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July 1828. 



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THE 

PHILOSOPHICAL MAGAZINE 

AND 

ANNALS OF PHILOSOPHY: 

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NEW SERIES. 

No 19.— JULY 1828. 



B.Y 

RICHARD TAYLOR, F.S.A. F.L.S. M. Astr. S. &c. 

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The Drawings of the Spots on the Sun will be acceptable. 

We are authorized to announce the intention of Dr. Prout to reply 
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TABLE OF CONTENTS. 



NUMBER XIX.— JULY. p 

Mr. Haidinger on Herderite, a new Mineral Species 1 

Reply of Drs. Tiedemann and Gmelin to the Remarks of Dr. 
Prout inserted in the Annals of Philosophy (Second Series), 

vol. xii. p. 405 : Communicated by Dr. T. Thomson 3 

Mr. Ivory on the Latitudes and Difference of Longitude of 
Beachy Head and Dunnose in the Isle of Wight, as laid 
down in the Trigonometrical Survey of England ; and the 
Length of a Degree perpendicular to the Meridian at the 

Latitude of Beachy Head 6 

Mr. Walker's Additional Remarks on the Artificial Production 

of Cold 11 

Observations on the Geology of the Hyderabad Country .... 12 

Mr. Sharpe on the Figure of the Cells of the Honeycomb 19 

Dr.Turner's Chemical Examination of the Oxides of Manganese 

{continued) 22 

Dr. Green's Experiments on the Pressure of the Sea, at consi- 
derable Depths . . 36 

New Books : — Mr. Martin's Geological Memoir on a Part of 

Western Sussex ; — Fife's Elements of Chemistry 38 — 55 

Proceedings of the Royal Society 55 

•' Linnaean Society 61 

1 1 ■ Astronomical Society 62 

at the Friday Evening Meetings of the Royal 

Institution of Great Britain 64? 

Direct Method of ascertaining the Velocity of Cannon-Balls. . 65 
Chrysolite in the Cavities of Obsidian — Meteor of a Green 

Colour — Bitter of Aloes : Carbazotic Acid 66 

Heat developed during Combustion — On the Sugar of Liquo- 
rice Root 67 

Solution in Sulphuric Acid without Oxidizement 68 

Vegetable Albumen and Gelatine 69 

Anhydrous Crystals of Sulphate of Soda— Caseous Oxide, and 

Caseic Acid 71 

Rib of a Whale found in the Diluvium of Brighton Cliffs 72 

Inequality of the Dark Space between the Body of Saturn and 

its Ring — Native Iron ? slightly arseniuretted 73 

Arseniate of Cobalt 75 

Solar Spots, &c. — New Patents 76 

Meteorological Observations 78 

made at the Garden of the Horti- 
cultural Society at Chiswick, near London, by Mr. Giddy at 
Penzance, Dr. Burney at Gosport, and Mr. Veall at Boston 80 



NUMBER XX.— AUGUST. 

M. A. Brongniart on Websterite found in the Plastic Clay of 
Auteuil, near Paris . , , , , . , 81 

Sir 



IV CONTENTS. 

Page 

Sir H. Davy on the Phaenomena of Volcanoes 85 

Dr. Hare'sRationale of the Difficulty of separating Plane Sur- 
faces by a Blast, in certain Cases 94? 

Dr.Turner's Chemical Examination of the Oxides of Manganese 96 

Prof. Gauss's General Solution of the Problem : to represent 

the Parts of a given Surface on another given Surface, so 

that the smallest Parts of the Representation shall be similar 

to the corresponding Parts of the Surface represented (con- 

tinned) 104* 

Prof. Del Rio's Analysis of two new Mineral Substances, con- 
sisting of Bi-seleniuret of Zinc and Sulphuret of Mercury, 

found at Culebras in Mexico 113 

Mr. Pentland's Observations on the Peruvian Andes, in reply 
to a Paper by M. Coquebert de Montbret, in the Annates 

des Scie)ices Naturelles 115 

Mr. J. de C. Sowerby on the Penetration of Water into stop- 
pered and corked Bottles sunk to a great Depth in the Sea 119 
Dr. Prout's further Remarks on Messrs. Tiedemann and 

Gmelin's Observations on the Acids of the Stomach 120 

Mr. Sharpe on the vitrified Fort of Dunnochgoil, in the Isle of 

Bute 123 

Mr. Seers's Method of solving adfected Quadratic Equations 125 
Dr. Hare's Improved Eudiometrical Apparatus (continued) . . 126 
New Books : — Rev. Dr. Pearson's Appendix to the First Volume 
of An Introduction to Practical Astronomy ; — Dr. Harwood 
on the Curative Influence of the Southern Coast of England 134? 

Proceedings of the Astronomical Society 136 

' Royal Academy of Sciences of Paris. ... 139 

New Astronomical Ephemeris • 14?1 

Mr. Dunn's Improved Air-Pump 145 

Gallates of Quina and Cinchonia — Preparation and Properties 

of Aluminum 147 

Chloride and other Compounds of Aluminum 149 

Native Iodide of Mercury — Corydalin, a new Vegetable 

Alkali 151 

Action of Alkalies and their Carbonates, &c. on Iodides — Citric 

Acid from Gooseberries 152 

Solanine — Blue Colour by the Action of Muriatic Acid upon 
Albumen — Botryogene, or Native red Iron-vitriol of Fahlun 153 

Erinite, a new Mineral Species 154? 

Alteration of Crystalline State in Solids—Decomposition of 

Ammonia by Metals — Iodides of Carbon 155 

Solar Spots 156 

New Patents— Mr. Herapath 157 

Meteorological Observations * 158 

made at the Garden of the Hor- 
ticultural Society at Chiswick, near London, by Mr. Giddy 
at Penzance, Dr. Burney at Gosport, and Mr. Veall at Boston 160 

NUMBER 



CONTENTS. V 

Page 

NUMBER XXL— SEPTEMBER. 

Mr. Rob. Brown's brief Account of Microscopical Observations 
made in the Months of June, July, and August, 1827, on 
the Particles contained in the Pollen of Plants ; and on the 
general Existence of active Molecules in Organic and Inor- 
ganic Bodies 161 

M. Steinheil on a New Micrometer, principally intended for 

the Construction of a more complete Map of the Heavens 173 
Mr. Galbraith's Comparison of a Formula representing the 
Velocity of Sound, with Capt. Parry and Lieut. Foster's Ex- 
periments on that Subject at Port Bowen ; with some Re. 

marks on the Ellipticity of the Earth 179 

J.L.T. on the Reduction of CircummeridianAltitudes of the Sun 182 

Dr. Hare's Improved Eudiometrical Apparatus 183 

Dr. Hare on the Litrameter 187 

Mr. Ivory on Measurements on the Earth's Surface perpendi- 
cular to the Meridian 189 

Mr. De la Beche on the Tables of Oltmanns for calculating 
Heights by the Barometer, rendered applicable to English 

Barometers and Measures • • • 194? 

Prof. Gauss's General Solution of the Problem: to represent 

the Parts of a given Surface on another given Surface, so 

that the smallest Parts of the Representation shall be similar 

to the corresponding Parts of the Surface represented .... 206 

Mr. Graham on the Influence of the Air in determining the 

Crystallization of Saline Solutions 215 

Mr. Nixon's Method of avoiding certain sources of inaccuracy 

in the use of Kater's Horizontal Floating Collimator 218 

Mr. Gray's Description of a new Kind of Pear-Encrinite found 

in England 219 

New Books : — Watkins'sPopularSketch of Electro-Magnetism, 

or Electro-Dynamics 220 

Proceedings of the Geological Society 222 

. Medico-Botanical Society 227 

Tubes formed by Lightning— Artificial Ultramarine 228 

Mellitic Acid 229 

M. Fischer on the Action of Acids on Palladium 230 

M. Brandes's Preparation of Conia, the Alkali of the Conium 

Maculatum — On Pyrophorus 23 1 

Effect of Ebullition upon Cupreous Salts 232 

Boruret of Iron— Varieties of Borax — Figure of the Cells of 

the Honeycomb 233 

Mr. Buchan's Experiments on the Amalgamation of Silver- 
Ores — Mr. Otley's Account of a cheap and easily-construct- 
ed Barometer for measuring Altitudes, &c 234 

Nummulites in the Green-sand Formation 235 

Fossil Herbivorous Reptiles — Solar Spots 236 

New Patents 237 

Meteorological Observations , 238 

Meteoro- 



VI CONTENTS. 

Page 

Meteorological Observations made at the Garden of the Horti- 
cultural Society, at Chiswick, near London, by Mr. Giddy 
at Penzance, Dr.Burney atGosport, and Mr. Veall at Boston 240 



NUMBER XXII.— OCTOBER. 

Mr. Ivory on the Method employed in the Trigonometrical Sur- 
vey for finding the Length of a Degree perpendicular to the 

Meridian 241 

Mr. Ivory's Remarks on an Article in the Bulletin des Sciences 

Mathematiques Physiques et Chimiques for March 1 828 .... 245 
Prof. Encke on the Construction and Arrangement of the New 

Berlin Astronomical Ephemeris 248 

Mr. Meikle on an improved Syphon-Hydrometer 258 

Mr. Haworth's New Account of the Genus Eclieveria 261 

Mr. Graham's Account of the Formation of Alcoates, Definite 
Compounds of Salts and Alcohol analogous to the Hy- 
drates (continued) 265 

Mr. Addison's Remarks on the Influence of Terrestrial Radia- 
tion in determining the Site of Malaria (continued) 272 

Mr. Children's Abstract of the Characters of Ochsenheimer's 
Genera of the Lepidoptera of Europe ; with a List of the 
Species of each Genus, and Reference to one or more of their 

respective Icones (continued) 278 

Mr. R. Phillips on the Crystalline Forms and Composition of 

the Sulphates of Nickel 287 

Mr. George's Chemical Examination of some of the Substances 

connected with an Egyptian Mummy 290 

Proceedings of the Geological Society 294 

Astronomical Society 298 

Royal Academy of Sciences of Paris .... 301 

Chlorine in Black Oxide of Manganese 306 

Brown Oxide of Chromium 307 

Masses of Native Platina —Preparation of Titanic Acid 308 

M. F. Wohler's Artificial Formation of Urea 309 

Native Iron in the United States 310 

Fossil Reptiles — Method of Preserving Funguses 312 

Difference of Longitude between Paris and Greenwich — Figure 

of the Cells of the Honeycomb 313 

M. Fayolle on Varignon's Method of solving Equations of the 

Second Degree — Mineralogical Literature 314 

Scientific Books 315 

New Patents — Meteor 316 

Aurora Borealis ? — Solar Spots 317 

Meteorological Observations 318 

made at the Garden of the Hor- 
ticultural Society at Chiswick, near London, by Mr. Giddy 
at Penzance, Dr. Burney atGosport, and Mr. Veall at Boston 320 



NUMBER 



CONTENTS. yii 

NUMBER XXIII.— NOVEMBER. 

Page 

Mr. Ivory's Answer to an Article by Mr. Henry Meikle, pub- 
lished in No. VII. of the Quarterly Journal of Science 321 

Mr. Addison's Remarks on the Influence of Terrestrial Radia- 
tion in determining the Site of Malaria 326 

Mr. Graham's Account of the Formation of Aleoates, Definite 
Compounds of Salts and Alcohol analogous to the Hydrates 331 

Capt. Kater on the Luminous Zone observed in the Heavens 
on the 29th of September last 337 

Expression for the Time of Vibration of a simple Pendulum in 
a Circular Arc 338 

A Letter to William Morgan, Esq. F.R.S. on the Experience 
of the Equitable Society 339 

Mr. Children's Abstract of the Characters of Ochsenheimer's 
Genera of the Lepidoptera of Europe ; &c. [continued) .... 343 

Capt. Cullen's Notice of the Geological Features of a Route 
from Madras to Bellary, in April and May 1822 (continued) 355 

Prof. Airy in reply to Mr. Galbraith's Remarks on some late 
Computations of the Earth's Ellipticity 364? 

Dr. Tiarks on Mr. Dalby's Method of finding the Difference of 
Longitude between two Points of a Geodetical Line on a 
Spheroid, from the Latitude of those Points and the Azi- 
muths of the Geodetical Line at the same 364 

New Books: — Wallace's Elements of Algebra; — Lea's De- 
scription of Six New Species of the Genus Unio 370 — 372 

Proceedings of the Royal Geological Society of Cornwall. . . . 374 

Royal Academy of Sciences of Paris. . . . 377 

Commemoration of the Second Centenary of the Birth.day of 
John Ray 379 

Agency of Carbonic Acid in decomposing Water by the Con- 
tact of Iron 381 

Conducting Power of Metals for Electricity 382 

Conducting Power of different Fluids for Voltaic Electricity — 
Hypophosphorous Acid and Hypophosphites 383 

Collecting Air for Analysis — Chloride of Sodium and Silver — 
M. Berzelius's Observations on Amber, h 384 

Influence of Magnetism upon Chemical Action — Influence of 
Gum-Arabic in the Precipitation of Lead by Sulphates — 
Combination of Chlorine with Prussiate of Potash 385 

Preparation of PureMalate of Lead — Mr. Trevelyan's Descrip- 
tion of the Winch Bridge, the oldest Suspension Bridge in 
England 386 

Chlorophseite discovered in Northumberland — Novaculite. . . . 387 

Chelmsford Philosophical Institution 388 

Dr. Forster on the Zodiacal Light of the 29th of September, as 
it appeared from Chelmsford 389 

Solar Spots 390 

The Planet Venus— Aurora Borealis 592 

Aurora Borealis? 393 

Mr. 



Vlll CONTENTS. 

Tage 
Mr. George Innes on Certain Errata in Dr. Mackay's Tables 

of Versed Sines 394 

Obituary :— Mr. John Atkinson, F.L.S. &c 395 

New Patents 396 

Meteorological Observations 397 

.. made at the Garden of the Horti- 
cultural Society at Chiswick, near London, by Mr. Giddy at 
Penzance, Dr. Burney at Gosport, and Mr. Veall, at Boston 399 
Calendar showing the Times of Meeting of the Scientific Bodies 
of London for 1828—9 400 

NUMBER XXIV.- DECEMBER. 

Mr. J. Phillips's Geological Observations made in the Neigh- 
bourhood of Ferrybridge, in the Years 1 826-1828 401 

Prof. Encke on the Calculations requisite for predicting Oc- 

cultations of Stars by the Moon 409 

Mr. Dalton on the Height of the Aurora Borealis above the 
Surface of the Earth ; particularly one seen on the 29th of 

March, 1826 418 

Mr. Dakin on the fitting-up of Microscopes for the Examina- 
tion of Opaque Objects requiring high Powers ; &c 429 

Mr. Ivory on the Method in the Trigonometrical Survey for 
finding the Difference of Longitude of two Stations very lit- 
tle different in Latitude 432 

Capt. Cullen's Notice of the Geological Features of a Route 

from Madras to Bellary, in April and May 1822 435 

Mr. Sharpe on the Figure of the Earth 343 

Mr. Children's Abstract of the Characters of Ochsenheimer's 

Genera of the Lepidoptera of Europe ; &c. (continued.) . . . . 444 
Attack of Berzelius on Dr. Thomson's " Attempt to establish 

the First Principles of Chemistry by Experiment" 450 

On the Luminous Belt of September the 29th . . 453 

Proceedings of the Linnaean Society 454 

Royal Academy of Sciences of Paris. . . . 455 

Meteoric Iron in France 457 

Iron Trade — Early History of Electro-Magnetism — Russian 

Coinage of Platina „ 458 

Analyses of Minerals — M. Vauquelin's Analysis of the Ipeca- 
cuanha Branea 459 

Plan for investigating the Natural Productions of Jamaica. . . . 460 
M. Fayolle on a Method by La Place of solving Equations 

of the Third Degree 462 

Luminous Belt of September 29th 463 

Encke's Comet 464 

Meteorological Observations 465 

made by Mr. Booth at the Garden 

of the Horticultural Society at Chiswick, near London ; by 
Mr. Giddy at Penzance, Dr. Burney at Gosport, and Mr. Veall 

at Boston 467 

Index 468 



THE 



PHILOSOPHICAL MAGAZINE 



AND 



ANNALS OF PHILOSOPHY, 



[NEW SERIES.] 



JULY 1828. 



I. On Herderite, a new Mineral Species. By W. Hai dinger, 
Esq. F.R.S.E.* 

1. General Description. 

FUNDAMENTAL form, a scalene four-sided pyramid, 
P=141° 16', 77° 20', 116° 3'. (Fig. 1.) Ratio of the axes 
a : b : c = 1 : s/2'55 : */0-46. 

Simple forms. (P-2) 4 (o) = ,149° 50', ; 

($P-2) 3 (rc) = ,134° 35', ;P(F); (Pr+oo) 5 (0 = 

115° 7'; (P+ oo ) 6 (5) = 42° 58'; Pr (M) = 115° 53'; Pr+ 00 
(r); Pr+ 00 (P). 

Combinations observed. 1. P r •P'(Pr+co) 5 .Pr+oo. 
(Fig. 2.) 





_2.Pr.{P-2)\($P-2)*.'P.(Pr + oo ) 5 . (P+ 00 ) 6 .Pr+ co. 
Pr+ 00. 

* Communicated by the Author. 

New Series. Vol. 4. No. 19. July 1828. B Cleavage, 



2 Mr. Haidinger on a new Mineral Species (Herderite). 

Cleavage distinct, parallel to the faces M, r but interrupted ; 
also perpendicular to the axis, the latter only in detached por- 
tions of very bright and even faces, and faint indications pa- 
rallel to P. Fracture small conchoidal. 

Surface, M very smooth, and delicately streaked parallel 
to its edges of combination with P, and resembling in this re- 
spect all the faces of the pyramids, n, o, and p, situated be- 
tween them. 

The faces r and s are very narrow, and somewhat curved. 
Those marked t and P, have a peculiar granulated aspect, but 
they are at the same time pretty smooth, particularly the latter. 

Lustre, vitreous, slightly inclining to resinous. Colour se- 
veral shades of yellowish- and greenish-white ; streak white, 
strongly translucent. 

Very brittle. Hardness = 5*0, equal to that of apatite. 
Specific gravity =2*985. 

2. Observations. 

1. I observed and examined the characters of this species 
in the summer of 1823, but deferred publishing the description 
of it, with a view of collecting further observations on other 
varieties of the same species, an expectation which was not 
realized. The only specimen of herderite, at present known, 
is in the Wernerian Museum at Freiberg. It was pointed 
out to me by M. Von Weissenbach, then Keeper of the mu- 
seum, as containing crystals, whose forms he could not exactly 
refer to those of apatite, among the varieties of which it was 
exhibited. The different aspect of the faces p and t, the 
former being smooth or but faintly streaked parallel to their 
intersections with P, while the latter are granulated, showed 
that the forms did not belong to the rhombohedral but to the 
prismatic system ; and I did not hesitate in pronouncing the 
mineral to be a new species, which I requested permission to 
examine more minutely. This permission was very liberally 
conceded. Mr. Breithaupt, who was then present, and had 
himself at a former period placed the specimen in the cabinet 
of Werner, likewise concurred in acknowledging the species 
to be a new one. 

Through the kind intercession of Mr. Reich, now keeper 
of the museum, I was favoured, during my stay at Berlin in 
the winter of 1825, with some fragments of the specimen for 
analysis, by Baron Von Herder, the present Ober-Berghaupt- 
mann, or director of every thing connected with mining pro- 
ceedings in Saxony. It is in compliment to that nobleman, 
that I propose the name of Herderite for the species ; and I 
feel particularly gratified in thus expressing to one of my 

earliest 



Drs. Tiedemann and Gmelin in reply to Dr. Prout. 3 

earliest mineralogical friends, the acknowledgement of the 
many instances of his having communicated to me rare speci- 
mens for examination, particularly during my stay at Freiberg. 
2. Herderite occurs imbedded in fluor, in the tin mines 
of Ehrenfriedersdorf; in Saxony. It resembles apatite, with 
which it was formerly confounded, in a remarkable degree ; 
particularly some of those named asparagus-stone : such as the 
variety from Zillerthal, in Salzburg, and that from Hof in 
Gastein in the same country, which is found accompanying 
the axotomous iron-ore of Mohs, and still more so certain 
pale greenish- white masses of the same species, which occur, 
though in small quantity, along with the zoisite from the 
Saualpe in Carinthia. The resemblance among those species 
is sufficient to class the herderite in the genus Fluor-haloide of 
Mohs, in which it may be henceforth included as the "pris- 
mati Fluor-haloide" 

II. Reply of Drs. Tiedemann and Gmelin to the Remarks of 

Dr. Prout inserted in the Annals of Philosophy (Second Series), 

vol. xii. p. 405 : Communicated by Thomas Thomson, M.D. 

F.R.S. fyc. Regius Professor of Chemistry in the University 

of Glasgow. 
r T > HE more satisfied we are of the obligations which the 
* doctrine of digestion lies under to Dr. Prout, and the less 
intention we had to attack him unjustly, the more do we con- 
sider it as our duty to discuss the complaints which he has 
made, so far as we are concerned, — to defend ourselves, where 
we think ourselves in the right, and to acknowledge our mis- 
takes where we think ourselves in the wrong. 

Dr. Prout's complaints are the following : 

1 . We have led our readers to believe that Dr. Prout denies 
the presence of every other free acid in the contents of the sto- 
mach, except the muriatic; which is not the case. 

Yet we could draw no other conclusion from Prout's paper*, 
than that he denied the presence of every other acid. For 

a. He says (page 118), " the experiments above mentioned 
seemed to preclude the possibility of the presence of any de- 
structible acid ; and the only known fixed acids likely to be 
present were the sulphuric and phosphoric; the muriate of 
barytes, however, neither alone nor with the addition of am- 
monia, produced any immediate precipitate, showing the ab- 
sence of these two acids in any sensible quantity, and still 
further confirming the results as before obtained." 

b. Now unless the absence of other free acids be taken for 

* Phillips's Annals of Philosophy, vol. viii. p. 117. 

B 2 granted, 



4 Drs. Tiedemann and Gmelin in reply to Dr. Prout 

granted, how can Prout's method of determining the free mu- 
riatic acid in the contents of the stomach be considered as an- 
swering the object in view ? When free acetic acid, for exam- 
ple, is present, the potash employed to saturate the free acid 
will not only saturate the free muriatic acid, but also the free 
acetic acid. Now as Prout considers his method as quite ac- 
curate, he must necessarily presuppose the absence of all other 
free acids. Indeed Dr. Prout would have had reason to com- 
plain of us, if we had led our readers to believe that he ad- 
mitted the presence of any other free acid in the liquid of the 
stomach ; — acetic acid, for example (which is not the case in the 
paper to which we have alluded). For on such a supposition his 
method would be no longer accurate ; and we should therefore 
have placed him in the situation of contradicting himself. 

Dr. Prout, in his remarks upon our treatise, has for the first 
time, so far as we know, admitted that he has several times 
found acetic acid along with muriatic acid in the liquid of the 
stomach. Thus our observations have been confirmed ; and 
it follows as a consequence, that his method of determining the 
quantity of free muriatic acid in the stomach cannot be relied 
upon. That the free acetic acid always proceeds from the food, 
we cannot believe ; as we have frequently obtained it by the di- 
stillation of the liquid in the stomach of animals which had 
long fasted, and whose gizzards had been stimulated by the 
swallowing of stones, &c. 

2. We have in our account of Proufs method passed by the 
most important point of the whole, because it constituted a check 
upon the rest of the procedure. 

Undoubtedly the determination of the muriatic acid in the 
sublimed sal ammoniac, obtained after the saturation of the 
liquid of the stomach with potash, is very important ; and it 
constitutes a still more important check, when one denies (as 
Prout evidently did in his first paper) the presence of any 
other free acid in the liquid of the stomach. But as we had 
discovered the presence of several volatile acids, particularly, 
of acetic acid, we could not estimate this check as of the least 
value. For when the liquid of the stomach, together with mu- 
riate of soda (and potash), contains muriate of ammonia and 
free muriatic and acetic acids, and we neutralize it exactly 
with potash, evaporate it to dryness and sublime, the acetate 
of potash and sal ammoniac which it contains mutually de- 
compose each other, and are converted into chloride of po- 
tassium and acetate of ammonia. So that in consequence of 
the presence of acetic acid, less sal ammoniac will sublime than 
the liquid of the stomach originally contained. Indeed none 
at all will sublime, if the quantity of acetic acid be sufficiently 

great. 



on the Presence of free Acids in the Stomach. 5 

great. It is probably owing to this cause that Prout found 
no sal ammoniac in the liquid from the human stomach in two 
cases ; although the complete absence of this salt from such 
liquids is very unlikely*. From these observations it seems 
probable that the proof of the presence of free muriatic acid, — 
which Prout has lately endeavoured to deduce from the cir- 
cumstance, that when the liquid of the stomach after having 
been neutralized with potash was evaporated to dryness, and 
the residue exposed to a red heat, this residue did not act 
as an alkali but constituted a neutral salt, — is not satisfactory. 
For a liquid of the stomach which contains no free muriatic 
acid, but muriate of soda, muriate of ammonia, and free acetic 
acid, must (if the quantity of acetic acid be not too great) after 
neutralization with potash and ignition contain only chloride 
of potassium and chloride of sodium. 

We are of opinion that Dr. Prout himself in his last state- 
ment has admitted that when an organic acid is present, his 
process is insufficient, and has thus confirmed our own pre- 
vious statements. 

3. We have misrepresented Prout & opinion respecting the ap- 
pearance of albumen in the intestines, by making him maintain 
that no albumen exists in the liquid of the stomach even when 
the animal takes food containing albumen; but that it shows it- 
self first in the duodenum, in consequence of the union of the li- 
quid of the stomach with the bile and the pancreatic juice. 

After again perusing Prout's former paper f , we must ac- 
knowledge that we have stated his opinion on this subject quite 
inaccurately. Whether this proceeded from misunderstanding 
his meaning, or from an inaccurate extract from his paper, we 
cannot say. We request the reader of our work to obliterate 
the passage which refers to this misunderstanding on our part. 

We trust that these explanations and acknowledgements 
will obviate the complaints of this celebrated chemist and phy- 
sician, to whom the chemical part of physiology and pathology 
lies under so many obligations. We have only to express 
our high satisfaction at his statement, that his observations on 
digestion agree with ours, and confirm them in the most im- 
portant points. 

* It is true, Prout determined the quantity of sal ammoniac by another 
method. From the total quantity of muriatic acid contained in the liquid, 
he subtracted the portion united to a fixed alkali, and that which existed 
in a free state. The remainder must represent the portion combined with 
ammonia. But as the presence of acetic acid would lead him to overrate 
the quantity of free muriatic acid, the sal ammoniac as thus estimated would 
be too little or none at all. 

t Annals of Philosophy (first series), vol. xiii. p. 12. 

III. On 



I « ] 

III. On the Latitudes and Difference of Longitude of Bcacky 
Head and Dunnose in the Isle of PVight, as laid down in the 
Trigonometrical Survey of England; and the Length of a 
Degree perpendicular to the Meridian at the Latitude of 
Beachy Head. By J. Ivory, Esq. M.A. F.RS* 

r I ^HE investigation of the figure of the earth by measure- 
■*- ments of the meridian, has given rise to a question of great 
moment. Although the entire arcs agree very exactly with the 
elliptical figure, yet on comparing the parts into which the same 
arc is subdivided, the greatest irregularity is found to prevail. 
This is so much the case in the arc measured between Dun- 
nose and Clifton, in England, that the length of a degree is 
found to decrease in advancing from south to north, instead 
of increasing as the theory requires. To what cause can so 
great an anomaly be ascribed ? In attempting to throw some 
light on the irregularities of the English arc, I have been led 
to examine the operations at Beachy Head and Dunnose; 
and, reserving the discussion of the original question to a fu- 
ture occasion, my present intention is to communicate the 
observations I have made respecting the operations alluded to, 
as they materially affect a capital part of the Survey. 

If a geodetical line be drawn through the station at Beachy 
Head, perpendicular to the meridian of Greenwich, the meri- 
dional distance of the line from Greenwich is, according to the 
Survey, 44888 fathoms : and if a plane parallel to the equator 
be drawn through the same station, this plane will meet the 
meridian 17 fathoms more to the south fj so that the me- 
ridional distance between Greenwich and the parallel of la- 
titude passing through Beachy Head, is 44905 f fathoms. In 
order to find the difference of latitude between the two places, 
the terrestrial arc must be converted into degrees of a great 
circle of the heavens. In the Survey 60851 fathoms is al- 
lowed to a degree, which undoubtedly is too much. For if 
we divide the terrestrial arc measured by Col. Mudge, by its 
amplitude, we shall get 60826 fathoms for a degree at the la- 
titude 52° 2' ; and even this length must exceed a degree at 
the more southern point in the middle between Greenwich 
and Beachy Head. The latitudes of the two places being 
known nearly, I have employed the formula (C), p. 433, Phil. 

* Communicated by the Author. f Survey, vol. i. p. 294. 

X This length should be multiplied by 1 '00007, in order to bring it to a 
general standard for the purpose of comparison with other measurements. 
(Phil. Trans. 1821, p. 93). The same observation applies to all the other 
lengths that occur. I have omitted to make the correction, which how- 
ever does not sensibly affect any of the conclusions. 

Mag. 



Mr. Ivory on a Perpendicular Degrez at Beachy Head. 7 

Mag. for June last, and have found for the length of a de- 
gree, 

At Greenwich 60826 fathoms ; 
AtDunnose 60815; 
and the mean of these, or 60820*5, is the proper rate of con- 
version In the present instance. The difference of latitude 
between Greenwich and Beachy Head will now be 44' 18''; 
and if the latitude of Greenwich be taken at 51° 28' 39", that 
of Beachy Head will be 50° 44' 21". 

The distance between the parallels of latitude passing 
through Beachy Head and Dunnose, as found in the Survey, 
is 7376*5 fathoms; which being converted into degrees, at 
the rate of 60815 fath. to one degree, gives 7' 16"*7 for the 
difference of latitude of the two stations. The latitude of 
Dunnose is therefore 50° 37' 4"*3. 

But as the azimuths at the extremities of the geodetical line 
drawn between the stations are given, we may deduce the 
latitude of Dunnose from that of Beachy Head by another 
method. Let B and D denote the azimuths, and A and A' the 
latitudes, of Beachy Head and Dunnose; then, a and a(\— e) 
being the axes of the terrestrial spheroid, the general pro- 
perty belonging to every geodetical line, will give this equa- 
tion in which the square of s is neglected, 

cos X' sin D cos X sin B 



V 1— 2 « sin (i >.' a/ I — 2gsin*A 

from which we easily derive this formula, log. cos A' = log. 

( C ° S s inD B ) + Ms ( sin9 K - sin3 *')> where M = * 43429 & c -> 
the modulus of the common logarithms. Now, computing by 
this rule, we shall find A' = 50° 37' 5"'65. This result is as 
little different from the former one as can reasonably be ex- 
pected, considering that the methods of calculation are very 
different, and likewise proceed upon experimental data quite 
independent of one another. Both results are confirmed by 
actual observation, Capt. Kater having found 50° 37' 5"*27 for 
the latitude of Dunnose*. We may therefore definitively fix 
the latitudes of the two stations as below : 

Beachy Head 50°44' 21" 

Dunnose 50 37 5 

and it is very improbable that either of these results errs so 
much as 1" from the truth. 

The two latitudes we have found are so little different from 
those in the Survey, as to produce no sensible change in the 
ulterior calculations of the difference of longitude and the 

* Phil. Trans. 1819, p. 413. 

length 



8 Mr. Ivory on the Length of a Degree perpendicular 

length of a degree perpendicular to the meridian. According 
to the Survey, a degree perpendicular to the meridian, at the 
middle latitude between the two stations, is no less than 61 182 
fathoms, or about 200 fathoms more than in the spheroid, 
which has been found to agree so well with all the arcs of the 
meridian that have been most exactly measured. If therefore 
we admit that the method of investigation pursued in the Sur- 
vey is exact, we should have an undeniable proof that the 
spheroid which represents distances on the meridian so ex- 
actly, fails entirely in the case of measurements, the extreme 
points of which are different in longitude. But a little reflec- 
tion will show that the theorem laid down in the Survey for 
finding the difference of longitude is not rigorously exact. In 
the geometrical demonstration of the theorem it is tacitly as- 
sumed, that a geodetical line drawn between two points in 
different meridians, is contained in one plane. But 6uch a 
line has a double curvature ; and the two tangents which ma,rk 
its initial and final directions are not both contained in any 
plane passing through the extreme points of the line. There- 
fore if the difference of longitude, and the latitudes of two 
points on the surface of a sphere and a spheroid, be the same, 
it is not strictly true that the sum of the azimuths in one case 
is equal to the like sum in the other case. The method is 
only an approximation; and it cannot be confidently relied 
on until it is proved that it approximates to the truth without 
sensible error ; which is the more necessary to be done, be- 
cause the whole investigation turns on very small quantities, 
a few seconds in the longitude producing a great variation in 
the length of the perpendicular degree. I have therefore been 
induced to view the matter in a different light, as in this pro- 
blem : To find the difference of longitude of two points on 
the surface of a given spheroid, the latitudes of the points and 
the length of the chord drawn between them, being known. 
In solving this problem we may likewise assume that the two 
points are little different in latitude. 

Let a and a (l—s) represent the axes of the spheroid ; A 
and x' the latitudes of the two points; y the length of the chord 
between them ; and, neglecting the square of e, put 

COS X COS k' 



sinx(l-2i) sin*/(l-2t) 

9. = ^l_2*sin*x' " V 1-2* sin 1 a" 

then ap and au will be the perpendiculars drawn from the 
two points to the polar axis, and a q and a t the perpendicu- 
lars to the plane of the equator. Put a> for the angle between 

the 



to the Meridian at Beachy Head, $ 

the meridians of the two points, or the difference of longitude ; 
then we shall have this equation 

■2L. = (a_ p cos pof+ p* sin 9 to -f- (q — t)* ; 

and, because cos co = 1 — 2 sin 9 -£-, the same equation may be 

thus written : 

£ = (p-uf + (q-tf + 4>pu sin 2 \. 

Now we have, 

p— w=(cosA— cos A') {i+ g— g(cos 9 A + cos 8 X'+cosAcosV)} 

q—t= (sin A— sinA') {1— 2e + e (sin 2 A + sin 2 A' + sin A sin A')}. 

And if we put m= -*-, n = ^~; ty substituting and 

neglecting the term multiplied by i sin 3 n, because n is a small 
angle, we shall get, 

p — u = 2 sin n sin m ( 1 + s —3 e cos 2 7/2 cos 2 74) 
2— * = 2sinw cosw(l — 2e -f3gsin*7» cos 2 w); 
and hence, 

(p— u y+ (q—tf = 4?sin«» A + 2ssin 2 m — 4ecos 9 7tt)) i 

or, which is the same thing, 

(^-tt) a + (?-*) 2 = * sin 9 -%£ (l - 1 - 3g cos (A + A')). 
Again we have, 

cos X COS X' 

pu = 



1— t (sin 3 X + sin* x') 

but as A and A' are nearly equal, we may take 2 sin 9 #£* = 
1 — cos (A-f A') for sin 2 A + sin 9 A'; consequently, 

cos X COS X' 
f U ~ l-t + icos(X-|-xy 

Lastly, we have a =jt?A ; A being the length of a degree on 
the equator of the spheroid, and p the number of degrees in 
an arc equal to the radius. All the values being substituted, 
we get, 

y l • a*— x' /, „ /. , »i\\ cos X cos x' sin* g 

— — = sm 2 ( 1— e— 3gcos(A + A') )+ I 

4;*a» 1 V v '/~ 1-i-f icos(x-fx') ♦ 

From this expression the arc w may be computed by means 
of these formulas ; viz. 

t . , /2nA . x — x' \ Mi 3Ms . n 

Log. sin u = log. f — - — sin — — j — 5- cos ( x + x " 

New Series. Vol. 4. No. 19. July 1828. C Log. 



10 Mr. Ivory on a perpendicular Degree at Beachy Head. 

t • " i /ycosu\ , ! , L ',. Mi Me 

Log. sin - = log.( — r ) - i log. (cos A cos A') - — + -y- 

xcos(X-t-V). 

Applying this method to the case of Beachy Head and 
Dunnose, we have the latitudes as before determined : the 
chord between them, or y, is equal to 339397*6* feet, or 
56566'3 fathoms : and, with these data, we get, in the same 
spheroid as before, 

co = 1° 27' 5"*78, 
which is 18" more than according to the Survey. 

Now the length of a geodetical line drawn from Beachy 
Head at right angles to the meridian, and limited by the me- 
ridian of Dunnose, is 3361 19f feet, or 56020 fathoms. Let 
A be the amplitude of this arc ; then we get, by the usual 
method, 

Tan A = cos \ tan w, A = 55' 7"'57. 
And if we lengthen the arc in the proportion of the amplitude 
to 1°, we shall get 60973 fathoms for a degree perpendicular 
to the meridian at the latitude of Beachy Head, which is 200 
fathoms less than according to the Survey. This result may 
be verified by comparing it with the length of a perpendicular 
degree at the given latitude. The expression of this degree is, 

/V /l_(2f_^)sin^A I \2 2/5 

and, by substituting the numbers, the length comes out 60974, 
only one fathom more than what has been deduced from the 
measurements in the Survey. 

The difference of longitude we have found is only 1" more 
than what Dr. Tiarks has assigned (Phil. Trans. 1824) as re- 
sulting from his chronometrical observations. This is no doubt 
a great confirmation of the theory, but it has not the weight 
of a direct experiment; because it is deduced from the ob- 
served difference of longitude between Dover and Falmouth, 
by making a proportional allowance, which is a method of 
proceeding in some degree precarious. As there is no doubt 
about the accuracy of the observed quantities in the Survey, 
it might be worth while to compute from the data it contains, 
by rectifying all the calculations, the difference of longitude 
between Dover and Falmouth, in order to compare it with the 
result obtained directly by experiment. 

The main purpose of this> article is now accomplished. It 
has been clearly proved that the same spheroid which repre- 

* Survey, vol. i. p. 295. f Ibid. p. 297. 

sents 



Mr. Walker -oh the Artificial Production of Cold. 1 1 

sents with so much accuracy distances on the meridian, is no 
less exact when applied to measurements perpendicular to the 
meridian. At least this is the case in England in the instance 
we have examined ; and a little time will show whether the 
same conclusion is confirmed or contradicted by the geode- 
tical operations now executing on the continent. 

June 13, 1828. J. IvORY. 



IV. Additional Remarks on the Artificial Production of Cold. 
By Richard Walker, Esq., of Oxford. 

To the Editors of the Philosophical Magazine and Annals. 
Gentlemen, 
PERCEIVING an erratum in my communication inserted 
■*■ in the Philosophical Magazine for the present month, 
which renders my meaning rather obscure, I request you will 
have the goodness, in your next, to correct it thus : — at page 
404?, 8th line from the bottom^r " freely" — read "freshly." 

I shall avail myself of this opportunity to present, in a cursory 
way, a few additional observations. 

The drier and finer the mixed powder of sal ammoniac 
and nitre is, the better ; and the pulverization is best effected, 
in the first instance, with a heated pestle. Glauber's salt in 
an efflorescent state, or which by long keeping or from ac- 
cess of air has changed to a powder, is unfit for the purpose ; 
in this state producing heat by solution in water. The best 
way of preparing the frigorific mixture is by previously pla- 
cing the powdered Glauber's salt, and giving it a level surface, 
at the bottom of the vessel, and upon that the mixed powder 
of sal ammoniac and nitre ; adding first about half the quan- 
tity of water, and immediately after the remaining portion, 
stirring the whole together each time. The vessel containing 
the powdered salts, as above stated, may remain thus any con- 
venient time before adding the water. [Care must be taken 
to stir the evaporating mixture towards the end of the process, 
and not to urge it too far.] Nitre being a much cheaper ar- 
ticle than sal ammoniac, more easily reduced to powder, and 
producing about 16 degrees of cold by solution in water, may 
supersede the use of the mixed powder for cooling the watef 
in which wine is placed. This powder, moreover, is useful, 
occasionally, as an addition to mixtures of ice and salt, to in- 
crease the power and accelerate the process. 

The proportions of the articles given in my former paper 
are adapted to the temperature of 50° ; at a higher tempera- 

2 C ture, 



1 2 Observations on the Geology 

ture, of course, the water will dissolve a somewhat larger por- 
tion of the salts, and the effect will be proportionably greater. 
Thus the most powerful mixture, given in my table of frigo- 
rific mixtures, consisting of phosphate of soda, nitrate of am- 
monia, and diluted nitric acid, will, when mixed at the tem- 
perature of 50°, produce a cold of 21° below 0; and if mixed 
in due proportions at 100°, it will produce, in an instant, a 
cold of 20°; viz. a reduction of eighty degrees. By means of 
this mixture, as I have been informed, water has been frozen 
solid " under the line." I am, Gentlemen, 

Your most obedient servant, 
Oxford, June 10, 1828. RlCHARD WALKER. 



V. Observations on the Geology of the Hyderabad Conntiy*. 

r T , HE country around Hyderabad is composed entirely of 
■*■ granite, intersected by quartz, which generally runs north 
and south ; and by trap, which has no definite direction. 

The hills are generally in ridges. In some instances they 
are insulated, of a mamillary form, or abrupt and precipitous. 

The ridges are covered with detached masses of rock, and 
frequently (when seen at a little distance) hare more the ap- 
pearance of heaps of loose stones than of solid hills. The 
mamillary hills are almost always devoid of vegetation, having 
a smooth surface, with large detached lamellae lying loosely 
on their sides, and apparently ready to slide or tumble down 
oh the slightest impulse into the neighbouring valleys. 

The insulated hills often present on one or more sides a 
smooth, perpendicular surface, which makes a very sudden 
curve at the top, or undulates, and thus contracts the summit 
of the hill. 

Sometimes we find the surface of the granite forming part 
of an immense curve, and rising very gently and to a small 
height above the surrounding plain. In other instances it is 
waved, and presents a great variety of outline. 

Huge blocks of granite are every where strewed over the 
country, and are often piled over each other in the valleys, or 
on the sides or summits of the hills, giving rise to the most 
fantastic shapes, and often closely resembling ruined buildings. 
It is not uncommon to see three or four immense masses of 
granite placed above each other, with their surfaces nicely 
adapted, having somewhat the appearance of the ruin of an 

* From the Transactions of the Literary Society of Madras. Part i. page 79- 

ancient 



of the Hyderabad Country. 13 

ancient column, which might be expected to be soon levelled 
with the ground, by the agency of the weather. 

All the granite of Hyderabad is stratified or lamellar. The 
strata and lamellae vary in thickness, from less than an inch 
to many feet. They have no definite direction or dip ; but 
are generally curved, sometimes to a small extent horizontal, 
waved, or perpendicular. 

The granite on one side of a small hill, close to that of 
Shapoor, near the Beema, has the appearance (when seen at 
a little distance) of being columnar; but when it is examined 
more closely, it is evident that this appearance arises from the 
following circumstance : — The lamella? of the granite are per- 
pendicular, and had formerly made a very rapid curve at the 
top. By the influence of the weather, this curve has been 
worn down, and has thus allowed the inferior perpendicular 
part of the lamellae to separate a little from each other ; and 
accordingly, when seen transversely, they closely resemble 
columns* 

The internal structure of the granite is almost always small 
granular*. The proportions of its constituent parts vary ex- 
ceedingly. In many instances the mica is entirely wanting ; 
and when situated near quartz, the granite and quartz are fre- 
quently found to pass gradually into one another. 

The colour of the granite is sometimes red, in other in- 
stances gray, white, or blackish, according to the colour of 
the felspar, and according as one or other of the constituent 
parts predominate. Different colours often occur at very small 
distances in the same stratum, or lamella ; and it is not un- 
common to meet with strata of different colours resting on one 
another. 

Frequently nodules and small veins of granite, having a very 
large proportion of mica, and occasionally veins of pure mica, 
are found in the common granite, from which (in some cases) 
they easily separate when the rock is broken ; but in other in- 
stances they are intimately connected with, and gradually pass 
into the surrounding rock. 

The quartz and trap, by which the granite is every where 
intersected, occur under the form of mountain masses and 
veins. Sometimes, though more rarely, the trap is found in 
nodules. The veins vary from a few inches to many miles in 
length. Their junction with the bounding rock is sometimes 
distinct, while in other cases they are intermingled at their 
sides with the neighbouring granite. 

The quartz is sometimes intermixed with felspar, which 

* I will not venture to assert that it is invariably small granular, for my 
observations have not been sufficiently extensive. 

makes 



14 Observations on the Geology 

makes it much more perishable than when pure ; and accord- 
ingly when this is the case, we generally find it wearing down 
and becoming disintegrated. 

The trap is found under the forms of greenstone and basalt. 
It is either tabular, massive, or in globular concentric lamellar 
concretions, with occasionally disseminated crystals of augite. 
The globular variety is very easily acted on by the weather, in 
consequence of which it is in many situations completely dis- 
integrated and converted into a black soil. In some places, 
where this variety of trap occurs in great abundance, it is worn 
down into small detached globular masses, which are every 
where strewed over the ground. 

Almost all the granite of Hyderabad is quickly disintegrated 
when exposed to the atmosphere, and assumes a globular or 
irregular form when decomposing. Every where there are 
immense accumulations of disintegrated granite, at the bottom 
of the hills and in the valleys. I have known instances of 
wells being dug through it to the depth of sixty feet, without 
penetrating to the original rock. At the surface of the ground 
it is loose, but at considerable depths it is more or less per- 
fectly consolidated ; and the deeper we penetrate into it, the 
more perfect is its cohesion. It is not uncommon to meet with 
small quartz veins running through this consolidated debris, 
in various directions ; and in many instances there is an ap- 
pearance of imperfect stratification. 

All the low valleys are covered by a plastic blackish co- 
loured soil, generally known by the name of cotton ground. 
It varies in depth from a few feet to many fathoms ; and when 
a section of it is examined (which can be done in those places 
where it is worn down by rivers), it is generally found distinctly 
arranged in strata, which are sometimes separated by thin 
layers of sand or gravel. These strata vary in thickness, are 
sometimes horizontal, in other instances waved, or more or 
less inclined to the horizon. 

I have not had an opportunity of analysing this clay ; but 
that its composition is by no means uniform, may be inferred 
from the circumstance of its outward appearance varying con- 
siderably in different situations. Sometimes it is of a blackish 
gray colour, and is somewhat friable; while in other cases it has 
a yellowish or whitish gray colour, and is much more cohesive. 

At first sight one would imagine, that the Hyderabad coun- 
try has at one time been subjected to the agency of some great 
destroying cause which has fractured and torn asunder the 
hills, and precipitated their fragments into the neighbouring 
plains. But upon closer examination, I think we are naturally 
led to conclude, that the gradual operation of causes which 

are 



of the Hyderabad Country. 15 

are still in existence, have produced those effects which many 
would attribute to the operation of very powerful agents. In 
short, I believe that all these phenomena are the result of the 
long continued agency of the weather. 

It is well known that masses of granite which have been 
detached from the neighbouring hills, are worn down and dis- 
integrated by the weather ; and also, that the lamella? or strata 
of granite, which still retain their original situation, when ex- 
posed to the atmosphere, split and slide down into the adjoin- 
ing valleys*. Since then we have ocular proofs of the hills 
being broken down and disintegrated by the weather, and since 
these effects are never known to be produced by any other 
cause, can we hesitate to conclude, that all the accumulations 
of debris and detached masses of granite have originated in 
the same manner? Effects are daily produced under our im- 
mediate observation, exactly similar to those to be accounted 
for ; and although, at first sight, the magnitude of the effect 
may appear out of proportion to the cause, yet the latter will 
be sufficiently adequate, if it be admitted, that it has continued 
to operate through an immense lapse of ages, — a circumstance 
which no one can possibly doubt. 

It may be argued, that earthquakes are much more power- 
ful than the slow agency of the weather, and more adequate 
to produce the effects under consideration. Earthquakes are 
certainly among the most powerful causes with which we are 
acquainted, in effecting changes on the crust of our globe; yet 
their effects are very different from those I am attempting to 
account for. The lamellae and strata of the Hyderabad gra- 
nite gradually break up and scale off, exactly in the same 
manner as we detach successively the layers of an onion. But 
this appearance is very different from what we should be led 
to expect, had it been produced by earthquakes ; for in that 
case the ruined appearance of the granite would not have been 
confined to the surface, but would have extended to the centre 
of the hills. 

One of the most curious and interesting appearances in the 
geology of the Hyderabad country, is that already mentioned, 
of large masses of granite resting firmly on one another, in 
the form of ancient ruins. These are quite different from the 
masses which have been detached from the neighbouring hills, 
and afterwards heaped confusedly together ; for their surfaces 
are closely adapted, and four or five masses are often placed 

* The same effects arc produced upon granite in India, by great degrees 
of heat, alternating with moisture, as those that are produced upon granite 
in Che Alps of Switzerland, by intense frost succeeded by thaw. 

firmly 



16 Observations on the Geology 

firmly on each other, as if by art. Sometimes they occur on 
the summit of a hill ; in other instances, they are found com- 
pletely insulated in a plain. 

From all the circumstances connected with these masses, I 
think we must conclude, that at present they continue to oc- 
cupy their original positions ; that they are the slight remains 
of strata which have been gradually worn down all around 
them; and that they now stand as monuments of what the 
depth and nature of these strata formerly were. This con- 
clusion is as legitimate as that the strata on the opposite coasts 
of England and France were once continuous, deduced from 
the circumstances of their corresponding in their nature, rela- 
tive position, and direction. In order to show more clearly 
on what grounds I rest the above conclusion, I will consider 
the subject a little more in detail. We often observe a hill 
composed of successive strata or lamellae, the most superficial 
of which are more or less detached and broken up ; that round 
its base are large accumulations of debris and detached frag- 
ments ; and that on its summit are three or four masses resting 
firmly on one another, with their surfaces accurately adapted, 
except perhaps at their edges, where they have been affected 
by the weather. Now as we have here ocular proofs that a 
number of strata (which formerly belonged to this hill) have 
been detached and worn down ; and as it would almost amount 
to an absurdity to suppose that the masses on the summit have 
been conveyed from a distance, and placed there with their 
surfaces accurately corresponding, we must conclude that the 
hill was formerly much higher than at present ; and that while 
a number of its strata have been gradually worn down and 
swept from its surface, the masses at its summit (which at one 
time formed part of these strata) have remained steadfast in 
their original situations, probably from their being more du- 
rable, or from their horizontal position. It is very evident 
how this must happen, when it is recollected how the lamellae 
of the granite are broken down and separated from those be- 
neath. They split in various directions, and in this manner 
form a number of separate masses, which slide down the sides 
of the hill. Now, it is clear, that the part of the lamellae on 
the summit has every chance of remaining stationary, for it 
rests horizontal!}'; and while all the detached pieces around it 
slide down into the neighbouring valleys, it will maintain its 
situation. When the next bed is exposed to the atmosphere, 
and becomes detached from that beneath, of course the part 
on the summit immediately under the fragment which remained 
stationary in the first instance, has every chance of continuing 
in its situation ; and thus in the course of time the appearance 

above 



of the Hyderabad Country. 1 7 

above described will be produced. The same explanation is 
to be given of the origin of those masses which are found in- 
sulated in the plains. I imagine that they rest on the summit 
of what were formerly hills, but which are now completely 
buried under their own ruins. 

The peculiar arrangement and structure of the quartz and 
trap in the granite of Hyderabad, afford abundant proofs of 
the correctness of Mr. Jameson's views of the formation of 
veins, viz. that they are of simultaneous formation with the rock 
which they traverse. In the Hyderabad country, we find 
quartz and trap under the forms of veins, nodules, and moun- 
tain masses, sometimes perfectly distinct from the surrounding 
granite, in other instances intermingling with it, and gradually 
passing into it. With these facts before us, can we doubt that 
these rocks are of cotemporaneous origin ? 

I have often been surprised that theorists, in their attempts 
to explain the various phsenomena presented by the crust of our 
globe, have never employed causes of whose existence we have 
certain proof, and with whose effects we are well acquainted ; 
but on the other hand have assumed the existence of causes of 
which we never had experience, and whose effects we never 
witnessed. Huttonians assume the existence of a central fire*, 
which they contend to be the cause of the consolidation of the 
debris of former hills, and consequently of its conversion into 
new rocks. But that such a supposition is by no means ne- 
cessary, is evident from the circumstance, that this consolida- 
tion often takes place without the assistance of heat. I have 
already mentioned that the debris of the Hyderabad granite 
becomes gradually consolidated, merely by pressure; and that 

• The heat of the Huttonians must be an extremely convenient as well 
as powerful agent, for it can both liquefy and consolidate bodies. At one 
time it can inject a flood of melted basalt into the superincumbent rocks ; 
at another time it can consolidate sandstone, and other secondary rocks, at 
the bottom of the ocean. There are two facts which are very hostile to 
this theory ;— first, the greater the pressure, the greater is the obstacle to 
the fusion of a body ; second, the greater the heat, the greater is the op- 
position to the consolidation of a body. Now, the Huttonian theory requires 
that the two great agents which it employs, viz. heat and pressure, should 
act in concert ; the heat to liquefy, or (as occasion may require) to consoli- 
date bodies ; the pressure to prevent the escape of volatile substances, 
which might be otherwise dissipated. These two forces, however, must op- 
pose each other ; for heat is one of the most powerful agents with which 
we are acquainted in separating the particles of bodies, while pressure 
brings them closer to each other. The pressure of the ocean, therefore, 
although in all probability equal in itself to consolidate the debris of former 
hills into new rocks, may not be sufficient for that purpose, if opposed by 
a heat sufficiently powerful to liquefy granite and trap ; and a heat that 
would be equal to the melting of trap at the earth's surface, would be by 
no means adequate to do so under the pressure of mountains. 

New Series. Vol. 4. No. 1 9. July 1 828. D the 



18 Obsetvatiofis on the Geology of the Hyderabad Country. 

the greater the pressure, the more perfect is the consolidation. 
This is a power with whose effects we are well acquainted. 
By bringing the particles of bodies closer to each other, pres- 
sure becomes a powerful cause of consolidation ; and I am 
convinced that without the assistance of any other agent, it is 
one of the most general and powerful causes of the changes 
which happen in the mineral kingdom. 
Camp Kulle-dghee, 1st July, 1824. 

Rock Specimens from the Vicinity of Hyderabad. 

The specimens from No. 1. to 13. are the most common va- 
rieties of granite in the Hyderabad country. 

1. 2. S. 4. are from Bowenpilly, several miles to the north 
of the city of Hyderabad. 

5. and 6. are from Shumshabad, about twelve miles west of 
the city ; 5. is from a stratum about half an inch thick, resting 
on that from which 6. was taken. 

The specimens from 7. to 20. inclusive, are from Moula 
Alley. 

Moula Alley hill is a large mass of lamellar granite, of a 
mamillary form, having a smooth surface, perfectly devoid of 
vegetation, except on a very few spots, where the disintegrated 
granite has formed a superficial bed of soil. The lamellae of 
the granite in some places scale off, split in various directions, 
and gradually slide or fall down into the neighbouring valleys, 
where they continue to break down into still smaller masses, 
until they become completely disintegrated. The lamellae 
vary from a few inches to many feet in thickness. 

9. and 10. occur in great abundance in the hill of Moula 
Alley. 

12. Red granite with very little mica. The bed from which 
this specimen was taken, rests upon No. 9. 

13. Granite with the mica in large concretions. 

14. White granite without mica. 

15. Granite containing a vein of mica. 

16. A variety of granite with mica predominating, from a 
nodule in one of the common kinds of granite. 

17. From a nodule in the granite. 

18. From a nodule of trap in the granite. 

19. From a trap vein about twelve feet thick, with part of 
the contiguous granite adhering to it. 

20. Trap passing gradually into granite. 

21. 22. 23. 24. from a vein of quartz in the granite, ex- 
tending from near the city of Hyderabad, several miles in a 
northerly direction. This vein is of a very considerable mag- 
nitude. 



Mr. S. Sharpe on the Figure of the Cells of the Honeycomb, 19 

nitude. Being of a more durable nature than the granite, it 
has been much less affected by the weather ; and while the 
granite in its vicinity has been worn down, and in a great 
measure levelled, it has remained in the form of a ridge. In 
several places the quartz is intermixed with felspar, which 
makes it more liable to be acted on by the weather ; and ac- 
cordingly we find that in these places it is worn down, and the 
continuity of the ridge is thus interrupted. 

25. From a trap vein which extends from the cantonment 
of Secunderabad in a westerly direction. When it approaches 
the quartz vein described above, it divides into two or three 
branches, and penetrates the quartz in several places. 

26. Red granite without mica, from the vicinity of the quartz. 

27. Quartz and felspar in large concretions, from the vicinity 
of the quartz. 

28. Granite with epidotic veins, associated with the quartz, 
near the place where it is penetrated by the trap. 

29. 30. Granite without mica found near the quartz. 

31. Disintegrated granite from a depth of four or five feet 
from below the soil, beginning to consolidate. 

32. From immediately under the soil. 

33. Nodular basalt from a trap vein. 

34. Nodules of trap found loose on the surface of the ground. 

VI. On the Figure of the Cells of the Honeycomb. By 

Samuel Sharpe, Esq. F.G.S.* 
T> EAUMUR mentions, in his History of Insects, vol. v. 
■"• p. 39, that he employed Maraldi to measure a cell of a 
bee's honeycomb, and Kcenig to calculate what the propor- 
tions of the three*sided pyramid at the end should be, in order 
that the whole cell might be made with the least materials ; it 
being easily shown that the contents of the cell would be the 
same, whatever the height of the three-sided pyramid, even 
if = o, in which case the prism would have a plain end. 

Their reports nearly agreed ; but the difference still is not 
to be overlooked, as will be seen in the angles of the parallelo- 
grams of the pyramid : 

Maraldi's measurement 109° 28' and 70° 32' 

Kcenig's calculation 109 26 Vo 34 

And neither naturalists nor mathematicians have accounted 
for the difference. 

As, from the nature of the materials, the angles can hardly 
be measured by reflection from the sides with a reflective go- 
niometer, we have no better means of measuring than Maraldi 
* Communicated bv the Author. 

D2 had, 



20 Mr. S. Sharpe on the Figure of the Cells of the Honeycomb. 

had, and shall therefore consider his measurement to have been 
correct. 

By the fluctional theorem de maximis et minimis, the calcu- 
lated angles appear to be wrong, and should be 109° 28' 16", 
and 70° 31' 44?" ; which must be held to agree with the measure- 
ment ; as no one would pretend to make that more accurate 
than to the nearest minute, and the difference is much within 
those limits. 

Kcenig's paper was read before the Academie des Sciences 
at Paris in 1739, and the results are mentioned in their Trans- 
actions for that year ; but as his working is not added, I can- 
not compare mine with his to see where the error lies. 

As it cannot be held unimportant to show that bees build 
their cells exactly in the form which, at length, by the dif- 
ferential calculus, we find to be best ; and as I cannot expect 
my assertion to be preferred to that of Kcenig, — I add the 
working at length. 

1st. As of those figures which can be brought together 
without leaving any interval, the hexagon is that which has 
the greatest number of sides, it is clearly the one which needs 
the least materials to inclose a given space. 

2ndly. If a range of hexagonal cells be met by a range 
of similar cells, and no space be wasted, each cell must end 
either with a three-sided pyramid, or with a plane at right an- 
gles to the sides (i. e. a pyramid whose altitude = 0). 

Query. What must be the altitude of the pyramid, in order 
that a cell of a given prism and given solid contents may be 
constructed of the smallest quantity of materials? 

Let fig. 1. be any such regular three-sided pyramid on a 
six-sided prism. 



Fig. 1. 



Fig. 2. 





Fig. 2. the same prism with a plain end at right angles to 
the sides («'. e. the altitude of the pyramid = 0). 

Fig. 3. 



Mr. S. Sharpe on the Figure of the Cells of the Honeycomb. 21 

Fig. 3. the plain end of the above. Join the alternate an- 
gles ACE to the centre g, and to 
each other. Then if the centre g Fig. 3. 

be raised and ACE remain fixed, 
the other angles (solid angles in 
the prism) BD and F will be 
lowered, and the solid contents of 
the cell will remain the same. 

Again, by comparing fig. 1 
and 2. we see that though the py- 
ramid needs more materials than 
the plain termination, yet the sides 
of the former prism need less than 
those of the latter by the six little 
triangles Amb, 

Now let AB(=mb)be a 

A m (the altitude of the pyramid) ... x 
AH (half of AC) d 

Ab= V a* + x* 

Amb = — - 

2 




Hb = s/ cC l + x*—d\ and the quantity which 
we wish to be a minimum is 

3(AgCb)-6(Amb) = 6d \/ a* + x t — d i ]- 3 a x whose 

fluxion is SdQ* + x 2 — d 2 ^xx — 3 ax — 
2dx(a t +x i -d 2 Y h = a 



2dx = a(a?+x*' 
4.d*x 2 z=;a 4 +a?x 2 



■a 2 d? 



ai—cfld 1 
Ad* -a* 



but d* = a*-£- = 



3(1* 
x = 



therefore x*= 



3a« 

4 



3 a* -a* 



and 



•T 



Ab = a v-g-j 



and Ab : AH : : radius : cos. HA b = 






'A 



COS 



35° 15' 51"-86, and the angle g Ab = 70° 31' 44" nearly. 

AgC = 109 28 16. 

VII. Che- 



[ 22 ] 

VII. Chemical Examination of the Oxides of Manganese. By 
Edward Turner, M.D. F.R.S. Ed. Professor of Chemistry 
in the University of London^ and Fellow of the Royal College 
of Physicians qf Edinburgh.* 

TT was originally my intention, in entering on this inquiry, 
-*• merely to ascertain the composition of the ores, the mine- 
ralogical characters of which have been so ably delineated by 
Mr. Haidinger in the preceding paper f. I had advanced, 
however, but a short way in the investigation, when my pro- 
gress was arrested by doubts both as to the manner of con- 
ducting the analyses, and as to the mode of calculating their 
results. In this uncertainty I found it necessary to extend my 
original plan, with the view of supplying by my own researches 
what appeared to be not sufficiently established by the labours 
of other chemists. I have accordingly divided the essay into 
two parts; attempting in the first division to ascertain the 
atomic weight of manganese, and the composition of the arti- 
ficial oxides of that metal; and in the second, applying the 
facts thus established to illustrate the chemical constitution of 
the native oxides described by Mr. Haidinger. 

Part I. 
On the Atomic Weight of Manganese. — Analysis of the Car- 
bonate of Manganese. 
A pure carbonate of the protoxide of manganese was pre- 
pared in the following manner. The dark brown mass left in 
the process for procuring oxygen gas from the common per- 
oxide of manganese by heat, was mixed with a sixth of its 
weight of powdered charcoal, and exposed to a white heat for 
half an hour. The protoxide thus formed was dissolved by 
muriatic acid, the solution evaporated to dryness, and the re- 
sidue kept for some time in a state of fusion at a red heat. 
The resulting chloride of manganese was re-dissolved by di- 
stilled water; and after being filtered, was found to contain 
no impurity except a little lime, which was separated by the 
oxalate of potash. The manganese was then precipitated by 
a solution of the bicarbonate of potash, and the carbonate of 
manganese was carefully edulcorated and collected on a filter. 
After removing the upper layer, which had become rather 
brown by exposure to the air, the white carbonate was kept 
in a vacuum along with a vessel of sulphuric acid until it be- 

* From the Transactions of the Royal Society of Edinburgh. 

f On a future occasion we propose to give Mr. Haidinger's paper here 
alluded to, and also Dr. Turner's analyses of the ores which he has de- 
scribed.— Edit. 

came 



Dr. Turner's Examination of the Oxides of Manganese, 23 

came quite dry. The salt thus prepared yielded a colourless 
solution, without any residue, when put into dilute sulphuric 
acid, and was therefore free from the red oxide of manga- 
nese. 

Of this carbonate 8*805 grains were heated to redness in a 
green glass tube, and the water collected in a tube filled with 
fragments of the chloride of calcium. The quantity of water 
procured in this way amounted to 0*742 of a grain, equivalent 
to 8*427 per cent. 

