosiperda (rose-tiy), 374, 395.

— rosivora (rose liv), 380, 395.

— violicola (violet'-tly), 134, 381.
Diptera, 338.

— of the elm (Erymia nitida), 313.

Disease, bacterian, of potato (potato scab), 47,
84, 86-7, 110, 114, 143, 182, 237, 291,
301, 320, 356, 401.

of mulberry, 182, 396.

of wild quince, 237.

— • of beet leaves, petioles (leaf stalks), 24,
36, 84, 143, 225, 355, 399.

— of beets, 225.

— of cabbage, 48, 403.

— of clematis (black), 52, 225-6, 389.

— Californian (browning of vine leaves), 237,

388.

— of conifers (Botrytis Douglasii), 192.

— of cress, white rust of crucifers, 48, 403.

— of cucumbers (Cladosporium cucumeri-

num), 258-9.

— of tlax (Fusarium nov. sp.), 320, 393.

— of gooseberry leaf (Gloeosporium ribis and

Gloeosporium curvatum), 255, 394.

— of gum (Fusiporium limoni), SO, 114, 394.

— of gum of olive-tree and vine-tree, 80,

114, 394.

— of haricots (Phytophthora phaseoli), 114,

242, 281.

— of mushroom (gout of), 366, 368.

— of mushroom (mole disease), 81, 137,

143, 151, 225, 250, 366, 368, 395.

— of orchids (Gloeosporium macropus), 255,

370.

— of plane-tree leaves (Gloeosporium ner-

visequum), 225, 394.

— of plaster of mushrooms (Monilia fimi-

cola), 366.

— of poppy, 225. 370.

— of potato (Phytophora infestans, De

Barv), 86, 89, 90, 110, 119, 121, 143.
166,' 169, 175, 182, 209, 210, 211, 212,
237 et seq , 265, 273, 281, 284, 290,
292, 320, 324, 361.

— of raspberry (Gloeosporium venetum),

255, 394.

— of salsifv, 48, 403.

— of tomato, 52, 116, 150, 212, 242, 258,

268.

— of turnips, 48, 403.

— of vine (red spider), 40, 53, 1-32, 152, 333,

347, 405.

— of walnut, 255, 394.

— ■ of wheat (Ophiobolusgraminus), 143, 186,
397.

— smut (Ustilago), 31 et seq., 83-6, 103, 113-

4, 119. 175. 183-4, 217-24, 245-6, 290-3,
317-23, 358, 406.
Diseases, asthenic, 2.

— bacterian, 47, 106, 319-20.
— ■ sthenic, 2.
Disinfection of : —

Beet seed, 84, 225, 291, 355-6.

Cabbages, 303.

Flower seed, 48, 290, 313.

Graft bearers (vine), 37, 129, 131-3.

Granaries, 63, 68, 311-2, 321-3.

Hothouses, 48-50, 131-6.

Onions, 58. 223, 279, 323.

Ornamental plants, 90, 130, 131-3, 365-6.

— trees, 37, 90, 94, 130, 131-3, 178-9, 192,

298, 343, 365-6.
Plants. 37, 130.

Potatoes, 212, 237, 242, 272, 279, 291, 310,
319-20, 356, 361.

416 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Disinfection of — amt.

Roots, 37, 57, 131-3, 297, 335.

— of trees, 37, 57, 70, 295, 297.
Seed-barley, 33-4, 85, 221, 290.

— millet, .35-6, 210, 223, .322-3.

— oats, 35, S5-6, 113-14, 221-2, 290, 319-

321.

— rye, 86, 209, 290.

— Avheat, 34-5, 85, 113-14, 166, 221-2, 290,

352
Seeds, 32-7, 47-8, 63, 68, 83-8, 95, 106, 109,
113-15, 119, 142, 18.3-4, 190-1, 193, 197,
217, 262 et seq., 292, 311-12, 316, 320,
352, 355, 356, 358.
Soil, 57-9, 179, 298 et seq., 316, 334-5.
' Tomatoes. 242.

— seed, 242, 356.

Trees. See Ornamental Trees.
Trunks of trees, 83, 91, 145, 178, 192, 211,
255, 296, 298-300, 340-3, 363, 366-7, 369.
Tubers, 212, 237, 279, 297, 301, 319-20,

356, 361.
Vines, 36-7, 56 et seq., 64, 90-1, 129, 130,
13.3, 134, 1.35, 136, 137, 139, 297, 299.
See under Phylloxera.
"Disparin" (see Lead Arseniate), 196.
Dothichiza populea, 186.
Dry rot of timber, 88, 362, 396.

Eau celeste (copper hydrate dissolved iu
liquor ammonia), 245, 260-8.

minus ammonium sulphate, 265.

modified, 188, 263.

— — Prillieiix's, 265.
soapy, 286-8.

Eccoptogaster pruui (scolytus of plum), 145,
164, 404.

— regulosus (rugose scolvtus), 145, 164, 340,

404.

— scolytus (elm scolytus), 145, 404.
Eel-worms (Elauhista), 70.

Elater lineatus (striped click beetle). See
Agriotes lineatus.

— obscurus (dusky click beetle). See

Agriotes obscurus.

— segetis (syn. Elater lineatus).

— sputator (spitting click beetle). See

Agi'iotes sputator.
Elaterides (agriotes, wire-worms, click beetles,

yellow-worms). See Agriotes.
Elm, diseases of : —
Cossus, 64, 70, 297, 336, 357, 363, 379, 390.
Diptcra, 313.
Oaleruca, 38, 69, 129, 196, 274, 313, 346,

394.
Scolytus, 145, 404.

Wood leopard moth (Zeuzera esculi), 70,
336, 406.
Emphroctis chrysorrhea, 196.
Emphytus cinctus (rose saw-fly), 377, 395.

— grossularifc (gooseberry saw-liy), 260.
Emulsions, 13, 132.

— amyl alcohol and green vitriol, 187.

— benzene, 335-6.

— crcolin, 359-66.

— CS.j and soaj), 76.

— nitrobeuzenic, 353.

— oil. 300, 328.

Emulsions, petroleum and water,' 298-301,
and fungicides, 298, 301, 350.

— — and insecticides, 300, 350.

and milk, 300, 304.

and milk of lime, 298-9.

and oil, 298-301, S26.

and salt water, 299.

■ and soap, 299, 300, -301.

— soapy, of carbon disnlphide, 64.

— turps and soft soap, 348-9.

Enchlora vitis (gTcen beetle of vine), 67, 391.

Enduits (liird-limes, etc.), 351-2.

Ennonios subsignaria (Phalena of the apple),
138, 146, 196, 276, 341, 352, -367, 389.

Bntomoscelis adonidis, 275, 380, 392.

Entomosporium maculatum (leaf scald of
pear and quince-tree), 164, 167, 169, 170,
187, 199, 201, 257, 267, 268, 277, 279,
281.

— mespili (spots of leaves of pear-tree), 257.
Ephestia Kuehniella (flour tinea), 70, 82,-346,

405.
Ephippigera bitterensis (locust), 52, 340.

— vitium (locust), 52, 340.

Epicea (spruce), action of sulphuric acid fumes
on, 89.

— — diseases of :^

Bombyx monaca, 367, 368, 387.
Bostrichus typogi-aphicus (the typo-
grapher bark beetle), 145, 387.
Cochineal (Cliermes picea and Mindarus

abietiiius), 357.
Cockchafers, 301.
Hylobius abietis, 24, 395.
Rust of needles (Chrysomy.xa abietis), 151,
403.
Epilachna globosa, 275, 392.
Epsom salts, preparation, properties, use, 161.
Equisetum arveuse (meadow horse-tail), 106,

118, 119, 153, 161.

— palustre (poisonous horse-tail), 106, 118,

119, 153, 161.

Ergot of rye (Claviceps purpurea), 86, 113,

121, 166, 185, 210, 224, 290.
Erineum [Phytoptides], 53, 117, 149, 152,

392.
Erinosis [Erineum, Scabs, Phyllerium,
Phytoptides, Taphriua], 53, 117, 149,
152, 276, 301, 307, 375, 377, 381, 392.

— of apple and pear trees ( Erineum i mali-

num, Erineum pirinum, Eviophyes
malinus, Eriopliyes pirinum), 53, 117,
260, 347, 381, 392.

— of gooseberry, 117, 149, 152, 377, 381, 392.

— of pear (pear leaf blister), 53, 117, 260,

347, 381, 392.

— of vine (Eriophyes Vitis, Phytoptus

Vitis), 53, 117, 149, 152, 392.
Eriocampa [Selandria] adumbrat.i (])car-tree
saw-fly), 53, 116, 146, 260, '.^75, 331,
352, 374. 377, 380, 392.

— cerasi, 377.

Eriophyes malinus, 53, 117, 260, 377, 381,
392.

— piri, 53, 117, 260, 377. 381, 392.

— ribis, 117, 149, 377, 381, 392.

— Vitis, 53, 117, 149, 392.

Ermine moth (Hyponomeutamalinella, which

seiO.
Erodium circutariura, 124, 1.32.

INDEX.

417

Erymia nitida (diptera of elm), 313.

Erysiphe communis (mildew of leutils, of
clover, of haricots, lupiues, peas, trefoil),
48, 113, 115, 1.^.0, 184, 191, 248, 392.

ErysipheiB (mildews), 37, 46-7, 48, 115, 149,
150, 191, 392.

Essence of absinth, 316.

— of thyme (thymol), -368.

— of turpentine, 348-9.
Ether (sulphuric), 56, 315.

— petroleum, 294, 307.

Ethyl sulphocarbonate of potassium (xan-

thogenate), 129.
Etiolation, 179.
Etiology, 1.
Eudemis botraua (tortrix of the grape), 288,

392.
Eumolpus Vitis, 67.
Eurydema oleracea (cabbage bug), 40, 304,

■ 342, 357, 367, 398.

— ornatum (decorated bug), 40, 304, 342,

357, 367, 398.
Evergreens, action of HCl gas on, 89.
Exhaustion of soil, 19.
Exoascus deformans (leaf curl of peach), 151,

184, 246, 282, 392.

— pruni (pocket plums and bladder plums),

246, 393.
Extracts, alcoholic, of pyrethra, 378.

— pjTethra, 378.

— — ■ soapy, 378.

Facultative parasites, 2.

Fagus. See Beech-tree.

Fairy ring of carnations, 258.

False tinder fungus (Polvporus igniarius),

151, 339, 400.
Farina, 271.
Fat lime, 140, 200.
Fats, oils and, 315, 324-33.
Ferric chloride, 170.

— ferrocyanide. See Prussian Blue.

— hydroxide (hydrate), preparation, pro-

perties, and use, 168-70.

— sulphate, 187.
Ferrocyanides, preparation, properties, and

use of : —
Ferrocyanide of copper, 269.

— of iron, 188.

— of potassium, 187.

— of zinc, 167.
Ferroso-cupric bouillies, 169.
Ferrous sulphate, green vitriol, 6, 14, 86, 87,

148, 157, 162, 168, 109, 170, 171-87,
188, .336.
Fertilization, arsenical spraying during

flowering, eftect of, on, 272.
Fibrillaria xylothrica, 156.
Fidonia pinica (phalena of pine), 25, 392.
Fig-tree, diseases of : —
Arnulliiria mellea (tree root rot), 58, 156,

386.
Bostric'h, 145, 387.
Cochineal (Ceroplastes ru.sci), 136.
Dematophora necatrix (white root rot), 64,
185, 224, 391.
Finger and toe, 122, 144, 404.

