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US DEPSR IMENT OF AGRICULTURE.
BUREAU OF PLANT INDUSTRY—BULLETIN NO. 121.
B. T. GALLOWAY, Chief of Bureau.
MISCELLANEOUS PAPERS.
I. THE SUPPOSED RELATIONSHIP OF WHITE SNAKEROOT TO MILKSICKNESS,
OR © TREMBLES.”
By ALBERT C. CRAWFORD, Pharmacologist, Poisonous- Plant Investigations.
IT MOUNTAIN LAUREL, A POISONOUS PLANT.
By ALBERT C. CRAWFORD, Pharmacologist, Poisonous- Plant Investigations.
III. RESULTS OF LOCO-WEED INVESTIGATIONS IN THE FIELD.
By C. DWIGHT MARSH, Expert, Poisonous-Plant Investigations.
LABORATORY WORK ON LOCO-WEED INVESTIGATIONS.
By ALBERT C. CRAWFORD, Pharmacologist, Poisonous-Plant Investigations.
IV. THE SOURCES OF ARSENIC IN CERTAIN SAMPLES OF DRIED HOPS..
By W. W. STOCK BERGER, Expert, Drug-Plant Investigations.
VY. APPLE LEAF-SPOT CAUSED BY SPHAEROPSIS MALORUM.
By W. M. SCOTT, Pathologist, and JAMES B. RORER, Assistant Pathologist,
Investigations of Diseases of Fruits.
VI. THE IMMUNITY OF THE JAPANESE CHESTNUT TO THE BARK DISEASE.
By HAVEN METCALF, Pathologist in Charge of the
Laboratory of Forest Pathology.
IssuED AprRiIL 18, 1908.
oa 3 Lae we
LY ago UANVERETUN SS
Ce
WASHINGTON:
GOVERNMENT PRINTING OFFICE.
1908,
BUREAU OF PLANT INDUSTRY.
Pathologist and Physiologist, and Chiefof Bureau, Beverly T. Galloway.
Pathologist and Physiologist, and Assistant Chief of Bureau, Albert F. Woods.
Laboratory of Plant Pathology, Erwin F. Smith, Pathologist in Charge.
Investigations of Diseases of Fruits, Merton B. Waite, Pathologist in Charge.
Laboratory of Forest Pathology, Haven Metcalf, Pathologist in Charge.
Truck Crop Diseases and Plant Disease Survey, William A. Orton, Pathologist in Charge.
Plant Life History Investigations, Walter T. Swingle, Physiologist in Charge.
Cotton Breeding Investigations, Archibald D. Shamel and Daniel N. Shoemaker, Physiologists in Charge.
Tobacco Investigations, Archibald D. Shamel, Wightman W. Garner, and Ernest H. Mathewson, in
Charge.
Corn Investigations, Charles P. Hartley, Physiologist in Charge.
Alkali and Drought Resistant Plant Breeding Investigations, Thomas H. Kearney, Physiologist in
Charge.
Soil Bacteriology and Water Purification Investigations, Karl F. Kellerman, Physiologist in Charge.
Bionomic Investigations of Tropical and Subtropical Plants, Orator F. Cook, Bionomist in Charge.
Drug and Poisonous Plant Investigations and Tea Culture Investigations, Rodney H. True, Physiologist
in Charge.
Physical Laboratory, Lyman J. Briggs, Physicist in Charge.
Crop Technology and Fiber Plant Investigations, Nathan A. Cobb, Crop Technologist in Charge.
Taxonomic and Range Investigations, Frederick V. Coville, Botanist in Charge.
Farm Management Investigations, William J. Spillman, Agriculturist in Charge.
Grain Investigations, Mark A. Carleton, Cerealist in Charge.
Arlington Experimental Farm, Lee C. Corbett, Horticulturist in Charge.
Vegetable Testing Gardens, William W. Tracy, sr.. Superintendent.
Sugar-Beet Investigations, Charles O. Townsend, Pathologist in Charge.
Western Agricultural Extension Investigations, Carl S. Scofield, Agriculturist in Charge.
Dry-Land Agriculture Investigations, E. Channing Chilcott, Agriculturist in Charge.
Pomological Collections, Gustavus B. Brackett, Pomologist in Charge.
Field Investigations in Pomology, William A. Taylor and G. Harold Powell, Pomologists in Charge.
Experimental Gardens and Grounds, Edward M. Byrnes, Superintendent.
Foreign Seed and Plant Introduction, David Fairchild, Agricultural Explorer in Charge.
Forage Crop Investigations, Charles V. Piper, Agrostologist in Charge.
Seed Laboratory, Edgar Brown, Botanist in Charge.
Grain Standardization, John D. Shanahan, Expert in Charge.
Subtropical Laboratory and Garden, Miami, Fla., Ernst A. Bessey, Pathologist in Charge. /
Plant Introduction Garden, Chico, Cal., August Mayer, Expert in Charge.
South Texas Garden, Brownsville, Tex., Edward C. Green, Pomologist in Charge.
Cotton Culture Farms and Farmers’ Cooperative Demonstration Work,Seaman A. Knapp, Special Agent
in Charge.
Seed Distribution (Directed by Chief of Bureau), Lisle Morrison, Assistant in General Charge.
/
Editor, J. E. Rockwell.
Chief Clerk, James E. Jones.
CONT ENG
Page.
The supposed relationship of white snakeroot to milksickness, or “*trembles”’. D
EIS COMED AMG ROCUMNCHIOMM eas 6a. Gk) ate ear hes is eee hnroanat aie, nkeahias ee tae 2 5
VECEMUMINVES CATT OMG Me coy Me me rs a ANT Te eS De ae peels beat 15
iectron winitesnakerootion-rabbitsies 94.522 en eee en 15
IH xabra CE Seukormuc sya lant: sles 8 He Gee ea We epee a eae 15
Extracts from fresh plants preserved in chloroform...........-.--- 16
IB KsfeTEN C lis wins, MnsreNs Lie) pe sree, Paes s | Serato ua cain) en dum e Coy aa Wh 17
Bech: Orawilite; smakeroot OMs Catset en veoh NAA eee cee ye one 17
Nitecthon white snakeroot onedoess/s\9-.5 Neon Pe a ee 18
Hifeet ol whitessnakeroot om sheeps 42-2 4.05. ee be oe a 19
itech on whutesnakerootom manos Neri, ee 19
(SROWOO ESTE as a yey tes i SACU eT HOOT Mle Sa eet ec ic a Pe Ea 19
Motmntamelaurela poisonous plantsee es . .:4 geste: 1. = ben se ee ne ee 21
Ei stonicaleimGrochiCiionem same on cross ae Sak ee oe Sea iat ae 21
Mieewormounbarm laurelvonesltee ples ett eis hh yee eu sites 26
Bec Olmountamelaunrellon tab bis ss 2s kee eee 29
General symptoms of poisoning. ....-..-- Pe eRe eet a Mee een UR seg Tc ee 30
INEbEVIC PRUMCIPlCTS eine eee nen neki ae as pa e Ie Gt Aha peep te has Sia 30
Remedial agents....-..-.- Sars gee gen eats Cots acca Mele Nr ga AS Scheel sim ML cea 34
Medicimaleactiom's: soe see oo PS INE | AR IIONY Tee! te Were ty ok Slee ee Rte 34
Rvesultsiot locosweed investigationsam the field 2022. es) ein ee oi
UR ONG SOLES See ea EL Se ope Se eat ee EN ce GR 37
Laboratory work on loco-weed investigations....................... goed ba eRe 39
SUMIMAT yO lalboratonyayjObkey et a nee a See oe so ea eae 39
The sources of arsenic in certain samples of dried hops....-................-- 41
BlimGrociinctiomepesi yey aii ee hy fn coders Pere ak ona SAGE Tae mere 2A 41
Onicimotsanmples of hops examimed ss. enacts ee. 1 42
Boxcmninta omy omNoprsOll seer eps pon ei eeu ce OT a UN ee age 08 2 lle: 43
ihe absorption of arsenie by the growine plamt = 4s 9252..55.50. 2.2/2 43
iitpomme* sulphur as aasounce: OW aALSemiG.2 25.5 em ee Gos Oa +4
COT CHUST OM Seem aA Or None) POLE ER rs oR Mens IA Stal a ay 45 |
Apple leal-spot, caused-by sphaeropsis malorum:)2. 252.2225 2522222). 2. 7
JS EIROKG HORST am cls cy el A RR NR RS aA beara od er tani ie A re Te AT
OBES OE IGRI UO cate Poet eae seh as ieee: tees Or uuu amma Sy merenrran tA acc ne Mets. ee 48
Cuilinumalls tid Ves sree eee A Meike 6 Resets oe ss Ws isis Peegeme aseptic Oe! 49
Inoculatronvexperiments! | Sec2. s ieee Ge EN RE agate Pe ge bp 50.
(CHOTA HOSS GN MS eae cag ge Nee Rae oy eR AE eto SiC a ten age 52
SOMECSs Ole he CET Ine agape tn aaah = Ne le Soi SRE WS I emer a tek 52
ARSE NETO USTON SE sh Nec Seas gelato OR A eat Steel ont ac a Re 53
J BSN] GAG SEAHAM 0) FTAs oe, es mts SL cs ope ig ened SR A seer otic L's cece nn 7 1A a 54
The immunity of the Japanese chestnut to the bark disease....._._. ihe Sale pete 55
Mrerextentioithies barksdisease im: jen elma ma Reha Meese 2S 58
BNGHT pL PIATI ETD © VU Gays oes arta a ein pte ce IN oe eee aM NE Ie dd
Mr Hoaxes tees ooh 5 0 oho es eek aD penn Seem. ees Se 57
« The seven papers constituting this bulletin were issued in separate form on Jan-
uary 28, February 20, January 28, January 28, February 21, March 12, and February
10, 1908, respectively.
ial
oe)
LA STRATOS
PuatE I. Flowering branch of white snakeroot. (Hwpatorium ageratoides
i
1G OU
RY
i gs Oo) ease tae ae eay ene eed chia ane DNA oe et edge fs Sa A A ua
Floweri ing branch of mountain laurel ( Kalmia latifolia L.). - he oe
Fig. 1.—Apple leaves showing leaf-spots produced by aster hae.
tion. Fig. 2.—Apple leaves showing leaf-spots produced by
inoculation with Sphaeropsis malorum Pk . ....-.---------------
Fig. 1.—Unsprayed Winesap trees defoliated by the leaf-spot disease.
Fig. 2.—Sprayed Winesap trees in full foliage, located in the’ same
orchard and photographed at the same time (October 19, 1906) as
those’shown in figure Wi Soi o Se ee ee eee
121
+
Page.
14
22
48
52
B. P. I1.—356.
MISCELLANEOUS (PAPERS.
B. P. I.—21.
ie SUPPOSED RELATIONS TIE OF Wits SNAKE:
ROOT 10 MIILKSICKNESS, OR TREMBEES.
By Apert ©. Crawrorp, Pharmacologist, Poisonous- Plant Investigations.
¥ HISTORICAL INTRODUCTION.
Many of the early settlers of the Ohio Valley, especially in Indi
ana and Illinois, were affected with a peculiar disorder known as
milksickness, a disease which is said to have caused the death of.
Abraham Lincoln’s mother. Persons with this disorder usually
showed no mental disturbances save slight apathy, although late in
the course of the disease there might be coma.
Milksickness was usually characterized by vomiting, which might
be bloody, and obstinate constipation, but in rare cases this was
absent.’ So*marked was this constipation that the name paralysis of
the intestines was. once suggested for the disorder.° The abdominal
walls were retracted and the pulsations of the abdominal aorta could
thus be easily seen. Later in the course of the disease tympanites has
occurred.? The urinary secretion was diminished and the breath
took on a peculiar fetid odor which was considered pathognomonic.
@ One of the most serious diseases which formerly threatened the life of man
and beast.in the forested parts of the Ohio Valley and adjacent territory was
that known as milksickness, or “trembles.” Although of late years much less
trouble has been experienced, an occasional outbreak is reported.
In responding to a request that the United States Department of Agriculture
investigate an attack of milksickness occurring near Peoria, Ill., a favorable
opportunity was obtained-to test the widespread and persistent popular belief
that the plant known as white snakeroot (Hupatorium ageratoides L. f.) is
responsible for the trouble. ;
After a study extending through several months, Dr. Albert C. Crawford,
Pharmacologist, acting under the direction of Dr. R. H. True, Physiologist
in Charge of the Poisonous-Plant Investigations of this Bureau, has shown in
the results Summarized in this technical paper that the eating of the plant of
the white snakeroot by animals or man is not followed by the disease and that
there is probably no relation between them.—B. T. GaLLoway, Chief of Bureau.
6 Crookshank, N. On the ‘Sick Stomach” of the Western Country, or
Gastro-enteritis. Phila. Jour. Med. and Phys. Sci., vol. 12, p. 254, 1826.
© Dawson, J. Causes and Treatment of Milksickness. Proc. Med. Conven-
tion, Ohio, 1842, p. 48. Aki
id Wood, G. B. Treatise on the Practice of Medicine, vol. 1, p. 462, 1858.
121—1
5
|
EE. eee ee
6 MISCELLANEOUS PAPERS.
Associated with these symptoms were those of prostration, with rest-
lessness and great thirst. Pain was referred to various localities.