The proportion of carbonic acid was estimated by noting 
the loss of weight which the carbonate of manganese experi- 
ences when dissolved in dilute sulphuric acid. This mode of 
analysis, as commonly performed, is inaccurate ; because the 
liquid retains carbonic acid in solution, while the gas during 
effervescence carries off with it an appreciable quantity of wa- 
tery vapour. But when performed with the precautions which 
I adopted, it yields uniform results, and is susceptible of great 
precision. A known quantity of the carbonate is placed in a 
small glass phial fitted with a tight cork, in which two tubes 
are inserted. One of these tubes descends to near the bottom 
of the phial and then bends slightly upwards, so as to admit 
of the acid being gradually introduced without affording an 
exit to the gas. The other communicates with a tube filled 
with chloride of calcium, over which all the carbonic acid gas 
passes before escaping into the air. As soon as the efferves- 
cence has ceased, the carbonic acid retained by the solution 
is driven off by causing it to boil during the space of a few 
minutes ; and the gas is by the same means expelled from the 
interior of the phial, into which on cooling the atmospheric 
air is admitted by the tube for introducing the sulphuric acid. 
The carbonic acid gas remaining with the chloride of calcium 
is replaced by atmospheric air, which is introduced by in- 
haling at one extremity of the tube while the other is open. 
The upper part of the tube for introducing the dilute sul- 
phuric acid, when not required to be open, is of course closed 
with a cork in order to avoid loss by evaporation. 

It was found by means of the preceding process that 20*68 
grains of the carbonate, when dissolved in dilute sulphuric 
acid, lose precisely 7*18 grains, or 34*72 per cent of carbonic 
acid. It is accordingly composed, in 100 parts, of 

Protoxide of manganese 56*853 

Carbonic acid 34*720 

Water 8*427 

100*000 

Regarding 



24 Dr. Turner's Chemical Examination 

Regarding 22 as the equivalent of carbonic acid, we have the 

following proportions :— As 34*72 : 56*853 : : 22 : 36*024. 

According to this analysis, 36 may be safely adopted as the 
combining proportion of the protoxide of manganese; and 
presuming the elements of this compound to be in the ratio of 
one equivalent of oxygen to one equivalent of metallic man- 
ganese, 28 will be the equivalent of the latter. This result, 
with respect to the acid and base, corresponds exactly with 
the analysis of Dr. Thomson, as mentioned in his First Prin- 
ciples of Chemistry, vol. ii. p. 350. It differs considerably 
from the proportions stated by Dr. Forchhammer. (Annals 
of Philosophy, N. S. vol. i. p. 54.) According to this chemist, 
33*05 parts of carbonic acid combine with 51*755 parts of the 
protoxide of manganese, a proportion which would fix 34*45 
instead of 36 as the equivalent of the protoxide. This esti- 
mate is certainly erroneous ; and Dr. Forchhammer appears 
to have fallen into the mistake by supposing that the carbonate 
of manganese is converted by a red heat into the deutoxide, 
whereas according to my experiments the red oxide chiefly is 
then generated. 

It appears doubtful whether the water found by analysis in 
the carbonate, after being dried in vacuo with sulphuric acid, 
is mechanically retained by it or is in a state of chemical union. 
As the proportion is not atomic, it is probable that the car- 
bonate is really anhydrous. If the ratio were as 58 to 4*5 in- 
stead of 5*337, the salt might be regarded as a compound of 
two equivalents of the carbonate of manganese and one equi- 
valent of water. 

Composition of the Sulphate of Manganese. — The most re- 
cent analyses of the sulphate of manganese are by Dr. Forch- 
hammer and Dr. Thomson, described in the works already 
quoted. Dr. Forchhammer precipitated the acid of a known 
quantity of the neutral sulphate of manganese by the nitrate 
of baryta, and inferred from the weight of the precipitate, that 
100 parts of the sulphate of manganese are composed of 54*378 
parts of sulphuric acid and 45*622 of the protoxide. Accord- 
ing to this analysis, the atomic weight of the protoxide is 
33'56, a number which is surely very far from the truth, and 
is inconsistent with the equivalent of that oxide derived from 
Dr. Forchhammer\s own analysis of the carbonate. 

Dr. Thomson analysed the sulphate of manganese by mix- 
ing that salt in atomic proportion with the muriate of baryta, 
and found, that, after the insoluble precipitate had sub- 
sided, no trace of sulphuric acid or baryta could be found in 
the solution. From this experiment he infers that 36 is the 

equivalent 



of the Oxides of Manganese. 25 

equivalent of the protoxide. I am of opinion that the num- 
ber assigned by Dr. Thomson is correct, but I am not so cer- 
tain that the means by which he arrived at this conclusion are 
altogether free from objection. The principle of his method 
is unexceptionable, especially if the quantity of the precipitated 
sulphate be carefully observed at the same time ; but it is es- 
sential to accuracy that the atomic weight of baryta be per- 
fectly established. Dr. Thomson supplied this element in the 
inquiry in the following manner. He dissolved 88 parts or one 
equivalent of sulphate of potash, and 106 parts, or what he 
considered one equivalent, of the chloride of barium in se- 
parate portions of distilled water, and then mixed the solu- 
tions together. After the precipitate had subsided, the super- 
natant liquid was found to contain no trace either of sulphu- 
ric acid or baryta. It hence follows, if no error is committed, 
that 70 is the true equivalent of barium. But in a recent 
number of PoggendorfFs Annalen der Physik und Chemie 
(vol. viii. p. 5), Berzelius denies the accuracy of the experi- 
ment. He declares that after mixing together the sulphate of 
potash and chloride of barium in the proportions mentioned 
by Dr. Thomson, 2^ per cent of the chloride of barium re- 
mained in the residual liquid ; and on repeating this experi- 
ment for my own information, I certainly found that the whole 
of the baryta was not precipitated. I wish it to be distinctly 
understood, however, that I do not confidently rely on the 
accuracy of my result, having been hitherto unable, from want 
of leisure, to examine the subject with that care which I deem 
necessary before attempting to decide a point in dispute be- 
tween chemists, for whose analytical attainments I entertain 
such high respect. Dr. Thomson will doubtless feel the ne- 
cessity of verifying his conclusions without delay; since an 
error in the atomic weight of barium will at once vitiate an 
extensive series of his most elaborate analyses. My own ob- 
servation, however, combined with the remark of Berzelius, 
has induced me in the mean time to secure my own researches 
as much as possible from any uncertainty respecting the atomic 
weight of barium, and I have been therefore induced to ascer- 
tain the composition of the sulphate of manganese syntheti- 
cally rather than by analysis. 

Nine grains of pure protoxide of manganese, prepared from 
the red oxide by means of hydrogen gas, were dissolved in 
dilute sulphuric acid, the solution was slowly evaporated to 
perfect dryness in a platinum crucible, and the dry salt exposed 
for half an hour to a red heat. It then weighed 19'01 grains ; 
and regarding the increase in weight as owing to the acid com- 
bined with the protoxide, the resulting sulphate must consist 
New Series. Vol. 4. No. 19. July 1828. E of 



26 Dr. Turner's Chemical Examination 

of 9 grains of the protoxide of manganese, and 10*01 grains of 
sulphuric acid. The atomic weight of the protoxide indicated 
by this process, is 35*96. The experiment was repeated with 
4*855 grains, and the resulting sulphate weighed 10*26 grains, 
indicating 35*93 as the equivalent of the protoxide of man- 
ganese. 

As some chemists may doubt the accuracy of this process, 
I shall attempt to show the grounds on which its merits are 
to be estimated. Dr. Thomson says it is scarcely possible to 
expel all the water from the sulphate by means of heat, without 
at the same time driving off some of its acid. It is indeed very 
easy to effect the decomposition alluded to by Dr. Thomson ; 
but I found no difficulty, by slow evaporation and raising the 
fire gradually, to keep the salt at a red heat for an hour or longer 
without decomposing a particle of it. If the heat should ac- 
cidentally become so intense as to decompose a little of the 
salt, the defect is easily remedied by adding a drop or two of 
acid, and replacing the crucible in the fire. 

Dr. Forchhammer has judiciously remarked, that in expel- 
ling an excess of sulphuric acid, a portion of the salt is very 
apt to be carried off mechanically by the acid vapour and lost. 
This accident has occurred to myself, and always happens when 
a large quantity of free acid is rapidly expelled. By employ- 
ing a slight excess of acid, and raising the heat slowly, all loss 
from this cause may easily be avoided. 

The dry salt obtained in my experiments was white, and 
dissolved readily and completely in distilled water. 

Like many other neutral metallic solutions it reddened de- 
licate litmus paper. It was nevertheless quite neutral ; for a 
single drop of a dilute solution of potash occasioned a preci- 
pitate which was not in the slightest degree redissolved by 
agitation. 

Analysis of the Chloride of Manganese, — In an excellent pa- 
per published in the Philosophical Transactions for the year 
1812, Dr. John Davy states the chloride of manganese to be 
composed of 54 parts of chlorine and 46 of metallic manga- 
nese. The atomic weight of manganese calculated from these 
data is 30*67, a number which is considerably beyond the 
truth. Dr. Davy prepared the chloride by heating the mu- 
riate in a glass tube communicating with the atmosphere by a 
very small aperture. I have never failed by this method to de- 
compose some of the chloride, a circumstance which complicates 
the analysis, and probably gave rise to Dr. Davy's error. 

According to the analysis of M. Arfwedson (Annals of Phi- 
losophy, N. S. vol. vii. p. 274), the elements of the chloride of 
manganese are in the ratio of 8403 parts of chlorine to 6677 

of 



of the Oxides of Manganese. 27 

of manganese. This result, in the accuracy of which M. Arf- 
wedson does not place implicit confidence, would fix the equi- 
valent of manganese at 28*61. He prepared the chloride by 
placing the carbonate of manganese in a spherical cavity blown 
in a barometer tube, transmitted over it a current of muriatic 
acid gas, and heated the carbonate by means of a spirit-lamp 
as soon as the atmospheric air was expelled from the tube. 
As it is difficult by this, as well as by Dr. Davy's process, to 
procure a perfectly pure chloride of manganese, I had recourse 
to the following method. A solution of the muriate of man- 
ganese was evaporated to dryness, the heat being carefully rer 
gulated so as not to decompose any of the salt, and the dry 
compound was placed in a spherical cavity in the middle of a 
barometer tube about six inches long. Muriatic acid gas was 
then transmitted through the tube, and heat applied by the 
flame of a spirit-lamp. The chloride entered into perfect fu- 
sion at a low red heat, and on cooling yielded a highly cry- 
stalline lamellated mass of a beautiful pink colour. Every 
trace of acid and moisture was expelled by heat ; and while 
the tube was still hot, its extremities were closed by corks, so 
that the chloride might be weighed without attracting mois- 
ture from the air. In the sense above explained it was quite 
neutral. Of this chloride 12*47 grains were dissolved in di- 
stilled water, and formed a colourless solution without any 
residue. The muriatic acid was thrown down by the nitrate 
of silver, and yielded 28*4-2 grains of the fused chloride of sil- 
ver, equivalent to 7*008 grains of chlorine. Consequently the 
chloride of manganese consists of 

Manganese 5*462 28*06 

Chlorine 7*008 36 

It follows from the preceding researches, that 28 is the true 
atomic weight of metallic manganese, and 36 the equivalent of 
that oxide of manganese which forms definite compounds with 
acids, and which I regard as the real protoxide of the metal. 
It is consequently composed of 28 parts of manganese and 
8 parts of oxygen. These numbers agree with the atomic 
weight of manganese as stated by Dr. Thomson, but not with 
that given by Berzelius, who fixes it at 28*463. This estimate 
is made from an analysis of M. Arfwedson, who finds that the 
deutoxide of manganese is composed of 1 00 parts of the metal 
and 42*16 parts of oxygen ; but it will appear from the sequel 
of this paper that the real quantity of oxygen united with 100 
parts of manganese to constitute the deutoxide is 42*857 and 
not 42*16 as Arfwedson supposes. 

On the Protoxide of Manganese. — By this term I mean the 
salifiable base of manganese, the only oxide of the metal which 

E 2 appears 



28 Dr. Turner's Chemical Examination 

appears to me capable of forming regular salts with acids. I 
am of opinion that in this compound manganese is in its lowest 
degree of oxidation. The existence of the sub-oxides de- 
scribed by Berzelius and Dr. John of Berlin, has never been 
satisfactorily demonstrated ; and I have reason to suspect that 
one or other of them would in some of my experiments have 
been generated, did there exist any tendency to their forma- 
tion. 

The protoxide may be formed, as was shown by M. Ber- 
thier.in the 20th volume of the Annales de Chimie et de Phy- 
sique, by exposing the peroxide, deutoxide, or red oxide of 
manganese to the combined agency of charcoal and a white 
heat ; and Dr. Forchhammer has in the Annals of Philosophy 
described an elegant method of preparing it by means of hy- 
drogen gas at a red heat Arfwedson has likewise had recourse 
to this method, and I have employed it very extensively du- 
ring the course of the present investigation. The mode of 
performing the experiment is as follows. The material for 
yielding the protoxide was either the red oxide, deutoxide,"or 
peroxide of manganese : and, occasionally, the carbonate was 
used. When it was wished to employ a red heat only, the 
material was placed in a small tray of platinum foil, which was 
introduced into a tube of green glass, through which the hy- 
drogen gas was transmitted. The heat was applied by means 
of a pan of burning charcoal. To prevent the tube from 
bending while softened by the heat, two or three pieces of 
tobacco-pipe were tied to it longitudinally by means of iron- 
wire. But when it was wished to prepare the oxide at a very 
high temperature, the material was put into a small tube of 
porcelain, and then introduced into a gun-barrel which was 
exposed to a full white heat in a common wind-furnace. A 
supply of hydrogen gas was procured in the usual manner 
from zinc and dilute sulphuric acid; but before coming in 
contact with the oxide of manganese, it was purified by being 
transmitted through a strong solution of potash, and then 
dried by the chloride of calcium. At the close of the process, 
the protoxide was of course preserved in an atmosphere of 
hydrogen gas until it was quite cold. 

The abstraction of oxygen commences at a temperature be- 
low that of redness ; and when the peroxide is employed, it 
becomes red hot by the caloric evolved during the formation 
of water, considerably before the tray which supports it is 
rendered luminous by the heat of the fire. It appears never- 
theless from all my experiments that a strong heat is requisite 
in order to convert all the red oxide into the protoxide. 
When the process is conducted at a low red heat, I uniformly 

found 



of the Oxides of Manganese. 29 

found that on putting the product into dilute sulphuric acid, 
which instantly dissolved all the protoxide, a portion of the 
red oxide came into view. This affords a sure criterion of the 
operation being complete; for the pure protoxide dissolves 
without residue in dilute sulphuric acid, and yields with it a 
perfectly colourless solution. There seems to be no risk of 
decomposing the protoxide by the employment of a high tem- 
perature. I have exposed the recently prepared protoxide a 
second time to the action of hydrogen gas and a long con- 
tinued bright red heat without the weight being changed in 
the slightest degree ; and after exposure to the same gas and 
a full white heat for an hour, it dissolves in dilute sulphuric 
acid without the slightest effervescence. 

The protoxide of manganese is described by Forchhammer 
as being of a beautiful light-green, and by Arfwedson as of a 
pistachio-green colour. I have seen specimens with ' a tint 
very near the pistachio-green, but these always contained an 
admixture of red oxide. The colour of the pure protoxide is 
very near the mountain-green. 

With respect to the action of air, my observations differ 
from those of Forchhammer, who found that recently prepared 
protoxide attracted oxygen from the atmosphere before he 
could weigh it. The protoxide procured in my experiments 
is far more permanent. I exposed fifteen grains of recently 
prepared protoxide to the free action of the air during the 
space of nineteen days, when it was found to have undergone 
no change either in appearance or weight. If, therefore, it 
does attract oxygen at all from the air, the operation must 
proceed very tardily. It absorbs oxygen very slowly even at 
a temperature of 400° F. ; for 7*269 grains of the protoxide, 
after an hour's exposure to that degree of heat, did not gain 
in weight more than 0*021 of a grain. At a temperature of 
600° F. it absorbs oxygen much more rapidly ; and at a low 
red heat it loses its green tint, and becomes almost black in 
an instant. I have repeated this process frequently, but in no 
case did the protoxide take fire, as occurred in the experi- 
ments of Forchhammer and Arfwedson. I entirely agree with 
M. Arfwedson, however, in the statement, that the protoxide 
is converted, by simultaneous exposure to heat and air, into 
the red oxide. This is the uniform result at whatever tem- 
perature the oxidation is effected. 

I have already mentioned my opinion, that, of the oxides of 
manganese, the protoxide is the only one which forms definite 
compounds with acids. It unites readily with this class of 
bodies, without effervescence, producing with them the same 
salt which is formed when the same acids act on the carbonate 

of 



30 Dr. Turner's Chemical Examination 

of manganese. When it conies in contact with concentrated 
sulphuric acid, an intense heat is instantly evolved ; and the 
same phsenomenon is produced, though in a less degree, by 
strong muriatic acid. This oxide is likewise the base of the 
salts which are formed when sulphuric or muriatic acid is 
heated with the peroxide, deutoxide, or red oxide of manga- 
nese. As the accuracy of this statement, as respects sulphuric 
acid, has been denied by an acute chemist and good observer, 
I have been induced to examine the question with considera- 
ble care. I mentioned in my Elements of Chemistry, in ex- 
plaining the process for procuring oxygen gas by means of 
sulphuric acid and the black oxide of manganese, that the 
peroxide loses a whole proportion of oxygen, and is converted 
into the protoxide, which unites with the acid, forming a sul- 
phate of the protoxide of manganese. The gentleman who 
has done me the honour to review that work in the Annals of 
Philosophy, I apprehend Mr. Richard Phillips, has made the 
following remark on the preceding passage. " This statement 
is at variance with both Dr. Thomson's and also with the results 
of our experiments ; for we find that 44 or one atom of peroxide 
of manganese yield 4*2 of oxygen, which is so much nearer 4 
than 8, that there is no question but that the deutoxide, and 
not the protoxide is obtained by the action of sulphuric acid ; 
that this is the case is further proved by the deep red colour 
of the solution of the sulphate, and by its losing that colour, 
as stated by Dr. Thomson, when mixed with sulphurous or 
nitrous acid." 

To decide this point between the reviewer and myself, it is 
only necessary to heat the peroxide of manganese with con- 
centrated sulphuric acid, so as to form a solution highly charged 
with the oxide of manganese, and decant off the solution while 
hot from the undecomposed peroxide. The liquid on cooling 
deposits a perfectly white salt, which possesses every property 
of the protosulphate of manganese. If the acid, which retains 
an amethyst-tint even when cold, be again heated, the red co-* 
lour speedily disappears ; because the red oxide, which is dis- 
solved in small quantity by the sulphuric acid, is then also 
converted into the protoxide with the evolution of oxygen gas. 
The red colour disappears gradually even without the aid of 
heat ; for the solution will be found after a few days to be al- 
most and sometimes quite colourless, while a minute quantity 
of red oxide has subsided to the bottom. On applying a very 
gentle heat, the red oxide is redissolved, and the acid acquires 
a lively amethyst-red colour. It is easy, by operating in this 
way, to obtain satisfactory proof, that a minute portion of red 
oxide suffices to communicate a rich colour to a considerable 

quantity 



of the Oxides of Manganese, 31 

quantity of sulphuric acid. The acid may be made to retain 
its red colour, either by diluting it with water, or by keeping 
it in contact with undissolved oxide. 

On the Red Oxide. — I have followed the usage of most chemists 
in applying the term red oxide to that compound which Arfwed- 
son has described under the name oiOxidum manganoso-man- 
ganicuto (Annals of Philosophy, N. S. vol. vii. p. 267), and which 
is uniformly produced when the nitrate, peroxide, or deut- 
oxide of manganese is exposed to a white heat. In my early 
experiments on this oxide, I entertained considerable doubt 
as to the uniformity of its composition. This opinion origi- 
nated in the remark, that, on exposing the peroxide of man- 
ganese to a white heat, the quantity of oxygen lost by different 
portions of it, though agreeing perfectly in some experiments, 
differed widely in others ; and that, on one occasion, I pro- 
cured the green oxide almost in a state of purity. I subse- 
quently discovered, however, that the disagreement in the re- 
sults was occasioned by the want of a free current of air within 
the furnace. In some of the experiments the draft was un- 
guardedly cut offj and consequently an atmosphere of car- 
bonic oxide gas, collecting around the heated manganese, re- 
duced it more or less nearly to the state of protoxide. On 
avoiding this source of fallacy, the results were no longer dis- 
cordant ; and I am now quite satisfied that the red oxide 
formed at a white heat and with free exposure to atmospheric 
air, is uniform in its composition. The accuracy of this in- 
ference is established by the occurrence of the red oxide in 
nature, as will appear in the sequel of the present communi- 
cation. 

The red oxide, when formed at a white heat and rubbed in 
a mortar to the same degree of fineness, is always of a brownish- 
red colour when cold, and nearly black while warm. The 
powder of the native red oxide has a reddish-brown tint, and 
the colour of the red oxide prepared by exposing the precipi- 
tated protoxide or the carbonate to a moderate red heat, has 
most commonly an admixture of yellow, something like rhu- 
barb, though of a deeper hue ; but both of these acquire the 
red colour when heated to whiteness. 

The red oxide manifests little tendency to pass into a higher 
degree of oxidation by abstracting oxygen from the atmo- 
sphere, even by the aid of heat. Thus a portion of the red 
oxide, preserved for an hour at a low red heat, and freely ex- 
posed to the air at the same time, did not acquire any appre- 
ciable addition to its weight. The protoxide of manganese 
precipitated from the sulphate by an excess of pure potash, 
collected on a filter and washed, fully exposed to the air in its 

moist 



32 Dr. Turner's Chemical Examination 

moist state for twenty-four hours, and then heated in an open 
vessel to a moderate red heat, which was insufficient to de- 
compose the deutoxide, lost only 0*218 per cent by subsequent 
exposure to a white heat. The quantity of deutoxide present, 
therefore, must have been very minute. The anhydrous prot- 
oxide, as already mentioned, always yields the pure red oxide 
when heated to redness in the open air. The carbonate, also, 
in similar circumstances, is converted into a red oxide con- 
taining but a very small proportion of the deutoxide. It will 
appear from these experiments that it is unsafe in analyses to 
heat the precipitated protoxide or carbonate to redness, and 
consider the product as the deutoxide; a practice which is 
calculated to lead analytical chemists into considerable errors, 
and indeed has actually done so. If it is wished to procure 
the deutoxide, the precipitate should be moistened with nitric 
acid, and then exposed to heat. 

I have endeavoured to ascertain the composition of the red 
oxide by several methods. The first is by the combined agency 
of heat and hydrogen gas. In the first experiments 100 parts 
of pure red oxide, in being thus converted into the protoxide, 
lost 6*802 and 6*817 parts of oxygen; but as the resulting 
green oxide, when put into dilute sulphuric acid, w r as found 
to contain a little red oxide, the loss in oxygen must be rather 
below the truth. To avoid this error I exposed 44*256 grains 
of red oxide to hydrogen gas and a white heat for the space 
of one hour, when the loss amounted to 3*153 grains on 7*125 
per cent. 

Judging by the increase in weight which the protoxide ac- 
quires when heated in the open air, 100 parts of the red oxide 
consist of 93*05 parts of protoxide and 6*95 of oxygen. Ac- 
cording to a similar experiment made by Arfwedson, the red 
oxide is composed of 93*153 protoxide and 6*847 parts of 
oxygen. 

In an analysis already described, the carbonate of manga- 
nese was found to contain 56*853 per cent of the protoxide of 
manganese. When 100 parts of the same carbonate are ex- 
posed to air and a white heat, 61*18 parts of red oxide are 
obtained. From these data it may easily be calculated that 
the red oxide consists of 92*927 parts of protoxide, and 7*073 
of oxygen. 

As a mean of the numbers afforded by these three methods, 
it follows that the red oxide is composed of 92*951 parts of the 
green oxide and 7*049 of oxygen, or of 72*291 parts of metallic 
manganese and 27*709 of oxygen. According to M. Berthier*, 

* Ann. de Chimie et de Physique, torn. xx. 

who 



of the Oxides of Manganese, S3 

who reduced the red oxide to the metallic state by means of 
charcoal and a long continued intense heat, the oxygen is only 
26*6 per cent. But this estimate, as M. Berthier himself sus- 
pects, certainly renders the quantity of oxygen too small ; for 
though, guided by theoretical views, I am disposed to consi- 
der my own number not rigidly exact, yet from the care with 
which the experiments were made, I am satisfied their result 
cannot be far from the truth. 

From this proportion of manganese and oxygen, we may 
consider the red oxide a compound either of 80 parts or two 
equivalents of the deutoxide and 36 or one equivalent of the 
protoxide, as M. Arfwedson supposes, or of 44 parts or one 
equivalent of the peroxide and 72 or two equivalents of the 
protoxide of manganese. If, on either of these suppositions, 
the composition of the red oxide in 100 parts be calculated, 
it will be found to consist of 93*104 parts of the protoxide 
and 6*896 of oxygen, or of 72*414 parts of metallic manganese 
and 27*586 of oxygen. These numbers approximate closely 
to those furnished by my experiments, and may serve perhaps 
to correct them. 

The red oxide of manganese, when agitated with strong sul- 
phuric acid, is dissolved in minute quantity, without appreci- 
able disengagement of oxygen gas, and the solution is pro- 
moted by a slight increase of temperature. If the resulting 
liquid be separated from undissolved oxide, and exposed to 
heat, its amethyst-red tint quickly disappears, and the proto- 
sulphate of manganese is generated. When the red oxide is 
briskly heated with sulphuric acid, the protosulphate is form- 
ed, and oxygen gas evolved with effervescence. 

On boiling the red oxide w T ith an excess of very dilute sul- 
phuric acid (in the proportion, for example, of two measured 
drachms of strong acid to five ounces of water), a colourless 
solution of the protosulphate is obtained ; while a portion 
of peroxide is left, the quantity of which corresponds to the 
atomic view just given; that is, 116 parts of the red oxide 
yield 44 parts of the peroxide of manganese. 

When the red oxide is mixed with strong muriatic acid, a 
portion of it is almost instantly dissolved, and communicates 
a deep red colour to the liquid. But the solution is not per- 
manent. The odour of chlorine is perceptible from the be- 
ginning, even at a temperature of zero of Fahrenheit ; the dis- 
engagement of that gas continues slowly, though without di- 
stinct effervescence, until in a few days the solution, if sepa- 
rated from undissolved oxide, becomes quite colourless. The 
red oxide dissolves in hot muriatic acid with effervescence, 
owing to the evolution of chlorine. 

New Series. Vol. 4. No. 19. July 1828. F On 



84 Dr. Turner's Chemical Examination 

On the Deutoxide. — This oxide is prepared by exposing the 
nitrate or peroxide of manganese for a considerable time to a 
rather low red heat. I have found great difficulty in procu- 
ring it artificially in a pure state. After exposing the peroxide 
for an hour or longer to a moderate red heat, the residue fre- 
quently contains too much oxygen for constituting the deut- 
oxide ; and on augmenting the temperature slightly, the loss 
in oxygen is very apt to become excessive. The result is so 
much influenced by slight differences of temperature, that I 
do not feel confident in inferring the existence of the deutoxide 
from such researches. That there is such a compound, how- 
ever, is demonstrated by its occurring in two different states 
in the mineral kingdom. My experiments as to its composi- 
tion, as will afterwards appear, agree with the statement of 
Berzelius, Arfwedson, and Thomson. It is intermediate be- 
tween the protoxide and peroxide, consisting of 28 parts or 
one equivalent of manganese, and 12 parts or one equivalent 
and a half of oxygen ; or rather, to be consistent with the 
atomic theory, of two equivalents of the former to three of the 
latter. Its elements, it is obvious, are in such proportion, that 
it may be regarded as a compound of 44 parts or one equiva- 
lent of the peroxide, and 36 parts or one equivalent of the 
protoxide of manganese ; and into these it may be resolved by 
being boiled in dilute sulphuric acid. 

The colour of the deutoxide of manganese varies with the 
source from which it is derived. That which is procured by 
heat from the native peroxide or the hydrated deutoxide, has 
a brown tint ; but when prepared from the nitrate of manga- 
nese it is almost as black as the peroxide itself, and the native 
deutoxide is of the same colour. 

On heating a mixture of the deutoxide of manganese and 
concentrated sulphuric acid, oxygen gas is evolved with ef- 
fervescence, and the protosulphate is generated. In the cold 
the acid acts upon it slowly, and acquires an amethyst-red co- 
lour ; but this effect does not take place so readily as with the 
red oxide. The solution is attended with the disengagement 
of a little oxygen, a circumstance from which it may be in- 
ferred that a portion of deutoxide is resolved into oxygen and 
the red oxide, and that the latter, on being dissolved, is the 
cause of the red colour. Arfwedson represents the deutoxide 
as yielding a deep grass-green coloured solution with sul- 
phuric acid; but I have never been able to observe this phe- 
nomenon. 

Strong muriatic acid acts upon the deutoxide in the same 
manner as on the red oxide of manganese, excepting that the 
acid acquires the deep red tint more rapidly with the latter 

than 



of the Oxides of Manganese. 35 

than when the former is employed. It is hence probable that 
the red colour is really communicated by the red oxide. 

Peroxide of Manganese. — To procure a pure peroxide of 
manganese, a solution of the protonitrate was evaporated to 
dryness, and the heat continued until the whole of the salt was 
converted into a uniform black mass. It was then reduced to 
fine powder, carefully washed with distilled water, and dried 
by exposure for several hours to a temperature of 600° F. 
On heating a portion of this peroxide to redness in a glass 
tube, a little moisture was expelled, which reddened litmus 
paper powerfully. Consequently the peroxide still retained a 
little nitric or nitrous acid, which I found it impossible to ex- 
pel entirely, except by the employment of a temperature bor- 
dering on a commencing red heat. The peroxide, after ex- 
posure to that degree of heat, was quite free from acid, but 
still retained a trace of moisture. On exposure to a white heat 
it lost only 10*82 per cent of oxygen, whereas had the per- 
oxide been pure, it should have yielded 12*122 per cent. It 
appears therefore that the heat required to expel the last por- 
tions of the nitric acid, decomposes some of the oxide itself; 
and this circumstance induced me not to rely on the analysis 
of the artificial peroxide of manganese. 

From my examination of the native peroxide of manganese, 
I conclude with all other chemists who have of late years 
studied the oxides of manganese, that it contains twice as much 
oxygen as the protoxide. It is accordingly composed of 28 
parts or one equivalent of manganese, and 16 parts or two 
equivalents of oxygen; and in being converted by a white heat 
into the red oxide, it should yield 12*122 per cent of oxygen 
gas. 

Sulphuric acid acts very feebly on the peroxide of man- 
ganese. At first I could observe no action at all ; but on em- 
ploying a considerable quantity of the oxide, and agitating the 
mixture frequently, the acid after an interval of two or three 
days acquired an amethyst-red tint, a minute quantity of 
oxygen gas being at the same time disengaged. The nature 
of the change which is produced when sulphuric acid is heated 
with the peroxide of manganese, has already been discussed. 

Muriatic acid, as is well known, acts upon the peroxide of 
manganese at common temperatures, chlorine gas being dis- 
engaged with effervescence. If heat and an excess of acid be 
employed, a colourless muriate of the protoxide is procured ; 
but in the cold, or if the oxide be in excess, in addition to the 
protomuriate, a deep red coloured solution is formed, similar 
to that already mentioned in the description of the red oxide. 
[To be continued.] 

F 2 VIII. jEr- 



[• 36 <] 

VIII. Experiments on the Pressure of the Sea, at considerable 
Depths. By Jacob Green, M.D. Professor of Chemistry 
in Jefferson Medical College, Philadelphia, United States, 
North America.* 

A MONG the various expedients resorted to for the purpose 
■*** of relieving the tedium and monotony of a sea- voyage, no 
one is more common during a calm, than to attach to a long 
line (the log) an empty bottle, well corked, and then to sink 
it many fathoms in the sea. In all such experiments it is well 
known, that the bottles upon being drawn up are either full 
or are partially filled with water. The manner in which the 
water gets into the bottle is in some instances perfectly obvious, 
but in others very perplexing, if not wholly inexplicable. 
Sometimes the cork, however well secured and sealed, is 
driven into the bottle, and when drawn up the vessel is of 
course found filled with water ; and in such cases, what is a 
little surprising, the cork is often found occupying its ori- 
ginal position in the neck of the vessel, being forced there no 
doubt by the expansion of the dense sea-water on being 
drawn near the surface. This seems to be proved by the 
cork often being in an inverted position. In the above experi- 
ment, and in some others to be mentioned presently, the bot- 
tle appears to be filled instantly ; as the person who lowers 
the bottle down often feels a sudden increase of weight, some- 
what similar to the sensation produced when a fish takes the 
hook on a dipsey line. 

Sometimes the above experiment is varied by filling a ves- 
sel with fresh water, which on examination is found to be 
replaced by salt water; the cork remaining apparently un- 
disturbed. 

Sometimes when the previously empty bottle is only half- 
full of water, this when poured into a tumbler effervesces like 
water highly charged with carbonic acid gas. This is readily 
explained : for when the bottle descends it is full of air, and 
when the water enters, it will of course absorb the air ; espe- 
cially when the dense water itself expands as it is drawn to- 
wards the surface. 

Sometimes the experiment is performed by first corking the 
bottle tight, and then tying over the cork a number of layers 
of linen dipped in a warm mixture of tar and wax ; in fact, 
every device seems to have been tried to prevent the entrance 
pf the water by the cork. In many of these cases, when the 

* Communicated by the Author. 

bottle 



Dr. Green's Experiments on the Pressure of the Sea. 37 

bottle is drawn up from a depth of 200 or 300 fathoms, it is 
found filled or nearly filled with water, the cork sound, and 
in its first situation, and the wax and tar unbroken. Two 
experiments are mentioned, in which vessels with air-tight 
glass stoppers were used. In one case the bottle was broken, 
and in the other some drops of water were found in it. 

How does the water find its way into the bottles ? There 
are two opinions : One is, that it passes through the cork and 
all its coverings, in consequence of the vast pressure of super- 
incumbent water, in the same manner as blocks of wood are 
penetrated by mercury in the pneumatic experiment of the 
mercurial shower. The other and less popular opinion is, 
that the water is forced through the pores of the glass*. 

The following experiment, which I made on the 7th of 
May 1828, in latitude 48+ longitude 24° 34', will perhaps 
throw some light on this subject. — Mr. Charles Dixey, the 
obliging and intelligent master of the packet-ship Algonquin , 
had a boat rowed off from the ship for me, to the distance of 
about half a mile, when the sea was almost perfectly calm. 
A hollow glass globe hermetically sealed, which I had pre- 
viously prepared in Philadelphia, was then fastened to a line, 
and sunk, with a heavy mass of lead, to the depth of 230 fa- 
thoms, or 1380 feet. On the same line, and 30 fathoms above 
the glass globe, was fastened a small bottle with an air-tight glass 
stopper ; 50 fathoms above this, a stout glass bottle with a long 
neck was tied ; a good cork was previously driven into the 
mouth of this bottle, which was then sealed over with pitch, 
and a piece of linen dipped in melted pitch was placed over 
this ; and when cool, another piece of linen treated in the 
same way was fastened over the first. Twenty fathoms above 
this bottle, another was attached to the line, much stouter, 
and corked and sealed like the first, except that it had but 
one covering of pitched sail-cloth. Thirty fathoms above this 
was a small thin bottle filled with fresh water closely corked ; 
and 20 fathoms from this last there was a thin empty bottle 
corked tight and sealed, a. sail-needle being passed through- 
and-through the cork, so as to project on either side of the 
neck. 

Upon drawing in the line, thus furnished with its vessels, 
and which appeared to have sunk in a perpendicular direction, 
the following was the result: 

The empty bottle with the sail-needle through the cork, 

* See Perkins on Pressure, Phil. Mag. vol. lvii. p. 54. J. Deuchar's Re- 
marks on the same, Ibid. vol. Iviii. p. 201. Campbell's Travels, 1st series, 
p. 3.35. Sillhnan's Journal, vol. xiv. p. 194. Deuchar's Mem. in the Trans, 
of the Wernerian Soc. 1821 —-2—3. 

and 



38 Notices respecting New Books, 

and which came up the first, was about half full of water, and 
the cork and sealing as perfect as when it first entered the 
sea. 

The cork of the second bottle, which had been previously 
filled with fresh water, was loosened and a little raised, and 
the water was brackish. 

The third bottle, which was sealed and covered with a single 
piece of sail-cloth, came up empty, and in all respects as it 
descended. 

The fourth bottle, with a long neck, and the cork of which 
was secured with two layers of linen, was crushed to pieces, 
all except that part of the neck round which the line was tied ; 
the neck of the bottle both above and below the place where 
the line was fastened had disappeared, and the intermediate 
portion remained embraced by the line. This I thought a 
little remarkable; and perhaps may be explained by supposing 
that the bottle was first filled by the superincumbent pressure 
with dense sea- water, which expanded on being drawn up 
near the surface. Had the vessel been broken by external 
pressure, that part surrounded with the line ought to have 
been crushed with the rest. 

The fifth bottle, which had been made for the purpose of 
containing French perfumery or aether, and which was there- 
fore furnished with a long close glass stopper, came up about 
one- fourth filled with water. 

The hollow glass globe, hermetically sealed, which was 
the last and had been sunk the deepest of all, was found per- 
fectly empty, not having suffered the smallest change. It is 
therefore concluded, that at the depth of 230 fathoms the wa- 
ter enters glass vessels through the stoppers and coverings 
which surround them, and not through the pores of the glass. 
What the effect of a pressure of 400 fathoms or more will 
have on the glass globe above mentioned, Captain Dixey has 
engaged to ascertain for me on his return to America, if op- 
portunity shall offer. 



IX. Notices respecting New Books. 

A Geological Memoir on a Part of Western Sussex; ivith some Ob- 
servations upon Chalk-Basins, the Weald- Denudation, and Out- 
tiers- by -protrusion. By P. I. Martin. London, 1828; 4to; 
pp. 100, and Synoptical Table; coloured Plates iii, and a Geo- 
logical Map. 
ON the occasion of reviewing Mr.Mantell's admirable " Illustra- 
tions of the Geology of Sussex," in the Philosophical Maga- 
zine for December last, we expressed a hope that the example of 

that 



Martin's Geological Memoir on Western Sussex, 39 

that gentleman, in carefully and minutely examining the strata and 
organic remains occurring in his own vicinity in Sussex, would be 
extensively and zealously followed, and that every important assem- 
blage of strata in our island, might have its respective local inquirer. 
Since the publication of that review, the same means of augment- 
ing our knowledge of the mineral structure of our country, and of 
promoting the advancement of geology in general, have been ur- 
gently recommended from the Chair of the Geological Society ; in 
an Anniversary Address, as replete with comprehensive and correct 
ideas on the present state and requirements of the science, as it is 
with attempered views of geological theory, and the good-feeling 
to which the social pursuit of useful knowledge can never fail to 
give rise*. But we did not expect so soon to have the pleasure of 
directing our readers' attention to another highly interesting work 
of local geology, frorii which it appears, that, in one instance at least, 
our hopes of the benefits that might accrue from the plan of in- 
quiry we ventured to suggest, have been fully justified. We ob- 
served, on the occasion alluded-to, that the "local inquirer," "bring- 
ing the general ascertained facts of the science to bear upon the 
peculiar phenomena of his own district, might obtain results reci- 
procally illustrating those general facts, with the same success that 
has attended the active labours of Mr. Mantell." Now this has 
been precisely the case with the researches of Mr. Martin, detailed 
in the work before us. For, having applied his general knowledge 
of the structure of the earth to the particular examination of a por- 
tion of the " Weald-denudation," he has become acquainted with 
facts, to a certain extent peculiarly observable in this district, which 
have led him to a theory — not, be it observed, an hypothesis,— o£ 
derangement and denudation, and of the origin of Chalk -basins, 
which will probably contribute materially to alter the views hitherto 
prevalent among geologists, of the history of the superior and 
supermedial strata in general. Nor is this result the less va- 
luable, because ideas of a similar theory had been previously pro- 
mulgated, without the author's knowledge, by two such accurate 
observers as Mr. Poulett Scrope and Professor Buckland. And 
there is yet another point of view in which the present Memoir be- 
comes interesting ; for since the research which led to its composi- 
tion was made many months before either the delivery of Dr. Fit- 
ton's address to the Geological Society referred to above, or the 
publication of our own review of Mr. Mantell's " Illustrations," we 
may regard it as a proof that the importance of specific local in- 
vestigations has already been appreciated and acted upon by geo- 
logists j and that we may confidently expect, at no distant period, 
memoirs of equal utility on other districts and formations. 

Mr. Martin, willing, we apprehend, to enlist all classes of intel- 
lectual inquirers into the service of geology, prefaces his Memoir 
with an " Advertisement to the general reader." In this he briefly 
describes the Weald-denudation, illustrating his account by a profile 
of that remarkable tract, and also adverts to the interest of the 

* See Phil. Mag. and Annals, N. S. vol. iii. p. 299. 

stupendous 



40 Notices respecting New Books. 

stupendous convulsions which must have been concerned in produ- 
cing the phenomena it exhibits ; quoting in conclusion the subjoined 
apposite observations by the Father of inductive science : " Men 
use commonly to take a prospect of nature, as from a high turret ; 
and to view her afar off; and are too much taken up with generali- 
ties. Whereas, if they would resolve to descend and approach 
nearer to particulars, and more exactly and considerately look into 
things themselves, there might be made a more true and profitable 
discovery and comprehension." 

The Advertisement is succeeded by fourteen pages of " Introduc- 
tory Remarks." It is here stated that the substance of the follow- 
ing Memoir was read before the Geological Society in March 1827; 
( See Proceedings of the Geological Society, No. 2 ; or Phil. Mag. 
N. S. vol. i. p. 388.) and that it then attracted some attention, 
among other causes, from its bringing again into discussion the ar- 
rangement and nomenclature of the beds immediately below the 
chalk. This subject is succinctly discussed in these Remarks, and, 
as it appears to us, in a luminous and satisfactory manner ; the 
•* upper shale" of the " Survey of the Yorkshire Coast" being re- 
garded as identical with gault ; and the whole suite of sands and 
clays between the chalk and the Weald-sands, &c. grouped to- 
gether, in accordance with the observations of Messrs. Sedgwick and 
De la Beche, under the appellation of glauconite. For the upper 
member of this series, embracing every bed between the chalk 
and the gault, the name of malm is substituted, in place of the 
terms Jirestone and upper green -sand, successively employed by 
Dr. Fitton, and malm-rock, adopted by Mr. Murchison*. 

The weald-clay and the iron- or Hastings-sand are regarded as 
deposits of common character and single origin, — as constituting one 
formation ; and since Hastings-sand or iron-sand would be as little 
designative of the whole thing signified as Weald-clay, and to avoid 
the inconvenience of the periphrasis of Weald-sands and-clays, Mr. 
Martin proposes, as any coihpound from Weald must have a Saxon 
termination, to call the whole formation the Wealden. In the choice 

of 

* We are not aware that either of the designations here proposed can be 
objected to; but at the same time we are unwilling to relinquish the term 
firestone ; for, although it be very true, as Mr. Martin observes, that " any 
stone of a particular combination of lime, argil, and silex, may be a firestone,'* 
(i. e. a stone that will sustain a high temperature without alteration, and may 
thence be applied to such purposes in the arts as require a stone of this 
quality,) yet the term having been exclusively applied by English geo- 
logists to a species of stone occurring in the upper member of the glauco- 
nitic series, and derivatively to this subordinate formation itself, whatever its 
mineral nature, is not liable to misconstruction ; and some circumstances in 
its history which Mr. M. has not alluded-to, render us very desirous that its 
use should be retained by geologists. The beds of this substance in the 
neighbourhood of Godstone, in Surrey, and other localities, were extensively 
quarried by our ancestors, for the erection of many of their ecclesiastical 
and other edifices, as well as for the purposes of sculpture; examples of 
which may be seen in parts of Westminster Abbey, in the repaired south- 
east angle of the keep of Rochester Castle, &c. : and thence the name, as 

applied 



Martin's Geological Memoir on Western Sussex, 41 

of this appellation, he observes, he has been " guided by a wish to 
do as little violence as possible to inveterate habit, as well as 
to adhere to the useful practice of deriving it from the locality in 
which the type is best exemplified." 

The Introduction concludes with some remarks on the nature 
and difficulties of the research which led to the composition of the 
Memoir, and on the theory of the Weald which that research in- 
duced the author to form. It is here stated that down to the time 
of the memoir's being read before the Geological Society, " the 
writer was entirely unacquainted with the existence of any attempt 
to explain the act of denudation by any other agency than that of 
watery flood." His own speculations upon the structure of the 
country " had produced a conviction of some other agency be- 
sides that of water having been called into action, and that that 
agency had at the same moment of convulsion formed what are 
called the Chalk-basins of London and Hampshire, and in that act 
broken up what is now the cavity of the Weald." By an extension 
of his reading, however, he has found that Mr. Scrope, in his work 
on Volcanoes, published in 1825, promulgated a sketch of this theory 
of the Weald; and that, at about the same time, Prof. Buckland, in 
a paper read before the Geological Society in 1825, and published 
in the following year, gave a conjectural explanation of the same 
kind. If by these circumstances, Mr. Martin observes, " he has 
been deprived of the satisfaction of believing himself the first to 
promulgate this discovery, he has the pleasure of finding his opi- 
nions backed by high authority ; and is emboldened to carry on the 
research to a satisfactory exposition of many of the facts which 
bear upon this theory, and are strong presumption, if they do not 
amount to a perfect proof, of its truth." 

The Introduction is succeeded by the " District Survey," illus- 
trated by a map extracted from the Ordnance Survey, coloured 
geologically, and comprising that part of Sussex which extends 
from the Adur, between Steyning and West Grinstead, on the east ; 
and the little stream (called for convenience the Lod,) which runs 
into the Rother by Lodsworth and Half-way-bridge, between the 
chalk-downs at Graff ham and the foot of Blackdown, on the west. 
The chalk, malm, gait, Shanklin-sands, wealden, diluvium and al- 
luvium of this district, are successively described, more or less at 
length, according to the novelty of the information to be imparted ; 
but in all cases the descriptions are illustrated by tables of the 

applied to this. stone, has become familiar to antiquarian and topographical 
writers on the South of England in general, and also to architects. Thus 
this stone is emphatically denominated "Firestone" by Sir Christopher 
Wren, as may be seen in the * Parentalia? We allude to these circum- 
stances the more readily, as we perceive, from various remarks in his Me- 
moir, that Mr. Martin is fully aware of the importance to the increase and 
unity of knowledge, of preserving in scientific disquisitions those popular 
appellations which have been from time immemorial bestowed on the ob- 
jects of research j and of adopting in science the few well-understood deno- 
minations of the arts. 

New Series. Vol. 4. No. 19. July 1828. G mineral 



42 Notices respecting New Books. 

mineral and organic contents of each formation respectively. The 
two groups of the Shanklin-sands are described in a very discrimina- 
tive and particular manner ; and an extract of a letter from Dr. 
Fitton is annexed, stating his confirmed opinion that the tract of 
country in Sussex, consisting of these sands, is geologically identical 
with that of the vicinity of Folkstone in Kent. 

The " Wealden " includes " the Weald-clay, Hastings-sand, iron- 
sand, and Tilgate-beds of various geological writers." 

In this section of the work, after describing the transition from 
the green-sand to the weald-clay, and stating that the escarpment 
of the former is every where prolonged by a considerable slope of 
the adjacent clay, Mr. Martin describes the beds assimilating to the 
Hastings-sand, which he has discovered in the Weald, in the fol- 
lowing terms : 

" Besides this slope, there is from the bottom of the green-sand a 
breadth of from a quarter to half a mile of clay, giving together an 
average depth, perhaps of 150 or 200 feet. At a moderate depth 
from the surface, this clay is generally blue, running into layers of 
hard blue shale, often impressed with theCypris faba; and contain- 
ing nodular concretions in concentric layers of ferruginous clay, 
sometimes containing calcareous matter. These argillo-calcareous 
Septaria are sometimes coated with a ferruginous concrete, con- 
taining casts of shells of the genera Cyclas, Cyrena, and Paludina, 
with the Cypris faba. At the top of this stratum, also, at its junc- 
tion with the green-sand, in one locality, the author has discovered 
large bones of vertebrated animals* inclosed in a ferruginous con- 
crete of sand and clay, but too imperfect to be appropriated. 

" At the bottom of this first layer of the weald-clay, appears the 
first bed of sand, of which the thickness is uncertain. Sections have 
been made in it to the depth of twenty or thirty feet, and it is pro- 
bably as much more. It is a brownish-yellow micaceous sand, 
abounding in white argillaceous veins, and with a coarse iron-rag f, 
sometimes containing casts of Cyclades, the teeth and scales of 
fishes, and vegetable impressions J, and in every respect assimila- 
ting to what has been hitherto considered the true Hastings-sand. 
The course of this bed of sand has been particularly attended to, 
and it has been traced through all the line of country here attempted 
to be described. From Mulsey (in the line of section of the Arun- 
del and Bognor road), tracing it westward, it may be found at 

* «* At Henfield between the village and the turnpike-gate, on the Hors- 
ham road, associated with Vivipara." 

f " The sand is sometimes sufficiently indurated to form a building stone. 
And the iron-rag frequently becomes a conglomerate of sand and clay, with 
angular, and sometimes slightly rolled fragments of chert and sandstone. 
It has been extensively quarried in this part of the" country, anciently, for 
smelting." 

J " A specimen of Endogenites erosa from this course of sand, was found 
near Mulsey, and is now in the possession of Mr. Sowerby. It measures 
about ten inches in length, and six in circumference, and has lost a few 
inches at its apex. At the base, it is broader than that figured in Mantell's 
Tilgate Forest. The petrifying matter is silex." 

Bignor 



Martin's Geological Memoir on Western Sussex, 43 

Bignor-farm, under Bedham Hill, Buckfold, Parkhurst, Lickfold, 
and within half a mile of Blackdown, near Lurgershall, where there 
is a fine bank of it exposed at Northhurst-farm. Eastward it runs 
by Willets and Spear Hill, and crosses the Worthing road, at Win- 
caves ; from whence its course is a good deal disturbed by the 
disruption of the Vale of Greenhurst ; but it is found at Jessups, and 
again a little north of Henfield*." 

The first course of the well-known concrete of fossil shells of He- 
lix or Vivipara, called Sussex marble, is followed by another suc- 
cession of clays, of much less depth than either of the former ; and to 
this follows a second bed of sand more micaceous and of a deeper 
brown, with less admixture of clay, and carrying Horsham grit. 
Next succeeds the thickest and finest bed of Sussex marble : there 
are then beds of blue and red clay, and a third course of fawn- 
coloured micaceous sand. 

" Immediately below this course of sand, a thick bed of red clay 
succeeds, and then the calcareous grit, sand-stone, and clays of 
what has generally been considered the * forest range' of the weald. 

" By this sketch of the contents of this part of the weald, it will 
be seen that there are two distinct beds of sand above the Sussex 
marble, the highest of which has all the character of the * Hastings- 
sand,' and the second carries Horsham grit. 

" There is therefore no line of demarcation to distinguish the 
weald from the Hastings-sands and -clays, except a slight elevation 
of the line of country, a more stony structure, and greater sterility." 

To the " District Survey" succeeds the " Theory of Derangement 
and Denudation," which is certainly the most important part of the 
work. But we find it difficult to convey an adequate idea of this 
theory by extracts. Those which we subjoin, however, will impart 
some idea of it. 

After stating that the Weald-denudation is understood to be 
bounded on each side by what are called the chalk-basins of Lon- 
don and Hampshire, the author observes, that, although the con- 
tents of these basins have been carefully examined and described, 
no satisfactory explanation of the mechanism or mode of formation 
of the basins themselves has yet been given. — He then proceeds to 
give his own theory, and partly in the following manner: 

" The strata which compose these basins, then, previously in a hori- 
zontal position, suffered disruption; and in the act qfbasining (whether 
by the elevation of the sides, or the subsidence of the central parts, is 
not now material), all their parts were deeply and extensively fissured, 
in an order correspondent with that act; — producing, with the help of 
diluvian action, a system of longitudinal and transverse valleys answer- 
ing to the double inclination (the dip and lateral bearings, or obliquity 
of the plane) of their fractured masses, and a consequent removal of 
the broken materials brought within the range of the denuding force. 

" The effect of raising from the horizontal position, or in any other 

* " The irregularity of the denudation between Warminghurst and Hen- 
field, seems to have left outliers of this sand, as well as of the upper bed of 
weald-clay, out of the usual course in that line of country." 

G2 way 



44 Notices respecting New Booh. 

way stretching, a ponderous and frangible body, is to produce 
a division of its parts in such order and direction as its varying 
strength and tenacity dictates; the fractured parts taking their 
places, according to their magnitude or gravity, or the disposition 
of those which support them. This irregular fracture, alternate ele- 
vation and subsidence, and settling of parts thus disturbed, are well 
exemplified in the familiar operation of the heaving of the spade in 
digging. If the earth be tenacious and the action steady, it tears 
with such a divergence of the principal rents as will be here de- 
scribed ; and the more friable parts are seen dropping in in such 
a way, and in such proportion, as the moving power dictates, and 
their structure allows. If another illustration were necessary, it 
might be found in what we observe in the elevation and cracking of 
the flour which covers the fermenting nucleus in a baker's trough. 

" Where opportunities occur for tracing these appearances in the 
weald, they are found to be in perfect accordance with this theory. 
These opportunities present themselves frequently in the clay 
districts; but they are more distinctly traceable in the stony, in the 
dip and variable lateral bearings of the several masses. It may 
be safely said, that undulation, at the time of deposit, had very lit- 
tle share in these phaenomena, or in the construction of the hills 
and valleys of these districts. Every variation in dip or lateral 
bearing has its commencement in a fracture, or if the displacement 
be moderate, such a contortion as would be produced by the gra- 
vitation of bodies like these, moving under great superincumbent 
and lateral pressure. 

" The general dip of the chalk-hills is southward, but the lateral 
bearings of the several masses are variable*, and the inclination 
also different in different localities. Next to these succeed the more 
broken strata of the green-sand ; and lastly, the smaller lacerations 
of the wealden formation, the widely spreading transverse fissures 
of which concur to produce the effect of longitudinal ones over all 
the convexity of the ' forest ridge.' But it is not to be under- 
stood, that there is any difference in the general disposition of all 
these parts. The convexity extends from the bottom of the Eng- 
lish Channel to the bottom of what is called the London basin. 
This convexity may be likened to a dome, and the loss of a part of 
the crown of the dome is the weald vacuity. In other words, the 
commencement of each basin is in the anticlinal line of the weald 
valley. From this point, all the strata begin to slope. Both basins, 
therefore, may be said to be entire in a part of the wealden, al- 
though they have lost a part of their rims in the chalk and the 
glauconite. 

* " In ordinary geological language, there is not sufficient precision used 
in these terms ; and lateral bearings are confounded with the dip, which 
should express the backward and downward inclination only. Thus, of the 
strata in question, sometimes we are told that they dip S.E., sometimes 
S.W. The fact is, that they all dip to the south, generally speaking, but 
the obliquity of the plane, or lateral bearing of the different masses, is some- 
times east and sometimes west." 

" The 



Martin's Geological Memoir on Western Sussex, 45 



^ 



" The principal transverse fissures, some of which were destined to 
become river-channels, have a remarkable correspondence on each 
side of the valley, particularly in the chalk, and in several instances 
are directly opposed to each other ; which could not have happened 
without a simultaneous action and common consent and continuity 
of parts. The direction of a rent would be ruled by the density and 
tenacity of the different parts of the stratum ; occasionally deviating 
from the straight line, it might be lost in one part, and taken up 
and carried on by another, giving less resistance. The coincidence 
is therefore the more remarkable, and proves not only the continuity 
of the chalk strata at the moment of convulsion, but also their uni- 
form density and strength. Of the valleys thus opposed to each 
other by the continuity of the greater transverse fissures, the most 
remarkable are, — the defiles of the Arun in the South, and the Wey 
in the North Downs ; the vale of Leatherhead, or the Mole, and 
that of Findon, or the Worthing road ; of the Adur and Smitham- 
bottom, or the pass of Merstham and Croydon. The Ouse is also 
opposed to the Darent, and the Cuckmere to the Medway. 

" But it must not be supposed that this simple transverse fissure is 
the only appearance of displacement exhibited by the chalk strata. 
They have suffered in common with the other rocky strata, that 
adjustment of parts which might be expected from the nature of the 
material on which they rest. If the fissile character of the stony 
strata determine their division in straight and broad lines, it would 
also be the character of the wealden formation to be torn and con- 
torted in a manner widely different. For a stratum of clay of great 
thickness, carrying stone barely sufficient to give it stability, would 
tear rather than split in the act of displacement; and such a diver- 
gence of the fissures as might be expected in so tenacious a mass, 
can be readily traced in every part of the weald surface. This di- 
vergence and laceration has therefore modified the disposition of 
the stony strata still superincumbent upon the clay ; and the subsi- 
dence, elevation, and contortion consequent thereon, are every- 
where visible in the dip and variable bearings of all their masses. 
In appreciating the evidence of these acts of laceration and fracture, 
it must not be forgotten also, that strata of various structure far 
below these under review, have suffered the same disruption; and 
by the variable nature of their fracturings have operated to modify, 
and in some cases to obscure, a great part of the direct testimony 
of the order here described. The pressure of superincumbent strata 
of unknown thickness and kind must also be taken into account; 
and it will not be thought wonderful that, diluvian action and the 
operation of more modern causes apart, there should be so little 
direct evidence of fissure upon the surface. 

"The divergence or distribution of the transverse fissures is to be 
traced in the upper stony strata, as well as in the minuter divisions 
of the clay districts. If a fissure of this sort be followed from its 
termination in any of the hilly counties, it will be found to present, 
first a little coomb, into which the stone inclines on both sides, and 
at first carrying no water. By-and-bye springs burst forth, (the 

natural 



46 Notices respecting New Books. 

natural consequence of this convergence of layers of stone,) and 
it becomes a valley with a rivulet ; both the valley and the rivulet 
enlarge by the accession of other coombs and rivulets, the effects of 
the branches of one greater river fissure ; and the eye of the observer 
may, from any considerable eminence, embrace the courses of these 
valleys, as they converge towards some of the river outlets*." 

The theory is satisfactorily illustrated from the phenomena ob- 
servable in the valley of the river Arun, and in the vale of Green- 
hurst. A few pages of concluding observations present some acute 
criticism on the reasoning of the French naturalists on the sera of 
the formation of chalk-basins, &c. : and here occurs a remark on the 
geological site of the Thames Tunnel, which, as this analysis has oc- 
cupied more space than was originally intended, we shall offer a 
reply to in our next Number. 

The last section of the memoir, " On Outliers-by-protrusion," we 
give entire; and also, as a summary of the facts relating to the geo- 
logical structure of the weald, we copy Mr. Martin's Synoptical 
Table. — Our opinion of the merits of the work is sufficiently evinced 
by our remarks in the commencement of this article, and the full 
account we have given of its contents, without the necessity of ex- 
patiating further on the subject. 

" On Outliers by Protrusion. — In reviewing the outskirts of the 
district made the object of the ' Survey ' of the foregoing Essay, 
the writer's notice was drawn to a remarkable chalk-eminence 
upon the coast, between Worthing and Little Hampton, called 
High-Doxvn. 

" High-Down stands considerably in advance of the general line 
of chalk-hills, and is insulated by a breadth, between them, of two 
miles of plastic clay, covered by the woods of Patching, Clapham, 
and Castle-Goring. It has, therefore, the character of an outlier ; 
and upon a closer inspection, was found to present an escarpment 
to the sea, from which it is about two miles distant, and to have a 
northerly dip, — in opposition to the general inclination of the South 
Downs. The observation of this phenomenon immediately sug- 
gested the thought, that the well-known outlier of Ports-Down, in 
Hampshire, would be found to be in the same predicament. And 
as there is nothing to be observed of High-Down, which will not 
apply to the larger outlier above-mentioned, a description of the 
latter will suffice f . 

" Ports-Down is a long narrow ridge of chalk, running east and 
west, which, rising three or four hundred feet above the level of the 
sea, overlooks the Island of Portsea, and the several islets and in- 

* " It will not be supposed that the author means that this should apply 
to the courses of all rivers, and in all their parts. He is now talking of the 
Arun and the Adur, and not of the greater rivers of the globe. But the 
principle is capable of extension to the tributary streams of these also ; and 
all perennial rivers must have their sources in disruption, — for disruption 
and displacement are the essence of springs and fountains." 

f " The reader may take the Ordnance Survey, or any other good map 
which marks the high grounds, for a guide." 

lets 



Martin's Geological Memoir on Western Sussex. 47 

lets of its celebrated harbour. To these, and to the south, it pre- 
sents an abrupt escarpment ; on the other side, it slopes rapidly 
northward, and is quickly lost, under the plastic clay and sands of 
the * Forest of Bere ;' of which there is about five or six miles, be- 
tween it and the main body of the chalk of the South Downs, with 
which it forms a trough or basin. In advance, and at more than 
double the distance, are the chalk-hills of the Isle of Wight. It 
therefore distinctly belongs to, and is an emanation from, the north 
side of the Hampshire basin. 

" At the eastern extremity, the chalk rises out of the plastic clay 
at Bedharapton, and, taking a direct course westerly, gradually at- 
tains its greatest elevation between Cosham and Portchester; it 
then gradually declines, and, after a course of about seven miles, 
sinks again under the plastic clay, at Fareham. Here it ceases to 
be an outlier, but the line of elevation can be traced further west- 
ward, and the chalk is sometimes quarried through the overlying 
strata, beyond Fareham, and comes to the surface again, at Titch- 
field and Funtley ; beyond which, this research has not been car- 
ried. 

" At the eastern extremity of the ridge, where it emerges, at Bed- 
hampton, it dips gently northward, with a lateral bearing to the 
east. In the centre the inclination is much greater. There is no 
good section where it appears to be the greatest, but where the 
hill is intersected by the Portsmouth road, it amounts to twenty- 
five or thirty degrees, and at the highest, is perhaps nearly forty. 
Westward from thence, it is again diminished, and in the chalk-pits 
near Fareham, is found not only to have lost all its northward dip, 
but also to have returned to the general southward declination of 
the Hampshire Downs, dipping five degrees in that direction, with 
a lateral bearing westward. In inclination, therefore, it traverses 
an arc of forty -five degrees, in the space of about four miles. To 
answer to this contortion, a course of fissures may be traced, and 
these are particularly well displayed in the chalk-pit, close to Fare- 
ham, where, as the outlier sinks under the plastic clay, they have 
not been exposed to obliteration by denuding causes. Through a 
gap begun by some of these fissures, or a larger disruption of the 
whole mass, the rivulet passes, which takes its course transversely 
to the chalk, into the Fareham inlet ; for west of it, the general 
bearing of the ground, by Upland-House, and on towards Funtley, 
is indicative of a resumption of the northerly dip. 

" A moment's consideration will show, that such an outlier as this 
is very differently circumstanced from the more common one, or 
that which is entirely detached from the main body ; separated by 
the removal of the intervening parts, and therefore properly the 
outlier of erosion. This, although it is an outlier in reference to the 
surrounding parts upon the surface, is still connected with, or in- 
cumbent upon, or in juxtaposition with, the kindred stratum below; 
and may therefore be called an outlier by-protrusion. 

[Concluded on p. 50.] 

SYNOP- 



48 



Notices respecting New Books, 



• 


r 

M 

< 

z 

- 


3 
O 

Q 

-3 

3 
O 
CO 


Sutton, Bury, Amberley, Washington, Steyning 
—the high grounds immediately under the 
chalk-hills. 


Bottom of Sutton and Bury hollow-ways, 
Washington, Rowdell, Fulking, &c. 

Bignor Park, Bury Common, New Woods, 
Hardham. 

Wiggonholt*. 


Burton, Redhill near Bignor, Sandgate, Sul- 
lington, Pulborough, Fittleworth, Henfield. 

Graffham Common, Cold-Waltham, West- 
Chiltington Common, Sullington, Wiston- 
Parsonage, &c. 

Parham, Sparright Lodge, Pulborough, West 
Chiltington Common. 


West-Chiltington, Thakeham, Henfield, Ash- 

urst, Pulborough, Bognor (in Fittleworth 

parish), Tillington, &c. 

Pulborough Quarries, Pitt's Hill, Bognor Quar- 

Bedham Hill, Brinkshole, Petworth. [ries, &c. 


•J 

< 

< 

O 

H 
O 
>< 


CD 

tf 
W 
H 

Dd 
O 

< 

PS 

5 

H 


8 

S"53 
+* — 
3 3 

coK 


Blue-chalk-marl above, graduating into indurated, 
argillaceous limestone, or malm-rock ; with sub- 
ordinate beds of green-sand. 

Containing Ammonites, Pectines, Tnocerami, &c. 

Soil, moist and fertile. 