27

Fish oil, 326, 350.

Flax plant, action of weed-killers on, 108, 118.

— — diseases of : — -

Disease, fusarium (Nov. Sp.), 320, 393.

Dodder, 150, 178, 211. 391.

Fusarium (Nov. Sp.), 366, 393.

Noctua gamma, 157.
Flour, tinea of, 70, 82, 405.
Flowering, arsenical spraying during, for-
bidden, 272.
Flower seed, disinfection of, 48, 290, 313.
Fly, beet (Anthomyia Bets), 308, 385.

— cabbage (Brassica), 306, 384-5.

— carrot (Psila Rosje), 306, 308, 400.

— cherry-tree (Spilographia cerasi), 69-70,

153, 381, 389.
saw-riy, 380.

— greenhouse (black thrips), 375.
— • lucerne, 363.

— onion, 308, 346, 365.

— pear-tree saw-fly, 53, 116, 146. 260, 275,

3.31,352,374. 377,380.392.

— radish, 306, 384-5.

— rose, 374, 381-8.

— turnip saw-fly, 380, 386.

Fodder, green, preserving during winter, 107.

Food warehouses, disinfection by gas, 12.

Forest insects and parasites. See Arbori-
culture, etc.

Forests, submersion of, 24-5.

Forma calaminaria, 165.

Formaline, formic aldehyde, formol, disinfec-
tion of seed-corn, etc., by, 35, 245, 316-23.

Formica, 38, 93, 129, 153, 293, 326, .330, 346,
380.

Formol, 8, 210. See Formaline.

Fostitebriihe, 216.

Frondescence, 23.

Frosts, as insecticidal agents, 5, 20.

— late, 148, 156, 181.
Fruit trees, action of SO.j gas on, 80.
_ — sensitive to blue vitriol, 257.
Fumagine (capnodium), smut of fruit trees,

30, 51, 77, 150, 191, 260, 393.

— of the olive-tree, 51, 77, 393.
Fumago salicina, 30, 51, 77, 150, 191, -260.,

39-3.
Fumigation with tobacco, 372.
I Fungi, parasitic, 208.

— saprophytic, 207, 375.
Fungicide powders, 215-16.
Fusarium, -366, 393.

— dianthi, 65, 320.

— Nov. Sp. (flax disease), 320, 39.?.

— Roseum, 292, 370.
Fusel oil (amvl alcohol), 314, 328-9, .3.32-3;
Fusicladium,'ll6, 151, 1.59, 182, 209, 225,

255, 257, 266, 273, 393.

— cerasi, 257, 393.

— dentriticum (apple scab), 116, 151, 159.
209. 225, 255-7, 266, 273, 393.

— pirinum (pear scab), 116, 151, 159, 209,
225, 253, 266, 273. 393.

Fusiporium limoni (gum disease), 80.

G

Gaiacol, 359, 362.

Galeruca of the alder (Galeruca Ahii), 129,
196.

418 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Galeruca of the elm (Galeruca calmariensis,
Galeruca luteola, 38, 69, 129, 196, 274,
313, 346, 394.

Galipot (turpentine oleo re.sin crusted on tree),
214, 288, 348.

Gall mites, 381. See Pliytoptides.

Gangrene of stem of potato, 47, 401.

Gastropacha [Bombvx] neustria, 260, 367 8,
387.

— [Lasiocampia] pini, 25, 146, 340-1, 387.
Gas-work.s, ammoniaeal liquor of, 99.
Gelatine, 10. See Glue.

Gelatinous hydrocarbonate of copper, 216.
Oerminateur giiarante (lead acetate), 197.
Gipsy moth (Bombyx dispar, which see).
Gloeosporium ampelophagum (anthracuosis

of the vine, grape rot), 51, 86-7, 143,

169, 185, 225, 385.

— curvatum (gooseberry leaf disease), 255,

394.

— frutigenum (bitter rot of fruits), 116, 142,

255, 267, 394.

— Juglaudis (walnut leaf disease), 255,

304.

— macropus (orchid disease), 255.

— nervisequum (plane-tree leaf disease),

225, 394.

— phomoides (anthracnosis of tomato), 255.

— ribis (currant leaf spot), 255, 394.

— venetum (raspberry spot), 255, 394.
Glove, Sabat^'s, 91.

Glue, 382.

— in copper bouillies, 245, 284.
Glycerine, 115, 149, 315, 327.
Gooseberrv, diseases of : —

Acarus.'31, 383.

Erinosis, 117, 149, 377, 381, 392.

Gloeosporium ribis, 255, 394.

Leaf spots, 254, 268, 404.

Magpie moth (Abraxas grossulariata), 121,
.363, 374, 377, 383.

Mildew of leaf, 51, 115, 250, 392.

Eust (Puccinia ribis), 246, 403.

Saw-fly (Nematus Ribis), 121, 134,
140, 260, 275, 279, 302, 368, 374, 380,
397.

Tenthredo. See Saw-fly.
'Gracilaria, 70.
Graft bearers, 37, 129, 131-3.
Grafting wax, 349.
Grapholitha Ijotrana, 196, 341.

— Wceberiaua, 146, 341, 394.
Green fodder, preserving, 107.
■Greenhouses : — •

Acari of, 375.
Black fly of, 375.
Disinfection of, 40, 50, 131-6.
<ireen vitriol. See Ferrous sulphate.
Groundsel, 246, 3.36.
Gryllotalpa vulgaris, 25, 93, 98, 146, 298,

307, 326, 330, 346, 384.
Guaicol, 3.39.

Guerinia serratula (kermes of ])inc), 306.
Guignardia Hidwelli (l)lack rotof gi-apes), 90,
103, 143, 191, 224-5, 250-3, 266, 281,
2S4, 292, 309, 366, 386.
Gum, 80, 172, 1S2, 394.

— of ba<'illary, 24, 182, 391.

— of stone fruit trees, 143, 172, 324, 394.
Gustative j)r(>pcrtii's of wine as influenced l)y

insecticide binders, 285.

Gvmnos porangium Sabinae (pine leaf cluster

cups), 246, 394.
Gypsum, 154-7, 172, 271, 281.

H

Hadeua Brassicfe (noctua of cabbage), 276,

395.
Haltiea ampelophaga (altise of vine), 52, 146,
156, 260, 274, 373, 379, 384.

— chalybea (altise of plum), 274, 384.

— nebulosa, Cassida nebulosa( artichoke tor-

toise beetle), 156, 274, 388.

— nemorum, 52, 384.

— oleracea, 302, 340, 373, 384.

— rufipes, 302, 384.

— vittula (altise of cereals), 302, 384.
Halticinea3, 52, 122, 146, 260, 274, 302, 340,

345, 357, 362, 373, 379, 381, 384.
Halticus Uheleri, 304, 395.
Hamster (field mouse), 77.
Hand-picking of Bombycides, 7, 21, 22.
Haricot, diseases of : —

Altise (Haltiea rufipes), 302, 384.

Anthracuosis, 258, 267, 385.

Bruchus, 37, 68, 309, 340, 388.

Disease, 114, 242, 281.

Mildew, 48, 113, 115, 150, 184, 191, -392.

Tetranychus, 40, 53, 132, 152, 333, 405.

Weevil, 363, 373, 391.
Hazel action of HCl gas on, 89.

— (corylus), symbiosis with fungus, 4.
Heat, resistance of fungi to, 31.

■ — ■ — of insects to, 31.
of seeds to, 31.

— wet and hot steeping of seeds, 32-7.
Heliopliobus popularis, 100.
Helminthosporium gramineum (black mould

of cereals), 115, 224.
Hellebore, 300, 302, 377.
Helops lanipes, 345.
Hemp plant, diseases of : —

Dodder, 150, 178, 211, 391.

Noctua gamma, 157, 357, 384.

Orobanche, 211, .397.

Tetranychus, 31, 40, 53, 82, 132, 152, 306,
333, 343, 347, 351, 362.
Herbs, noxious, 338.
Herring oil, 328.
Hespialis humuli, 70.
Hessian fly, 388.

Heterodera radicicola (eel-worm of roots), 58,
65, 108, 301, 307, 395.

— Schachtii, 42, 58, 65, 99, 108, 119, 144,

187, 307, 395.
Heterosporium echinulatum (spots of the

leaves of the poppy), 225, 370.
Hibernia defoliaria, 138, 352.

— marginaria, 138.
Himera pennaria, 138.

Hollow fruit, stems and roots, 23.
Honev, 351.

— dew, 30, 51, 77, 150, 191, 260, 393.
Ho]), diseases of : —

Aphis green-fly (puceron), (IMiorodon

humuli), 139, 351, 370.
Dodder, l.')0, 178, 211, 391.
Mildew (Spherothecacastagnei), 38, .57, 11.5.
Smut (l.lack), (capnodium), 30, 51, 81, 150,

191, 260, 393.
Storing, 81.

INDEX.

419

Hordeuni. See Barley.
Honiiidiuiu, 165, 208.

Horse-tail {E(iuisetuni), action of weed-
killers on, 108, IIM, Itil, 176.
Hot-water iinmersiou of seed agdust insects,
32-6.

— — parasites, 35.

Hv'lnes, 151.

Hyduuiu Scliiedermayri, 151, 39o.

Hydrate of copper. See Bouillie Bordelaise.

— of iron (pero.xide), 168-9.

— of lime, 140.
Hydraulic lime, 157.

Hvdrocarliides [Hydroearl. ms], 291-310, 333-

" 47, 348-9.
Hydrocarboiiate of copper (Eselatiuous), 21b.
Hydrogen, arseniuretted, 93.
— ■" phosphoretted, 93-4.

— sulphuretted, 41-2, 113, 123, 132, 134,

149, 157.

— — in wine, 50.
Hylesines, 145.
Hylesinus ater, 25.

— augustatus, 25.

— cunicularius, 25.

— oliperda. Hi-.

— opacus, 25.

Hylobius abietis (spruce weevil), 24. _
Hylotoma rosoe (rose saw-fly), 342, 378, 380,

395.
Hymenoptera, 338.
Hvpera polygoni (poppy weevil), 68.
— " variabilis (beet weevil), 157, 307, 335.
Hypochlorite of copper, 201.

— of lime, 153.

Hvpomyces peruiciosus (mole disease of
" mushroom), 81, 97, 137, 143, 151, 225,

250, 366, 368, 395.
Hyponomeute of the apple-tree (small ermine

moth, Hyponomeuta Malinella), 80, 116,

138, 259-60, 275, 304, 330, 341, 357,

374, 395.
Hyposulphite of lime, 149, 150.

— of soda (sodium thiosulpliatei, 102, 148.

Icerya purchasi, 351.

Ictaria viridis, 124.

Immersion, hot water, 31-7.

Inciurvaria, 70.

Injection of CSo into soil, 17.^

Injections into tree trunks, 64, 89, 181, 297,

355, 357, 363, 379.
Insecticides, alcoholic : —

" Amylocarbol," 314.

" Antivermin," 314.

"Fichet's," 314.

" Knadoliu," 314, 315.

"Nessler's," 314.

— preparation of, 314.

Soapy (amyl alcohol), 328-9.

— nicotinic, 370-5.
Insects, apterous, 16.