The temperature usually remained normal or was subnormal, rarely
exceeding 99° I’. At times it reached 100° F. There are, however,
very few recorded cases in which the temperature was actually meas-
ured by a thermometer. The. pulse remained about normal, but
might at times be accelerated. Nothing very characteristic was noted
concerning the tongue save that it was enlarged. In certain cases
difficulty in swallowing was reported; in others hiccough was a more
or less prominent symptom.? No reports were made as to the con-
dition of the pupil or of any ocular disturbances save an intolerance
of light.¢ | ;
There was said to be an incubation period of from two to ten days,/
although apparently some cases had no such period.’ The disease
itself usually lasted from two to twenty days, but chronic cases are
reported.” The disorder generally occurred in spring or autumn,
particularly in autumn, although it might appear at any season.'
The conditions which were especially favorable for its development
were said to be those which interfered with normal excretion.’ One
attack gave no immunity, but rather predisposed to a second one.*
The post-mortem ‘records are few‘in number. The only lesions
reported are those of irritation and inflammation of the’stomach and
@Kimmell, J. A. Milk Sickness in America. Verhandl. d. X internat. med.
Cone vols 2. pie OD; p= D4, 18915
bHurd, A. Milk Sickness. Clinic, Cincinnati, vol. 9, p. 280, 1875.—Way,
J. H. Clinical History, Nature and Treatment of ‘* Milk-Sickness.” Amer.
Jour. Med. Sci., n. s., vol. 106, p. 310, 1893.—Yandell, L. P. Inquiry into the
Nature of the Disease Called Milk-Sickness. West. Jour. Med. and Surg., 5 §.,
vol. 9, p. 393, 1852-—Drake, D. Memoir on the Disease Called by the People
“'Trembles.”” West. Jour. Med. and Surg., vol. 3, p. 178, 1841.
e Graff, G. B. On the Milk Sickness of the West. Amer. Jour. Med. Sci.,
ne Se VOSA Da oot bOaN:
@ Coleman, A. Observations on the Disease Generally Known by the Name of
the Sick Stomach. Phila. Jour. Med. and Phys. Sci., vol. 4, p. 325, 1822.
é Grait. G:>Bo1.-c, ‘p..354.
f Beach, W. M. Milk Sickness. Trans. Ohio State Med. Soc., vol. 38, pp. 181,
133, 1884.—Kimmel, J. A., l. @., p. 50.
a Mandela Pos Cs. eos
kYandell, L. P., 1. ¢., p. 392.—Kimmell, J. A.; 1. e:., p. 54.
* Byford, W. H. Milk Sickness. Nashville Jour. Med. and Surg., vol. 9, p.
467, 1855.—Yandell, L. P., 1. «, p. 379.—Beck, J. C. Milk-Sickness. North-
West. Med. and Surg. Jour., vol. 14, p. 497, 1857. é
J Philips, W. H. Milk Sickness. Cincinnati Lancet and Observer, vol. 38,
p.- 142, 1877.
& Philips, W. H., Iic.; p. 147.—Yandell, LL: Ps i. cp. soe:
121—1
ee. af
RELATIONSHIP OF WHITE SNAKEROOT AND MILKSICKNESS. (
-intestines,¢ as shown by hemorrhages into the lumen of these organs
and injection of their walls, with at times adhesion of the intestinal!
walls to one another.” The pyloric region was found contracted,’
and Peyer’s and Brunner’s glands were swollen. Graff has reported
in one case adhesions and thickening of the cerebral membranes.? In
other cases in which autopsies were made very slight lesions were
noted.° |
The clinical symptoms of some cases of milksickness resemble
closely those described by Vaughan and Novy under the name galac-
totoxismus’ and would probably be so diagnosed if they occurred
outside of the areas where milksickness is prevalent. Schmidt’ sug-
gested that cases of milksickness occurred in cities, but were not
diagnosed as such. Other cases resemble other forms of ptomaine
poisoning described by Vaughan,’ while the symptoms of still others
resemble those occurring in Van Ermengem’s cases of sausage pois-
oning. These cases described by Van Ermengem?‘ showed marked
nausea and vomiting and severe constipation, although two cases had
diarrhea. There was retention of urine, while the temperature, pulse,
and mental symptoms remained about normal, as in cases of milk-
sickness. Some difficulty in swallowing was noted and there were
ocular disturbances—diplopia, dilatation of the pupil, ptosis, ete.
The post-mortem examination, as in milksickness, showed no char-
*De Bruler, J. P. Milk-Sickness. Chicago Med. Jour., vol. 15, p. 209, 1858.
oDavis, K. H. Milk-Sickness. Atlanta Med. Reg., vol. 1, p: 394, 1881-82.
¢ Byford, W. H., 1. ¢., p. 465.—Drake, D. Morbid Anatomy of Milksickness.
West. Jour. Med. and Surg., vol. 4, 1841, p. 234.
@Eratt. Gs B. 1. ¢, p. 366:
]@rookshanks.-N:, 1:26) p.-256:
f Vaughan, V. C., and Novy, F. G. Cellular Toxins, 1902, p. 216. Compare
Graff, G. B., l. ¢, p. 8364; also Walker, J. W., Milk-Sickness, Science, vol. 8, p.
483, 1886.
9 Schmidt. C. H. Milk Sickness. Cincinnati Lancet and Observer, vol. 20, -
OMT Te k= :
tVaughan, V. C. Ptomaines, Toxins and Leucomains. Twentieth Century
Practice, vol. 13.
?Van Ermengem, EH. Ueber einem neuen anaerobd. Bacillus u. seine Bezie-
hungen z. Botulismus. Zeits. f. Hygiene, vol. 26, p. 1, 1897; Untersuch. ii. Fille.
vy. Fleischvergift. mit Symptomen y.. Botulismus. Cent. f. Bakter., part 1, vol.
19, p. 442, 1896.—Romer, P. Ein Beitrag z. Aetiologie des Botulismus. Cent.
f. Bakter., part 1, vol. 27, p. 857, 1900.—Kempner, W., and Pollack, B. Wirkung
des Botulismustoxins (Fleischgiftes) und seines specifischen Antitoxins auf die
Nervenzellen. Deutsch. Med. Woch., vol. 23, p. 505, 1897.—Brieger and Kemp-
ner, W. Beitr. z. Lehre von der Fleischvergift. . Deutsch. Med. Woch., 1897, p.
. 521.—Kempner, W. Weiterer Beitrag z. Lehre von den Fleischvergift. Das
Antitoxin des Botulismus. Zeits. f. Hygiene, vol. 26, p. 481, 1897.—Osler, W.
Modern Medicine, vol. 1, p. 232, 1907.
eee
8. MISCELLANEOUS PAPERS.
acteristic macroscopic lesion. From the spleen was isolated an ane-
robie bacillus which could reproduce the symptoms of the disorder
in animals. This organism, was found in various places in the meat
used in making the sausage. On culture media it developed an odor
of butyric acid. The toxin obtained from these cultures would re-
sist heating at 70° C. for a short time, but heating to 100° C. destroyed
it at once. Van Ermengem mentions that in cats injected with this
toxin there was muscular rigidity and that the ocular symptoms in
these animals were not marked. Dogs, however, were very resistant
to the action of this toxin. This organism has also been found in the
feeces of hogs. A similar outbreak occurred in Darmstadt after eating
vegetables infected with the same organism.“
No doubt the term “ milksickness” has been made to embrace a
variety of clinical conditions; in fact, there has been such confusion
in the reports that some authors, as Yandell, have denied its existence
as a peculiar entity.”
The mortality as given by Coleman ° is one death in ev ery twenty
or thirty cases. Others, as Mendenhall,’ allude to milksickness as a
“very grave disease”; others, again, speak of the outlook as favor-
able under the proper treatment.
In the same portions of the country in which milksickness peor’
a similar, if not identical, disorder also affected demestic animals,
especially cattle. In them muscular tremors were present and became
especially noticeable when the animals were driven, so that this dis-
order received the name of “trembles.”¢ It was also called the-
“ tires.” on account of the disinchnation of the animals to move. A
ngidity of the muscles has been noted by McCall.’ The post-mor-.
tem examination showed the gastric mucosa to be softened and the
stomach and intestines contracted,’ in some cases gangrenous,” and at
times there was more or less peritonitis. The odor developing at
a Fischer, Ay Ueber eine Massenerkrankung an Botulismus infolge Genusses
“ verdorbener ” Bohnenkonseryen. Zeits. f. klin. Med., vol. 59, p. 58, 1906.
Nore.—The bacillus Aeroganes capsulatus which occurs in the human intes-
tinal tract may give rise to infections associated with constipation. See Herter,
C. A., Common Bacterial Infections of the Digestive Tract, 1907, p. 207.
Yandel be. keep: ee ult J. F. Observations on Milk-Sickness.
Western Lancet, 1845, vol. 3, p. 4458.
Se Colemanw Ac se. ap: ae
@\Mendenhall, I. Milk-Sickness. Chicago Med. Jour., vol. 18, p. 485, 1861.
EsVandellvalas gee sere ae oo: fe
/MeCall, A. Facts and Observations on the Milk Sickness. West. Jour.
Med. and Phys. Sci., vol. 3, p. 467, 1830.
T Grati. GB. lee peroor.
“Dickey, W. Essay on Milk Sickness. Western Lancet, vol. 15, pp. 391-395,
1852
121—1
ee a ee
RELATIONSHIP OF WHITE SNAKEROOT AND MILKSICKNESS. 9
a
some of these autopsies was especially offensive and was compared
with the odor arising in mercurialism.* In one ease the cerebral
ventricles contained fibrin and the brain itself was surrounded by
serum and pus.2 The spinal cord in this case showed signs of in-
flammation. In other cases no special lesions were noted.°
It was proved that many cases of milksickness were communicated
to man by means of milk and its products? or meat? obtained from
cattle affected with the “trembles”; even the amount of cream
usually added to coffee is said to have induced the disease. Other
cases apparently arose without the products of diseased animals
being eaten, as by using contaminated water; / and, again, cases have
occurred in vegetarians." In some cases the fencing off of the sus-
pected springs from the pasture was followed by the disappearance of
“trembles ” from the neighborhood. The “trembles” still appear
at times, although much less common than formerly,’ its disappear-
ance being traced to the cultivation of the soil;/ and it is associated
with certain shady, sharply localized, wet, untilled areas. No char-—
acteristic geological peculiarity has been proved for these areas.”
Drake met the disorder almost entirely on oak plateaus, and especially
on the so-called “ slashes” or marshy areas.’ It is claimed that the
@ Drake, D., 1. c., p. 172.—McCall, A., 1. c., p. 467.
OGratt, G; 4B:, 1. ¢.,-p.. 363. ;
€ Philips, W. H. Milksickness. Cincinnati Lancet and Observer, vol. 20, p.
i288 Beach 1.e, p, 137. 4
@ Drake, D., l. c., p. 194.— Wilkinson, G. W. Etiology of Milksickness. North-
west. Med. and Surg. Jour., vol. 14, p. 156, 1857.—Townshend, N. S. Milk-
Sickness. Jour. Comp. Med. and Surg., vol. 4, p. 118, 1883.—Schmidt, C. H.
Milk Sickness. Cincinnati Lancet and Observer, vol. 20, p. 411, 1877.
€Yandell, L. P. Report on Milk Sickness. Proc. State Med. Soe. Kentucky,
p. 94, 1868. [Gives negative reports. |
i Graff,,G. B., 1. ¢c, p. 359.
9 Crookshank, N. Observations on the Milk Sickness, Cincinnati, 1840, p. 11;
Sick Stomack, Ohio Med. Rep., vol. 1, p. 11, 1826.
the Nature of the Disease Called Milk-Sickness, West. Jour. Med. and Surg., 3 s.,
vol. 9, pp. 383, 389, 1852.— Walker, J. W. Milk-Sickness. Science, vol. 8, p. 483,
1886.— Wilkinson, G. W., 1. ¢, p. 158.—Thompson, 8S. W. Milk-Sickness. West
Jour. Med. and Surg., 3 s., vol. 11, p. 480, 1853.—Jones, J. T. Short Essay on
Milk Sickness. Hast Tenn. Rec, Med. and Surg., vol. 1, p. 830, 1852-55.
TONES Ihe (Cen Ds 2O:
*Connor, J. J. Further Contribution to the Subject of Milk-Sickness. Chi-
eago Clinic, vol. 17, p. 383, 1904.
i Yandel, ti. Ps, lk e..p. 38%.— Walker, J. W., 1. ¢, 540: also Trans! Indiana
State Med. Soc., 1873-75, p. 128.
Norre.—Some areas are not entirely freed by cultivation. »
bYandell, 1. P:, lee. pe 319.
Norrt.—J. S. Seaton in his “Treatise on the Cause of the Disease Called by
the People the Milksickness,” p. 10, claims that he can pick out milksick areas
by the geological conditions. Bk
“Drake, D., 1. ¢., p. 184.
121—1
Vandel. 2a Inquiry inte,
= SS—S==
SS OSS —
FPS lll oEL—ESESeSSS——SESS
10 MISCELLANEOUS PAPERS.
disease is contracted by leaving the cattle in these areas over night
and that the disorder can be avoided by withdrawing them from
pasture before dark.* | Corn fodder experimentally exposed to the
dew in these areas communicated the disorder to a yearling.?
One of the peculiarities claimed for this disease is that cows will
show no-symptoms so long as they are milked, while their nursing
calves die with typical symptoms, but when the milking ceases the
cows develop the symptoms in the usual manner. In other words,
the poisonous agent 1s partially eliminated by the milk.“ The urine
is also claimed to eliminate a portion of the poisonous body.? The
suspected milk in some cases was noted to be of a greenish color,’
but usually there was no characteristic noted which is peculiar to it.? ©
The disease was apparently known to the early French mis-
sionaries in the eighteenth century, but accounts of it first appeared
in medical literature in 1809-10.2. They were numerous from 1840 to
1850, but now notices seldom appear.