Upper part, — harsh and shaley brown clay, mottled 

blueish ; — 
Lower beds, — blue and black shale, and stiff clay; 

sometimes containing ferruginous concrete; — 


Ammonites, — other fossils said to have been found 

in wells. 
Soil, good for pasture ground, and for the growth 

of oak and elm. 


Coarse red-sand, with layers of ironstone, compact 

and cellular. 
White, yellow, brown, and black sand with quartz 

grains, and occasionally green particles ; — with 
Veins of ochreous clay, and subordinate beds of 

black shale and clay. 

Terebratulae and other fossils abundant at 

Soil, for the most part arid and barren. 


Sand, full of green particles,alternating with courses 
and large concretional masses of blue calcareous 
Green sand-rock or Pulborough stone. [s rit - 
The same, siliceous, and passing into chert. 
Containing Ammonites, Pectines, Myae, Pholado- 

[mya?, &c, 
Soil, moist and fertile. 




00 

o 

9 
> 

CO 


3=' 3* 
« C5 
-CJ3 

oo 

•- - 

0) ID 

a.o 


1 Malm. 

2 Gait. 

Ferruginous J 
Sand. \ 

3 Shanklin Sands. 

Lower J 
Green-sand. 


1 


O 
H 

s 

i 
o 


M 

3 

>< 
■ 

< 


w 

H 
O 

< 





ft 

1 

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fcO 



Martin's Geological Memoir on Western Sussex. 



49 




New Series. Vol.4. No. 19. My 1828 



H 



"The 



50 Notices respecting Neiv Books. 

" The relations of the two specimens of Ports-Down and High- 
Down are exceedingly simple, and their history extremely well dis- 
played. The opposing dip, contortion, and form of both eminences, 
are satisfactory proof of their protrusion from the parent stratum 
below ; — whether effected by a separate and distinct propelling im- 
pulse, or simply by arrest, by the interposition of some opposing sub- 
stance, during the subsidence of the main body, it is not now material 
to inquire. The mass thus detached and elevated, a part of which 
forms Ports-Down, must have been covered, as some portion of it 
still is, by the overlying strata, and is an outlier only where its 
highest parts have been exposed to the denuding forces. 

** No line of country exists, indicative of any connexion between 
Ports-Down and High-Down, which are twenty-four miles asunder. 

" It belongs to the general history of chalk-basins, and would 
pass the limits prescribed to this research, to endeavour to show 
which of the actions above referred to, have produced these out- 
liers. Either way, they tend powerfully to illustrate the theoreti- 
cal parts of the foregoing Essay, and to prove the disruption and 
displacement of the chalk, — the act of basining, — posterior to the 
deposit of the higher strata. 

" The Isle of Thanet is probably an outlier of this description, and 
the writer is informed that Windsor stands upon chalk, which must 
therefore be also an outlier-by-protrusion, and perhaps so also the 
chalk islands in the Paris basin. 

" It will be easily seen, that it is not necessary that such outliers 
should have a dip and an inclination opposite to the main body. 
In the elevation of the former, or the subsidence of the latter, they 
may both preserve the same parallelism, or nearly similar relations 
to the horizontal line. It is enough, if it be proved, that they are 
out of the direct line with each other below ; and that the detached 
portions have been exposed to the flood of denudation upon the 
surface, and are outliers where they have been elevated within the 
range of the denuding force." [ B. ] 

Elements of Chemistry. By Andrew Fyfe, M D. F.R.S.E. &c. 1827. 

In the Philosophical Magazine for November last we offered some 
observations on Dr. Fyfe's f* Manual of Chemistry," without any an- 
ticipation that it would so soon fall to our lot to notice two octavo 
volumes on the same subject by the same author. We presume that 
the success which has attended Dr. Fyfe's first work, has stimulated 
him to fresh exertion ; and we have with no slight attention examined 
nearly the whole of the work now under consideration, in the hope 
of being able to give a more favourable opinion of it, than that to 
which we conceived the Manual was entitled. 

We shall not occupy either our own time or that of the reader with 
a minute examination of the arrangement adopted in the present 
work : it is materially altered from that of the Manual 5 and we do not 
perceive that the change is accompanied with the improvement, for 
which there was so ample room. The Elements commence with the 
subject of Heat, while in the Manual, and in our opinion with better 

judgement, 



Dr. Fyfe's Elements of Chemistry. 51 

judgement, Attraction was first treated of. Dr. Fyfe prefers the term 
caloric to that of heat, observing that " by heat we are to understand 
the sensation produced by a warm body j by caloric, the active cause 
of this sensation." Having made this distinction between cause and 
effect, our author proceeds to state, that " different bodies have dif- 
ferent quantities [of caloric], and on this depends their temperature.' 
This is an error of very considerable importance 5 and if one mistake 
could be compensated for by another, Dr. F. has done all that can be 
required of him, by asserting that " our sensations give us no indica- 
tion whatever" of temperature j ergo, our sensations indicate no dif- 
ference between a cold bath and a warm one. 

When treating of Pyrometers, Dr. F. has given a description of 
Wedgwood's instrument, and on many occasions he refers to it as a 
standard for determining the fusing-point of bodies ; and yet he ad- 
mits the fact, ascertained we believe by Sir James Hall, that this py- 
rometer is liable to one great objection, viz. that " if the clay be ex- 
posed to a moderate heat for a long time, it will contract nearly as 
much as if heated intensely." Being aware of this circumstance, all 
notice of the instrument ought surely to have been omitted, for it is 
worse than useless to quote that as authority which we do not believe 
to be true. 

Under the head of Cohesive Attraction, some attention is naturally 
bestowed by our author upon the subject of Crystallization. But the 
little which he has said respecting it is so inaccurate and incomplete, 
that it would have been better altogether omitted. No mention 
whatever is made of a goniometer of any sort 5 and in treating of 
Salts in the various parts of the work, their crystalline forms are very 
erroneously described. Thus with respect to carbonate of soda, it is 
stated that it crystallizes in octohedrons composed of two four-sided 
pyramids joined by their bases j and Alum is correctly described as 
possessing the octohedral form. We may therefore conclude that in 
Dr. Fyfe's opinion there is no difference between the crystals of these 
very different salts. The fact however is, that, although the apparent 
form of carbonate of soda is an octohedron, yet it has a rhombic base 
and it is elongated, whereas the octohedron of alum is a regular one. 
We have said the apparent form is that of an octohedron, but this is 
not the real form of the crystal ; Mr. Brooke has shown that it is an 
oblique rhombic prism. Various other salts are very incorrectly de- 
scribed, but we have not room for further observations on this subject. 

We are told by Dr. Fyfe, when treating of Acidifying and Alkalify- 
ing principles, that the merit of the discovery of oxygen is due to 
Priestley, Lavoisier, andScheele, the priority of it, only, being assigned 
to Priestley. It is however quite clear from Dr. Priestley's statement, 
(Doctrine of Phlogiston Established, p. 88. 1800.) that Lavoisier 
knew nothing whatever of the existence of oxygen, until Dr. Priestley 
mentioned it to him during a visit to Paris. On this subject there is 
also another error, which we should not have expected in the work of 
a medico-chemical writer. Dr. Fyfe says that Dr. Priestley procured 
oxygen gas from red precipitate, whereas he particularly mentions 
that he obtained it by employing mercurius calcinatus per se : this cir- 
cumstance 



52 Notices respecting New Books. 

cumstance he on one occasion especially notices, observing that no 
nitric acid had been used in preparing it, and consequently that the 
oxygen could not be derived from the decomposition of nitric acid, a 
portion of which is well known sometimes to remain in red precipi- 
tate. 

No directions are given for preparing oxygen gas in the section 
which treats of its properties. We are merely told that recourse is to 
be had to the decomposition of its compounds when we wish to pre- 
pare it ; and in defiance of all propriety, and neglect of all conveni- 
ence, we are directed to see Manganese, Red Oxide of Lead, Red 
Oxide of Mercury, and Chlorate of Potassa, — all of which are treated 
of in the second volume, while the properties of oxygen are described 
in the first. 

With respect to Hydrogen Gas no advice is given to the young ex- 
perimenter to allow it to escape for a short time previously to inflam- 
ing it, or to cover the vessel from which the gas is evolving, in order 
to prevent the ill effects which might arise from an explosion j and 
as to the means by which hydrogen gas is obtained, the omissions 
are, if possible, more glaring than those noticed as to the prepara- 
tion of oxygen gas. Not only are there no directions given for this 
purpose, but we are not even told that they are to be found in a sub- 
sequent part of the work. In one experiment with this gas mention 
is indeed made of '* a mixture which will furnish hydrogen ;" but as to 
its composition, no more is said than if it were a profound secret and 
so intended to remain. It is indeed true that some hints are given 
as to the preparation of hydrogen gas when Water is treated of, but 
they are by no means so ample as they ought to have been. 

In the observations prefixed to the section on Acids, Dr. F. remarks, 
" though Davy considered chlorine and iodine as acidifying principles, 
yet others maintained that hydrogen is the principle of acidity in those 
[acids] not containing oxygen. From the arrangement I have adopted, 
it will be perceived, that if we are really to attach a principle of aci- 
dity to certain bodies, it should be given to hydrogen, because we find 
that sulphur, chlorine and iodine, unite with oxygen, and form one 
set of acids, and with hydrogen to generate another." Now without 
pretending to feel the force of this reasoning, which we do not under- 
stand, there are sufficient facts stated in the quotation to induce us 
to conclude that no acidifying principle whatever exists, especially 
since oxygen and hydrogen both enter into the composition of several 
alkalies. Indeed, to admit of the existence either of an acidifying or 
an alkalifying principle, is in our estimation no more required than 
to allow of a principle of form or of colour. 

We have neither time nor inclination to present the reader with all 
the observations which have occurred to us while perusing the section 
on the Metals. There are, however, some statements respecting a few 
of them which call for remark, and more especially as to iron and its 
compounds. Rust of iron is stated by Dr. Fyfe to be a carbonate : 
but this is not the case $ for no solid compound of carbonic acid and 
perdxide of iron can be formed, and yet similar assertions occur twice 
in subsequent parts of this section. "The only compounds of any 

interest 



Dr. Fyfe's Elements of Chemistry. 53 

interest of iron and the simple acidifiable bodies are those with car- 
bon, sulphur and cyanogen :" this last, however, we need hardly state, 
is a compound of two simple acidifiable bodies. The protosulphuret 
of iron is rather a scarce substance ; and yet Dr. F. states that it is 
employed in the preparation of the sulphate of iron by exposure to air 
and moisture : — now it is the persulphuret, which is a very plentiful 
mineral, that is used for this purpose. 

Respecting the liquor Jerri alkalini of the London Pharmacopoeia 
Dr. Fyfe has committed several mistakes. In the first place " It is" 
not " much used j" secondly, the solution of carbonate of potash must 
not be added to the solution of pernitrate of iron, but the latter to the 
former. The following remarks show indeed that Dr. F. is equally 
ignorant of the nature of the process, and of the product obtained by it. 
"In the first part of the process, a pernitrate of iron, but with a large 
excess of acid, is formed ; and in the second, this excess is merely 
saturated by the alcaline solution, a part of the iron being precipitated 
in the state of a carbonate, but which is instantly dissolved by the 
nitric acid ; so that the product is a mixture of nitrates of iron and of 
potass." Now as the acid solution is added to the alkaline one, in- 
stead of the reverse as here stated, the precipitate formed is not dis- 
solved by the nitric acid, but by the carbonate of potash j so that the 
product is not a mixture of nitrates of iron and potash, but a solution 
of carbonate 'of potash holding peroxide of iron in combination, and 
mixed with nitrate of potash. That the solution contains no nitrate 
of iron might almost have been learned from the name, absurd as it 
is, which the London College have given to this preparation. It is 
sufficiently ridiculous to speak of alkaline iron j but it would have been 
worse than this to have bestowed a name denoting alkalinity, where 
none was in existence. 

The sulphas ferri exsiccatus of the Edinburgh Pharmacopoeia is not 
deprived of the whole of the water of crystallization $ it retains one 
atom of water. According to Dr. Fyfe, colcothar is used " for making 
razor-strops :" we supposed they had been made of wood and leather, 
and merely covered with colcothar. When the carbonated alkalies 
are employed to decompose sulphate of iron, the protocarbonate is 
not converted into percarbonate by absorbing oxygen, no such com- 
pound exists j — it becomes a mixture of protocarbonate and peroxide 
of iron. " Permuriate [of iron] with the maximum oxid" cannot "be 
prepared by dissolving that oxide or the carbonate in the acid :" it 
must be "that oxide," for the carbonate contains protoxide : by the 
bye, as permuriate with the maximum oxide is so particularly mentioned, 
may we inquire whether there is any permuriate without it ? In the 
London Pharmacopoeia it is not the red oxide of iron which is used for 
preparing the iinctura ferri muriatis, but the ferri subcarbonas, which 
is a mixture of protocarbonate and peroxide : the Edinburgh process 
for the same preparation does not at first yield a protomuriate, for the 
scales of iron employed are a mixture, perhaps a compound, of pro- 
toxide and peroxide of iron. — There are several other statements re^ 
specting the compounds of iron which we are precluded from noticing 

merely 



5* Notices respecting New Books, 

merely for want of room, for we have still a few observations to make 
with regard to some other metallic compounds. 

Copper, according to Dr. Fyfe, is not an abundant production, and yet 
the county of Cornwall alone produces nearly ten thousand tons annu- 
ally. Sulphate of copper according to our author is " always " procured 
by exposing the natural ore containing sulphur and copper to the air. 
We venture to assert that this salt is never now so prepared, nor do we 
believe that it ever was. Is Dr. Fyfe aware of the fact, that with few 
exceptions, the ore of copper is a double sulphuret of that metal and 
iron ? And if a salt were formed from it by the action of air and mois- 
ture, it would undoubtedly be the double sulphate of copper and iron, 
which is a well known compound. 

Dr. Fyfe has, we think, entirely mistaken the nature of the pulvis 
antimonialis. He says that "the oxide of antimony and phosphate of 
lime enter into union and form a triple phosphate of antimony and 
lime." Now it appears to us that there is not the slightest evidence 
of combination existing between the oxide and the phosphate j indeed 
of all substances in nature, phosphate of lime, from its extreme inertness, 
is one of the least likely to combine with a metallic oxide. Nor can we 
assent to the assertion that pulvis antimonialis is one of the best of 
the antimonial preparations : on the contrary, there is the strongest 
evidence to prove that it is generally inert ; and when it possesses 
power, it is impossible to determine the degree of its activity by any 
ordinary means. 

Dr. Fyfe is not more careful in representing the opinions of others 
than in detailing his own j thus he says, << according to Phillips (Ann. 
of Phil. N. S. iv.),when properly manufactured it(pulvis antimonialis) 
should be composed of phosphate of lime and protoxide -, whereas it 
frequently contains the peroxide, and therefore differing from James's 
Powder, which from the analysis of Pearson and Phillips is com- 
posed of 

Phosphate of lime .43 

Protoxide of antimony 57. 

He has found, also, that instead of the oxide and the phosphate being 
in combination, they are frequently merely mixed, and must therefore 
be totally inert as a medicine." 

Now as we readily acquit Dr. Fyfe of all intentional misrepresenta- 
tion, we have no alternative but to suppose that he never read the 
paper to which he above alludes, and from which he appears to quote. 
On referring to Dr. Pearson's analysis, it will be observed that not a 
word is stated with respect to the state of the oxidizement of the an- 
timony j and for a very sufficient reason — nothing at that time, (more 
than thirty years since,) was known on the subject -, and Phillips is 
so far from attributing the inertness of pulvis antimonialis to the ingre- 
dients being merely mixed and not combined, that he considers them 
always mixed and never combined j and he distinctly mentions that he 
found the antimony in James's Powder to be peroxide, not protoxide 
as asserted by Dr. Fyfe. 

It is quite needless to add more instances of Dr. Fyfe's want of 

precision 



Royal Society. 5a 

precision with regard to his statements. We may observe that the 
wood-cuts which he has introduced "are few and far between j" but 
their quality is such, that whether intended for use or ornament, we 
cannot lament their scarcity. 

Unless Dr. Fyfe writes for medical pupils only, he should be careful 
to avoid such terms as aqua potasses and aqua ammonia, which com- 
mon readers might find it difficult to comprehend. — We cannot omit 
to notice the extreme facility with which Dr. Fyfe alters the names 
of the various authors whom he quotes : — thus we have Herschell 
for Herschel, Allan for Allen, Sommerville for Somerville, Philip for 
Phillips, Mayou for Mayow, Creighton for Crichton, Chevreuil for 
Chevreul, Liebeg and Leibeg for Liebig, Daniells for Daniell, Arrago 
for Arago, Dobereigner and Doboreigner for Dobereiner, and many 
other similar mistakes. We observe also that Cryophorus is three 
times written Creophyrus. 

We mark these merely as indications of that want of care and 
correctness which pervades every part of the work ; and all we can 
say in its favour, if indeed that be any thing, is to admit that it is not 
unworthy of the author of the Manual. 

X. Proceedings of Learned Societies. 

ROYAL SOCIETY. 

M q — \ COMMUNICATION was read t0 the Society, con- 
May w. J\ taining some " Particulars of the Earthquake felt in 
the Netherlands, and in some of the Frontier Towns of France, on the 
23d of February last." Extracted from a letter to Captain Sabine, 
from Professor Quetelet, Director of the Royal Observatory at Brus- 
sels. 

The number of earthquakes which are on record as having been 
experienced in the Netherlands, for many centuries past, does not 
exceed six or eight ; and none of them have been productive of dis- 
astrous effects. Within a space of ten years, during the last cen- 
tury, three only took place, one of which happened in 1755, imme- 
diately after the great earthquake at Lisbon j and the last was in 
1760. The one which has lately occurred was particularly felt along 
the banks of the Meuse ; and its greatest violence was felt in the 
towns of Liege, Tongres, Tirelemont, and Huy : many of the walls 
and buildings of which suffered considerable injury g but, happily, no 
lives were lost. In the adjacent towns of Maestricht, Namur, Lou- 
vain, and Brussels, strong shocks were also experienced j but their 
violence diminished in proportion to the distance from the former, or 
principal, seat of concussion. They appear also to have been sen- 
sibly felt at Bonn, Dusseldorf, and Dordrecht, on one side, and at 
Flushing, Middleburg, and Dunkirk, on the other j although they 
were not perceptible at many of the intermediate towns. Slight 
shocks were also experienced at several of the frontier towns of 
France, as Avesnes, Commercy, and Longuyon j as also at the coal- 
mines near Liege, at the depth of from fifty to sixty toises -, in which 

latter 



56 Royal Society. 

latter case they were accompanied by a hollow sound, resembling 
that of a heavily laden waggon. The direction in which the shocks 
were propagated appears to have been from east to west. 

For some time before the earthquake the weather had been fine ; 
but it became cloudy on the evening which preceded it, and conti- 
nued so for several subsequent days. At Brussels the barometer had 
fallen during the three preceding days from 29-421 inches to 29*044 5 
on the night before the earthquake it had risen to 29*126 ; and a few 
moments after the event, it stood at 29*233. It continued after- 
wards to rise j and on the 27th it had reached 30*166. At Liege, 
however, the barometer remained very low after the earthquake. 
The shocks lasted about eight or ten seconds. 
There have been experienced, since the 23d of February, slighter 
shocks ; and these also were preceded by a great depression of the 
barometer. 

" Another communication was also read, giving li an Account of 
some Particulars concerning an Earthquake experienced at Bogota, 
and in the Cordillera between Bogota and Popayan, on the 16th of 
November 1827, and the following days." Contained in a letter 
from Colonel Patrick Campbell, Secretary of Legation, to James 
Bandinel, Esq. of the Foreign Office. Communicated by Captain 
Sabine. 

The earthquake is described by the narrator as occurring suddenly, 
at half-past six o'clock in the evening, whilst he was at dinner. It 
was announced by a loud rumbling noise ; the whole house shook 
with violence j the decanters and glasses on the table being thrown 
down. The family ran for shelter under the door- way of the prin- 
cipal floor, which they had no sooner reached than they witnessed 
the fall of the towers of the cathedral opposite to them, with a dread- 
ful crash. The whole tremor lasted about a minute. The first shock 
consisted of a long, undulating motion ; the next was quick and vio- 
lent j and the party found it difficult to preserve their balance, and 
were affected as if from sea-sickness. The damage sustained by the 
town of Bogota is immense, and has been estimated at about two 
millions of dollars, independently of the destruction of the cathedral, 
which had been completed about nine years ago, and the building of 
which cost 800,000 dollars. The government palace, and almost all 
the public offices and barracks, have either been rendered useless, or 
severely shattered. Of the churches, only those of the Capuchins, 
Carmelites, and the chapel of the convent " de ki Ensenanza," can 
be said to have escaped without injury. Few of the houses above 
one story high are habitable, and even many of the low houses have 
been thrown down. The whole of the upper part of the Barrio del 
Rosorio, consisting of buildings of this latter description, now pre- 
sents nothing but a heap of ruins. Many habitations which had with- 
stood the first shocks, have given way under those which followed, 
although incomparably less violent. The injury to dwellings has 
been remarkably unequal in different parts of the town — some streets 
having only partially suffered, while others are. totally destroyed. 
Amidst this widely spreading destruction, it is fortunate that the loss 

of 



Royal Society, ,57 

of lives has been very inconsiderable, being, in the city of Bogota, 
limited to only five or six persons. 

It appears that the earthquake was not felt much to the north of 
Bogota ; but to the south the devastation has been most extensive. 
Throughout the whole of the plain of Bogota, as far as the towns of 
Purificacion and Neiva, there remains no church or public edifice of 
importance that has not been either overthrown or materially da- 
maged. In the towns of Purificacion and Ibogue, the shock was so 
powerful as to throw down many houses constructed of cane, with 
thatched roofs. In Neiva, not only were all the public buildings de- 
stroyed by the earthquake, but torrents of rain conspired to increase 
the havoc. Even straw-huts were levelled with the ground j and the 
roofs of some of them taking fire, added to the horror of the scene, 
and to the extent of the calamity. Great part of the plain of Neiva 
was inundated : this was productive of considerable loss of lives, par- 
ticularly on the banks of the Magdalena, the current of which was at 
first considerably lessened t but a great flood succeeded, and swept 
down vast quantities of mud and other substances, emitting a strongly 
sulphureous vapour, and attended with a general destruction of the 
fish. 

These and other facts render it probable that some volcanic erup- 
tion took place in Tolima, an old volcano of Tocaima, from the mouth 
of which it is reported, that, of late, dense columns of smoke have 
been seen to arise, and more remarkably so on the day of the earth- 
quake j as also from the ridge of mountains of Santa Anna in Mara- 
quita, and the Paramo of Ruiz, which is a part of the same Cordil- 
lera, and contiguous to that of Tolima. 

Popayan, which is 200 geographical miles S.S.W. of Bogota, has 
also suffered much from the same earthquake ; many houses having 
fallen in consequence of the violent shocks that continued to succeed 
each other every six hours down to the evening of the 1 8th, which 
is the date of the latest intelligence from that place. The torrents 
of rain with which they were accompanied, have proved a great ag- 
gravation to the misery they have created. At Patea, still further to 
the S.S.W. the devastation has been still greater ; some of the largest 
trees having been thrown down by the concussions. It is hence in- 
ferred, that eruptions have taken place at the same period in the vol- 
cano of Pasto ; and the wide crevices which have appeared in the 
road of Guanacas, leave no doubt that the whole of the Cordillera has 
sustained a powerful shock. 

In the plains of Bogota considerable crevices have also opened, 
and the river Tunza has already begun to flow through those which 
have appeared near Costa. In other parts of the Cordillera, al- 
though the earth has continued in motion for a quarter of an hour 
without intermission, the movement has been nearly insensible, and 
observable only by means of the compass or the pendulum. 

May 15. — A paper was read, entitled "A Comparison of the 
Changes of Magnetic Intensity in the Dipping and Horizontal Nee- 
dles throughout the day, at Truernberg Bay, in Spitzbergen." — By 
Captain Henry Foster, R.N. F.R.S. 
New Series. Vol. 4. No. 1 9. July 1 828. I The 



&8 Royal Society. 

The observations made by the author at Port Bo wen, in 1825, on 
the diurnal changes of magnetic intensity taking place in the dipping 
and horizontal needles, appeared to indicate a rotatory motion of the 
polarizing axis of the earth, depending on the relative position of the 
sun, as the cause of these changes. By Captain Foster's remaining 
at Spitzbergen during the late northern voyage of discovery, a fa- 
vourable opportunity was afforded him of prosecuting this inquiry. 
Instead of making the observations with a single needle, variously 
suspended, as had been done at Port Bowen, two were employed ; 
the one adjusted as a dipping needle, and the other suspended hori- 
zontally. The relation between the simultaneous intensities of the 
two needles could thus be ascertained, and inferences deduced rela- 
tive to the question, whether a diurnal variation in the dip existed as 
one of the causes of the observed phenomena • or whether, the dip 
remaining constant, they were occasioned by a change in the inten- 
sity. 

The dipping needle used, was one belonging to the Board of Lon- 
gitude, and made by Dollond :— both this and the horizontal needle 
were made in the form of parallelopipedons, each 6 inches long, 0*4 
broad, and 005 thick. The experiments were continued from the 
30th of July to the 9th of August, and were so arranged, that in the 
course of two days an observation was made every hour in the four- 
and-twentyj that is, part of them in one day, and another part in 
the other day. 

The observations on the horizontal needle were made in the fol- 
lowing manner. After being freely suspended by a silk thread di- 
vested of torsion, the needle was turned somewhat more than 40° out 
of the magnetic meridian, and the oscillations counted only when the 
arc of vibration had decreased to 40°. The times of performing ten 
oscillations were then noted successively, until two hundred were 
completed : the terminal arc, and the temperature of the instrument, 
were also registered. The oscillations of the dipping needle were 
taken as follows : — one hundred with the face of the instrument east, 
previous to those of the horizontal needle being observed j and an- 
other hundred after the latter, with the face west, — a process which 
gives the mean time of observation nearly the same for both needles. 
Two tables are given : the first containing a register of the observa- 
tions ; and the second, the mean proportional intensities at every 
hour, in each needle, deduced from the respective times of the per- 
formance of one hundred oscillations. From a comparison of the 
changes occurring in the two needles, it appears, that at the time 
when an increase took place in the intensity of the dipping needle, 
that of the horizontal needle underwent a corresponding diminution, 
and vice versa. On comparing these results with the hypothesis of 
a rotation of the general polarizing axis of the earth about its mean 
position as a centre, and employing for this investigation the formula? 
given by Mr. Barlow in his Essay on Magnetic Attractions, it is 
found, that the radius of this circle of rotation is very nearly eight 
minutes. The magnitude of this radius, however, will be considerably 
influenced by the sun's declination. 

The 



Royal Society. 59 

The change of intensity of the dipping needle, in as far as it is 
owing to a variation of the dip, would only be in the proportion of 
3726 to 3732 • whereas, its actual amount is found to be one eighty- 
third part of the whole. This, therefore, seems to imply changes in 
the general magnetic intensity of the earth ; but the author, limiting 
his present inquiry to the variations in the dip, concludes that the 
times of the day when these changes are the greatest and the least, 
are such as indicate a constant inflection of the magnetic pole to- 
wards the sun during the diurnal rotation, and to point to the sun as 
the primary agent in the production of these changes. 

May 15. — A paper was also read, entitled, " Experiments relative 
to the 'Effect of Temperature on the Refractive Index and Dispersive 
Power of Expansible Fluids, and on the Influence of these Changes 
in a Telescope with a Fluid Lens." By Peter Barlow, F.R.S. 

In a paper lately read to the Society, the author stated that he had 
not detected any change in the focal length of the telescope by 
changes of temperature j but he has since ascertained that, in order 
to obtain the brightest and most perfect image, the distance of the 
object-glass requires a minute adjustment, amounting to 0*134 of an 
inch, corresponding to an elevation of temperature from 57° to 84°, 
or a depression from 57° to 31°. , 

In order to introduce greater clearness and precision, the author 
proceeds to define certain terms which he finds it necessary to em- 
ploy. By the length of the telescope, he would be understood to 
mean the distance between the object-glass and the focus • by the 
Jiuid focus, that between the fluid lens and the focus -, and by the 
focal power of the telescope, he means the focal length of a telescope 
of the usual construction, which gives the same convergency to the 
rays,. or produces an image of the same size. 

As it is difficult to determine the refractive index of the fluid under 
different circumstances, from which their effect on the focal power of 
the telescope might be computed, Mr. Barlow endeavoured to ascer- 
tain by direct observations the effect of changes of temperature on 
the power of the telescope, and thence computes the corresponding 
change in the refractive index of the fluid. The result is the amount 
of adjustment already stated. The correction for angular measure- 
ments was the 60th part of a second in every minute for every degree 
of thermometric change ; a quantity which, he observes, is too small 
to deserve notice, except in cases of extreme delicacy. The disper- 
sions at 3 1° and at 84° are in the ratio of 3067 to 3084. The change 
in the refractive index between 32° and 212°, supposing it to in- 
crease uniformly, would be about one tenth of the whole, a proportion 
which is very nearly the same as the actual expansion of the fluid. 
Hence the author considers it as probable that in this, and all other 
expansible fluids, the index of refraction varies directly as. the den- 
sity : on the other hand, it would appear that the dispersive ratio re- 
mains at all temperatures constantly the same. 
. May 22d. — A letter was read from Thomas Andrew Knight, Esq., 
addressed to the President, containing " An Account of some Cir- 
cumstances relating to the Economy of Bees." 

12 • In 



60 Royal Society, 

In a former paper the author stated his having observed that, se- 
veral days previous to the settling of a swarm of bees in the cavity of 
a hollow tree adapted to their reception, a considerable number of 
those insects were incessantly employed in examining the state of 
the tree, and particularly of every dead knot above the cavity which 
appeared likely to admit water. He has since had an opportunity of 
noticing, that the bees who performed this task of inspection, instead 
of being the same individuals, as he had formerly imagined, were, in 
fact, a continual succession of different bees : the whole number in 
the course of three days being such as to warrant the inference, that 
not a single labouring bee ever emigrates in a swarm without having 
seen its proposed future habitation- He finds that the same remark 
applies not only to the permanent place of settlement, but also to the 
place where the bees rest temporarily, soon after swarming, in order 
to collect their numbers. 

The swarms which were the subjects of Mr. Knight's experiments 
showed a remarkable disposition to unite under the same queen. On 
one occasion, a swarm which had arisen from one of his hives settled 
upon a bush, at a distance of about twenty-five yards ; but instead of 
collecting together into a compact mass, as they usually do, they re- 
mained thinly dispersed for nearly half an hour, after which, as if 
tired of waiting, they singly, and one after the other, and not in obe- 
dience to any signal, arose and returned home. The next morning 
a swarm issued from a neighbouring hive, and proceeded to the same 
bush upon which the other bees had settled on the preceding day, 
collecting themselves into a mass, as they usually do when their 
queen is present. In a few minutes afterwards a very large assem- 
blage of bees rushed from the hive from which the former swarm had 
issued, and proceeded directly to the one which had just settled, and 
instantly united with them. — The author is led from these and other 
facts to conclude, that such unions of swarms are generally, if not 
always, the result of previous concert and arrangement. 

He next proceeds to mention some circumstances which induce 
him to believe that sex is not given to the eggs of birds, or to the 
spawn of fishes or insects, at any very early period of their growth. 
Female ducks, kept apart from any male bird till the period of laying 
eggs approached, when a musk drake was put into company with 
them, produced a numerous offspring, six out of seven of which 
proved to be males. 

The mule-fishes found in many rivers where the common trout 
abounds, and where a solitary salmon is present, are uniformly of the 
male sex : hence the spawn must have been without sex at the time 
it was deposited by the female. 

Mr. Knight states that he has also met with analogous circum- 
stances in the vegetable world, respecting the sexes of the blossoms 
of monoecious plants. When the heat is excessive, compared with 
the quantity of light which the plant receives, only male flowers ap- 
pear : but if the light be in excess, female flowers alone are produced. 
At this meeting His Royal Highness the Duke of Sussex was elect- 
ed a Fellow of the Royal Society. 

June 



Linnccan Society. 61 

June 5th. — A paper was read, entitled " Description of a Sound- 
ing-Board in Attercliffe Church, near Sheffield." — By the Rev. John 
Blackburn, minister of Attercliffe. 

The church of Attercliffe had long been remarkable for the diffi- 
culty and the indistinctness with which the voice from the pulpit was 
heard : these defects have been completely remedied by the erection 
of a concave sounding-board, having the form resulting from half a 
revolution of one branch of a parabola on its axis. It is made of 
pine-wood ; its axis is inclined forwards to the plane of the floor at 
an angle of about 10 or 15°; it is elevated, so that the speaker's 
mouth may be in the focus j and a small curvilinear portion is re- 
moved on each side from beneath, so that the view of the preacher 
from the side galleries may not be intercepted. A curtain is sus- 
pended from the lower edge, for about' eighteen inches on each side. 
The effect of this sounding-board has been to increase the volume of 
the sound to nearly five times what it was before ; so that the voice 
is now audible, with perfect distinctness, even in the remotest part of 
the church j and more especially in those places, however distant 
they may be, which are situated in the prolongation of the axis of the 
paraboloid. But the side galleries are also benefited, probably from 
the increase of the secondary vibrations excited in a lateral direction. 
Several experiments are related illustrative of these effects • among 
which the most striking was one in which a person placed so as to 
have one ear in the focus of the paraboloid, and the other towards a 
person speaking from the remote end of the church, heard the voice in 
a direction the reverse of that from which it really proceeded. The 
superior distinctness of sounds proceeding from the focus, is ac- 
counted for by their all arriving at the same moment of time, at a 
plane perpendicular to the axis, after reflection from the surface of the 
paraboloid j which is a consequence of the equality of the paths 
which they have described. 



LTNN^AN SOCIETY. 

June 17. — A paper was read, entitled, " Description of a species 
of Tringa killed in Cambridgeshire, new to England and Europe," by 
Wm. Yarrell, Esq. F.L.S. 

The author describes a singularly marked Tringa, which was shot 
in Cambridgeshire in the month of September 1826. 

This bird is rendered more than usually interesting from the cir- 
cumstance that it is not only new to this country, but is acknow- 
ledged by the best practical ornithologists of the day, to be also en- 
tirely new to Europe. It is described by Monsieur Vieillot, under 
the name of Tringa rufescens, as having been found in Louisiana j 
and a single specimen deposited in the Paris Museum has furnished 
the only records known. 

A description of the plumage, and the measurement of various 
parts, are given in detail ; and the paper concludes with a list of the 
more recent additions to British ornithology, accompanied by refer- 
ences to the various authorities from whom the first notices of these 
addenda have emanated. 

ASTRONOMICAL 



62 Astronomical Society. 

ASTRONOMICAL SOCIETY. 

May 9. — A paper was read, entitled " Approximate Places of 
Double Stars in the Southern Hemisphere, for 1827, as observed at 
Paramatta, N.S.Wales. By Mr. James Dunlop." 

After the departure of Sir T. M. Brisbane from the Colony of New- 
South Wales, the author, finding himself in the possession of re- 
flecting telescopes capable of adding considerably to our knowledge 
of the nebulae and double stars of that portion, resolved to remain, 
for the purpose of making a general survey, of the heavens, from the 
south pole to 30° of south declination. The dark nights in the 
absence of the moon were devoted to observations of the nebulae, 
and the moonlight to those of double stars, of which however only 
a part could be subjected to exact micrometrical measurement. 
The apparatus employed for. this purpose consisted of a 46-inch 
achromatic telescope, equatorially mounted, and furnished with two 
micrometers ; — one a parallel-line micrometer, the author's own 
workmanship ; the other, a double-image micrometer, on Amici's 
principle. Those which could not be micrometrically measured, 
had their positions and distances noted by estimation while passing 
the field of the 9-feet reflector, with which they were discovered in 
the sweeps for nebulas, and their places are given as determined in 
the sweeps. 

The author prefaces his catalogue with the details of the microme- 
trical measures of about 30 principal Southern double stars, the most 
remarkable of which are a Crucis and a Centaury the former bear- 
ing a great resemblance, both in the magnitudes and the mutual di- 
stance of its individuals, to Castor; the latter being a star of the first 
magnitude, accompanied by one of the fourth, at about 20" di- 
stance, — a remarkable combination, such as does not occur in our 
hemisphere. 

A Catalogue of 254 double stars arranged in order of right as- 
cension follows, in which the right ascension to seconds of time, 
and declination to the nearer minute of space, — the position, qua- 
drant, distance, the differences of right ascension and declination 
when observed, and the magnitudes, are set down in separate co- 
lumns. They comprise double stars of all classes and of every 
variety. One very remarkable is the star 1 k Argus^ JR. 8 h 4 m , 
declin. —42° 7', which consists of individuals of the sixth and 
eighth magnitudes, the large star being blue, and the small one 
dusky red. This affords almost the only instance known of a com- 
bination of two considerably bright stars differing decidedly in mag- 
nitudes, where a marked excess of the less refrangible rays enters 
into the composition of the light of the smaller star, and of the 
more refrangible into that of the larger. Among the double stars 
is set down also one of the seventh magnitude, right ascension 
l tl 19 m 43 s , declin. —33° 31', of that singular deep red purple co- 
lour of which examples are not wanting in our own hemisphere. 

An extract of a letter was read from Professor Harding, of Got- 
tingen, to Dr. Tiarks, in which he alludes to a phenomenon which 
had recently been observed by several astronomers on the conti- 
nent, relative to an inequality of the dark space between the body 

of 



Astronomical Society. 63 

of Saturn and its ring. This appearance was first noticed by M. 
Schwabe on December 21, 1827, and has since been confirmed by 
several persons to whom M. Harding had communicated the cir- 
cumstance. It seems that the space on the eastern side of the planet 
appears larger than the space on the western side. M. Harding 
was at first inclined to treat the whple as an optical deception, till 
the fact was confirmed by others, when he was induced to attempt 
an explanation of the phenomenon. He endeavoured to account 
for it by the present position of Saturn ; but the result of his cal- 
culation proved that that cause would not increase the space (in 
March) more than Vs-; a quantity probably too small to become 
perceptible to the eye. He indeed imagined that the appearance 
might be caused by the shadow of the body, which at present falls 
much beyond the south-eastern part of the ring, and which might 
render it impossible to perceive the equality of the two spaces. 
But this, he says, is disproved by the observation of M. Schwabe^who 
saw the same phenomenon on the 31st of December, three weeks 
before the opposition, when the shadow was on the western side, 
and could be but faintly discerned. M. Harding is unable to ex- 
plain it as an optical deception, and yet cannot consider it in any 
other light at present. Actual measurement, he says, can alone 
decide the question. He has already written to M. Struve to take 
some measures with his powerful telescope, and he requests that 
this communication may, with the same view, be forwarded to 
Messrs. Herschel and South, who have the best means, in this coun- 
try, of determining this singular phenomenon. 

Mr. South then read a note, which he had annexed to the above 
communication, stating that in compliance with M. Harding's 
wishes, Mr. Herschel and himself had directed their attention to 
Saturn, but that they did not detect any inequality in the two spaces 
above alluded to, by means of micrometers attached to his 5-feet 
equatorial. The mean of 35 measures, taken on April 26, April 29, 
and May 8, gave the preceding (or western) space 3"*532; and the 
following (or eastern) space 3"*607. At the same time he remarks 
that the mean of 20 measures taken on April 26 (viz. 10 by 
Mr. Herschel and 10 by himself) gave the spaces precisely the 
same ; each being 3"*472. Mr. Herschel's measures gave the pre- 
ceding (or western) space 3"*612; and the following (or eastern) 
space 3"*442 ; whilst his own gave the former 3"*331, and the lat- 
ter 3"-502. Mr. South adds, however, that Mr. Herschel, after a 
careful examination, thought that, beyond all doubt, the following 
(or eastern) space appeared the larger: and it is a remarkable 
fact, that of seven persons who were present in Mr. South's ob- 
servatory shortly afterwards, and who successively viewed Saturn 
through his 5-feet equatorial, six of them gave it as their opinion 
that the apparent right (or eastern) space was the larger : whilst 
the other observer declared he could not distinguish any difference. 
The situation, however, of Saturn was so low, as to render most of 
these observations far from satisfactory. 

M. Harding also alludes in his letter to the reappearance of the 

variable 



61- Royal Institution of Great Britain. 

variable star in the constellation Serpens, mentioned in No. 5. of 
the Society's monthly notices. (See Phil. Mag. N. S. vol. ii p. 226.) 
He says, it is now again become visible, and has already attained the 
8th or 9th magnitude. Its position for the beginning of this year is 

M = 15" 46 m 45 s Decl. = + 15° 39' 30" 
and he invites astronomers to watch this star during the period of 
its changes. 

A communication was then read from Mr. Rumker of the obser- 
vatory at Paramatta in New South Wales, giving an account of his 
observations for determining the absolute length of the pendulum 
vibrating seconds there, according to Borda's method. The ap- 
paratus, with which these experiments were made, was constructed 
by Fortin, of Paris, and taken out to the colony by Sir Thomas 
Brisbane. There are some slight alterations from the apparatus 
described by M. Biot, which are pointed out by Mr. Rumker : and 
he also alludes to a new method of observing the coincidences. In 
Borda's method, the coincidence is determined by the intersection 
of the wire of the pendulum of experiment with a cross marked on 
the bob of the pendulum of the clock. In lieu of this cross, Mr. 
Rumker placed a small graduated arc, and the determination of the 
coincidence resolves itself into observing the moment when the wire 
describes its minimum amplitude on the arc. Mr. Rumker likewise 
adopts a new mode of determining the correction for the arc of vi- 
bration. He finds that in large arcs (such as 8 or 9 degrees, to 
which his arcs sometimes extend) the decrease is not in a geome- 
trical progression, when the times are in arithmetical progression. 
He has therefore formed a table of the actual decrease of the arcs 
as observed by himself, at equal intervals of five minutes each ; and 
given the corresponding corrections for each interval. In the course 
of his reductions he notices some errors in the formula given by 
M. Biot for finding the centre of oscillation of a pendulum con- 
structed according to the method of Borda. The mean of 41 series 
of experiments gives the length of the pendulum, vibrating seconds 
at Paramatta, in vacuo, at the freezing point, and at the level of the 
sea, equal to 992-412801 millimetres, or 39-071618 English inches. 



PROCEEDINGS AT THE FRIDAY-EVENING MEETINGS OF THE 
ROYAL INSTITUTION OF GREAT BRITAIN. 

May 23. — Mr. Brockedon on a new method of projecting shot. 
— This method belongs to Mr. Sievier. It consists in making the shot 
with a cylindrical chamber, so as to pass freely on to a maundril or 
bar fixed on trunnions, a powder-chamber being formed at the bottom 
of the cylindrical cavity in the shot. The powder is inflamed by 
means of a touch-hole in the shot, in the usual way. A charge of 
powder thus used is found to produce effects very much surpassing 
that occasioned when a shot of equal weight is thrown from a can- 
non ; and this is accounted for by supposing that the force, of recoil, 
which in a cannon is so great as to throw it a considerable distance 

backwards, 



Intelligence and Miscellaneous Articles. 65 

backwards, is added in the new form of shot to the usual quantity of 
projectile force. The experiments made with shot weighing up to 
twenty-five pounds, were successful both as to force and direction 3 
and the extraordinary advantage gained as to lightness in the appa- 
ratus necessary to throw the shot, was proved by one man taking all 
that was necessary to Primrose-hill, the place of experiment. 

Some fine fulgurites or lightning sand-tubes were placed on the 
library tables. 

May 30. — Mr. Curtis gave a lecture on the structure and physi- 
ology of the Ear in man and animals, illustrated by drawings and 
anatomical preparations. 

June 6. — Mr. Burnet gave an illustrated account of the experi- 
ments recently made by himself and Mr. Mayo, on the irritability of 
the sensitive plant, and extended his observations to the irritability 
and supposed nervous structure of plants in general. Their experi- 
ments accord with those of Dutrochet, as far as the two series run 
parallel. When a sensitive plant has been made to droop, Mr. Burnet 
finds that if the part in which the moving power resides is blackened 
so as to absorb the light of the sun, the restoration of the plant to its 
natural state is very much longer before it takes place. He also 
found that at the moment the expansion at the foot of the leaflets or 
other parts were touched to produce the motion of the plant, it 
changed colour. 

June 13. — A full account of the recent and present state of the 
Thames Tunnel was given by Mr. Faraday, illustrated by Mr. 
Brunei's drawings and models. The peculiar nature of the ground 
in which the tunnel lies, the occurrence of springs in the soil, the 
extraordinary manner in which they affect it during the rise and fall 
of the tide, were stated and explained ; and then the present state 
of the tunnel, now perfectly free from water, and the intentions of 
the engineer with regard to its future progress, were described. 

These evening meetings then closed for the season. 



XL Intelligence and Miscellaneous Articles. 

DIRECT METHOD OF ASCERTAINING THE VELOCITY OF CAN- 
NON-BALLS. 

L1EUT.-GEN. HELVIG, in the Prussian service, has invented a 
direct and certain method of measuring the time which a can- 
non ball or bullet takes to pass through a certain space. His process 
consists in disengaging by means of the ball or bullet the detent of 
a third's watch (une detente de montre d, tierce) at the moment when 
the ball or bullet quits the mouth of the piece, and to stop the same 
watch by means of the ball or bullet at the instant when it reaches 
the mark. The numerous experiments which he has made, present 
already the most interesting results. He has communicated this 
notice in order to establish his right to the invention, but intends 
shortly to publish a full detail of his experiments upon the subject. — 
Bulletin des Sciences Militaires, p. 119. 

New Series. Vol. 4. No. 19. July 1828. K chryso- 



66 Intelligence an$ Miscellaneous Articles. 

CHRYSOLITE IN THE CAVITIES OF OBSIDIAN. 

Professor Gustavus Rose of Berlin has found in the cavities of 
obsidian, in the Jacal Rock near Real-del-Monte in Mexico, little 
crystals, greenish, and reddish-yellow, and transparent, which be- 
long to the species of prismatic chrysolite.— Poggendorff's Annalen, 
vol. x. p. 323. 

METEOR OF A GREEN COLOUR. 

[Communicated by Mr. B. D. Silliman, in a letter dated New York, 
March 1, 1828.] 

On the night of the 1 1th of February, between 1 1 and 12 o'clock, 
as 1 was crossing the East River, between this city and Long Island, 
1 observed a beautiful meteor which was visible for about the space 
of two seconds. Its course was from a point perhaps 5° below the 
zenith, toward the horizon in a N.E. direction. It described an arc 
of perhaps 20°, when it apparently exploded, but without any re- 
port that I could hear. Its colour was a singularly pure grass green, 
of a light shade ; the trail which it left was of the same colour, and 
so were the scintillations which accompanied its apparent explosion. 
The latter were distinct, like those accompanying the bursting of a 
rocket, but by no means so numerous. — Two gentlemen who were 
in the boat with me at the time, also saw it. — Silliman s Journal* 



BITTER OF ALOES. — CARBAZOTIC ACID. 

It is well known that the peculiar substance produced by the action 
of nitric acid upon aloes, combines with bases, and forms salts which 
detonate by heat ; this substance is the aloetic acid of M. Braconnot. 
Mr. Liebig formerly made some experiments on this substance, 
{Ann. de Chim. Mai 1827,) but they were not satisfactory. He has 
lately renewed his experiments, and finds that the detonating prin- 
ciple is carbazotic acid. 

The bitter of aloes is plentifully obtained by the action of nitric 
acid of sp. gr. 1'25. With potash it forms a purple salt, which is 
but slightly soluble, which precipitates the salts of barytes, lead, and 
peroxide of iron in flocks of a deep purple colour ; the protonitrate of 
mercury is precipitated of a light red. In order to decompose the 
salt of potash, it was decomposed by acetate of lead; and, contrary to 
all expectation, the weight of the precipitate was less than that of 
the potash-salt employed. The washings were of a yellow colour, and 
deposited crystals of the same. These crystals, treated with heat 
and sulphate of potash, yielded carbazotate of potash, from which the 
carbazotic acid was separated. 

When aloes are heated with nitric acid of 1*432 as long as vapours 
of nitrous acid are disengaged, and on afterwards mixing the liquor 
with a little water to separate the bitter, there may be obtained by 
saturating the liquor with potash and evaporation, a large quantity 
of carbazotate of potash in fine crystals. The bitter of aloes is con- 
sequently a compound of a peculiar substance, possessing the proper- 
ties of the resins, and carbazotic acid. 

Wool, 



Intelligence and Miscellaneous Articles. 67 

Wool, morphia, narcotine, and myrrh, yielded no carbazotic acid 
when treated with nitric acid. — Anncles de Chimie, Fev. 1828. 



HEAT DEVELOPED DURING COMBUSTION, 

M. Despretz finds that when equal quantities of oxygen are used 
for the combustion of the following substances, the annexed propor- 
tions of heat are developed : 

Hydrogen 2578° 

Charcoal 2967 

Iron 5325 

Phosphorus, zinc, and tin give nearly the same quantities as iron. 
It appears then that of all bodies, hydrogen develops the least heat 
for the same proportion of oxygen gas absorbed ; the metals disen- 
gage the most. It is remarkable that carbon, which does not alter 
the volume of the gas, evolves a quantity of heat which is equal to 
three-fifths of that given out by iron and the metals in general. — Ibid. 



ON THE SUGAR OF LIQUORICE-ROOT. 

Dobereiner and Robiquet have long since given processes for the 
purification of this substance ; the latter precipitates it by vinegar. 
Berzelius separates it in the following manner. The liquorice-root 
is to be sliced and infused in boiling water ; when cold the infusion 
is to be filtered, and' sulphuric acid added to it gradually, as long as 
precipitation occurs. This precipitate is a compound of the acid with 
the saccharine matter. It is first to be washed with acidulated cold 
water, and then with pure water, till it ceases to be rendered acid : 
the precipitate is afterwards to be digested with alcohol which sepa- 
rates the vegetable albumen and dissolves the compound of sugar 
and sulphuric acid j there is then to be gradually added to the solu- 
tion carbonate of potash or soda in fine powder, and when it ceases 
to be acid, it is to be decanted and evaporated. It is proper to leave 
a very slight excess of acid in the solution, and for this purpose it is 
convenient to set aside a portion to be afterwards added to the satu- 
rated solution, until it is rendered weakly acid. The liquor is then 
to remain in order that the sulphate of potash may separate, and af- 
terwards it is to be evaporated. 

The saccharine matter is obtained in the form of a yellow trans- 
parent mass, which breaks into a coarse powder resembling amber — 
when heated in the air it swells up, inflames, and burns with a bright 
flame, but with smoke. When in powder it burns like the lycopodium 
or powdered resin. It suffers no change by exposure to the air. 
The aqueous solution is precipitated by all acids, and the more per- 
fectly as the solution is more concentrated, and especially if excess 
of acid be used. The washed precipitates have no sour taste, but on 
the contrary a pure saccharine flavour which is developed in a short 
time. The precipitates are soluble in boiling water, and on cooling a 
yellow transparent jelly is formed if the solution be concentrated. Al- 
cohol also dissolves them, and they burn without leaving any residuum. 

The saccharine matter of liquorice combines also readily with 

K 2 bases ; 



68 Intelligence and Miscellaneous Articles. 

bases ; it is on this account very difficult to separate it from acids, 
without its retaining a portion of the bases employed for that pur- 
pose. The compounds with the alkalies dissolve readily in water, 
but with difficulty in alcohol ; when they are perfectly saturated they 
contain no trace of carbonic acid, even when bases combined with 
carbonic acid have been employed, and their taste is purely saccha- 
rine, without mixture of alkalinity. The compounds formed with ba- 
rytes and lime are soluble and are not precipitated by carbonic acid j 
this saccharine matter forms insoluble compounds with the metallic 
acids, — when poured into a solution of acetate of lead, a precipitate is 
formed, which when decomposed by sulphuretted hydrogen, forms a 
black liquid, in which the suiphuret of lead remains suspended j if it 
were not for this, it would be a good method of obtaining pure sac- 
charine matter : the same v substance is obtainable from the inspis- 
sated liquorice juice ; but it is black and cannot be decolorized. It 
unites not only with acids and bases like the yellow saccharine mat- 
ter, but also with salts, such as the sulphates of barytes, lime and 
potash. It precipitates many metallic salts. — Ibid. 



SOLUTION IN SULPHURIC ACID WITHOUT OXIDIZEMENT. 

Vogel of Bayreuth,whilst examining anhydrous sulphuric acid, found 
that sulphur by being put into contact with it, imparted to it a fine 
blue colour, which passes to green or brown by the addition of a 
greater quantity of sulphur. Water precipitates sulphur from these 
combinations, and heat decomposes them. It appeared probable 
that the sulphur was simply held in solution by the sulphuric acid, 
and M. Magnus mentions several analogous cases, which leave no 
doubt on the subject. 

Miiller of Reichenstein discovered long since that powdered tellu- 
rium when sprinkled with concentrated sulphuric acid, was dissolved 
and became a perfectly transparent fluid of a fine crimson-red colour 
without observing any evolution of gas, or smell of sulphurous acid. 
On the addition of a proper quantity of water the tellurium is preci- 
pitated in the state of a deep blackish-brown metallic powder. This 
solution may be kept for a long time in a close vessel, without any 
alteration ; but if it attract moisture from the air, it gradually changes 
into sulphate of oxide of tellurium, and continually exhales the odour 
of sulphurous acid. This change is readily effected with the assist- 
ance of heat. Selenium is also dissolved by sulphuric acid, the solu- 
tion is of a very fine green colour, and a few drops of water precipi- 
tate the selenium of a red colour. 

Tellurium and selenium act like sulphur with sulphuric acid ; ex- 
cept that sulphur requires for its solution that the acid should be an- 
hydrous. These three bodies are oxidized when the sulphuric acid 
attracts moisture gradually, and exhale an odour of sulphurous acid j 
but if the water be added quickly, they are then precipitated. Lastly, 
the three solutions are coloured — that of the sulphur being blue, 
green or brown, the tellurium crimson-red, and the selenium green. 

According to Bussy, iodine is also soluble in anhydrous sulphuric 
acid, and gives it a blueish green colour. 

It 



Intelligence and Miscellaneous Articles. 69 

It follows from these facts that sulphuric acid has the property not 
only of dissolving compound bodies without oxidizing them, as Ber- 
zelius has shown with respect to the metallic cyanurets, but it dis- 
solves some simple bodies, such as sulphur and selenium, for the 
oxides of which it has no affinity, and also tellurium, with the oxide 
of which it forms a crystallizable compound. — Ibid. 

_ • 

VEGETABLE ALBUMEN AND GELATINE. 

Beccaria discovered, as is well known, a peculiar glutinous prin- 
ciple in wheat, which is obtained by working the flour in water, and " 
which he called gluten. Taddei has given an account of two new pe- 
culiar principles which he supposes he has found in gluten, and which 
he has named gliadine and zymome. The other kinds of grain yield no 
principle similar to the gluten of Beccaria. But Einhof, in his remark- 
able analysis of rye, barley and pease, has shown that these seeds 
contain a substance analogous to the gluten of wheat, but which dis- 
solves in water during the manipulation. Having had occasion to 
make some experiments on the gluten of Beccaria, 1 found that Tad- 
dei had only given two new names to the known and common prin- 
ciples of plants, particularly the seeds of the graminece. 

If the gluten of Beccaria be boiled with alcohol, as long as this 
fluid grows turbid on cooling, a considerable portion of the mass is 
separated j if water be added to this spirituous solution, and the mix- 
ture be distilled, the watery fluid remaining in the retort deposits on 
cooling a coherent glutinous matter, perfectly resembling gluten. 
This is vegetable gelatin, the gluten, of the same nature as the mat- 
ter separated, according to Einhof s method, from rye and barley. 
The matter insoluble in alcohol, whilst moist is semitransparent, and 
so much like animal albumen, that it is impossible to distinguish by 
its appearance only, that it is vegetable albumen, or, as Wahlenberg 
calls it, with good reason, the white of grain. Caustic alkali, when 
the solution is weak and cold, dissolves vegetable albumen, and 
leaves the filaments of starch which it has retained. The following 
are the principal properties of vegetable albumen. This matter, ob- 
tained after the evaporation of the alcohol from the remaining liquor, 
is of a yellowish gray colour, adhesive, glutinous, and very elastic ; it 
has no taste, but it has a peculiar smell. In a dry atmosphere it be- 
comes shining on the surface, and gradually dries into a mass of a 
deep yellow colour, and is perfectly transparent, resembling dry ani- 
mal matter. It dissolves in alcohol, and the solution is of a pale 
yellow colour, and remains after the evaporation of the spirit, in the 
form of transparent yellow varnish. When vegetable gelatine is 
treated with cold alcohol, a milky fluid is obtained, and a viscid 
white matter remains. This matter is not vegetable gelatine ; it is 
dissolved by boiling, but the liquor becomes milky on cooling. If 
the vegetable gelatine be dissolved with heat in weak spirit of wine, 
it precipitates on cooling, retaining its glutinous property j it dis- 
solves in vinegar, leaving a white viscid matter, which the acid does 
not dissolve even when boiling, but which partly passes through the 
filter. When precipitated from its solution in vinegar by an alkali, 

it 



70 Intelligence and Miscellaneous Articles, 

it retains its glutinous state. With the mineral acids it forms a glu- 
tinous compound, insoluble in water, until the excess of acid is re- 
moved, and it is then as perfectly precipitated from this solution as 
from that in vinegar, when more acid is added. The phosphoric 
acid is however an exception, for it does not precipitate the acid so- 
lutions. Vegetable gelatine also combines with the caustic alkalies, 
and when the gelatine is in excess, a solution is obtained, which is 
so perfectly neutral that no alkaline taste remains. It gives by eva- 
poration a transparent mass, which is again soluble in water, which 
leaves undissolved the greater part of the viscid principle. Ammonia 
and lime-water precipitate vegetable gelatine from solution in acids, 
and redissolve it j but if it be aggregated these alkalies do not dis- 
solve it, or at least the solution is slowly effected. With the earths 
and. the metallic oxides, vegetable albumen forms insoluble com- 
pounds ; the alkaline carbonates precipitate vegetable albumen from 
solution in the caustic alkalies or in the acids. The precipitate is a 
compound of the gelatine with the alkali, which without the liquid is 
not gelatinous. The persulphate of iron does not precipitate vege- 
table gelatine from solution in vinegar. On the contrary, it is pre- 
cipitated from its acid solutions by the ferrocyanate of potash, in a 
hard, white, semitranspafent mass, which is deposited on the sides 
of the vessels. It is also precipitated from solution, either in acid or 
alkali, by the permuriate of mercury and tincture of galls. The ge- 
latine, in the solid state, is tanned in the two solutions, exactly like 
animal gelatine. The viscid principle, which has been several times 
mentioned, has not had its properties examined. The best method 
of separating it is to treat vegetable gelatine with concentrated vine- 
gar, and when the mass is thoroughly penetrated, to mix it in the cold 
with weak alcohol, which dissolves the acetate of gelatine, and the 
undissolved matter is also to be washed with cold weak spirit. It 
dries into a colourless transparent body, which yields ammonia by 
distillation. It swells in alcohol and becomes viscid ; when heated in 
it, solution takes place, but it is precipitated on cooling. 

Vegetable albumen, when dissolved to saturation in weak alkaline 
solutions, possesses in so great a degree the properties of white of 
egg, that, as is well known, it has been mistaken for it. Its solution 
in potash, when the latter is not in excess, has no alkaline taste 
whatever. It coagulates slightly by ebullition, but it is generally 
retained by the alkali ; it combines with acids. The solution when 
perfectly saturated is soluble in water, but an excess of acid precipi- 
tates it j vinegar and phosphoric acid, however, are exceptions to this, 
for they may be added in large quantity, without occasioning precipi- 
tation. Before treatment with potash, vegetable albumen when boiled 
in alcohol dissolves sparingly in vinegar or phosphoric acid ; but 
when boiled with these acids, it forms a transparent jelly, which is 
colourless and bulky. With permuriate of mercury, tincture of galls, 
and ferrocyanate of potash, it acts like animal albumen. 

The French chemists have considered the azotized principle con- 
tained in emulsive seeds as analogous to cheese in milk. Soubeiran 
has shown that this principle in almonds, similar to that which has 

been 



Intelligence and Miscellaneous Articles, 71 

been described, possesses the properties of white of egg, but not 
those of cheese j and Payen and Henry, who had considered the re- 
sults obtained by Soubeiran as opposed to theirs, are convinced by 
new trials, that this principle cannot be considered as caseum, but 
that it ought to be called albumino-caseous. I add, that according to 
its properties, it is rarely identical with vegetable albumen. — Ibid. 

BERZELIU8. 

ANHYDROUS CRYSTALS OF SULPHATE OF SODA. 

In the Number for April of the Royal Institution Journal, Mr. Faraday 
makes the following observations with respect to this salt : — If a drop 
of a solution of sulphate of soda be placed upon a glass plate and al- 
lowed to evaporate spontaneously, it will leave crystals which may 
be distinguished by their form and alternate efflorescence as being 
the salt in question. Most of the potash and soda salts may be dis- 
tinguished as to their base by such an experiment. They are easily 
converted into sulphates by a drop or two of sulphuric acid and ig- 
nition j and then being dissolved and tried as above, will yield 
crystals which may be known by their forms, and more especially by 
their efflorescence if of soda, and their unchangeable state if of potash. 
This test is, however, in some circumstances liable to uncertainty, 
arising from a curious cause. If the drop of solution on the glass be 
allowed to evaporate at common temperatures, then the efflorescence 
takes place, and the distinction is so far perfect j but if the glass plate 
with the drop upon it be placed upon a warm part of a sand-bath or 
hot iron-plate, or in any other situation of a certain temperature con- 
siderably beneath the boiling point of the solution, the crystals which 
are left upon evaporation of the fluid are smaller in quantity, more 
similar in appearance to sulphate of soda, and finally do not efflo- 
resce. Upon examining the cause of this difference I found they 
were anhydrous, consequently incapable of efflorescing, and indeed, 
exactly of the same nature as the crystals obtained by Dr. Thomson 
from certain hot saturated leys. — Ann. Phil. N. S. xx. 201. 

Hence it would appear, that a mere difference in the temperature 
at which a solution of sulphate of soda is evaporated, will cause the 
formation of hydrated or anhydrous crystals at pleasure, and that 
whether the quantity of the solution be large or small. This indeed 
might have been expected from what takes place when hydrated 
crystals of sulphate of soda are carefully melted j a portion dissolves, 
and a portion separates, — the latter in an anhydrous state. (Quarterly 
Journal, xix. p. 153.) I find that, if it were desirable, crystallized an- 
hydrous sulphate of soda might easily be prepared for the market 5 
though, as the pure salt is now but little used, it is not likely this 
condensed form will be required. Whenever a salt of soda is to be 
distinguished from one of potash in the manner above described, this 
effect of temperature must be carefully guarded against. 

CASEOUS OXIDE, AND CASEIC ACID. 

The results obtained by Proust relative to the substance produced 
by the fermentation of cheese, have been described and examined by 

M. Henri 



72 Intelligence and Miscellaneous Articles. 

M. Henri Braconnot. The substance which Proust distinguished as 
caseous oxide, he shows to have no claim to such a title, and proposes 
to call it aposepedine, as being produced by putrefaction. It also ap- 
pears to be produced in certain diseases. The properties which 
Proust has assigned to caseic acid, belong, according to M. Braconnot, 
to various contaminating substances, none of which have any title to 
be considered as a particular acid. The substances present are free 
acetic acid; aposepedine; animal matter, soluble in water and insoluble 
in alcohol (ozmazome) ; animal matter, soluble in both water and 
alcohol; a yellow, acrid, fluid oil ; a brown resin ; acetate and muriate 
of potash, and traces of acetate of ammonia. 

On examining the fatty matter of cheese, Braconnot found it to 
consist of margarate of lime with margaric and oleic acids ; the butter 
having undergone the same kind of change during the fermentation 
of cheese, as that produced when it is saponified by the action of al- 
kalies or other bodies. — Ann. de Chim. xxxvi. p. 159. 



RIB OF A WHALE FOUND IN THE DILUVIUM OF BRIGHTON 
CLIFFS. 