— xyhipha,u'iuis, 14.

Insolubilization of albumen, capacity for, 9.
Instruments in surgical treatment of plants,

6.
Inundation, artificial, 23-31.
Iron salts as growth stimulants 18, 171-4.

Iron salts as growth stimulants, their pre-
paration, properties, and use :• —

Borate of iron, 188.

Ferric hydrate (sesquio.xide), 168-9.

— sulphate Feo3S04, 171.

Ferrocvauide of iron, 188.

Ferrous sulphate (green vitriol), 171 et seq.

Pliosphate of iron, 172-3.
Irrigation versus disinfection, 30.
Irrigations, inseciiciile, 24-30, 75, 76.

— summer, 27-30.

— underground, 28.

— winter, 27-30.
Itch, 102.

Jassus scxnotatus, 99, 120, 304, 389.
Jerusalem artichoke, 19.
Juice, tobacco. See Tobacco.
— — carbolated, 260.
Juniper mildew, 246.

Kainite, 117-20, 144.

Kaolin, 164.

Kernies. See Cochineals.

Kerosene, 306.

Knadolin, 130, 314.

Kieserite, 117-20.

"Kristallazurin," 217.

" Kupferklebekalkuiehl," 216.

Kupferpreparat Gmuud, 217.

■' Kupferschwefelkalk," 216.

" Kupfer soda," 316.

" Kupferzuckerkalkpulver, " 216.

Laboratory, plant at disadvantage in, 11, 18.
Lachuosterna arcuata (red cockchafer), 120,
301.

— fusca (Frohl), 120. _
Lactocupric bouillie, 285.
Lamps, acetylene, 8.
Lantern traps, 8.

Larch-tree, disease of (Dasyscypha Wil-
kommi) : —
Canker of the bark, 185, 391.
C0.SSUS, 64, 70, 297, 336, 357, 363, 390.

— — SOo, action of, on, 80.

— — HCl, action of, on, 89.
Lard, 148, 328, 351.
Larkspur, 382.

Larva form of insects, 16.

Lasiocampia pini(Pine bombyx), 25, 146, 340-

87.
Laughing gas, reduction of soil nitrates to, by

submersion, 29.
Laurel camphor (Laurus camphora), 352.

— rose, disease of : —

Kermes, 332, 367.

— — use of, 382.
Lead acetate, 195-7.

— arseniate, 195-7.

— carbonate, 197.
— hydrate, 197.

420 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Leaf spots, leaf blisters, leaf scalds of :—

Beets, 258, 389.

Celerv, 52, 358, 389.

Cherry-tree, 257-8, 393.

Chestnut-tree, 257.

Chrysanthemum, 254, 404.

Gooseberry, 254, 268, 384.

Oats, 254, 404.

Olive-ti-ee, 2.:.8.

Quince-tree (wild), 257.

Parsley, 254.

Pear-tree (Eutomosporium maculatum, En-
toraosporium Mespili, Morthiera Mespili,
Phyllosticta piriua, Septoria nigerima,
Septoria pirieola), 164, 167, 169, 170,
187, 199, 201, 257, 266, 268, 277, 281.

Poppy, 258, 369.

Raspberry and bramble (Septoria Rubi),
254.

Stone-fruit trees, 237, 393.

Strawberry, 254.

Wheat, 2o4.

— — etc., black, of : —

Almond- tree, "shothole" fungus, 254,

267.
Mignonette, 258, 389.
Pear-tree, 338.
Plum-tree, 250.
Tobacco, 143.
Tomato, 254, 404.
Lecanium (cochineals), 82, 136, 306.

— amA'gdali (cochineal of almond-tree), 136,

389-90.

— citri (cochineal of lemon-tree), 136, 343.

— hesperidum (cochineal of orange-tree),

136, 343, .389-90.

— nigrofasciatum (cochineal of peach-tree),

136, 306.

— olefe (cochineal of oliye-tree), 136, 288,

.351.

— persicas (cochineal of peach-tree), 136,

389-90.
Legumiuosse and microbes, association of, 4.
Lema melanopis (crioceris of cereals), 373,

380, 391.
Lemon-tree (Citronnier), diseases of: —
Cochineal, 42, 136, 342-3, 350-1, 390.
Warts, 268.
Lentils, diseases of : —
Bruchus, 37, 68, 309, 340, 388.
Mildew, 48, 118, 115, 150, 184, 191, 392.
Lepidoptera, 338.
Leporides (hares and rabbits), 164, 298,

327, 343, 368.
Leptinotarsa decemlineata (Colorado beetle),

95, 196, 260, 274, 379, ,395-6.
Lepus cuniculus (rabl>it), 298, 327, 343, 368.

— Eiu-opaius{hare), 298, 327, 343, 368.
Lethrus cephalotes (big-headed lethrus), 67,

396.
Lettuce, diseases of : —
Agriotes sputator (spitting click beetle),

68, 95, 383.
Mildew, 244, 266, 398.
Noctua, 24, 70, 96, 120, 275-6, 303, .336,
353, 382-4.
Leueania unipunctata, 276, 395.
Lichens, 38, 122, 211, 237, 291, 363.
Licopersicuin (touiato), 242.
Ligroin, 291.

Lima bean mildew (Phytophthora phseoli),

242.
Lime as manure, 19, 140.

— bisulphite of, 157.

— hydraulic, 162.

— preparation, properties, and uses of,

as insecticide, fungicide, and manure,
139-48, 339, 344-5.

— soaps, 327, 329.

— ti'ee [Tilia Europea], diseases of: —
Fumagine, black smut, 30, 51, 77, 150,

191, 260, 39.3.
Nectria cinnabarina, 151, 185, 250, 324,

339, 366, 397.
Tetranychus, 40, 53, 132, 152, 333, 347,

405. '

— (tree) looper (Hibernia defoliaria), 138,

352.
Liming of trees, 145.
Limithrips tritici (onion thrips), 357.
Liparis chrysorrhea, brown-tailed moth, 21,

22, SO, 260. 3S6.

— dispar, 196, 297, 303, 340, 348, -363, 373.

387.

— [Bombyx] monaca, 367, 368, 387.
Liquor, cupro-ammouiacal, of Bellot des

MLuieres, 261, 263.

— gas, 99.

— Schweizer's, 261.

Lithium nitrate (stimulant), 208.
Liver, calcareous, 148.

— of sulphur, 113.

Locusta, locustides (grasshoppers), 52, 53,

109, 340.
London purple, 158.
Lophodermium pinastri (pine leaf cast), 258-

9, 396.
Loph-sTus pini, Lophvrus rufus, 25, 146,
302, .368, 374, 395'.

— similis, 146.

Lopus albomarginatus, 308, 336, 380, 395.

— sukatus, 308, 336, 380, 395.
Lucanus cervus (stag beetle), 69, 395.
Lucerne, diseases of : —

Aphrophora spumaria, 363, 386.

Colaspidemater, 145.

Dodder, 87, 119, 122, 150, 178, 211, 391.

Elater sputator, 68, 95, 383.

Epilachna globosa, 275, 392.

Fly (Agromiza nigripes), 363.

Mildew, 48, 113, 115, 150, 184, 191, 248,

392.
Weevil (Phytonomus), 24, 391.
Lupines, 335.

— disease of : —

Mildew, 48, 113, 115, 150. 184, 191, 248,
392.
Lycopersicum, 132.

Lyda (red-heatled ), Lyda erythrocephala, 25,
396.

— campestris (field Lyda), 25, 396.

— nemoralis, 367.

— pratensis (meadow Lyda), 25, 396.
Lygus pratvnsis, 304.

M

Macrodaetylus subspinosus, 264.
Macrosporium solani, 253.
Magdalis, 351.

INDEX.

421

and

Magdalis seuescens, 356.
Magnesia as manure, ItJO.
— salts of, preparation, properties
uses of : —
Magnesium bisulphite, 162.

— carbonate, 281.

— chloride, 160-1.

— silicate (talc soapstoue), 162-3, Alb, -iib.

— sulphate, 161.
Maize diseases of : —

Noctua ijamma, 1.57, 357, 39/.
Smut (Ustdago), 36, 223, 2-45 lOf
Weevil {Anobium pauicum), bs, do4.

Malate of iron, 173. orv n <

Mai di gomma of the olive-tree, 8U, 114
394.

Mai ner'o (bacillary gummosis of vine), 24,
102, 394.

Malva sylvestris, 289.

Mamestra, 196. ^ , , -4.

— of cabbage (Mamestra Brassiea). (white

line brown-eyed moth), 196, 303.
Manganese salts," stimulating action of
"^minute doses of, on plants, 102.

— sulphate, preparation, properties, and

use, 192-3.
Manm-ial action of insecticides :—
Common salt as, 105.
Green vitriol, 171-81.

— — versus potash, 172.
Gypsum, 154-6.
Magnesia, 100.
Potash salts, 118-20.
Quicklime, 140.

Manure, chemical, use of, 19.

discreet use of, 19.

Margantia histrionica (red cabbage bug), 196
Marsh mallow, action of weed-killers on

289.
Mastic in sense of cement, 64, 182, 327.
Meadows : — •

Lyda. 25, 367, 396.

Lygus, 304.

Mosses, 106, 122, 177-8, 211.

Tipula, 69, 108, 137, 405.
Meat preserving in boric acid, 97.
Melolontha fullo, 67, 301, 390.

— hippocastani (horse chestnut, cockchafer),

— vulgaris (cockchafer, may-bug), 24, 42, 65,

146, 157, 297, 301, 338, 345, 346, 390.
Melon, diseases of :■ —
Antliracnosis, 258, 385.
Leaf scorch, 115, 253, 284, 384.
"Nuile,"258, 385.
Menge mallois. See Vesperus Xatarti.
Mercaptan, preparation, properties, and use,

316.
Mercurial ointn)ent, 293.

— spraving, 289.
ISIercurialis annua, weed-killer for, 124, 132,

136.
Mercuric nitrate, 293.

— perchloride, corrosive sublimate, pre-

paration, properties, and v.se as in-
secticide, fungicide, and weed-killer,
204, 206, 208. 289-93.

Mercurous chloride. See Calomel.

Merciury bisulphide, 293.

— in wine, 291.

Mcrcurv, salts of, as gi-owth stimulants, 18.
Meruliiis lacrymans (dry rot of timber), 88,

362, 396."
Metabisulphite of potash, removal ot II3S)

from wine by, 50.
Metamorphosis of insects, 2. ^

Method of disinfecting seed-corn, Jensens,

33.
Mice, 343, 368.
Microbes, 15.
Microbe parasites, 3.
Micro-organisms, 59.
Microsphfera grossularire, ol, llo, iov, zou,

320, 392.
Mildew of beets (Peronospora bchachtu),
243-4, 398.

— of cucumbers (Plasmora cubensis), 244-5.

— of gooseberry, 51, 115, 250, 392.

— of hazel "and ash-tree (Phyllactinia
suffulta), 51, 392.

— of hop (Sphserotheca castagnei), 38, 57,
115.

— of lettuce, 244, 266, 398.

— of lima bean, 242.

— of onions, 244, 398. .

— of was and lieans (Erysiphe communis),
48, 113, 115, 150, 184, 191, 248, 392.

— of phlox and verbenas, 329.

— of poppv, 244, 369.
_ of Le and peach, 37, 51, 103, 115, 150,

250, 329, 339, 365. 392.