The etiology of this disorder has remained in doubt, and Osler,"
in an address before the young medical officers of the United States
Army, mentions its causation as one of the many intricate problems
remaining to be solved. Rewards were at one time offered by several:
States for the solution of this question, but these do not hold at
present. Opinion has been divided as to whether “trembles,” or
milksickness, is of parasitic origin or due to the eating of certain
plants, as Rhus toxicodendron or R. venenata,' Bignona capreolata,
@ Beach, W. M. Milk-Sickness. Trans. Ohio State Med. Soc., vol. 38, pp.
128, 180, 1884.—Lea, W. W. Cursory Remarks on a Disease Vulgarly Called
Milk Sick. Phila. Jour. Med. and Phys. Sci., vol. 2, p. 51, 1821.—Way, J. H.,
RCs pseok2: /
6 Walker, J. W., 1. c., p..483.
¢Kimmell, J. A., l. c., pp. 50, 52.—Drake, D., 1. c., pp. 198, 200.—Graff, G. B.,
lhe KEIO OE BAO):
@Gratt, G. B.-1.°¢e:, p. 360: :
€ McCall, A. Facts and Observations on the Milk Sickness. West. Jour.
Med. and Phys. Sci., vol. 3, p. 467, 1830.
i Graff, G. B., 1. ¢, p. 359.
9 Drake, D., 1. c, p. 162; also West. Jour. Med. and Phys. Sci., vol. 3, p. 482,
1830.
Osler, W. Aequanimitas, 1904, p. 116.
¢ Landrum, Z. C. Rhus Toxicodendron, the Cause of Milk Sickness. Atlanta
Med. and Surg. Jour., vol. 7, A, p. 1, 1861.—Chase, S. C. Cause of Milk-sickness.
Chicago Med. Jour., vol. 18, p. 4388, 1861.—McIlhenny, J. J. Treatise on
the Disease Called the Milk-Sickness, Springfield, 1843, p. 6.—Nichols, J. H.
Milk-Sickness. Clinic, Cincinnati, vol. 10, p. 26, 18S76.—Brewington, W. J. Milk-
Sickness. Clinic, Cincinnati, vol. 10, p. 76, 1876.—Crook, J. W. Twenty Propo-
sitions on Milk-Sickness. North-West. Med. and Surg. Jour., vol. 14, p. 491,
1857.—Jones, J. T. Short Essay on Milk Sickness (Colica trementia). Hast
Tenn. Rec. Med. and Surg., vol. 1, p. 324, 1852-53.
121—1
fp
RELATIONSHIP OF WHITE SNAKEROOT AND MILKSICKNESS. iL al
Eupatorium ageratoides, Lobelia inflata, etc.¢ Graft? eliminated
arsenic, copper, etc., as causative factors and showed that small
quantities of the butter or cheese (1 ounce) or of the beef (4 ounces)
obtained from animals with the “trembles,” if fed to a dog three
times a day, would reproduce the symptoms in forty-eight hours and
cause death in from three to six days; but his inoculations failed to
produce the disorder. Graff adds that the poisonous principle seems
to possess the power of infinite reproduction, stating, “ It will be
found that each pound of flesh of that animal so destroyed will
possess as active powers of destruction, and will, in its turn, serve
to contaminate the whole body of another animal in the same degree.”
Vermilya ¢ claims that he was able to reproduce the disorder by feed-
ing Hupatorium ageratoides and that his experiments were corrobo-
rated by Rowe, but A. W. Bitting, of Lafayette, Ind., reported to
this Department his experiments in which he fed a horse 210 pounds
(105 kilos) of this fresh green plant in five days without serious
effect. He also fed two lambs with 80 pounds (40 kilos) without
effect. Similar experiments are reported by Drake.4 The theory
of a plant poison was emphasized, as herbivorous animals were sup-
posed to be the first affected and from them the disease transmitted
to the carnivora, although the cases do not always originate in
herbivora.°
a Jerry, W. The Plant that Causes Milk Sickness. Med. and Surg. Rep.,
vol. 16, p. 270, 1867.—Drake, D., |. ¢., pp. 2138—224.— Jones, J. T., |. ¢., p. 324.
e Gratt, G2 B., |: ¢., pp. 857, 360; 362.)
NoTtr.—Graff says the meat is active “raw or boiled,” but there is evidently
some mistake, as he states on page 361 that “I boiled a large quantity of the
beef in pure water for several hours, and afterwards evaporated the liquid
thus obtained to the consistence of creain. Although this extract contained
a large quantity of gelatinous matter, with some of the other constituents of.
the flesh, yet, on being given in large quantities, no perceptible effect was pro-
duced.”
Compton, J. W. Milk-Sickness. Indiana Med. Reporter, vol. 2, p. 255, 1881.
¢ Ohio State Board of Agriculture, 13th Ann. Rept. for 1858, 1859, p. 673.—
Barbee, J. W. Facts Relative to the Endemic Disease Called by the People of
the West Milk-Sickness. Western Jour. Med. and Surg., vol. 1, p. 182, 1840.—
Drake, D., 1: ¢:, p. 214:
Note.—The view that arsenic is the etiological factor in milk-sickness has
been strenuously upheld by Seaton in his Treatise on the Cause of the Disease
Called by the People the Milksickness. Louisville, 1841.
GDrake Doyle. pp, 2ip ot
Notrt.—The cases described by Barbee in the Western Journal of Medicine and
Surgery, vol. 1, p. 182, 1840, in which dogs were killed with decoctions of this
plant, seem to be merely cases of so-called salt action.
€Compare Jones, J. T., 1. ¢.,-p. 328. .
tte 1 i
12 MISCELLANEOUS PAPERS.
In 1843 Heeringen,* and later, in 1853, Heusinger,’ compared this
disorder to anthrax, and in 1858 Wood on purely literary evi-
dence argued the presence of “a germ.” © Byford? and De Bruler ¢
called attention to the fact “ that it undergoes multiplication in the
system ” and that it lost none of its virulence by passing through four
successive animals. Gardner‘ and Hessler / claim to have found para-
sites in the blood, while Philips” compares the organism seen by him
to that met with in relapsing fever. The examinations of the blood
made by Schmidt were negative.’ Molds and mushrooms also have
been claimed to be the etiological factors.’ No one has yet reproduced
the disease by injection of pure cultures of organisms.
The question thus remained in doubt, with the weight of evidence
in favor of a parasitic origin, when a paper by Moseley * appeared.
As his paper attributes the origin of this disorder to the eating of
Eupatorium ageratoides, or white snakeroot, it was deemed advisable
to analyze his evidence, as follows:
Experiment No. 1—This consisted in feeding a cat weighing
44 pounds (2,041 grams) with a solution made by extracting the leaves
of three or four (?) plants in one pint (473 c. c.) of milk. After
taking about one-half gill (59 ¢. c.) of this extract the animal showed
tremors and dullness and was found dead in about twenty-six hours.
The post-mortem examination proved to be negative. It is possible
in this case that bacteria may have developed in the milk and pro-
duced poisonous compounds before feeding. This experiment was
performed by Moseley’s assistant and the animal was not seen by him
until after death. ? :
Buperiment No, 2—A tramp kitten of unknown history weighing
30 ounces (850.5 grams) was fed with a decoction made from one-half
=
@ Heeringen, E. Discovery of the True Cause of the Disease Called by the
People Trembles, or Milksickness, Louisville, 1843.
6 Heusinger, C. F: Recherches de Path. Comp., vol. 1, p. 126, 1853.
€¢ Wood, G. B., 1.-¢., p. 465.
¢ Byford, W. H., 1. c., p. 467.
DeBruler, Je. 1. cep. 209:
f Gardner, J. Milk-Sickness. St. Louis Med. and Surg. Jour., vol. 38, p. 290,
1880. «
9 Hessler, R. Preliminary Notes on an Almost. Extinct Native Disease, Trem-
bles or Milk-Sickness. Proc. Indiana Acad. Sci. for 1905, p. 122.
PPh ps. wWe He leaped oo:
2 Schmidt) @F He 1Scx psy l2:
j Wilkinson, G. W.,-1. ¢.,. p. 159.—Howard, H. J.. Mukosma. Indiana Jour.
Med., vol. 2, p. 870, 1871.—Borland, S. Essay on the Milk Sickness, p. 27, Little
Rock, 1845.—Drake, D., 1]. ¢., p. 218.—Johnson, J. M. Milk-Sickness. Atlanta
Med. and Surg. Jour., vol. 7, B, p. 293, 1866. Compare also Mitchell, J. K., Five
Essays. ;
k Moseley, E. L. The Cause of Trembles in Cattle, Sheep, and Horses and of
Milksickness in People. Ohio Naturalist, vol. 6, pp. 463 and 477, 1906.
121—I
RELATIONSHIP OF WHITE SNAKEROOT AND MILKSICKNEss. 13
pound (226.8 grams) of the fresh plant and also some milk extract of
the plant, more of the plant than the first (a larger cat) received.
The cat was dull and showed tremors at times after the first feeding,
but the appetite remained good, and eleven days later trembling could
still be seen. Eighteen days later the animal was fed on the carcass
of a rabbit which had died after eating the same plant (see experi-
ment No. 6). This rabbit had died three days before the feeding of
the cat began. ‘Some tremors were seen in the cat, but it ate and con-
tinued active for three days, when it was killed. This experiment is
open to the objection that nothing was known of the cat previous to
the feeding, and cats often show shght tremulous movements of the
cutaneous muscles. Then again, granting that the tremors were due
to eating the meat, no record is made of having preserved the rabbit .
meat on ice, and decomposition may already have begun, and the mere
presence of muscular tremors of unknown origin without the other
clinical symptoms does not indicate the disease known as “ trembles.”
Eauperiment No. 3—A cat whose previous history was not given
was fed on the same carcass given to the cat referred to in experiment
No. 2, and on that referred to in experiment No. 7, after it had stood
two days, and the feeding was continued three days; then it was fed
on a similar rabbit two days after death. This animal showed tre-
mors and died in twenty days. The temperature of this animal rose
about 24° F. on the third day before death. The buttocks were re-
ported soiled, so evidently it had no marked constipation. Now, con-
stipation is a symptom which Kimmell, Drake, Chesney, Graff, and
others had previously noted in animals affected with the ‘“ trembles,”
and is one of the characteristics of milksickness.¢ -Post-mortem ex-
amination showed two ounces of acd fluid in the peritoneal cavity.
Hapermment No. 4—A cat which was sick before beginning the
experiment was fed with a milk extract of the plant, but only showed
light symptoms (diarrhea) and “ was seen to tremble only a few times |
and then under conditions which might probably have produced trem-
bling without the aid of any poison.” This animal was then fed on
meat from one of the rabbits used in previous experiments. Moseley
said that “ the meat seemed to affect him more than the milk.”
Kaeperiment No. 5—A dog was fed on an aqueous extract of the,
plant mixed with milk and some chopped-up plant mixed in hash and
showed some trembling and weakness, but Moseley adds ‘“* he was not
so different from usual except in the early morning but what all these
things might have escaped notice if he had not been watched.” In
other words, an animal which Graff had shown to be very susceptible
a@ Chesney, J. P.- Milk Sickness. St. Joseph Med. and Surg. Rep., vol. 1, p.
99, 1880.—Kimmell, J. A., 1. c, p. 51—Drake, D., 1. ¢.3 cow,. p. 170; horse, p.
173; dog, p. 174.— Graff, G. B.,1. c., -p. 360. |
121—1
14 MISCELLANEOUS PAPERS.
to the “ trembles,” when fed with Hupatorium ageratoides, the sup-
posed carrier of the disease, showed practically no symptoms. He
then adds the remarkable report of his assistant: ‘“‘ While I held the
dog’s mouth open a friend poured the extract into the dog’s mouth.
The dog choked and coughed the extract into my face and mouth.
I was in a room while the mixture was steeping and also on the pre-
vious evening. At 10.30 I was taken with a fit of cramps and the fol-
lowing day was nauseous. Several times during the three following
days I had fits of trembling, always accompanying the extension of
limb.” In this connection it may be stated that the present writer’s
laboratory assistant and himself squeezed their material by hand,
handled it, and made their own extracts.in a rather close room with-
out experiencing any such effects.
Laeperiment No. 6.—In this case 2 ounces (56.7 grams) of the
snakeroot was placed in the cage with a rabbit. The rabbit died in
three days. No tremors had been noted. This case can be excluded
because of the absence of any accurate clinical report or histological
examination, as rabbits are very apt to die of intercurrent diseases,
especially coccidiosis.
Eaperiment No. 7—This is of the same type as experiment No. 6,
and open to the same objection. Moseley merely quotes the report
of his pupil as to the presence of tremors.
Experiment No. $—This experiment consisted in injecting subcu-
taneously into a rabbit weighing 1,383 grams an aqueous extract of
3 grams of the plant. This injection was followed by tremors. Three
days later the animal was fed with 2 to 3 ounces (57.7 to 85 grams) of
the leaves and branches, and died in one hundred and twenty hours.
There was no constipation. Moseley says, ‘* The effects on her actions
end appearance were not striking and might have escaped notice if I
had not looked for them.”
Experiment No. 9.—A rabbit was fed for three days with an aque-
ous extract of the plant. The only result noted was a “ tremulous mo-
tion of the sides, with more rapid respiration.” This animal was then
fed with a milk extract of the plant. No constipation resulted, but the
same trembling was seen, and save for a slight lessening of strength
“she has seemed well.”
EHaperiment No. 10.—This experiment poneicted in feeding a milk
extract of the plant, but with only slight action. A rabbit was
reported to tremble after eating 67 grams of the leaves and branches
of a fresh plant, but survived.