A short time since some labourers employed in collecting flints 
from the beach near Kemp Town (a new suburb erecting to the east 
of Brighton), observed the extremity of a large bone projecting from 
the base of the cliff. They immediately broke off a portion of it, but 
the remainder was fortunately so impacted in the rock that they were 
unable to remove it without more labour than they were willing to 
bestow. Intelligence of the discovery having reached Mr. Mantell of 
Castle Place, Lewes, he visited the spot, and assisted by the labourers, 
succeeded in making an excavation to the extent of three or four 
yards in the cliff, and completely exposed the bone without injuring 
it in the slightest degree ; but unfortunately in attempting to remove 
it subsequently, it fell to pieces*. This fragment of bone (for it evi- 
dently was but a small portion of the original) measured nine feet in 
length, the piece destroyed by the workmen was estimated at about 
three feet, so that the specimen when first discovered must have been 
twelve feet long ; from its slight degree of curvature it could not have 
been less than thirty feet when entire. The circumference of the 
largest extremity was thirty-four inches, and the bone gradually di- 
minished in size, terminating obtusely. The surface was almost flat 
on the inner side of the curvature, and convex on the outer, corre- 
sponding in this respect with the ribs of the common whale. From 
a mere fragment of bone, however gigantic, it is of course impossible 
to decide positively as to the animal to which it belonged ; yet as 
this example was too enormous to have belonged to any terrestrial 
animal, and not only in form but also in structure bore a close ana- 
logy to the rib of a whale, it may with but little hesitation be consi- 
dered as the sternal portion of a rib of that animal. According to 

* A fragment five feet long was, however, removed to Mr. Mantell's 
museum. 

Mr. 



Intelligence and Miscellaneous Articles, 73 

Mr. Mantell's description of the cliffs at Brighton, (Geology of 
Sussex, p. 277,) they consist of 

1. Calcareous bed, composed of the ruin of chalk strata with clay, 

&c., fifty to sixty feet thick. 

2. Bed of shingle or pebbles, five to eight feet. 

• 3. Sand, three to four feet, with boulders of granite, porphyry, 
slate, &c. 
4. Upper chalk, forming the sea-shore. 

The bone was imbedded in the sand No. 3, lying beneath the 
shingle bed and upon the chalk. Vast quantities of the teeth of the 
horse, and a few of a species of ox, and of the elephant (£. primi- 
genius), have lately been discovered in the calcareous bed. 

_ 

INEQUALITY OF THE DARK SPACE BETWEEN THE BODY OF SA- 
TURN AND ITS RING. 

Do the observations of Sir W. Herschel on an apparent irregu- 
larity in the figure of Saturn, (recorded in the Philosophical Transac- 
tions for 1808, p. 160,) throw any light upon the recent observa- 
tions of MM. Schwabe and Harding, and of Messrs. Herschel and 
South, on the apparent inequality of the dark space between the 
body of this planet and its ring, as noticed in No. 12 of the Monthly 
Notices of the Astronomical Society, which has just been circulated ? 

Inquirer. 



NATIVE IRON f SLIGHTLY ARSENIURETTED. 

The substance described below, was brought to me two or three 
weeks since, by Mr. Philo Baldwin* , who stated that it was from 
Bedford county, Pennsylvania, in which county we believe Mr. B. 
lives. 

Perceiving that it was a singular modification of iron, and different 
from any thing I was acquainted with, — it was, at my request, sub- 
mitted by Mr. S. to chemical examination. 

My impressions are, that it is a new variety of native iron, and 
that it differs from that substance only by containing a little arsenic, 
with a little plumbago. Measures will be taken to obtain a greater 
supply, as it is stated to be abundant, and will at least form an inter- 
esting addition to our cabinets. 

Chemical examination* — The fragment weighed, I should judge, 
two or three ounces j and although it had sustained considerable in- 
jury, it evidently formed a distinct crystal. By observing a symme- 
trical modification which this crystal had undergone, in the truncation 
of two of its alternate obtuse solid angles, I was able easily to ascer- 
tain, that it belonged to the class of rhombic prisms, but whether 
the prism was right or oblique, I could not determine The natural 
planes were not sufficiently even, to allow of the determination of 

* Mr. Baldwin went to Newtown, Connecticut, where he formerly re- 
sided, and was to return in a week to learn the nature of the mineral, but 
has not yet called, which prevents me from stating the exact locality. — B. S. 

New Series. Vol. 4. No. 19. July 1828. L their 



74 Intelligence and Miscellaneous Articles. 



"O 



their angles with perfect accuracy : neither were the results, from 
numerous cleavage-planes, uniform enough for this purpose ; although 
in the latter case the reflective goniometer was used with the utmost 
convenience. The inclination of the primary planes may be regarded 
as an approximation to 121° and 59°, and those of the secondary 
(intersecting the base parallel to its greater diagonal ) to the primary 
146°. With the cleavage-crystals the following angles were ob- 
tained, 120°, 121°, and 122°; a diversity very remarkable, as the 
cleavages appeared to the eye quite perfect, and the planes highly 
uniform. 

The cleavage parallel to the lateral planes is effected without much 
difficulty, whilst no terminal one is visible j it breaking in that direc- 
tion with great difficulty, and presenting an uneven and sub-hackly 
fracture. The external planes of the crystals before being broken, 
were dull and nearly black, owing to a thin coating of brown oxide 
of iron ; but fresh cleavages presented a fine metallic lustre, and a 
colour between silver-white and steel-gray. It breaks with the greatest 
difficulty, and small masses often flatten under the blow of the ham- 
mer, like pure iron. Its hardness is almost that of ordinary steel. 
Specific gravity, in distilled water at 60° F., 7*337. It is highly mag- 
netic, with polarity so distinct as to take up iron filings. Before the 
blowpipe it melts. 

Fragments of the size of a pea, brought within the exterior flame 
of the compound blowpipe, emitted a very slight vapour, in which 
the well-known odour of arsenic was detected : and immediately on 
coming within the inner cone of flame, they burnt with intense 
energy, and with a most brilliant light, throwing out a profusion of 
scintillations, after the manner of pure iron, or more like a burning 
watch-spring. No odour of sulphur was perceived in these trials. 
In order, however, to make myself sure of the absence of sulphur, I 
resorted to the following experiment. A portion of the metal was 
dissolved in dilute nitric acid : the solution was supersaturated with 
potash and boiled in the alkaline liquor ; the precipitate was sepa- 
rated, and the supernatant fluid neutralized by nitric acid, to which 
was afterwards added nitrate of lead ; the precipitate was separated, 
and found to be perfectly soluble in dilute nitric acid, thus evincing 
the absence of sulphate of lead, which must have formed part of the 
precipitate, provided sulphur had existed in the mineral under ex- 
amination. 

After having examined it in the usual modes, for silver, gold, and 
other metals, and not discovering any to be present*, I dissolved 
fifty grains in nitric acid, with a view to ascertain merely the pro- 
portion of iron present. After the solution appeared to be effected, 
I observed a number of little black flakes floating in the liquid, which 
resisted the action of the acid. These being separated by the filter, 
were examined and found to be plumbago, which, under somewhat 

* After the iron had all been removed from the nitric solution by am- 
monia, and the fluid boiled, hydro-sulphuret of ammonia gave no cloudi- 
ness, thus evincing the absence of nickel. 

similar 



Intelligence and Miscellaneous Articles. 75 

similar circumstances, though less disguised and more abundant, 
was found in the native iron of Canaan. They weighed 0*2 grs. and 
from other trials, appear to exist in the mineral pretty constantly in 
this proportion. The nitric solution was precipitated by ammonia, 
and the residuum after drying indicated 48*7 grs. of metallic iron. 

I afterwards repeated my examination with greater care in the 
following manner. Twenty-five grs. were dissolved in dilute nitric 
acid. This solution was boiled for some time with an excess of soda, 
and deposited 35 grs. of the peroxide of iron. The supernatant li- 
quor with the washings of the precipitate being evaporated and neu- 
tralized by nitric acid, was decomposed by nitrate of lead, and af- 
forded a precipitate weighing 1*5 gr. which upon burning charcoal 
gave the smell of arsenic, and was entirely soluble in nitric acid, and 
therefore consisted wholly of arseniate of lead. The result of my 
trial, then, would be as follows, after deducting the weight of the 
plumbago: for 24*9 of the mineral, 

Iron 24*263 

Arsenic "389 

24-652 
Loss -248 

24-9 
Which gives per hundred of the mineral, free from the plumbago, 

Iron 97-44 

Arsenic . . 1*56 

99 
Loss 1 

100 
This therefore cannot but be regarded as a singular substance, 
especially as it affords us an instance of the remarkable effect pro- 
duced by a small proportion of arsenic in disguising the natural pro- 
perties of iron. Whether it coincides with the species described by 
Mohs under the name of axotomous arsenical pyrites, (to which opi- 
nion I am rather inclined, from its crystalline character and specific 
gravity,) or whether it constitutes a distinct species in mineralogy, 
I will not at present venture to assert. When an additional supply 
of this substance shall be furnished us for examination, and the means 
of comparing it with some genuine specimens of the above-mentioned 
species shall occur, it will be very easy to decide upon this point. 
Yale College, March 4th, 1828. Charles U. Shepard. 



ARSENIATE OF COBALT. 

Arseniate of cobalt has been lately discovered at the lead mine of 
Tyne Bottpm, about three miles south of the town of Alston in Cum- 
berland, by Mr. H. L. Pattinson, Assay Master for the Commissioners 
and Governors of Greenwich Hospital, in the Manor of Alston Moor. 
It occurs in the form of a rose-coloured efflorescence, investing he- 

L 2 patic 



76 New Patents. 

patic and common pyrites ; and specimens in great plenty are to be 
picked up on the old mining heaps. The veins at Tyne Bottom bear 
nearly east and west, and are worked in a limestone stratum called 
the Tyne Bottom Limestone in Mr. Westgarth Forster's section of 
the strata which occur in that district. They were formerly very pro- 
ductive of lead-ore ; and beautiful specimens of transparent and finely 
crystallized carbonate of lime were obtained, but for a few years past 
the quantity of ore yielded has not been considerable. 



SOLAR SPOTS, &C. 

On the 27th of May, thirty- two maculae or black spots, in groups, 
were observed on the sun's disc; the largest with its umbra ex- 
ceeded by admeasurement the circular extent of the earth, and was 
situated near the central part of the arc which formed the lower 
right-hand quadrant. The nucleus of this spot, or the opening in 
the sun's atmosphere (a rational hypothesis of the late Dr. Herschel), 
was in the shape of a mans hat t and the well-defined speckled umbra 
nearly so, with the exception of the angular parts. Seven of the 
largest spots were in a line near the sun's centre, and four near the 
upper limb ; most of the others were interspersed about the largest, 
which went off the visible part of the disc by means of the sun's 
motion on its axis in the night of the 29th. 

The apparent angular distance of the planet Venus from the sun's 
centre at the time of its greatest eastern elongation on the 19th, 
was 45° 28' 30", when its appearance was like the moon at her last 
quarter with an inverting telescope, or at her first quarter without 
an inversion. This planet, which is the most radiant in the solar 
system, and which now casts a faint shadow in the evening after 
twilight, may be seen with the naked eye in the open day in clear 
weather during the next four weeks. 



LIST OF NEW PATENTS. 

To W. Marshall, of Fountain Grove, Huddersfield, for improve- 
ments in machinery for cutting or shearing, cropping and finishing 
cloth, &c— Dated the 26th of April 1828.— 2 months allowed to enrol 
specification. 

To T. Breidenback, of Birmingham, for a machine or improved 
mode for forming tubes or rods, &c. — 26th of April. — 4 months. 

To J. GrifTen, of Withy Moor Works, near Dudley, for an improve- 
ment in the manufacturing of scythe backs, chaff-knife backs, and hay- 
knife backs. — 26th of April.— 6 months. 

To J. J. Watt, of Stracey-street, Stepney, for his discovery of the 
application of a certain chemical agent by which animal poison may 
be destroyed and the disease consequent thereon effectually prevent- 
ed. — 26th of April. — 6 months. 

To C. C. Bompas, of the Inner Temple, Esq., for his improvements 
in the propelling of locomotive carriages and machines, and boats 
and other vessels. — 29th of April. — 6 months. 

To 



. New Patents. 77 

, To T. Hillman, of Mill-wall, Poplar, for improvements in the con- 
struction and fastening of masts.— 1st of May. — 6 months. 

To J. Brownill, of Sheffield, for his improved method of transferring 
vessels from a higher to a lower level, or from a lower to a higher 
level on canals, and also for the more conveniently raising or lower- 
ing of weights, carriages, or goods, on rail-roads, &c. — 1st of May. 
— 6 months. 

To J. Palmer, of Globe-road, Mile-End, for improvements in the 
moulds, machinery or apparatus, for making paper. — 6th of May — 
6 months. 

To T. Adams, of Oldbury, Salop, for improvements on trusses, or 
apparatus for the relief or cure of rupture. — 6th of May. — 6 months. 

To F. Westby, of Leicester, for his apparatus to be used for the 
purpose of whetting or sharpening the edges of the blades of knives, 
&c. — 6th of May. — 2 months. 

To Rear Admiral Brooking, of Plymouth, for a turning or shipping 
fid for securing and releasing the upper masts of 6hips and vessels. — 
6th of May — 6 months. 

To M. Fulwood, of Stratford, Essex, for a cement, mastic or com- 
position, denominated German Cement. — 6th of May. — 2 months. 

To J. B. Macneil, of Foleshill, Coventry, for improvements in pre- 
paring and applying materials for constructing or rendering more 
durable roads, which materials are applicable to other purposes. — 6th 
of May. — 6 months. 

To T. Jackson, of Red-Lion-street, Holborn, for a new metal stud 
to be applied to boots, shoes, and other like articles of manufacture. 
— 13th of May. — 6 months. 

To J. Ford, of Wands worth-road ,Vauxhall, for improvements in ma- 
chinery for clearing, opening, scribbling, carding, combing, slubbing 
and spinning wool, and for carding, roving, or shivering and spinning 
cotton, short-stapled flax, hemp and silk, either separately or com- 
bined, and for spinning or twisting long-stapled flax, hemp, silk, 
mohair, &c. and either separately or combined. — 13th of May. — 6 mo. 

To T. Bonsar Crompton, of Tamworth, in Lancashire, and E. Tay- 
lor, of Marsden in Yorkshire, for improvements in the process of pa- 
per-making which relates to the cutting. — 13th of May. — 2 months. 

To C. Chubb, of St. Paul's Churchyard, London, for improvements 
in the construction of door-latches. — 17th of May. — 6 months. 

To T. W. and J. Powell, of Bristol, for improvements in the pro- 
cess of forming moulds for refining sugar, and in the application of 
materials hitherto unused in making the said moulds. — 1 7th of May. 
— 2 months. 

To T. Aspinwall, of Bishopsgate Churchyard, London, Esq., for an 
improved method of casting printing types by means of a mechanical 
process. Communicated from abroad. 22nd of May. — 6 months. 

To S. Hall, of Basford, Nottinghamshire, for an apparatus for ge- 
nerating steam and various gases to produce motive power, and for 
other useful purposes. — 31st of May. — 6 months. 

To J. Moft'at, of King's Arms-yard, Coleman -street, London, for 
an improvement in apparatus for stoppering and securing chain ca- 
bles ; 



78 Meteorological Observations for May 1828. 

bles ; also for weighing anchors attached to such chain or other cables, 
either with or without a messenger.T~3rd of June. — 6 months. 

To D. Jobbins, of Uley, Gloucestershire, for an improved method, 
by certain machinery applicable to stocks or fulling-machines, of 
milling and scowering woollen cloths, &c. — 3rd June. — 2 months. 

To Baron Charles Wettersted, of Commercial-place, Commercial- 
road, for a liquid or composition for water-proofing and strengthen- 
ing leather. — 4th of June. — 6 months. 

To R. Wilty, of Hauley, Staffordshire, for improvements in appa- 
ratus for making coal-gas. — 10th of June. — 6 months. 

To E. G. Atherley, of York-place, Portm an -square, for an appara- 
tus for a method of generating power. — 12th of June.— 6 months. 

To W. Strachan, of Avon Eitha, Ruabon, Denbighshire, for an im- 
provement in the making of alum. — 12th of June. — 4 months. 

To J. Bartlett, of Chard, Somersetshire, for a new method of pre- 
paring flax-thread or yarn for use in the manufacture of boots, shoes, 
sadlery $ and of sail and of other cloths and bagging. — J 6th of June. 
— 2 months. 

To G. J. Young, of Newcastle-upon-Tyne, for a machine whereby 
an additional and improved purchase or power .will be given in work- 
ing ships, windlasses, and capstans. — 21st of June. — 6 months. 

METEOROLOGICAL OBSERVATIONS FOR MAY 1828. 

Gosport. — Numerical Results for the Month, 

Barom. Max. 30-32 May 1. Wind NE.— Min. 29-36 May 24. Wind S. 
Range of the index 0-96. 

Mean barometrical pressure for the month 29-826 

Spaces described by the rising and falling of the mercury 4-120 

Greatest variation in 24 hours 0-440. — Number of changes 18. 
Therm. Max. 76° May 16. Wind S.— Min. 42° May 8. Wind N.E. 
Range 34°.— Mean temp, of exter. air 58°-76. For 3 1" days with in fc 56*42 
Max. var. in 24 hours 24°-00— Mean temp, of spring water at 8 A.M. 51°-29 

De Luc's Whalebone Hygrometer. 

Greatest humidity of the air in the evening of the 11th 84° 

Greatest dryness of the air in the afternoon of the 15th 40 

Range of the index 44 

Mean at 2 P.M. 53°-0 —Mean at 8 A.M. 57°'0— Mean at 8 P.M. 64-9 

of three observations each day at 8, 2, and 8 o'clock 58-3 

Evaporation for the month 3-95 inches. 

Rain near ground 2-29 inches. , 

Prevailing wind, S.E. 

Summary of the Weather. 
A clear sky, 5; fine, with various modifications of clouds, 12|; an over- 
cast sky without rain, 8; rain, 5£. — Total 31 days. 
Clouds. 
Cirrus. Cirrocumulus. Cirrostratus. Stratus. Cumulus. Cumulostr. Nimbus 
23 20 27. 27 24 21 

Scale of the prevailing Winds. 
N. N.E. E. S.E. S. S.W. W. N.W. Days. 
1 5 4 7 2J b\ 3 3 31 

General 



Meteorological Observations Jo?- May 1828. 79 

General Observations. — The state of the weather this month has been 
changeable, except in the second week, and showery, with several frosty 
mornings, and intervals of hot sunshine ; but upon the whole it has been a 
fine growing month for the corn and vegetation, with mild nights in ge- 
neral. The hoar frosts in the mornings of the 6th, 7th, 9th and 10th, and 
the cold blighting winds on several subsequent days, have much injured the 
late bloom of the wall and other fruit trees, and caused a great part of 
the fruit that was set to fall off'. The vines will not be so prolific this year 
as they have been for two or three years past. The grass fields in this 
neighbourhood have been much improved by the recent showers, and from 
their fine appearance a good crop may be expected : the grass in several 
fields is already cut. 

The chaffers were first observed here in the evening of the 6th, and have 
been unusually numerous, having been seen on the wing every fine day 
since. On the 14th, a quarter of an hour before sunset, a large meteor 
was observed in the N.W. at an altitude of about 40 degrees. Its light 
was vivid, and its descent rapid and nearly perpendicular ; the disjoined 
parts continued luminous several seconds of time after its explosion. Its 
appearance so early was remarkable, as meteors are very seldom seen till 
after the evening twilight. 

In the night of the 15th there was thunder, and sheet-lightning the fol- 
lowing night for several hours, after a very warm day : thunder and light- 
ning also occurred in the evening of the 23rd. 

The mean temperature of the external air this month is more than three 
degrees higher than the mean of May for the last twelve years. 

Th.e atmospheric and meteoric phcenomena that have come within our 
observations this month, are one lunar and two solar halos, three meteors, 
thunder and lightning twice; and six gales of wind, or days on which they 
have prevailed ; namely, one from the North-east, three from the South- 
east, one from the South, and one from the West. 



REMARKS. 



London. — May l. Very fine. 2. Fine: slight rain at night. 3. Drizzly: 
Cloudy. 4. Fine : rain at night. 5. Cloudy. 6. Sultry : with thunder. 
7. Fine : drizzly at night. 8. Fine. 9. Showery. 10. Fine. 11. Cloudy. 
12 — 15. Very fine. 16. Sultry: much lightning at night. 17 — 20. Very 
fine. 21. Cloudy: with showers. 22. Cloudy morning : fine. 23. Very 
fine. 24. Heavy rain in morning : showery. 25. Fine. 26. Showery. 
27. Fine morning : showery. 28. Fine. 29. Showery. 30. Very fine. 
31. Fine. 

Boston. — May 1, 2. Fine. 3. Cloudy. 4. Cloudy: rain p.m. 5. Rain. 
6. Fine. 7. Cloudy. 8, 9. Fine. 10, 11. Cloudy. 12—15. Fine. 
16. Cloudy. 17— 19. Fine. 20. Cloudy. 21. Fine. 22, 23. Cloudy. 
24. Rain. 25, 26. Cloudy. 27, 28. Fine. 29, Rain. 30, 31. Fine. 

Penzance. — May 1. Clear. 2. Fair. 3. Fair: a shower. 4. Clear: 
showers. 5— 10. Clear. 11. Fair: clear. 12, 13. Clear. 14. Clear: 
fair. 15. Clear: rain. 1 6. Fair : rain at night. 1 7. Rain : clear. 18. Clear: 
fair. 19. Rain. 20. Cloudy : rain. 21. Rain: showers. 22, 23. Fair: 
showers. 24. Rain : blowing strong. 25. Fair. 26. Rain: showers. 27,28. 
Fair : showers. 29. Clear. 30. Clear : fair. 31. Rain: clear. — Rain-gauge 
ground level. 



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THE 

PHILOSOPHICAL MAGAZINE 

AND 

ANNALS OF PHILOSOPHY. 

[NEW SERIES.] 



AUGUST 1828. 



XII. On Webster it e found in the Plastic Clay of Auteuil, near 
Paris. By M. Alexandre Brongniart, Member of the 
Royal Academy of Sciences, and Professor of Mineralogy at 
the Jardin du JRoi, Paris.* 

HPHE occurrence of the same geognostic circumstances, in 
•*■ districts considered to be of the same formation though 
situated very remotely from each other, exhibiting even in the 
beds least developed, a repetition of the most minute particu- 
lars, — presents a phenomenon that cannot but attract the at- 
tention of naturalists ; and appears to point out, that causes, 
simple, but powerful and general, have concurred in produ- 
cing the several strata deposited in each successive epoch. 

These reflections have followed from a discovery I have made 
in the environs of Paris, of a substance which, in itself, is com- 
paratively of little importance : but it is precisely because the 
beds in which it is found are so feebly and irregularly developed 
as scarcely to be entitled to rank as a formation, and because 
this substance, occurring in small nodules, is possessed of cha- 
racters not very important when taken separately, that we are 
struck with its appearance in so many places situated widely 
apart. 

We are not surprised at finding granite of similar composi- 
tion in Europe, Asia, and America : but it is more singular to 
observe Websterite always in the same formation in Germany, 
England, in several parts of France, and even at the gates of 
Paris. 

The mineral substance which forms the subject of the present 
communication, is the subsulphate of alumina, which was found 
first at Halle in Saxony, and which had been long known by 

* Extracted from the " Annales des Sciences Naturelles" for March 1828. 
New Series. Vol. 4. No. 20. Aug. 1828. M the 



82 Prof. Brongniart on Websterite found 

the erroneous appellation of native ahtmina; afterwards by that 
of aluminite (already appropriated to aluminous schist), and 
which I have in another place* named Websterite, dedicating 
it to Mr. Webster of London f , who first discovered this sub- 
stance at Newhaven, near Brighton. 

The history of this mineral, independently of the geological 
circumstances connected with it, is very remarkable f. It was 
at first, and for a long time, taken for pure alumina ; though, as 
it was difficult to imagine how such a substance could exist in 
a state of perfect purity in the midst of very recent beds, its 
origin was rather attributed to some of the processes of a ma- 
nufacture which formerly existed in the spot where it was 
found. In fact, its aspect, and its form (that of nodules about 
the size of nuts), its position so near the surface of the earth, 
and its being the only example which had till then occurred 
of this substance; lastly, the complete ignorance in which we 
were of the date of the stratum in which it had been met with, — 
all contributed to excite the idea that it was merely a product 
of art accidentally buried in the loose soil. 

Afterwards its properties were more carefully examined: 
first Mr. Schreiber observed its crystalline structure, which is 
not visible but by the microscope § ; then MM. Simon, of Ber- 
lin, and Bucholz detected the presence of sulphuric acid. 
M. Chenevix supposed that it was a sulphate of alumina hav- 
ing the base in excess ; and finally, M. Stromeyer proved that 
it was a subsulphate of alumina in definite proportions, con- 
taining 47 per cent of water, or a combination of one atom of 
alumina, one atom of sulphuric acid, and 9 atoms of water. 
AZ.S4- 9Aq. 

Mr. Webster having discovered a similar mineral at New- 
haven ||, M. Stromeyer determined its composition to be the same 
as that found at Halle : afterwards M. de Basterot meeting with 

a white 

* See the Supplement to Vol. iii. of the Dictionnaire des Sciences Na- 
turelle, article Argile Native. 

f Late Secretary and Curator of the Museum of the Geological Society 
of London, and now Professional Geologist and Lecturer on Geology. 

% This history was given much in detail by Keferstein (Leonh. tasch., 
10th year 1816, p. 33) j and M. Bonnard has inserted an abridgement of it 
in the Annates des Mines, 1821, torn. vi. p. 588. 

§ I have verified this observation, and have described it in my Traite 
elementaire de Mineratogie, published in 1807, t. i. p. 515; M. Keferstein 
repeated it, and rendered the results more interesting by comparing them 
with the microscopic appearance of other earthy substances. 

|| In the enumeration of facts respecting the history of this mineral sub- 
stance, it may be proper to observe, that it was in 1812 that Mr. Webster 
found it at Newhaven : shortly afterwards it was determined by Dr. Wol- 
Iaston and Mr. Tennant to be a subsulphate of alumina ; and the latter 

gentleman 



in tke Plastic Clay of Auteuil, near Paris. 83 

a white earthy substance at Bernon, near to Epernay, in the 
lignite of that canton, M. Lassaigne analysed it, and found it to 
be also a subsulphate of alumina, but differing somewhat in the 
proportion of its constituents, owing probably to some impuri- 
ties ; for it is proper to state that Websterite appears always 
as a white friable earth, and that it is difficult to detach it en- 
tirely from the clayey matrix which surrounds it. 

But it is a singularity in this mineral, which I have con- 
stantly observed in the three examples just mentioned, that it 
is composed of an infinity of minute acicular crystals, so small 
that they cannot be seen without a microscope with a magni- 
fying power of at least 400 times : then the crystals are very 
distinct. M. Schreiber had remarked them in the Websterite 
of Halle : I found them in that of Newhaven and Epernay ; 
and by means of the fine microscope of Amici, I have been 
enabled to determine that they consist of six-sided compressed 
prisms terminated by two culminating facets, consequendy 
having a form incompatible with that of alum. 

The three examples of Websterite found in places very di- 
stant from each other, possess therefore the two classes of 
characters which essentially constitute mineral species, parti- 
cular composition and form. Let us now examine their geo- 
logical situation ; and this will not be a useless repetition, 
since we may thus avoid describing the same circumstances 
in detail, when speaking of the Websterite of Auteuil. 

The Websterite of Newhaven has shown clearly the geo- 
gnostic position of this mineral : it is there in nodules of from 
one inch to two or three inches in diameter, imbedded in an 
ochrey clay mixed with gypsum, which is placed upon the chalk, 
and which penetrates in irregular veins the superior and dis- 
integrated part of the rock. That of Bernon, near Epernay, 
found by M. Basterot, occurs also in veins and nodules, in 
the plastic clay above the chalk, accompanied by lignite and 
gypsum. 

If, after having acquired these ideas respecting the position 
of Websterite in two points more than 100 leagues asunder, we 
should extend our observation to Halle in Saxony, 200 leagues 
further, we shall there find, instead a supposed ordinary allu- 
vial soil, the plastic clay with its gypsum, its lignites, its am- 
ber, and its Websterite disseminated in nodules through the for- 



gcntleman inserted a notice respecting it in the Journal de Physique^ for 
September 1814. Previous to that time all the knowledge respecting it in 
England, seemed to be confined to the notice of the substance found at 
Halle, and which was described in our elementary books as native alumine. 
— Edit. 

M 2 , mation. 



84» Prof. Brongniart on Websterite^ fyc. 

mation. At Mori also, not far from the last-mentioned spot, 
we meet with a similar substance, determined by M. Stro- 
meyer to contain the same principles as that of Halle. 

We have next to consider a new variety of this mineral, 
which is met with at Auteuil, and which is properly the sub- 
ject of this memoir. 

The chalk which supports all the superior sedimentary 
strata in the basin of Paris is seen uncovered at Meudon, but 
does not appear on the right bank of the Seine ; it is however 
very near the surface under the hills called Point-du-Jour ; 
and also near Auteuil it carries the plastic clay, which covers 
it in many points. Indeed, this clay is worked at the foot of 
the village of Auteuil, in a place called la Glaciere, and is used 
for making bricks and other purposes. It was in this spot, or 
very near it, that M. Becquerel found in the plastic clay, lig- 
nite, pyrites, sulphate of strontian, phosphate of lime, and 
even a little blende : there also are procured the large well- 
defined and clear crystals of gypsum, so much prized by ama- 
teurs of fine minerals. This locality, in the part where I have 
examined it, exhibits, immediately under the vegetable soil, a 
plastic clay yellowish and very sandy, having little tenacity, 
traversed by veins of yellowish clay still more sandy, ochrey, 
and divided into many small portions. Beneath, is a blueish 
plastic clay that is more tenacious, and contains a good deal 
of pyrites and gypsum. Still lower, is a bed of sand, or rather 
yellow ferruginous coarse gravel ; and below that another bed 
of clay. In this upper yellowish clay we find, and rather in 
nodules than in veins, some parts that are whitish and friable, 
composed of a multitude of small roundish grains, closely con- 
nected together, yet admitting a greyish clay in the interstices. 
When these little masses are cut across, they present the aspect 
of an oolite consisting of white grains in a greyish paste or 
cement. This is Websterite. Each grain, when closely ex- 
amined, appears to be a little spheroid of a structure indi- 
stinctly radiated. When crushed, the powder is very brilliant 
and soft to the touch ; and when examined by the microscope, 
exhibits wedge-shaped masses composed of prisms, but so ill- 
determined, that it is necessary to be aware of their crystal- 
line structure to recognize them. 

It is from these characters that I conjectured this white 
oolitic substance to be Websterite ; but the complete chemical 
analysis made by M. Dumas leaves no doubt as to its nature. 
It does not effervesce with nitric acid, which proves that the 
argillaceous interposed part is not marl, but plastic clay. 
When heated in a glass tube, water rises at first ; but when 
the tube becomes red hot, sulphurous acid is disengaged in 

great 



Sir H. Davy on the Phenomena of Volcanoes. 85 

great abundance. Treated by the blowpipe with nitrate of 
cobalt, it assumes the fine blue colour which denotes alumina. 

It dissolves almost entirely in caustic potash ; and this so- 
lution affords by nitric acid a precipitate which is redissolved 
by an excess of acid. This last solution is precipitated by 
ammonia and by barytes. 

These experiments sufficiently prove the presence of water, 
alumina, and sulphuric acid, and also the absence of silica. 

The complete analysis by M. J. Dumas gives 

Sulphuric acid 23 

Alumina 30 

Water 47 

and this result agrees in the constituent principles and their 
proportions with those of the Websterite of Halle and New- 
haven. 

Thus, we perceive, as I have stated in the commencement 
of this notice, that this friable substance, which has more the 
appearance of an adventitious earthy mixture than of a mineral 
species, presents in its composition, an identity of principles, 
together with a precision in their proportions, rarely found in 
crystallized minerals, which indicate, by their solidity and lim- 
pidity, species completely limited. We see it also placed in 
geological positions and circumstances of which the constancy 
is no less striking. There is, however, between the Web- 
sterite of Autueil, and that of other localities, a slight differ- 
ence of structure, which may serve to establish a variety in this 
species. It has the oolitic structure ; and we may therefore 
distinguish it by the name of Oolitic Websterite of Auteuil. 



XIII. On the Phenomena of Volcanoes. By Sir Humphry 
Davy, Bart. F.R.S.* 

WHEN in the years 1807 and 1808 I discovered that the 
alkalies and the earths were composed of inflammable 
matter united to oxygen, a number of inquiries suggested 
themselves with respect to various parts of chemical science, 
some of which were capable of being immediately assisted by 
experiment, and others required for their solution a long series 
of observations, and circumstances obtained only with diffi- 
culty. Of the last kind were the inferences concerning the 
geological appearances connected with these discoveries. 

The metals of the alkalies, and those of such of the earths 
as I had decomposed, were found to be highly combustible, 
and altered by air and water even at the usual temperatures 

* From the Philosophical Transactions, for 1828. Part I. 

of 



86 Sir H. Davy on the Phenomena of Volcanoes, 

of the atmosphere ; it was not possible, consequently, that they 
should be found at the surface of the globe, but probable that 
they might exist in the interior : and allowing this hypothesis, 
it became easy to account for volcanic fires, *by exposure of 
the metals of earths and alkalies to air and water ; and to ex- 
plain, not only the formation of lavas, but likewise that of ba- 
salts and many other crystalline rocks, from the slow cooling 
of the products of combustion or oxidation of the newly-dis- 
covered substances. 

I developed this opinion in a paper on the decomposition 
of the earths, published in 1808; and since 1812 I have en- 
deavoured to gain evidence respecting it by examining volcanic 
phenomena of ancient and recent occurrence in various parts 
of Europe. 

In this communication I shall have the honour of laying 
before the Royal Society some results of my inquiries. If they 
do not solve the problem respecting the cause of volcanic fires, 
they will, I trust, be found to offer some elucidations of t}ie 
subject, and may serve as the foundation of future labours. 

The active volcano on which I have made my observations 
is Vesuvius ; and there probably does not exist another so ad- 
mirably fitted for the purpose: its vicinity to a great city; the 
facility with which it may be ascended in every season of the 
year; and the nature of its activity, — all offer peculiar advan- 
tages to the philosophic inquirer. 

I had made several observations on Vesuvius in the springs 
of 1814 and 1815, which I shall refer to on a future occasion 
in these pages ; but it was in December 1819, and January and 
February 1820, that the volcano offered the most favourable 
opportunity for investigation. On my arrival at Naples, De- 
cember 4, 1 found that there had been a small eruption a few 
days before, and that a stream of lava was flowing with con- 
siderable activity from an aperture in the mountain a little be- 
low the crater. On the 5th I ascended the mountain, and ex- 
amined the crater and the stream of lava. The crater emitted 
so large a quantity of smoke, with muriatic and sulphurous 
acid fumes, that it was impossible to approach it except in the 
direction of the wind ; and it threw up every two or three mi- 
nutes showers of red hot stones. The lava was flowing from 
an aperture about one hundred yards below it, being appa- 
rently forced out by elastic fluids with a noise like that made by 
the steam disengaged from a pressure engine; it rose, perfectly 
fluid, forming a stream of from five to six feet in diameter, and 
immediately fell, as a cataract, into a chasm about forty feet 
below, where it was lost under a kind of bridge formed of 
cooled lava ; but it re-appeared sixty or seventy yards further 

down. 



Sir H. Davy on the Phenomena of Volcanoes. 87 

down. Where it issued from the mountain, it was nearly white 
hot, and exhibited an appearance similar to that which is shown 
when a pole of wood is introduced into the melted copper of 
a foundry, its surface appearing in violent agitation, large bub- 
bles rising, which in bursting produced a white smoke ; but 
the lava became of a red colour, though still visible in the sun- 
shine, where it issued from under the bridge. The force with 
which it flowed was so great, that the strength of the guide, a 
very stout young man, was insufficient to keep a long iron rod 
in the current. The whole of its course, with two or three 
interruptions where it flowed under a cooled surface, was 
nearly three quarters of a mile, and it threw off clouds of a 
white smoke. It smoked less as it cooled and became pasty ; 
but even where it terminated in moving masses of scoria, smoke 
was still visible, which became more distinct whenever the 
scoria was moved, or the red hot lava in the interior exposed. 

Having ascertained that it was possible to approach within 
four or five feet of the lava, and to examine the vapour imme- 
diately close to the aperture, I returned the next day, having 
provided the means of making a number of experiments on the 
nature of the lava, and of the elastic fluids with which it was 
accompanied. I found the aperture nearly in the same state 
as the day before, but the lava spread over a larger surface, 
forming an eddy in the hollow of the rock, over which it fell, 
from which it could be raised in an iron ladle more easily than 
from the current, and where there was much more facility of 
placing and withdrawing substances intended to be exposed 
to its agency. 

One of the most important points to be ascertained was, 
whether any combustion was going on at the moment the lava 
issued from the mountain. There was certainly no appearance 
of more vivid ignition when it was exposed to air, nor did it 
glow with more intensity when it was raised into the air by an 
iron ladle. I put the circumstance, however, beyond the possi- 
bility of doubt : I threw some of the fused lava into a glass 
bottle furnished with a ground stopper, containing siliceous 
sand in the bottom : I closed it at the moment, and examined 
the air on my return. A measure of it mixed with a measure 
of nitrous gas gave exactly the same degree of diminution as 
a measure of common air which had been collected in another 
bottle on the mountain. 

I threw upon the surface of the lava nitre, both in mass and 
in powder. After this salt had fused, there was a little in- 
crease of vividness in the ignition of the lava, but much too 
slight to be referred to pure combustible matter in any quan- 
tity ; and on making the experiment on a portion of lava taken 

up 



88 Sir H. Davy on the Phenomena of Volcanoes. 

up in the ladle, it appeared that the disengagement of heat 
was partly owing to the peroxidation of the protoxide of iron, 
and to the combination of the alkali of the nitre with the earthy 
basis of the lava ; for where the nitre had melted, the colour 
had changed from olive to brown. This conclusion was still 
further proved by the circumstance that chlorate of potash 
thrown upon the lava did not increase its degree of ignition so 
much as nitre. When a stick of wood was introduced into a 
portion of the lava so as to leave a little carbonaceous matter 
on its surface, nitre or chlorate of potassa then thrown upon 
it caused it to glow with great brilliancy. Some fused lava 
was thrown into water, and a glass bottle filled with water held 
over it to collect the gas disengaged ; it was in very minute 
quantity only, and when analysed on my return proved to be 
common air a little less pure than that disengaged from the 
water by boiling. A wire of copper of g^th of an inch in 
diameter, and a wire of silver of ^th, introduced into the lava 
near its source, were instantly fused : an iron rod of }th of an 
inch, with a piece of iron wire of about y \jth, were kept for 
Ave minutes in the eddy in the stream of lava ; they were not 
fused ; they did not produce any smell of sulphuretted hydro- 
gen when acted on by muriatic acid. A tin-plate funnel filled 
with cold water was held in the fumes disengaged with so much 
violence from the aperture through which the lava issued : 
fluid was immediately condensed upon it, which was of an acid 
and subastringent taste. It did not precipitate muriate of 
baryta ; but copiously precipitated nitrate of silver, and ren- 
dered the triple prussiate of potassa of a bright blue. When 
the same funnel was held in the white fumes above the lava 
where it entered the bridge, no fluid was precipitated upon it, 
but it became coated with a white powder which had the taste 
and chemical qualities of common salt, and proved to be this 
substance absolutely pure. A bottle of water holding about 
| of a pint, with a long narrow neck, was emptied immediately 
in the aperture from which the vapours pressing out the lava 
issued, and the neck was immediately closed. This air ex- 
amined on my return was found to give no absorption with 
solution of potassa ; so that it contained no notable proportion 
of carbonic acid, and it consisted of 9 parts of oxygen and 91 
of azote. There was not the least smell of sulphurous acid in 
the vapour from the aperture, nor were the fumes of muriatic 
acid so strong as to be unpleasant ; but during the last quarter 
of an hour that I was engaged in these experiments, the wind 
changed, and blew the smoke from the crater upon the spot 
where I was standing : the sulphurous acid gas in the fumes 
was highly irritating to the organs of respiration, and I suf- 
fered 



Sir H. Davy on the Phenomena of Volcanoes. 89 

fered so much from the exposure to them that I was obliged 
to descend ; and the effect was not transient, for a violent ca- 
tarrhal affection ensued, which prevented me for a month from 
again ascending the mountain. 

On the 6th of January I made another visit to Vesuvius. I 
found the appearance of the lava considerably changed ; the 
bocca from which it issued on the 5th of December was closed, 
and the current now flowed quietly and without noise from a 
chasm in the cooled lava about three hundred feet lower down. 
The heat was evidently less intense. I repeated my experi- 
ments with nitre with the same results, and exposed pure sil- 
ver and platinum to the fused lava : they were not at all changed 
in colour. I collected the sublimations from various parts of 
the cooled lava above. The rocks near the ancient bocca were 
entirely covered with white, yellow, and reddish saline sub- 
stances. I found one specimen of large saline crystals in a 
cavity, which had a slight tint of purple : this examined, proved 
to be common salt with a minute portion of muriate of cobalt. 
The other sublimations consisted of common salt in great ex- 
cess, much chloride of iron, some sulphate of soda ; and by 
the test of muriate of platinum, there appeared to exist in them 
a small quantity of sulphate or muriate of potassa ; and a so- 
lution of ammonia detected the presence of a minute quantity 
of the oxide of copper. 

During the months of January and February I made several 
visits to the top of Vesuvius: I shall not particularize them 
all ; but shall mention only such as afforded me some new ob- 
servations. On the 26th of January, the lava was seen nearly 
white hot through a chasm near the place where it flowed from 
the mountain. I threw nitre upon it in large quantities through 
this chasm, in the presence of H. R. H. the Prince of Den- 
mark, whom I had the honour of accompanying in this ex- 
cursion to the mountain, and my friend the Cavaliere Monti- 
celli : there was no more increase of ignition than when the 
experiment was made on lava exposed to the free air. The 
appearance of the sublimations was now considerably changed : 
those near the aperture were coloured green and blue by salts 
of copper; but there was still a great quantity of muriate of 
iron. I have mentioned, that on the 5th the sublimate of the 
lava was pure chloride of sodium : in the sublimate of January 
6th, there were both sulphate of soda and indications of sul- 
phate of potassa. In the sublimates that I collected on the 
26th, the sulphate of soda was in much larger quantities, and 
there was much more of a salt of potassa. From the 5th of 
December to the 20th of February, the lava flowed in larger 
or smaller quantities, so that at night a stream of ignited mat- 

New Series. Vol. 4% No. 20. Aug. 1828. N ter 



90 Sir H. Davy on the Phenomena of Volcanoes, 

ter was always visible, more or less interrupted by cooled lava. 
It changed its direction according to the obstacles it met with ; 
and never, according to appearances, extended so much as a 
mile from its source. During the whole of this time the cra- 
ters, of which there were two, were in activity. The large 
crater threw up showers of ignited ashes and stones to a height 
apparently of from 200 to 500 feet ; and from a smaller crater, 
to the right of the large one on the side of Naples, steam arose 
with great violence. Whenever the crater could be approached 
it was found incrusted with saline incrustations ; and the walk to 
the edge of the small crater on the 6th of January was through 
a mass of loose saline matter, principally common salt coloured 
by muriate of iron, in which the foot sunk to some depth. It 
was easy, even at a great distance, to distinguish between the 
steam disengaged by one of the craters, and the earthy matter 
thrown up by the other. The steam appeared white in the 
day, and formed perfectly white clouds, which reflected the 
morning and evening light of the purest tints of red and orange. 
The earthy matter always appeared as a black smoke, forming 
black clouds ; and in the night it was highly luminous at the 
moment of the explosion. 

On the 20th of February, the small crater which had been 
disengaging steam and elastic matter, began to throw out 
showers of stones ; and both craters from the 20th to the 23rd 
were more than usually active. On the night of the 23rd, at 
half past 11 o'clock, being in my bed-room at Chiatimone, 
Naples, I heard the windows shake ; and going to the window, 
I saw ascending from Vesuvius a column of ignited matter to 
a height at least equal to that of the mountain from its base ; 
and the whole horizon was illuminated, notwithstanding the 
brightness of the moon, with direct volcanic light, and that 
reflected from the clouds above the column of ignited matter. 
Several eruptions of the same kind, but upon a smaller scale, 
followed at intervals of a minute and a half or two minutes ; 
but there were no more symptoms of earthquake, nor did I 
hear any noise. : On observing the lava, it appeared at its 
origin much broader and more vivid ; and it was evident that 
a fresh stream had broken out to the right of the former one. 
On the morning of the 24th I visited the mountain ; it was not 
possible to ascend to the top, which was covered with clouds, 
nor to examine the orifice from which the lava issued. The 
stream of lava near the place where it terminated was from 
50 to 100 feet broad. It had precisely the same appearances 
as the lava which had been so long running. I collected the 
saline matter condensed upon some of the masses of scoria 
which were carried along by the current and deposited on the 

edge 



Sir H. Davy on the Phenomena of Volcanoes. 91 

edge of the stream ; they proved to be the same in the nature 
of their constituent parts as those of the lava of the 26th of 
January, but with a larger proportion of sulphate of soda, and 
a smaller proportion of muriate of iron ; and I have no doubt 
that the dense white smoke which was emitted in immense 
columns by the lava during the whole of its course, was pro- 
duced by the same substances. 

I shall now mention the state of the volcano at some other 
periods. 

When I was at Naples in May 1814, the crater had the ap- 
pearance of an immense funnel, closed at the bottom, with 
many small apertures emitting steam ; and on the side towards 
Torre del Greco, there was a large aperture from which flame 
issued to a height of at least 60 yards, producing a most 
violent hissing noise. This phenomenon was constant during 
the three weeks I remained at Naples. It was impossible to 
approach sufficiently near the flame to ascertain the results of 
the combustion ; but a considerable quantity of steam ascended 
from it. When the wind blew the vapours upon us, there was 
a distinct smell both of sulphurous and muriatic acids. There 
was no indication of carbonaceous matter from the colour of 
the smoke ; nor was any deposited upon the yellow and white 
saline matter which surrounded the crater, and which I found 
to be principally sulphate and muriate of soda, and muriate of 
iron : in some specimens there was a considerable quantity of 
muriate of ammonia. 

In March 1815, the appearances presented by the crater 
were entirely different. There was no aperture in the crater ; 
it was often quiet for minutes together, and then burst out into 
explosions with considerable violence, sending fluid lava and 
ignited stones and ashes to a considerable height, many hun- 
dred feet, in the air. 

These eruptions were preceded by subterraneous thunder, 
which appeared to come from a great distance, and which 
sometimes lasted for a minute. During the four times that I 
was upon the crater in the month of March, I had at last learnt 
to estimate the violence of the eruption from the nature of the 
sound : loud and long continued subterraneous thunder indi- 
cated a considerable explosion. Before the eruption the cra- 
ter appeared perfectly tranquil ; and the bottom, apparently 
without an aperture, was covered with ashes. Soon, indistinct 
rumbling sounds were heard as if at a great distance; gra- 
dually the sound approached nearer, and was like the noise of 
artillery fired under our feet. The ashes then began to rise 
and to be thrown out with smoke from the bottom of the crater ; 
and lastly, the lava and ignited matter was ejected with a most 

N 2 violent 



92 Sir H. Davy on the Phenomena of Volcanoes, 

violent explosion. I need not say that when I was standing 
on the edge of the crater witnessing this phenomenon, the 
wind was blowing strongly from me : without this circumstance 
it would have been dangerous to have stood on the edge of 
the crater ; and whenever from the loudness of the thunder 
the eruption promised to be violent, I always ran as far as pos- 
sible from the seat of danger. 

As soon as the eruption had taken place, the ashes and 
stones which rolled down the crater seemed to fill up the aper- 
ture, so that it appeared as if the ignited and elastic matter 
were discharged laterally ; and the interior of the crater as- 
sumed the same appearance as before. 

I shall now offer some observations on the theory of these 
phenomena. It appears almost demonstrable that none of 
the chemical causes anciently assigned for volcanic fires can 
be true. Amongst these, the combustion of mineral coal is 
one of the most current ; but it seems wholly inadequate to 
account for the phenomena. However large a stratum of 
pit-coal, its combustion under the surface could never produce 
violent and extensive heat; for the production of carbonic 
acid gas, when there was no free circulation of air, must tend 
constantly to impede the process : and it is scarcely possible 
that carbonaceous matter, if such a cause existed, should not 
be found in the lava, and be disengaged with the saline or 
aqueous products from the bocca or craters. There are many 
instances in England of strata of mineral coal which have been 
long burning ; but the results have been merely baked clay 
and schists, and it has produced no result similar to lava. 

If the idea of Lemery were correct, that the action of sul- 
phur on iron may be a cause of volcanic fires, sulphate of iron 
ought to be the great product of the volcano ; which is known 
not to be the case ; and the heat produced by the action of 
sulphur on the common metals, is quite inadequate to account 
for the appearances. When it is considered that volcanic fires 
occur and intermit with all the phenomena that indicate in- 
tense chemical action, it seems not unreasonable to refer them 
to chemical causes. But for phenomena upon such a scale, 
an immense mass of matter must be in activity, and the pro- 
ducts of the volcano ought to give an idea of the nature of the 
substances primarily active. Now what are these products ? 
Mixtures of the earths in an oxidated and fused state, and in- 
tensely ignited ; water and saline substances, such as might be 
furnished by the sea and air, altered in such a manner as might 
be expected from the formation of fixed oxidated matter. But 
it may be said, if the oxidation of the metals of the earths be 
the causes of the phenomena, some of these substances ought 

occasionally 



Sir H. Davy on the Phenomena of Volcanoes. 93 

occasionally to be found in the lava, or the combustion ought 
to be increased at the moment the materials passed into the 
atmosphere. But the reply to this objection is, that it is evi- 
dent that the changes which occasion volcanic fires, take place 
in immense subterranean cavities ; and that the access of air 
to the acting substances occurs long before they reach the ex- 
terior surface. 

There is no question but that the ground under the solfa- 
terra is hollow, and there is scarcely any reason to doubt of a 
subterraneous communication between this crater and that of 
Vesuvius : whenever Vesuvius is in an active state, the sol- 
faterra is comparatively tranquil. I examined the bocca of the 
solfaterra on the 21st of February 1820, two days before the 
activity of Vesuvius was at its height: the columns of steam 
which usually arise in large quantities when Vesuvius is tran- 
quil, were now scarcely visible, and a piece of paper thrown 
into the aperture did not rise again ; so that there was every 
reason to suppose the existence of a descending current of air *. 
The subterraneous thunder heard at such great distances un- 
der Vesuvius, is almost a demonstration of the existence of 
great cavities below filled with aeriform matter : and the same 
excavations which in the active state of the volcano throw out 
during so great a length of time immense volumes of steam, 
must, there is every reason to believe, in its quiet state be- 
come filled with atmospheric airf. 

To what extent subterraneous cavities may exist even in 
common rocks, is shown in the limestone caverns of Carniola, 
some of which contain many hundred thousand cubical feet of 
air ; and in proportion as the depth of an excavation is greater, 
so is the air more fit for combustion. 

The same circumstance which would give alloys of the me- 
tals of the earths the power of producing volcanic phenomena, 
namely, their extreme facility of oxidation, must likewise pre- 
vent them from ever being found in a pure combustible state 
in the products of volcanic eruptions ; for before they reach 
the external surface, they must not only be exposed to the air 
in the subterranean cavities, but be propelled by steam ; which 
must possess, under the circumstances, at least the same faci- 
lity of oxidating them as air. Assuming the hypothesis of the 

* In 1814, in 1815, and in January 1819, when Vesuvius was compara- 
tively tranquil, I observed the solfaterra in a very active state, throwing up 
large quantities of steam and some sulphuretted hydrogen. 

f Vesuvius is a mountain admirably fitted, from its form and situation, for 
experiments on the effect of its attraction on the pendulum : and it would 
be easy in this way to determine the problem of its cavities. On Etna, the 
problem might be solved on a larger scale. 

existence 



94 Prof. Hare's Rationale on the Difficulty of separating 

existence of such alloys of the metals of the earths as may burn 
into lava in the interior, the whole phenomena may be easily 
explained from the action of the water of the sea and air on 
those metals ; nor is there any fact or any of the circumstances 
which I have mentioned in the preceding part of this paper, 
which cannot be easily explained according to that hypothesis. 
For almost all the volcanoes in the old world of considerable 
magnitude are near, or at no considerable distance from the 
sea : and if it be assumed that the first eruptions are produced 
by the action of sea water upon the metals of the earths, and 
that considerable cavities are left by the oxidated metals thrown 
out as lava, the results of their action are such as might be an- 
ticipated ; for after the first eruptions, the oxidations which 
produce the subsequent ones may take place in the caverns 
below the surface; and when the sea is distant, as in the vol- 
canoes of South America, they may be supplied with water 
from great subterranean lakes ; as Humboldt states that some 
of them throw up quantities of fish. 

On the hypothesis of a chemical cause for volcanic fires, and 
reasoning from known facts, there appears to me no other ade- 
quate source than the oxidation of the metals which form the 
bases of the earths and alkalies ; but it must not be denied that 
considerations derived from thermometrical experiments on 
the temperature of mines and of sources of hot water, render 
it probable that the interior of the globe possesses a very high 
temperature : and the hypothesis of the nucleus of the globe 
being composed of fluid matter, offers a still more simple so- 
lution of the phaenomena of volcanic fires than that which has 
been just developed. 

Whatever opinion may be ultimately formed or adopted on 
this subject, I hope that these inquiries on the actual products 
of a volcano in eruption will not be without interest for the 
Royal Society. 



XIV. Rationale of the Difficulty of separating Plane Surfaces 
by a Blast, in certain Cases. By R. Hare, M.D. Professor 
ofChemistiy in the University of Pennsylvania.* 

THE phenomenon above alluded to, is usually illustrated 
by means of two discs, into the centre of one of which, a 
tube is fastened, so that on blowing through the tube, the 
current is arrested by the other moveable disc. Under these 
circumstances, the moveable disc is not removed as would be 
naturally expected. Supposing the diameter of the discs to 

* Communicated by the Author. 

be 



Plane Surfaces by a Blast, in certain Cases, 95 

be to that of the orifice as 8 to 1, the area of the former to the 
latter must be as 64? to 1. Hence if the discs were to be se- 
parated (their surfaces remaining parallel) with a velocity as 
great as that of the blast, a column of air must meanwhile be 
interposed 64? times greater than that which would escape 
from the tube during the interim. Consequently, if all the air 
necessary to preserve the equilibrium be supplied from the 
tube, the discs must be separated with a velocity as much less 
than that of the blast, as the column, required between them, 
is greater than that yielded by the tube ; and yet the air can- 
not be supplied from any other source, unless a deficit of pres- 
sure be created between the discs, unfavourable to their se- 
paration. 

It follows, then, that under the circumstances in question, the 
discs cannot be made to move asunder with a velocity greater 
than l-64?th of that of the blast. Of course all the momentum 
of the aerial particles which constitute the current through 
the tube, will be expended on the moveable disc, and the thin 
ring of air which exists around the orifice between the discs ; 
and since the moveable disc can only move with l-64th of the 
velocity of the blast, the ring of air in the interstice must ex- 
perience nearly all the momentum of the jet, and must be 
driven outwards ; the blast following it in various currents ra- 
diating from the common centre of the tube and discs. The 
effect of such currents in producing an afflux of the adjoining 
portions of any fluid in which they may be excited, is well 
known, having been successfully illustrated by Venturi. (See 
Nicholson's Journal, quarto series, vol. ii. p. 172.) Accordingly 
the afflux of air towards the discs counteracts the small velo- 
city which the blast would communicate, and thus prevents 
their separation, and may even cause them to approach each 
other, if previously situated a small distance apart. 

This rationale commences with the assumption, that the 
discs will remain nearly parallel. That there cannot be much 
deviation from parallelism must be evident ; since any obliquity 
will make the opening greater on one side than on the other ; 
and the jet proceeding with most force towards the widest 
opening, will increase the afflux of air upon the outer surface 
of the moveable disc in the part where the current is strongest, 
and thus correct the obliquity. 



XV. Chemical 



,[ * ] 

XV. Chemical Examination of the Oxides of Manganese. By 
Edwaud Turner, M.D. F.R.S. Ed. Prof essor of Chemistry 
in the University of London, and Fellow of the Royal College 
of Physicians of Edinburgh. 

[Concluded from p. 35.] 

Part II. 

On the Composition of the Ores of Manganese described by Mr. 
Haidinger. 

Method of Analysis. — pURE fragments of the ores were 
* carefully selected, recjuced to fine 
powder in a mortar of agate, and washed with distilled water. 
Some of the ores yielded nothing to the action of water; but 
from some of them, especially from those of Ihlefeld, minute 
quantities of the muriate and sulphate of lime, and sometimes 
of soda, were separated by the action of water. It is the ac- 
cidental presence of the muriates which gives rise to the dis- 
engagement of chlorine when sulphuric acid is added to some 
of the native oxides of manganese, and which induced Mr. 
Macmullin to regard chloric acid as a constituent of these ores. 
For the correction of this error we are indebted to Mr. Richard 
Phillips*, with whose observation my own experiments cor- 
respond ; — none of the native oxides yield a trace of chlorine 
on the addition of sulphuric acid, provided the muriates have 
been previously removed by washing. 

The ores, before being submitted to analysis, were dried at 
212° F., by which means they were brought to the same degree 
of dryness which they possessed before being washed. The 
water naturally contained in them was ascertained in every 
instance by heating a known quantity of the ore to redness, 
and collecting the water in a tube filled with fragments of the 
chloride of calcium. 

The quantity of oxygen was in most cases ascertained both 
by bringing the ore to the state of red oxide by exposure to a 
white heat, and by converting it into the protoxide by means 
of heat and hydrogen gas. When performed with the pre- 
cautions stated in the first part of this communication, either 
of these methods may be relied on with confidence; but the 
first is more convenient in general practice, because it requires 
less time and a more simple apparatus. The latter is some- 
times very troublesome, owing to the difficulty with which some 
of the ores of manganese, the native peroxide for example, are 

* Phil. Mag. and Annals, vol. i. p. 313. 

reduced 



Dr. Turner's Examination of the Oxides of Manganese, 97 

reduced by hydrogen to the state of pure protoxide. I have 
in no instance estimated the quantity of oxygen by means of 
the deutoxide, the formation of this compound being in my 
opinion too uncertain to admit of any analytic process being 
founded upon it. 

In searching for the presence of foreign matters I have em- 
ployed the following processes. The water which was expelled 
from the ores by heat, was examined with test paper, but was 
always found quite free from alkaline or acid reaction. The 
absence of carbonates was ascertained by the entire want of 
effervescence on the addition of dilute nitric acid. Strong sul- 
phuric acid did not cause the evolution of chlorine or any acid 
fumes. 

On dissolving the ores in muriatic acid and evaporating the 
solution to perfect dryness, the residue, with the exception of 
a little siliceous matter and red oxide of manganese proceeding 
from slight decomposition of the chloride, was always com- 
pletely redissolved by water. This circumstance demonstrates 
the absence of phosphoric and arsenic acids, which, if present, 
would have been left as the insoluble phosphate or arseniate 
of manganese. By well known methods I satisfied myself of 
the absence of sulphuric acid, alumina, and magnesia. In se- 
veral of the ores the oxalate of ammonia detected a trace of 
lime. It is remarkable that every species, with one exception, 
contains baryta. In most of them, indeed, it is present only 
as an impurity ; but in two of the ores, the uncleavable man- 
ganese-ore or black hematite, and the manganese oxide noir 
barytifere of Haiiy, it is an essential ingredient of the mixture. 
In those species in which this earth exists as an impurity, it is 
not united with the sulphuric or carbonic acid ; but is most 
probably combined with the peroxide of manganese. 

From the frequency with which iron has been found accom- 
panying the ores of manganese, I was led to expect its pre- 
sence, and employed the ferrocyanate of potash and hydrosul- 
phuret of ammonia as re-agents for its detection. The muriatic 
solution of the different species yielded a white precipitate with 
the ferrocyanate of potash, and the characteristic flesh-coloured 
sulphuret of manganese with the hydrosulphuret of ammonia. 
It hence follows that all the ores submitted to analysis, even the 
uncleavable manganese-ore, which has been placed among the 
ores of iron, are perfectly free from iron, as well as from cop- 
per, lead, and similar metallic substances. 

Analysis of Manganite or the Prismatoidal Manganese-ore. 
— This ore, even when selected with the greatest care, yields 
to distilled water traces of the muriates and sulphates of lime 
and soda. It dissolves without residue in muriatic acid, and 

New Series. Vol. 4. No. 20. Aug. 1 828. O is 



98 Dr. Turner's Chemical Examination 

is free from siliceous earth, lime, baryta, and every other im- 
purity. It is the purest native oxide of manganese which has 
fallen under my notice. Its powder has a uniform brown tint, 
and I have been unable to observe in it any tendency to pass 
into the peroxide by absorbing oxygen from the air. After 
exposure to the air for six months, during which it was fre- 
quently moistened with distilled water, it underwent no change 
of weight. Cold sulphuric acid acts very feebly on this oxide. 
M. Gmelin* of Heidelberg states that it is not dissolved at all 
by this acid in the cold, and I was at first of the same opinion : 
but by employing a considerable quantity of the oxide, and 
agitating the mixture frequently, the acid does acquire a red 
tint in the course of two or three days. In this respect man- 
ganite agrees with the peroxide ; but differs from all the other 
species, which communicate a red colour to cold sulphuric 
acid with much greater facility. 

When manganite is heated to redness it gives out 10*10 per 
cent of water ; and the total loss from exposure to a white heat 
is 1 3* 1 5 per cent. Deducting from the last number the amount 
of water, 3*05 remain as the loss in oxygen. The result of 
this analysis is therefore, 

Red oxide 86-85 

Oxygen 3*05 

Water 10-10 

100-00 
According to this analysis, manganite contains an oxide of 
manganese, 89*9 parts of which yield 3-05 of oxygen, on being 
converted into the red oxide. An equal quantity of pure deut- 
oxide, in undergoing a similar change, should lose 2*997 of 
oxygen. 

Exposed to a strong red heat and a current of hydrogen 
gas, 100 parts of manganite lost 19*09 parts in one experi- 
ment, and 19*07 in another. The mean is 19*08, and sub- 
tracting 10*10 as water, 8*98 remain as oxygen. According 
to this analysis the manganite is composed of 

Protoxide 80*92 

Oxygen 8*98 

Water 10-10 

100-00 
Now as 80-92 : 8'98 : : 36 : 3-995. 

* I regret that I have been unable to obtain a sight of that volume of 
the Zeitschrift der Mineralogie, which contains M. Gmelin's paper on the 
composition of the oxides of manganese. My knowledge of his labours is 
solely derived from M. Leonhard's Handbuch der Orykiognosie. 

From 



of the Oxides of Manganese. 99 

From the result of both analyses it is apparent that man- 
ganite, in relation to manganese and oxygen, is a deutoxide. 

Also as 89*90 : 10-10 :: 40 : 4-494.. 
The fourth number is so near 4*5, half an equivalent of water, 
that we may safely regard manganite as a compound of 80 
parts or two equivalents of the deutoxide of manganese, and 
9 parts or one equivalent of water. 

The material for the preceding analysis was taken from a 
very fine crystallized specimen from Ihlefeld. The result of 
Gmelin's analysis of the same variety is as follows : — Red oxide 
87*1, oxygen 3*4, water 9*5. The water is here certainly un- 
derrated. 

The grey oxide from Undenaes in West Gothland, analysed 
by Arfwedson, is a similar compound. 

Analysis of the Brachytypous Manganese-ore or Braunite, — 
The colour of this ore, both in mass and in powder, is nearly 
black. With sulphuric acid it yields no distinct odour of 
chlorine. It dissolves in muriatic acid, leaving a trace of si- 
liceous matter. The solution gives a precipitate of sulphate 
of baryta with sulphuric acid, but does not contain any other 
impurity. Of all the native oxides this is the most easily re- 
duced to the state of protoxide by the action of hydrogen gas. 
The material for analysis formed part of a specimen from 
Elgersburg. 

As a mean of two closely corresponding experiments, this 
oxide contains 0*949 per cent of water. 

To ascertain the quantity of oxygen, 16*634 grains were 
exposed for half an hour to the action of hydrogen gas at a 
red heat. The residue weighed 14-837 grains, and had the 
light green tint of the protoxide. The total loss was 1*797 
grains, or 10-80 percent; and subtracting 0*949 for water, 
there remains 9*851 per cent as the loss in oxygen. 

The baryta was precipitated by sulphuric acid from a solu- 
tion in muriatic acid of 42*09 grains of the mineral. The pre- 
cipitate after being heated to redness amounted to 1*44 grains, 
equivalent to 0*951 of a grain or 2*26 per cent of pure baryta. 
According to this analysis, 100 parts of the ore contain 

Protoxide 86*94 

Oxygen 9*851 

Water 0*949 

Baryta 2*260 

Silica a trace. 