— of strawberry (Sphaerotheca Humuli,
which see).

' — of trefoil, 244, 398.

— of vine. See Dematophora necatrix^
Milk as binder in copper bonillies, 284-5.

— in petroleum turps, CS., etc., emulsions,
300, 304, 348, 349.

Millet, disease of :— ^ .. ota ooq

Disinfection of seed-miUet, 3o-b, 210, Al6,

322-3.
Smut, 35-6, 210, 223, 322, 323, 406
Mindarus abietinus (spruce cochineal), 6dI.
\ Minerale Greggio, 43.
Mites. See Acari, Tinea, etc.
Modus Vivendi between parasite and plant,

29.
Mohr's insecticides, 378, 379, 380, 381.

liver of sulphur bouillie, 148.

Molasses, 109, 149, 271, 283. .

Mole cricket. See Gryllotalpa vulgaris.
Molytes coronatus (carrot weevil), 30/, 660,

'391. ^ ._.

Monilia fimicola (plaster disease), 6bb.
— frutigena (brown rot of stone fruit trees),

162^259,396.
Mouostegia rosse (rose saw-fly), 342, 3/8,

380, 395. _ ., . , •

Morille (old German """•/!.''«. jot^^ ^J?®
and fruit trees). 51, .08, 64, 99, 103,
124, 157, 185, 224, 391.
Mortaduse. See Dematophora necatrix.
Mitrt aux raf^ (rough on rats), 96.
Morthiera Mespili, 225. See Entomo-

sporium maciilatum. 1— q on

Mosses, destruction of, 106, 122, 1//-S, ill-
[Mottled umber moth or Lmie looper
(Hibernia defoliaria), 138, 352.
Mould, black, of cereals. See Helmintho-
I sporium Gramineum.

422 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Mouse, 77. See Mus nius ulus.
Muhlberg's iusecticides, 332.
Mulberry, diseases of: —
Bacterian disease of, 182, 396.
Bomliyx mori (silk-worm), 191, 210. 291,

312.
Bostrich (Tomicus ficus), 145, 387.
Cochineal (liermes, Diaspis pentagona), 76,

389-90.
Dematophora (rot), 51, 58, 64. 99.
Mildew of leaves, 103, 124, 157, 185, 224,
254, 391.
Mummification of quinces (Sclerotini

Cydonise), 259.
Mus agrarius (mouse), 92.

— ampliibius (rat), 81.
— • decumanus (rat), 92.

— musculus (mouse), 92.

— ratus, 81, 92.

— sylvestris (mouse), 77.

Mushroom, mole disease of (Mycogone per
niciosa), 81, 137, 143. 151, 225, 250,
366, 395.

Mustard, ploughing in crop of, to disinfect
soil, 134.

— wild, action of weed-killers on, 108,

118, 161, 176.
Mutualistic symbiosis, 3.
Mycogone peruieiosa (mole disease of mush-
room), 81, 137, 143, 151, 225, 250, 366,
395.
MytilaspLs flavescens (cochineal of orange),
77, 389-90.

— fulva, 343.

— pomorum, 136, 182, 187, 306, 342-3,

389-90.

N

Nauisme, 23.

Naphthalene, 103, 148, 150, 216, 327. 335,
337, 338-9, 380.

— preparation, properties, use, 343-7.

— solutions, alcoholic and benzenic as in-

secticides, etc , 344.
Naphthalinated oil, 327.
Naphthol, preparation, properties, uses, 369.
Naplitholate of copper, 369.

— of iron, 369.

— of lime, 369.

— of soda, 369.

Necrosis of wood (Nectria ciunabarina),

(Tubercularia vulgaris), 151.
Nectria ciniiabarina (Tubercularia vuh.'aris),
151, 369. 396-7.

— ditissima (canker of apple, pear, and

peach trees), 151, 185, 250, 324, .339,

366, 397.
Negril (C'olaspi<lema). 145, 345. 390.
Nematode of the beet (Heterodora Schactii),

42, 65, 99, 119, 144, 187, 395.

— of the violet, 192.

Nematodes (eel-worms), 8, 99, 119, 187, 298,
307, 397.

Nematus of gooseberry (Nematus Ribis and
N. Ventricosus). 121, 134, 146, 163,
260, 275, 279, 302, 368. 374, 377, 308.
397.

— pallidiventris, 275.
Nepticula, 70.

Nessler's insecticides, 314, 324, 330, 332,

370, 381.
Nickel, carbonate, 194.

— sulphate of, 193, 207.
Nicotine, 94. See Tobacco.
" Nitragine," 4.

Nitrates, preparation, properties, and use
as insecticides, fungicides, and weed-
killers of —
Nitrate of copper, 200, 203.

— of lead, 195.

— of mercury, 293.

— of potas]i,'l20-l.

— of silver, 197-S.

— of soda, 107, 211, 220.
■ — of zinc, 165.

Nitric ferments, 59, 110.

— acid glove, 91.
Nitrobenzene, 130, 314, -353-4, 362.
Nitrogenous bacteria, u.seful, 4.

Noctua (Noctuidse), 70, 146, 297-8, 303, 307,
384, 397.

— exclamationis, 70, 96, 384.
— ■ gamma, 157, 357, 397.

— gramen, 303, 366, 368.

— segetum (dart moth), 70, 96, 120, 275-6,

303, 336, 353, 382-3, 384.
— ■ valligera (Agrotis valligera), (Trachea

piniperda), 25, 397.
No.Tious herbs. See Weeds.
Nutrition, extra racinary, 181.

— of plants, 18.

Nutritive fluids, addition of toxic bodies,
effect of, 193, 204-7, 313.

Oak, action of HCl gas on, 89.

— copper in wood of, 206.
in leaves of, 206.

— diseases of: —

Agrilus of the pear. 164. 383.
Bombyx mouaca, 367, 368, 387.
— proeessionea, 340, 387.
Capricorn, large and small, 69, 388.
Cossus, 64, 70, 297, 336, 357, 363, 379, 390.
Dematophora necatrix, 51, 58, 64, 99. 103,

124, 157, 185, 224, 391.
Polyporus, 151, 184, 339, 368, 400.
Stag beetle, 69.
Wood leopard moth, 70.
Oats, action of SO.j gas on, 79.

— diseases of: —

Bunt, 31-2, 33, 34-5, 85-6, 103, 119, 183,

190, 197, 217-22, 245, 312, 316-23, 358,

388, 406.
Disinfection of seed-oats, 35, 85-6, 113-4,

221-2, 290, 320-1.
Grasshopi)er, 99, 120, 304, 389.
Leaf spots, 254, 404.
Kust, 36, 40, 85-6, 100, 101-2, 114, 137.

165, 166, 170, 189, 190, 193, 197, 200,

209, 210, 223, 246, 268, 324.
Smut, 31-2, 33, 35, 85-6, 113, 114-5, 119,

121, 183, 217-23, 245, 290, 292, 317-23,

358, 406.
" Occidiue," 216.
Ocueria dis))ar (gijjsy motli), 196, 297, 303,

340, 348, 363, 3/'3, 387.

INDEX.

423

Oidium of the strawberry, 50.

— of vine, 37, 44, 48, 'l02, 115, 150, 156,

162, 191, 199, 201, 24S-50, 309, 356, 358,
382 397
Oil, colza, 325, 326, 327, 351-2.

— rtsh. 300, 326. 341, 350.

— hemp-seed, 328.

— herring, 328.

— liuseed, 133, 288. 325, 326, 351.

— olive, 325, 326, 327.

— poppy-seed, 325, 326, 352.

— sesame, 326.

— whale, 299, 325, 326, 327, 328, 329, 331.
Oils and fats, 9, 325.

Ointment, Balbiani's, 338, 347.

— mercurial, 393.
Olive-tree, diseases of : —

Cochineal, 136, 351, 389.
Gum disease, 80, 114, 394.
Hylesine, 145.
Leaf spot, 258.

Smut (fumagine), 51, 77, 288, 393.
Onion, diseases of :■ — •

Disinfection, 58, 223, 279, 323.
Fly of the Inilb of, 308, 346, 385.
Mildew, 244, 398.
Smut, 223, 323, 405.
Thrips, 357, 375, 405.

— growing and CS2, 58.

Onions, formaline versus quicklime on, 323^
Oospora scabies (potato scab), 47, 84, 86-7,

110, 114, 143, 182, 2.37, 291, 301, 319-

20, 3.56, 401.
Opatrum sabulosuni, 345, 397.
Ophiobolus graminis, 143, 185, -397.
Orange-tree, diseases of : —

Cochineal, 77, 136, 152. 292, 306, 343,

389-90.
Fumagine (smut of fruit trees), 30, 51, 77,

150, 191,' 260, 393.
Orchid, disease of, 255, 370.
Organic insecticides, 260.
Organoleptic properties of wine and binders

for bouillies, 285.
Orobauche (broom-rape), brandling of hemp
and tobacco (0. Minor), 211, 397.

— of clover (O. Minor), 211, -397.
Orthocraspeda trima, 196.
Orthoptera, 338.

Oryctes nasicornis (rhinoceros), 67, 330, 39/.
Otiorhynchus, 351.

— hirticornis, 345.

— Ligustici (Liveche's weevil), 68, 391-2.

— of the vine, vine weevil (0. Sulcatus), 68,

307, 335, 391.

— picipes, 68.

— populeti, injurious to vine, 340.

— raucus, 68.

Oxycarenus hyalinipennis, Costa, 304.
Oxychloride of copper, 201.

P

Paint as an asphyxiant insecticide, 327.

Pal injector, 11, 30.

Paper' (tly), 376.

Pai)ilionacetB, action of SO., on, 79.

Papilionaceous crops after lucerne, 57.

Paraffin, 294, 337.

Para.sites, absolute, 3.

— animal, 2-3.

Parasites, facultative, 3.

— polyphagic, 19.

— vegetable, 2-3.

— wound, 3.
Parasitic lungi, 8.

'' Parasiticine," 314.
Parenchymatosis, 1.
Paris green. See Emerald Green.
Par.sley, diseases of : —

Cercospora apii, 52, 258, 388.

Leaf spot, 71, 254, 404.

Septoria petroseliui, 52, 71, 404.
Peach-tree, 280.

— diseases of : — ■

Aphis per.sicje, 76, 152. 377, 385.

Cochineal, 136, 306, 389-90.

Exoaseus deformans (leaf curl), 151, 184.

246, 282, .398.
Grapolitha, 146, 341.
Mildew, 38, 51, 103, 115, 150, 250, 329.

339, 365, 392.
Monilia, 162, 259, 396.
Rust of kernel fruit tree, 246, 266, 403.

— trees, .spraying with emerald green, 270.

■ sensitiveness to copper arsenites, 271.

Pears, stony, 22.