Experiment No. 11—A young lamb weighing 40 pounds (18.14
kilos) was fed with the leaves of this plant. The animal showed
trembling and died in four days, having eaten about 29 ounces (822
grams). There was no constipation. The kidneys were found to be
a YP
Bul. 121, Bureau of Plant Industry, U. S. Dept. of Agriculture, PLATE Il.
FLOWERING BRANCH OF WHITE SNAKEROOT (EUPATORIUM AGERATOIDES, L. F.).
RELATIONSHIP OF WHITE SNAKEROOT AND MILKSICKNESS. 15
much enlarged, weighing about twice as much as normal. One can
form no positive opinion as to the cause of death. The enlarged kid-
neys, taken in connection with the history of convulsions and fluid
in the peritoneal cavity, might suggest a nephritis.
Six ounces (170 grams) of the liver of this animal were fed to
acat. This cat showed merely a few tremors.
[aa
=
N
—
S
jaa]
MOUNTAIN LAUREL, A POISONOUS PLANT. 23
Notices of this plant occur in the early botanies* and books of
American travel. Capt. John Smith describes, in his Generall His-
torie of Virginia, 1624, volume I, page 10, a “ Kinde of tree like
Lowrell,” while Hudson in 1609 mentions ‘“ rose trees ” as occurring
on Cape Cod. Catesby describes it under the name Chamaedaphne
foliis tint, floribus bullatis umbellatis, and says distinctly that “ When
cattle and sheep, by severe winters deprived of better food, feed on
the leaves of these plants, a great many of them die annually.” ’ The
Delaware Indians are said to have used a decoction of these leaves for
suicidal purposes.°¢
Publie attention was especially called to this plant by Peter Kalm,
the Swedish botanist, after whom Linneus named the genus Kalmia.
He described it under the name “ spoon tree,” because the Indians at
that time made spoons of this wood. During his travels in America
in 1748 he noted that calves which had eaten of the leaves became
“ sick, swelled, foamed at the mouth, and could hardly stand,” and
reported from the observations of the colonists that sheep, especially.
young ones, died very quickly after eating of these leaves, and that
horses, oxen, and cows were made sick but seldom died, as these ani-
mals ate only small quantities of the leaves. Deer and partridges
were said to feed on the leaves with impunity, and the venison from
these deer was harmless to man.? A snake was said to have been
killed by dropping a tincture of this plant on its back.¢
John Bartram, an early American botanist, was an ardent lover
of, and writer on, mountain laurel, and by him it was brought to
Collinson’s attention, who then introduced it into England about
1734.7 It would seem more appropriate to have named the genus
after him’ as his work antedated that of Kalm. During General
@Van der Donck, A. Vertoogh van Nieu Nederland, 1650. Translated by
H. C. Murphy, 1854, p. 19.—Plukenet, L. Almagest. botan., 1769, p. 106; Alma-
gest. botan. Mantissa, 1769, p. 49.—Gronovius, J. F., 1. ¢., p. 160.—Linnzus, C.
Spec. Plant., Ed. Willdenow, vol. 2,-p. 600, 1799. Spec. Plant., vol. 1, p. 393, 1753.
Ameen. Acad., vol. 3, p. 13, 1764.—Trew, C. J. Plante Selects, 1750, pl. 38.
Ray, J. Hist. Plant., vol. 2, p...1927, London, 1688. [Bannister’s list df
1680.]—Hudson, H. Discourse. Collections of the New York Historical Soci-
ety for the Year 1809, vol. 1, p. 121. ;
®Catesby, M. Natural History of Carolina, vol. 2, p. 98, 1743.
¢ Barton, B.S. Some Account of the Poisonous and Injurious Honey of North
America. Amer. Phil. Soc. Trans., 1802, vol. 5, p. 61.
qKalm, Ps Lc. pp. 264-265.
€ Barton, B. 8. Collections for an Essay towards a Materia Medica of the
United States, pt. 2, p. 27, 1804.
fAiton, W. Hortus Kewensis, vol. 2, p. 64, 1789.—Catesby, M., 1. c., p. 98.
9 Darlington, W.. Memorials of John Bartram and Humphry Marshall, pp.
130, 141, 228, etc., Philadelphia, 1849.—Bartram, John. Observations, London,
1751, pp. 26 and 69.
- 121—1rI
24 MISCELLANEOUS PAPERS.
Braddock’s campaign against the French and Indians in 1755 many
horses * were lost from eating mountain laurel. The plant was intro-
duced into France by Michaux.’ In 1802 George G. Thomas® per-
formed some experiments with /valmia latifolia and KK. angustifolia
on himself, on a friend, and on some dogs. These experiments he
embodied in an inaugural dissertation which was presented to the Uni-
versity of Pennsylvania. Six to 15 grains (0.4 to 1.0 gram) of the
dried leaves produced distinctly unpleasant symptoms—rapid pulse, a
feeling of fullness with pain in the head, throbbing of the temples,
with nausea, vomiting, and dilatation of the pupils. In dogs the
administration of a decoction of 30 grains (2 grams) was followed
by marked salivation, with stupor. rapid respiration and purgation,
paralysis, and finally convulsions. Thomas made the interesting ob-
servation that if the laurel was mixed with lard the toxic symptoms
were much lessened. He examined the distillate from the leaves for
an essential oil, but failed to find any.
After Thomas, several experimenters reported on the action of
mountain laurel upon themselves. Bigelow,’ who saw the dried
leaves taken- in doses up to 20 grains without producing symptoms,
questioned if the leaves had a specific action, and traced any injurious
effect they might exert to their indigestibilty. Others, as Osgood,¢
Stabler,’ and an anonymous author in the Boston Medical and
Surgical Journal, volume 10, page 213, reported severe symptoms on
themselves. 7 |
This action was compared with that of Veratrum.’ From this
time on few reports of experiments were published, yet the number
of cases of poisoning in stock reported to the Department of Agri-
- culture induced the Commissioner to call attention to this subject ,in
his report of 1863." Sheep are the animals usually reported as
affected by the plant. Under ordinary conditions, however, eastern-
bred sheep will not eat the plant unless they are starved or their
supply of green or attractive food has been cut off.
As is well known, most of the cases of poisoning occur in winter,’
when the laurel is the only green plant around, although western-bred
cBarton. B.S. 4:..c.p.-60:
‘Browne, D. J. Trees of America, p. 364.
e Thomas, G. G. Inaugural Dissertation on the Kalmia Latifolia and Angus-
tifolia, Philadelphia, 1S02.
4 Bigelow, J. Amer. Med. Bot., vol. 1, p. 140, 1817.
€ Bizelow, Ji, lec: VOl.-3;, Ps 185,01 820:
f Stabler, R. H. On Kalmia Latifolia. Amer. Jour. Pharm., n. Sok fp.
241, 1845.
g Medical Properties of the Kalmia Latifolia. Boston Med. and Surg. Jour.,
vol. 10, p. 218, 1834.
hk Report of the Commissioner of Agriculture for 1863, p. 242.
‘ Remarkable Instance of the Absence of Animal Instinct. Penny Magazine,
vol. 7, p. 283, 1838.
121—11
7 a ee
Cr
MOUNTAIN LAUREL, A POISONOUS PLANT. 2
sheep if suddenly turned into a laurel area may eat it at any time.
As the leaves are tasteless and of a tough, leathery consistency, it is
very evident why animals will not eat the plant under ordinary con-
ditions.
A good illustration of actual poisoning is given by Rusby “ where
out of a flock of 1,000 sheep which escaped into a laurel area, at least
27 showed symptoms of poisoning. Those affected were mainly the
young ones. In these cases the tracks on the snow around the bushes
and the presence of leaves in the stomach showed conclusively the
cause of the trouble. Halsted” reported poisoning in cows after
eating laurel wreaths which had been thrown from a cemetery into
their pasture. A striking case occurred in the National Zoological
Park, Washington, D. C., where six Angora goats were poisoned by
laurel thrown to them by visitors; later, a Diana monkey died with
typical symptoms after eating the leaves held to it by a visitor. The
_ leaves of the plant were found in the monkey’s stomach. The post-
mortem examination in this case was negative. Since these poison-
ings occurred visitors have been prohibited from carrying laurel into
the park.
Barton in 1802 °¢ called attention to the fact that the honey made
from Kalmia angustifolia was poisonous to man, and while no direct
proof? has been published that honey made from A’. latifolia is
poisonous it is perfectly logical to suppose that it is, as Plugge found
that honey made from Rhododendron ponticum, a closely related
plant, gave the same chemical and physiological tests on frogs and
mice which he considers characteristic of its active principle, androme-
dotoxin. Rhododendron ponticum is the plant which is supposed to
have yielded the honey which poisoned Xenophon’s‘ army. ,
Under these circumstances the Secretary of Agriculture advised
against raising bees in the neighborhood of mountain laurel. An
unpublished report is on file at this office of investigations in which —
extracts of mountain laurel were mixed with honey and fed to bees.
4Rusby, H. H. The Poisonous Properties of Mountain Laurel. Drug. Cir.
and Chem. Gaz., vol. 46, p. 27, 1902.
‘Halsted, B. D. WHighth Annual Report of the. New Jersey Agricultural:
College Experiment Station for 1895, p. 355, 1896.
¢ Barton, B. S. Some Account of the Poisonous. and Injurious Honey of
North America. Amer. Phil. Soc. Trans., 1802, vol. 5, p. 59.
@ American Bee Journal, 1896, pp. 92, 146, 246, 262.—_Root, A. I. A B C of Bee
Culture, p. 249.—Honey from Mountain Laurel.. American Bee Journal, vol.
35, p. 825, 1895. tae
© Plugge, P. C. Giftiger Honig von Rhododendron ponticum. Arch. d. Pharm.,
vol. 229, p. 554, 1891.—Thresh, J. C. Notes on Trebizonde Honey. Pharm.
Jour. and Trans., 1887-88, vol. 18, pp. 397, 404.
/ Pliny. Nat. Hist. (Translated by Bostock and Riley), VOL, 45 0. Veto)
bott, K. E. Letter, in Proc. Zoolog. Soc. London, pt. 2, p. 50, 1834.
121—11
26 ’ MISCELLANEOUS PAPERS.
The name of the investigator can not now be ascertained. These bees
are said to have shown no symptoms, but the honey they made pro-
duced typical symptoms in two persons who ate it.* It has been
claimed that the flesh of birds after eating laurel is poisonous to
man,’ but Wilson,’ Audubon,’ and Aaron ® state that they have fre-
quently eaten without-injury partridges whose craws were filled with
laurel leaves and buds. It is probable that many of these cases of
poisoning were really due to ptomaines, as they usually occurred
from undrawn animals.
There are few cases in man of poisoning with laurel. Children are
said to have been poisoned by eating the plant in mistake for Gaul-
theria procumbens,’ although there are no published cases to that
effect. Laurel is claimed to be used in certain hquors to render them
more intoxicating.’ Barton” noted that the flowers of Aalmia lati-
folia would produce a vesicular eruption in certain persons.
EFFECT OF MOUNTAIN LAUREL ON SHEEP.
Stable-fed sheep and lambs were turned into an inclosed area in
which the mountain laurel was the only green plant. These sheep,
which were kept under observation for several hours, refused to do
more than merely nibble at the leaves, and when placed in grassy areas
where this plant was growing they positively refused to touch it.
These observations agree with those of Wood‘ on Kalmia angusti-
folia. Other animals besides sheep seem disinclined to eat it. Kalm
reported in 1754 that the leaves of the trees in Pennsylvania were de-
voured by a worm, but that the mountain laurel leaves were un-
touched./
Sheep weighing about 50 pounds (25 kilos) were fed with doses
of 5, 10, 15, 25, and 35 grams of the dried ground-up leaves in-
closed in gelatine capsules without producing poisonous symptoms.
Fifty grams, when given to a sheep weighing 33.5 kilos, induced a
staggering gait and slight salivation, but doses of 85 grams would
cause death in a very few hours unless diarrhea set in. Under these
4@Unpublished answer to inquiry. See note on page 35.
> Barton, B. S., 1. e., p. 60.—Elliot, D. G. ‘“‘ Game Birds” of the United States.
Report of the Commissioner of Agriculture for 1864, pp. 363, 864, 1865.
¢ Wilson, A., and Bonaparte, C. L. Amer. Ornithology, vol. 2, p. 319, Edin-
burgh, 18381.
@ \udubon, J. J. Birds of America, vol. 5, p. 79, 1871.
¢ Aaron, C. KE. ~Cram’s Magazine, vol. 2, p. 502, 1900:
/ Unpublished correspondence.- (G. Watkins, 1896. )
9 Chesnut, V. K. Principal Poisonous Plants of United States. U. S. Dept.
Agr., Div. Bot. Bul. 20, p. 45.
t Barton, B. S. Collections for an Essay Towards a Materia Medica of the
United States, p. 35, 1804.
‘Wood, T. F. Is Sheep Laurel Poisonous to Sheep? American Agricul-
turist, vol. 42, p. 66, 1883.
I KalmeP) ae yolbmaap. 5266:
121—1r
MOUNTAIN LAUREL, A POISONOUS PLANT. 27
conditions sheep have survived this dose. In starved animals no
doubt smaller doses would be poisonous.