100*000 
Now 86*94 : 9*851 : : 36 : 4*079 ; and as the presence of wa- 
ter and baryta, from the small quantity of these substances, 

O 2 must 



100 Dr. Turner's Chemical Examination 

must be regarded rather as accidental than essential to the 
mixture, it follows that braunite is an anhydrous deutoxide of 
manganese. I apprehend the baryta must be in combination 
with deutoxide of manganese ; since, were it united with per- 
oxide, the loss in oxygen would exceed the quantity above 
stated. 

I am not acquainted with any analysis of this mineral by 
other chemists. 

Analysis of the Pyramidal Manganese-ore or Hausmannite. — 
Hausmannite, before being washed, yields a faint odour of 
chlorine by the action of sulphuric acid. When heated to 
redness it gives off 0*435 per cent of water ; and at a white 
heat the loss is only 0*65 per cent, indicating 0*2 1 5 of oxygen. 
When dissolved in muriatic acid, a small quantity of silica is 
left, amounting to 0*337 per cent ; and on adding sulphuric 
acid to the solution, a little sulphate of baryta subsides, indi- 
cating 0*11 1 per cent of the pure earth. Hausmannite is ac- 
cordingly resolved by this analysis into 

Red oxide 98*098 

Oxygen 0*21 5 

Water 0*435 

Baryta 0*111 

Silica 0*337 



100*000 
This oxide is manifestly an anhydrous red oxide of manga- 
nese. The small quantity of oxygen lost at a white heat is 
probably owing to the admixture of a little deutoxide or per- 
oxide, combined with the baryta. 

From some preliminary experiments on hausmannite, M. 
Gmelin of Heidelberg * inferred that it is a pretty pure red 
oxide, an inference which entirely agrees with the result of 
the preceding analysis. This is the only chemical examination 
of hausmannite by other chemists, which I have met with. 
The material for my analysis was part of a specimen from 
Ihlefeld, for which I am indebted to the kindness of Professor 
Stromeyer. 

Analysis of Pyrolusite, or the Prismatic Manganese-ore, — 
The following analysis was made with a compact columnar 
variety from Elgersburg, which has a specific gravity of 4*94, 
and the individuals of which have a parallel direction. With 
sulphuric acid it does not yield a trace of chlorine; and 
the only impurities which I could discover in it are silica and 
baryta, the former amounting to 0*513, and the latter to 0*532 
per cent. 

* Lconhard's Handbuch der Orylrtognosia. 

The 



of the Oxides of Manganese. 101 

The quantity of water was determined as usual by means of 
the chloride of calcium, and amounted to 1*12 per cent. * 

On exposing 23*746 grains of this oxide to a white heat, 
the loss proved to be 3*064 grains or 12*90 per cent. Sub- 
tracting 1*12 for water, there remain 11*78 as the loss of 
oxygen. 

Accordingly, 100 parts of the pyrolusite were resolved into 

Red oxide 84*055 

Oxygen 11*78 

Water 1*12 

Baryta 0*532 

Silica 0*513 

100*000 
Now, omitting the water, baryta, and silica as accidental im- 
purities, the remaining 97*835 parts lose 11*78 parts, or 12*04 
per cent of oxygen in being converted into the red oxide. On 
the supposition that pyrolusite is composed of one equivalent 
of manganese and two equivalents of oxygen, it should lose in 
passing into the state of red oxide exactly 12*122 per cent of 
oxygen, a quantity which corresponds closely with the result 
of analysis. It is therefore an anhydrous peroxide of man- 
ganese. 

I have analysed another columnar variety of pyrolusite, 
which has a density of 4*819, and of which the individuals ra- 
diate from a common centre. I brought it with me from Ger- 
many, and believed it to be from Ihlefeld, as the ticket indi- 
cated ; but Mr. Haidinger, after carefully inspecting several 
large cabinets in Germany, has been unable to discover any 
similar specimen which is known to have been found in that 
place. Its locality therefore is doubtful. 

This variety is less pure than the foregoing. Before being 
washed, it yields chlorine on the addition of sulphuric acid ; 
and after the muriates have been removed by distilled water, 
the neutral solution in muriatic acid gives traces of lime with 
oxalate of potash. It contains silica and baryta nearly in the 
same proportion as the first variety. 

The following is the result of my analysis : 

Red oxide 85*617 

Oxygen 1 1*599 

Water 1*566 

Silica 0*553 

Baryta 0*665 

Lime a trace. 

100*000 

Subtracting 



102 Dr. Turner's Chemical Examination 

Subtracting 2*784 as impurities, there remain 97*214 parts, 
which lose 11*599, or 11*931 per cent, of oxygen in being 
converted into the red oxide. It is therefore an anhydrous 
peroxide, most probably containing an admixture of some 
other oxide. 

Analysis of Psilomelane, or the Uncleavable Manganese-ore. 
— Tliis mineral when reduced to powder has a brownish-black 
colour. With sulphuric acid it does not emit any odour of 
chlorine. It dissolves completely in muriatic acid, excepting 
a small quantity of silica which amounts to 0*26 per cent ; and 
the only substances which I could detect in the solution are 
baryta and the oxide of manganese. Though this ore has been 
placed by mineralogists among the oxides of iron, under the 
names of Black Hematite and Black Iron-ore, pure fragments 
of it do not contain a trace of that metal. 

When heated to redness psilomelane gives out 6*216 per 
cent of water. The diminution in weight occasioned by ex- 
posure to a white heat is 13*58 per cent; and on subtracting 
6*216 for water, there remains 7*364 as the loss in oxygen. 

To ascertain the quantity of baryta 30*028 grains of the mi- 
neral were dissolved in muriatic acid, and the baryta precipi- 
tated by means of the sulphate of soda, a considerable excess 
of muriatic acid being allowed to remain in the liquid, to pre- 
vent any manganese from adhering to the precipitate. The 
sulphate of baryta, after exposure to a red heat, amounted to 
7*434 grains, equivalent, according to the atomic numbers of 
Dr. Thomson, to 4*914 grains, or 16*365 per cent of pure 
baryta. 

According to this analysis, 100 parts of psilomelane have 
yielded of 

Red oxide 69*795 

Oxygen 7*364 

Baryta 16*365 

Silica 0*260 

Water 6*216 



100*000 
The precise atomic constitution of psilomelane is not made 
apparent by this analysis ; and, indeed, the result is of such a 
nature as to leave no doubt of this mineral containing more 
than one oxide of manganese. For it follows, from the quan- 
tity of oxygen expelled by heat, that a considerable part of 
the manganese must be in the form of peroxide; but it is 
equally clear that the whole of it cannot be in that state, be- 
cause 69*795 parts of red oxide require 9*627 instead of 7*364 
parts of oxygen to constitute the peroxide. On perceiving 

this 



of the Oxides of Manganese. 103 

this deficiency of oxygen, I at first suspected that the baryta 
might prevent the usual quantity of oxygen from being expelled 
from the peroxide by heat. Accordingly I ascertained the 
quantity of pure red oxide by the way ofprecipitation ; but its 
amount corresponded closely with the number already stated. 
Psilomelane must therefore, I conceive, be a mixed mineral. 
I was at first disposed to regard it as a compound of baryta 
and peroxide of manganese, accidentally containing an ad- 
mixture of some other oxide in a lower stage of oxidation ; but 
the fact noticed by Mr. Haidinger of psilomelane being fre- 
quently and intimately associated with pyrolusite in the mi- 
neral kingdom, appears to justify the inference, that the un- 
cleavable manganese-ore consists essentially of some com- 
pound, in proportions not yet ascertained, of baryta and the 
deutoxide of manganese, and that pyrolusite is the accidental 
ingredient. The propriety of this view is further shown by 
an analysis of the following ore from Romaneche, a mineral 
which is analogous to psilomelane in the proportion of its in- 
gredients, and in which an admixture of pyrolusite may be 
detected by the eye. 

Analysis of the Manganese oxide noir Barytifere^om Ro- 
maneche. — The observations of Mr. Haidinger leave no doubt 
of this ore being a mixed mineral ; and according to my ana- 
lysis it is very analogous to psilomelane. The specific gravity 
of some of the purest fragments which I could select, is 4*365; 
and the density of psilomelane, according to Mr. Haidinger, 
is 4*14)5. The colour of both minerals is similar. 

The black oxide of Romaneche yields a very faint odour of 
chlorine with sulphuric acid. When heated to redness it gives 
out 4*13 per cent of water. At a white heat it loses 1 1 *39 per 
cent; and after subtracting 4*13 for water, there remain 7*26 
as the loss in oxygen. 

In order to ascertain the quantity of baryta, 32*13 grains 
were dissolved in muriatic acid ; and after separating a small 
portion of silica, which amounted to 0*953 per cent, I preci- 
pitated the baryta by means of the sulphate of soda. The in- 
soluble sulphate, after exposure to a red heat, weighed 8*113 
grains, equivalent to 5*363 grains, or 16*69 per cent of pure 
baryta. J 00 parts of the oxide are accordingly resolved into 

Red oxide 70*967 

Oxygen 7*260 

Baryta 16*690 

Silica 0*953 

Water 4*130 

100*000 

This 



104? Prof. Gauss on the Representation of the Parts 

This mineral was analysed some years ago by Vauquelin 
and Dolomieu ; but the numbers which they have mentioned, 
owing to the insufficient mode of analysis employed at that 
time, are not entitled to any confidence. — [Journal des Mines 
ix. 778.) 

XVI. General Solution of the Problem : to represent the Parts 
of a given Surface on another given Surface, so that the 
smallest Parts of the Representation shall be similar to the cor- 
responding Parts of the Surface represented. By C. F. Gauss. 
Answer to the Prize Question proposed by the Royal Society 
of Sciences at Copenhagen*. 

Ab his via sternitur ad majora. 

r T , HE author of this paper believes that he must consider 
-*- the repeated selection by the Royal Society of the question 
which forms the subjects of it, as a proof of the importance 
which the Royal Society attaches to it ; and has thereby been 
induced to submit a solution found by him some consider- 
able time since, as the lateness of the time at which he was in- 
formed of the prize question would otherwise have prevented 
him from sending an answer. He regrets that the latter cir- 
cumstance has obliged him to limit his inquiry to the essen- 
tial part only, besides hinting some obvious applications to 
the projection of maps and the higher branches of geodetics. 
Had it not been for the near approach of the term fixed by 
the Society, he would have followed up several inquiries, and 
have detailed numerous applications of the subject to geo- 
detical operations ; all which he must now reserve to himself 
for another moment and another place. 
December 1822. 

1. The nature of a curve surface is determined by an equa- 
tion between the coordinates belonging to every point of the 
same x, y, z. In consequence of this equation, every one of 
these three variable quantities may be considered as a function 
of the two others. It is still more general to introduce two 
new variable quantities t, u, and to represent each of the quan- 
tities x, y, z as a function of t and u, by which at least generally 
speaking, determinate values of t and u always belong to every 
determinate point of the surface, and vice versa. 

2. Let X, Y, Z, T, U have the same signification for a se- 
cond surface, which x, y, z, t, u had in reference to the first. 

3. To represent the former surface on the second means to 

* From Prof. Schumacher's Astronomische Abhandlungen, No. 3. 

establish 



of a given Surface on another given Surface. 1 05 

establish a law by which a determinate point of the second 
surface is to correspond to every point of the first. This will 
have been effected if T and U have been made equal to two 
functions of t and u. These functions will cease to be arbi- 
trary as soon as they are required to satisfy certain conditions. 
As X, Y, Z next become likewise functions of t and u 9 these 
functions must, therefore, besides satisfying the conditions re- 
quired by the nature of the second surface, also fulfill those of 
the representation. 

The problem of the Royal Society of Sciences prescribes 
that the representation shall be similar to the object repre- 
sented in the smallest parts. It is, therefore, first required to 
find an analytical expression for this condition. Let us sup- 
pose that the following equations are the result of the diffe- 
rentiation of the functions of t and u expressing the values of 
x,y,z, X,Y,Z. 

dx = adt + aJdu 

dy = bdt 4- b'du 

dz = c dt + c'du 

dX= Adt+ Mdu 

dY = Bdt + B'du 

dZ = Cdt + C'du 
The condition prescribed requires first that all infinitely small 
lines proceeding from one point of the first surface and situate 
in it, shall be proportionate to the corresponding lines on the 
second surface ; and next, that the former shall form between 
them the same angles as the latter. 

Such a linear element on the first surface has this expression 
V(ja z + b 2 + c 2 )dt 2 + 2{aa' + bV + cd)dtdu + (a' 2 + bl 2 -{-c' 2 )du 2 ') 
and the corresponding one on the second surface is 

\f((A 2 +B 2 +C 2 )dt 2 +2( < AA' + BB' + CO)dtdu+(A' 2 +B'* 

+ C' 2 )^ 9 ). 
If both are to be in a certain ratio independent of dt and du 9 
the three quantities 

a 2 + b 2 + c 2 i aa' + bb' + cc\ a' 2 + b' 2 + d 2 
must evidently be respectively proportional to the three quan- 
tities A2 + B 2 + Q* A A , + BB , + CC , ? A /2 + B' 9 + C' 2 . 

If we suppose that the values t, u and t + U, u + §u corre- 
spond to the extreme points of a second element on the first 
surface, the cosine of the angle formed between the two ele- 
ments on that surface, will be 

(adt+a f duXah+a^u)^(bdt^b'duXb2t^^u)-^(cdt-\-c'duXch-{-c'iu) 

// [(adt+adu)*+(bdt+b'du)*+{cdt+c'duy~j • [(aST+a'l M )H(*^-|-6'5M) 2 +(c^-|-c'Su)-' n 

New Series, Vol. 4. No. 20. Aug. 1828. P and 



106 Prof. Gauss on the Bepresentation of the Parts 

and we shall obtain an exactly similar expression for the co- 
sine of the corresponding angle on the second surface by 
changing a, b, c 9 a', #, d into A, B, C, A', B', Q. The two 
expressions become clearly equal if the above-mentioned pro- 
portionality takes place, and the second condition is already 
comprehended in the first, as a little reflection will easily 
show. 

The analytical expression of the condition of our problem 
is, therefore, this: 

A«+B«-}-0 __ AA'+B.B'+C.C __ AA'+B'B'+C'G 
a*+b*+c* aa'+bb'+ cc ><2_j_#«-|- c 'a * 

Let the value of these equal quantities, which must be a finite 
function of t and u, be = m\ The quantity m is therefore 
the index of the ratio in which linear quantities on the first 
surface are increased or diminished in their representation 
on the second surface (according as m is greater or smaller 
than 1). This ratio will, generally speaking, be different in 
different places : in the particular case in which m is constant, 
there will be a perfect similarity also in the finite parts ; and if 
m is besides = 1 , there will be a perfect equality, and the one 
surface may be developed on the other. Putting for brevity 

(a 2 + b z + c 2 )df + 2(aa , + bb l +cc , )dt.du + (a! 2 + b n + d 2 )du 2 =a) 

we remark that the differential equation co = admits of two 
integrations. Representing the trinomial oo as the product of 
two factors linear with respect to d t and d u, either of the two 
may be = 0, which will give two different integrations. One 
of the integrations will be derived from the equation : = 

(a 2 + b z +c*)dt+{aa' + bb' + cJ+i\/[(a*+b*+c i )(a , *+b , * + 
(?*)—{aa! + bV +cc**)]}du 

(where i is written for brevity instead of */ — 1, for it will be 
easily seen that the irrational part of the expression must be- 
come imaginary), the other integration will be the result of 
a similar equation, which will be obtained by putting — i in 
place of i in the former. If the integral of the first equation 

bethis p + iq= const. 

where p and q denote real functions of t and u, the other in- 
tegral will be p _ iq _ const# 

It follows from this, that (dp + idq) (dp— idq) or dp* + dq* 
must be a factor of co, or that 

w = n (dp* + dq 9 ) 
where n is a finite function of t and u. 

Let us now denote by ft the trinomial into which dX*+ 



of a given Surface on another given Surface. 107 

dY* + dZ* will be converted by substituting for dX, d Y, and 
d Z their values expressed by T, U, d T and d U ; and let us 
assume that in a similar manner, as before, the two integrals of 
the equation i2=0 are as follow : 

P -f i Q = const. ; P— iQ = const, and 

SI = N. (rfP + rfQ 9 ) where P, Q, N denote real func- 
tions of T and U. 

These integrations may evidently be effected (without taking 
into consideration the general difficulties of integrating) be- 
fore the solution of our principal problem. 

Now, if for T, U such functions of t and u are substituted 
as will fulfill the condition of our principal problem, ft will be 
changed into m 2 co, and we shall have 

(rfP + id Q) . (dP - idQ) m*n 

(dp +idq) • (dp — idq) N 

But it will be easily seen that the numerator in the first part 
of this equation cannot be divisible by the denominator, ex- 
cept if either 

dP + idQ is divisible by dp + idq, and d¥—idQ by dp—idq 9 

or, 
dF + idQ is divisible by dp*~idq, and dP— idQ by dp-\-idq. 

In the former case dV + idQ will therefore vanish if dp -f 
idq = 0, or P + * Q will be constant if p + iq is supposed to 
be constant; that is to say, V + iQ will be a function of p-\-iq 
only, and in the same manner P — i Q will be a function of p — i q. 
In the latter case P + zQ will be a function of p— iq, and 
P— z'Q a function of p + iq. It is easy to perceive that the 
reverse of these positions likewise holds good, or that if for 
P + fQandP — iQ functions o$ p + iq or p—iq (either re- 
spectively or inversely) are assumed the divisibility of SI by co, 
and consequently the above required proportionality will take 
place. 

It will easily be conceived that if, for example, we suppose 

P + **Q =f(p + iq), P-/Q =f(pe-iq) 
the nature of the function f is already given by that off. For 
if among the constant quantities which it involves, there are 
none but real quantities, the function f 1 must be identical with 
f; in order that real values of P and Q may correspond to 
real values of p and q : in the contrary case, f will only be 
distinguished fromy by having in the imaginary quantities 
which f involves — i instead of -fz*. 

We have next, P = \f{ p + iq) + if'( p — iq) 

iQ = if(p+iq)-U\p- i 9)> 

or, which is the same, as the function f is assumed quite ar- 

P 2 bitrarily 



108 Prof. Gauss on the Representation of the Parts 

bitrarily (involving at pleasure constant imaginary quantities), 
P is equal to the real, and z'Q (or — *Q in the second solution) 
equal to the imaginary part o?f(p + iq) 9 and by elimination 
T and U will be represented as functions of t and u. Thus 
the proposed problem is solved quite generally and com- 
pletely. 

6. If we represent any determinate function of p + iq by 
p* + * 4 (where $ and q' are real functions ofp and q\ it will 
be easily seen that likewise the equations 

p ] + iq* = const, and p ] — iq 1 = const, 
will represent the integrals of the differential equation w = ; 
indeed, these equations will respectively agree with the above 

p + iq = const, and/?— iq = const. 
In like manner the integrals of the differential equation /2=0, 
viz. P' + *Q' = const, and F— iQ = const, 

will agree with the above, 

P + /Q = const, and P — iQ = const, 
if P'-f I Qf represents any determinate function of P + z'Q 
(while F and Q' are real functions of P and Q). Hence it is 
clear that in the general solution of our problem which we 
have given in the preceding article, p' and q' may be substi- 
tuted for p and q, and P' and Q' for P and Q. Although this 
change does not add to the generality of the solution, yet in 
practice one form may be more applicable to one, and another 
to another purpose. 

7. If the functions arising from the differentiation of the 
arbitrary function/* and/ 7 are denoted respectively by <p and 
$', so that d .f'v = $ v . d v and d .f ' v = <p'v .dv.we shall have 
in conformity with our general solution 

therefore, *£ = *(p + iq).*(p-iq). 

The scale of linear dimensions is determined by 

8. We shall now illustrate our general solution by some 
examples by which the manner of applying it, as well as the 
nature of some circumstances which may come into considera- 
tion, may be best explained. 

Let the two surfaces be in the first place planes, in which 
case we may put 

x =■ t y y = w, z = 
X = T, Y = U, Z = 0. 

The 



of a given Surface on another given Surface* 109 

The differential equation cg = dP + du 9 = gives these two 
integrals 

t + iu — const, t — iu = const. 

and in like manner the two integrals of the equation ft = 
dT+rfU 2 = 0, are the following T+fU = const., T-/U = 
const. The two general solutions of the problem are ac- 
cordingly 

I. T + iU=f(t + iu), T-i\J=f'(t-zu) 

II. T + *U =f(t-iu\ T-*U =/'(*+*?/). 

This result may be thus expressed : f signifying an arbitrary 
function, the real part off(x + iy) is to be taken for x, and the 
imaginary part divided by i for y or for — y. 

If the functional characteristics <p, <p' are taken in the same 
signification which they have in article 7, and if we put 

$(x+iy) =£ + *>j, tf{x— iy) = $-1* 

where £ and >j will be clearly real functions of x and y, we 

have by the first solution 

dX+idY = (g + iyi)(dx+idy) 
dX — idY = (£—/»}) (dx—idy) 

and consequently, dX = £dx—r\dy 
dY = i\dx-\-%dy 
If we now put £ = <r . cos,/ , 19 = <r . sin,/ 
dx = ds. cos g, dij=:ds.smg 
dX=zdS.cosG, dY =zdS.sinG, 
so that ds is a linear element in the first plane, g its inclina- 
tion to the line of abscissae, d S the corresponding linear ele- 
ment in the second plane, and G its inclination to the line of 
abscissae, the above equations give 

d S . cos G = o- . d s . cos (g -\-j) 
d S . sin G = <r ds sin {g+j) 9 and consequently, 
if we consider cr as positive, as we may do 
dS = a-.ds , G = g+j. 
We see, therefore (in conformity to article 7), that <r is the 
index of the ratio of increase of the element ds in the repre- 
sentation d s, and is, as it ought to be, independent of g ; and 
in the same way the angle,/ being independent of g, proves 
that all linear elements of the first plane proceeding from one 
point are represented by elements in the second plane which 
form to each other, and, as we may add, in the same direction, 
the same angles. 

If we now choose for/ a linear function, so that/p = A + 
B v where the constant coefficients are of the form A=a + b. i y 

B = 



110 Prof. Gauss on the Representation of the Parts 

Bsc+ei, we shall have ^» = Bac+e/, therefore tr =c 

V{c*+e*)> j = arc tang -^-. 

The ratio of increase or the scale is consequently constant 
throughout, and the whole representation similar to the surface 
represented. For every other function f 9 it may be easily 
proved that the scale cannot be constant, and that the simila- 
rity can only take place in the smallest part. If the places 
are given wnich are to correspond in the representation to a 
determinate number of given points of the first plane, we may 
easily determine by the common method of interpolation the 
simplest algebraical function f, which will fulfill those condi- 
tions. If we denote the values of x + iy for the given points 
by a, b 9 c, &C. and the corresponding values of X + i Y by A, 
B, C, &c* then it will be necessary to put 

* (a— b)(a— c)... (6— o)(6— c)... ' (c— a){c— b)... 

which is an algebraical function of v of a degree one unity 
lower than the number of given points. For two points, where 
the function becomes linear, a perfect resemblance will conse- 
quently take place. 

An useful application may be made of this in geodetics, for 
converting a map founded on moderately good measurements, 
which in its minute detail is good, but on the whole somewhat 
distorted, into a better one, if the correct position of a number 
of points is known. 

Going through the second solution in the same manner, it 
will be found that the only difference is, that the similarity is a 
reversed one ; that all elements form indeed with each other 
the same angles as in the original, but in a contrary direction, 
so that that which is to the right in the one, is to the left in the 
other. But this difference is not an essential one, and vanishes 
if the side of the plane which was first considered as the upper 
one is made the lower one. This latter remark may be always 
applied whenever one of the surfaces is a plane ; and we shall 
confine ourselves in the following examples of this kind to the 
first solution. 

9. Let us now consider (as a second example) the repre- 
sentation of the surface of a perpendicular cone in a plane. As 
the equation of the former, we take 

where we put x = K t . cos u, y = K t . sin #, z = t, and as 
before, X = T, Y = U, Z = 0. 

The 



of a given Surface on another given Surface. 1 1 L 

The differential equation, 

m = (K 2 + 1) dt 2 + %}t*du* = 0, gives the two integrals, 

log t ± i*J R77 • u = const. 
We have, accordingly, the solution 

X + *Y -f(logt + i s /~ r uy 

X-iY=f(\ogt + iJ 1 ^ l .u); 

that is to say,/ denoting an arbitrary function, X is to be the 

real part of/ (log t + i *J R tn, and Y the imaginary 

part, leaving out the factor u 

Let an exponential quantity be taken for/ or let/w = he v 
where ^ is constant and e the base of the hyperbolical loga- 
rithms, and the most simple representation will be 

X = ht. cos s/-KT+i- u - Y = ht.sm*J g~| .a. 
The application of the formulae of article 7, gives in this case 

rc = (K 2 +l)* 2 N=l 
and $ being = $ ! v = h /, 
* (logZ + zV^ . «) . $' (log t-ij^.u) = tf « 

consequently m = ■ - , and therefore constant. If now, 

besides, h is made = \/(K 2 + 1), the representation becomes a 
perfect development. 

10. Let it next be required; to represent in a plane the 
surface of a sphere whose radius = a. We put here 

x = a . cos t . sin #, ^ = « . sin £ . sin u 9 
Z = a . cos w, by which we obtain 
co = dtsmu? dt 2 + a 2 du% The differential equation 
co = gives consequently 

d 2 :p t . -^- = 0, and its integration 

t ± i log . cotang ,\u =; const. 
If we denote therefore again by f an arbitrary function, 
X is to be put equal to the real, and i Y to the imaginary part 
of f{t + i log cotang \ u). We shall adduce some parti- 
cular cases of this general solution. If we choose for / a 
linear function by putting fv ;=( kv, we shall have X = kt 
Y = k log cotang \ iu 

This 



1 12 Prof. Gauss on the Representation of the Parts, fyc. 

This agrees evidently when applied to the earth with Mer- 
cator's projection, if we make t the geographical longitude, 
and 90°— a the latitude. For the scale of linear dimensions 

k 

the formulae of article 7 give m = — : — . 

° a sin u 

If we assume for f an imaginary exponential function, and 
in the first place the simplest of all, fv = k e lv , we have 

/(/ + l log cotang * u) = £e logtang * M + i < = 
£ tang J z* (cos £ + i sin 2) and X= k tang ^ tf. cos t, Y= & tang 
^ u . sin £ which is, as will be easily seen, the stereographical 
projection. 

If we put more generally fv = ke tXv , we have 

X = k tang \ u . cos Kt , Y= & tang J w . sin A. U 
For the scale of linear dimensions in the representation, we 
obtain here n = a 2 sin u 9 , N = 1, $£p = i\ke xXv , and hence 



, A A- tang * m 
a sin w 



It is evident that the representation of all points for which u 
is the same, will form a circle, and the representation of those 
points for which t is constant, a straight line, as also that the 
different circles corresponding to the different values of u are 
concentric. This affords a very useful projection for maps, if 
a part only of a sphere is to be represented. It will then be 
best to choose A in such a manner as to make the scale the 
same for the extreme values of u which will make it smallest 
towards the middle. If we suppose the extreme values of u 
to be u° and u' 9 we must put 

log sin u'— log sin u° 
log tang f u'— log tang £ u \ 

The sheets Nos. 19—26 of Prof. Harding's Celestial Maps, 
are drawn agreeably to this projection. 

11. The general solution of the example given in the pre- 
ceding article, may be exhibited in another form, which de- 
serves to be mentioned on account of its neatness. 

In conformity to what has been proved in article 6, we have 

["tang \ u (cos t + i sin t) being a function of t -f i log cotang \ u 

, A T , , . • • .\ sinw .cos t-\- i sin m .sin/ x-\-iy~i 

and tang \ u (cos t + z sm t) = — - =— -— I 

& z v * i + cos u a+z J 

for the general solution likewise these formulas : 

X+iY =/ ^L, X-t Y =/'^ that is, X must be 

u a+z u a-\-z 

made equal to the real, and i Y to the imaginary part of/ 7 ~^- 

■ f f denoting 



Prof. Del Rio's Analysis of two new Mineral Substances, 113 

f denoting an arbitrary function. It will be easily seen that 

instead of/ x * y , any arbitrary function of y ~7% or of rjT^-p 

may be taken. 

[To be continued.] 



XVII. Analysis of two new Mineral Substances, consisting of 
Bi-seleniuret of Zinc and Sulphuret of Mercury, found at 
Cidebras in Mexico. By Professor Del Rio*. 

Tj^ACH step of the traveller in this Republic discovers to 
-" him something new. Mr. Joseph Manuel Herrera, in an 
excursion to Culebras, near the mining district of El Doctor, 
found a mineral resembling cinnabar, accompanied by metallic 
quicksilver, in the limestone which overlies the red sandstone 
(arenisca rosea), and he gave me a few small specimens of this 
substance. Some considerable time afterwards Col. Robinson 
gave me an additional quantity, informing me at the same 
time that Dr. Magos had obtained two ounces and a half of 
quicksilver from sixteen ounces of the ore. 

Under the blowpipe the red ore burns with a beautiful 
violet-coloured flame, accompanied by much smoke of a most 
offensive smell, resembling that of rotten cabbage : the resi- 
due is a grayish-white earthy matter. 

Intimately admixed with the red mineral is another sub- 
stance so strongly resembling light gray silver ore, that I ac- 
knowledge that I mistook it, at first, for this ore of silver. 
My only doubt on the subject arose from the consideration 
that gray silver ore and cinnabar are never found together. 
It differs, however, from gray silver in yielding a blacker pow- 
der when scraped, and which stains more than the powder of 
the latter. Under the blowpipe nearly the same phaenomena 
are observed as when the red mineral is submitted to the same 
test. According to Mr. Chovell, the specific gravity of the 
gray substance is 5'56, after having been carefully cleared by 
washing from the calcareous spar of the matrix. That of the 
red substance, after having also been carefully separated from 
the spar, is S^; while the specific gravity of hepatic mercury 
exceeds 5*8. 

The analysis of these minerals is very easy where great pre- 
cision is not required. Nothing more is necessary than to 
put fifty grains of the ore in a small retort on the fire ; mer- 
cury, selenium, and a small quantity of sulphur are imme- 

* Communicated by A. F. Mornay, Esq. 
New Series. Vol.4. No. 20. Aug. 1828. Q diately 



114- Prof. Del Rio's Analysis of two new Mineral Substances. 

diately sublimed, and a sub-oxide of zinc remains at the bot- 
tom of the retort. That the metallic gray powder attached 
to the upper part of the retort is selenium, is proved by the 
red colour of the light transmitted through it, and by the high 
metallic lustre of the surface in contact with the glass. The 
residuum is shown to be sub-oxide of zinc by its solubility in 
acids, and by its being redissolved by an excess of potass, 
soda or ammonia, after having been precipitated by the alkali 
from an acid solution : also by its phosphorescence when fused 
by the blowpipe, by the white smoke which it emits and which 
attaches itself to the charcoal, and by the enamel which it forms 
with borax and microcosmic salt. 

In order to determine the proportions of the component 
parts of the gray substance, I first treated it with concentrated 
sulphuric acid, which dissolved the mercury and some of the 
zinc ; I then applied nitric acid, which dissolved the remain- 
der of the zinc, and I finally employed nitro-muriatic acid to 
oxidate the selenium. By these operations 1*5 grain of sul- 
phur, without any red tinge, and which I therefore suppose to 
be pure, was separated ; and after the nitro-muriatic acid had 
been distilled offj selenic acid was sublimed : this was partly in 
acicular crystals, and partly in a dense white mass half fused 
and semi-transparent. There remained at the bottom of the 
retort the sulphate of lime formed by the sulphuric acid used 
in the first process, and the lime of the calcareous spar acci- 
dentally mixed with the mineral. 

I think that it may be deduced from the foregoing experi- 
ments and others, that the gray mineral is composed of 

Selenium 49 

Zinc 24 

Mercury 19 

Sulphur V5 

93-5 
which, with the addition of six grains of lime obtained, will 
amount to 99*5. But the lime merely accompanies the ore, 
and does not enter into its composition. 

The gray mineral is therefore a bi-seleniuret of zinc united 
to a protosulphuret of mercury, the latter giving, in my opi- 
nion, the dark or gray colour to the mineral. 

The red mineral will also be a bi-seleniuret of zinc, but the 
mercury will be in the state of a bi-sulphuret or cinnabar, 
which will give the red colour to the mineral. 

These two minerals are therefore in my view, and accord- 
ing to Berzelius, two distinct genera, because they are ex- 
pressed by two distinct formulae, as is the case with orpiment 

and 



Mr* Pentland's Observations on the Peruvian Andes. 115 

and realgar ; that is to say, that the gray mineral will be ex- 
pressed by the formula Zn Se 4 + HgS. The red mineral by 
the formula Zn Se 4 + H#S 2 . 
Mexico, December 1, 1827. (Signed) A. Del Rio. 



On one occasion I distilled the mineral alone, and I 
poured spirit of wine into the receiver, when I observed at the 
bottom a drop of yellow oil, which in time tinged the alcohol 
of a beautiful yellow : on the addition of water, the colour dis- 
appeared without any precipitate being thrown down. I pre- 
sume that this was the same substance noticed by Berzelius, 
as being formed on the admixture of selenic acid and anhy- 
drous muriatic acid with selenium, in which case both these 
acids must exist in the mineral. I detected the muriatic by 
means of nitrate of silver; but no sensible precipitate of sele- 
niate of silver was obtained by the addition of cold water to 
a boiling nitric solution, perhaps because the quantity was too 
small. 



XVIII. Observations on the Peruvian Andes, in reply to a 
Paper by M. Coquebert de Montbret, in the Annales des 
Sciences Naturelles. By J. B. Pentland, Esq, 

To the Editors of the Philosophical Magazine and Annals. 
Gentlemen, 
r iPHE last Number of the Annales des Sciences Naturelles, 
-*■ (vol. xiii. p. 420) contains a paper by Mons. Coquebert de 
Montbret, entitled " Note sur quelques Montagnes du Haul 
Perou" purporting to be founded on a memorandum of some 
of my measurements of the Peruvian Andes, which I had 
communicated to that gentleman in February last. 

The memorandum in question was drawn up, in the course 
of conversation, for Mons. de Montbret's private information ; 
and I distinctly stated to him at the time that the results 
ought merely to be considered as approximative ; since I had 
not the detailed notes of my observations at hand, and the 
calculations on which they were founded, required a careful 
revisal, before they were submitted to the public, — having been 
made in the midst of the fatigues and annoyances attendant 
on a tedious journey. I have therefore seen with regret, 
that a part of my observations has been rendered public in 
the unconnected and inaccurate manner in which they are 
brought forward in the paper in question : and I shall feel 
sincerely obliged by your giving an early insertion to this 

Q 2 letter, 



116 Mr. Pentland's Observations on the Peruvian Andes, 

letter, in which I shall confine myself to the correction of 
some of the errors into which Mons. de Montbret has fallen, 
and to rebutting the conclusions drawn by this writer and 
Mons. Brue against the accuracy of my measurements. 

The principal objection raised against the great elevation 
which I have attributed to certain peaks of the Peruvian Andes, 
situated between the 14th and 17th parallels of south latitude, 
consists in an assumption, that if the geographical position in 
which my astronomical observations have placed these moun- 
tains be correct, they must be easily seen from the coasts of 
the Pacific Ocean, and could not have hitherto escaped the 
attention of the navigators frequenting the ports of Peru situ- 
ated in or near the same latitude. , 

To meet this inference, I take the liberty of annexing an 
extract from a letter, which, in my own justification, I have 
judged it necessary to address to Mons. Coquebert de Mont- 
bret, in reply to his observations : — 

" The great chain of the Andes, between the 14th and 20th 
parallels of southern latitude, is divided into two longitudinal 
and parallel ridges, or Cordilleras (the name by which they 
are designated by the Creole population of Peru). These two 
Cordilleras are separated by a very extensive interalpine valley, 
the mean elevation of which is 12,600 feet; its southern por- 
tion is traversed by the river Desaguadero, whilst its northern 
is occupied by the celebrated lake of Titicaca, on the shores 
and in the islands of which Peruvian civilization and the Em- 
pire of the Ingas had their origin. 

" The western cordillera, or, as it is called, the Cordillera 
of the Coast, separates the valley of the Desaguadero (the 
Thibet of the new world), and the basin of the lake of Titicaca, 
from the shores of the Pacific. Many of its peaks exceed 
20,000 feet in elevation, and in it are situated several active 
volcanoes; whilst the eastern cordillera, composed chiefly of 
transition and secondary rocks (grauwacke-slate and new- 
red-sandstone), separates the same valley from the extensive 
plains of Chiquitos and Moxos, and the confluents of the rivers 
Beni, Mamore and Paraguay, from those streams which 
empty themselves into the lake of Titicaca, and into the river 
Desaguadero. 

" The eastern cordillera of the Peruvian Andes is situated 
within the political limits of the Republic of Bolivia ; and it 
presents, between the 14th and 17th degrees of latitude, an 
almost continuous ridge of snow-capped mountains, the mean 
elevation of which exceeds 19,000 feet It is upon this snowy 
range of the eastern cordillera that rise the most elevated 
mountains hitherto determined throughout the entire extent 

of 



Mr. Pentland's Observations on the Peruvian Andes, 117 

of the Andean chain. The Nevados of Utimani and of Sorata 
(those referred to in Mons. de Montbret's paper) surpassing in 
height the giants of the Columbian prolongation of the Andes, 
Chimborazo, Cayambe and Antisana, — and approaching near 
to the most elevated peaks of the Himalaya range. 

" The mountain of Illimani is situated in the Bolivian pro- 
vince of La Paz, twenty leagues E.S.E. of the city of the same 
name. Like Chimborazo it forms the most southern limit of 
the snowy range to which it belongs ; and according to my 
astronomical observations, (made at La Paz, and at the hamlet 
of Jotoral near to its northern base,) it is placed between 
16° 35' and 16° 40' south latitude ; and between the 67th and 
68th degrees of west longitude, reckoned from the meridian of 
Greenwich. Its summit forms an elevated ridge, surmounted 
by four peaks, disposed on a line from north to south and 
parallel to the axis of the chain. The most northern of these 
eminences attains an elevation, according to my measurement, 
of 24,200 British feet, or 12,000 feet above the city of La Paz ; 
but the southernmost peak appeared to me to be still more 
elevated, although it was impossible to ascertain the exact dif- 
ference from my station. This stupendous mountain is com- 
posed of grauwacke and transition-slate, with frequent inter- 
stratifications of quartz-rock and flinty-slate; which in their 
mineralogical structure and geological relations entirely re- 
semble those of the valleys of the Maurienne and Tarentaise in 
the Savoy Alps : and with these schistose rocks are associated 
large masses of porphyry, of sienite, and of true granite, in 
the form of veins and beds. The transition -slate is traversed 
by numerous veins of quartz, containing minute portions of 
gold and of auriferous pyrites; many of which veins were 
worked by the aboriginal Peruvians, at an elevation of 1 6,000 
feet above the level of the sea, at a very remote period, prior 
to the arrival of their Europaean invaders. 

" The most eastern point of the coast of the Pacific, on the 
same parallel of latitude with the mountain of Illimani, is si- 
tuated between the roads of Quilca (latitude 16° 42'), and the 
headland or Morio of Arequipa (latitude 16° 30' S.) ; and 
between the meridians of 72° 40', and 73° 20' W. of Green- 
wich, — adopting a mean of the observations of Captain Basil 
Hall, and of Alessandro Malespina. Illimani is consequently 
separated from the nearest point of the coast of Peru, by an 
horizontal distance equal to 5° 30' of longitude, or to 310 
nautical miles. This fact in itself is sufficient to show the im- 
possibility of discovering from the coast of Peru, that moun- 
tain, or indeed any part of the eastern cordillera of the Andes 
(the axis of which, between the 14th and 17th degrees of lati- 
tude, 



118 Mr. Pentland's Observations on the Peruvian Andes. 

tude, is nearly parallel to the meridian), — even supposing the 
intervening space to be perfectly horizontal, and not inter- 
rupted, as I have already shown it to be, by the elevated mass 
of the western cordillera, — some of the peaks of which, as well 
as the trachytic dome which towers over the valley of Chu- 
quibamba, N.N. W. of Arequipa, rise to an elevation exceeding 
22,000 feet*." 

I am therefore at a loss to imagine how two gentlemen, 
possessing the acknowledged acquirements of Messrs. Brue 
and de Montbret, could have raised such an objection to the 
accuracy of my observations as that conveyed in the paper of 
the latter ; since a reference even to the old and inaccurate map 
of South America, by Olmedilla de la Cruz, or to the incorrect 
compilation of Alcedo, must have rendered evident to the 
merest tyro in geographical science, the physical impossibility 
of descrying an eminence no more than 24,200 British feet 
above the level of the ocean, from a distance which exceeds 
100 nautical leagues. 

On the northern prolongation of the eastern cordillera of 
the Bolivian Andes, and nearly in the centre of the snowy range 
above mentioned, rises, in latitude 15° 30' S., the Nevado of 
Sorata, from the midst of a group of snow-capped pinnacles, 
some of which attain an elevation of 23,000 feet. The Nevado 
of Sorata is situated to the east of the large Indian village of the 
same name, and is elevated 25,200 feet above the level of the 
sea, or 12,450 feet above the waters of the lake of Titicaca: — 
as deduced from a trigonometrical measurement taken from 
the shores of the lake, and from a determination (made at a 
less distant station) of the height of that portion of the sum- 
mit which is placed above the superior limit of perpetual snow ; 

* The city of Arequipa, one of the handsomest in South America, is si- 
tuated at the western base of the western cordillera, in the midst of a fer- 
tile valley, watered by the streams of the Arequipa and Inquocajo, which 
descend from the adjoining Andes. The valley of Arequipa is bounded on 
its northern and eastern sides, by three snow-capped mountains ; that in 
the centre, the volcano of Arequipa, resembling in form, and being nearly 
equal in elevation to Cotopaxi : whilst towards the south and west the 
valley is separated from the shores of the Pacific Ocean, by a low range of 
trachytic eminences j and by an arid sandy desert which occupies an extent 
of fifty miles in breadth. The mean of my observations, as deduced from 
an extensive series of meridian altitudes of Achernar, Canopus, a. Arietis, 
Capella, and Saturn, places the house of the British consulate at Arequipa 
in latitude 16° 23' 58" ; and in longitude 71° 20' 0" W. resulting from ob- 
servations made with two good chronometers, and from several sets of 
lunar distances. The elevation of Arequipa above the level of the neigh- 
bouring ocean, is 7797 feet; being the mean of 170 barometrical observa- 
tions, made during thirteen successive days with an excellent barometer by 
Fortin, and calculated according to the formula of Laplace, 

a limit 



Mr. Sowerby on the Penetration of the Seainto corked Bottles. 119 

a limit which, between the 15th and 17th degrees of south 
latitude, and on the sides of the Bolivian Andes, seldom de- 
scends below 17,100 feet above the sea. 

The great mass of the eastern cordillera, situated north of 
the parallel of 1 7° S. is likewise formed of the transition rocks 
above enumerated ; the sienitic or crystalline rocks becoming 
more abundant on its northern prolongation. The schistose 
rocks here also abound in auriferous veins ; and through the 
deep dells which intersect them, descend the numerous auri- 
ferous torrents, which empty themselves into the river Beni 
and its confluents, and give to the tropical district bordering 
on the river of Tipuacio (in the province of Larecaja), the 
fairest claim to the title of the El Dorado of the new world,— 
from the great quantities of gold, which have been and are 
still collected from the alluvial deposits that form its banks. 

I am, Gentlemen, yours, &c. 

June 25, 1828. J. B. PENTLAND. 



XIX. On the Penetration of Water into stoppered and corked 
Bottles sunk to a greatDepth in the Sea. By J. de C. Sowerby, 
Esq. F.L.S. $c. 

To Richard Taylor, Esq. 
Dear Sir, 
TV/I" ANY papers having at different times appeared upon the 
■** popular paradox, a bottle filling with water when sunk 
to a great depth in the sea, however well it may have been 
corked and sealed, without any satisfactory explanation having 
been given, and seeing the subject resumed by Dr. Green, in 
your Philosophical Magazine for this month, — I am induced to 
send you my explanation of the phenomenon. 

Dr. Green thinks that by proving (as others had done) that 
the water would not penetrate glass, he had reduced the ques- 
tion into very narrow limits ; and that the water enters glass 
vessels through the " cork and all its coverings in consequence 
of the vast pressure of superincumbent water, in the same 
manner as blocks of wood are penetrated by mercury in the 
pneumatic experiment of the mercurial shower." 

It may be concluded from recorded experiments, that well- 
fitted glass stoppers (by the bye, every chemist knows such 
are rarely to be obtained as will confine the vapour of nitric 
acid) will exclude the water; corks when properly protected 
will also prevent the water from entering. When mercury 
is made to pass through a block of wood by pneumatic pres- 
sure, it finds its way by the longitudinal tubes ; such tubes do 

not 



120 Dr. Front's further Remarks on Messrs.Tiedemann 

not exist in cork. My explanation is this ; cork is elastic, and 
by the pressure of the sea is readily condensed, and conse- 
quently much diminished in bulk, first that part out of the 
bottle where the sides are not protected by the neck, and then 
gradually the remaining length until the cork, separated en- 
tirely from the glass, affords a free passage for the water, un- 
less the sealing or wrapper be of such a tenacious and ductile 
nature as to adhere to the glass and the cork so as to fill up the 
space that would otherwise be left, and yet not yield com- 
pletely to the pressure ; if it be brittle, it either separates from 
the glass, or cracks, or both, allowing a free passage to the 
water. Even pitch when cooled in the deep water would be 
very brittle and crack or separate from the bottle readily, and 
it would resume its former ductility and appearance upon re- 
turning through the warm surface : this and similar considera- 
tions will show how a trifling difference in closing the bottles 
may produce considerable differences in the results of the ex- 
periments. I remain, yours truly, 

2, Mead Place, Lambeth, July 12, 1828. J. DE C. SoWERBY. 



XX. Some further Remarks on Messrs. Tiedemann and 
Gmelin's Observations on the Acids of the Stomach. By 
Wm. Prout, M.D. RR.S* 
f TVHE observations of Messrs. Tiedemann and Gmelin on 
-*- my paper published in the last Number of the Philoso- 
phical Magazine and Annals, seem to me to be intelligible 
only on the two following assumptions. First, that the method 
employed was adopted at random and without any preliminary 
inquiry, and was intended to include every possible case ; and 
secondly, that on the faith of this random method, / denied 
generally and under all circumstances the existence of every 
other acid except the muriatic acid, in the stomachs of ani- 
mals. Now whether these assumptions can be fairly drawn 
from my paper, I, as an interested individual, can scarcely, 
perhaps, be admitted as competent to decide ; but I can truly 
say at least, that I never intended that such inferences should 
be drawn, nor was aware that any thing had been stated to 
authorize them. 

With respect to the first of these assumptions it may be said, 
that the nature of the gastric fluids, and especially the acid, had 
occasionally occupied my particular attention for many years ; 
and that during the summer before my paper was published, 
I had set about the inquiry in earnest, and with the determi- 

* Communicated by the Author. 

nation, 



and Gmelin's Observations on the Acids of the Stomach. 121 

nation, if possible, of putting the matter at rest. With this 
view a number of animals were fed in various ways ; that is to 
say, on substances both natural and unnatural to them, and the 
contents of their stomachs subjected ,to analysis. The ex- 
amination was conducted in the, most rigorous manner, and 
varied in every possible way that I could devise ; and up to 
the period at which my paper was sent to the Royal Society, 
I completely satisfied myself, that in every instance the acid 
present was the muriatic acid and no other, at least in any 
appreciable quantity. Now it was in the knowledge thus pre- 
viously acquired, and not at random, that the method pro- 
posed was founded ; and among a variety that were tried, the 
one in question was ultimately chosen as comprehending every 
point that had then occurred to me. If it be objected that 
these preliminary experiments ought to have been given, I can 
only say, that I did not at the time think this necessary, nor 
do I now. The muriatic acid was not a new substance, nor one 
difficult to be identified : besides, such a preliminary inquiry 
seemed to be sufficiently indicated by the method proposed ; 
for who would ever think of proposing a formal method of 
analysis, involving the quantities of substances, without deter- 
mining beforehand what those substances were ? Further, my 
paper was intended to be little more than a simple announce- 
ment of an important fact, which, before it could be established, 
I well knew must be corroborated by other experience than 
mine ; and lastly, something must be ascribed to a sort of in- 
nate antipathy to long-winded dissertations, which is too apt 
to cause me to err on the side of brevity. 

Messrs. T. and G. observe, that considering my method 
quite perfect, I infer from it the absence of all other acids, ex- 
cept that of the muriatic acid in the gastric fluids. To this I 
answer, that under the circumstances to which it was applied, 
I considered it then, and do still, as quite perfect: and as 
the residuum after combustion could not have been neutral 
if the acid had been of a destructible nature, because the 
quantity of potash required to saturate the free acid was 
more than sufficient to decompose the whole of the muriate 
of ammonia present, — the argument even in this point of view 
was strictly correct, though acknowledged to be imperfect if 
applied generally *. This argument was given, because it was 

the 

* Messrs. T. and G. will, I trust, give me credit when I assert that I was 
perfectly aware of all the chemical objections they have raised, and many 
more to the same effect ; and never should have thought of applying the 
method in question in a new case when the nature of the acid was un- 
known, and particularly in the case of a destructible acid in conjunction 
with the muriate of ammonia. The fact was, that I detected free muriatic 

New Series. Vol. 4. No. 20. Aug. 1828. R acid 



1 22 Dr. Frout'sjurther Remarks, Sfc. 

the only one bearing on the point in question that was strictly 
deducible from the method employed; and more could not 
have been well said without destroying the unity of my design, 
and entering on details which, for the reasons above stated, I 
concluded would have been taken for granted. 

With respect to the second assumption; namely, that I de- 
nied generally, and under all circumstances, the existence of 
every other acid in the stomachs of animals, except the muriatic 
acid, — I can only say, that nothing was further from my inten- 
tion. On the contrary, I distinctly alluded to the " occasional 
presence of other acids in the stomach," taking it for granted 
that such an occurrence must sometimes happen. What I did 
assert, and what I again assert is, that in the cases related, and 
in all others in which a rigorous examination was instituted 
up to the period mentioned, no other acid did occur in any 
appreciable quantity ; and I acknowledge that in consequence 
of this experience, I was induced to conclude that the presence 
of other acids was comparatively of rare occurrence, and my 
subsequent experience decidedly favours this conclusion. I have 
already said, that since my paper was read before the Royal 
Societjr, I have occasionally, by means precisely similar to 
those formerly employed, detected the presence of combustible 
acids in the stomach, and have expressed a belief that these 
acids were probably derived from the food ; and in several of 
the instances, I have no doubt this was the case. I wish how- 
ever by no means to be understood to deny that the stomach 
occasionally secretes a combustible acid in a free state # , though 

I think 

acid in a fluid ejected from the human stomach so long ago as 1820, but 
then thought that its presence was accidental, or that by some means or 
other I had deceived myself ; and when I commenced the experiments in 
question, I was actually prejudiced in favour of a destructible acid, viz. the 
lactic acid of Berzelius (though the distinct nature of this acid always, I 
confess, appeared to me to be somewhat problematical). In consequence of 
this prejudice,therefore, the inquiry was conducted in a much more rigorous 
and elaborate manner than it probably otherwise would have been ; and 
after a series of the most complete evidence that perhaps was ever brought 
to bear on a chemical point, I was obliged to conclude, is opposition to my 
preconceived notion that the acid was the muriatic and no other. 
On reflecting, however, on this most unexpected fact, I soon saw its im- 
portance, and that, in short, it was one of those leading facts that opens 
up an entire new field of inquiry. So satisfied indeed was I of this, that a 
work on the digestive functions, in which I had been long engaged, and 
which I had actually begun to print, was suppressed ; and since that time I 
have been engaged in an entire new field of research, which I fear will yet 
occupy me for several years to come. 

* Within the last few months I have seen a very remarkable case of dis- 
ease, where the acetic acid seemed to be formed, not only by the stomach, 
but the salivary glands, &c. in great abundance. In this case the breath of 

the 



Mr. Sharpe on the vitrified Port of Dunnochgoil. 123 

I think it more frequently happens that some salt containing a 
combustible acid, e. g. the acetate of soda, is actually secreted ; 
and that this, by being decomposed by the free muriatic acid, 
gives origin to the apparent presence of free acetic acid. 

In conclusion, it may be observed that, during the long 
period that my attention has been turned to this interesting 
subject, a great many curious and most important facts have 
come to my knowledge : in some of these I have been an- 
ticipated by Messrs. T. and G. ; while others appear to have 
escaped their observation, or probably did not occur to them. 
But when I make this statement, I wish it to be distinctly un- 
derstood that I am very far from accusing these gentlemen of 
chemical ignorance, because they failed to point out what pro- 
bably was not present in the substances they examined, or of 
charging them with denying, generally, the existence of every 
thing else that did not happen to fall within the limits of their 
own observation ; — charges which these gentlemen, from not 
sufficiently attending to the general character of my brief 
announcement, have inadvertently brought against me under 
very similar circumstances. 



XXI. On the vitrified Fort of Dunnochgoil, in the Isle of Bute, 
By Samuel Sharpe, Esq. F.G.S.* 

r |^HE fort is on a rocky point at the south-west corner of 
■*- the Isle of Bute, perhaps the point nearest to the Isle of 
Arran. It is at some distance from trees, habitations, and 
higher ground. 

There remains now little more than the ground-plan, which 
may be traced by the vitrified foundations ; but at one part the 
wall is more than a foot high, built of rough stones not much 
larger than bricks, and by vitrifaction formed into one solid 
mass, much like the slag of a furnace. 

The parts can best be described by reference to the follow- 
ing figure. 

From q there is a gradual ascent to the outer chamber 
e fgh> which appears to have been surrounded on two sides 

the patient smelt strongly of vinegar ; the saliva and fluids occasionally 
ejected from the stomach contained also the same acid in abundance, as 
apparently did the perspirable fluid ; for the whole body exhaled a strong 
odour somewhat like sour milk : during this time the urine was strongly 
alkalescent. In another anomalous case, 1 have seen the blood itself strongly 
acid ; the acid was of a combustible nature, but from peculiar circumstances 
it was not satisfactorily proved to be vinegar, though this was probably the 
case. 

* Communicated by the Author. 

It 2 ef 



124 Mr. Sharpe on the vitrified Fort of Dunnochgoil. 

ef and fg by vitrified walls. Between the outer chamber and 
the inner one, abed, 
there is a slight descent, 
which may however for- 
merly have been a ditch 
of some depth. This 
chamber was apparently 
fortified by vitrified walls, 
not only outwards on the 
sides ab and be, but also 
on • the side c d against 
the outer chamber. 

The remains of the 
wall are mostly little 
more than foundations, 
but for part of the way 
between b and c it is 



more than a foot high. 

I found no traces of 
art to prove that the 
neighbouring height n 
was any part of the fort, 
though it is made pro- 
bable by the absence of % 

all remains of wall on the side a dhg. The walls were pro- 
bably only two or three feet thick, which, at least on three 
sides, was all that was necessary where the situation made them 
only accessible to missiles ; and if there were originally any 
others besides those mentioned, they were probably not vitri- 
fied, as no traces of them are now apparent : the ground be- 
low is scattered with fragments of rock, some of which doubt- 
less formed the walls. 

The heights were estimated by guess, and the distances by 
pacing, and have no claims to exactness. 

a b perhaps 70 feet above the shore, nearly perpendicular. 
b c ef ditto, not so perpendicular. 

> a rather steep ascent. 

ad and kg 40 nearly perpendicular. 
Between d and h the side is kept perpendicular by build- 
ing, without vitrifaction or apparent cement. Each chamber 
is about 40 paces long, and 25 paces wide, the space between 
the chambers 3 paces, the gradual ascent from a above 100 
paces. 

The sides b ab and bfq are each about 100 yards from the 
sea ; and near b are the traces of a landing-place on the beach, 

which 




Mr. Seers's Method of solving adjected Quadratic Equations. 125 

which however must be either modern or accidental, as they 
could hardly have withstood the waves for so many centuries. 

I have nothing to add to the received opinion, that it must 
have been built before Roman arts and civilization (and in 
particular the use of mortar) travelled so far north. 

Dr. Macculloch, after describing in the Geological Trans- 
actions, vol. ii. the Fort of DunMacSniochan near Oban (which 
I had intended to visit, but being hindered, visited this in Bute 
instead), combats at length and successfully the opinion, that 
the vitrifaction was the effect of natural causes ; but I think 
the opinion could never have been held by one who had seen 
this fort in Bute, where the traces of art are so evident and 
so undeniable. 

The wall must have been first built, and then made compact 
and solid by vitrifaction, which must have required a conside- 
rable fire to be moved from place to place, as the work pro- 
ceeded. Samuel Sharpe. 



XXII. Method of solving adfected Quadratic Equations. By 
Mr. Joseph Seers ; in a Letter to Mr. Peter Nicholson*. 

Dear Sir, 
f" BEG leave herein to submit to your inspection, &c. the 
A method I discovered and mentioned to you, about two 
months ago, of solving adfected quadratic equations. I flatter 
myself it is quite new ; and I think it inferior to none in pre- 
sent use. It is as follows : 

Whatever be the original form of a quadratic equation, it 
must always be reduced to this formula of three terms; viz. 
x 2 ± p x ± q — 0. 

In this formula, it is to be observed that p is the sum of 
the root, and that q is their product. And having their 
sum, and substituting (d) for their difference, we have, by a 

well-known theorem, the two roots in this expression + p — . 

in which expression the sign of p is always contrary to what 
it is in the above formula. Moreover, we have, as before ob- 
served, £i- x £j^- = ± q. In which equation d = + 



V p~ + 4 q : here the sign of q is contrary to what it is in the 
formula. Hence, l£±± = ±JL±.^UJ^ : an expression 

containing the two roots of the given equation in terms of 
known quantities. 

* Communicated by Mr. P. Nicholson. 

Ex- 



1 26 Prof. Hare's improved Eudiometrical Apparatus* 

Example: — Given x 2 — llx + 35 = 0. To find the values 
of x. 



Here x = ?'gp . Moreover, — — 



d 17- 

X 2 



= 35. 



Hence, 17*— d* =140 or, d 2 = 149. 

.\ J = + V 149 = + 12 . 206 + &c. 

.-. x = (17 + 12 . 206 -f &c.)-r-2. Or, (17-12 . 206 + &c.)h-2 . 
= 14.603 + &C, or 2.397 + &C. 
I will not trouble you with any more examples, as there is 
no need. I remain, Dear Sir, 

Your most obedient and much obliged servant, 
Chelsea, June 20, 1828. Joseph Seers. 



XXIII. Improved Eudiometrical Apparatus. By R. Hare, 
M.D. Professor of Chemistry in the University of Pennsyl- 
vania *. 

I. Piston Valve Volumeter. 
f" HAVE contrived some instruments for taking volumes of 
**- gas at one time, precisely equal to those taken at another 
time. I call them volumeters, to avoid circumlocution. They 
are of two kinds, one calculated to be introduced into a bell 
glass, over water, or mercury; the other may be filled through 
an orifice, as is usual in 
the case of filling a com- 
mon bottle over the pneu- 
matic cistern. The an- 
nexed figure will convey 
a due conception of one 
of them, which having a 
piston, I call the piston 
valve volumeter. 

The lever L is attach- 
ed by a hinge to a piston 
p, which works inside of 
a chamber C. The rod 
of this piston extends be- 
yond the packing through 
the axis of the bulb B to 
the orifice O in its apex, 
where it sustains a valve, 
by which this orifice is 
kept close, so long as the 

* From the American Journal of Science, with corrections and additions 
by the Author. 

pressure 




Prof. Hare's improved Eudiometrical Apparatus, 127 

pressure of the spring, acting on the lever at L, is not coun- 
teracted by the hand of the operator. 

Suppose that while the bulb of this instrument, filled with 
water or mercury, is within a bell glass, containing a gas, the 
lever be pressed towards the handle, the valve is consequently 
drawn back so as to open the orifice of the apex of the bulb, 
and at the same time the piston descends below an aperture 
A in the chamber. The liquid in the bulb will now of course 
run out, and be replaced by gas, which is securely included, 
as soon as the pressure of the spring is allowed to push the 
piston beyond the lateral aperture in the chamber, and the 
valve into the orifice O, in the apex of the bulb. 

The gas thus included may be transferred to any vessel, in- 
verted over mercury or water, by depressing the orifice of the 
bulb below that of the vessel, and moving the lever L, so as 
to open the aperture A in the chamber, and the orifice of the 
bulb simultaneously. 

The bulk of gas, included by the volumeter, will always be 
the same ; but the quantity will be as the density of the gas 
into which it may be introduced. Hence in order to measure 
a gas accurately, the liquid, whether water, or mercury, over 
which it may be confined, should be of the same height within, 
as without. This is especially important, in the case of mer- 
cury, which being nearly fourteen times heavier than water, 
affects the density of a gas materially, even when its surface 
within the containing vessel does not deviate sensibly from 
the level of its surface without. 

To remove this source of inaccuracy, I employ a small' sy- 
phon gauge which communicates through a cock, in the neck 
of the bell, with the gas within. In this gauge any light liquid 
will answer, which is not absorbent of the gas. In the case of 
ammonia, liquid ammonia may be used ; in the case of muriatic 
gas, the liquid acid. 

The density of the gas will be in equilibria with that of the 
air, when the bell is supported at such a height as to cause 
the liquid in each tube of the gauge to be in the same level. 

II. Simple Valve Volumeter, 
Besides the lower orifice O, by which it is filled with gas, 
the volumeter which the next figure represents, has an orifice 
at its apex A, closed by a valve attached to a lever. This 
lever is subjected to a spring, so as to receive the pressure re- 
quisite to keep the upper orifice shut, when no effort is made 
to open it. 

When this volumeter is plunged below the surface of the 

water 



128 Prof. Hare's improved Eudiometrical Apparatus. 

water of a pneumatic cistern, the air being allowed to escape, 
and the valve then to shut itself under 
the water, on lifting the vessel it comes 
up full of the liquid, and will remain 
so, if the lower orifice be ever so little 
below the surface of the water in the 
cistern. Thus situated, it may be filled 
with hydrogen, proceeding by a tube, 
from a self-regulating reservoir. If the 
apex A be then placed under any ves- 
sel, inverted duly in the usual way, the 
gas will pass into it as soon as the valve 
is lifted. 

Volumes of atmospheric air are taken 
by the same instrument, simply by low- 
ering it into the liquid of the cistern, 
placing the apex under the vessel into 
which it is to be transferred, and lifting 
the valve: or preferably by filling it 
with water, and emptying it in some 
place out of doors where the atmo- 
sphere may be supposed sufficiently 
pure, and afterwards transferring the air 
thus obtained, as above described, by 
opening the valve while the apex is within the vessel, in which 
the mixture is to be made. In this case, while carrying the 
volumeter forth and back, the orifice must be closed. This 
object is best effected by a piece of sheet metal, or pane of 
glass. 

It is necessary that the water, the atmosphere, and the gases 
should be at the same temperature during this process. 

III. Sliding Rod Gas Measure. 
The construction of this instrument differs from that of my 
sliding rod eudiometers, in having a valve which is opened and 
shut by a spring and lever, acting upon a rod passing through 
a collar of leathers. By means of this valve, any gas, drawn 
into the receiver, is included so as to be free from the possi- 
bility of loss, during its transfer from one vessel to another. 
This instrument is much larger than the eudiometers for ex- 
plosion, being intended to make mixtures of gas, in those cases 
where one is to be to the other, in a proportion which cannot 
be conveniently obtained by taking more or less volumes of 
the one than the other, by means of the volumeters: as for 
instance, suppose it were an object jto analyse the air accord- 




Prof. Hare's improved Eudiometrical Apparatus. 129 

ing to Dr. Thomson's plan of taking 42 per cent of hydrogen. 
The only way of mixing the gases by a volumeter, in such a 




ratio, would be to take the full of the volumeter, 21 times of 
New Series. Vol. 4. No. 20. Aug. 1828. S hydro- 



130 Prof. Hare's improved Eudiometrical Apparatus. 

hydrogen, and 50 times of atmospheric air. By the large sliding- 
rod instrument, this object is effected at once by taking 42 
measures of the one, and 100 measures of the other. 