Pear-tree, diseases of :■ —
Agrilus sinuatus, 164, 383.
Anthonome, 80, 146, 186, 273, 343, 385.
Aphis. See Aphides.
Aspidiotus ostreaformis, 306.
Bitter rot, 116, 142, 255, 267, 394.
Borabyx chrysorrhea, 21-2, 80, 260, 386.
Browning of leaves (bruiiissure), (Phyllo-

coptes Schlechtendali), 53, 375, 388.
Cochineal, 40, 306, 390.
Entomosporium maculatum, 164, 167, 169,

170, 187, 199, 201, 257, 267-8, 277, 279,

281.
Erinosis, 53, 375, 388.
Eriocampa, 53, 116, 146, 260, 275, 331,

352, 374, 377, 380, 392.
Fusicladium, 116, 151, 159, 182, 209, 225,

257, 267, 273, 393.
Gvmnosporangium Sabinae ( pear leaf cluster

'cups), 246, .394.
Leaf spots, black, 114, 225, 254-7.
Lygus, 304, 396.
Nectria (canker), 151, 185, 250, 324, 339,

366, 397.
Polyporus sulphureus, 151, 400.
Polvstigma (leaf blister), 2.50.
Psvlla, 112, 304, 352, 358, 400.
Pvralis of the pear, 38, 138, 146, 276, 340,

'352, 367, 389.
Saw-flv (Tenthredo). See Eriocampa.
Sesia, "64, 70, 336, 379, 404.
Tiger beetle, 30, 117, 146, 304, 307, 336,

357, 375, 404.
Pear-tree oyster scale, 306.
Peas, diseases of: — ■
Altise, 302, 384.
Bruchus, 37, 68. 309, 388.
MUdew, 4^, 113, 115, 150. 184, 191, 392.
Mildiou (Peronospora Viciffi), 244, 399.
Noctna gamma, 157, 357, 384.
Red .spider, 40, 53, 1.32, 152, 333, 405.
Thrips, 308, 333, 367, 405.
Pellegrini's bouillie, 169.
Pemphigus, 70.

424 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Penicilliuni glaucum, 3, 208, 355.
Pentatoma baccarum, bug of fruit trees, 374.

— oleracea (cabbage bug), 40, 304, 342, 357,

367, 398.
Penthima atra (cicadella of vine), 304.
Pentodon punctatus, 67, 398.
Perchloride of iron, preparation, properties,

use, 170.

— of mercury, preparation, properties, and

use, 288.
Peridermium oblongisporium (vesicular rust
of pine needles), 151, 40-3.

— plni (vesicular rust of pine bark, pine

cluster cups), 151, 246, 403.
Periplaneta orientalis (cockroach), 92.
Peritelus of vine, 68, 139, 351, .398.
Permanganate of potash, 190.

— bouiilies, 191-2.

Peronospora arborescens (mildew of poppy),
244, 369, 398.

— cubensis, 244.

— ganglioformis, mildew of lettuce, 244, 266,

.398.

— Schachtii (mildew of beet), 243-4, 398.

— Schleideni (mildew of onion), 243-4, 398.

— trifoliorum (mildew of trefoil), 243-4, 398.

— Vicire (mildew of peas and vetches), 243-4,

398.

— Viticola (mildew of vine), 44 et seq., 86, 89,

106, 109, no, 121, 1.39, 1.50, 162, 163,
166, 167, 175, 183, 190, 192. 193, 194,
197, 198, 210, 212-3, 242, 266, 281, 282,
290, 291, 293, 324, 365, 369, 382, 398.

Peronospore«, 47, 48, 113, 162, 209, 237, 398.

Petroleum, 132, 288, 293-306, 328, 338, 342,
373.

• — American, 294.

— Caucasian, 294.

— origin of, 294.

— products, 294.

— properties, 295.

— use as : —

Emulsions, 298.

Emulsion with metallic salts and in-
secticides, 300-1.

Fish oil emulsion, 300.

Lime ami petroleum emulsion, 298-9.

Salt water emulsion, 299.

Sand emulsion, 298.

Soap emulsion, 299.

Water emulsion, 298.
Phsedon armoraciw (chrysomelide of radish),

302.
Phalena of the ap])le-tree (Eunomos sub-

sigiiaria, Cheiiuatoba brumata, winter

moth), 138, 146, 195, 276, 340, 352, 367,

389.

— of the gooseberry (mag])ie moth, Abraxas

grossulariata), 121, 363, 374, 377, 383.

— of pine (Fidonia ])inaria), 25, 393.
Phenol (see Acid, Carbolic), 14. 162, 170,

305, 338, 343, 354-8, 372, 376.

Phenols, 8.

Phlacetonodes sticticalis, 138.

Phloeotribus liminaris, 3-30.

Phloioplasty, detiiiitioii of, 6.

Phlox Dnumiioiiilii mildew, 329.

Phoma bct.-e, I'lioma tabitira (disease of beet-
leaf stalks), •Z\, 36, 84, 143, 225, 355,
399.

Phorodon humuli (hop aphis), 139, 351, 385.
Phosphate of copper, 268.
Phosphide of calcium, 93, 157, 309.

— of hydrogen (phosphorette<l liydrogen),

93, 157.
Phosphorus, 92-3.
Phragmidium subcorticum (rose rust), 151,

209, 284.
Phyllactinia suffulta (hazel-tree blight), 51,

392.
Phyllerium erinoses, 152, 392.
Phyllobius oblongus, 331.
Phyllocoptus Sehlechtendali, Nal. (lorowning
' of leaves, brunissure of apple and pear
trees), 53, 375, 388.
Phyllodia, 23.
Phvllosticta pirina (spots of leaf of pear),

116, 255.
— ■ sphffiropsidia (chestnut leaf .spots), 164,

167, 170, 188, 2.55.
Phyllotreta nemorum (altise of crucifers),
302, 384.

— nigripes (altise of crucifers), 302, 384.
— ■ sinuata (altise of crucifers), 302, 384.

— undulata (altise of crucifers), 302, 384.
Phylloxera of vine (Phylloxera vastatrix),

5, 14, 17, 36-7, 42," 53, 70, 71-6, 81,
93, 96, 99, 100, 101, 107. 122, 124, 125,
126, 127, 128, 129, 130, 131. 134-7, 139,
151-2, 153, 157, 158, 166, 293, 297, 310,
313, 316, 326, .334, 347, 351, 352, 375,
377, 381, 399.

Physical causes of disease, 1.

Phytocoris nulitaris (orchid bug), 377.

Phytonome variable (beet weevil), 307-8,
335-6, 391.

Phytonomus punctatus (weevil), 24, 391.

Phytophora, 113.

— infestans, De Bary (potato disease), 86,

89, 90, 110, 119, 121, 14-3, 166, 169,
175, 182, 209, 210, 211, 212, 238, 265,
273, 281, 284, 290, 292, .320, 324, 366.

Phytophthora Phaseoli (haricot disease,
Lima bean mildew), 114. 242, 281.

Phytoptides, erinoses (gall mites), 53, 117,
149, 260, 307, 377, 381, 392.

— Piri (gall mite of pear-tree), 53, 117, 260,

377, 381, 392.

— Ribi, 117, 149, 377, 381, .392.

— Vitis (erinosis of vine), 53, 117, 149, 392.
Pickling of .seed-corn. See Disinfection.

" Picrofoetidine," 327.

Pierides, 38, 107, 146, 276, 303, 330, 340,
400.

— of cabbage, white cabbage butterfly, 38,

107, 146, 276, 303, 330, 340, 400.
Pieris Brassiere (white cabbage butterfly), 38,
340, 400.

— Rapffi (white Initterfly of turnip), 38, 276,

330.
Pilosis, 23.
Pine, diseases of, 259.

Bombyx, 25, 146, 340-1, 387.

— monaca, 367, 368, 387.

Cockchafer. 335.

Fidonia (I'halena), 25, 393.

Hylesinus, 25, 145, 39.5.

Hylobius nbietis, 24, 395.

Kermes, 306.

Lophodermium (leaf cast), 258-9, .396.

INDEX.

425

Pine, diseases of— ccJf^ _^_, „„,

Loph\TUS, 25, 146, 302, 368, 3/4, 39d.
Lyda" red-lieaded, 25, 396.
Noctua, 25, 397.
Red rot of, 368. _

Rust, vesicular, of bark, pine cluster cups,
151, 246, 403.

of needles, 151, 403.

Weevil (Pissodes notatus), 400.

— plantations, benzene versus CS.> injections

in, 335. ,

— seed beds, preserving from birds, 190.
Pinus sylvestris, 69.
Pitch, white (oleo-re.sin), 326.
" Pitteleiue," 338, 340, 343.
Plane-tree leaf disease, 22o, 394.
Plants, adventitious. See Weeds.

— disinfection of, 37-40, 131-6.
— • parasitic, 211. ,/^ i ii ^

— rooted, disinfection of, 3<-40, 131-0.
Plasma (vegetable), 3.
Plasmodiopliora Brassica (Anbury, huger

and toe), 122, 144, 400.

— Califomiea (browning of the leaves ot the

vine), 237, 388.
Plasmopara cubensis, mildew ot cucurbitaceae,
cucumber family, 244. .o iki -

Piaster (gypsum, sulphate of lime), 42, 104-^
327. ^_

— disease of edible mushroom, 3bb.
Plastering, 154-7. ^ c v. t-\
Pleospora putrefaciens (rot ot heart ot beet),

24, 36, 185, 225, 399.
Plum-tree, disease of :—

Altise (Haltica chalybea), 274, 384.

Eriocampa (tiy), 380, .392.

Exoascus (pockets), 248, 393.

Grapholitha Woeberiana, 14b, 341, 394

Hyponomeuta (ermine moth), 138, 304
395.

Leaf fall of (Cylindrosporium padi), 254.

— blister, 250, 254, 267. 271, 400.

Magpie moth, 121, 363, 374, 377.

Pyralis, 129, 134, 275, 401.

Rust of stone fruit trees, 246, 26b, 403.

Scolytus rugose, 145, 164, 404.
Plum-trees, action of ammonia, 98. _
Plusia gamma (Noctua gamma), 157, 35/,

•397.
Plutella cruciferarum (cabbage tinea), 196,

Pockets,' plum (Exoascus pruni), 248,

393.
PodosphierK oxycantlia (mildew ot hawthorn,

apple, and cherry), 250, 266, 392.
Polleu sensitive to copper salts, 207. _
Polygonum aviculare, 124, 132, 136-7.
Polyhalite, 117.
Polypore* (polyporus), 151, 184, 3-39, -ibS,

' 400.
Polyporus destructor, 368.

— fulvus, 184.

— iguiarius, 151, 339, 400.

— pint (red spot), 368.

— sulphureus, 151, 400.

— vaporarius, 368.
Polystigma rubrum (plum leaf blister), 2o0,

400.
Polysulphide of lime, 148 <'t seq.
Polysulpbides of potash, 113, 314.

244,

" Pomoline," 327.
Poplar, diseases of: —

Dothicliiza, 186, 391.

Polyporus sulphureus, 151, 400.

Saperda (shagreen), 64, 69, 379, 403.

Sesia apiformis, 70, 336, 404.
Poppy, diseases of : —

Apiiis papaveris, 331, 385-6.

Leaf spot, 258, 369.

Mildew (Perouospora arborescens),
369.

Rust (Uroniyces diauthi), 286, 370.

Weevd (H\ pera polygoni), 69, 391.
Potash and "its' salts, manufacture and use

Potassium arseniate (stimulant), 208.

— bichromate, 188-9.

— bisulphite, meta, 50.

— carbonate, 121-3.

— caustic, 112.

— chloride, 117, 120.

— chromate, 188-9.

— cyanide, 12, 130, 13_6.

— diuitrocresvlate, 367.

— hydroxide (hydrate, caustic potash),
112, 350.

— nitrate, 120-1.

— permanganate, 190.