One experiment was with a sheep about 7 years old; weight about
5 kilos. On June 1, 1905, at 11:05 a. m., the temperature“ was
104.5° F., respiration 60, pulse 90 per minute. A slight secretion from
the nostrils was present owing to a coryza; pupils about one-fourth of
an inch wide; the conjunctival, buccal, and mucous membranes nor-
mal. Eighty-five grams of powdered dried laurel leaves in sealed
gelatine capsules were given. The feeding lasted twenty-five
minutes. |
Following the administration of the capsules little inclination to
eat was manifested, urination and shght defecation taking place dur-
ing the first hour. At 1 p. m., respiration was 110 per minute, pulse
117, temperature 104° F. Marked disinclination to move was shown,
the sheep permitting itself to be easily turned on its side. It ate onl
sparingly. Two hours after taking the laurel leaves urination was
repeated and slight emesis set in, followed soon by mental dull-
ness, as shown by decreased attention to surrounding objects, with
a loss of alertness, while the face took on a sleepy appearance and
saliva began to accumulate about the mouth. Respiration was some-
what labored and the unsteadiness in gait became marked. Two and
three-fourths hours after eating the laurel the sheep assumed an
awkward attitude in standing, the hind legs being set wide apart.
Repeated emesis became a prominent feature and continued for about
an hour, the ejecta being thin and mustard-like. Apparently to facil-
itate breathing, the mouth was kept open most of the time. Weakness
and unsteadiness increased until three and one-fourth hours after eat-
ing the laurel. At this time it was difficult for the animal to stand.
At 2:46 p. m. the temperature was 107° F., respiration 50 per min-
ute, pulse 124. The pupils were of the same size as before the feeding.
The abundant nasal secretion at this time became a very marked:
symptom, and continued so throughout the history of the case.
Weakness increased until the animal could not stand, and a dimin-
ished sensitiveness to skin irritation was noted. Death ensued
quickly at 3:06 p.m. No convulsions were noted at any time.
The post-mortem examination was made at once. The sheep ap-
peared to be well nourished. Some mustard-colored ejecta were
found in the trachea as well as in the bronchioles. The lungs crepi-
tated markedly, but showed no special amount of fluid. The pleural
cavity contained no increased amount of fluid. The mucous mem-
branes were not discolored. The heart contained no clots, was not
dilated, and contained only a little dark blood. The stomach was full
of food ae its walls showed no signs o irritation. se intestines
“Jn all cases the fapern cane was taken Oe the rectum,
121—11
28 MISCELLANEOUS PAPERS.
were apparently congested, but showed no hemorrhages. The small
intestines were more or less filled with thin normal-looking contents.
The kidneys appeared normal, the bile was of a dark-green color, and
the bladder was contracted and empty. The central nervous system
was not examined.
The bile from this sheep, which amounted to about 20 ec. ¢., was
treated with alcohol, and after evaporating off the alcohol in vacuo
was precipitated with lead acetate. The filtrate when freed from
lead by H,S and injected into guinea pigs produced absolutely no
symptoms characteristic of laurel poisoning.
On May 22, 1905, one of the yearlings previously used, weighing
24.5 lalos (49 pounds), was fed with 90 grams of powdered dried
laurel leaves in sealed gelatine capsules, the feeding beginning at
11:15 a. m. and taking about fifteen minutes. Before feeding, the
pulse was 135, respiration 50 per minute, rectal temperature 103.9° F,
After forty-five minutes an increased secretion of saliva became evi-
dent about the mouth and the sheep nibbled slightly at the grass. At
1:15 p. m. the temperature was 105° F., the head was held low, respi-
ration was somewhat labored, and saliva ran profusely from the
mouth; pulse 104, respiration irregular, 144 per minute, pupils un-
changed. ‘Two and a quarter hours after feeding, the animal became
less active, the ears were held back, and the general aspect was that
of a sheep half asleep. Respiratory and salivary symptoms. contin-
ued, the animal standing with the hind legs wide apart and showing
evidence of weakness in the hind quarters by a staggering gait.
Four hours after feeding, profuse nasal secretion became a con-
spicuous feature and weakness increased to such a degree that the
subject was unable to stand; respiration 120, temperature 104° F.
The nostrils were moist; pupils normal. Convulsions soon appeared,
with sensitiveness to touch persisting in the ‘conjunctiva; knee jerks
active, pupils a trifle dilated. Ten minutes later emesis followed.
Respiration was apparently increasingly difficult. The hind legs
seemed stiff. At 3:50 p. m. the pulse was 104 per minute, temperature
103.8° F., with continued attempts at emesis and repeated tossing of
the head from side to side; pupils normal. Death ensued at 9:30 p. m.
No discoloration of the mucous membranes was noted, and con-
stipation prevailed during the period of observation. At no time was
a marked thirst shown. The post-mortem examination made the fol-.
lowing day showed the trachea injected and very moist and two or
three teaspoonfuls of pure serum in the pleural cavity. The lungs
were cedematous. The auricles were relaxed and filled with black
clots; the left ventricle contained very little black blood, while the
right ventricle contained very much more. The abdomen was dis-
tended with gas. The stomach was partially filled with food; the.
second and third stomach walls showed no special lesions, but
121 .
Il
-— wise eS.
MOUNTAIN LAUREL, A POISONOUS PLANT. | 29
the intestines throughout showed marked hemorrhagic enteritis.
The small intestines contained very little solid matter, but there was’
some well-formed fecal matter in the coeccum. The liver was perhaps
a trifle pale and the kidneys were slightly injected. ‘The spleen
showed no macroscopic change. In none of these cases was it pos-
sible to secure the urine for examination, as the bladder was found
empty.
On October 14, 1905, a five-year-old (?) sheep, having a tempera-
ture of 101.8°F., at 1:20 p. m. was given 90 grams of fee laurel leaves
ground up nad mixed with meal.. The ration was practically all
eaten at 3:20 p.m., when the temperature stood at 104° F. At 6 o’clock
on the next morning a failure of appetite, together with slobber-
ing, was noted. Numerous soft stools were found in the pen during
the day. At 10:12 a. m. increased salivary secretion produced a frothy
‘appearance about the mouth ‘and the sheep held its head low. At 2:15 _
p. m. shght emesis and marked secretion of nasal mucus occurred ac-
companied by a temperature of 103.5° I. Twenty-five hours later
the slobbering had ceased, but the appetite had not returned and
the temperature stood at 102.9° F. Twenty-two hours later
(1:45 p. m., October 17) the temperature was 103.5° F. and the ani-
mal seemed normal. The presence in the pen of numerous soft stools
was noted. The sheep recovered.
EFFECT OF MOUNTAIN LAUREL ON RABBITS.
On February 6, 1905, a rabbit weighing 2,096 grams received
hypodermically one drop of aqueous extract of laurel (1 gram of
dried leaves in 3.75 c. ce. of water). Further administrations were
made as follows: February 13, 2 drops; February 21, 3 drops; Feb-
ruary 25, 4 drops; February 28, 6 drops; March 3, 9 drops; March
7, 12 drops; March 10,.14 drops; March 22, 20 drops. On the last
date evidence of laurel action appeared and a slight loss of appetite |
was noted. On March 30, 25 drops were administered as before, fol-
lowed on April 5 by 30 drops. At this time the animal weighed
1,828.5 grams. At 9:49 a. m. the temperature was 100.9° F., the ad-
ministration of the extract following three minutes later. The
resulting events were as follows: 10:05 a. m., mouth moist; 10:50
a.m. convulsions; 11:15 a. m., could not stand; 11:55 a.m., could
sit up in usual posture; 1:54 p. m., appeared normal. At 3:50 p. m.
the temperature was 103.3° F. The animal lived about a year after
the close of this investigation.
A rabbit weighing 1,599 grams, which had not received any pre-
vious injections, was given hypodermically at 9:54 a m., April 5,
1905, 30 drops of the extract used in the preceding case. The tem-
perature five minutes before administration was 100.8° F. The fol-
lowing symptoms developed rapidly: After nine minutes, interfer-
ae
30 MISCELLANEOUS PAPERS.
ence with the gait, followed shortly by urination and increasing evi-
dences of weakness, with marked difficulty in standing, was noted;
slight convulsions were seen 35 minutes after administration, repeated
at intervals during the following hour and a quarter; at 11:15 a. m.
paralysis of the hind legs led to a straddling attitude, head held back,
and sphincter relaxed. The temperature at 11:50 a. m. was 95.2° F.
At 1:54 p. m. the animal was much better. It could walk but stag-
gered. At3:49 p.m. the temperature was 102.3° F.; condition good.
The rabbit seemed apparently all right until April 13, when convul-
sions occurred which were followed by death.
GENERAL SYMPTOMS OF POISONING.
The symptoms commonly observed are salivation, tearing, an in-
creased flow of secretion from the nose, emesis with convulsions, and
later paralysis of the limbs. On post-mortem examination the main
macroscopic lesion is dilation of the vessels of the intestinal walls,
and if the case is not too acute, hemorrhages into the intestinal walls
occur, resembling what is known as rhododendron poisoning. The
aqueous extract of the flowers produced the same symptoms on rabbits
as that made from the leaves.
ACTIVE PRINCIPLE.
Comparatively httle chemical work has been done with mountain
laurel save testing for a volatile 011’ and arbutin.© Most of the chem-
ical work has been done on a closely related plant, Andromeda
japonica, now known as Pieris japonica. EKykmann®@ isolated an
amorphous glucosidal body which he called asebotoxin, which melted
at 120° C. and had a lethal dose for rabbits of 3 mg. per kilo. Plugge °
studied the same plant, making his first report in 1882. He extracted
the plant with water, then precipitated with lead acetate and lead
subacetate, and after removing the lead with sulphureted hydrogen
or sodium sulphate concentrated the fluid in vacug@at 50° C. This
colorless fluid was then shaken out with chloroform, and the chloro-
form on evaporation left transparent, noncrystalline scales, which he
called andromedotoxin. The mother liquid gave an amorphous
“Tn one case of poisoning by Andromeda polifolia, this was noted by Plugge.
Ueber d. Vorkommen d. Andromedotoxins in Andromeda Polifolia. Arch. d.
Pharm., vol..221,. p, 814; 1883.
6 Stabler R. H. On Kalmia Latifolia. Amer. Jour. Pharm., n. s., vol. 10, p.
246.—Bullock, C. On Kalmia Latifolia. Amer. Jour. Pharm., n. s., vol. 14, p.
260, 1848.
© Kennedy, G. W. Arbutin in Kalmia Latifolia. Amer. Jour. Pharm., vol. 47,
Da Del ouae
@Wykmann, I. F. Sur le Principe Toxique de Andromeda Japonica. Rec. d.
Travaux Chim. des Pays-Bas, vol. 1, p. 224, 1882. Phytochem. Notizen u. einige
japan. Pflanzen. Abhandl. d. Tokio Daigaku, No. 10, p. 1, 1883.
€ Plugge, P. C. Ueber Andromedotoxin. Arch. d. Pharm., vol. 221, p. 1, 1888.
121—IlI
MOUNTAIN LAUREL, A POISONOUS PLANT. 31
body, andromedorubrin. This andromedotoxin gave no precipitates
with alkaloidal reagents and did not reduce Fehling’s solution, but
gave certain color reactions and produced distinct and characteristic
symptoms on injection into guinea pigs and frogs—severe retching,
which, however, is absent after large doses; disturbances of respira-
tion; convulsions, and paralysis.
The characteristic color reactions are as follows:
(1) Concentrated sulphuric acid gives a dark reddish brown color
and dissolves it gradually. On warming it becomes a deeper red.
On dilution with water this passes into a light mulberry-red, disap-
pearing with alkalis returning with H,SO,.
(2) Evaporation with dilute H,SO, (1:5) on water bath causes
rose-red color. If the body is pure there is no odor, but if not pure
_ there is an odor of ericinol, due to the decomposition of ericolin, an
attached body.
(3) Dilute HCl acts the same as H., SO,, only it gives a color more
nearly violet-red.
(4) Dilute phosphori ic acid, 25 per cent, gives a mulberry-red color.
By this means 0.0000005 gram of ancromedotosin can be recognized.
Especial emphasis is. laid on the second and fourth reactions.*
Plugge also extended his studies to other members of this group. The
first of these to be examined was Andromeda polifolia. He made the
plausible claim that because the chloroform “ shaking ” from the aque-
ous extract freed from extraneous matter by lead gave the same color
reactions and produced the same action in animals as that from
Pieris japonica it contained the same active principle, but he admitted
that this body was much less active than the andromedotoxin obtained
from Preris japonica. He explained this weakness as being due to
the fact that the plant was grown on a different soil and that the
active principle varied from that of Pieris japonica much as the
active principle of the various species of Digitalis and Aconitum
vary.°
In using this method with Leucothoe catesbaec* Plugge noted that
the first six or seven chloroform shakings gave an amorphous residue,
while the seventh to the ninth gave a white crystalline body from
which he obtained the characteristic physiological action and color
reactions of andromedotoxin.
From Chamaedaphne calyculata he obtained some crystalline de-
posit, but in this case from the lack of material was unable to
@Plugge, P. C. Vorkommen von Andromedotoxin in verschied. Fe ae
Arch. d. Pharm., vol. 223, p. 906, 1885.
© Plugge, P. C. Ueber d. Vorkommen d. Andromedotoxin in Andromeda Dae
folia. Arch. d. Pharm., vol. 221, p. 818, 1883. '
¢Plugge, P. C. Vorkommen von Andromedotoxin in veneemie ws Ericaceen,
Arch, d. Pharm., vol. 228, p. 905, 1885.
32893—Bul, 121—08-—3_
a7 MISCELLANEOUS PAPERS.
positively identify it as crystalline andromedotoxin. The material.
obtained from this plant was less active physiologically than that
obtained from Preris japonica. Crystals were also obtained from
Azalea indica.