IV. Barometer-Gauge Eudiometer. 
The following is an engraving of the barometer-gauge eudio- 
meter for explosive mixtures. R is a glass receiver. Within 
the receiver near W is an arc of platina, by the ignition of 
which the gas is inflamed. C is a cock with three orifices, 
either of which may be made to communicate with the re- 
ceiver, according to the position of the lever L. More than 
one of the orifices cannot be open at once, but all may at the 
same time be closed. The barometer-gauge GG is seen be- 
side the receiver, with which it communicates through the 




pipe P, and the valve cock V, by means of which the commu- 
nication between the gauge and receiver may be suspended 
at pleasure. The pipe A conveys to the receiver the gaseous 
mixture from the bell-glass B. By one of the pipes D, a com- 
munication 



Prof. Hare's improved Eudiometrical Apparatus. 131 

munication with the air-pump may be established. The other 
pipe is used when different kinds of gas are to be successively 
introduced, or when a portion of residual gas is to be drawn 
out for examination. T, T are rods, by means of which the 
platina wire communicates with the poles of a calorimotor, so 
as to be ignited, by being the medium of discharge, as often 
as the surfaces are excited by the acid. The calorimotor* 
employed is so constructed, as that the revolution of a wheel 
through a quarter of a circle, is sufficient to raise the vessel 
holding the acid until the galvanic plates are surrounded by it. 
At m is a wooden dish holding mercury for the gauge-tube. 

It is well known to those who are familiar with pneumatics, 
that if a receiver communicate simultaneously with an air-pump 
and a barometer-gauge, the extent of the exhaustion will be 
indicated by the height of the mercury in the gauge-tube ; so 
that if there be a scale of equal parts associated with the tube, 
the quantity of air taken from the receiver at any stage of the 
exhaustion will be to the quantity held by it when full, as the 
number opposite the upper extremity of the mercurial column, 
when the observation is made, to that to which it would ex- 
tend if the receiver were thoroughly exhausted. 

Hence, if on exhausting the vessel thoroughly the mercury 
rise 450 degrees, on admitting a gas freely, 450 parts of the 
gas would replace the air withdrawn ; but if the entrance of 
the gas be restricted, so that a mercurial column is still sus- 
tained in the tube, the quantity of gas which has entered will 
be as much less than 450, as the mercury is above 0. Thus 
for instance, let the mercurial column sustained extend to 1 50 
on the scale, 300 parts of gas will have entered, and if by ex- 
plosion or any other means any number of parts of the gas, 
thus introduced, be condensed, the mercury must rise that 
number of degrees in the gauge f. 

* See Phil. Mag. vol. liv. p. 209. 

f That portion of the bore of the tube which is not occupied by mer- 
cury, adds to the capacity which influences the gauge, and the portion of 
the gauge which is emptied of mercury varies in extent; but as the air 
which remains in the gauge is not subjected to the explosion, the extent 
of the condensation is uninfluenced by it. 

A slight error may arise from the sinking of the mercury in the dish, as 
the quantity in this receptacle lessens by its rise in the tube; and vice 
versa when subsidence ensues. This movement will be to the movement 
of the mercurial column in the tube, as the square of its diameter to the 
square of the diameter of the mercurial stratum in the dish ; and the diame- 
ters of these being respectively as 20 to 1, it would be 1-400 of the whole 
height of the scale : this difference may be allowed for, or may be remedied, 
by raising or lowering the dish, by an appropriate screw, or employing a 
dish of a superficies so large, and a gauge-tube with a bore so small, as to 
render the effect of the rise, or subsidence of the mercury in the gauge, in- 
significant. 

S2 The 



132 Prof. Hare's improved Eudiometrical Apparatus. 

The receiver is a stout glass tube, which tapers from two 
inches, in diameter, internally, to one inch ; being open at the 
larger end, at the smaller end closed. This form was adopted 
as combining strength, to resist explosions, with a capacity to 
hold larger quantities of gas than have heretofore been ex- 
ploded in eudiometers. It must be evident that the larger the 
quantities of gas operated with, the less upon the whole will 
be the influence of any minute leakage, or error in measure- 
ment. 

The tube is cemented at the larger end into a brass fer- 
rule, which is screwed into a casting of the same metal, fur- 
nished with iron feet. Into the same casting, a brass plug 
screws, through which are inserted stout wires, one of them 
insulated, for producing galvanic ignition, in an arc of platina 
wire, as already described in the case of my other eudiome- 
ters *. 

With the gauge-tube, is associated a scale divided into 450 
equal parts. Instead of inhaling successively due portions of 
hydrogen and atmospheric air, as heretofore described, I have 
found it better to mix them previously in known volumes, by 
means of the volumeters, described in the preceding articles. 
Having by the aid of one of those instruments made a mixture 
of one part of hydrogen, with two of atmospheric air, it fol- 
lows, that if 300 measures be taken by a sliding-rod eudiome- 
ter, or other adequate means, there will be a mixture, in the 
quantity so taken, of 200 parts of atmospheric air, and 100 of 
hydrogen. In case equal volumes of these aeriform fluids be 
mixed into one bell-glass, 200 measures would contain 100 of 
each. This mode of procuring such mixtures, is preferable 
from its saving trouble, and lessening the chances of error in 
the measurement ; and because the gaseous fluids become more 
thoroughly blended, — a result which does not follow their ad- 
mixture as immediately as might be expected. 

Having prepared a mixture of two volumes of atmospheric 
air with one of hydrogen, and the receiver being exhausted 
as far as practicable, if any small quantity of the mixture be 
exploded in it, by exciting ignition in the platina wire W, all 
the oxygen will be condensed. The residuum, consisting of 
hydrogen and nitrogen, will not interfere with the result of 
any subsequent experiment, although the receiver should not 
be thoroughly exhausted. Under these circumstances, let the 

* One of the greatest difficulties which 1 encountered, was in the imper- 
fection of stop-cocks, in the common form. This I obviated by two con- 
trivances of my own; one invented about sixteen years ago, the other in 
the summer of 1825. Of these I shall publish a description, with engrav- 
ings, as soon as I conveniently can. 

exhaustion 



Prof. Hare's improved Eudiometrical Apparatus, 133 

exhaustion be carried to 400 degrees, and let 300 measures of 
the mixture enter, so as to depress the mercury in the gauge 
to 100 on the scale. An explosion being effected, the mercury 
in the gauge will rise at first to about 215 degrees, and after 
the gas shall have regained its previous temperature, will be 
found somewhat above 220 degrees. 

Of course a deficit will have ensued of more than 120 
parts, of which one-third, or a little more than 40 parts, will 
be the quantity of oxygen in 200 parts of the air, subjected to 
analysis. 

In order to ascertain the influence of temperature, a ther- 
mometer is placed in the receiver, the state of which is noted 
before and after explosion ; and the deficit is estimated either 
by allowing for the difference produced by the temperature, 
or awaiting the refrigeration until the mercury in the ther- 
mometer be at the same height as before the explosion. 

From this account of the barometer-gauge eudiometer, and 
those previously given of the sliding-rod instruments*, it must 
be evident that I have contrived three methods of analysing 
the atmosphere, or other mixtures containing oxygen or hy- 
drogen gas. 

In the barometer-gauge instrument, the deficit is known by 
its effect upon the mercury in the gauge-tube ; in one of the 
sliding-rod instruments, the deficit is compensated by water, 
and the quantity of this liquid which enters for this purpose, 
is known by the portion of the sliding rod which remains with- 
out, after excluding the residual gas. In the instrument with 
the sliding rod and gauge, the deficit is compensated by intro- 
ducing the rod, the gauge enabling us to know when it has 
been introduced sufficiently; while the graduation shows the 
ratio of the gaseous matter condensed, to the quantity confined. 

When the diversity of these methods is considered, it is 
pleasing to observe but little difference in the results obtained 
by them. 

A great number of experiments performed by means of the 
barometer-gauge eudiometer, or those of the sliding-rod con- 
struction, over water and over mercury, gave 20 -^^ as the 
quantity of oxygen in 100 parts of the air. In twenty expe- 
riments the greatest discordancy did not amount to £jjfc$th 
part in 100 measures of air. 

In lieu of the glass receiver a strong metallic vessel may be 
used, as for instance, one of the iron bottles employed to con- 
tain mercury. The igniting wire may be placed so as to be 
visible in a very stout glass tube projecting from the bottle. 

* See Phil. Mag. vol. liv. p, 209. 

But 



134 Notices respecting New Booh. 

But a glass tube is not necessary, as, without seeing the igni- 
tion, the explosion will be known to take place by the noise 
which it makes, and the movement of the mercury in the 
gauge. 

[To be continued.] 



XXIV. Notices respecting New Books. 

An Appendix to the First Volume of an Introduction to Practical 
Astronomy. By the Rev. W.Pearson, LL.D. F.R.S. Treasurer 
of the Astronomical Society. 

THE Rev. Dr. W. Pearson has just published an Appendix to 
his First Volume of An Introduction to Practical Astrono- 
my, containing eleven sheets ; in which he has shown that his series 
of XIV Tables, computed from constants of aberration and nuta- 
tion approved by Zach, Delambre, Bessel, &c. will determine the 
corrections due to any other coefficients that may be deemed pre- 
ferable, in the present improving state of practical astronomy ; and 
without altering the mode of computation otherwise than by the in- 
troduction of one constant logarithmic factor in each operation, 
which converts one result into the other; and thus renders these 
tables permanent under all the changes of coefficients, which future 
observations may render necessary. The author has also taken 
occasion to correct some erroneous computations that had before 
escaped his notice ; and has given an additional list of typographi- 
cal errata^ He has likewise added a catalogue of 520 zodiacal stars, 
including their subsidiary numbers, for facilitating the computation 
of their corrections ; as well in longitude and latitude, as in right 
ascension and declination ; all which stars are subsequently arranged 
in the order of right ascension, in a table of fourteen quarto pages, 
in such a manner, that it exhibits those stars in succession that are 
liable to suffer occultation at any given time, by having reference 
only to the moon's longitude and place of her node, as given in the 
Nautical Almanac : and what renders this classification extremely 
convenient, those stars that will suffer an occultation as observed in 
England, or in the same parallels of latitude, are 1 distinguished from 
those that will be seen occulted on other parts of the globe. 

We are authorized to state, which we have much pleasure in 
doing, that the second volume, describing the instruments used in 
practical astronomy, with the methods of adjusting and using them, 
is in a state of great forwardness, and will probably be ready for 
publication in the course of three months from the present time. 

On the Curative Influence of the Southern Coast of England, especially 

that of Hastings : with Observations on Diseases in which a Residence 

on the Coast is most beneficial. By William Hauwood, M.D. 

London, 1828 ; post 8vo, pp. 326. 

This work is an interesting and useful combination of scientific and 

medical information, adapted to the use of invalids who are desirous 

of 



Notices respecting New Books. 135 

of benefiting by the invigorating breezes of our southern Coasts, as 
well as to that of their medical advisers. It describes the peculiarities 
of climate, with respect especially to their influence on disease, which 
are presented on the southern coasts, and discusses, with consider- 
able success, some of the causes of this influence. It comprises at 
the same time a general view of the various physical characteristics 
of the district to which it relates ; such as is calculated to entertain 
the mind of the invalid who may consult it. To some of the obser- 
vations on the effect of atmospheric variations on the human body, 
we do not feel disposed to subscribe - } but the reasoning on this sub- 
ject does not affect the general merits of the work. The contents of 
the work are arranged in the following order : 

The varied nature of our coasts 5 causes tending to affect the tem- 
perature of coast-situations, more especially that of the southern 
coasts 3 the Hastings coast, its geological character, choice of si- 
tuation it affords to invalids in elevation and in temperature, ks 
other peculiarities, table of its temperature 5 on the air j influence 
of atmospherical variations on the constitution } on the effects of sea- 
air j on the water of the southern coast 5 general observations on 
bathing j on cold sea-bathing, its effects on the constitution, cir- 
cumstances which render it inadmissible, precautions in its employ- 
ment 5 warm sea-water bathing, its operation on the system ; shower 
and vapour bathing, observations on indigestion and hypochon- 
driasis 3 acute rheumatism 5 chronic rheumatism 5 gout ; consump- 
tion j winter cough 5 asthma ; haemoptysis ; diseases of the liver ; 
the effects of mercurial medicines ; the effects of loss of blood 5 other 
causes of debility 5 diseases of children j scrofula 5 rickets ; maras- 
mus j spasmodic diseases j hooping-cough ; measles j diseases of 
the skin, &c. j notice concerning the chalybeate waters of the Hast- 
ings coast. 

The Royal Society of Gottingen have published a new volume of their 
Transactions, entitled " Commentationes Societatis Gottingensis." 
It contains three papers by Professor Gauss : — 1. Theoria residuorum 
biquadraticorum. — 2. Supplementum theoria? combinationis observa- 
tionum minimis erroribus obnoxiae. — 3. Disquisitiones generates circa 
superficies curvas*. 

Professor Gauss has likewise published (in German) his "Determi- 
nation of the difference of latitude of the observatories at Gottingen 
and Altona," being the astronomical part of his measurement of an 
arc of the meridian. 

The Berlin " Astronom. Jahrbuch for 1830," has been published 
for the first time by Prof. Encke, on an extended and improved plan. 
It contains, besides the ephemeris, four papers by Prof. Encke on the 
calculations of occultations of Stars ; on Interpolation ; on Sex- 
tants, and on Transitsf. 

The well-known eccentric Dr. Gruithuisen, now Professor of 
Astronomy at Munich, who has so frequently amused the public by 
his discovery of flat-roofed buildings, palm-groves, and macadamized 

* See Phil. Mag. and Annals, N. S. vol. iii. p. 331. 
t See p. 141 of the present Number. 

roads 



136 Astronomical Society. 

roads in the moon, has begun publishing a Journal, devoted to astro- 
nomy and geography, under the title " Analecten fur Erd-und Kim- 
mels Kunde." 

The first paper is a minute description of every part of a zenith 
telescope, for the use of a Katachthonian observatory to be built six- 
teen German (seventy-four English) miles below the surface of the 
earth ! ! ! 



XXV. Proceedings of Learned Societies. 

ASTRONOMICAL SOCIETY. 

- . „ pROF. STRUVE communicated the result of his obser- 
une . j~ vations and measurements of the apparent distance be- 
tween the body and the ring of Saturn : from which it appears that he 
is decidedly of opinion that the body of Saturn is not in the centre of 
the ring. From a mean of 15 measurements, he makes the apparent 
distance on the left side equal to 1 1"*272, and on the right side equal 
to 1 1"'390 : the difference is 0"*215. The probable error of these mean 
measurements he considers equal to 0"*024. M. Struve adds some 
slight corrections to his former measurements of the diameters, &c. 
of Jupiter, of Saturn, and of the Ring ; which he has deduced from a 
more accurate determination of the value of his micrometer. 

The next communication was from Mr. Prinsep of Benares, giving 
an account of two eclipses which he had observed at that place in 
the course of the preceding year. The first was a solar eclipse on 
April 26, 1827. The commencement was not observed ; but during 
the course of the eclipse a number of micrometrical measurements 
were taken by means of the five horizontal wires of a Troughton's 
18-inch circle : and he states the end of the eclipse to have taken 
place at 20 h 3 m 7 S ,5 mean time at Benares. Mr. Prinsep then adds, 
u At the period marked as the end of the eclipse, the sun's disc was 
clear of the moon : but, for 10 or 15 seconds later, I remarked, as it 
were, a stretching of the sun's edge toward the point which the moon 
had just quitted. This was apparently the effect of refraction by the 
moon's atmosphere." The end of this eclipse was also observed by 
Mr. Walter Ewer at Cawnpore, at 19 h 56 m 3 S ,5 mean time at that 
place. The second eclipse, alluded to by Mr. Prinsep, was of the 
Moon, on November 3, 1827. It was observed in the same manner 
as the solar eclipse above mentioned. The following is the result of 
his observations, stated in mean time : h m s 

The edge became dull at 8 42 

The edge invisible 8 44 18 

The edge of the same colour as the sky . . 8 45 30 

Decided shadow 8 46 1 

A bright spot becomes invisible 8 52 26 

Immersion of a small star 1 42 14,2 

Moon's transit 1st limb 1 1 45 48,2 

Do. do 2nd limb 11 47 57,1 

End of the eclipse 12 1 6 

Mr. Walter Ewer observed the beginning of this eclipse at Cawn- 
pore, 8 h 35 m 23 8 mean solar time at that place : the difference of 

longitude 



Astronomical Society. 137 

longitude is assumed equal to — 10 m 12 s . Diagrams, illustrating 
the several phases of the eclipse, and apparently drawn up with con- 
siderable care, accompanied these communications. 

Mr. Rumker of Paramatta, in New South Wales, communicated 
the result of several series of observations in which he had been en- 
gaged at the Observatory there. They contained, 1 st. The determina- 
tion of the solstice in December 1826, June 1827, and December 
1827. In deducing the results, he notices the insufficiency of De- 
lambre's formula for the Reduction to the Meridian in cases of great 
altitude : and suggests an alteration when the sun culminates near 
the zenith. 2nd. Observations on the inferior conjunction of Venus in 
December 1826. 3rd. Observations of moon-culminating stars during 
parts of the years 1826 and 1827. 4th. Places of some of the fixed 
stars in the southern hemisphere. 5th. A Catalogue of stars with 
which the great comet of 1825 was compared. 6th. Corrected obser- 
vations of the place of the said comet. 7th. A determination of the 
latitude of the Observatory by reflection with the mural circle. 

The next communication was from Mr. Cumin of Bombay, giving 
a more accurate account of his observations of moon-culminating 
stars at that Observatory, during the year 1825 : from a mean of all 
which, compared with corresponding observations at Bushey Heath, 
and at Greenwich, he deduces the longitude of the Observatory equal 
to 4 h 51 m 9 s east from Greenwich. 

Mr. Baily presented a short account of the two invariable pendu- 
lums, the one of iron and the other of copper, which he had caused 
to be made, agreeably to the order of the Council, and which are in- 
trusted to the care of Captain Foster in his present voyage of experi- 
ment and observation, for the purpose of investigating the possible 
effects of the earth's magnetism in various geographical positions. 
The form and construction of these pendulums are somewhat differ- 
ent from those in general use ; consisting merely of a plain, straight, 
uniform bar of metal : and, as he conceived that there is a consider- 
able advantage in having each pendulum a convertible pendulum, he 
has placed two knife-edges on each bar. This property of 
convertibility, however, instead of being effected by a 
sliding or moveable weight, is produced by filing away one 
of the ends of the pendulum, until the number of vibra- 
tions on the two knife-edges are equal. The mode of making 
a pendulum of this kind he then describes in the following 
manner : Take a plain straight bar of metal, two inches wide, 
half an inch thick (or iths'of an inch if thought preferable) 
and about 62i inches long $ at least it should not be shorter 
than this, prior to the first trial for the adjustment. At five 
inches from one end of the bar should be placed the apex 
of one of the knife-edges, which he calls A, and at the di- 
stance of 39'3 inches therefrom, should be placed the apex 
of the other knife-edge, which he calls B ; each knife edge 
being firmly and properly secured in the usual manner. 
The distance of 39*3 inches is chosen, because the inter- 
vals of the coincidences are in such case about 15 mi- 

New Series. Vol. 4. No. 20. Aug. 1 828. T nutes 3 



138 Astronomical Society. 

mites ; but if an interval of about 10 minutes should be preferred, 
the distance should be about 39 4 inches -. and so in proportion. 

In order to adjust a pendulum of this kind, it must be placed on the 
agate planes, and the number of vibrations determined in the usual 
manner^ beginning, for the sake of regularity, with the knife-edge A) 
then inverting the pendulum, and determining the number of vibrations 
with the knife-edge B. In these preliminary experiments it is not ne- 
cessary to extend the observations beyond one coincidence ; neither is 
it requisite to apply any other correction than for the arc of vibration, 
and for the temperature of the room, since all the other sources of 
error will be common to the two positions of the pendulum, and 
therefore may be rejected in these first trials. If it should be found 
(as will in fact be the case) that the knife-edge B makes a less num- 
ber of vibrations in a day than the knife-edge A, we must file away 
the bar at the end B, until the two knife-edges are perfectly synchro- 
nous. The amount to be taken away can be ascertained by experi- 
ment only i and as we approximate towards the truth we must be 
more cautious in using the file, and more accurate in making the ob- 
servations. In this last step of the process it is difficult in all cases 
to determine the exact quantity that has been filed away j and we 
may sometimes overdo it, so as to cause an inequality in the vibra- 
tions of an opposite kind, and thus render it necessary to add a small 
quantity to the end B. In order to meet this difficulty, Mr. Baily 
caused a small hole to be drilled at the end B, into which a screw 
was fitted j and by means of a small piece of sheet lead inserted un- 
derneath, the adjustment could be carried to any required degree of 
accuracy. 

The principal advantages attending the placing of two knife-edges 
on one and the same bar, Mr. Baily states to be as follows : viz. 1st. 
That we are thereby possessed of two separate and independent pen- 
dulums ; the results of which may be used separately or conjointly at 
pleasure : and each of which is a more complete check on the other 
than when formed of separate pieces of metal, that may probably be 
of different specific gravities, and of different expansive qualities. 2nd. 
That the knife-edges, being once rendered synchronous, will always 
remain so, into whatever part of the world the pendulum may be 
carried -, and thus enable us> if it should be required, to determine 
the length of the simple pendulum at any point of the globe at which 
it may be swung, by merely measuring the distances between the 
knife edges. 3rd. That we are thus furnished with the means of 
ascertaining whether the pendulum has sustained any accidental in- 
jury j since such a fact would be immediately discoverable from the 
inequality in the number of vibrations between the two knife-edges. 
And, even in case of such an unforeseen misfortune occurring, the 
ratio between the two would from that moment remain the same in 
all parts of the world, and answer the same useful purpose of compa- 
rison during the remainder of the voyage. Whereas, in the pendu- 
lum as usually constructed, the effect of such an injury (if not sus- 
pected) might be attributed to the errors of observation : and indeed 
the fact itself could not be ascertained until the return of the ob- 
server to some place where the pendulum had been previously swung j 

leaving, 



Royal Academy of Sciences of Paris. 1 39 

leaving, however, the precise time at which the accident happened 
still undetermined, and not only the observations themselves, during 
some indefinite period, the subject of doubt and suspicion, but pro- 
bably the whole series of no utility or avail. 

Mr. Baily considers that there are also some advantages attending 
the form of this pendulum. For, being uniform in its dimensions, 
without any protuberant bob or projecting tail-piece, it is not so 
liable to accident as the ordinary pendulum, where those parts pre- 
sent opportunities for injury. It is also capable of being packed in 
a more convenient case, and thus rendered more easy of transporta- 
tion, when required as a travelling instrument. But he states that if 
we view it in the light of an instrument intended for the observatory, 
as a means of determining the length of the simple pendulum, where 
both knife-edges are necessary for the solution of the problem, the 
advantages will be more apparent. For, in the construction of the 
pendulum here proposed, none of the parts slide over one another : 
there are no shifting weights, no moveable screws : every thing is 
fixed and stationary, and consequently more peculiarly adapted for 
the determination of so nice and difficult a problem. 

As these pendulums are formed without any tail-piece, it became 
necessary to adopt some other mode of determining the arc of vibra- 
tion. This, Mr. Baily has effected by making the edge of the pendu- 
lum, which is perfectly straight, answer the purpose of the point in 
the tail-piece of the ordinary pendulum : and by this method he was 
also enabled to enlarge the divisions of the scale (which is a diagonal 
one), sO that the hundredth part of a degree occupies the length of 
three-tenths of an inch, and consequently can be read off with the 
greatest ease. 

[The remainder of the Proceedings will be continued in our next Number.] 

ROYAL ACADEMY OF SCIENCES OF PARIS. 

December 10. — The ordonnance of the king approving of the no- 
mination of M. Savart was read. — M. Anatasi communicated a 
new plan for the towing of ships. — M. l'Abbe* Lachevre objected to a 
part of M. Damoiseau's report respecting his chronological tables. — 
M. Chevreul, in the name ofa Commission, made a very favourable re- 
port respecting the memoir of MM. Dumas and Boullay, jun. On the 
formation of sulphuric aether. — MM. DumSril and Dupuytren gave 
an account of the interesting essays by Dr. Senn of Geneva, respect- 
ing the treatment of diseases of the larynx. — M. Geoffroy Saint-Hi- 
laire read a memoir on a small kind of crocodile living in the Nile, its 
organization and habits, and the motives which occasioned its being 
anciently honoured with the appellation of the Sacred Crocodile.— M. 
Cauchy read a memoir on the development of functions and rational 
fractions. — The observations of Mons. Giroux of Buzareingue, on the 
reproduction of domestic birds, were read. 

December 17. — M. Cassini, in the name ofa Commission, made a 
favourable report respecting Mons. A. Brongniarfs memoir On the 
spermatic granules of vegetables. — M. Chevreul gave an account of 
several notices of M. SSrullas relating to the bromides of arsenic, anti- 

T 2 monv, 



140 Royal Academy of Sciences of Paris. 

mony, and bismuth. — M. Girard gave a verbal analysis of several 
works published in America on the occasion of the opening of the 
Hudson canal. — M. Cauchy read a memoir, intitled Usage du calcul 
des re'sidus pour la transformation ou la sommation des series. — M. 
Bonnard read a memoir on the locality of the manganese of Roma- 
neche. — M. F£burier read a memoir, intitled Notice sur la Lune 
rousse, et sur quelques effets de sa lumiere et de celle des autres astres 
sur les ve'getaux. 

December 24. — MM. Raspail and Saigey sent a Notice respect- 
ing the sizing of paper. — M. Buran transmitted several observations 
concerning M. Payen's memoir on a new borate of soda. — M. Ca- 
gniard-Latour sent a memoir relating to the elasticity and change of 
size which metallic wires undergo when they are stretched. — M. Che- 
vallier forwarded a sealed packet relating to the extraction of indigo. 
— M. Tilloy, of Dijon, sent his work on currants. — M. Dumeril read a 
letter from Bretonneau, On the blistering properties of some insects 
of the can tharides -family. — M. Moreau de Jonnes communicated a 
Notice respecting the recent employment of mercurial treatment, both 
internal and external, in Cephalonia, for the prevention of the first 
symptoms of the plague.— M. de Blainville, in the name of a Commis- 
sion, made a report on the memoir of M. Jacobson, intitled Observa- 
tions sur le pretendu developpement desceufs, desmoulettes, et des ano- 
dontes dans leurs branchies. The Section of Mineralogy and Geology 
presented the following list of candidates for the two vacant places of 
Correspondents. Geology : MM. Conybeare, of London j Buckland, 
of Oxford; MacCulloch, of London j Freisleben, of Freyberg j Char- 
pentier, of Bex. — Mineralogy : MM. Mitscherlich, of Berlin ; Gus- 
tavus Rose, of Berlin ; Haidinger, of Edinburgh. 

Jan. 7, 1828. — According to the rules, the Academy proceeded 
to the election of a Vice-President. M. Mirbel had a majority of 
votes. — Mr. Warden communicated a letter from Mr. Smith, who, 
towards the end of 1826, explored a country hitherto unknown, to 
the S.W. and E. of the Rocky Mountains — M.Thomas Grillon an- 
nounced his discovery of a new mechanical means for moving vessels. 
— M. Blainville read a notice respecting the difference of the males 
and females of a species of gelasin. — M. Gannal read a memoir On 
the inspiration of chlorine in consumption. — Mr. Ivory was elected a 
Corresponding Member in the Section of Geometry. — M. Becquerel 
read a memoir On the electrical properties of the tourmaline. — 
M. Duvau read a statistical essay On the department of Indre and 
Loire. 

Jan. 14. — M. Biot read a memoir On double refraction. On this 
occasion a sealed packet deposited by him on the 7th of January 
1822, was given up to him ; it contained a paper intitled, Deter- 
mination experimental des expressions des deux vitesses dans les phe- 
nomenes de la double refraction. — A secret committee from the 
Section of Chemistry presented the following list of candidates for 
the vacant place of Corresponding Member : MM. Arfwedson, of 
Stockholm ; Henry Rose, of Berlin ; Thomson, of Glasgow ; Houtou 
Labillardiere, of Rouen ; Liebig, of Giessen ; Brande, of London. 

Jan. 



Intelligence and Miscellaneous Articles, 141 

Jan. 22.— M. Arago communicated a letter from Mr. Dalton on 
the aurora borealis of the 29th of March 1826 ; and a memoir by- 
Mr. Scoresby On the singular effects produced by lightning on the 
vessel called the New York. He also gave a verbal account of an im- 
portant memoir by M. Savary On magnetizing by the electric spark. 
— M. Legendre added fresh details to those which had been pre- 
viously given onthe interesting analytical researches of M. Jacobi 
of Kcenigsberg.— M. Cauchy presented a memoir On the remain- 
ders of functions expressed by definite integrals. — M. Dupin read 
a notice respecting early instruction at Touraine. — Mr. Warden 
communicated a letter relating to some islands recently discovered 
by Captain Coffin, not far from the coast of Brazil. — M. Arfwed- 
son received the greatest number of votes as a corresponding mem- 
ber of the Section of Chemistry. — The members elected by ballot 
to constitute Commissions for the adjudging of prizes this year, 
are; For the mathematical prize relating to the resistance of fluids: 
MM. Lacroix, Legendre, Poisson, Fourier, and Prony.: — For the 
astronomical prize : MM. Arago, Mathieu, Lalande, Bouvard, and 
Damoiseau. — For the prize relating to statistics : MM. Coquebert, 
Fourier, Dupin, Andreossy, and Lacroix. 

Jan. 28. — There were read, a letter addressed to M. Delessert, con- 
taining information respecting M. Bonpland ; A letter from MM. 
Quoy and Gaimard, containing geological observations ; A letter from 
M. Valz, of Nimes, On the elements of the two last comets. — After 
a report by M. Navier, a memoir presented by M. Landormy, On 
the theory of flying, was not approved of; this was also the case 
with M. Joseph Anastasi's project for towing. — M. Quenot read a 
memoir On a wire suspension-bridge, constructed at Jarnac, over the 
Charente. — M.Geoffroy Saint-Hilaire read a memoir On two species 
of animals, named Trochilos and Bdella by Herodotus. — The mem- 
bers for the Commission to decide the medical prize are : MM. Ma- 
gendie, Boyer, Dumeril, Portal, Blainville, Fred. Cuvier, Chaptal, 
Dulong, and Gay-Lussac. — Those for the physical prize are : MM. 
Magendie, Mirbel, Desfontaines, Dumeril, and Cuvier. The Com- 
mission for the mechanical prize is composed of MM. Girard, 
Navier, Prony, Molard, and Dupin. 



XXVI. Intelligence and Miscellaneous Articles. 

NEW ASTRONOMICAL EPHEMERIS. 

"Vl/ r E have to congratulate the public on the appearance of one of 
» » the most useful publications in practical astronomy that has 
ever yet been formed. It is an Ephemeris arranged in an entirely 
new manner, computed on an entirely new principle, and adapted to 
the present advanced state of that important science. 

Our readers are aware that, for the last fifty years, the celebrated 
Bode conducted the Berlin Ephemeris with great credit to himself, 
and with great advantage to astronomy. This work, inferior to none 
on the subject, contained annually a vast variety of valuable informa- 
tion, 



142 Iritellikcnce and Miscellaneous Articles. 



•^ 



tion, which would probably have perished, had it not been for the 
interest and zeal that Bode took in every thing relating to astronomy. 
Notwithstanding the rapid strides which the science has made on the 
Continent, little or no alteration however was made in the usual co- 
lumns of this annual publication during Bode's life-time j but on 
his death M. Encke, who has been appointed to succeed him, de- 
termined on re-modelling the work altogether, and on adapting it 
to the increased and increasing demands of the astronomer. With 
this view he has abandoned the plan of publishing the voluminous 
Appendix thereto, which has generally been filled with matter that 
more properly belongs to a periodical journal, and which will now 
be transferred to the pages of Professor Schumacher's very valuable 
Astronomische Nachrichten -, whilst the monthly columns of the Ephe- 
meris will be consequently enlarged without any additional expense 
to the reader. On the other hand, Professor Schumacher will in 
future discontinue his annual Hulfstafeln ; which will henceforth form 
part of M. Encke's work above alluded to. This exchange will be 
highly advantageous to the practical astronomer, who will thus have, 
in one volume, all the daily information he requires for the use of his 
observatory. The present volume is for the year 1830. 

One principal and great improvement in this Ephemeris is the in- 
troduction of mean solar time into all the computations, instead of ap- 
parent time, as hitherto adopted in other ephemerides. The latter is 
never referred to, except in the case of the sun at the time of its cul- 
mination. In every other instance, the places of the moon and planets 
(and even the sun itself) is computed to mean solar time reckoned 
from the apparent equinox. 

The arrangement of the Ephemeris also is very much improved. 
The places of the sun and moon are, as usual, disposed in monthly 
columns : but the places of the planets, and the other subjects which 
compose the body of the Ephemeris, are arranged in their respective 
orders, each by itself ; as will be better understood from the synopsis 
of the work which we are about to present to our readers. 

The computations likewise are carried to a greater degree of mi- 
nuteness than has hitherto been done in any other similar work ; and 
are thus not only better adapted to the more refined wants of the 
modern astronomer, but also more convenient for interpolation. 

On the whole it is a work which we are persuaded will find a place 
in every observatory. We have often expressed our opinion of the 
want of such an Ephemeris, having occasionally suggested improve- 
ments for our own national production " the Nautical Almanac ." 
and we know that for many years past repeated representations on 
the same subject have been made to the Board of Longitude, not 
only by private individuals, but also by the Royal Society j but all to 
little or no purpose. For, though a gleam of light had lately begun 
to flitter amongst that learned body (like the expiring flame of a 
lamp), and they consequently thought it right (unconscious however 
of their approaching dissolution) to listen at last to the increasing 
demands of the astronomer -, yet they were so tardy in their produc- 
tion, and so sparing in their explanations, that the information they 

intended 



Intelligence and Miscellaneous Articles. 143 

intended to give was more speedily and better supplied from a foreign 
source. 

The present, however, forms a new aera in the science j and some- 
thing may now perhaps be done to place astronomy (as it ought to 
be) on a better footing in this country. And since oeconomy is the 
order of the day, and has in fact been publicly declared to be one of 
the causes of the dissolution of the Board of Longitude, we would 
propose to follow up that system, by getting rid also of the whole of 
the expense incurred in forming the Nautical Almanac, and placing 
it in totally different hands. For, the computers of the Berlin Ephe- 
meris would (no doubt) for a small additional sum, be very readily 
induced to adapt their calculations to the meridian of Greenwich : 
and any respectable booksellers, or other body of men in this country, 
if the copyright of such work were secured to them, would not only 
very readily defray that additional sum, and the expenses of printing, 
for the privilege thus conferred on them, but also employ an English 
computer to revise the calculations. The astronomer would thus 
be furnished with a work more fitted for his purpose, and the public 
be relieved of a considerable expense, which, after all, has hitherto 
produced only a secondary sort of Ephemeris*. 

We come now, however, to a more minute account of the work in 
question, which is as follows. The ephemeris of the sun is for each 
month divided into two pages ; one of which is devoted to apparent 
noon, and the other to mean noon. The former page contains, besides 
the days of the month and the days of the week, the mean time (to 
two places of decimals in the seconds), the right ascension of the sun 
(to two places of decimals), and its declination (to one place of de- 
cimals), together with the equation of time (to two places of decimals), 
and the logarithm of the double daily variation in the declination, — a 
quantity extremely useful in determining the time from altitudes of 
the sun. The latter page contains the right ascension of the meridian 
(to two places of decimals), the longitude of the sun (to one place of 
decimals), its latitude (to two places of decimals), the logarithm of the 
radius vector (to seven places of decimals), and the semi-diameter of 
the sun (to two places of decimals) -, together with not only the days 
of the month, but likewise the number of days elapsed from the com- 
mencement of the year. 

The ephemeris of the moon is also divided into two parts ; but as 
the computations are made for every twelve hours, each month occu- 
pies four pages. These contain the moon's longitude, latitude, right- 
ascension, declination, parallax, and semi-diameter, (each to one 

* If the Nautical Almanac were made what it ought to be, and such as 
the situation of this country demands, we have no doubt but that its sale 
might be considerably increased. We know that the American booksellers 
(who reprint that work in the United States) correspond with the German 
astronomers for the supply of additional matter, to be inserted in the 
annual volumes. And what is the consequence ? One bookseller alone 
(and there are several who reprint the work) sells upwards of twelve thou- 
sand copies ! We believe the total sale of the Nautical Almanac, in this 
country, never amounted to seven thousand copies. 

place 



144 Intelligence and Miscellaneous Articles, 

place of decimals,) for mean noon, and mean midnight. There is also 
given the mean time of the moon's upper and lower culmination, (to 
the tenth of a minute in time), as well as her right ascension and de- 
clination (to the tenth of a minute in space) ; together with the time 
of her rising and setting, the time of her changes, and the time when 
she is in perigee or apogee. > 

At the end of this joint ephemeris of the sun and moon, there is 
given for every tenth day of the year, the apparent obliquity of the 
ecliptic, the parallax of the sun, the aberration, and the equation of 
the equinoctial points (each to two places of decimals) ; together with 
the place of the moon's node (to the nearest tenth of a minute). 

Then follows an ephemeris of each of the planets, including the 
four newly discovered ones. The places of Mercury and Venus are 
computed for mean time at noon for every second day, and the re- 
maining planets for mean time at midnight for every fourth day of 
the year. The columns contain the heliocentric longitude and lati- 
tude of the seven principal planets (to one place of decimals in the 
seconds), the geocentric right ascension (to two places of decimals), 
and the geocentric declination (to one place of decimals) j the radius 
vector, and the logarithm of the distance from the earth (each to seven, 
places of decimals) ; together with the time of their rising, setting, 
and passing the meridian. The computations of the four newly dis- 
covered planets are not so minute, except at the time of their oppo- 
sition 3 for which period a separate ephemeris is given of the position 
of the planet for every day. 

We have next an ephemeris of the time of the eclipses of Jupiter's 
satellites (to one place of decimals) -, to which is subjoined (for each 
satellite) a table for computing with the greatest accuracy, not only 
the configurations at any moment, but also the position of the satellite 
with respect to Jupiter at the time of its immersion or emersion. At 
the end of these tables, we are presented with another ephemeris 
(computed for every fortieth day) of the apparent position and mag- 
nitude of Saturn's ring. 

After this comes a table of the mean places (for 1830) of 45 prin- 
cipal stars 5 the right ascensions to three places of decimals, and the 
declinations to two places of decimals. From these are computed and 
given for every tenth day of the year, the apparent places of the same 
stars (to two places of decimals), with their differences. And we have 
also the apparent places, for every day in the year, of a and $ Ursce 
Minoris. To the whole of which are annexed formulae for determining 
the amount of the diurnal aberration. Following these is given a 
table of the constants A, B, C, D, for every tenth day of the year, for 
the purpose of determining the apparent places of any other stars. 
It should however be remarked, that these letters do not indicate 
precisely the same quantities as are so designated in the catalogue of 
the Astronomical Society : and it should also be noted that the num- 
bers are adapted to sidereal time. There is however another table 
subjoined, for the use of those who are disposed to adopt mean solar 
time in these computations. 

Next follows a particular account of all the solar and lunar eclipses 

that 



Intelligence and Miscellaneous Articles. 145 

that will happen in the course of the year j together with all the ne- 
cessary elements for computing them. This is followed by three pages 
of the principal phaenomena of the planets : such as the time of their 
perigee or apogee, their perihelion or aphelion, their greatest elon- 
gation, their greatest latitude, their conjunction and opposition, their 
passing the nodes, their greatest brilliancy, their proximity to the 
moon and occultation thereby, &c. 

Then follows a list of moon-culminating stars, occupying seventeen 
pages ; and (which is equally valuable,) a list of the occultations of 
all the stars down to the 7th magnitude inclusive, that will take place 
in the course of the year ; wherein the mean time of the immersion 
and emersion of the star (to the nearest tenth of a minute) is given, 
as well as the angle from the vertex of the moon at which the phe- 
nomenon will take place. To this list is subjoined some auxiliary 
tables for computing the occultation more minutely, if required. 

To the whole is annexed an Appendix, giving an account of the 
mode in which all the computations are made, and the tables from 
which they are derived. By this excellent plan, the observer Can at 
any time verify any of the calculations, and detect any error which he 
may have cause to suspect. The names of the computers also are 
given, which must materially tend to insure the accuracy of the work. 

Such is the substance of the publication now before us, which has 
just reached this country, and which does so much credit to its di- 
stinguished conductor. We hail it as the harbinger of a general im- 
provement in the mode of arranging and forming the ephemerides of 
different nations. And although it is mortifying to reflect that this 
country cannot (or will not) maintain its pre-eminence in these and 
other scientific subjects, yet we are grateful for information wherever 
it can be found, and trust that we shall be able eventually to emulate 
the splendid example which has thus been set us. M. Encke, disdain- 
ing the trammels of former and less enlightened times, and relying 
on his own excellent judgement and abilities, has nobly and boldly 
struck out a new path for himself, which we have no doubt will soon 
be followed by every nation pretending to encourage the science of 
astronomy. , 

We propose to give, in a subsequent Number of our Journal, a 
translation of the Appendix above alluded to, which will enable the 
English reader to make use of this most excellent Ephemeris ; since 
a very minute account is there given of the mode in which the dif- 
ferent tabular values are formed. There will then be nothing left for 
explanation but the headings of the different columns j which are in 
most cases so much like the English names, that little difficulty will 
occur in understanding them. 



IMPROVED AIR-PUMP. BY MR. JOHN DUNN, OPTICIAN, EDIN- 
BURGH. 

In the course of my business, having often heard it regretted that 
the cost of apparatus prevented many gentlemen from engaging in 
philosophical pursuits, I have made it my study to simplify the con- 

New Series. Vol. 4. No. 20. Aug. 1828. U struction 



146 



Intelligence and Miscellaneous Articles. 



struction of those which I have been employed to make, wherever this 
could be done without impairing the accuracy of their performance. 

One of my first efforts was directed to that most valuable instru- 
ment the air-pump, which 1 shall endeavour to show I have improved 
so veiy materially, as to be able to furnish one capable of effecting as 
complete an exhaustion as the most perfect form of the instrument 
hitherto devised, and, at the same time, nearly as simple and as cheap 
as its most imperfect form. I mentioned my views on the subject to 
several gentlemen qualified to judge of their correctness, and soon had 
an opportunity of putting them to the test of experiment. I received 
an order to make one for Mr. Lees, lecturer on mechanical philosophy 
in the School of Arts here, on condition that he was to be permitted 
to return it, if, on trial, it was not found capable of executing all 
that I had led him to expect. This pump, through the kindness of 
Mr. Lees, in whose possession it has been for the last eighteen months, 
was exhibited to the Society for the Improvement of the Useful Arts, 
on the 19th of December 1827 *. 

Believing the only useful part of Cuthbertson's improvement of the 
air-pump to be the contrivance for opening the valves at the bottoms 
of the barrels, mechanically, I was of opinion a pump would perform 
nearly, or altogether as well, divested of all the other peculiarities of 
his instrument, and possessing the decided advantages of being cheaper 
and much more easily kept in order. 

The Figure is a section of one of the 
barrels of my pump, in which I employ 
metallic valves v v' at the bottom of the 
barrels, and waxed silk ones S S' in the 
pistons, laying aside Cuthbertson's me- 
tallic valves in the pistons, removing all 
his apparatus from the top of the barrels, 
and leaving the pistons exposed to the 
atmosphere^ as 1 consider all those con- 
trivances to be unnecessary, although 
it has been uniformly held essential to 
a good air-pump, since the time of 
Smeaton's invention, that the pressure 
of the atmosphere should be taken off 
the piston-valves ; and my reason for 
doing so is, that the air will be always 
so compressed in the barrels, by the descent of the pistons, as of itself 
to have sufficient elastic force to open the silk valves in the pistons, 
the capacity of the barrels being each several thousand times greater 
than the space between the two valves, when the piston is at the 
bottom. In fact, by making the under side of the piston and the 
bottom of the barrel fit each other, which, with the assistance of the 




* The instrument had been previously submitted to the examination of 
Dr. Turner, one of the Secretaries of the Society of Arts, who reported that 
he had minutely examined it, and was perfectly satisfied with its performance. 
On his representation to the Council of the London University, I have since 
received an order to make one for the chemical class of that Institution. 

oil 



Intelligence and Miscellaneous Articles. 147 



r> 



oil employed in the barrels may be done perfectly, there will be no 
space left but the small hole in the piston leading to its valve. 

For illustration, let us suppose the stroke to be 12 inches, and the 
diameter of the barrels 2\ inches, or 25 tenths (as is the case in 
Mr. Lees' pump), the diameter of the hole e one-tenth of an inch, and 
ks length 1 inch, then, circles being to each other as the squares of 
their diameters, we have 1 x 1 = 1 for the capacity of the hole, and 
25 x 25 x 12 = 7500 for the capacity of the barrels ; and conse- 
quently air, which in the receiver was 7000 times rarer than the at- 
mosphere, would have sufficient elastic force to open the valve in the 
piston ; but as this is a degree of rarefaction far beyond what has ever 
been attained, or even expected, it follows that any greater nicety of 
construction here is unnecessary. 

The above plan may, however, be objected to, on account of its 
still leaving something to depend on the elastic force of the air which, 
should any one consider desirable to be removed, can be done by 
adopting metallic valves I V * with projecting points p' p', to strike 
against the bottom of the barrels, having the spaces O' T, OT, filled 
with oil, to exclude the external air during their shutting, instead of 
the oiled silk ones S S' ; but even this small addition I consider 
wholly unnecessary. — Edin. New Phil. Journ. 



GALLATES OF QUINA AND CINCHONIA. 

M. Platania forms these compounds in the following way : Pour an 
infusion of galls into a hot solution of sulphate of quina, wash the 
precipitate with cold water upon a filter, and dry it at 100° of Fahr. 
Afterwards dissolve it in warm alcohol ; pour off the solution and 
evaporate it, then add cold water to it, which precipitates pure gal- 
late of quina. 

Another process consists in pouring gallic acid into sulphate of 
quina, and merely washing the precipitate with cold water j and it 
may also be formed by directly combining the acid and base each 
separately dissolved in alcohol. Gallate of quina is very white and 
light ; its sp. gr. is 0-816 at 60° Fahr. Its vapour is astringent, and 
very slightly bitter j it is soluble in alcohol and aether, but almost 
insoluble in water. It is composed of nearly 

Gallic acid 14-87 

Quina 85-13 

100-00 
The gallate of cinchonia is obtained by dropping gallic acid into 
a solution of cinchonia ; the gallate precipitates, and is to be re- 
dissolved in water and suffered to cool ; the liquid becomes opale- 
scent, and deposits granular transparent crystals. — Hensmaris Re-> 
jiertoire de Chimie, fyc. Jan. J828. 



PREPARATION AND PROPERTIES OF ALUMINUM. 

On these subjects the following statements are made by M.Woeh- 

* The accented letters refer to a suppressed figure of the other barrel 
of the pump. 

U2 ler. 



148 Intelligence and Miscellaneous Articles. 



r e 



ler. The method of preparing aluminum is founded upon the in- 
oxidability of this metal by water. When an attempt is made to 
heat chloride of aluminum with potassium in a tube, the action is so 
strong and the extrication of heat is so considerable, that the appa- 
ratus is instantly broken. I therefore employed a small platina 
crucible, the cover of which was kept on by a wire of the same me- 
tal. At the moment of reduction, the crucible became intensely red- 
hot, both within and without, although it was but slightly heated ; 
the metal of the crucible was not sensibly acted upon. The opera- 
tion may also be effected in a porcelain crucible with a cover at- 
tached. Some small pieces of potassium of about the size of a pea, 
and not more than ten at once, are placed in the crucible, and 
upon them are put an equal number of pieces of chloride of alu- 
minum of the same size; the crucible is to be heated with the spirit- 
lamp, at first gently, and afterwards more strongly, and until the 
spontaneous incandescence of the matter ceases. Excess of potas- 
sium is to be avoided ; for after it was oxidized, it would dissolve a 
portion of the aluminum. The reduced mass is generally completely 
fused, and is of a blackish-gray colour. When all is cold, the cru- 
cible is to be thrown into a large vessel of water; a gray powder is 
soon deposited, which, when looked at in the sunshine, appears to be 
entirely composed of small metallic plates ; the powder is to be 
washed with cold water and then dried : it is the metal of alumina. 

Aluminum somewhat resembles platina in powder. I discovered 
some scaly coherent particles, which had the colour and splendour 
of tin. Under the burnisher it readily assumes the appearance of this 
metal; rubbed in an agate mortar, it seems to be a little compres- 
sible, and unites into larger scales, with a metallic lustre ; and it 
leaves in the mortar traces of a metallic appearance. When heated 
in the air, until it is ignited, it inflames and burns with great ra- 
pidity ; the product is the white oxide of aluminum in a hard mass. 
Reduced to powder and blown upon in the flame of a candle, each 
particle suddenly becomes an inflamed point, the splendour of which 
is not less than that of the sparks of iron burning in oxygen gas. 
In pure oxygen gas aluminum burns with so dazzling a light, that 
the eyes can scarcely bear it ; the heat generated is so considerable, 
that the oxide produced is partly fused. The particles which have 
been fused are yellowish, and as hard as corundum; they do not 
merely scratch, but they cut glass. In order that aluminum may 
burn in oxygen gas it must be heated to redness. 

Aluminum is not oxidized by water, and this fluid may sponta- 
neously evaporate from the metal without its being in the least tar- 
nished ; when however the water is nearly at its boiling point, the 
metal is slowly oxidized, and hydrogen is liberated. 

The sulphuric and nitric acids when cold do not act upon alumi- 
num ; when heated, concentrated sulphuric acid readily dissolves it, 
and without the evolution of sulphurous acid; the sulphuric solution 
did not by evaporation give the smallest crystal of alum. 

Aluminum introduced into a solution of caustic potash, even when 
weak, dissolves readily, and with the evolution of hydrogen; the so- 
lution 



Intelligence and Miscellaneous Articles. 149 

lution is perfectly clear; the same solution takes place in ammonia; 
and it is surprising to observe how much of this earth the ammonia 
is capable of uniting with : the evolution of hydrogen is similar to 
that with potash. When aluminum is heated to dull redness, and 
exposed to a current of chlorine, it inflames and is converted into 
chloride, which sublimes as fast as it is formed. — Ibid. 

CHLORIDE AND OTHER COMPOUNDS OF ALUMINUM. 

M. Woehler obtains chloride of aluminum, for the purpose of 
procuring the metal from it, by the following process : alumina pre- 
cipitated by excess of carbonate of potash, was well washed and 
dried, and then made into a thick paste with powdered charcoal, 
sugar and oil ; this paste was then heated in a covered crucible until 
all the organic matter was destroyed. By these means any sub- 
stance is mixed very intimately with carbon : the product while it 
was hot, was put into and made to. fill a porcelain tube, which was 
placed in a furnace of an oblong form. One end of the tube was 
connected with another tube containing fused chloride of calcium, 
and this with an apparatus for the evolution of chlorine ; the other 
end of the tube opened into a small tubulated receiver, provided 
with a conducting tube. When the apparatus was full of chlorine, 
the tube and its contents were made red-hot. The chloride of alu- 
minum was readily formed ; a smal* portion was carried over with 
oxide of carbon, which fumed strongly on coming into contact with 
the air. The chlorine was long retained by the mass of matter. 
The receiver contained chloride of aluminum in the state of pow- 
der. After an hour and a half the chloride obstructed the end 
of the tube (though an inch in diameter) which passed into the re- 
ceiver ; this caused the stoppage of the process. 

On taking the apparatus to pieces, it was found that all that part 
of the tube which passed through the furnace was filled with chlo- 
ride of aluminum, and it weighed more than an ounce. It con- 
sisted partly of an aggregation of long crystals, and partly of a 
firm mass, which was readily detached from the tube, and was of a 
pale yellowish-green colour, semitransparent, and of a lamellated and 
distinctly crystalline texture ; but no crystal could be found suffi- 
ciently regular to admit of its form being ascertained. When brought 
into contact with the air, it fumed feebly, gave a smell of muriatic 
acid, and soon became a transparent fluid. W T hen thrown into wa- 
ter, it dissolved with strong hissing, accompanied with so much 
heat, that the fluid, when the quantity is small, boils rapidly : ac- 
cording to M. Oersted, the temperature is not much higher than 
that of boiling water. Its fusing and vaporizing points seem to be 
the same. Chloride of aluminum may be preserved without any 
alteration in naptha ; when heated with this oil it liquefies, and sinks 
to the bottom of the vessel, in the form of a reddish-brown liquid, 
upon which potassium exerts no action. Chloride of boron may 
be obtained by passing chlorine over calcined borax heated to red- 
ness. 

Sulphuret of Aluminum, — When sulphur is suffered to drop upon 

aluminum 



1 50 Intelligence anil Miscellaneous Articles, 



•a 



aluminum in a state of vivid ignition, the mixture becomes strongly- 
incandescent, and a black frit is formed: it is semimetallic in ap- 
pearance, and when polished is of a shining iron-black colour. When 
exposed to the air, this frit emits a smell of sulphuretted hydrogen, 
swells, and falls into a grayish-white powder ; when applied to the 
tongue, it occasions a hot penetrating sensation ; when thrown into 
water, it is converted into a gray powder of alumina, accompanied 
with a rapid disengagement of sulphuretted hydrogen. Sulphate of 
alumina when heated to redness in contact with hydrogen, loses its 
acid, but the earth is not reduced. 

Sulphuretted Hydrogen and Aluminum, — When chloride of alu- 
minum is sublimed in a small retort, and a strong current of sul- 
phuretted hydrogen gas is at the same time made to enter its neck, 
it is absorbed ; and a very white sublimate is formed, partly in the 
state of pearly transparent scaly crystals, and partly in that of a 
brittle mass. The residuum of sulphuretted hydrogen was dis- 
placed from the apparatus by simple hydrogen. In the cold, this 
gas is not absorbed by the chloride of aluminum. In contact with 
the air, the sublimed matter moistens rapidly, sulphuretted hydro- 
gen is disengaged, and chloride of aluminum remains in solution. 
When sublimed in a tube, it evaporates with the evolution of sul- 
phuretted hydrogen equal to from 30 to 40 times its volume, which 
however cannot be the whole of the gas, because the combination is 
formed at a high temperature. W T hen put into water, the sublimate 
is decomposed with the same violence as the pure chloride; much 
sulphuretted hydrogen is disengaged, and the solution is rendered 
turbid by the precipitation of sulphur. Pass a small piece of the 
compound into a tube full of mercury, and afterwards some water ; 
a great volume of gas is evolved with great rapidity, which is com- 
pletely absorbed by solution of acetate of lead, with the precipita- 
tion ofsulphuret; when thrown into solution of ammonia, alumina 
is precipitated. No action takes place between the compound of 
sulphuretted hydrogen and aluminum with muriatic acid gas. 

Phosphuret of Aluminum. — Aluminum heated to redness in the 
vapour of phosphorus, combines with it with vivid inflammation ; 
the product is a blackish-gray pulverulent substance, which under 
the burnisher assumes a deep gray metallic lustre, and exhales a 
smell of phosphuretted hydrogen ; when thrown into water, it occa- 
sions the evolution of phosphuretted hydrogen, which is not spon- 
taneously inflammable. In the cold> the disengagement of this gas 
is not so rapid as that of sulphuretted hydrogen, but it is quickened 
by heat. 

Seleniuret of Aluminum. — Selenium when mixed with the metal 
of alumina, and heated to redness, combines with it, producing 
strong inflammation. The seleniuret thus obtained is a black pow- 
der, which being rubbed becomes of a dull metallic aspect. When 
exposed to the air it continually exhales a smell of seleniuretted 
hydrogen ; in water the disengagement of this gas. is very 'rapid, 
and the water is quickly reddened by a portion of precipitated se- 
lenium. 

Arseniuret 



Intelligence and Miscellaneous Articles. J 51 

Arseniuret of Aluminum. — Arsenic reduced to powder and heated 
to redness with aluminum, combines with it ; the inflammation is less 
vivid than with the preceding combustibles. The compound is a 
powder of a deep gray colour, which by rubbing acquires a dull 
metallic appearance, and when exposed to the air it exhales a faint 
smell of arseniuretted hydrogen ; when cold, the disengagement is 
slow, b.ut it is much accelerated by heat. 

Telluret of Aluminum. — When the powder of tellurium was put 
into a tube with aluminum, much heat was excited, and the mixture 
was thrown with explosion out of the tube ; this inconvenience is 
avoided by not powdering the tellurium. The product is a metal- 
line, brittle, black frit, which when exposed to the air emits an in- 
tolerable odour of telluretted hydrogen ; and when thrown into wa- 
ter it evolves the same gas with rapidity : the water at first be- 
comes of a red colour, afterwards brown, and eventually opake, on 
account of the interposed reduced tellurium: the telluret of alu- 
minum appears to decompose in water with much greater facility 
than the sulphuret of the same metal. — Ibid. 

NATIVE IODIDE OF MERCURY. 

M. Del Rio has already mentioned that he has discovered iodide 
of silver in America, and he has mentioned its locality. He has 
since discovered another iodide ; and he is of opinion that the metal 
in combination with it is mercury. It perfectly resembles dark- 
coloured cinnabar, except that its colour is deeper and its streak 
paler ; it is however certain, that it accompanies an earthy iodide, 
which M. Del Rio believes to be the metal of magnesia mineralized 
by iodine. — Ibid. 

CORYDALIN, A NEW VEGETABLE ALKALI. 

According to M.Wackenroder, this alkali is contained in the root 
of the fumitory (not the common fumitory, fumaria officinalis, but 
the fumaria cava, and corydalis tuberosa of Decandolle). The dry 
root is to be coarsely powdered and digested for some days in wa- 
ter ; filter the infusion, and precipitate with excess of potash ; dry 
the precipitate and treat it with boiling alcohol, until it ceases to 
dissolve anything. It sometimes happens that during the cooling 
of the alcohol, crystals of corydalin are deposited. The solution is 
to be evaporated to dryness, and the residuum is to be dissolved in 
weak sulphuric acid; this solution is then to be decomposed by an 
alkali either caustic or carbonated. A white deposit is formed, 
which by drying becomes of a light gray colour. 

Dry corydalin soils the fingers very much ; it is insipid and inodo- 
rous. It is soluble in alcohol ; and this solution when hot and saturated 
deposits colourless prismatic crystals of a line in length. By slow 
Spontaneous evaporation, fine laminae are formed. The solution 
acts as an alkali upon vegetable blue colours. At a temperature 
below that of boiling water, it melts into a deep green-coloured 
fluid, which, when solidified, has a crystalline texture, and is trans- 
parent in thin laminae. At a higher temperature it yields water and 

ammonia, 



152 Intelligence and Miscellaneous Articles, 



T6 



ammonia, and is converted into a transparent brown mass. iEther 
dissolves corydalin with the same facility as alcohol; caustic potash 
dissolves it in considerable quantity. 

This alkali forms extremely bitter salts with acids ; sulphuric acid 
forms two different salts ; one which crystallizes is obtained when 
the acid is digested with excess of base ; the solution is to be filtered 
and evaporated : the product is very slightly soluble in water. When 
a small quantity of sulphuric acid is added to a solution of corydalin 
in alcohol, so as not to saturate the base perfectly, a portion of 
crystalline matter is deposited; and there remains a stratum of a 
greenish transparent substance, which is unalterable by exposure to 
the air, and readily soluble in water : the solution reddens litmus 
paper slightly ; an excess of acid renders it purple, and eventually 
blackens it. Nitric acid when diluted and cold dissolves and 
forms a colourless solution with corydalin ; but when heated it be- 
comes of a red colour, which, when the solution is concentrated, be- 
comes of a blood-red colour. This action is so strong, that by the 
aid of heat the smallest quantity of corydalin may be discovered in 
a fluid. Muriatic acid forms with this alkali an uncrystallizable 
salt; acetic acid is still more difficult of combination with it than 
sulphuric acid ; but it forms a crystalline salt, which may be redis- 
solved a second time in water and crystallized. Tannin is one of 
the most sensible tests of corydalin, as for all other vegetable bases. 
The precipitate is white when the solution is dilute, and grayish- 
yellow if concentrated. — Ibid. 

ACTION OF ALKALIES AND THEIR CARBONATES, &C. ON IODIDES. 

M. Berthemot, having made numerous experiments on the action 
of alkalies, and some metals on the iodides, concludes : — That the 
earthy oxides and their carbonates do not act upon iodide of mercury ; 
— that potash, soda, barytes and strontia, decompose iodide of mer- 
cury by the intervention of water or alcohol, and there result oxide 
of mercury and tri-iodo-hydrargyrate of potash, which on the cooling 
of the liquors, successively deposit iodide of mercury, and bi-iodo- 
hydrargyrate of potash ; — that lime produces the same phenomena, 
with this difference however, that the action occurs only by the inter- 
vention of alcohol ; — that the soluble carbonates of the alkaline oxides 
also decompose iodide of mercury, and yield analogous products, but 
only with the intervention of alcohol ; — that the insoluble carbonates 
of the alkaline oxides do not act upon iodide of mercury, either by the 
intervention of water or alcohol 3 — that the protoxide of mercury de- 
composes the iodide of potassium, forming potash, and metallic mer- 
cury, or protiodide of mercury and iodo-hydrargyrate of potash ; — 
that the remaining alkaline iodides have a similar action, except that 
of calcium, which does not appear susceptible of it ; — that peroxide 
of mercury decomposes the alkaline iodides, forming an alkaline oxide 
and bi-iodo-hydrargyrate. — Journal de Pharmacie, April 1828. 

CITRIC ACID FROM GOOSEBERRIES. 

M. Tilloy, by the annexed process, has prepared citric acid from 

gooseberries, 



Intelligence and Miscellaneous Articles, 153 

gooseberries, so as to be able to obtain it for 12 francs, 96 centimes 
the kilogramme j whereas the price of citric acid in France is from 
29 to 30 francs for the same weight. 

The gooseberries are to be bruised and fermented ; the alcohol is 
to be separated by distillation ; the residuum is to be pressed to ex- 
tract the whole of the liquid. To this liquor, while hot, carbonate of 
lime is to be added as long as effervescence takes place : after standing, 
the citrate of lime is to be collected and suffered to drain j it is to be 
repeatedly washed and then pressed. The citrate of lime thus ob- 
tained, being still coloured and mixed with malate of lime, is to be 
mixed with water to the consistence of a thin syrup, and is then, 
while hot, decomposed with sulphuric acid, diluted with twice its 
weight of water. The liquor resulting from this operation, is a mix- 
ture of sulphuric (malic ?) and citric acid, and is to be again treated 
with carbonate of lime. The precipitate, when collected on a filter, 
is to be plentifully washed, pressed, and again mixed with sulphuric 
acid j the clear liquor, containing the acid, is to be decolorized by 
animal charcoal, and evaporated. When it is sufficiently concen- 
trated, it is suffered to deposit, and the clear liquor poured off is put 
into stoves heated from 20° to 25° Centig. Coloured crystals are 
thus obtained, which are to be drained, slightly washed, and recry- 
stallized.— Ibid. 

SOLANINE. 

M. Pelletier could not obtain solanine from the solatia of Europe, 
but he procured it from the solarium mammosum of the Antilles. — 

Ibid, May 1828. 

BLUE COLOUR BY THE ACTION OF MURIATIC ACID UPON ALBU- 

• 'MEN. 

Various unsuccessful experiments appear to have been made to 
produce this blue colour j first observed, we believe, by M.Caventou. 
According to M. Robiquet, the more acid employed, the more readily 
is the blue colour produced, to a certain extent. He finds that seven 
or eight parts of acid, to one part of albumen, yield the most intense 
blue, even at a low temperature j but its development is favoured by 
a temperature of 25° to 30° Centig. — Ibid. 



BOTRYOGENE, OR NATIVE RED IRON-VITRIOL Of FAHLUN. 

Berzelius gave an analysis of this salt some time since j of its phy- 
sical properties very little was however then known. Mr. Haidinger, 
having been furnished with specimens by Berzelius, and M. Pohlhei- 
mer of Fahlun, has given an account of its crystalline form and quali- 
ties in Brewster's Journal for July last. 

It occurs in the great copper-mine at Fahlun in Sweden. The 
regular forms of botryogene belong to the hemiprismatic system of 
Mohs j they are in general pretty distinct, but too imperfectly formed 
to permit any thing more than an approximation to the real angles 
within ten minutes of a degree. The lustre of botryogene is vitreous. 
It is translucent. Its colour is a deep hyacinth-red j which, how- 
ever, in compound massive varieties, passes into ochre-yellow, which 
is likewise the colour of the streak. It is sectile, and becomes a little 

New Series. Vol. 4. No. 20. Aug. 1828. X shining 



154 Intelligence and Miscellaneous Articles. 



't-> 



shining in the streak, and its hardness is a little inferior to that of 
alum. Its specific gravity is 2*039. It is slowly soluble in water, 
and does not, therefore, possess so powerful an astringent taste as 
common sulphate of iron. The crystals are not above two lines in 
length, and are usually aggregated in reniform and botryoidal shapes, 
consisting of globules with a crystalline surface ; the trivial name al- 
ludes to the tendency of the salt to produce such imitative shapes. 