— sulphate, 117-20.

— sulphide, 112-7.

— sulphocarbonate, 17, 74, 123-9.

— sulphocyanide, 136.

— xanthogenate, 129-30.
Potato, disease of : —

Alternaria Solani, 253, 384.

Altise, 302, 384.

Aphis, .303, 333, -376, 381.

Bug (Halticus Uheleri), 304.

Cicadella, 304, 389.

Colorado beetle, 95, 196, 260, 2/4, 3/9,

Disease,' 86, 89, 90, 110, 119 121 143,
166 169 175, 182, 209, 210, 211, 212,
23/! 265, 273, 281, 284, 290, 292, 320,

DifnfeSn, 212, 237, 279, 301, 319-20,

.356, 361.
Epilachna, 275, 392.
Frisolee, 23.

Gangrene of stem, 47. ^^
Noctua gamma, 157, 357.
_ segetum, 24, 70, 96, 120, 275-6, 303,

336, 3 .3, 382, 384.
Pox, 291, 320.
Rot, 47-8, 401.
— of stem, 291.

Scab, 47, 87, 89, 110, 114, 143, 182,
2.37, 291, 301, 319, 356, 401.
Potter's clay, 281. . .

Powdering with plaster of pans as insecti-
cide, 156.
Powders, dusting, 12. ^^

— " Antimildioidium," 21b.

— "Bouillie d'Azur," 216.

— "Coignet," 216.

— " Crochepeyre," 216.

— "Cupreina," 216.

— Cuprohydrocarbonate, gelatmous, .ilb.

— Eclair, 216.

— Fonta, 162.

426 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Powders, Fostitebriihe, 216.
• — Skaviisky, 216.
• — sulfatiue, 216.

— tobacco. See Snutf.

— various others, 215-17.

Preventive summer and winter treatment,

16-17.
Processionary bombyx, 340, 387.
Props, 339-40.
Protection of pine seed, 194.

— of seed against granivorons birds, 194,

343, 377, 381.

— of seed beds, 194, 343, 377, 381.

— of sown fields against birds, 194, 343,

377, 381.
Proteus vulgaris, 84.
Protocliloride of mercury. See Calomel.
Protococcus, 165, 208.
Pruning, effect of, 1.
Prussian blue, preparation, properties, use,

188.
Prussiate, vellow, of potasli, 187-8.
Psila Ros!ie"( carrot fly), 306, 308, 401.
Psylla (leaf fleas), il2, 304, 305, 352, 377,

381, 401.

— of the apple-tree (Psylla mali), 112, 305,

3.^2, 358, 401.

— of tlie pear (Psylla pirisuga, Psylla piri,

Psvlla piricola), 112, 304, 352, 358,

401.
Psylloides affiuis (altise of tlie potato), 274,

302, 384.
Puecinia (rusts), 36, 48, 113, 184, 190, 209,

223, 245, 281, 292.

— compositarum (rust of eompositae), 246.

— coronata (rust of oats), 36, 40, 85, 100-2,

114, 121, 165, 170, 188, 189, 190, 193,
197, 200, 223, 268, 269, 324, 403.
■ — graminis (common rust), 36, 40, 85, 110,
114, 121, 166, 175, 189-90, 193, 197,
200, 210, 223, 266, 269, 324, 403.

— prnni (rust of kernel fruit trees). 246,

266, 403.

— RiV)is (rust of goosebeiTy), 246, 403.

— Rubigo vera (rust of wheat). 40, 85,

143, 170, 200, 223, 268, 269, 403.

— Tanaceti, 246, 403.
Puceron. See A})liis and Aphides.
Pucerotte (altise of vine), which see.
"Puknos," 102, 198.

Pulviuaria Vitis (red cochineal of vine), 77,
82, 88, 136, 147, 306, 337, 342-3, 375,
390.
Purin, 153, 164.
Putridity of seedlings, 23.
"Pyoctanine" (nietliyl violet), 370.
Pyralis of tlie ajjjjle (Carpocapsi pomo-
nella, worinv a))])les, ajjple worm,
codlin moth)," .53, 129, 134, 151, 196,
275, 346, 318, 380, 401.

— of the pear, 275.

— of the ])him (Oarjiocaiisa fimcbrana), 129,

134, 275, 40].

— of the vine (Tortri.\ vituna), 8, 39, 40, 82,

88, 90, 91, 260, 288, 292, 342, 392,

401.
Pyrethra, 129, 307, 378-81.
Pyridine bases, .361.

Pythium de Barvanuiii (darning oil), 36,
84.

Q

Quassi amara, extraction and use, 307, 313,

328, 375-7.
Quassine, 376.

Quicldime versus foimaline on onions, 323.
Quince-tree, 237, 250, 257, 259.

R

Rabbits, 343.
Radisli, diseases of :—

Anbury (Hnger and toe). 122, 144, 400.
Entomoscelis, 275, 380, 392.
Fly, 112, 306, 308, 400.
Saw-flv (Tentliredo), (Athalia spinarum),
380, 386.
Rape cake, destruction of wire- worm bj', 8.
Raspberry, diseases of: —
Gloeosporiam venetum. 255, 394.
Leaf spots, 254, 268, 394.
Rats and mice (Mus amphibius, Mus ratus,
Mus decumauus, ordinarv rat), 25, 77,
81, 92, 96-7, 112, 139, 293, 343, 368,
377, 382.
Red lead, preparation, properties, and use,
196.

— spider. See Tetranychus.
" Reflorit," 358.

Reseda (mignonette), leaf spots, 258, 389.
Resin (1 rosin) of pine, 349-52.

— {I rosin) of spruce, 349-52.

— (rosin) soaps, 288, 349-.52.
Respiration of immersed viue roots, 29.
Rliinoceros (Oryctes nasicornis), 67, 330, 397.
Rliizobium leguminosarum, 4.
Rliizobius, 70.

Rhizoctinia of asparagus, 320, 401.
— • of the beet (Rliizoctiuia violacere), 36, 143,
156, 185, 356, 401.

— of vine, 64.

— Solani (potato pox), 291, 320.
Rhizotrogus marginipes (St. Jolin cock-

cliafer), 67, 390.

— solstitiales (St. John cockcliafer), 67, 390.
Rliopobota Vacciniana, 196.

Rhyuchites Fragariaj, 373.

Rice weevil, 68.

Ring trap of bird-lime, 16.

Ro.lents, 25, 77, 96, 1-39, 157, 293, 377, 382.

Roesleria hypogea, 58.

Roestelia caucelhita (iiear leaf cluster cups),

246.
Roucet, bacillary gununosis of vine, 24.
Root liairs, reconsdtution of, 28.

— of liellebore. Si'c Hellebore Root.
Roots, disinfection of. 36-7, 63. 70, 130, 295,

297, 384-5. j
Rose laurel, 382. /

— ■ — cocliineal of, 332.

— - tree, 280r

— diseases of : — ■
Aphis, 76, 331, 385.

Botrytis cinerea, 143, 156, 157, 162, 163,

259, 284, 320, 387.
Cecidoniva, 374, 381, 338.
Fly, 374; 381, 388.
Hvlotome, 342, 378, 380, 395.
M'il.lew, 37, 51, 103, 115, 150, 250, 329,

339, 365, 392.

INDEX.

427

Rose, diseases of — cont.

Rust, 150, 284, 370.

Saw-flv, 34-2, 378, 380, 395.

Tetranydius, 40, 53, 132, 152, 333, 347,
405.'
Rosin, 10. See Resin.
Rot, bitter, of fruit. 116, 142, 255. 267, 394.

— black, of :ipples, 250.

— — of cri-apes, 90, 103, 143, 191, 250-3,

266, 281, 284. 292, 309, 366, 386.

of pears, 250.

■ — — of quinces, 250.

— brown, of stone fruit trees, 162, 259, 396.
— • Guigiiardia Bidwelli. wliicli see.

— grev, of vine, 143, 156, 157. 162, 163, 259,

284, 320, 387.

— of apple-trees (Hvdiium Scliiedermayri),

151 395.

— of beets, heart of, 24, 36, 185, 225. 399.

— of cuttings, slips (propagation), 339.

— of grapes, 51, 86-7, 143, 169, 185, 225,

385.
• — of potato (gangrene), 47-8, 401.
• stem, 291.

— of roots, 156.

— of sweet p itato, 47-8.

— of timber (dry rot), 88, 362, 396.

— red, of pine, 368.

— white, 162, 253, 402.
of oak, 151, 400.

Rotation of crops, needless after CS.j, 57.
Rouge du pin (fall of needles of pine), 151,

258, 403.
" Rubinia," 260, 307. 338, 341, 342.
Rusts (Puccinia urediuse), 36, 48, 113, 184,

188, 189, 190, 209, 223, 245, 281, 292,

370, 402, 403.

— coiiimon, Puccinia graminis (rust of

cereals), 36, 40. 85, 110, 114, 121, 165,
170, 188, 189, 190, 193, 197, 200, 222
266. 269, 324. 403.

— crown of oats (Puc -iuia coronata), 36, 40,

85, 101-2, 114, 121, 165, 170. 188, 189,
190, 193, 197, 200, 222, 260, 269, 324,
403.

— grilled, of pear-tree (pear leaf cluster cups),

246, 394.

— (spotted) of wheat (Puccinia Rubigo vera),

40, 85; 143, 170, 200, 210, 223, 268,
269, 403.

— of asparagus, 369.

— of beet ( Uromyces Betre), 246, 402.

— of compositte (i'uccinia compositarum),

246, 403.

— of gooseberry (^cidiuni grossulariie, Puc-

cinia Ribis), 246, 403.

— of Juniper (pear leaf clu.ster cups), 246,

394.

— of kernel fruit trees (Puccinia pruni), 246,

266, 403.

— of mulberry leaves 'Cylindrosporium Mori,

Sphoerella Morifolia). 254, 403.

— of poppy (Uromyces Dianthi), 286, 370.

— of rose-tree (Actinoueina Ro-sse, Asteroma

racliosum, Phragmidiuni subcorticum),
150, 284, 370.

— of spruce-tree needles (Chrysomyxa

abietis), 151, 403.

— (vesicular) of pine needles (Peridermium

oblongisporium), 151, 403.

Rusts (vesicular) of pine bark (Peridermium
pine wall, pine cluster cups), 151, 246,
403.

— (white) of composita; (Cystopus cubicus,

salsify disease), 48, 403.

— — of crucifers (Cystopus candidus), 48,

403.
Rusting of hop leaves (Tetranychus althese)„

375.
Rye, 110.

— diseases of : —

Ergot (Claviceps purpurea), 86, 113, 121,
166, 175, 185, 209, 210, 224, 293.

Smut of stems of ( Urooystes occulta), 35,
406.

Spotted rust (Puccinia Rubigo vera, which.
see).

Tlirips, 308, 333, 367, 405.

Saccharate of copper, 283-4, 287.

— of lime, 287.
Saccharomyces ellipsoides, 208.
Sainfoin, disease of : —

Liveche's weevil, 68.
Salsify, diseases of :—

Disea.se, 48, 403.

Dusky click beetle, 68, 95, 383.
Salt as manure, 105.

— marine. See Sodium Chloride.
Saltpetre potassium nitrate, 120-1.

— (Chili) sodium nitrate, 107-8.
Sand, inhospitable to insects, 25.