In 1887 Plugge ¢ and his pupil de Zaayer ® made a more extended
study of the andromedotoxin obtained from Lhododendron ponticum.
They summed up the previous chemical work and studied the active
principle pharmacologically. They claimed that the body shaken out
by the chloroform could be precipitated from alcohol or chloroform
solution by ether in the form of crystalline needles. Muto failed to
obtain these needles from Pieris japonica, the plant Plugge first
worked with. This body contained carbon, hydrogen, and oxygen,
but no nitrogen, and melted at 228° to 229° C. Plugge and de Zaayer
gave it the empirical formula -C,,H,,O;,, although the figures for
this conclusion were not exact.. It was readily soluble in water and
alcohol, but very slightly in ether. They stated that it was more
soluble in cold than in hot water, although Plugge elsewhere states
the opposite. In water, alcohol, and amyl alcohol it turns the plane
of polarization to the left, while dissolved in chloroform it turns it
to the right. It gives no precipitate with alkaloidal reagents. When
subcutaneously injected, 0.0001 gram caused death in a frog (Rana
temporaria) in a few hours.
This conjoint paper apparently so settled the question as to indi-
cate that all that was necessary to determine the presence of andro-
medotoxin was to ascertain if the chloroform shaking from the plants
gave the same physiological action and the same color reaction as
that described for andromedotoxin. Plugge did this with A’almia
latifolia and from its action on frogs decided that the fluid extract
contained one-half of 1 per cent of andromedotoxin. By this method
he decided that andromedotoxin was present in the following plants:
Rhododendron ponticum L.
Andromeda polifolia L. Rhododendron chrysanthum I.
Leucothoé catesbaei (Walt.) Rhododendron hybridum Wer.
Gray. Rhododendron falkoneri Hook. f.
Chamaedaphne calyculata (1..) Rhododendron maximum Ti
Moench. Kalmia latifolia I.
Pieris japonica Thunb.
Rhododendron grande Wight.
Rhododendron barbatum Wall.
Rhododendron fulgens Hook. f.
Rhododendron cinnabarinum
Kalmia angustifolia lL.
Azalea indica IL.
Monotropa uniflora 1.
Pieris formosa Don.
Hook. f.
Rhododendron puniceum Roxb.
Pieris ovalifolia Don.
*Plugge, P. C. Ueber Andromedotoxin. Arch. d. Pharm., vol. DOAS DS Aes
1883.
> Zaayer, H. G. de. Untersuch. ii. Andromedotoxin. Arch. f. gesam. Physiol.,
vol. 40, p. 480, 1887.—Plugge, P. C. Andromedotoxin. Verhandl. d. X internat.
med. Cong., vol. 2, pt. 4, p. 28, 1891.
121—II
re
MOUNTAIN LAUREL, A POISONOUS PLANT. Bs)
Plugge concluded that andromedotoxin was the active principle of
the Ericacee in general. | |
In the case of Rhododendron hirsutum, Plugge®* found that the
chloroform shaking failed to produce any immediate symptoms in
frogs, but three hours after injection convulsions with slight respira-
tory disturbance occurred, with the secretion of mucus from the
mouth. These symptoms completely disappeared, differing from those
of andromedotoxin. This extract gave no reactions with dilute or
concentrated HCl, 25 per cent phosphoric acid, and dilute H,SO,.
In studying the distribution of andromedotoxin, Plugge makes the
interesting observation that concentrated solutions of L'rica vulgaris,
now known as Calluna vulgaris, injected subcutaneously into frogs
cause symptoms resembling those of andromedotoxin poisomng, yet
‘chemically no trace of nie bedy could be found.?
Lasché also studied the action of extracts of Halmia latifolia and
K. angustifolia on animads, and corroborated Plugge’s data, but
isolated no pure body and made no chemical analysis. He used the
berries in his work.¢
Matusow,’ while accepting the belief that andromedotoxin is the
active principle of the leaves, says that the chemical reactions of the
root correspond with those of andromedotoxin, except with hydro-
chloric acid. He claims the presence of calcium, magnesium, alumi-
num, manganese, and iron in the roots.
icelnmpoleley examined another member of the Ericacee. the
Rhododendron chrysanthum, a native of Siberia, and isolated a crys-
talline principle, rhododendrin, with the empirical formula C,,H.,.,O,,
which was inactive to frogs, and a crystalline body, rhododendrol,
which acted on frogs similarly to camphor. He also claimed the
presence of andromedotoxin,. but did not isolate it. He examined
Rhododendron ponticum and obtained the same color reactions and
physiological reactions found by Plugge with andromedotoxin.
@Plugge, P. C. Andromedotoxinhaltige Ericaceen. Arch. d. Pharm., vol. 229,
p. 553,. 1891.
5 Plugge, P. C. Fortgesetzte Untersuch. ti. d. Verbreit. d. Andromedotoxins in -
d. Familie d. Ericaceen. Arch. d. Pharm., vol. 27, p. 171, 1889.
¢ Lasché, A. J. M. Peoiination of Some of the Poisonous Ericacee of North
America. Pharm. Rund., vol. 7, p. 208, 1889.
@Matusow, H. Analysis A the Root of Kalmia Latifolia. Amer. Jour.
Pharm., vol. 69, p. 341, 1897.
° Archangelsky, K. Ueber Rhododendrol, Rhododendrin und Andromedotoxin.
Arch. f. exper. Path. u. Pharm., vol. :46, p. 313, 1901.
121—IlI
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34 MISCELLANEOUS PAPERS.
Hayashi and Muto failed to obtain crystalline andromedotoxin
from Pieris japonica by using Plugge’s method.
So it can not be said that the active principle from mountain laurel
has been actually isolated in a pure state. Using Plugge’s method,
the writer failed to obtain active crystals from mountain laurel, but
obtained crystals by a different method, namely, from the filtrate
after ether precipitation. Plugge’s principle is precipitated by ether.
In no case has the writer found the ether precipitate physiologically
active, and an ether extract of the crude plants possessed the toxic
action of the plant. Full details as to the chemical and pharmaco-
logical investigations will be made later.
Laboratory animals, as guinea pigs and rabbits, after subcutaneous
injection show tearing, retching, convulsions, and later paralysis.
This physiological reaction can be used as a guide in the isolation
of the active principle. Before death in males there is an ejection of
semen.
REMEDIAL AGENTS.
The fact that sheep which have diarrhea have recovered from toxic
doses of mountain laurel would suggest purgative treatment.
Farmers very commonly administer lard in this condition, and this
no doubt acts by hindering absorption. The use of lard in laurel
poisoning has been substantiated by the experiments of Thomas, who
found that the animals were less likely to become poisoned if lard
was administered. In case vomiting and purgation do not occur.
this result should be encouraged by the usual agents.2 To induce
vomiting, 60 milligrams of apomorphine hydrochlorate may be given
subcutaneously and purgation may be encouraged by giving 2 to 6
ounces (60 to 180 grams) of epsom salts dissolved ‘in water as a
drench. The treatment is purely symptomatic and no true antidote
is known.
It seems of interest to ascertain whether the action on the glandular
secretion noted can not be obtained free from great toxicity by a
change in the chemical structure of the active principle.
MEDICINAL ACTION.
Thomas treated one case of diarrhea by means of a decoction of
Kalmia latifolia, and the leaves have also been used empirically in
the treatment of certain stages of fever. Locally an ointment has
@ Hayashi, H., and Muto, K. Ueber Athmenversuche mit einigen Giften.
Arch. f. exper. Path: u. Pharm., vol. 47, p. 220, 1902.
6’ Remarkable Instance of the Absence of Animal Instinct. Penny Magazine,
VOI Ms Deo, elooe:
121—II
MOUNTAIN LAUREL, A POISONOUS PLANT. 35
been employed for various forms of skin diseases, such as tinea, etc.,
but now it has fallen entirely out of use. Gosio, B. Atti r. Accad. Lincei, vol. 15, pp. 780-731, 1906; abstract in Centbl.
Bak. Par. u. Infek., part 2, vol. 18, pp. 724-725, 1907.
¢ Riiffer. E. Wochenschr. f. Brauerei, vol. 18, p. 109, 1901.
121—Iy
SOURCES OF ARSENIC IN DRIED HOPS. 45
of the same lot in which all the hops were grown and dried under
practically the same conditions, and also in samples drawn from dif-
ferent portions of one and the same bale.
This apparent contradiction may be explained on the assumption
that the arsenic volatilized by the burning of the sulphur is deposited
on the layers of hops next the floor of the kiln while the upper layers
remain practically free. To test this theory, a series of experiments
was made with a small kiln in which different lots of hops were sepa-
rately exposed to the fumes of equal amounts of the different grades
of sulphur, after which samples were carefully taken from the top
and bottom layers before the hops were removed. The experiment
was repeated with double the quantity of each grade of sulphur used
before. For comparison, a certain quantity of arsenious oxid was
added to the sulphur, with which a final lot was treated.
The preliminary results of these experiments fully support the
theory that arsenic may be transferred from sulphur to hops and |
unequally distributed therein. The analysis of the samples shows
in practically every case a very appreciable difference between the
amounts of arsenic deposited in the upper and lower layers of the
hops. The evidence further indicates that the greater portion of the
arsenic 1s deposited in the bottom layer. The variation in the results
obtained with the different grades of sulphur was less than was an-
ticipated, since each grade apparently increased materially the arsenic
content of the hops.
Although each test was repeated, using double the amount of sul-
phur, the relative proportion of arsenic present was not constant.
However, the results indicate that a larger arsenic content may be
expected when the proportion of sulphur used is increased.
The samples from the last experiment, in which arsenious oxid (the
white arsenic of commerce) was added to the sulphur, contained rela-
tively large quantities of arsenic, twelve times as much being found
in the hops of the bottom layer as in those of the top layer.
CONCLUSIONS.
From the foregoing experiments the following conclusions are
drawn |
(1) Thnets of arsenic may occasionally be found in dried hops
irrespective of their geographical origin.
(2) If available arsenic is present in the soil it may be taken up
by the hop plant under favorable conditions.
(3) Except in rare cases the amount of arsenic derived from aie
soil by the hop plant 1s probably smaller than 0.01 grain per pound
of dry hops, which is the smallest amount regarded as deleterious by
the Royal Commission on Arsenical Poisoning in England.
L211,
46 MISCELLANEOUS PAPERS.
(4) By the use of impure sulphur during the process of curing,
hops may be contaminated with arsenic, which will be concentrated
in the lower layers on the kiln floor with the result that certain sam-
ples may show an amount greater than 0.01 grain per pound.
(5) The probability of hops acquiring arsenic from what seems to
be a very ready source may be much lessened by employing only the
very highest grades of purified sulphur in hop curing, and the quan-
tity used should be reduced to the lowest possible limit.
121—Iv
[eee ee a ee ee ee eee
‘
ee eS
B. P. I.—342.
GeLE LeAy- SrOP CAUSED Bi SPEAE
ROPSIS MALOKUM.
By W. M. Scort, Pathologist, and JAMES B. Rorer, Assistant Pathologist,
Investigations of Diseases of Fruiis.
INTRODUCTION.
The disease of apple leaves known as “ brown-spot,” “ frog-eye,”
“ leaf-blight,” or “ leaf-spot ” is very common throughout the eastern
United States. As these. names suggest, the disease is characterized
by circular or irregular reddish brown spots with shghtly raised
purplish margins. (PI. III, fig. 1.) These spots when first visible
to the naked eye are very minute and purple, but rapidly increase in
size until they attain a diameter of from one-eighth to one-half inch,
while the affected tissue becomes brown and later sometimes gray.
The mature spots are usually circular, but after midsummer may be-
come more or less irregular or distinctly lobed in outline, a condition
apparently brought about by a secondary extension of the disease
from two or more points on the margin of the original circular spot.
If the infection is bad, a number of spots may coalesce and form
large brown patches involving half the leaf or more, but in these —
dead areas the margins of the individual spots usually remain distinct.
These spots should not be confused with those produced on apple
leaves by the apple-blotch Phyllosticta. The latter are yellowish and
minute, never more than one-sixteenth of an inch in diameter, and
will not be considered in this paper.
Leaf-spot is of greater economic importance than is generally sup-
posed. It makes its first appearance early in the spring as the leaves
are unfolding, and infections take place continuously throughout the
growing season. As a result of its attacks trees may become com-
pletely defoliated from six weeks to two months before the normal
period of leaf fall. If this is repeated for a series of years, the trees
become weakened and the life of the whole orchard is materially
shortened. Moreover, the fruit from such prematurely defoliated
32893—Bul. 121—_08—4 47
SS SS eS SS SS
SSS
=
eS SS
oe
48 MISCELLANEOUS PAPERS.
trees is small and of poor quality, and the fruit buds must necessarily
go into the dormant stage in a rather immature condition, often re-
sulting in a partial or complete failure of the next year’s crop.
CAUSE OF LEAF-SPOT.
Considerable confusion has existed as to the cause of this leaf-
spot disease. Though no inoculation experiments have been reported,
the disease has generally been conceded to be of fungous origin and
has commonly been attributed to Phyllosticta pirina Sacc., and less
commonly to Phyllosticta limitata Pk. and Sphaeropsis malorum Pk.,
while species of Hendersonia, Pestalozzia, and other fungi have been
reported as occurring on the diseased areas.
The disease in its economic aspect was first mentioned by Alwood ?4
in 1892, when he described a “ brown-spot ” of apple foliage and re-
ported a serious outbreak in the Virginia orchards during the preced-
ing summer. He attributed the trouble doubtfully to Phyllostecta
pirind.
In 1895 Kinney ? cited the same fungus as the cause of apple and
pear leaf-spots 1 in Rhode Island.