When exposed to a moist atmosphere, it becomes covered with a 
dirty yellowish powder, but remains unchanged in a dry atmosphere : 
before the blowpipe it intumesces, and gives off water in a glass tube, 
eaving a reddish yellow earth behind, which according to the flame 
employed may be changed into protoxide or peroxide of iron. With 
salt of phosphorus it yields a red glass, which loses its colour on cool- 
ing. Boiling water dissolves part of it, leaving a yellow ochre, which 
therefore is an integral portion of the mixture. The solution, nitric 
acid being added to it, may be precipitated by muriate of barytes, 
but not by nitrate of silver. Ammonia, with which the salt is digested 
in a stoppered bottle, takes away all the acid, and leaves the iron in 
the shape of a slightly greenish black powder. The iron therefore is 
contained in the salt, not as a pure oxide, but as a compound of the 
protoxide and peroxide, which is black when pure, and produces red 
solutions. 

The following are the results of three analyses : 

I. II. III. 

Persulphate of iron, with excess of base, 677 6*85 *) 
Bisulphate of the protoxide and perox- > 48*3 

ideofiron 35'85 39'92j 

Sulphate of magnesia 26-88 1 7' 1 20*8 

Sulphate of lime 222 671 0-0 

Water and loss 28'28 31-42 30-9 

The second analysis is most correct as to the water. Berzelius con- 
siders all the substances mixed with salt of iron as foreign to the salt, 
and uncombined with it. 

ERINITE, A NEW MINERAL SPECIES. 

This substance is arseniate of copper, contained- in Mr. Allan's 
cabinet. Mr. Haidinger makes the following observations on it. 
" Though not presenting determinable crystals, the appearance of 
the specimens in Mr. Allan's cabinet, the only ones which I re- 
member to have ever met with, are highly crystalline. The indivi- 
duals are arranged in concentric coats with rough surfaces, produced 
by the termination of exceedingly small crystals, the layers often not 
firmly cohering, so that they may be easily separated from each other. 
These layers themselves are very compact -, they show an uneven, or 
sometimes imperfect conchoidal fracture, and traces of cleavage. The 
cleavage probably takes place parallel to the broad faces of rectangu- 
lar four-sided plates, into which the individual terminates. I have, 
in several instances, observed something like them by means of a 
compound microscope, but always very indistinctly. These plates 
form crest-like aggregations. A circumstance which greatly increases 
the difficulty of observing the regular forms, is the complete absence 

of 



Intelligence and Miscellaneous Articles. 155 

of lustre, the surface of the concentric layers being quite dull, while 
there is only a slight degree of resinous lustre on the fracture. 

The colour of erinite is a beautiful emerald-green, slightly inclining 
to grass-green •. the streak, likewise green, is a little paler, and ap- 
proaches to apple-green. It is slightly translucent on the edges. 
The substance of erinite is brittle; its hardness I found = 45... 5*0 
of the scale of Mohs j its specific gravity = 4043. 

According to the locality attached to the specimens in Mr. Allan's 
cabinet, they are natives of the county of Limerick in Ireland. For 
the name of Erinite, which is here proposed for this mineral, the mi- 
neralogical public is indebted to Mr. Allan. It unites, what is rarely 
the case with mineralogical names, the comparatively trite and pro- 
saical allusion to the native country? with the poetical recollection of 
the characteristic verdure of the " Emerald Isle." 

Erinite is associated with two of the species containing arsenic acid 
and copper, described by Count Bournon ; the common arseniate of 
copper (prismatic olive-malachite of Mohs), and the dark blue arse- 
niate, both of them crystallized and disposed between the concentric 
layers of erinite. Dr. Turner gives the following as an approxi- 
mation of the analysis of erinite : — 

Oxide of copper 59*44 

Alumina 1*77 

Arsenic acid 33*78 

Water 501 

100*00 
Brewster's Journal, July 1828. 

ALTERATION OF CRYSTALLINE STATE IN SOLIDS. 

M. Mitscherlich finds that when sulphate of magnesia or sulphate 
of zinc is slowly heated in alcohol, and the heat be gradually increased 
to boiling, the crystals lose their transparency by degrees ; and when 
broken they are found to consist of a great number of new crystals 
entirely different from those of the salt employed, owing to the change 
in the position of the atoms, by internal motion, without the occur- 
rence of solution. Ann. de Chim. xxxvi. p. 206. 

DECOMPOSITION OF AMMONIA BY METALS. 

M. Savart found that 141*91 grains of thin copper wire became 
142*382 grains, or acquired an increase of 0*472 in weight, when 
used for four hours to decompose ammonia : as the wire was in a 
slight degree oxidized, the experiment was repeated ; and when every 
precaution was employed, the increase amounted to -rfr, and 0*105 
of an unknown substance was absorbed by the copper, and its speci- 
fic gravity was diminished from 8*8659 to 7*7919. 

Iron also increases in weight, and diminishes in specific gravity by 
similar treatment, and will strike fire with flint like ordinary steel. 

Ibid, xxxvii. p. 326. 

IODIDES OF CARBON. 

Whilst experimenting for a peculiar purpose, M. Mitscherlich min- 
gled the alcoholic solutions of iodine and soda. " There was formed 

X 2 imme- 



156 Intelligence and Miscellaneous Articles. 



l ir> 



immediately," he observes, " the compound obtained by Serullas. 
But Serullas, to whom we are indebted for a great many interesting 
experiments on this compound, says, that there is formed simultane- 
ously, iodate of soda, iodide of sodium, and hydriodide of carbon j but 
I have not found the slightest trace of iodate of soda. On decom- 
posing the substance obtained by Serullas by means of copper, iron, 
and mercury, I obtained no hydrogen, nor any other kind of gas, but 
only a combination of iodine and carbon. We should therefore con- 
sider this substance as a compound of carbon and iodine formed in 
the following manner : — When the two alcoholic solutions are mixed, 
the iodine combines with the sodium -, and the oxygen set free, unites 
to the hydrogen of the alcohol to form water ; whilst the carbon of 
the alcohol (the latter being considered as a compound of water and 
olefiant gas) combines with another portion of the iodine to produce 
the iodide of carbon. 

" This iodide of carbon, distilled with corrosive sublimate, yields a 
liquid analogous to that which Serullas obtained by employing dry 
chloride of phosphorus. It is also a compound of carbon and iodine ; 
so that we now know two combinations of iodine and carbon, and 
one with carburetted hydrogen, discovered by Faraday, which is dis- 
tinguished from the two others by its chemical properties and crystal- 
line form." 

The experiments of M. Mitscherlich, by showing the true nature 
of M. Serullas' compound, remove the difficulty of supposing that 
two hydriodides of carbon could exist of exactly the same composition, 
but different in properties. 

Ann. de Chun, xxxvii. p. 85. Roy. Inst. Journal, July 1828. 



SOLAR SPOTS. 

The large solar spot, whose appearance we described under our 
last monthly meteorological report, came round on the sun's 
eastern limb in the night of the 12th instant, as we supposed it 
would, and was well-defined by the 14«th, when the nucleus had 
assumed the shape of a pear: on the 17th it was bell-shaped, and 
on the 19th, when nearest to the sun's centre, the umbra and nucleus 
were nearly circular, with a few indentations on the edge of the lat- 
ter, and but little apparent diminution in the size of either since the 
27th of May. At 7 a.m. on the 23rd it was, as nearly as could be 
ascertained from a drawing, in the same position on the sun's disc 
as on the 27th ultimo ; and on the 25th at sunset it was very near 
his lower limb in a very contracted state, resembling a line without 
any perceptible umbra, and went off on his posterior side again in 
the night, making a complete revolution in both cases in 27 days, 
and thus travelling, when the necessary correction is made for the 
earth's annual motion in the ecliptic during the period of its revo- 
lution, at the rate of 1454? miles per hour, which is to the velocity 
of a point on the earth's equator as 7 to 5 nearly. Early in the 
morning of the 19lh, this spot was within 9 degrees of the sun's 
equator, or its declination was 9 degrees North. Its largest dia- 
meter, from a mean of several admeasurements, was 1£ diameter of 

the 



New Patents. 157 

the earth, or about 12000 miles. Although it had undergone con- 
siderable changes in respect to figure, yet it appeared strong enough 
to last another revolution, by which means more favourable oppor- 
tunities may offer to obtain the number of hours (if any) in addi- 
tion to the first observed 27 days of its revolution. It appears from 
a drawing of the positions of this spot, and another large one that 
accompanied it, whose declination was about 19 degrees South, that 
in their daily progress across the sun's disc they moved in slightly 
parallel curved lines from East to West, and went off nearly at the 
same time ; therefore they will probably appear on the sun's eastern 
limb at noon of the 9th of July. Since the 27th of May, consider- 
able variations and alterations have taken place in the positions and 
number of the solar spots ; some have entirely disappeared, while 
new ones have appeared on other parts of the sun's disc. 

LIST OF NEW PATENTS. 

To S. Pratt, of New Bond-street, camp equipage maker, for im- 
provements on elastic beds, cushions, seats, pads, and other articles 
of that kind. — Dated the 25th of June 1 828.-6 months allowed to 
enrol specification. 

To J. Baring, of Broad-street Buildings, merchant, for a new and 
improved mode of making machines for cutting fur from skins for the 
use of hatters. Communicated from abroad.— 3rd of July. — 6 months. 

To J. Johnston Isaac, of Star-street, Edgeware Road, Middlesex, 
for improvements in propelling vessels, boats, &c. — 5th of July. — 
6 months. 

To T. Revis, of Kennington-street, Walworth, Surrey, for an im- 
proved method of lifting weights. — 10th of July. — 6 months. 

To J. Hawks, of Weymouth-street, Portland Place, iron manufac- 
turer, for an improvement in the construction of ships' cable and 
hawser chains. — 10th of July. — 6 months. 

To J. H. A. Gunther, of Camden Town, Middlesex, for improve- 
ments on piano-fortes.— 10th of July. — 2 months. 

To Captain W. Muller, of Doughty-street, Bedford-row, for an 
instrument or apparatus for teaching mathematical geography, astro- 
nomy, and other sciences j and for resolving problems in navigation, 
spherics, and other sciences. — 10th of July. — 6 months. 

To B. Rider, of Redcross-street, Southwark, for his improvements 
in the manufacture of hats. — 17th of July. — 6 months. 

To J. Jones, of Amlwch, Anglesea, for his improvement in certain 
parts of the process of smelting copper ore. — 17th of July. — 6 months. 

*** Mr. Herapath informs us that he has perused a copy of the 
paper written in his defence signed Veritas, and requests us to state to 
our readers, in a form more permanent than a notice on our wrapper, 
that he cannot consider it as intemperate, nor acquiesce in our reasons 
for not inserting it ; and that he conceives the majority of our readers 
would coincide with him in this opinion. He adds that he is ready to 
reply to every point advanced in the papers signed a 0, and F.R.S., 
the names of the writers are commnuicated to him to use in public. 

We 



1 58 Meteorological Observatiojis for June 1 828. 

We must therefore repeat in our justification that we object to con- 
tinue a controversy, when it is degenerating from a philosophical in- 
quiry into a personal dispute. We should not have inserted Mr. H.'s 
last letter, had we observed that, instead of giving any reply to the 
objections brought by a /3, and F.R.S. against his charge of failure 
in Lagrange's method, he had passed them by in silence, and aimed 
at taking up ne ground. We submit, however, that the fair course of 
discussion absolutely requires that he should dispose of the objections, 
either by admitting their validity, or by refuting them, before he can 
have a claim further to occupy our pages on this subject. With his 
suggestion respecting the names of his opponents we cannot com- 
ply : nor are names of any consequence in such discussions. As to the 
letter of Veritas, it does not appear to contain any thing by which 
knowledge may be advanced, or our readers interested. — Ed. 



METEOROLOGICAL OBSERVATIONS FOR JUNE 1828. 

Gosport. — Numerical Results for the Month. 

Barom. Max. 30-33 June 26. Wind S.— Min. 29-35 June 1 8. Wind N.E. 
Range of the index 0-98. 

Mean barometrical pressure for the month 29-982 

Spaces described by the rising and falling of the mercury 4-610 

Greatest variation in 24 hours 0-550. — Number of changes 18. 
Therm. Max. 81° June 28. Wind S.E.— Min. 48° June 6. Wind N.W. 
Range 33°.— Mean temp.of exter. air 63°-63. For 30 days with in n 6210 
Max. var. in 24 hours 24°-00— Mean temp, of spring water at 8 A.M. 52°-44 

De Luc's Whalebone Hygrometer. 

Greatest humidity of the air in the evening of the 22nd 86° 

Greatest dryness of the air in the afternoon of the 8th 40 

Range of the index 46 

Mean at 2 P.M. 51°-2— Mean at 8 A.M. 57°7— Mean at 8 P.M. 63-7 

of three observations each day at 8, 2, and 8 o'clock 57*5 

Evaporation for the month 4-65 inches. 
Rain near ground 1-98 inches. 
Prevailing wind, S.W. 

Summary of the Weather. 
A clear sky, 5; fine, with various modifications of cloudy, 17; an over- 
cast sky without rain, 4 ; rain, 4, — Total 30 days. 

Clouds. 

Cirrus. Cirrocumulus. Cirrostratus. Stratus. Cumulus. Cumulostr. Nimbus 

25 16 29 29 23 14 

Scale of the prevailing Winds. 

N. N.E. E. S.E. S. S.W. W. N.W. Days. 

2 3 2£ 4 3 8 2* 5 30 

General Observations. — The first part of this month was alternately wet and 

dry, but from the 20th to the end, more favourable weather could not have 

happened for hay-making, which was performed generally in Hampshire 

with expedition, and the crops got in, in excellent condition. Early in the 

morning of the 5th a storm passed over to the eastward, with lightning and 

thunder: showers of rain and hail with distant thunder also occurred in 

the afternoon of the 6th. In the evening of the 7th a parhelion appeared 

in a cirrostratus cloud on the south side of the sun. From between two 

and 



Meteorological Observations for June 1828. 159 

and three till nearly six o'clock in the morning of the 15th, the weather 
was very awful here ; the lightning, which was chiefly forked, flashed vividly 
at short intervals ; its colour was dark-red ; it continued a long time in the 
zenith, and the explosions were so near, that the rushing of the adjacent 
air into the displacement to restore its equilibrium, shook the foundations 
of the houses. There were two winds at the same time ; viz. a strong gale 
next the earth from due North, surmounted by a slow moving current from 
S.E. as ascertained by the black thunder-clouds which the latter wind 
carried with it : by the inosculation of these winds, and clouds of unequal 
temperatures from nearly opposite points of the compass, the lightning was 
generated, and was awfully grand for upwards of two hours. No damage 
was done by the storm in this neighbourhood, but it was severely felt in 
the upper part of the country. The same morning between four and five 
o'clock, just before the heavy rain came on, a beautiful double rainbow ap- 
peared in a large nimbus to the westward ; the arc of the exterior bow ex- 
tended from about S.S.W. to W.N.W. The electric fluid which accom- 
panied the recent thunder-storms in this county was very powerful, having 
killed several men and horses. 

On the 20th, about 5 o'clock in the afternoon, an anthelion appeared 
in the eastern prime vertical, opposite to and 120 degrees distant from the 
sun. This rare phenomenon presented itself in a light brown cumulostratus 
cloud, from which it was distinguished by its circular silvery colour, which 
repeatedly contracted and expanded according to the effulgence of the sun. 
It continued in sight nearly two minutes, by which time the cloud had 
moved oft' too far to the north-east to exhibit the sun by reflection. 

The 28th and 29th were hot sunny days, the thermometer in the shade 
in the afternoons being at 80° and 81°, and in the sun's rays at 106°. 

The mean temperature of the external air this month is 2£ degrees higher 
than the mean of June for the last twelve years. 

The atmospheric and meteoric phenomena that have come within our 
observations this month, are one anthelion, one parhelion, four solar halos, 
two double rainbows, lightning and thunder on four different days ; and 
eight gales of wind, or days on which they have prevailed ; namely, one 
from the North, one from the North-east, one from the East, three from 
the South-west, and two from the West. 



REMARKS. 



London. — June 1 — 3. Very fine. 4. Rainy. 5. Cold and cloudy. 
6. Sultry: with thunder. 7. Clear and fair. 8. Fine: showery at night. 
9 — 1 1 . Very fine. 1 2. Sultry, and warm. 1 3 — 15. Very fine. 1 6. Drizzly. 
17. Sultry, and warm. 18. Showery in the morning: fine. 19. Cloudy, 
and warm. 20. Very fine. 21. Wet morning: fine. 22. Drizzly: fine. 
28 — 30. Very fine and warm. 

Boston. — June 1. Cloudy. 2 — 4. Fine : rain a.m. 5. Cloudy : rain a.m. 
hail-storm 1 p.m. rain at night. 6, 7. Cloudy. 8. Cloudy: rain a.m. 
9. Fine. 10— 13. Cloudy. 14. Fine. 15. Cloudy. 16. Fine. * 17. Cloudy: 
rain a.m. 18. Fine : rain a.m. and p.m. 19, 20. Fine. 21. Rain : thunder 
and lightning with rain p.m. 22. Fine: rain p.m. 23. Cloudy: rain p.m. 
24 — 27. Fine. 28—30. Cloudy. 

Penzance.—- June 1 . Fair : rain. 2. Clear. 3, 4. Rain : showers. 5. Clear : 
showers. 6. Fair : showers. 7. Fair. 8. Pair : clear. 9, 10. Clear. 11. Clear: 
fair. 12. Fair : at times clear. 13. Fair: clear. 14. Clear: cloudy: light- 
ning. 15. Misty. 16. Misty: showers. 17. Rain. 18. Rain: fair. 19. Fair: 
showers. 20. Fair. 21 /Clear: showers at night. 22. Clear. 23. Fair : 
clear. 24, 25. Clear. 26. Fair: clear. 27— 29. Clear. 30. Fair. 

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THE 

PHILOSOPHICAL MAGAZINE 

AND 

ANNALS OF PHILOSOPHY. 

[NEW SERIES.] 



SEP T EMBER 1828. 



XXVII. A brief Account of Microscopical Observations made 
in the Months of June, July, and August, 1827, on the Par- 
ticles contained in the Pollen of Plants ; and on the general 
Existence of active Molecules in Organic and Inorganic Bodies. 
By Robert Brown, F.R.S., Hon. M.R.S.E. $ R.I. Acad., 
V.P.L.S., Corresponding Member of the Royal Institutes of 
Prance and of the Netherlands, Sfc. fyc. 



[We have been favoured by the Author with permission to insert the fol- 
lowing paper, which has just been printed for private distribution. — Ed.] 

r | 1 HE observations, of which it is my object to give a sum- 
A mary in the following pages, have all been made with a 
simple microscope, and indeed with one and the same lens, 
the focal length of which is about ^nd of an inch*. 

The examination of the unimpregnated vegetable Ovulum, 
an account of which was published early in 1826f, led me to 
attend more minutely than I had before done to the structure 
of the Pollen, and to inquire into its mode of action on the 
Pistillum in Phaenogamous plants. 

In the Essay referred-to, it was shown that the apex of the 

* This double convex Lens, which has been several years in my pos- 
session, I obtained from Mr. Bancks, optician, in the Strand. After I 
had made considerable progress in the inquiry, I explained the nature of 
my subject to Mr. Dollond, who obligingly made for me a simple pocket 
microscope, having very delicate adjustment, and furnished with ex- 
cellent lenses, two of which are of much higher power than that above 
mentioned. To these I have often had recourse, and with great advantage, 
in investigating several minute points. But to give greater consistency to 
my statements, and to bring the subject as much as possible within the reach 
of general observation, I continued to employ throughout the whole of the 
inquiry the same lens with which it was commenced. 

T In the Botanical Appendix to Captain King's Voyages to Australia, 
vol. ii. p. 5.34. et seq. 

New Series. Vol. 4-. No. 2 1 . Sept. 1828. Y nucleus 



162 Mr. R. Brown on the Existence of active Molecules 

nucleus of the Ovulum, the point which is universally the seat 
of the future Embryo, was very generally brought into contact 
with the terminations of the probable channels of fecundation; 
these being either the surface of the placenta, the extremity of 
the descending processes of the style, or more rarely, a part 
of the surface of the umbilical cord. It also appeared, how- 
ever, from some of the facts noticed in the same Essay, that 
there were cases in which the Particles contained in the grains 
of pollen could hardly be conveyed to that point of the ovulum 
through the vessels or cellular tissue of the ovarium ; and the 
knowledge of these cases, as well as of the structure and 
economy of the antherae in Asclepiadece, had led me to doubt 
the correctness of observations made by Stiles and Gleichen 
upwards of sixty years ago, as well as of some very recent 
statements, respecting the mode of action of the pollen in the 
process of impregnation. 

It was not until late in the autumn of 1826 that I could at- 
tend to this subject ; and the season was too far advanced to 
enable me to pursue the investigation. Finding, however, in 
one of the few plants then examined, the figure of the particles 
contained in the grains of pollen clearly discernible, and that 
figure not spherical but oblong, I expected, with some confi- 
dence, to meet with plants in other respects more favourable 
to the inquiry, in which these particles, from peculiarity of 
form, might be traced through their whole course : and thus, 
perhaps, the question determined whether they in any case 
reach the apex of the ovulum, or whether their direct action 
is limited to other parts of the female organ. 

My inquiry on this point was commenced in June 1827, 
and the first plant examined proved in some respects remark- 
ably well adapted to the object in view. 

This plant was Clarckia pulchella, of which the grains of 
pollen, taken from antherse full grown, but before bursting, were 
filled with particles or granules of unusually large size, vary- 
ing from nearly ¥I ^ n th to about j^Wth of an inch in length, 
and of a figure between cylindrical and oblong, perhaps 
slightly flattened, and having rounded and equal extremities. 
While examining the form of these particles immersed in wa- 
ter, I observed many of them very evidently in motion ; their 
motion consisting not only of a change of place in the fluid, ma- 
nifested by alterations in their relative positions, but also not 
unfrequently of a change of form in the particle itself; a con- 
traction or curvature taking place repeatedly about the middle 
of one side, accompanied by a corresponding swelling or con- 
vexity on the opposite side of the particle. In a few in- 
stances the particle was seen to turn on its longer axis. These 
motions were such as to satisfy me, after frequently repeated ob- 
servation, 



in organic and inorganic Bodies. 163 

servation, that they arose neither from currents in the fluid, nor 
from its gradual evaporation, but belonged to the particle itself. 

Grains of pollen of the same plant taken from antherae im- 
mediately after bursting, contained similar subcylindrical par- 
ticles, in reduced numbers however, and mixed with other 
particles, at least as numerous, of much smaller size, ap- 
parently spherical, and in rapid oscillatory motion. 

These smaller particles, or Molecules as I shall term them, 
when first seen, I considered to be some of the cylindrical par- 
ticles swimming vertically in the fluid. But frequent and care- 
ful examination lessened my confidence in this supposition ; 
and on continuing to observe them until the water had entirely 
evaporated, both the cylindrical particles and spherical mole- 
cules were found on the stage of the microscope. 

In extending my observations to many other plants of the 
same natural family, namely Onagrarice, the same general 
form and similar motions of particles were ascertained to 
exist, especially in the various species of Oenothera, which I 
examined. I found also in their grains of pollen taken from 
the antherae immediately after bursting, a manifest reduction 
in the proportion of the cylindrical or oblong particles, and 
a corresponding increase in that of the molecules, in a less 
remarkable degree, however, than in Clarckia. 

This appearance, or rather the great increase in the number 
of the molecules, and the reduction in that of the cylindrical 
particles, before the grain of pollen could possibly have come 
in contact with the stigma, — were perplexing circumstances 
in this stage of the inquiry, and certainly not favourable to the 
supposition of the cylindrical particles acting directly on the 
ovulum; an opinion which I was inclined to adopt when I first 
saw them in motion. These circumstances, however, induced 
me to multiply my observations, and I accordingly examined 
numerous species of many of the more important and remark- 
able families of the two great primary divisions of Phaenoga- 
mous plants. 

In all these plants particles were found, which in the dif- 
ferent families or genera varied in form from oblong to sphe- 
rical, having manifest motions similar to those already de- 
scribed ; except that the change of form in the oval and ob- 
long particles was generally less obvious than in Onagrarice, 
and in the spherical particle was in no degree observable*. 

* In Lolium perenne, however, which I have more recently examined, 
though the particle was oval and of smaller size than in Onagrarice, this 
change of form was at least as remarkable, consisting in an equal contrac- 
tion in the middle of each side, so as to divide it into two nearly orbicular 
portions. 

Y2 In 



164 Mr. R. Brown on the Existence of active Molecules 

In a great proportion of these plants I also remarked the same 
reduction of the larger particles, and a corresponding increase 
of the molecules after the bursting of the antherae : the mole- 
cule, of apparently uniform size and form, being then always 
present ; and in some cases indeed, no other particles were 
observed, either in this or in any earlier stage of the secreting 
organ. 

In many plants belonging to several different families, but 
especially to Graminece^ the membrane of the grain of pollen 
is so transparent that the motion of the larger particles within 
the entire grain was distinctly visible ; and it was manifest also 
at the more transparent angles, and in some cases even in the 
body of the grain in Onagraricc. 

In Asclepiadete, strictly so called, the mass of pollen filling 
each cell of the anthera is in no stage separable into distinct 
grains ; but within, its tessellated or cellular membrane is filled 
with spherical particles, commonly of two sizes. Both these 
kinds of particles when immersed in water are generally seen in 
vivid motion ; but the apparent motions of the larger particle 
might in these cases perhaps be caused by the rapid oscillation 
of the more numerous molecules. The mass of pollen in this 
tribe of plants never bursts, but merely connects itself by a 
determinate point, which is not unfrequently semitransparent, 
to a process of nearly similar consistence, derived from the 
gland of the corresponding angle of the stigma. 

In Periplocece, and in a few Apocinece, the pollen, which in 
these plants is separable into compound grains filled with 
spherical moving particles, is applied to processes of the stigma, 
analogous to those of Asclepiadece. A similar economy exists 
in Orchidece, in which the pollen-masses are always, at least 
in the early stage, granular ; the grains, whether simple or 
compound, containing minute, nearly spherical particles, but 
the whole mass being, with very few exceptions, connected by 
a determinate point of its surface with the stigma, or a glan- 
dular process of that organ. 

Having found motion in the particles of the pollen of all the 
living plants which I had examined, I was led next to inquire 
whether this property continued after the death of the plant, 
and for what length of time it was retained. 

In plants, either dried or immersed in spirit for a few 
days only, the particles of pollen of both kinds were found 
in motion equally evident with that observed in the living 
plant; specimens of several plants, some of which had been 
dried and preserved in an herbarium for upwards of twenty 
years, and others not less than a century, still exhibited the 
molecules or smaller spherical particles in considerable num- 
bers, 



in organic and inorganic Bodies, . 165 

bers, and in evident motion, along with a few of the larger 
particles, whose motions were much less manifest, and in some 
cases not observable*. 

In this stage of the investigation having found, as I be- 
lieved, a peculiar character in the motions of the particles of 
pollen in water, it occurred to me to appeal to this peculiarity 
as a test in certain families of Cryptogamous plants, namely 
Mosses, and the genus Equisetum, in which the existence of 
sexual organs had not been universally admitted. 

In the supposed stamina of both these families, namely, in 
the cylindrical antherae or pollen of Mosses, and on the sur- 
face of the four spathulate bodies surrounding the naked 
ovulum, as it may be considered, of Equisetum, I found mi- 
nute spherical particles, apparently of the same size with the 
molecule described in Onagrarice, and having equally vivid 
motion on immersion in water ; and this motion was still ob- 
servable in specimens both of Mosses and of Equiseta, which 
had been dried upwards of one hundred years. 

The very unexpected fact of seeming vitality retained by 
these minute particles so long after the death of the plant, 
would not perhaps have materially lessened my confidence in 
the supposed peculiarity. But I at the same time observed, 
that on bruising the ovula or seeds of Equisetum, which at 
first happened accidentally, I so greatly increased the number 
of moving particles, that the source of the added quantity 
could not be doubted. I found also that on bruising first the 
floral leaves of Mosses, and then all other parts of those plants, 
that I readily obtained similar particles, not in equal quan- 
tity indeed, but equally in motion. My supposed test of the 
male organ was therefore necessarily abandoned. 

Reflecting on all the facts with which I had now become 
acquainted, I was disposed to believe that the minute spherical 
particles or Molecules of apparently uniform size, first seen in 
the advanced state of the pollen of Onagrarice, and most other 
Phaenogamous plants, — then in the antherae of Mosses and on 

* While this sheet was passing through the press I have examined the pol- 
len of several flowers which have been immersed in weak spirit about eleven 
months, particularly of Viola tricolor, Zizania aquatica, and Zea Mais; 
and in all these plants the peculiar particles of the pollen, which are oval 
or short oblong, though somewhat reduced in number, retain their form 
perfectly, and exhibit evident motion, though I think not so vivid as in 
those belonging to the living plant. In Viola tricolor, in which, as well as 
in other species of the same natural section of the genus, the pollen has a 
very remarkable form, the grain on immersion in nitric acid still dis- 
charged its contents by its four angles, though with less force than in the 
recent plant. 

the 



166 Mr. R. Brown on the Existence of active Molecules 

the surface of the bodies regarded as the stamina of Equi- 
setum,— and lastly in bruised portions of other parts of the 
same plants, were in reality the supposed constituent or ele- 
mentary molecules of organic bodies, first so considered by 
BufFon and Needham, then by Wrisberg with greater pre- 
cision, soon after and still more particularly by Muller, and, 
very recently by Dr. Milne Edwards, who has revived the 
doctrine and supported it with much interesting detail. I 
now therefore expected to find these molecules in all or- 
ganic bodies: and accordingly on examining the various 
animal and vegetable tissues, whether living or dead, they 
were always found to exist; and merely by bruising these 
substances in water, I never failed to disengage the molecules 
in sufficient numbers to ascertain their apparent identity in 
size, form, and motion, with the smaller particles of the 
grains of pollen. 

I examined also various products of organic bodies, parti- 
cularly the gum-resins, and substances of vegetable origin, 
extending my inquiry even to pit-coal ; and in all these bo- 
dies Molecules were found in abundance. I remark here also, 
partly as a caution to those who may hereafter engage in the 
same inquiry, that the dust or soot deposited on all bodies in 
such quantity, especially in London, is entirely composed of 
these molecules. 

One of the substances examined, was a specimen of fossil 
wood, found in Wiltshire oolite, in a state to burn with 
flame; and as I found these molecules abundantly, and in 
motion in this specimen, I supposed that their existence, 
though in smaller quantity, might be ascertained in mineralized 
vegetable remains. With this view a minute portion of silicified 
wood, which exhibited the structure of Coniferce, was bruised, 
and spherical particles, or molecules in all respects like those 
so frequently mentioned, were readily obtained from it; in 
such quantity, however, that the whole substance of the petri- 
faction seemed to be formed of them. But hence I inferred 
that these molecules were not limited to organic bodies, nor 
even to their products. 

To establish the correctness of the inference, and to ascer- 
tain to what extent the molecules existed in mineral bodies, 
became the next object of inquiry. The first substance ex- 
amined was a minute fragment of window-glass, from which, 
when merely bruised on the stage of the microscope, I readily 
and copiously obtained molecules agreeing in size, form, and 
motion with those which I had already seen. 

I then proceeded to examine, and with similar results, such 

minerals 



in organic and inorganic Bodies. 167 

minerals as I either had at hand or could readily obtain, 
including several of the simple earths and metals, with many 
of their combinations. 

Rocks of all ages, including those in which organic remains 
have never been found, yielded the molecules in abundance. 
Their existence was ascertained in each of the constituent 
minerals of granite, a fragment of the Sphinx being one of the 
specimens examined. 

To mention all the mineral substances in which I have 
found these molecules, would be tedious ; and I shall confine 
myself in this summary to an enumeration of a few of the 
most remarkable. These were both of aqueous and igneous 
origin, as travertine, stalactites, lava, obsidian, pumice, vol- 
canic ashes, and meteorites from various localities*. Of metals 
I may mention manganese, nickel, plumbago, bismuth, anti- 
mony, and arsenic. In a word, in every mineral which I 
could reduce to a powder, sufficiently fine to be temporarily 
suspended in water, I found these molecules more or less 
copiously ; and in some cases, more particularly in siliceous 
crystals, the whole body submitted to examination appeared 
to be composed of them. 

In many of the substances examined, especially those of 
a fibrous structure, as asbestus, actinolite, tremolite, zeolite, 
and even steatite, along with the spherical molecules, other 
corpuscules were found, like short fibres somewhat monili- 
form, whose transverse diameter appeared not to exceed that 
of the molecule, of which they seemed to be primary com- 
binations. These fibrils, when of such length as to be pro- 
bably composed of not more than four or five molecules, and 
still more evidently when formed of two or three only, were 
generally in motion, at least as vivid as that of the simple 
molecule itself; and which from the fibril often changing its 
position in the fluid, and from its occasional bending, might be 
said to be somewhat vermicular. 

In other bodies which did not exhibit these fibrils, oval 
particles of a size about equal to two molecules, and which 
were also conjectured to be primary combinations of these, 
were not unfrequently met with, and in motion generally more 
vivid than that of the simple molecule ; their motion consist- 
ing in turning usually on their longer axis, and then often 
appearing to be flattened. Such oval particles were found to 
be numerous and extremely active in white arsenic. 

As mineral bodies which had been fused contained the 

* I have since found the molecules in the sand-tubes, formed by light- 
ning, from Drig in Cumberland. 

moving 



168 Mr. R. Brown on the Existence of active Molecules 

moving molecules as abundantly as those of alluvial deposits, 
I was desirous of ascertaining whether the mobility of the 
particles existing in organic bodies was in any degree af- 
fected by the application of intense heat to the containing 
substance. With this view small portions of wood, both living 
and dead, linen, paper, cotton, wool, silk, hair, and muscular 
fibres, were exposed to the flame of a candle or burned in 
platina-forceps, heated by the blowpipe ; and in all these bo- 
dies so heated, quenched in water, and immediately submitted 
to examination, the molecules were found, and in as evident mo- 
tion as those obtained from the same substances before burning. 
In some of the vegetable bodies burned in this manner, in 
addition to the simple molecules, primary combinations of 
these were observed, consisting of fibrils having transverse 
contractions, corresponding in number, as I conjectured, with 
that of the molecules composing them ; and those fibrils, 
when not consisting of a greater number than four or five 
molecules, exhibited motion resembling in kind and vivacity 
that of the mineral fibrils already described, while longer 
fibrils of the same apparent diameter were at rest. . 

The substance found to yield these active fibrils in the 
largest proportion and in the most vivid motion, was the mu- 
cous coat interposed between the skin and muscles of the 
haddock, especially after coagulation by heat. 

The fine powder produced on the under surface of the 
fronds of several Ferns, particularly of Acrostichum calome- 
lanos, and the species nearly related to it, was found to be en- 
tirely composed of simple molecules and their primary fibre- 
like compounds, both of them being evidently in motion. 

There are three points of great importance which I was 
anxious to ascertain respecting these molecules, namely, their 
form, whether they are of uniform size, and their absolute 
magnitude. I am not, however, entirely satisfied with what I 
have been able to determine on any of these points. 

As to form, I have stated the molecule to be spherical, and 
this I have done with some confidence ; the apparent excep- 
tions which occurred admitting, as it seems to me, of being 
explained by supposing such particles to be compounds. This 
supposition in some of the cases is indeed hardly reconcileable 
with their apparent size, and requires for its support the further 
admission, that, in combination, the figure of the molecule may 
be altered. In the particles formerly considered as primary 
combinations of molecules, a certain change of form must also 
be allowed ; and even the simple molecule itself has sometimes 
appeared to me when in motion to have been slightly modified 
in this respect. 

My 



in organic and inorganic Bodies. 169 

My manner of estimating the absolute magnitude and uni- 
formity in size of the molecules, found in the various bodies 
submitted to examination, was by placing them on a micro- 
meter divided to five thousandths of an inch, the lines of which 
were very distinct; or more rarely on one divided to ten 
thousandths, with fainter lines, not readily visible without the 
application of plumbago, as employed by Dr. Wollaston, but 
which in my subject was inadmissible. 

The results so obtained can only be regarded as approxi- 
mations, on which perhaps, for an obvious reason, much re^ 
liance will not be placed. From the number and degree of 
accordance of my observations, however, I am upon the whole 
disposed to believe the simple molecule to be of uniform size, 
though as existing in various substances and examined in cir- 
cumstances more or less favourable, it is necessary to state 
that its diameter appeared to vary from Tj,£oo"th to 2o%o~oo tn 
of an inch # . 

I shall not at present enter into additional details, nor shall 
I hazard any conjectures whatever respecting these molecules, 
which appear to be of such general existence in inorganic as 
well as in organic bodies; and it is only further necessary 
to mention the principal substances from which I have not 
been able to obtain them. These are oil, resin, wax, and sul- 
phur; such of the metals as I could not reduce to that minute 
state of division necessary for their separation ; and finally, 
bodies soluble in water. 

In returning to the subject with which my investigation 
commenced, and which was indeed the only object I ori- 
ginally had in view, I had still to examine into the probable 
mode of action of the larger or peculiar particles of the pollen, 
which, though in many cases diminished in number before the 
grain could possibly have been applied to the stigma, and 
particularly in Clarckia, the plant first examined, were yet 
in many other plants found in less diminished proportion, 
and might in nearly all cases be supposed to exist in suffi- 
cient quantity to form the essential agents in the process of 
fecundation. 

I was now therefore to inquire, whether their action was 
confined to the external organ, or whether it were possible to 

* While this sheet was passing through the press, Mr. Dollond, at my re- 
quest, obligingly examined the supposed pollen of Equisetum virgatum with 
his compound achromatic microscope, having in its focus a glass divided into 
10,000ths of an inch, upon which the object was placed ; and although the 
greater number of particles or molecules seen were about -g-Bvcnnrth, yet the 
smallest did not exceed ^ ^ th of an inch. 

New Series. Vol. 4. No. 21. Sept. 182S. Z follow 



170 Mi*. R. Brown on the Existence of active Molecules 

follow them to the nucleus of the ovulum itself. My en- 
deavours, however, to trace them through the tissue of the 
style, in plants well suited for this investigation, both from the 
size and form of the particles, and the development of the fe- 
male parts, particularly Onagrarite, was not attended with 
success ; and neither in this nor in any other tribe examined, 
have I ever been able to find them in any part of the female 
organ, except the stigma. Even in those families in which 
I have supposed the ovulum to be naked, namely, Cycadece 
and Coniferce, I am inclined to think that the direct action of 
these particles, or of the pollen containing them, is exerted 
rather on the orifice of the proper membrane than on the apex 
of the included nucleus ; an opinion which is in part founded 
on the partial withering confined to one side of the orifice of 
that membrane in the larch, — an appearance which I have re- 
marked for several years. , 

To observers not aware of the existence of the elementary 
active molecules, so easily separated by pressure from all ve- 
getable tissues, and which are disengaged and become more 
or less manifest in the incipient decay of semitransparent parts, 
it would not be difficult to trace granules through the whole 
length of the style : and as these granules are not always vi- 
sible in the early and entire state of the organ, they would 
naturally be supposed to be derived from the pollen, in those 
cases at least in which its contained particles are not remark- 
ably different in size and form from the molecule. 

It is necessary also to observe, that in many, perhaps I 
might say in most plants, in addition to the molecules separable 
from the stigma and style before the application of the pollen, 
other granules of greater size are obtained by pressure, which 
in some cases closely resemble the particles of the pollen in 
the same plants, and in a few cases even exceed them in size : 
these particles may be considered as primary combinations of 
the molecules, analogous to those already noticed in mineral 
bodies and in various organic tissues. 

From the account formerly given of Asclepiadece, Peri- 
plocece, and Orckidete, and particularly from what was ob- 
served of Asclepiadea?, it is difficult to imagine, in this family 
at least, that there can be an actual transmission of particles 
from the mass of pollen, which does not burst, through the 
processes of the stigma; and even in these processes I have 
never been able to observe them, though they are in general 
sufficiently transparent to show the particles were they pre- 
sent. But if this be a correct statement of the structure of 
the sexual organs in Asclepiadetz, the question respecting this 
family would no longer be, whether the particles in the pollen 

were 



in organic and inorganic Bodies. 171 

were transmitted through the stigma and style to the ovula, 
but rather whether even actual contact of these particles with 
the surface of the stigma were necessary to impregnation. 

Finally, it may be remarked that those cases already ad- 
verted to, in which the apex of the nucleus of the ovulum, the 
supposed point of impregnation, is never brought into contact 
with the probable channels of fecundation, are more unfavour- 
able to the opinion of the transmission of the particles of the 
pollen to the ovulum, than to that which considers the direct 
action of these particles as confined to the external parts of 
the female organ. 

The observations, of which I have now given a brief ac- 
count, were made in the months of June, July and August, 
1827. Those relating merely to the form and motion of the 
peculiar particles of the pollen were stated, and several of the 
objects shown, during these months, to many of my friends, 
particularly to Messrs. Bauer and Bicheno, Dr. Bostock, Dr. 
Fitton, Mr. E. Forster, Dr. Henderson, Sir Everard Home, 
Captain Home, Dr. Horsfield, Mr. Kcenig, M. Lagasca, 
Mr. Lindley, Dr. Maton, Mr. Menzies, Dr. Prout, Mr. Re- 
nouard, Dr. Roget, Mr. Stokes, and Dr. Wollaston ; and the 
general existence of the active molecules in inorganic as well 
as organic bodies, their apparent indestructibility by heat, 
and several of the facts respecting the primary combinations 
of the molecules, were communicated to Dr. Wollaston and 
Mr. Stokes in the last week of August. 

None of these gentlemen are here appealed to for the cor- 
rectness of any of the statements made ; my sole object in 
citing them being to prove from the period and general extent 
of the communication, that my observations were made within 
the dates given in the title of the present summary. 

The facts ascertained respecting the motion of the particles 
of the pollen, were never considered by me as wholly original ; 
this motion having, as I knew, been obscurely seen by Need- 
ham, and distinctly by Gleichen, who not only observed the 
motion of the particles in water after the bursting of the pollen, 
but in several cases remarked their change of place within the 
entire grain. He has not, however, given any satisfactory 
account either of the forms or of the motions of these par- 
ticles, and in some cases appears to have confounded them with 
the elementary molecule, whose existence he was not aware of. 

Before I engaged in the inquiry in 1827, I was acquainted 
only with the abstract given by M. Adolphe Brongniart him-? 
self, of a very elaborate and valuable memoir, entitled " Re- 
cherches sur le Generation et le Developpement de VEmbryon 
dans les Vegetaux Phanerogames" which he had then read 

Z 2 before 



172 Mr. R. Brown on the Existence of active Molecules. 

before the Academy of Sciences of Paris, and has since pub- 
lished in the Annates des Sciences Naturelles. 

Neither in the abstract referred to, nor in the body of the 
memoir, which M. Brongniart has with great candour given 
in its original state, are there any observations, appearing of 
importance even to the author himself, on the motion or form 
of the particles ; and the attempt to trace these particles to 
the ovulum, with so imperfect a knowledge of their distinguish- 
ing characters, could hardly be expected to prove satisfactory. 
Late in the autumn of 1 827, however, M. Brongniart having 
at his command a microscope constructed by Amici, the cele- 
brated professor of Modena, he was enabled to ascertain many 
important facts on both these points, the result of which he 
has given in the notes annexed to his memoir. On the general 
accuracy of his observations on the motions, form, and size of 
the granules, as he terms the particles, I place great reliance. 
But in attempting to trace these particles through their 
whole course, he has overlooked two points of the greatest 
importance in the investigation. 

For, in the first place, he was evidently unacquainted with 
the fact, that the active spherical molecules generally exist in 
the grain of pollen along with its proper particles ; nor does it 
appear from any part of his memoir that he was aware of the 
existence of molecules having spontaneous or inherent mo- 
tion, and distinct from the peculiar particles of the pollen, 
though he has doubtless seen them, and in some cases, as it 
seems to me, described them as those particles. 

Secondly, he has been satisfied with the external appearance 
of the parts in coming to his conclusion, that no particles capa- 
ble of motion e'xist in the style or stigma before impregnation. 

That both simple molecules and larger particles of diffe- 
rent form, and equally capable of motion, do exist in these 
parts, before the application of the pollen to the stigma can 
possibly take place, in many of the plants submitted by him 
to examination, may easily be ascertained ; particularly in An- 
tirrhinum majus, of which he has given a figure in a more ad- 
vanced state, representing these molecules or particles, which 
he supposes to have been derived from the grains of pollen, 
adhering to the stigma. 

There are some other points respecting the grains of pollen 
and their contained particles in which I also differ from M. 
Brongniart, namely, in his supposition that the particles are 
not formed in the grain itself, but in the, cavity of the an- 
thera ; in his assertion respecting the presence of pores on 
the surface of the grain in its early state, through which the 
particles formed in the anthera, pass into its cavity ; and lastly, 

on 



M. Steinheil's New Micrometer. 173 

on the existence of a membrane forming the coat of his boyau 
or mass of cylindrical form ejected from the grain of pollen. 

I reserve, however, my observations on these and several 

other topics connected with the subject of the present inquiry 

for the more detailed account, which it is my intention to give. 

July 30, 1828. 

[The examination of the unimpregnated vegetable Ovulum, mentioned at 

the beginning of this Paper, will be found in Phil. Mag. vol. lxvii. p. 352.] 

XXVIII. On a New Micrometer, principally intended for the 
Construction of a more complete Map of the Heavens, By 
M. Steinheil. 

[With an Engraving.] 

To the Editors of the Philosophical Magazine and Annals. 
Gentlemen, 

I" HAVE lately received, through the kindness of Professor 
■*■ Schumacher, one of Fraunhofer's 42-inch refracting tele- 
scopes, with an object-glass of three inches diameter. This 
instrument is a most excellent one, and far exceeds any tele- 
scope of the same size that I have ever seen. Attached to it, 
there is one of M. Steinheil's new micrometers; the first, I be- 
lieve, that has ever reached this country. As a description of 
this invention may be interesting to many of your readers, 
I beg leave to send you the following translation (from No. 117 
of Professor Schumacher's Astronomische Nachrichte?i) 9 with 
which Dr. Tiarks has favoured me. 

I am, Gentlemen, your obedient servant, 

July 15, 1828. Francis Baily. 

The comparison of a celestial map with the heavens, for 
the purpose of inserting therein the stars of inferior mag- 
nitude, is subject to peculiar difficulties, as is well known to 
every one who has undertaken this task. The method de- 
scribed by Professor Bessel in No. 93 of the Astr. Nachr. is 
indeed exceedingly simple, and on that account much to be 
commended; but it is in one respect not quite satisfactory. 
For the differences of right ascension and declination with re- 
spect to the standard stars which determine the position of 
the stars to be inserted, can only be estimated by means of the 
cross wires; which is the more uncertain and unsatisfactory 
the greater those differences become. A method therefore by 
which these coordinates could be measured, appears to me to 
be a very desirable object : and would have the additional ad- 
vantage of doing away with the necessity of laying down the 
stars by candle-light, an operation at once tedious and hurtful 
to the eyes, as the observations may in the present case be re- 
duced 



174- M. Steinheil's New Micrometer, for the Construction 

duced at our leisure, and the stars afterwards inserted among 
the others in their proper places. 

Amongst the micrometers hitherto used, none answers this 
purpose; for those in which the field of view is illuminated, 
weaken the effect of the telescope too much ; and if illumi- 
.nated lines are employed, either these, or the faint stars when 
approaching near them, will disappear. This led me to the 
idea that the difficulty might be removed, if it were possible 
to illuminate at pleasure thin divided cross bars in the dark 
field of view. 

The beautiful discovery of Professor Gauss (Astr. Nachr. 
No. 43), that the diaphragm of a telescope may be seen by 
means of another, fixed in its axis, afforded me the means 
of effecting my object. With this view I fastened upon the ob- 
ject-glass of the telescope a second smaller object-glass, and 
then fixed in its focus a micrometer plate, so entirely perforated 
as to have nothing left but the above-mentioned cross bars. 
Parallel rays issuing both from the micrometer bars and a very 
distant object, situated in the optical axis of the telescope, will 
reach the large object-glass ; and the images of both these ob- 
jects will necessarily appear clearly over each other in the 
field of the telescope. 

In order to render the image of the micrometer visible on 
the dark ground of the heavens, the light, which I used for 
noting down my observations, was found sufficient without 
any other apparatus, and I was enabled to vary the brightness 
of the image, by changing the position of the light with respect 
to the optical axis of the telescope. On trying this method, 
however, it did not quite answer my expectation ; for it was still 
difficult to determine the position of very faint points of light, 
because they still disappeared in the vicinity of the bars, when 
illuminated ever so faintly. The very faint stars, therefore, 
which a telescope shows in the dark part of the field of view, 
will absolutely not bear any light in their vicinity. If their 
position with regard to other observed stars is to be ascertained, 
it is necessary to make them coincide with a dark object whose 
position with regard to the micrometer is known. For this 
purpose it will be sufficient (as Plate I. fig. A and A' show) to 
fasten in the eye-glass thick cross wires, or to give to the dia- 
phragm a square form instead of a round one ; by which means 
greater distances may be measured, even in case one could 
not distinguish either the cross wires, or the bounds of the 
field of view, from the dark appearance of the heavens. 

We may, however, determine the coincidence of the stars 
(as in a circular micrometer) from their disappearance. If the 
star that is to be observed has been thus noted, the telescope 

is 



of a more complete Map of the Heavens. 175 

is moved until a brighter observed star passes the illuminated 
micrometer ; and the difference is then read off. It is clear 
that this method is to be applied to very small stars only, as 
it requires more time than the direct observation on the illu- 
minated bars. 

Although we have thus described the essential parts of the 
construction and use of this micrometer, we hope that those 
who are engaged in revising the maps of the heavens will still 
be pleased to see a detailed description of its adaptation to a 
Fraunhofer's sweeper ; that being the instrument intended by 
Professor Bessel for the revision of the maps. In determining 
the construction of such an instrument, we must take care, 

1°. That the small object-glass should intercept as little of 
the light coming to the larger object-glass as possible ; and yet 
should present a sufficiently clear image of the micrometer 
plane. I have found by trial, that the limits of the measure 
of brightness of the same should be W, 3 and 0'"'8 Paris lines : 
2°. That the micrometer plane should be entirely covered 
by the small object-glass in regard to the object-glass of the 
eye-piece : 

3°. That the micrometer plane should extend over the 
whole field of view. 

Besides these conditions, there are restrictions arising from 
the mechanical execution of the small micrometer plane, the 
intensity of the light for its illumination, &c. &c. ; so that 
after the limits, between which the dimensions must be se- 
lected, have been found by calculation, practice only will lead 
to the most advantageous combination. In this manner I 
found, if the dimensions of the telescope are as follow, — viz. 

Focal length of the object-glass 288 Paris lines. 

Aperture 34? do. 

Diameter of the object- {Collective-) glass of > ~ _, 

the eye-piece \ °* 

Field of view 4° 

Magnifying power 15 times, — 

that the following construction of the micrometer is the most 
advantageous: viz. 

Focal length of the micrometer object-glass 74'" 

Aperture 9 

Diameter of the object-glass with frames 11*4 

External or greatest diameter of the micrometer plane 6' 5 

Interior or smallest 5*0 

One division of the micrometer plane 0*1 

Fig. 1. represents the micrometer as adapted and fitted to 
the telescope. 

The micrometer plane (a) consists of a small plate of silver 

(a piece 



176 M. Steinheil's New Micrometer, for the Construction 

(a piece of very smooth ivory would be preferable), on which 
a rectangular net-work has been cut by means of a dividing 
engine, and which is then filed out so that nothing remains 
but the small bars represented in the figure. These bars, of 
the breadth of a division of the micrometer, must contract in 
breadth towards the back part, in order to appear clearly de- 
fined in every position of the eye. The divisions are cut 
pretty deep, in order to be easily seen by a small portion of 
light. The reading off is facilitated by a dot placed at every 
fifth division. 

This plane, as well as the arm that supports it, must be 
blackened (without polish), in order to prevent all reflection of 
light. The arm (b) which carries the micrometer is a drawn 
tube of brass, as it must be stiff and light. It is held in a 
socket (c), which is screwed to the ring (d). The small ob- 
ject-glass, which has its flint lens turned towards the micro- 
meter plane, is fastened by its support (e) to the socket (c). 
The support (e) must be blackened, and should be broad 
enough to prevent any reflection of light (a') from coming 
into the field of view. 

In making the adjustments, which must precede the use of 
the instrument, some advantages have presented themselves 
to me, which I shall here describe, in order to save others the 
trouble of finding them out. 

First, the eye-piece is to be so placed, that the perfect di- 
stinctness of the image be not in the centre of the field, but at 
an equal distance from the border and the centre. For this 
position the parallax of the cross wires in the eye-glass is first 
to be destroyed, and they are to be placed parallel to the 
motion of the axis of the telescope. 

The micrometer must next be fastened to the telescope, and 
the micrometer plane must be placed parallel to the small ob- 
ject-glass (for which operation a distant object may be used), 
and the arm (b) must be slid backward and forward, until the 
parallax between the cross wires of the eye-piece and the bars 
of the micrometer plane is destroyed. 

In order to adjust approximately the position of the cross 
wires, with regard to the micrometer plane, as is shown in 
fig. A, it should be observed, that the image of the cross wires 
may be distinctly seen in the same plane with the micrometer 
plane if the eye is placed in the optical axis behind the micro- 
meter. Keeping this image in view, we may turn the arm (b) to- 
gether with the connecting ring (d) about their axes, and change 
the position of (a 1 ) until the cross wires are respectively parallel 
to and bisect the micrometer bars. The errors which may 
then still remain may be easily corrected by repeating the same 

operation 



of a . more complete Map of the Heavens. 177 

operation while looking into the telescope. The degree of 
force used in clamping the screws will cause a slight alteration 
in the position of the two images, which may be subsequently 
remedied in a similar manner. 

That the telescope should have an equatorial motion, and be 
provided with an apparatus for minute changes of the axis, is 
clear from the preceding description. 

I shall now add some observations as originally noted down, 
together with their comparison with meridian observations, 
in order to give some idea of the degree of accuracy which may 
be attained by single readings off. 



Position in 1800. Star compared. 



Name. 



8 Orionis 



5 h 2l m 4?Sj6 



-0° 27',5 



Above — ; Below + ; Right + ; Left — ; 1 Division = 2'-866. 



Observation 1827- 


Reduction 


to 1800. 


AS 


Direc- 
tion. 


Ax. 


Correc- 
tion. 


Direc- 
tion. 


Magni- 
tude. 


V 


Merid. 
Obser. 


V 


Merid. 
Obser. 


6,3 


B 


12,9 





R 


8 


-0° 9',5 


0',0 


5 h 24 m 15 s ,5 


- 0",2 


4,0 


B 


1,6 


6",4 


R 


8,9 


-0 16,0 


0,0 


24 44 ,6 


-1,5 


1,0 


B 


16,45 




R 


8,9 


-0 24,6 


-0,2 


24 56 ,1 


-0,0 


18,5 


A 


22,4 


— 


R 


2 


-1 20,6 


+ 0,2 


26 4 ,3 


—0,5 


17,8 


A 


8,3 


— 


R 


7 


-1 18,5 


-0,1 


23 22 ,8 


-0,2 


15,2 


A 


11,0 


— 


R 


7 


-1 11,2 


+ 0,1 


23 53 ,7 


+0,9 


16,65 


A 


11,5 


— 


L 


H,7 


— 1 15,4 


-0,3 


19 35 ,8 


+ 0,2 


10,6 


A 


11,9 


— 


L 


7 


-0 57,9 


-0,3 


19 31 ,1 


—0,3 


7,8 


A 


— 


3 


R 


9 


-0 35,3 


+ 0,2 


21 50 ,6 


+ 0,9 


1,5 


A 


3,3 


— 


L 


9 


-0 13,8 


+0,2 


23 37 ,4 


+ 0,6 



The telescope used is one by Fraunhofer, of 34 w aperture, 
42" focal length, and magnifying 23 times : observations with 
a sweeper would be somewhat more uncertain # . 

As the scale which has been adopted in the maps, does not' 
well admit of greater accuracy than 0',5 in the position of the 
stars, no sensible error can arise from this method of observing^ 
even with a sweeper. By the former methods, errors amountr 



* [I do not understand the notation here introduced; but I presume 
it means 34 Paris lines (= 3 English inches), and 42 Paris inches^ = 45 
English inches) : at least, these are the dimensions of my telescope, — F. B.] 



New Series. Vol. 4. No.21. Sept 1828. 2 A 



ing 



178 M. Steinheil's New Micrometer. 

ing to two or three minutes are unavoidable, even with the 
greatest attention. 

Addition. — It may be desirable to mention, that the micro- 
meter-apparatus here described may be made use of also as 
an achromatic microscope, if the object to be viewed is brought 
into the focus of the small object-glass instead of the micro- 
meter-plane. But it will be necessary, for the purpose of illu- 
minating it and of rendering it more commodious, to give to 
the whole a more convenient construction. The small object- 
glass might (as shown in fig. 2.) be screwed into a tube which 
could be clamped to the telescope, and should in such case 
have two incisions in the focus of the small object-glass, in 
order to receive the frame holding the object which is to be 
viewed. Although this object may not be perfectly in the 
focus, its image may be rendered distinct by changing the po- 
sition of the eye-glass in the telescope. The ring, represented in 
the figure, will serve to support the telescope and microscope. 

The power of this microscope is, independently of its abso- 
lute size, the more considerable, the greater the ratio of the 
aperture of the second object-glass to its focal length. It 
would, therefore, be more advantageous to use object-glasses 
composed of more than two lenses. Perfect object-glasses of 
four lenses would, as far as spherical aberration is concerned, 
admit of almost a double aperture, and, as the loss of light by 
refraction and reflection is very small, their effect would be 
nearly double. The image would likewise gain in distinctness, 
as it would be possible to destroy the chromatic aberration for 
rays incident at a distance from the axis. 

I am now engaged in calculating such object-glasses, and 
M. Merz (the director of the establishment of Utzschneider 
and Fraunhofer) having promised the execution of them, I hope 
to be able at some future period to communicate the result of 
my labours. 

If we are satisfied with a double lens, the effect of this 
microscope is somewhat less than that of Fraunhofer's ; be- 
cause, in the latter the object may be brought nearer to the 
object-glass than its focal distance. The advantage which it 
may, however, claim over it, is the absolutely greater focal di- 
stance of the object-glass of the microscope, in consequence 
of which the whole of an object of some thickness may be 
viewed with distinctness at the same time. It seems to deserve 
the attention of travellers, on account of the ease with which 
every one can thus convert his telescope into a microscope. 
Different eye-glasses would, of course, change the field of 
view and the magnifying power of such a microscope. 

I must 



Mr. Galbraith on Sound, and the Ellipticity of the Earth. 179 

I must apologize for having mentioned a subject which is 
not astronomical, on account of its intimate connexion with 
the preceding part of this paper. 

Steinheil. 



XXIX. Comparison of a Formula representing the Velocity of 
Sound, with Capt. Parry and Lieut. Foster's Experiments 
on that Subject at Port Bowen ; with some Remarks on the 
Ellipticity of the Earth. By Wm. Galbraith, Esq. A.M. 

To the Editors of the Philosophical Magazine and Annals. 
Gentlemen, 
TN the first volume of the New Series of the Phil. Mag., 
•*- p. 337, I have given two formulae to determine the velocity 
of sound. It would be more convenient, however, to adapt 
that for the temperature by Fahrenheit's thermometer to zero 
of that scale, and it becomes 

V=(102-4225 + 0*11030(l+ gr^:27)(10-2739- 0-0138 cos 2X] 

+ co cos <p. 
This gives the velocity in English feet, when the English ba- 
rometer and Fahrenheit's thermometer are used. 

By a comparison of this formula adapted to the centigrade 
thermometer, I found an almost perfect accordance with Dr. 
Moll's experiments. I also found that the effect of wind on 
the 27th of June 1823 was about 19 feet, — half the difference 
between the velocities, as determined from each extremity of 
the base. Indeed there can be little doubt that the velocity 
of sound is affected by that of the wind at the time. Dr. Gre- 
gory of Woolwich, in a series of experiments on sound de- 
tailed in the first volume of the Transactions of the Cambridge 
Philosophical Society*, expressly states that the wind increases 
or diminishes the velocity of sound according as it blows in 
the same or in an opposite direction ; — a conclusion which 
might almost a priori have been anticipated. The only diffi- 
culty is, to adapt the formula to the actual state of the atmo- 
sphere with regard to moisture. The expansion of the dry air 
with which Messrs. Dulong and Petit operated, was 0*375 from 
the freezing point to the boiling point of water. It is a little 
greater, however, in moist air, such as exists in an ordinary 
state of the atmosphere. Laplace in that case assumed 0*4<, and 
from a mean of a great number of experiments on air, sound, 
&c. I found 0*4112, that adopted in the above formula. 

* See Phil. Mag. vol. Ixiii. p. 401.— Edit. 

2 A 2 Now 



180 



Mr. Galbraith on the Velocity of Sound, 



Now this is very nearly true in the usual state of the atmo- 
sphere, but in extreme cases of dryness and moisture it must 
vary a little from this, so that I have not been able to discover 
the exact quantity of variation. From such comparisons as 
I have been able to make, it seems, however, in its present 
state, to be pretty accurate. As I have already, in the volume 
referred to, shown its agreement with Professor Moll's ex- 
periments, I shall now compare it with those made by Captains 
Parry and Foster at Port Bowen ; and as they had no anemo- 
meter to determine the velocity of the wind, I shall make a 
probable estimation of its effects, from Smeaton's table in the 
51st volume of the Philosophical Transactions, as nearly as 
I can, from the account of the weather given along with the 
observations, and the angle between the direction of the wind 
and sound estimated to the nearest point, that being the de- 
gree of accuracy attainable only from the data, page 86, Ap- 
pendix to the Third Voyage. 

Experiments made at Port Bowen, in Latitude 73° 14' N. 
The extent of the measured Base was 12892*89 feet, and the 
bearings of the Gun S. 71° 48' E. 



1824. 



Bar 
in 

Inches 



Temp. 



Wind. 



Weather. 



Interval in Seconds be- 
tween Flash and Report. 



Exp. 
Velocity 
per sec. 



Nov.24 
Dec. 8 
1825. 
Jan. 10 
Feb. 7 
17 
21 

Mar. 2 

22 
June 3 
4 



29-841 
29-561 

30-268 
29-647 
29-598 
29*735 

30-398 

30-258 
30-118 
30-102 



- 7 C 

- 9 

-37 
-24-5 
-18 
-37-5 

-38-5 

-21-5 
+33 -5 
+35 



E.S.E. 
N.N.E. 

K.S.E. 
N.E. 

calm 
calm 

easterly 

wester 1 y 
easterly 



light 
squally 

light 
light 



light 

light 

light 
strong, 
squally 



overcast 
very clear 

clear 

very clear 

overcast 

overcast 

f a little 1 

\ overcast J 

f very clear I 

\ and fine J 

very clear 

> clear 



P. 

12 s - 3525 
12 -3310 

12 -5889 
12 -6390 
12 -3720 
12 -8167 

12 -6400 

12 .4000 
11 -7333 
11 -5889 



F. 

12* -4300 
12 -5266 

12 -4700 
12 -6167 
12 -4400 
12 -7067 

12 -7800 

12 -7167 
11 -7440 
11 -4733 



Mean, 
12 s -3912 
12 -4288 

12 -5290 
12 -6278 
12 -4060 
12 -7617 

12 -71C0 

12 -5583 
11 -7387 
11 -5311 



1040-49 
1037-34 

1029-04 
1020-99 
1039-25 
1010-28 

1014-39 

1026-64 
1098-32 
1118-10 



Now, by applying the above formula, in which t is the tem- 
perature by Fahrenheit's thermometer, f the elastic force of 
aqueous vapour, p the barometric pressure, A the latitude, 
w the velocity of the wind, and <p the angle between the wind 
and sound. Above 0° Fahr. I have taken f according to the 
temperature marked, which cannot cause any great error. 



1824. 



and on the Ellipticity of the Earth. 



181 



1824. 



Exp. 
Velocity 
in feet. 



Contained 
Annie. 



Nov. 24 
Dec. 8 

1825. 