San Jose louse (Aspidiotus perniciosus), 107,
122, 136, 147, 152, 296, 306, 327, 332,
351, 390.

Saperda, 64.

— Carcharias (shagreen sapenla), 69, 335.

— Populnea (saperda of poplar), 69, 379, 404.
" Sapocarbol," 359-60.

Saprophytic fungi, 207.

Sawdust, 336.

Saw-fly. See Tenthredo.

Scalding, killing para-sites in winter by, 12.

Schizoneura srrossulariie. 76, 377, 380.

— lanigera, 37, 64, 76, '88, 99, 107, 110, 111,

122, 132, 147, 163, 187, 191, 297, 305,
313, 324, 326, 331, 342, 346, 349, 352,
354, 357, 360, 361, 363, 365. 367, 374,
377, 381, 382, 406.
Sclerotinia Cidonine, Schell (mummification of
quinces), 259.

— Fuckeliana. See Botrytis cinerea.

— Libertiaua, 19.

Scolvtides (Scolvtidffi, scolytes), 7, 24, 134,

l45, 275, 296, 302, 363, 404.
Scolytus of elm (Eccoptogaster .scolvtus), 145,
404.

— of fruit trees (Scolvtus Rugulosus), 164,

404.
■ — of plum-trees (Scolvtus Pruni, Scolytes
Pruni), 145, 164, 404.

— rugose (Eccoptogaster Rugulosus), 145,

164, 340, 404.
Seeds, disinfection of. See Disinfection of

Seeds.
Selandria adumbrata (slimy caterpillar of

pear-tree saw-flv), 53, 116, 146, 260, 275,

331, 352, 374, 377, 380, 392.

428 INSECTICIDES, FUNGICIDES, AND WEED KILLEES.

Senecio vulgaris, 289.

Septoria cerasina (Coryueum Beverincki, leaf
spot of keruel fruit trees), 254, 324, 404.

— graminum, 254, 404.

— Lynopersici (Tomato disease), 254, 404.

— ni'gerrima (pear-tree leaf spot), 254, 404.

— Petroselini (parsley leaf spot), 51, 254, 404.

— Piricola (pear-tree leaf spot), 116, 254,

404.

— Ribis (gooseberry leaf spot), 254, 268, 404.

— Rubi (bramble and raspberry leaf spot),

254, 268, 404.

— Socia (chrysanthemum leaf spot), 254,

404.

— Tritici, 254, 404.
Sesia, 14, 70, 379, 404.

— apiformis, 70, 3-36. 404.

— of the pear (Sesia myopiformis), 146, 404.
Silicates, preparation, properties, and use of,

as fungicides, insecticides, and weed-
killers : —
Silicate of alumina, 164.
— ■ of copper, 277.

— of magixesia, 162.

— of soda, 10, 357.

— of zinc, 167.
Siloing, use of salt in, 107.
Silph black (Silpha atrata), 274, 404.

— opaque (Silpha opaca), (beet carrion beetle),

274, 298, 324, 330, 345, 404.
Sinapis arvensis (wild mustard), 289.
Single versus multiple spraying, 13.
Sitones lineatus (striped pea weevil), 362, 373,

391.
Sitotraga cereallela (alucite of cereals), 70, 82.
Smuts. See Ustilagineai.
Snails and slugs, 120, 147, 157, 225, 226, 339,

381.
Soil, disinfection of, 57-9, 179, 298 et seg.,

316. 334-5.
— ■ exhaustion of, 19, 57 et secj., 71 et seq.
Soap as binder in copper bouillies, 284-8.

— black, 116, 129, 133, 143, 293, 299, 328,

.359.

— emulsions, 76, 346.

— fish oil, 299, 328.

— hard, 327.

— Marseilles, 143, 327.

— soft, 116. 129, 130, 143, 149. 152, 29.3,

300, 328, 329, 330-3, 335, 342, 347, 351,
357.

— whale oil, 299, .328, 331, 332, 333.
Soaps, .52, 284, 327-30, 356.
Sodium, salts of, preparation, properties, and

use of :—
Sodium arsenite, 108-9.

— borate (bora.x), 109. 110.

— carl)Ouate, 110-11.

— chloride, 104-9.

— hyi)osul])liitc, 102-3.

— nitrate, 107, 108,220,

— silicate, 10, 357.

— sul])hate, 103-4.
Solanem, 242.
Solenojjsis geminatus, 275.
"Solutol," .3.59.
"Solveol," 3.'.9.
Sonchus olcraceus, 136, 289.
Soot, 52, 164.
Sorauer'.s bouillic, 160.

Sorrel, action of weed-killers on, 108, 118, 161.
Sparrows, 195, ."43, 377, 381.
Spermophilus citillus, 77.
Sphaceloma ampelophaga. See Anthracnosis

of Vine.
Sphserella Fragariae (strawberry leaf spots), 51,
87, 115, 254, 404.

— Morifoliffi (mulberry leaf rust), 254.

— Tulasuei (black of cereals), 405.
Sphseriacese, 404.

Splieeropsis malorum (apple rot), 250.
Sphserotheca castagnei, 37, 51, 115, 392.

— humuli, 57, 266, 392.
• — mors uvae, 115, 250, 392.

— paunosa, 37, 51, 103, 115, 150, 250, 329,
339, 365, .392.

Spilographa cerasi, 69, 70, 153, 381, 389.
Spores, summer and winter, 3, 5, 16, 32,

245.
Spraying machines, 13, 115, 234 et seq.
■ — single versus multiple, 13.

— time, best for, 9, 13.
— • with bouillies, 13, 234 et seq.

— with cold water, 30-1.

— with emulsions, 304.
— • with hot water, 37 et seq.
Spruce-tree. See Epicea.
Squirrel (ground), 97.
Stannous chloride, 293.
Staphylococcus pyrogenus aureus, 370.
Stearine, 351.

Steatite magnesium silicate (talc), 162.
Sthenic 'diseases, 2.
Stigeoclonium, 165, 208.
Stimulants plaut, 170, 192-3, 194, 203 et seq.,

229-32', 290, 311, 315.
Strachia oleracea (cabbage bug), 40, 304, 342,

357, 367, 398.
Strawberry, diseases of: —
Anthonome, .301.
Lachnosterna, 68, 120, 301.
Mildew, .50-1, 266.
Oidium. 50-1.

Red cockchafer, 335. 339, 395.
Rhvnchites, 373.

Sphierella, 51, 87, 115, 254, 404, 405. .
Thrips, 308, 333.
Strychnine, preparation, properties, uses,

381-2.
Styrolene, 337.

Sublimate, corrosive, 290 et seq. See Cor-
rosive Sublimate.
Submersion (artificial) of fields and meadows,
vineyards, and forests to iiill insects and
vernuu, 24-30.

— antiphyllo.xeric, 25 et seq.

— in practice, 26.

— of forests, 24-5.

— of vineyards, 25-30.
during active period of vegetation

of vine, 27-30.
— ■ winter, 27.
Sucker lice of plants, 14.
Sugar, per cent of l>eet increase in, by bouillie
bordelaise, 244.

— as a binder for bouillies, 246.
Sugar as bait, 109.
"SuUatine," 2l6.
" Sulpharinc," 87.

INDEX.

429

Sulphates, preparation, properties, aud use
of :—
Sulphate of aluiuiua and potash (alum),

163.
— ■ of amiuouia, 100.

— of baryta, 139.

— of cadmium, 167.

— of calcium, 155.

— of cobalt, 193, 194.

— of chromium, 188.

— of copper, 193, 201.

— of irou ferric, 187.

ferrous (greeu vitriol), 169, 171-

187, 231.

— of lime, 1.55.

— of magnesia, 161.

— of manganese, 192.

— of nickel, 193.

— of potash, 117 et seq.

— of soda, 103.

— of zinc (white \'itriol), 165, 193.
Sulphating, oil of vitriol pickling of seed-corn,

83-8.
Sulphides, preparation, properties, and use
of :—
Sulphide of ammonia, 42, 99.

— of calcium, 148-52.

— of carbon, 30, 41, 42, 54-75.

in aqueous solution, 74-6.

— - • in closed spaces, 63-4.

— in gelatinous capsules, 62.

■ — in soapy emulsion, 328.

■ — — — vaselinated, 61.

— of copper, 199.

— of iron, 42, 169-70^

— of potassium, 112-7.

— of sodium, similar to liver of sulphur,

whicli see.

— of zinc, 164.
Sulphite of copper, 201.

— of lime, 157.
Sulphoearbolate of zinc, 167.
Sulphocarbonate, 30, 42, 123-9, 132.

— of barium, 139.

— of ethvl, 129-30.

— of potassium, 30, 42, 123-9, 132.
Sulphocarbonating, 30, 42.
Sulphocyanide of ammonia, 100.

— of potassium, 100, 137.
Sulphosteatite, cupric, 215.

Sulphur, preparation, properties, and use of,

12, 42-53, 113, 118, 149, 152, 191, 216,

303, 309, 346. 347.
Sulphuretted hydrogen (hydric sulphide),

preparation, properties, and use of, 41-2.
Sulphuric acid. See Acid, Sulphuric.
Sulphurizatiou of the vine, 82.
Superphosphate in blue vitriol pickle for

seed-corn, 220.
Symbiosis, 3, 59.

Talc (steatite, soapstone), 162, 163, 212,

215.
Tallow, 352.

Talpa K>iro];ea (mole), 77, 381.
Tansy rust, 216, 403.
Taphrina (Erinoses), 53, 117, 149, 152, 276,

307, 375, .377, 381,392.

Tar, 331, 337.

— coal, 337.

— ring of, 16.

— vegetable, 3-37.

— weed-killer, 297-318.

— wood, 47, 337.
Tea, disease of, 53.
Tenthredo (saw-fly) : — •

Cherry-tree saw-fly (Eriocampa cerasi), 380.
Gooseberry bush saw-flv, 121, 134, 140,
260, 275, 279, 302, 368, 374, 380, 397.
Pear-tree saw-fly (Eriocampa adumbrata),
53, 116, 146, 260, 275, 331, 352, 374, 377,
380, 392.
Rose bush saw-fly (Cladius pectinicornis,
Emphytus cinctus, Hylotoma Rosas,
Monostegia Rosie), 342, 377, 378, 380,
395.
Turnip saw-fly (Athalia spinarum), 380-6.
Terpenes, 348.
Tetraneura, 305.
Tetrauychus Althese, 378.

— of tea, 53.

— telarius (red spider), 30, 43, 53, 82, 132,

152, 306, 3.33, 343, 347, 351, 367, 375,
405.

Therapeutics, vegetable, 14.

Thlaspi alpestre, 165.

Thrips, black, of hothouses (black fly of hot-
houses, Thrips hajmorrhoidalis), 375.

— of cereals (Tlirips cerealium), 308, 3-33,

367. 405.

— of onion, 357, 375.
" Thvmocresol," 359.
Tliymol, 368.

Tiger beetle of pear-tree (Tiugis Piri, Tingis

Pvri), 30, 117, 146, 304, 307, 336, 357,

375.

Tilletia caries, T. (bunt or stinking smut of

wheat), 34, 84, 104, 183, 190, 197, 219,

222, 311, 320, 406.

— levis (bunt), 34, 84, 104, 183, 190, 197,

219, 222, 311, .320.
Timber. See Dry Rot.
Tin crystals, SnClo, 293.
Tinea granella (grain mite), 71, 82, 346, 405.