Stewart,® in 1896, reported a serious outbreak of leaf-spot on Long
Island caused by an undescribed fungus which Peck named Phyl-
losticta limitata.
In 1898 Alwood * again recorded the common occurrence of Phyl-
losticta pirina on leaf spots, but found Sphaeropsis malorum Pk. and
Hendersonia mali Thiim. associated with it.
Lamson,* in 1899, gave Phyllosticta pirina as the cause of * brown-
spot ” of apple folinge in New Hampshire, while Corbett,’ in 1900,
described a“ brown-spot,” or “ frog-eye,” in West Virginia due to . .
the same fungus.
In 1902 Stewart and Eustace’ questioned the parasitism of Phyl-
losticta pirina and P. “imitata. In their opinion “at least a large
part of the so-called apple leaf-spot is due to spray injury and weather
conditions and not to fungous origin.” They suggest that the fungi
in question live saprophytically on leaves injured by Bordeaux mix-
ture and arsenical sprays, or in the case of unsprayed trees on leaf-
spots which are in some way the result of atmospheric influences. A
possible explanation for the formation of the spots is “when a
shower is followed by bright sunshine, drops of water on the leaves
act as lenses and concentrate the sun’s rays to such an extent as to
overheat the tissues underneath.”
In 1902 Clinton® recorded Sphaeropsis malorum as the cause of
brownish spots on apple leaves in Illinois “ much like those of the
@'The serial numbers used in this paper refer to the bibliography, which will
be found on page 54.
121—-v
SSS Sh SS SS SE OS, ee EE Ee Ss
PLATE III.
Fic. 1.—APPLE LEAVES SHOWING LEAF-SPOTS PRODUCED BY NATURAL INFECTION.
Fic. 2.—APPLE LEAVES SHOWING LEAF-SPOTS PRODUCED BY INOCULATION WITH
SPHAEROPSIS MALORUM, PK.
Bul. 121, Bureau of Plant Industry, U. S. Dept. of Agricuiture.
ea ed
APPLE LEAF-SPOT CAUSED BY SPHAEROPSIS MALORUM. 49
leaf-spots or Phyllostictae fungi, but are apt to be more irregular
and larger.” The same author,? in 1903, stated that most of the apple
leaf-spot troubles in Connecticut were due to this same fungus.
Stone and Smith,’® 1903, in accounting for a serious outbreak
which occurred in Massachusetts the previous year say “ there can
be no reasonable doubt that frost was the destructive agency.” They
observed that the spotting of the leaves continued throughout the
summer, and that even as late as August spots as a result of spring
frost developed on leaves which had not previously shown the injury.
Sheldon,"! in 1907, transferred the fungus Phyllosticta pirina Sace.
to the genus Coniothyrium on account of the dark color of the spores
and proposed the name Coniothyrium pirima (Sace.) Sheldon. From
an examination of herbarium material and fresh specimens from dif-
ferent parts of the eastern United States there is no doubt that the
fungus commonly called Phyllosticta pirina in this country is a Coni-
othyrium. Apparently mature spores from a European specimen of
Phyllosticta pwina in the herbarium of the Department of Agricul-
ture are hyaline and ellipsoid, agreeing with the original description
of Saceardo,” so that his species may prove to be autonomous.
In view of the conflicting statements and apparent uncertainty as
to the cause of apple leaf-spot, the writers during the summer of
1906 and 1907 made a study of the disease in connection with demon-
stration spraying work in the Ozarks. It was found that Sphaerop-
sis malorum, contrary to the general belief, is the cause of the disease.
CULTURAL STUDIES.
A somewhat cursory examination of a large amount of leaf-spot
material collected in Arkansas during 1906 showed that there was no
one fungus which fruited constantly on the spots. The pycnidia of
Coniothyrium pirina (Sace.) Sheldon were found perhaps more
commonly than any other, but two species of Pestalozzia and one
each of Coryneum, Hendersonia, and Alternaria occurred frequently,
while occasionally the pycnidia of Sphaecropsis malorum and a spe-
cles of Septoria were met with. The same was true of specimens
received from Missouri, Nebraska, New York, Maryland, Virginia,
and West Virginia. Pure cultures of all of these fungi were easily
obtained by the poured-plate method. All grew well and fruited
abundantly on apple agar or sterilized apple wood. ,
In the early part of the season of 1907 cultures were obtained from
leaf spots by a somewhat different method. During the first spring
outbreak of the disease, spots of various sizes, together with a littie
of the surrounding healthy tissue, were cut from the leaf and placed
in a solution of mercuric chlorid (1-1,000) for two or three minutes.
The bits of leaf were then thoroughly washed in sterile water and
121—y
50 _ -MISCELLANEOUS PAPERS.
transferred to slanted apple or potato agar. The writers separately
made many sets of cultures by this method, using spots from leaves
of Ben Davis, Winesap, and White Pearmain trees. Within
a few days by the aid of a hand lens hyphe could be seen growing
out from the center or margins of the small spots. Mycelium devel-
oped rapidly and in about two weeks spores were formed, so that
the fungi could be identified. The results were uniformly the same.
In all cases in which the youngest spots, that is, those one-sixteenth
of an inch or less in diameter, were used, the fungous growth was a
pure culture of Sphaeropsis malorum Pk. In cultures made from
the older spots, in which the central tissue had become brown, some-
times a pure Sphaeropsis was obtained, but more often a mixture of
things. Coniothyrium pirina developed about as commonly as
Sphaeropsis, both species often growing from the same spot. In
addition to these two fungi, two species of Alternaria, a Cladospo-
rium, bacteria, and yeasts were frequently present.
This cultural work, frequently repeated, gave evidence that Sphae-
ropsis malorum, always developing from the youngest spots, was the
specific cause of the disease and that the other organisms were mere
concomitants. Of course, to prove this inoculation experiments were
necessary. These were made as soon as pure fruiting cultures of the
different fungi were obtained.
INOCULATION EXPERIMENTS.
A number of different sets of inoculations were made, but the
method of procedure was the same in each case. With a sterile
needle the fruiting fungus was scraped from the surface of the agar
and transferred to a tube of sterile water. In cases where pycnidia
were present these were crushed against the side of the tube with a
sterile glass rod to set free the spores. In order to ascertain the
presence of mature spores a hanging drop of the fluid was always
examined microscopically. This spore-bearing liquid was then
sprayed on both surfaces of clean young leaves with an atomizer.
Trees in more or less isolated young orchards were selected, and no
two fungi were used on the same tree. From 20 to 40 leaves on two
or three different shoots were involved in each inoculation. Checks
were always made on separate trees by spraying 40 or 50 leaves with
sterile water.
The first moculations were made on May 28, 1907. The fungi
used were Sphaeropsis malorum, and the undetermined species of
Coryneum, Hendersonia, and Alternaria previously mentioned. It
was raining at the time and the weather continued wet for several
days.
2A,
APPLE LEAF-SPOT CAUSED BY SPHAEROPSIS MALORUM. 51
On June 3, 1907, purple specks were appearing on the leaves which
had been inoculated with Sphaeropsis, and on June 18 these leaves
were badly affected with leaf-spot. (PI. III, fig. 2.) On a twig
bearing 30 leaves, 12 showed a dozen or more well-developed spots,
and a few of these leaves had from 80 to 90 spots each. ‘Twelve other
leaves on the same branch had from 2 to 10 spots each, while only
6 remained free from the disease. On another branch 12 out of 20
leaves were badly affected.
With the exception of an occasional spot, evidently resulting from
natural infection, the leaves sprayed with spores of the other fungi,
as well as those sprayed with sterile water as a check, remained free
from the disease.
Another experiment was made on June 19, 1907. Spores of Sphae-
ropsis malorum, Coniothyrium pirina, Coryneum, and Alternaria were
used. The work was done at sunset following a shower, so that the
leaves were wet. Again the leaves inoculated with the spores of
Sphaeropsis malorum soon became badly affected with the character-
istic leaf-spot disease, while the others, including the checks, devel-
oped no more than an occasional spot.
Another test was made with Sphaeropsis alone. The young leaves
of a 2-year-old tree were inoculated during a period of dry weather
in mid-June. The spores were sprayed on the leaves at about 10
o'clock, while the sun was shining brightly. At the same time
sterile water was sprayed on the leaves of an adjacent tree as a check.
Though no rain fell for at least six days after the spraying was
done, numerous purple specks began to appear on the inoculated
leaves within a week and soon developed into the characteristic brown
spots. A few spots, never more than one to a leaf, appeared on the
checks. The mature spores of Sphaeropsis germinate so rapidly that
in dry weather the dews: provide sufficient moisture for leaf infec-_
tion, as indicated by this experiment.
Inoculations made on June 26, 1907, with Sphaecropsis malorum,
Coryneum, and Alternaria gave results similar to those previously
recorded for these fungi. From 20 to 50 spots developed on each of
the leaves inoculated with Sphaeropsis, while only a few scattered
spots occurred on the leaves of the check and on those sprayed with:
spores of the other fungi.
On August 4, 1907, inoculations with Coniothyrium were again
tried. Leaves on rapidly growing 2-year-old Ben Davis trees in a
nursery were used. The spores were obtained from a fresh culture
and were so numerous that they clouded the liquid. The work was
done during a light shower and some rain fell the next day.
The same experiment was repeated on the evening of August 14,
1907. Though it did not rain at this time the trees were wet down
with sterile water on the following night. 3
121—v
LS
59 MISCELLANEOUS PAPERS.
Again, on August 21, 1907, this same fungus was used for inocula-
tions, which were made in the evening just after a heavy rain. For
the next two days the sky was overcast and occasional showers fell.
The results of these three sets of inoculations with Coniothyrium
were negative. Spots were found here and there on the inoculated
leaves, but no more than on the checks which were sprayed with
sterile water. Similar spots, never more than two to a leaf, were
found throughout the nursery at this time and were evidently pro-
duced by a natural infection with Sphaeropsis.
CONCLUSIONS.
The following conclusions may be drawn from the results of the
inoculation experiments described in the preceding pages:
Sphaeropsis malorum Pk., the black-rot fungus, is parasitic on
apple leaves, producing circular (or irregular) reddish brown spots
an eighth of an inch or more in diameter, and is undoubtedly the |
cause of the apple leaf-spot disease which occurs in the middle West.
The common apple leaf-spot disease of the Eastern States, being so
similar in every respect, is doubtless caused by the same fungus,
although some other fungi may possibly produce similar spots.
Coniothyrium pirina (Sace.) Sheldon, although it occurs abun-
dantly on apple leaf-spots, appears to have nothing to do with their
formation. 3
The several other fungi that were tested, such as Hendersonia sp.,
Coryneum sp., Pestalozzia sp., and Alternaria sp., proved to be non-
parasitic in these experiments and probably occur on leaf spots only
as saprophytes.
SOURCE OF INFECTION.
Sphaeropsis malorum is perhaps the most common fungus that
inhabits pome-fruit orchards east of the Rocky Mountains. It is the
cause of the black-rot of the apple, the pear, and the quince and pro-
duces cankers on trunks and branches of these fruit trees. It occurs
abundantly on dead twigs and branches in nearly every orchard, pro-
ducing spores in enormous numbers. This is perhaps the most fertile
source of infection for both fruit and foliage. In old orchards, par-
ticularly where pruning is neglected, the leaf-spot disease is much
worse than in young orchards. The leaves of young trees adjacent
to an old orchard become more spotted with the disease than those
farther removed. Another source of infection is the diseased fruits
of the previous year’s crop. Although the fungus fruits only spar-
ingly on leaves on the tree, it produces fertile pycnidia in consider-
able numbers on these leaves after they have fallen to the ground.
121—y
Ope pli OE,
Bul. 121, Bureau of Plant Industry, U. S. Dept. of Agriculture.
PLATE IV.
————— : ss —_—_—_—_—
a2
FiG. 1.—UNSPRAYED WINESAP TREES DEFOLIATED BY THE LEAF-SPOT DISEASE.
Fic. 2.—SPRAYED WINESAP TREES IN FULL FOLIAGE, LOCATED IN THE SAME
AND PHOTOGRAPHED AT THE SAME TIME (OCTOBER 19, 1906) AS THOSE SHOWN IN
FIGURE 1.
ORCHARD
APPLE LEAF-SPOT CAUSED BY SPHAEROPSIS’ MALORUM. 53
TREATMENT.
Since 1892, when Alwood ** first recommended Bordeaux mixture
as a preventive for apple leaf-spot, other writers have advocated the
same method of treatment. The prevention of this disease has been
one of the most striking results of various spraying experiments and
demonstrations conducted by the Bureau of Plant Industry. Waite,
in 1901, in connection with bitter-rot experiments in Virginia, con-
trolled the disease with two applications of Bordeaux mixture. His
recommendations in Farmers’ Bulletin No. 243, p. 19, are based upon
this work. Similar results were obtained by Scott ‘* in Virginia in
1905. In the spraying demonstrations in the Ozarks during 1906 and
1907 the writers found that the spraying ordinarily necessary for the
protection of the fruit from fungous attacks ¢ will usually control this
leaf trouble without any additional treatment. During both seasons
unsprayed trees were shedding their leaves by August 1 and were
completely defoliated by the middle of September, while the sprayed.
trees remained in full foliage until the first kilhng frost. (Compare
Pl. IV, figs. 1 and 2.) In addition to the injurious effect upon the
trees this premature defoliation caused the fruit to be small and of
poor quality as compared with that from sprayed trees. An average
barrel of Winesaps from sprayed trees contained 612 apples, while
731 from unsprayed trees in adjacent rows were required to fill a
barrel.