— of apple-tree, 80, 116, 1.38. 259-60, 275,

304, 330, 341, 357, 374, 395.

— (mites), 70, 275, 303-4, 351, 405.

— of cabbage, 196, .303-4.

— of flour, 303-4, 405.

— of grain, 71, 82, 346, 405.

— of grapes (Grapholitha botrana), 196, 341.

— of stone fruit trees, 146, 341.
Tiueides, 70, 275, 303-4, 351, 405.

Tingis Piri or P\Ti of pear-tree, 30, 117, 146,

"304, 307, 336, 357, 375, 405.
Tipula crocata, 69.

— gnat of kitchen garden (Tipula prateusis),

69, 108, 137, 187, 405.

— (meadow gnat), (Tipula oleracea), 69, 108,

137, 336, 405.

— melanocera, 69.

— oleracea, 69, 108, 137, 336, 400.
Toads as destroyers of insects, 303.
Tobacco preparation, properties, and use as

insecticide, 129, 145, 147, 313, 314, 329,
331, 332, 347, 357, 362, 363, 371-5.

— juice, carbolated, 260.
Toluene, 337.

430 INSECTICIDES, FUNGICIDES, AND WEED KILLERS.

Tomato, diseases of : —
Anthracnosis, 255.
Disease, 52, 116, 150, 212, 242, 258, 268,

389.
Disinfection of seed of, 242, 356.
Leaf spot, 254, 404.
Tomicus dispar (Bostrichus dispar), 145, 164,
3? 7.

— Ficus (bostrieh of tig), 145, 387.

— Mori (bostricli of mulberry), 145, 387.
Tortricides, 275, 303, 351.

•Tortrix vitana (Pvralis of vine), 38, 39, 40,
82, 88, 90, 91, 260, 288, 292, 342, 392,
401.
Trachea piniperda (Noetua of pine), 25, 146,

397.
Trama, 70.

Trametes eryptarum (red rot of pine), 368.
Transpiration decreased by sulphuric acid,

83.
Trefoil, action of weed-killers on, 118.
— • diseases of : — •

Cockchafer, St. John's, 67.

Dodder, 87, 119, 122, 150, 178, 211, 391.

Epilachna, 275, 392.

Mildew (Ervsiphe), 48, 113, 115, 150, 184,

191,392.^
Orobanchus, 211, 397.
Tetrauychus. 30, 40, 53, 132, 152, 306, -333,

343, 347, 351, 367, 375, 405.
Weevil, 24, 391.
Trinitrophenol (picric acid), 358.
Tripeta Cerasi, Spilographa Cerasi (cherry fly),

69, 70, 153, 381, -389.
Trochilium apifonni (Sesia apiformis), 70, 336,

404.
Tubercularia vulgaris (necrosis of wood), 151,

369, 396-7.
Turnip, diseases of : — •

Anbury, finger and toe, 122, 144, 400.

Beetle," 307, 335, 391.

Butterfly (Pierides), 38, 107, 146, 276, 303,

330, 340, 400.
Saw-fly, 380, 386.
Turpentine oleo resin, 348-51.

— spirits of, 348-51.
Tychea phaseoU, 70, 76.

Tylenchus devastatrix (eel-worm of wheat),
88, 108, 144, 405.

— Tritici (eel-worm of wheat), 88, 108, 405.
Typhocyba Solani (grassliopper of potato),

304.

u

Uncinula Americana, How., 37, 44, 48, 102,

115. 150, 156, 162, 191, 199, 201,248-50,

309, 356, 358, 382, 397.
Ure.iina; ru.sts, 36, 48, 113, 184, 188, 190,

209, 223, 245, 281, 292, 370, 402, 403-4.
Uredospores, 224.
Urocystes cepulrr; (onion smut), 223, 323,

405.
Uromyces avicularia, .369.

— Be"t;p(l'ectrust), 246, 402.

— Dianthi (pojijjy ru.st), 286, 370.
Uro[)iis ulmi, 139.

Ustilaginc-e (smuts), 31 H xeq., 83-6, 103, 113-4,
119, 175, 183-4, 217-24, 245-6, 290-3,
ai7-23, 358, 406.

Ustilago Avenae (smut of oats), 31-2, .33-5,
85-6, 113, 114, 115, 119, 121, 183,217-23,
245, 290, 292, 317-23, 358, 406.

— Ijromivora (.>mut of bromegrass), 36.

— carbo (smuts). See Ustilaginese above.

— Cranieri (smut of millet), 35-6, 210, 223,

322, 323, 406.

— Hordei (smut of barley), 31-7, 85, 111, 221,

290, 406.

— Jensenii (smut of barley), 31-7, 85, 111,

221, 290, 406.

— Maydis (smut of maize), 36, 223, 245, 406.

— Panici-miliacei (smut of millet), 35-6, 210,

223, 322-3, 406.

— perennans (smut of oats). See Ustilago

Avenai.

— Tritici (smut of wheat), .33, 85, 113, 222,

290-2, 406.

Valgus hemipterus, 339.
Vaseline, 55, 308.
Vaselined carbon disulphide, 56.
Vegetable parasites, 2.
Verdigris, 279-81.
Vespa crabo (wasp), 70.
— \ulgaris (common wasp), 70.
Vesperus xatarti, 67, 345, 406.
Vetches, disease of : — •
Bruchus, 37, 68, 309, 388.
Mildew. 244, 399.
Weevil,' 37, 68, 309, 388.
Vine, diseases of : — •

Altise, 52, 146, 260, 274, 373, 379, 384.
Anthracnosis of (grape rot, Gloeosporium
ampelophagum), 51, 86-7, 143, 169, 185,
225.
Armillaria Mellea, 58, 156, 386.
Black rot of grapes, 49, 90, 103, 143, 191,
224-5, 250-3, 266, 281, 284, 292, 309, 366,
386.
" Bruuissure," 340,388.
Cochineal, white (Dactylopius Vitis), 82, 88,
343, 389-90.

— red (Coccus Vitis). 77, 82, 88, 136, 147,

306, 337. 342-3, 373, 390.
Cochylis, 38-9, 81, 90, 100, 116, 129, 187,
191, 211, 260, 281, 288, 297, 303, 307,
326, 336, 341. 346, 349, 354, 362, 367,
374, 376, 380, 390.
Cockchafer (Melolontha vulgaris), 24, 42,
58, 65, 146, 157, 297, 301, 335, 3-39,
345,351, 390.

— green, 67, 390.

Disinfection of the, 36-7, 56 et seq., 64, 90-1,

129-30, 133, 134-7, 139, 297, 299. See

Phylloxera.
Enchiora Vitis, 67, 390.
Erinosis, 53, 117, 149, 392.
Eudemis, 288, 392.

Fumagine, .30, 51, 77, 150, 191, 260, 393.
G;ape tinea, 196, 341.
Grasshopper, 304.
Gummosis bacillary (mal nero), 24, 182,

394.
Lachiiosteriia, 120. 301, 395.
Lethrus, big-heaihMl, 67, 396.
Mildiou. See Peronospora Viticola, De

Bary.

INDEX.

431

Vine, diseases of — cont.

Noctua exclamatiouis, 70, 96, 384.
Oidium, 37, 44, 48, 102, 115, 150, 156, 162,

191, 199-201, 248-50, 309, 356, 358, 382,

397.
Opatrum sabulosuni, 345, 397.
Orj-ctes uasicoruis, 167, 330, 397.
Otiorhvnchus populeti, 340.

— sukatus, 68, 307, 335, 391.
Penlxxlou puuctatiis, 67, 398.
Peritelus, 68, 139, 351, 398.
Phylloxera. See phylloxera in general body

of index.
PvraUs, 39, 40, 82, 88, 260, 288, 292, 342,

'392, 401.
Red spider, 40, 53, 132, 152, 333, 347, 405,
Rot, grev, of (BotT\-tLs einerea), 43, 156,
157", 162, 163, 259, 284, 320, 387.

— white root of (Dematophora ueeatrix),

51, 58, 64, 99, 103, 124. 157, 185,
224, 391.

— — pale livid (Coniothyriumdiplodiella),

162, 253, 402.
Violet, methyl (dye), (" Pyoctanine"), 370.

— diseases of : —
Cecidomia. 134, 380, 388.
Fly, 134, 380, 388.

Vitriol, blue (copper sulphate), 201, 226.

— green (ferrous sulphate, protosulphate of

iron), 171-87.

— oil of (sulphuric acid), 83-8.

— white (zinc sulphate), 165.

w

Wasps, 134.
Water, cold, 23-31.

— hot, 31-40.
Wax grafting, 349.

Weeds and weed-killers, use of : —
Arsenite of soda, 109.
Blue vitriol, 211.
Bouillie bordelaise, 237.
Calcium chloride, 153.

— chloro-liypochlorite (bleaching powder,

chloride of lime), 153-4.

— sulphide, 150.
Carbolic acid, 355.
Common salt, 106.
Copper nitrate, 200.

— sulphate, 211.
Ferrous sulphate, 176-8.
Green vitriol, 176-8.
Magnesium chloride, 161.
Mercuric chloride, 289.
Nitrate of soda, 108.
Potassium chloride, 118.

— cyanide, 132,

— sulphocyauide, 1-36-7.
Sulphuric acid, 85.

Weevils :—
Beet, 157. 307-8. 335-6, 391.
Cabbage, 307. 3.35, 391.
Carrot, 307, 335, 391.
Fir, 24, 391.
Liveche's, 68, 391.
Maize, 68, 404.
Pea, 36.3, 373, 391.
Poppy, 69.
Rice,"68, 391.

Vine, 68, .307, 3-35, 340, 365, 391.
Wheat, 68, 81, 345, 388.
Wheat, diseases of —

Bunt, 34, 84, 104, 183, 190, 197, 219, 222,

311, 320.
Calandra granaria, 68, 81, 345, 388.
Disintection of seed, 34-5, 85, 113-4, 166,

290, .352.
Eel-worm. See Tylenchus.
Hessian Mv, 388.

Mildew, 48, 11-3, 115, 150. 184, 191, 392.
Noctua, .303, 366, 368. 397.
Ru.st spotted, 40, 85, 143, 170, 210, 223,

269, 403,
Septoria graminum, 254, 404.
— Tritici, 254, 404.
Smut of wheat. See Ustilago.
Sphsrella Tulasnei, 36, 404.
Stalk disease (Ophiobolus graminis), 143,

186, 397.
Tylenchus Tritici (eel-worm), 88, 108, 144,

405.
Wood, dry rot of, 88, -362, 396.

— necrosis of, 151.

— tar, 47, 337.

creosote, .337, 362.

Woolly aphis. See Schizoneura Lanigera.

Xanthogenate of potassium, 129-30.

Zabrus Gibbus, 273, 406.

Zeuzera .Esculi, 78, 3-36, 406.

Zig-zag (Bombvx dispar), 196, 297, 303, 340,

.348, 363. 373, -387.
Zinc salts, preparation, properties, and uses

of :—
Zinc borate, 166-7.

— chloride, 165.

— ferrocyanide, 167.

— sulphate, 165.

— sulphide, 164.

— sulphocarbolate, 167.
i Zoospores, 212, 224, 244-5.

ABERDEEN : THE CKIVERSITY PRESS.

/ I

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HORTICULTURAL
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