For the control of this disease alone, without reference to the
diseases of the fruit, an application of Bordeaux mixture should be
made in the spring a week or ten days after the petals have fallen, a
second application four weeks later, and a third about four weeks
after the second. Three applications are necessary only in exceed-
ingly wet seasons in sections where the disease is severe. Ordinarily
two treatments, one about three weeks after the petals are off and the
other four or five weeks later, are sufficient.
A weak Bordeaux mixture, such as 3 pounds of copper sulphate and
3 pounds of hme to 50 gallons of water, is effective in controlling this
disease, Bordeaux mixture of full strength not being required. ”
“For a combination ‘treatment for the leaf-spot disease, the diseases of the
fruit, and the codling moth, see Farmers’ Bulletin No. 283, pp. 41—42.
4 For yarious formulas and methods of preparing Bordeaux mixture, see
Farmers’ Bulletin No. 248, pp. 5-10.
121—v
BIBLIOGRAPHY.
*Alwood. Virginia Agricultural Experiment Station Bulletin 17, pp. 59, 62.
1892.
*Kinney. Rhode Island Agricultural Experiment Station Report 17 (1894),
pp. 188-189. 1895.
* Stewart. New York Agricultural Experiment Station Report 14 (1895), pp.
545-546. 1896.
*Alwood. American Association for the Advancement of Science, Proceed-
ings, vol. 47, p. 413. 1898.
’®> Lamson. New Hampshire Agricultural Experiment Station Bulletin 65, pp.
106-107. 1899.
*Corbett. West Virginia Agricultural Experiment Station Bulletin 66, pp.
202-204. 1900.
“Stewart and Eustace. New York Agricultural Experiment Station Bulletin
220, pp. 225-238: 1902. 7
‘Clinton. ITllinois Agricultural Experiment Station Bulletin 69, pp. 192-193.
1902.
°Clinton. Connecticut Agricultural Experiment Station Report, 1903, p. 298.
1903.
® Massachusetts (Hatch) Agricultural Experiment Station Report 15, pp.
32-34. 1908.
™ Sheldon. Torreya, vol. 7, pp. 142-143. July, 1907.
® Saccardo. Michelia, vol. 1, p. 134. 1878.
8 Alwood. Virginia Agricultural Experiment Station Bulletin 17, p. 64. 1892.
“Scott. Bureau of Plant Industry, United States Department of Agriculture,
Bulletin 93, p. 27. 1906.
121—yv
54
B. P. I.—347.
TEE TMMUNITY OF TE JAPANESE CHESINUT
TOUTE DARK DISEASE.
By Haven Mercar, Pathologist in Charge of the Laboratory of Forest Pathology.
THE EXTENT OF THE BARK DISEASE.
The bark disease of the chestnut, caused by the fungus Diaporthe -
parasitica Murrill, has spread rapidly from Long Island, where it was
first observed, and is now reported from Connecticut, Massachusetts,
Vermont, New York as far north as Poughkeepsie, New Jersey, Penn-
sylvania, and possibly Delaware. It is no exaggeration to say that it
is at present the most threatening forest-tree disease in America.
Unless something now unforeseen occurs to check its spread, the com-
plete destruction of the chestnut orchards and forests of the COULDA or
at least of the Atlantic States, is only a question of a few years’ time.
AN IMMUNE VARIETY.
Observations made by the writer during the past year indicate that
all varieties and species of the genus Castanea are subject to the
disease except the Japanese varieties (Castanea crenata Sieb. and
Zuce.). All of the latter that have been observed in the field or
tested by inoculations have been found immune. This fact can
hardly fail to be of fundamental importance to the future of chestnut
nut culture. Although the nuts are distinctly inferior in flavor to the
European varieties, such as Paragon, the Japanese chestnut is
already grown on a large scale as a nut-producing tree. There are,.
however, many trade varieties of dubious origin. Some. of these
may prove later to be subject to the disease. Immunity tests of all
known varieties of chestnuts have been undertaken.
Attempts will also be made to hybridize the Japanese with Ameri-
can and European varieties, with the hope of combining the or
of the former with the jesnetie qualities of the latter.
However excellent as a nut and ornamental tree, the value of ae
Japanese chestnut as a forest tree is doubtful. if ee be recom-
mended only experimentally at present for forest planting. It
_ 121—v1 dD
56 MISCELLANEOUS PAPERS.
certainly will not take the place of the American chestnut. The
tree is said to attain a height of 50 or 60 feet in Japan. As seen in
this country it is a handsome tree, dwarfish and compact in habit,
and rather slow growing. It has hardly had time to show how large
it can grow.
The immunity of the Japanese chestnut, together with the fact
that it was first introduced and cultivated on Long Island and in the
very locality from which the disease appears to have spread, suggests
the interesting hypothesis that the disease was introduced from
Japan. So far, however, no facts have been adduced to substantiate
this view.
121—VI
——,
tinntaiagt
INDEX.
Page.
Apple leaf-spot caused by Sphaeropsis malorum, paper..........-.-.--------- 47-54
Nesenic, absorption byigrowane: hopiplants.. 42.2225. 2es2 52.422) 2222 es eee 43-44
1 hopssimpure sulphur asa source, . 2255552 ae Se eae 44-45
sources in certain samples of dried hops, paper......2:.--..-.--+---:- 41-46
previous investigations... -.. 4]-42
Bark disease of chestnut, immunity of Japanese variety, paper.............-- 5d—-56
Beer yarse mie COMUCMI a atau elie Cakes nce teenie eg ays Ina Lees hae .... 41-46
Bordeaux mixture torapple:leat-spot. 23 255652. see Sse ol ee pe Sa 53
Cars meticctzol whiter smake;root mys Lee en eae eM ic aiereys Oud cvs ce memes eee 17-18
Chestnut tbankeehiseasememiemt.. 5. - se ial ae Le a Rup Sones ek ee 5d
Japanese, immunity to the bark disease, paper..........+.....------ 55-56
CRAWFORD, ALBERT CORNELIUS, paper entitled ‘‘Laboratory work on loco-
: weed investigations”....... 39-40
‘Mountain laurel, a poisonous
plant fe: ae cee tame 21-35
‘“The supposed relationship of
white snakeroot to milksick-
ness, or ‘trembles’’’........- 5-20
Disease, apple leaf-spot caused by Sphaeropsis malorum, paper.-.....-.-.-.--- 47-54
DALksOINCheSEMUtMeEXteliie ty Nas Ne ny Me eee Ee Son ode ey ges oe a 55
immunity of Japanese variety, paper.............-. . 50-56
Dogs eect Ol winlte, SMa KeKOOt sae Sees a ey me lt dees Gace Body a 18
Eupatorium ageratoides, relationship to milksickness, or ‘‘trembles,’’ paper .. 5-20
Fruit disease, apple leaf-spot caused by Sphaeropsis malorum, paper.........- 47-54
Fungus causing bark disease of chestnut, immunity of Japanese variety, paper.. 55-56
Sphaeropsis malorum, cause of apple leaf-spot, paper............----.- 47-54.
Flops, absorption of arsenic by growing plants: 3-222. 4.2229.0.0.2...2--25).. 22. 43-44
dried, sources of arsenic in certain samples, paper...:..............--- 41-46
summary of results of recent
investigations). .........: 45-46
Prewious imvestigations: 22/2 UI . 41-42
examined to determine arsenic content, origin .........-------.-.--.-- 42-43
soils examined to determine whether arsenic was present......-.---.--- 43
Immunity of the Japanese chestnut to the bark disease, paper........---- 1... 55-56
Inoculation! experiments), apple leal-spot_2. 025.) -. 00400205 22.024. 22 2 ee. 50-52
Japanese chestnut. See Chestnut, Japanese.
Kaba latiolha.anpoisonousplant.papen.. 2. 090.02 Soe... 21-35
Laboratory work on loco-weed: investigations, paper.........---- AE A a) ae 39-30
Eeurel, mountamms, a;poisonous plant, papers). 0 le ke ee ee 21-35
ACHVEROMMCIDIC OMpOISGMe eee hee ee ok ee 30-34
eliectronbiralblsiise sequen ee ey LY Le et eae 29-30
1 ah(syeyoy Ae aes es ee ee ein Sea OES 26-29
121 57
58 MISCELLANEOUS PAPERS.
Page. _.
Laurel, mountain, general symptoms-of poisoning]_-__ 2-1-2... 2.222) 2s ee 30
history-and poisonous qualitiestegy==ss 2) = See 21-96
medicinal action. 4/2526 2. ae ee ee eee 34-35
poisoning, remedial agents............. ee oe Re 2. eee ee 34°
Leaf-spot of apple, bibliography ......... Pees) oe = trae che he es 54
CAUSE S:s Lye Seles DSS AS ee ra en Se ec Re ee ee 48-49
caused by Sphaeropsis malorum, papern.94 22 222.422 47-54
Characteristics .5472 oy: ec 5 Se eee pS Lee cre neh eres 47-48
culturalistudiesizes) 2,5 2) eee erica zu ie See eee 49-50
inoculationvex periments. ee ee eee a ones eres 50-52
summary of results of investiga-
GlONS Agee aa: OSE a Se eee 52-63
SOUrCe OL INTEC HOM. f= hk Hae ge Ren ieee te ose are ee ae 52
TReatment wees hy Bee Bake SRD a Te eclectic te Seen 53
Woco=weed investigationsan the telds papers. 25) eee eee 37-38
laboratory work, paper......-.--.-- ae eet 39-40
Man settect ol, wintte: Smalceroo bs cee ce ere eee ee 19
Marsu, ©. Dwicut, paper entitled ‘“‘ Results of loco-weed investigations in the
HOLY cies saiatie ene Sc Sethe eee ae ee a 37-38
Metcatr, Haven, paper entitled “‘The immunity of the Japanese chestnut to
the bark disease!? 3 5.1222 Sao Sse A es re ee ee re 55-56
Milksickness, or ‘“‘trembles,’’ history of disorder and previous experiments .... 5-15
recent IMVesiieanlOnse:.) ase es eee Pera Sea 15-19 .
SUMMA TYR Sere oem ee ae 19-20
supposed relationship of white snakeroot, paper.. 5-20
Moseley, EH. L., experiments wath white snakeroot. 22 22505-22222. 2.55225 aes 12-15
Mountain laurel. See Laurel, mountain.
INutstrees: chestnut: cbark«diseasesit ee Ste ee 55-56
Orchards, apple, infected with leaf-spot caused by Sphaeropsis malorum, paper. 47-54
Roison, mountain laurel, active principles. (225) =) ees ee nee eee 30-34
Poisoning by mountain laurels eeneralisymptoms >: 2 55562 55 2c ese es 30
remedialiagents::. 23. See a eee eee 34
Poisonous plant, loco weed, investigations, papers.......-...----------------- 37-40
mountaimplaurel ;pa pers Les. sags et ees ae ee 21-35
white snakero0b, papercaase 4) s28 ty a es eines eee 5-20
Rabbits, effect of extracts from ash of white snakeroot........-..--.---.------ 17
of dry plants of white snakeroot...........---.:..-- 15-16
fresh plants of white snakeroot preserved in chloro-
PORTS 2S 88 .c een eee wie ie a ycis area et ma enemegs 16-17
mountain Warned: << 5 eee os RE ees ke ek ees ee 29-30
Relationship of white snakeroot to milksickness, or “‘trembles,’’ paper.......- 5-20
Results of loco-weed investigations in the field, paper............------------- 39-40
Rorer, JAMES Brreu, and Scorr, Wmi11AmM Moors, paper entitled ‘‘ Apple leaf-
Spot caused by Sphaeropsis;malonum 2255242222 4-85 See 4. eee eee eer 47-54
Scorr, Wm11AmM Moors, and Rorer, JAMES Brrcu, paper entitled ‘‘ Apple lea#-
spot caused by Sphaeropsis malorum 7. 222 s2228. 32 e = ee 47-54
Sheep; effect of mountain laurel. <2 22 2 eee oe te en 26-29
white shakeroot. io. ies (ck Se eae ee 19
Snakeroot, white, effect on catse 2. 2o. cs es ORE eek ee ee ee ee 17-18
dogs.iu. 2. 2532 SEES ER ee ei eee ee 18
MAM es SS ek Oe Re ee ee ree eee 19
rabbits ey ct ho oe ce Sees. eee eee 15-17
Sheep. .22- oice cae oe tes = eet Se 19
supposed relationship to milksickness, or ‘‘trembles,’? paper. 5-20
121
INDEX. 3 59
Page
Sources of arsenic in certain samples of dried hops, paper..........-.--------- 41-46
Sphaeropsis malorum, cause of apple leaf-spot, paper.....-.....------------ 47-54
Stockspoisonine with loco-weed!, papers 0-1. yawn aimee cera! ee 8 kde, Lots ee) 37-40
mountain: laurels. pa pers scm samt re ei cian Ame 21-35
Winter sma Kero ten see ee en enone ce ned ear ey 8-11, 19
STOCKBERGER, WARNER W., paper entitled ‘‘The sources of arsenic in certain
Sales Olmdime de MOPSie taka se. shea 3 ste Nee Ee cue rien eam Segment a a 41-46
SulphiinEyumpure.as)2 source: of arsenic im hopsesece. ess sc ose ee as 44-45
Supposed relationship of white snakeroot to milksickness, or ‘‘trembles,’’? paper. 5-20
“Trees, apple, infection by Sphaeropsis malorum, paper.......--....--------+- 47-54
chestnut, bark disease, immunity of Japanese variety, paper.....-..---- 55-56
‘“Trembles,”’ or milksickness, supposed relationship of white snakeroot, paper. 5-20
121
O