Jan. 10 

Feb. 7 

17 

21 

Mar. 2 

22 

June 3 

4 



1040-49 
1037-34 

1029-04 
1020-99 
1039-25 
1010-28 
1014*39 
1026*64 
1098-32 
1118-10 



4° 18' 
85 42 



Calculated 
Velocity. 



Estimated 

Effect of 

Wind. 



63 


12 


18 


12 


161 


48 


18 


12 


16 


48 



1045-51 
1043-24 

1011-48 
1025-66 
1033-03 
1010-91 
1009-78 
1029-06 
1092-82 
1094-60 



Final 
Velocity. 



+ 
+ 

+ 
+ 



4-0 
4-0 

4«0 
2-0 



+ 4-0 
— 4*0 
+ 4-0 
+ 25-0 



1049-5 
1047*2 

1015-5 

1027-7 
1033-0 
1010-9 
1013-8 
1025-1 
1096-8 
1119-6 



Differ- 
ence. 



9-0 
9-9 



-13-5 

+ 6-7 

- 5-7 
+ 0-6 

- 0-6 

- 1-5 

- 1-5 
+ 1-5 



Mean error of the whole 
Of a single set .... ... 



4-9 
0-5 



In most of the above experiments, the experimental and 
calculated velocities approximate very closely. There is, no 
doubt, some uncertainty in the estimated effect of the wind, 
though it is believed it cannot be great. Perhaps it is a little 
too great in the first two experiments. I cannot reconcile the 
third very well by any probable supposition. The only one 
on which the effect of the wind is considerable, is the last, when 
it was strong and squally, and blowing nearly in the direction 
of the sound. Upon the whole, the comparison appears satis- 
factory, though it would have been less objectionable had the 
velocity of the wind been ascertained by experiment, and its 
direction more accurately observed. 

I may add, that since my last communication on experi- 
ments by the pendulum, I have reconsidered the whole; and 
upon rejecting those evidently affected with some cause not well 
explained, I have found the following formula : 

P == 39-01326+0*20686 sin 3 (X— 0) (A) 

In which P is the length of the pendulum, A the observed 
latitude, and the reduction of the latitude. 
Also g = 0-00330 = ~±j very nearly ; 
And P at London by computation from formula (A) is 
39-13937, while I have found it from Captain Kater's experi- 
ments to be 39-13938, almost exactly the same. P at Paris, 
by the same formula is 39-12982, or 0*00053 greater than by 
experiment. And these two instances show the great accuracy 
of the formula. 

The 



182 On the Reduction of Circummeridian Altitudes of the Sun. 

The most probable ellipticity by the pendulum-experiments 

appears to be, from my calculations, 0*00330 

The same, from my comparison of degrees . . . 0*00322 

Mr. Ivory's investigations give from arcs 0*00324 

Laplace adopted 0*00326 

Mean of the whole 0*00327 

It is probable that Mr. Ivory's ellipticity, or 0*00324, is the 
most accurate of the whole, and may safely be adopted as that 
to which it will ultimately converge, since it satisfies all the 
most accurate arcs hitherto measured with extreme precision. 

But the most extraordinary circumstance attending all these 
comparisons is their discrepancy from those of Mr. Professor 
Airy, of Cambridge, who finds from Captain Sabine's pen- 
dulum-experiments 0*003474 ; and still more so the result of 
his comparison of arcs, which is 0*003589 ! these arcs being 
the very same as those which Mr. Ivory and I have employed. 
To what cause then must this discordance be attributed ? Can 
it be supposed that the Professor has committed an error 
either in his investigations, or in his calculations, or in both ? 
In such an important investigation it would be most desirable 
to see the whole scrutinized with great care, and this scrutiny 
would come with a better grace from the Professor himself than 
from any other individual. I am, Gentlemen, yours, &c. 

Edinburgh, June 18, 1828. WlLLlAM GALBRAITH. 



XXX. On the Reduction of Circummeridian Altitudes of the 

Sun*. 

PROFESSOR GAUSS's ingenious method of effecting the 
usual reduction of circummeridian altitudes of the sun not 
having yet been noticed in any English work, the following 
deduction of the same will perhaps deserve a place in the 
Philosophical Magazine. Let 

<p= the latitude of the place of observation. 
8= the sun's declination at noon. 
J8 = the change of the sun's declination in 24 hours at noon 
expressed in seconds. 
— t = the number of seconds any observation was taken 

before noon. 
+ t =z the number of seconds any observation was taken 
after noon. 
0= the observed altitude of the sun for the time /. 
M = the meridian altitude of the sun. 

* Communicated by the Author. 

We 



Prof. Hare's improved Eudiometrical Apparatus. 183 

We shall then have for every observation the following equa- 
tion : 

O + at 2 -bt = M 

t_ 15*. »in 1" cos <p . cos 2 7 

where a = . . \ ^ : b = 



sin (<p-$) ' 86400 

Let — =t seconds; and we shall have + a(t— t) 9 = 

M+tfT 2 , where the part on the right is the same for every 
observation, t being independent of t. This equation shows 
that the greatest, O, will belong to t—r = 0, or t = t, and will 

exceed the meridian-altitude M by ar 2 [ = -£-\ or that r 

seconds after noon the sun will attain his highest altitude 
M + tfT 2 , to which every observed altitude may be reduced by 
the addition of the single term a [t—r) 2 ; t—r will evidently 
be the number of seconds elapsing between the observation 
and the moment of the sun's highest altitude. This moment 

is found by this equation: r (= - — ) = A , '* m \ , 

J n \ 2a/ 100 . cos <p . cos $ \ 

log. N = 0*0257289, and r is positive in the ascending, and 
negative in the descending signs. Prof. Schumacher publishes 
annually a table of the values of t for every tenth day of the 
year, and every degree of latitude from 36° to 60°. It is un- 
necessary to add, that the quantities a (£— t) 2 for every obser- 
vation, and the constant quantity ar 2 , are calculated by the 
assistance of the well-known tables of Delambre, Dr. Young, 
and others. 

We entirely avoid, therefore, by this method, the calcula- 
tion of the term bt, or the change of declination for every ob- 
servation. M. Von Heiligenstein, who has explained this me- 
thod in Prof. Schumacher's Astr. Nachrichten, No. 134, has 
neglected the quantity «t 2 , which indeed never amounts to 
0"*25 ; but it is clear that this is not correct, and that where 
great accuracy is required it certainly ought to be taken into 
consideration. J. L. T. 

XXXI. Improved Eudiometrical Apparatus. By R. Hare, 
M.D. Professor of Chemistry in the University of Pennsyl- 
vania. 

[Concluded from page 134.] 

Of the Barometer-Gauge Eudiometer by Phosphorus. 

A HOLLOW glass spheroid A, of which the vertical dia- 
■*-*• meter is 11 inches, the horizonal diameter 9 inches, is 
cemented into a brass socket which screws into the Same place 

as 



184« Prof. Hare's improved Eudiometrical Apparatus. 

as the socket of the receiver of the eudiometer above de- 
scribed. In lieu 
of the igniting 
wires employed 
in that instru- 
ment, a cup 
containing phos- 
phorus is sup- 
ported by and 
closes the upper 
end of a tube T. 
This tube is sol- 
dered] into the 
axis of a brass 
plug, screwed in 
at the bottom of 
the brass cast- 
ing, which at 
top receives the 
socket of the 
spheroid. The 
phosphorus be- 
ing ignited by 
means of a hot 
iron passed up 
through the tube, 

the oxygen of the air included in the spheroid is condensed, 
and the deficit ascertained by the gauge. 

It will be recollected that the gauge of the barometer-gauge 
eudiometer is graduated into 450 degrees. It is expedient to 
commence this experiment with the mercury at 50 degrees, 
which leaves 400 parts in the spheroid, and allows room for 
the expansion which takes place in the beginning of the pro- 
cess. 

I have made several experiments with this apparatus, and 
find the results to harmonize with each other, and with those 
obtained by my other instruments. 

Upon the wire W, which passes through the stuffing box 
into the cavity of the spheroid, a copper hood is supported, 
which is just large enough to cover the cap containing the 
phosphorus. By this contrivance the phosphorus may be 
secluded from the air, until its exposure becomes desirable. 

On one side of the spheroid a thermometer maybe observed, 
which is so fastened by means of a stuffing-box, as that the 
bulb is within, while the stem is without, and may be easily 
inspected. A small sliding band enables the operator to mark 

the 




Prof. Hare's improved Eudiometrical Apparatus. 185 

the place to which the thermometrical liquid reaches before 
the ignition of the phosphorus, and of course enables him, by 
awaiting its return to the same position, to know when the heat 
arising from the combustion has escaped so as to permit the 
bulk of the residual air to be fairly measured. 

• 

Of the Carbonicometer Or Gasilotor ; 

An Apparatus for withdrawing a known Portion of residual 
Gas from the Receiver of the Barometer-Gauge Eudiometer, 
in order to cause the Absorption of Carbonic Acid by Agitation 
with Lime-water. 

A mixture of oxygen with carbonic oxide, or carburetted 
hydrogen, may be exploded in the barometer-gauge eudiome- 
ter. Any ensuing deficit will be seen bv the effect upon the 
gauge. 

The quantity of carbonic acid 
produced, may be ascertained by 
means of the instrument described 
in the following article. 

p is a pipe which causes a com- 
munication between the upper part 
of the receiver R, and the cavity 
under the hollow pedestal B. The 
lower orifice of this pipe, where it 
enters the cavity of the pedestal, 
is covered by a valve opening 
downwards. The receiver is sur- 
mounted by a brass cap, into which, 
as well as into the socket in the 
pedestal, it is cemented air-tight. 
In the axis of the receiver, and 
descending nearly to the bottom, 
may be seen a tube, which is sol- 
dered into a perforation communi- 
cating with the bore of the cock 
C, so as to establish a communi- 
cation between the receiver and 
the globe G. 

The globe is surmounted by a 
valve-cock V, furnished with a 
gallows and screw, so that a leaden 
pipe D, terminated by a brass knob 
duly perforated, may be joined to 
it, air-tight, without difficulty. Hence if the pipe be annexed 
at the other end to the cock of the barometer-gauge eudio- 

New Series. Vol.4. No. 21. Sept. 1828. 2B meter, 




186 Prof. Hare's improved Eudiometrkal Apparatus. 

meter, a communication between the inside of the receiver of 
this instrument and the globe G, may be easily opened or 
suspended at pleasure. 

The screw S serves to open or close a perforation which 
communicates with the cavity of the receiver. 

Suppose the receiver R to be occupied by lime-water as 
represented in the figure. Place the pedestal B over the 
hole in the air-pump plate, which the rim of the pedestal is 
ground to fit. On working the pump, the air of the receiver 
above the lime-water is drawn out through the valve at the 
bottom of the pipe p. Of course the air in the globe follows 
it through the pipe, which leads from it into the receiver. 
Having exhausted the globe and receiver, if the screw S be 
so loosened as to allow the atmosphere to enter the receiver, 
and press upon the surface of the lime-water while the globe 
remains exhausted, the lime-water will of course rise into and 
fill the globe. Should the receiver under these circumstances 
be again exhausted, while by means of the flexible pipe D a 
communication with the barometer-gauge eudiometer is ef- 
fected, the pressure of the gas in the eudiometer being greater 
than that of the rare medium of the exhausted receiver R, — it 
follows that this gas will press into the globe and cause a por- 
tion of the lime-water to descend into the receiver. In this 
way, suppose 100 measures, by the barometer-gauge, taken 
from the eudiometer. The valve-cock may then be closed, 
and the screw S relaxed so as to admit the atmosphere. The 
lime-water will rise into the globe until the pressure of the 
gas therein be nearly equal to that of the atmosphere. By 
agitating the globe, the carbonic acid will combine with the 
lime in the water. When this object is effected, the residual gas 
may be allowed to re-enter the eudiometer, where the quan- 
tity of it may be measured, and consequently the extent of 
the absorption known. It is not necessary that the apparatus 
should remain upon the air-pump plate during the whole pro- 
cess. By means of the valve which covers the perforation in 
the pedestal, in which the pipe P is inserted, the exhaustion 
may be sustained during the removal of the receiver from the 
air-pump to any part of the laboratory where it may be con- 
venient to connect it with the eudiometer. 

I have designated this instrument as a carbonicometer in 
my text-book, to avoid circumlocution. It may however be 
more properly called a washer of gas, than a measurer of car- 
bonic acid. Hence the term gasilotor would be more appro- 
priate. The employment of new names may appear pedantic 
to some readers, but is really necessary, in order to avoid te- 
dious, and, at times, almost unintelligible circumlocution. 

XXXII. Of 



[ 187 ] 

XXXII. Of the Litrameter. By R. Hare, M.D. Professor 
of Chemistry in the University of Pennsylvania*. 

LITRAMETER is a name derived from « meter," and the 
Greek Xngot (weight), and is given to one of the instru- 
ments which I have 
contrived for ascertain- 
ing specific gravities. 
The litrameter owes its 
efficiency to the princi- 
ple, that when columns 
of different liquids are 
elevated by the same 
pressure, their heights 
must be inversely as 
their gravities. 

Two glass tubes, of 
the size and bore usu- 
ally employed in baro- 
meters, are made to 
communicate internally 
with each other, and 
with a syringe R, by 
means of a brass tube 
and two sockets of the 
same metal, into which 
they are severally in- 
serted. The brass tube 
terminates in a cock, to 
which the syringe is 
screwed. 

The tubes are placed 
vertically, in grooves, 
against an upright strip 
of wood, tenoned into 
a pedestal of the same 
material. Parallel to 
one of the grooves, in 
which the tubes are si- 
tuated, a strip of brass 
SS is fastened; and 
graduated so that each 
degree may be about 
equal to 1*110 of the 
whole height of the 
tubes. The brass plate 

* Communicated by the Author. 

2 B2 is 




188 Prof. Hare's Litramcter. 

is long enough to admit of about 70 degrees. Close to this 
scale, a vernier v is made to slide, so that the divisions of the 
scale are susceptible of subdivision into tenths, and the whole 
height of the tubes into about 1100 parts, or degrees. 

On the left of the tube, there is another strip of brass, with 
another set of numbers so situated as to divide each of the 
degrees in the scale above mentioned into two : so that, agree- 
ably to this enumeration, the height of the tubes is, with the 
aid of a corresponding vernier, divided into 2200 parts or de- 
grees. 

A small strip of sheet-tin k is let into a notch in the wood, 
supporting the tubes, in order to indicate the commencement 
of the scale. At distances from this of 1000 parts, and 2000 
parts (commensurate with those of the scale), there are two 
other indices TT to the right-hand tube. Let a small vessel 
containing water be made to receive the lower end of the tube 
by the side of which the scale is situated, and a similar vessel 
of any other fluid, whose gravity is sought, be made to receive 
the lower end of the other tube ; so that the end of the one 
tube may be covered by the liquid in question, and the end 
of the other tube by the water. 

The piston of the syringe being previously pushed into the 
chamber as far as possible, is now to be moved in the opposite 
direction. By these means the air is rarefied in the chamber 
and in the glass tubes, and consequently it allows the liquids 
to rise into the tubes, in obedience to the greater pressure of 
the atmosphere without. If the liquid to be assayed be heavier 
than water ; as, for instance, let it be concentrated sulphuric 
acid, it should be raised a little above the first index, at the 
distance of 1000 degrees from the common level of the orifices 
of the tubes. The vessels holding the liquids being then 
lowered, so that the result may be uninfluenced by any in- 
equality in the height of the liquids in them, the column of 
acid must be lowered until its upper surface coincide exactly 
with the index of one thousand. Opposite the upper surface 
of the column of water, the two first numbers of the specific 
gravity of the acid will then be found ; and by duly adjusting 
and inspecting the vernier, the third figure will be ascertained. 
The liquids should be at the temperature of 60°. 

If the liquid under examination be lighter than water, as in 
the case of nearly pure alcohol, it must be raised to the upper 
index. The column of water measured by the scale of 1000, 
will then be found at 800 nearly ; which shows that one thou- 
sand measures of alcohol are, in weight, equivalent to 800 
measures of water — or, in other words, 800 is ascertained to 
be the specific gravity of the alcohol. 

The 



Mr. Ivory on Measurements of perpendicular Degrees, 189 

The plummet P, and the screws at L, enable the operator 
to detect and rectify any deviation from perpendicularity in 
the instrument. 



XXXIII. On Measurements on the Earth's Surface perpendi- 
cular to the Meridian. By J. Ivory, Esq. M.A. F.R.S.* 

A FTER so many laborious researches undertaken to deter- 
-^ mine the figure of the earth, the opinions of philosophers 
upon that point are still very unsettled. In proof of this it 
will be sufficient to cite what is advanced in the latest memoir 
on this subject, in which it is said that the compression 7 £ n is 
adopted, because it is the mean between 7 | n and ^g, the li- 
mits between which the ellipticity is generally supposed to be 
comprised f. There is at least great prudence in this pro- 
cedure; for at the same time that the particular ellipticity is 
pitched upon which is nearly the best fitted to reconcile all 
the phaenomena with the measurements of the Survey, there is 
no risk incurred that the truth, when it can no longer be dis- 
puted, will fall beyond the boundaries mentioned. In the 
Numbers of this Journal for May and June last, the elliptical 
elements of the earth are deduced from the five most esteemed 
measurements of meridional arcs in our possession ; and it is 
fully proved that the elements found represent the five di- 
stances on the meridian with great accuracy. As far as our 
present knowledge extends, we are therefore entitled to infer 
that the terrestrial meridians are equal ellipses of a known ex- 
centricity, and the earth itself an elliptical spheroid having a 
known compression at the poles. 

Till additional surveys shall enable us to establish the fore- 
going conclusion, or to correct it, if it be erroneous, we may 
inquire what light will be thrown on the question by measure- 
ments perpendicular to the meridian. In this Journal for 
July last, I have shown that, in the English Survey, the ope- 
rations at Beachy Head and Dunnose, for finding the length 
of a degree perpendicular to the meridian, lead to a result that 
accords exactly with the same spheroid deduced from the me- 
ridional arcs. My present intention is to examine some more 
instances of the same kind ; and I shall begin with putting the 
formula I used for computing the difference of longitude into 
a form more convenient for calculation. 

* Communicated by the Author. f Phil. Trans. 1828, p. 132. 

Referring 



190 Mr. Ivory on Measurements on the Earth's Surface 

Referring to this Journal, July last, pp. 8 and 9, for the ex- 
planation of the symbols employed, I shall now put 

Sin4 = £ 

2 2a 

Si„i-= i-*/ (i >-K)« + (?-0°: 
and it is obvious that sin — • is no other than half the chord 

i 

of the elliptical meridian comprehended between the latitudes 
of the two stations, which may be computed to any required 
degree of exactness. If now we substitute these values in the 
equation at the top of p. 9, we shall get, 



Sin 3 —- -sin 9 — -pusin 2 — ; 



and hence, 



2 cos X cos X \ 2 2 / 

r, in logarithms, 

/ sin — ~ sin ^~- \ 
Log sin -„- = \ log V * f_ J 

o 2 * . o V cos X cos X' J 



cos X cos X' Jr 2 

(sin 2 X + sin 2 A') (A) 

This formula, when i = 0, coincides with the usual rule for 
finding an angle of a' spherical triangle when the three sides 
are given, £ being the base, and I the difference of the sides. 
If we observe that small arcs of the elliptical meridian and of 
the equator, which are equal in length, have very nearly equal 
chords, we shall readily obtain this formula for finding % which 
is very convenient in practice, viz. 

8 = (x-V) . \ 1 - 1 (-i + 4 cos (*> *')) } ( a ) 

I shall now add another formula for finding the difference 
of longitude when there is given, the azimuth at one station, 
and the latitude of the other, together with the length of the 
chord between them. Let m denote the azimuth at the first 
station, that is, the angle between the meridian and the second 
station ; A f , the latitude of the second station ; and y, the length 
of the chord : further put R for the radius of a sphere the 
surface of which passes through the two stations, and touches 
the horizon of the first : then the difference of longitude co, 

will 



perpendicular to the Meridian. 191 

will be found by this formula, which is exact and easily de- 
monstrated by the most simple geometry, viz. 

a cos 7J 4 Ra 

Now it is obvious that R will always be very nearly equal to 
a ; and since y is always a small part of R, or of a 9 we may 

take ~r as equivalent to ■—. But if we make sin-£- = — . 

4a 2 * 4R* 2 2a > 

then cos ~ = V 1 — 5 and — V 1— -£r = 2 sin -^- 

2 4« a a 4a'* 2 

cos — = sin /3 : and thus we obtain, 

cv sin /3 sin m ,- : — - — 7 

Smw= -. — Vl— 2esin 2 A', 

COSX' 7 

or, in logarithms, 

Logsin» = log(^^)-M s sin'V. (B) 

In illustration of these rules I am tempted to apply them 
for finding the difference of longitude between the observa- 
tories at Greenwich and Paris. In the new survey the length 
of the arc drawn from Dover perpendicular to the meridian 
of Greenwich, is 50634? fathoms*. I consider the foot of this 
arc as the first station in the formula (B), and Dover as the 
second station. Hence, m — 90°; X' = 50° 7' 45"-6. As the 
given distance is not a chord, but an arc on the earth's surface, 
we shall find /3 by reducing the given length, taken as an arc 

of the earth's equator, to degrees : therefore $ = 6 x 3600" 

= 49' 53"*3. The formula (B) will now give us the longi- 
tude of Dover equal to 

1° 19'23"'78. 

As we have no azimuth either at Dover or Dunkirk, we must 
apply the formula (A). The two latitudes are, 

Dover A = 51° 7' 45"-6 

Dunkirk A' = 51 2 8-5. 

General Roy makes the distance from Dover to Dunkirk equal 
to 244916 feet f, or 40822 imperial fathoms. According to 
the mode of calculation in the Survey, this length is not a chord, 

but an arc on the earth's surface ; and hence /3 ss ^-r x 3600" 

=40' 14"-87. The formula (a) gives 8 = 5' 36"-91. We have 
therefore, by the formula (A), the difference of longitude be- 
tween Dover and Dunkirk equal to 
1° 3' 19"-10. 

* Phil. Trans. 1828, p. 180. f Trig. Survey, vol. i. p. 147. 

The 



1 92 Mr. Ivory on Measurements on the Earth 1 s Surface 

The sum of the two results is the longitude of Dunkirk, 
2° 22' 42"*88 : and as the meridian of Paris is 2' 22" west of 
the meridian of Dunkirk *, we get the difference of longitude 
of the two observations, equal to, 

In degrees. In time. 

2° 20' 20"*88 9 m 2P-39 

By experiment, P. T. 1826, 9 21-46 

Defect... 0-07 
In order to confirm the result obtained at Beachy Head, 
I shall add a similar instance taken from the New Survey. At 
the station of Fairlightf, the angle between the meridian 
and Blancnez, was found 85° 36' 36"*73 = m ; the latitude of 
Blancnez is 50° 55' 29"*36 = A'. The arc on the earth's sur- 
face between the two stations is 42117*6 fathoms; and hence 

= f£»& x 36 °0 7 = 41'.3l"-51. The formula (B) will now 
give us the difference of longitude of the two stations equal to 
1° 5' 33"*42. According to the Survey, the length of the per- 
pendicular arc at Blancnez is 41998*66 fathoms; and the 
amplitude of this arc, computed from the difference of longi- 
tude, is 41' 19"*58; and hence, by proportion, the perpendi- 
cular degree is 60976 fathoms. Now, at the latitude of Blanc- 
nez, a perpendicular degree on the surface of the spheroid is 
60974*5 fathoms. 

It appears lhat the perpendicular degrees at Beachy Head 
and at Blancnez on the French coast, agree very exactly with 
the elliptical spheroid deduced from the meridional arcs. The 
coincidence of the curvature of the earth's surface with the 
same spheroid in this region, may likewise be inferred from the 
calculation of the difference of longitude between Greenwich 
and Paris, which brings out a result so near the quantity ob- 
tained by direct observation. Let us next inquire how the case 
will stand at a very distant part of the globe. Colonel Lamb- 
ton has made in India a measurement precisely similar to that 
at Beachy Head and Dunnose in the British Survey. The 
particulars of this measurement at the two stations are as fol- 
lows :f : Curnatighur. Carangooly. 
Azimuth, 92° 49' 15"*93 = w, Azimuth, 87° 0' 7"*54 
Latitude, 12 34 38 -85, Latitude, 12 32 12 -27 = A' 

Feet. Fathoms. 

Rectilineal distance 291189*3=48531*5 

Perpendicular arc at Carangooly, 290841 = 48473*5 

* Conn, dcs Terns. t Phil. Trans, p. 186. 

% Asiatic Researches, vol. viii. 

As 



perpendicular to the Meridian. 1 93 

As in this instance we have the rectilineal distance of the 
stations, or the chord y between them, we must find by the 

formula sin -f- =s -£- = ~—\ whence /3 = 47' 50"*94. With 

2 la 2;> A ■ 

this value of ]3, and the values of m and *' noted above, the 
difference of longitude will be found, by the formula (B), equal 
to 48' 57"*05. From this we get 47' 47"*03, for the amplitude 
of the perpendicular arc at Carangooly, and 60866 fathoms, 
for the perpendicular degree, very little different from 60865*2, 
the length on the surface of the spheroid at the latitude of 
Carangooly. 

But if the measurements made in England and India are 
all represented by the same spheroid, Why should not the 
case be the same in France ? We have a great tendency to 
infer uniformity in the works of Nature, which principle is in 
reality the foundation of every physical inquiry. And if the 
public were put in possession of the extensive operations that 
have been executed in France and the north of Italy, for de- 
termining an arc of the mean parallel, there can be little doubt 
that we should be able to prove that all the degrees of the pa- 
rallel are equal, and agree in their length with the dimensions 
of the spheroid we have been considering. But at present we 
cannot draw our arguments from so rich a source, and we 
shall be content with examining a single instance taken from 
the great meridional measurement of France. 

The length of an arc drawn perpendicular to the meridian 
of Dunkirk from La Rogiere, in latitude 44° 34' 36"*6 is, ac- 
cording to the survey, 27534*6 toises *. This length is a de- 
duction from actual measurement, and is independent of any 
hypothesis about the figure of the earth. The arc is 29345*2 
fathoms ; and, by proceeding as in the example of Dover, we 
get = 28' 55"*95, and the difference of longitude =40' 33"*21. 
In order to find the amplitude of the arc, we must know the 
latitude of the point where it cuts the meridian. Now, ac- 
cording to the survey, the small arc of the meridian, between 
the foot of the perpendicular and the parallel of La Rogiere, 
is = 114*3 toises = 121*7 fathoms, making 7"*2 of difference 
of latitude. The latitude of the foot of the perpendicular is 
therefore, 44° 34' 43"*8; whence we get the amplitude = 
28' 53"* 18, and the length of the perpendicular degree = 
60953 fathoms, exactly the same as on the surface of the 
spheroid at the latitude 44° 34' 43"*8. 

In this last instance, as well as in all the others, the degree 
perpendicular to the meridian measured on the earth's surface, 

* Sate Metrique t vol. iii. p. 268. 

New Series. Vol.4. No. 21. Sept. 1828. 2 C is 



194 Mr. De la Beche on M. Oltmanns' Tables for 

is very consistent with the dimensions of the spheroid deduced 
from the meridional arcs. Now La Rogiere is only 1° 9' south 
of the parallel on which the measurements have been made in 
France and Italy ; and it is well known that the result of 
these operations requires a compression considerably different 
from what we have investigated. Here there is a difficulty 
of some moment, which it would be interesting to discuss, but 
which the length of this article precludes us from entering 
upon at present. 
August 8, 1828. J. Ivory. 



XXXIV. The Tables of Oltmanns for calculating Heights by 
the Barometer > rendered applicable to English Barometers and 
Measures. By H. T. De la Beche, Esq. F.R.S.* 

r T , HE French Board of Longitude have given these Tables 
■*■ in their Annuaire for the last two or three years, and 
state that they appear to them " the most convenient of all 
those hitherto published, for facilitating the calculation of 
heights." After this eulogium it would be useless for me to 
add any thing in favour of their merits, the chief of which 
consists in their great simplicity. 

Being calculated for the metrical barometer, these tables 
were useless to persons employing that graduated according 
to English inches and their decimal parts. To render them 
applicable to our barometers, I have prefixed a table (A), in 
which the equivalent of every millimetre of the metrical baro- 
meter is given in English inches and the hundredth parts of 
inches, which is sufficiently close for all practical purposes. 

To reduce the metres used in these tables into English feet, 
I have appended a table (F), where the number of English 
feet corresponding to any number of metres up to 10,000 will 
be immediately obtained. 

Abstraction being made of table A prefixed, and table F 
appended, the march of operations is as follows : 

Let h be the height of the barometer at the lower station 
expressed in millimetres ; h! that of the higher station ; T and 
T' the temperature of the barometer at the different stations 
according to the centigrade thermometer, t and t' that of the 
air. 

We search in table B for the number which corresponds 
to h ; let us call it a : we likewise search in the same table for 
that which corresponds to /*'; let this be named b: let us call 

* Communicated by Mr. De la Beche. 

c, the 



calculating Heights by the Barometer, 195 

c, the generally very small number which, in table C, faces 
T— T'; the approximate height will be a—b—c. (If T— T' 
is negative, it should be written a—b + c.) In order to apply 
the correction necessary for the strata of air, it will suffice to 
multiply the thousandth part of the approximate height by the 
double sum 2 (t + t 1 ) of the detached thermometers ; the cor- 
rection will be either positive or negative, according as t + t? is 
itself either positive or negative. 

The second and last correction, that for the latitude and 
the diminution of weight, is obtained by taking, in table D, 
the number which corresponds vertically to the latitude, and 
horizontally to the approximate height : this correction, which 
can never exceed 28 metres, is always added. 

In those very rare cases where the lower station is itself con- 
siderably elevated above the sea, it will be necessary to apply 
a small correction to be found in table E. 

In order to understand the calculation of a height by means 
of these tables, and those prefixed and appended, let us sup- 
pose that in latitude =44° we had at the level of the sea, the 
barometer = 30*04 English inches, temperature of the instru- 
ment = 22°*5 centigrade, and of the air =22°. At the top of 
a mountain, the barometer =26*57 English inches, tempera- 
ture of the instrument =17*5, and of the air =17°. 

In order to obtain the equivalents of the English inches in 
millimetres, search in table A ; where the number of millime- 
tres corresponding to 30*04 inches observed at the sea will 
be 763, and that of 26*57 observed on the mountain will be 
675. Having obtained these equivalents, the calculation pro^ 
ceeds : Mill. Metres. 

Barometer at sea level = 763 = 6182*01 rp , i r> 

Barometer on the mountain = 675 = 5206*1 / 

975*9 
DifF. of attached thermometers = 5° = 7*4 Table C. 

Apparent height 968*5 

Double the sum of the detached ^ 

thermometers multiplied by the > ... 75*5 

thousandth part of 968*5 j 

1044* 

Correction for latitude 3*1 Table D. 

Height of the mountain 1047*1 

Height in English feet 3435 Table F. 



2C2 



196 



M. Oltmanns' Tables for 
Table A. 



Inches. 


Milli. 


Inches. 


Milli. 


Inches. 


Milli. 


14-56 


370 


16-22 


412 


17*87 


454 


14*60 


371 


16-26 


413 


17-91 


455 


14-64 


372 


16-29 


414 


17-95 


456 


14-68 


373 


16-33 


415 


17*99 


457 


14-72 


374 


16-37 


416 


18-03 


458 


14-76 


375 


16-41 


417 


18-07 


459 


14-80 


376 


16*45 


418 


18-11 


460 


14-84 


377 


16-49 


419 


18-15 


461 


14-88 


378 


16-53 


420 


18-19 


462 


14-92 


379 


16*57 


421 


18-22 


463 


14-96 


380 


16-61 


422 


18-26 


464 


15-00 


381 


16-65 


423 


18*30 


465 


15-04 


382 


16-69 


424 


18-34 


466 


15-07 


383 


16-73 


425 


18-38 


467 • 


15-11 


384 


16-77 


426 


18-42 


468 


15-15 


385 


16-81 


427 


18-46 


469 


15-19 


386 


16-85 


428 


18-50 


470 


15-23 


387 


16-89 


429 


18-54 


471 


15-27 


388 


16-93 


430 


18-58 


472 


15-31 


389 


16*97 


431 


18-62 


473 


15-35 


390 


17*00 


432 


18-66 


474 


15-39 


391 


17-04 


433 


18-70 


475 


15-43 


392 


17*08 


434 


18-74 


476 


15-47 


393 


17*12 


435 


18-77 


477 


1^-51 


394 


17-16 


436 


18-81 


478 


15-55 


395 


17*20 


437 


18-85 


479 


15-59 


396 


17*24 


438 


18-89 


480 


15-63 


397 


17*28 


439 


18-93 


481 


15-67 


398 


17*32 


440 


18-97 


482 


15-71 


399 


17-36 


441 


19-01 


483 


15-75 


400 


17*40 


442 


19-05 


484 


15-78 


401 


17*44 


443 


19-09 


485 


15-82 


402 


17-48 


444 


19-13 


486 


15-86 


403 


17-52 


445 


19-17 


487 


15-90 


404 


17*55 


446 


19-21 


488 


15-94 


405 


17*59 


447 


19*25 


489 


15-98 


406 


17*63 


448 


19-29 


490 


16-02 


407 


17*67 


449 


19-33 


491 


16*06 


408 


17-71 


450 


19-37 


492 


16-10 


409 


17-75 


451 


19-41 


493 


16*14 


410 


17-79 


452 


19-44 


494 


16-18 


411 


17-83 


453 


19-48 


495 



calculating Heights by the Barometer. 
Tabl£ A. {continued.) 



197 



Inches. 


Milli. 


Inches. 


Milli. 


Inches. 


Milli. 


19*52 


496 


21*18 


538 


22-83 


580 


19-56 


497 


21-22 


539 


22-87 


581 


19-60 


498 


21-26 


540 


22-91 


582 


19*64 


499 


21-30 


541 


22-95 


583 


19-68 


500 


21-33 


542 


22-99 


584 


19*72 


501 


21-37 


543 


23-03 


585 


19*76 


502 


21*41 


544 


23-07 


586 


19-80 


503 


21*45 


545 


23-11 


587 


19-84 


504 


21-49 


546 


23*15 


588 


19*88 


505 


21-53 


547 


23*19 


589 


19-92 


506 


21-57 


548 


23*23 


590 


19-96 


507 


21*61 


549 


23*26 


591 


20*00 


508 


21*65 


550 


23*30 


592 


20*04 


509 


21*69 


551 


23*34 


593 


20*08 


510 


21*73 


552 


23-38 


594 


20-11 


511 


21*77 


553 


23-42 


595 


20*15 


512 


21-81 


554 


23-46 


596 


20*19 


513 


21-85 


555 


23-50 


597 


20-23 


514 


21-88 


556 


23-54 


598 


20-27 


515 


21-92 


551 


23*58 


599 


20-31 


516 


21*96 


558 


23-62 


600 


20-35 


517 


22-00 


559 


23-66 


601 


20-39 


518 


22-04 


560 


23*70 


602 


20*43 


519 


22-08 


561 


23-74 


603 


20*47 


520 


22*12 


562 


23*78 


604 


20-51 


521 


22*16 


563 


23-82 


605 


20-55 


522 


22-20 


564 


23-85 


606 


20*59 


523 


22*24 


565 


23-89 


607 


20-63 


524 


22*28 


566 


23-93 


608 


20-66 


525 


22*32 


567 


23*97 


609 


20*70 


526 


22*36 


568 


24*01 


610 


20*74 


527 


22-40 


569 


24-05 


611 


20-78 


528 


22*44 


570 


24*09 


612 


20-82 


529 


22*48 


571 


24*13 


613 


20*86 


530 


22-52 


572 


24-17 


614 


20*90 


531 


22*55 


573 


24*21 


615 


20*94 


532 


22-59 


574 


24*25 


616 


20*98 


533 


22*63 


575 


24*29 


617 


20-02 


534 


22-67 


576 


24-33 


618 


21-06 


535 


22-71 


577 


24*37 


619 


21-10 


536 


22-75 


578 


24*41 


620 


21-14 


537 


22-79 


579 


24*45 


621 



198 



M. Oltmanns' Tables for 
Table A. {continued.) 



Inches. 


Milli. 


Inches. 


Milli. 


Inches. 


Milli. 


24-48 


622 


26-14 


664 


27-79 


706 


24-52 


623 


26-18 


665 


27*83 


707 


24-56 


624 


26-22 


666 


27*87 


708 


24-60 


625 


26-25 


667 


27-91 


709 


24-64 


626 


26-29 


668 


27*95 


710 


24-68 


627 


26-33 


669 


27-99 


711 


24-72 


628 


26-37 


670 


28-03 


712 


24-76 


629 


26-41 


671 


28-07 


713 


24-80 


630 


26-45 


672 


28-11 


714 


24-84 


631 


26-49 


673 


28-14 


715 


24-88 


632 


26-53 


674 


28-18 


716 


24-92 


633 


26-57 


675 


28-22 


717 


24-96 


634 


26-61 


676 


28-26 


718 


25-00 


635 


26-65 


677 


28-30 


719 


25-03 


636 


26-69 


678 


28-34 


720 


25-07 


637 


26-73 


679 


28-38 


721 


25-11 


638 


26-77 


680 


28-42 


722 


25-15 


639 


26*81 


681 


28-46 


723 


25-19 


640 


26-85 


682 


28-50 


724 


25-23 


641 


26-88 


683 


28-54 


725 


25-27 


642 


26-92 


684 


28-58 


726 


25-31 


643 


26-96 


685 


28-62 


727 


25-35 


644 


27-00 


686 


28-66 


728 


25-39 


645 


27-04 


687 


28-70 


729 


25-43 


646 


27-08 


688 


28-74 


730 


25-47 


647 


27-12 


689 


28-78 


731 


25-51 


648 


27-16 


690 


28-82 


732 


25-55 


649 


27-20 


691 


28-85 


733 


25-59 


650 


27-24 


692 


28-89 


734 


25-63 


651 


27-28 


693 


28-93 


735 


25-67 


652 


27-32 


694 


28-97 


736 


25-70 


653 


27-36 


695 


29-01 


737 


25-74 


654 


27-40 


696 


29-05 


738 


25-78 


655 


27-44 


697 


29-09 


739 


25-82 


656 


27-48 


698 


29-13 


740 


25-86 


657 


27-52 


699 


29-17 


741 


25-90 


658 


27-56 


700 


29-21 


742 


25-94 


659 


27-60 


701 


29-25 


743 


25-98 


660 


27-63 


702 


29-29 


744 


26-02 


661 


27-67 


703 


29-33 


745 


26-06 


662 


27-71 


704 


* 29-36 


746 


26-10 


663 


27-75 


705 


29-40 


747 



calculating Heights by the Barometer. 
Table A. {continued.) 



199 



Inches. 


Milli. 


Inches. 


Milli. 


Inches. 


Milli. 


29*44? 


748 


30-00 


762 


30-55 


776 


29-48 


749 


30-04 


763 


30-59 


777 


29-52 


750 


30-07 


764 


30-63 


778 


29-56 


751 


30-11 


765 


30-66 


779 


29*60 


752 


30-15 


766 


30*70 


780 


29-64 


753 


30-19 


767 


30-74 


781 


29-68 


754 


30-23 


768 


30-78 


782 


29-72 


755 


30-27 


769 


30-82 


783 


29-76 


756 


30-31 


770 


30-86 


784 


29-80 


757 


30-35 


771 


30-90 


785 


29*84 


758 


30-39 


772 


30-94 


786 


29-88 


759 


30-43 


773 • 


30-98 


787 


29-92 


760 


30-47 


774 


31-02 


788 


29-96 


761 


30-51 


775 


31*06 


789 






Tabi 


.E B. 







Milli. 


Metres. 


Milli. 


Metres. 


Milli. 


370 


418-5 


394 


919*0 


418 


371 


440-0 


395 


939*2 


419 


372 


461-5 


396 


959-3 


420 


373 


482-9 


397 


979-4 


421 


374 


504-2 


398 


999*5 


422 


375 


525-4 


399 


1019-5 


423 


376 


546-6 


400 


1039*4 


424 


377 


567-8 


401 


1059-3 


425 


378 


588-9 


402 


1079-1 


426 


379 


609-9 


403 


1098-9 


427 


380 


630-9 


404 


1118-6 


428 


381 


651-8 


405 


1138-3 


429 


382 


672-7 


406 


1157*9 


430 


383 


693-5 


407 


1177*5 


431 


384 


714-3 


408 


1197-1 


432 


385 


735-0 


409 


1216-6 


433 


386 


755-6 


410 


1236-0 


434 


387 


776-2 


411 


1255-4 


435 


388 


796-8 


412 


1274-8 


436 


389 


817*3 


413 


1294-1 


437 


390 


837-8 


414 


1313-3 


438 


391 


858-2 


415 


1332-5 


439 


392 


878-5 


416 


1351-7 


440 


393 


898-8 


417 


1370-8 


441 



Metres. 
1389-9 
1408-9 
1427-9 
1446-8 
1465-7 
1484-6 
1503-4 
1522-2 
1540-8 
1559-5 
1578-2 
1596-8 
1615-3 
1633-8 
1652-2 
1670-6 
1689-0 
1707-3 
1725-6 
1743-8 
1762-1 
1780-3 
1798-4 
1816-5 



200 



M. 01tmanns , Tables for 
Table B. {continued,) 



Milli. 


Metres. 


Milli. 


Metres. 


Milli. 


Metres. 


442 


1834*5 


484 


2557*3 


526 


3220-0 


443 


1852-5 


485 


2573-7 


527 


3235-1 


444 


1870*4 


486 


2590-2 


528 


3250-2 


445 


1888-3 


487 


2506-6 


529 


3265-3 


446 


1906-2 


488 


2622-9 


530 


3280-3 


447 


1924-0 


489 


2639*2 


531 


3295-3 


448 


1941-8 


490 


2655-4 


532 


3310-3 


449 


1959-6 


491 


2671-6 


533 


3325-3 


450 


1977*3 


492 


2687*9 


534 


3340-2 


451 


1994-9 


493 


2704-1 


535 


3355-1 


452 


2012-6 


494 


2720-2 


536 


3370-0 


453 


2030*2 


495 


2736-3 


| 537 


3384-8 


454 


2047*8 


496 


2752-3 


538 


3399-6 


455 


2065*3 


497 


2768*3 


539 


3414-4 


456 


2082-8 


498 


2784-4 


540 


3429*2 


457 


2100-2 


499 


2800-4 


541 


3443-9 


458 


2117*6 


500 


2816-3 


542 


3458-6 


4.59 


2135-0 


501 


2832-2 


543 


3473-3 


460 


2152*3 


502 


2848-1 


544 


3487*9 


461 


2169*6 


503 


2864-0 


545 


3502-5 


462 


2186*9 


504 


2879-8 


546 


3517*2 


463 


2204-1 


505 


2895-6 


547 


3531-8 


464 


2221-3 


506 


2911-3 


548 


354>6S 


465 


2238-4 


507 


2927*0 


549 


3560-8 


466 


2255-5 


508 


2942-7 


550 


3575'3 


467 


2272-6 


509 


2958-4 


551 


3589-8 


468 


2280-6 


510 


2974-0 


552 


3604-2 


469 


23066 


511 


2989-6 


553 


3618-6 


470 


2323-6 


5J2 


3005-2 


554 


3633-0 


471 


2340-5 


513 


3020-7 


555 


3647-4 


472 


2357-4 


514 


3036-2 


556 


3661-7 


473 


2374-2 


515 


3051-7 


557 


3676-0 


474 


2391-1 


516 


3067*2 


558 


3690-3 


475 


2407-9 


517 


3082-6 


559 


3704-6 


476 


2424-6 


518 


3097-9 


560 


3718-8 


477 


2441-3 


519 


3113-3 


561 


3733-0 


478 


2458-0 


520 


3128-6 


562 


3747*2 


479 


2474-6 


521 


3143*9 


563 


3761*3 


480 


2491-3 


• 522 


3159-2 


564 


3775-4 


481 


2507*9 


523 


3174-4 


565 


3789-5 


482 


2524-3 


524 


3189*7 


566 


3803-6 


483 


2540-8 


525 


3204-9 


561 


3817*7 



calculating Heights by the Barometer, 
Table B. {continued.) 



201 



Milli. 


Metres. 


Milli. 


568 


3831-7 


611 


569 


3845*7 


612 


570 


3859-7 


613 


571 


3873-7 


614 


572 


3887-6 


615 


573 


3901-5 


616 


574. 


3915-4 


617 


575 


3929*3 


618 


576 


3943-1 


619 


577 


3956-9 


620 


578 


3970-7 


621 


579 


3984-5 


622 


580 


3998-2 


623 


581 


4011-9 


624 


582 


4025-6 


625 


583 


4039-3 


626 


584 


4052-9 


627 


585 


4066-6 


628 


586 


4080-2 


629 


587 


4093-8 


630 


588 


4107*3 


631 


589 


4120-8 


632 


590 


4134-3 


633 


591 


4147-8 


634 


592 


4161-3 


635 


593 


4174-7 


636 


594. 


4188*1 


637 


595 


4201-5 


638 


596 


4214-9 


639 


597 


4228-2 


640 


598 


4241-6 


641 


599 


4254-9 


642 


600 


4268-2 


643 


601 


4281-4 


644 


602 


4294-7 


645 


603 


4307*9 


646 


604 


4321-1 


647 


605 


4334-3 


648 


606 


4347*4 


649 


607 


4360-5 


650 


608 


4373-7 


651 


609 


4386-7 


652 


610 


4399-8 


653 


New Sc} 


ies. Vol. 


i. No. 21 



Metres. 

4412-8 

4425-9 

4438-9 

4451-9 

4464-8 

4477-7 

4490-7 

4503-6 

4516-4 

4529-3 

4542-1 

4554-9 

4567-7 

4580-5 

4593-2 

4606-0 

4618-7 

4631-4 

4644-0 

4656-7 

4669-3 

4682-0 

4694-5 

4707*1 

4719-7 

4732-2 

4744-7 

4757*2 

4769-7 

4782-1 

4794-6 

4807-0 

4819-4 

4831-7 

4844-1 

4856-4 

4868-7 

4881-0 

4893-3 

4905-6 

4917*8 

4930-0 

4942-2 



Milli. 


Metres. 


654 


4954-4 


655 


4966-6 


656 


4978-7 


657 


4990-9 


658 


5003-0 


659 


5015-1 


660 


5027*2 


661 


5039-2 


662 


5051-2 


663 


5063-3 


664 


5075-3 


665 


5087*2 


666 


5099-2 


667 


5111-2 


668 


5123-1 


669 


5135-0 


670 


5146-9 


671 


5158*8 


672 


5170-6 


673 


5182-5 


674 


5194-3 


675 


5206-1 


676 


5217-9 


67T 


5229-7 


678 


5241-4 


679 


5253-2 


680 


5264-9 


681 


5276-6 


682 


5288-3 


683 


5300-0 


684 


5311-6 


685 


5323-2 


686 


5334-8 


687 


5346-4 


688 


5358-0 


689 


5369-6 


690 


5381-1 


691 


5392-7 


692 


5404-2 


693 


5415-7 


694 


5427-2 


695 


5438-7 


696 


5450-1 



Sept, 1828. 2 D 



202 



M. Oltmanns' Tables for 
Table B. (continued.) 



Milli. 


Metres. 


Milli. 


Metres. 


Milli. 


Metres. 


697 


5461-5 


729 


5819-0 


761 


6161-1 


698 


5472-9 


730 


5829*9 


762 


6171*5 


699 


5484-3 


731 


5840-8 


763 


6182-0 


700 


5495-7 


732 


5851-7 


764 


6192-4 


701 


5507*1 


733 


5862-5 


765 


6202-8 


702 


5518-4 


734 


5873-4 


766 


6213-2 


703 


5529-8 


735 


5884-2 


767 


6223-6 


704 


5541-1 


736 


5895-1 


768 


6234-0 


705 


5552-4 


737 


5905*9 


769 


6244-4 


706 


5563-7 


738 


5916-7 


770 


6254-7 


707 


5575-0 


739 


5927-5 


771 


6265-0 


708 


5586-2 


740 


5938-2 


772 


6275-4 


709 


5597-5 


741 


5949-0 


773 


6285*7 


710 


5608-7 


742 


5959-7 


774 


6296-0 


711 


5619-9 


743 


5970-4 


775 


6306-2 


712 


5631-1 


744 


5981-2 


776 


6316-5 


713 


5642-2 


745 


5991-9 


777 


6326-7 


714 


5653-4 


746 


6002-5 


778 


6337*0 


715 


5664<'6 


747 


6013-2 


779 


6347*2 


716 


5675-7 


748 


6023*8 


780 


6357*4 


717 


5686-8 


749 


6034-4 


781 


6367*6 


718 


5697-9 


750 


6045-1 


782 


6377*8 


719 


5709-0 


.751 


6055-7 


783 


6388-0 


720 


5720-1 


752 


6066-3 


784 


6398*2 


721 


5731-1 


753 


6076-9 


785 


6408-3 


722 


5742-1 


754 


6087*5 


786 


6418-5 


723 


5753-1 


755 


6098-0 


787 


6428-6 


724 


5764-2 


756 


6108-6 


788 


6438-7 


725 


5775-1 


757 


6119-1 


789 


6448-8 


726 


5786-1 


758 


6129-6 


790 


6458-9 


727 


5797*1 


759 


6140-1 






728 


5808-0 


760 


6150*6 













Tabi 


.E C. 








Deg. 


Metre. 


Deg. 


Metre. 


Deg. 


Metre. 


Deg. 


Metre. 


0-£ 


0-3 


1-4 


2-1 


2-6 


3-8 


3-8 


5'6 


0-4 


0-6 


1-6 


2-3 


2-8 


4-1 


4-0 


5-9 


Of) 


0-9 


1-8 


2-6 


3-0 


4-4 


4-2 


6-2 


0-8 


1-2 


2-0- 


2-9 


3-2 


4-7 


4-4 


6-5 


10 


1-5 


2-2 


3-2 


3-4 


5-0 


4-6 


6-8 


m 


1-8 


2-4 


3'5 


3-6 


5'3 


4-8 


7'1 



calculating Heights by the Barometer. 
Table C. [continued.) 



203 



Deg. 


Metre. 


Deg. 


Metre. 


Deg. 


Metre. 


Deg. 


Metre. 


50 


7'4 


8-8 


12-9 


12-6 


18-5 


16-4 


24-1 


5*2 


7-6 


9-0 


13-2 


12-8 


18-8 


16-6 


24-4 


5-4 


7-9 


9-2 


13-5 


13-0 


19-1 


16-8 


24*7 


5-6 


8-2 


9*4 


13-8 


13*2 


19*4 


17-0 


25-0 


5-8 


8-5 


9-6 


14-1 


13-4 


19-7 


17-2 


25-3 


6-0 


8-8 


9-8 


14-4 


13-6 


20-0 


17-4 


25-6 


6-2 


9*1 


10-0 


14-7 


13-8 


20-3 


17-6 


25-9 


6-4 


9'4 


10-2 


150 


14-0 


20-6 


17*8 


26-2 


6-6 


9*7 


10-4 


15-3 


14-2 


20-9 


18-0 


26-5 


6-8 


10-0 


10-6 


15-6 


14-4 


21-2 


18-2 


26-8 


70 


10-3 


10-8 


15-9 


14-6 


21-5 


18-4 


27-1 


7'2 


10-6 


11-0 


16-2 


14-8 


21-8 


18-6 


27*4 


7*4 


10-9 


11-2 


16-5 


15-0 


22-1 


18-8 


27-7 


7-6 


11-2 


11-4 


16-8 


15-2 


22-4 


190 


28-0 


7*8 


11-5 


11-6 


17*1 


15-4 


22-7 


19-2 


28-2 


8-0 


11-8 


11-8 


17*4 


15-6 


22-9 


19-4 


28-5 


8-2 


12-1 


12-0 


17-6 


15-8 


23-2 


19'6 


28-8 


8-4 


12-4 


12-2 


17-9 


160 


23*5 


19-8 


29*1 


8-6 


12-6 


12-4 


18-2 


16-2 


23-8 







Table D. 



Approx. 
Height. 


0° 


5° 


10° 


15° 


20° 


25° 




m. 


m. 


m. 


m. 


m. 


m. 


200 


1-2 


1-2 


1-2 


1-0 


1-0 


10 


400 


2*4 


2-4 


2-4 


2-2 


20 


2-0 


600 


3-4 


3-4 


3-4 


3-2 


3-0 


2-8 


800 


4-5 


4-5 


4-5 


4-3 


4-1 


3-8 


1000 


5-7 


5-7 


5-7 


5-3 


5-1 


4-8 


1200 


7*0 


7*0 


6-8 


6-4 


6-0 


5-8 


1400 


8-2 


8-2 


8-0 


7-6 


7*1 


6-7 


1600 


9-2 


9*2 


9*0 


8-8 


8-2 


7-6 


1800 


10-4 


10-4 


10-2 


o-i 


9*4 


8-6 


2000 


11-6 


11-5 


11-3 


11-0 


10-4 


9-6 


2200 


12-8 


12-6 


12-6 


12-1 


11-4 


10-6 


2400 


14-0 


14-0 


13-8 


13-3 


12-5 


11-6 


2600 


15*2 


15-2 


15-0 


14-4 


13-6 


12-6 


2800 


16-6 


16-5 


16-4 


15-6 


14-8 


13-6 


3000 


17-9 


17-7 


17-6 


16-8 


15-8 


14-6 


3200 


19-1 


18-9 


18-7 


18-0 


17-0 


. 15-7 


3400 


.20-5 


203 


20- 1 


19'3 


18-4 


1 16-9 



2 D 2 



204 



M. Oltmanns' Tables for 
Table D. (continued.) 



Approx. 
Height. 


0° 


5° 


10° 


15° 


20° 


25° 




m. 


m. 


m. 


m. 


m. 


m« 


3600 


21-8 


21-7 


21-4 


20-4 


19*6 


18-0 


3800 


23-1 


22-9 


22-6 


21-6 


20-6 


19-1 


4000 


24-6 


24-4 


24-0 


22*9 


21-9 


20-3 


4200 


25-9 


25-7 


25-3 


24-3 


23-0 


21-6 


4400 


27-5 


27*3 


26-8 


25-8 


24-3 


23-0 


4600 


28-9 


28-7 


28-2 


27*1 


25-6 


24-3 


4800 


30-4 


30-2 


29-6 


28-4 


27*0 


25-5 


5000 


31-8 


31-6 


30-9 


29'8 


28-4 


26-7 


5200 


33-0 


32-8 


32-1 


31-0 


29*7 


28-0 


5400 


34-3 


34-1 


33-5 


32-4 


30-8 


29*2 


5600 


35-7 


35-5 


34-8 


33-7 


32-1 


30-2 


5800 


3M 


36-9 


36-1 


350 


33-2 


31-3 


6000 


38-5 


38-3 


37'5 


3&3 


34-3 


32-3 


Approx. 
Height. 


30° 


35° 


40° 


45° 


50° 


55° 




m. 


m. 


m. 


m. 


m. 


m. 


200 


0-8 


0-8 


0-6 


0-6 


0-6 


0-4 


400 


1-8 


1-7 


1-4 


1-2 


1-0 


0-8 


600 


2-6 


2-4 


2-0 


1-8 


1-6 


1*2 


800 


3-5 


3-1 


2-# 


2-4 


2-0 


1-7 


1000 


4-3 


3-8 


3-4 


3-1 


2-6 


2-2 


1200 


5-1 


4*6 


4-2 


3-6 


3-1 


2-6 


1400 


6-1 


5*4 


4-8 


4-2 


3-6 


3-0 


1600 


7-0 


6-2' 


5.6 


4-8 


4-1 


3-4 


1800 


8-0 


7-0 


6-3 


5-4 


4-6 


3-8 


2000 


8-8 


7-8 


7-0 


6-0 


5-1 


4-2 


2200 


97 


8-6 


7-6 


6-6 


5-6 


4-6 


2400 


10-6 


9*4 


8-4 


7-2 


6-1 


5-1 


2600 


11-6 


10-5 


9*2 


8-0 


6-8 


5-6 


2800 


12-6 


11-4 


10-0 


8-8 


7*4 


6-2 


3000 


13-6 


12-2 


10-8 


9-4 


8-0 


6-6 


3200 


14-6 


13-1 


11-5 


10-1 


8-6 


7-0 


3400 


15-7 


14-1 


12-4 


10-9 


9*2 


7-7 


3600 


16-7 


15-0 


13-4 


11-6 


9-8 


8-2 


3800 


17-7 


15-9 


14-3 


12-4 


10-5 


8-7 


4000 


18-7 


17-0 


15-1 


13-1 


11-2 


9-4 


4200 


19-9 


18-0 


15-9 


14-0 


12-0 


10-1 


4400 


21-1 


19*1 


16-9 


15-0 


12-9 


10-8 


4600 
1 4800 | 


22-3 


20-3 


18-0 


15-9 


13-6 


11-5 


23-4 


21-3 1 


19'0 


16-7 


14-3 


12-1 



calculating Heights by the Barometer. 
Table D. (continued.) 



205 



Approx. 
Height. 


30° 


35° 


40° 


45° 


50° 


55° 




m. 


in. 


m. 


m. 


m. 


m. 


5000 


24-6 


22*3 


19*9 


17*4 


15*0 


12-7 


5200 


257 


23-3 


20-8 


18-2 


15-7 


13-3 


5400 


26-7 


24*3 


21-7 


19-1 


16-4 


13-9 


5600 


27*8 


25-3 


22-6 


19*9 


17*2 


14-5 


5800 


28-9 


26-3 


236 


20-7 


17*8 


15-1 


6000 


30-0 


27*3 


24-6 


21-5 


18-5 


15-7 



Table E. 



h 


Metres. 


h 


Metres. 


400 


1-71 


600 


0-63 


450 


1*39 


650 


0-42 


500 


Ml 


700 


■ 0-22 


550 


0-86 


750 


0-03 



Let, for example, the height of the barometer at the lower 
station be = 600 millimetres ; the difference of level = 1500 
metres, we have 1000 : 0*63 = 1500 : 0*95, and the difference 
of the level corrected = 15*009 metres. This correction 
always added. 

Table F. 
Reduction of Metres into English Feet and Inches. 



is 



Metres. 


Feet. 


Inches. 


Metres. 


Feet. 


Inches. 


1 


3 


3-370 


60 


196 


10-217 


2 


6 


6-740 


70 


229 


7*920 


3 


9 


10-111 


80 


262 


5-623 


4 


13 


1-481 


90 


295 


3-326 


5 


16 


4-851 


100 


328 


1-029 


6 


19 


8-222 


200 


656 


2-058 


7 


22 


11-592 


300 


984 


3-087 


8 


26 


2-963 


400 


1312 


4-116 


9 


29 


6-333 


500 


1640 


5-145 


10 


32 


9-702 


600 


1968 


6-174 


20 


65 


7-405 


700 


2296 


7-203 


30 


98 


5-108 


800 


2624 


8-232 


40 


131 


2-811 


900 
| 1000 


2952 


9-261 


50 


164 


0-514 


3280 


10-290 



206 Prof. Gauss on the Representation of the Parts 
Table F. (continued.) 



Metres. 


Feet. 


Inches. 


Metres. 


Feet. 


Inches. 


2000 


6561 


8-58 


7000 


22966 


0-03 


3000 


9842 


6-87 


8000 


26246 


10-32 


4000 


13123 


5-16 


9000 


29527 


8-61 


5000 


16404 


3-45 


10000 


32808 


6-90 


6000 


19685 


1-74 









Reduction of Decimetres, Centimetres, and Millimetres, to 



English Inches. 



Dec. 


Inches. 


Cent. 


Inches. 


Milli. 


Inches. 


1 


3-937 


1 


0*393 


1 


0-039 


2 


7-874 


2 


0-787 


2 


0-078 


3 


11-811 


3 


1-181 


3 


0-118 


4 


15-748 


4 


1-574 


4 


0-157 


5 


19-685 


5 


1-968 


5 


0-196 


6 


23-622 


6 


2-362 


6 


0-236 


7 


27*559 


7 


2-755 


7 


0-275 


8 


31-496 


8 


3-149 


8 


0-314 


9 


35-433. 


9 


3-543 


9 


0-354 


10 


39*370 


10 


3-937 


10 


0-393 



XXXV. General Solution of the Problem : to represent the 
Parts of a given Surface on another given Surface, so that the 
smallest Parts of the Representation shall be similar to the cor- 
responding Parts of the Surface represented. By C. F. Gauss. 
Answer to the Prize Question proposed by the Royal Society 
of Sciences at Copenhagen. 

[Concluded from p. 113.] 

12. AS a fourth example, we will consider the represen- 
•*•"■ tation of the surface of an ellipsoid of revolution in 
a plane. Let a and b be the two principal semiaxes of the el- 
lipsoid, so that we may put x — a cos / sin u, y=a sin / sin u, 
z —b cos u. We shall then have 

& = a 2 sin u* dt 2 + (a 2 cos u 2 -\- b 2 sin «*) d u 2 
and the differential formula w = gives, if we put for brevity 

*/(l ^\ = s (b being supposed <a), 

= dt + idu >v/(cotang w 2 +l— e 2 ). 

Putting 



of a given Surface on another given Surface. 207 

Putting now */{\ — e 2 ) . tang u = tang co (when applied to 
the terrestrial spheroid 90— co will be the geographical lati- 
tude and t the longitude), the equation will assume this form : 

= at + idea . - — -r—. — , 

(1 — j^cos*^) sin« ' 

the integration of which gives 

const. = t ± Hog I cotang J co . (i^ii^L) ' \ . 

Consequently f denoting an arbitrary function, we have to 
take for X the real, and for i Y the imaginary part of 

/(« + ,- kg \ cotang kirlggfii 

If a linear function is chosen for f, putting^u = k v 9 we shall 
have 

X = kt, Y = h log cotang \ co— \ k s log + tcoSft, ? 

which is a projection analogous to that of Mercator. 

If on the contrary an imaginary exponential function is 
taken foryj we have 

X = £ tang ) co (j— c — { .cos X*, 

Y = £ tang |co ( -tZTSnr l sm X * 

which putting A = 1 will give a projection analogous to the 
stereographical, and generally one which is very proper for 
representing a portion of the earth's surface if the ellipticity 
is to be taken into consideration. 

The formulae for the other case in which b>a may be im- 
mediately derived from the preceding ones ; the same notation 

being retained, e will become imaginary, but ( _ * °° s - y will 

again become real. But for the sake of completeness we will 
separately develope the formulae for this case, and first put 

\f ( — — l)=i). We then determine co by the equation 

s/{\ + >j 2 ) . tang u = tang co, and the differential equation 

= dt + id co. ,, , " - — r-: — has for its integral, the fol- 

( 1 -J- «* cos •>*■*) sin u ° 

lowing : 

Const. = t + i (log cotang \ co + vj. arc tang *j . cos co) so that 
X will be the real and iY the imaginary part of 

f [t + * log (cotang J co -f *j . arc tang >j . cos co)} 

From 



208 Prof. Gauss on the Representation of the Parts 

From this expression may be immediately derived the for- 
mulae for tliis case corresponding to those above given for the 
particular suppositions made for the function f. 

In the first supposition we shall have to take 
X = kt 9 Y=z k log cotang £ # -f- »j k arc tang y . cos » 
In the second case 

X = k tang i **«jr "$« ten S ■ • cos » . cos A t 

Y = k tang ico X .e- vXaTCt&net, ' :coS6 ' .sin \t. 

13. Lastly, we will consider the general representation of 
the surface of an ellipsoid of revolution on the surface of a 
sphere. For the latter we will retain the solution of the pre- 
ceding article, and put the radius of the sphere = A, and 
X = A cos T . sin U, Y = A sin T . sin U, Z = A . cos U. 

Applying the general solution of art. 5. we shall find, f de- 
noting an arbitrary function, that T must be made equal to 
the real, and i log cotang \ U to the imaginary part of 

/(^noglcotang^^^i^fl)*. 

The supposition fv = v will give the simplest solution, by 
which will be 

T = Man g 4U = tangJ a) .(i±if^) i ' 

This presents a transformation exceedingly useful in higher 
geodetics ; on the application of which we can, however, give 
in this place only a few short hints. If we regard as corre- 
sponding points on the surface of the ellipsoid and the sphere 
those which have the same longitude, and whose latitudes 
90°— U, 90°— on respectively are connected together by the 
above-given equation, we shall have for a system of compara- 
tively small triangles (as those which can serve for real measure- 
ment must always be) which are formed by shortest lines on 
the surface of a spheroid, a corresponding system of triangles 
on the surface of the sphere whose angles are exactly equal to 
the corresponding ones on the spheroid, and the sides of which 
deviate so little from arcs of greatest circles, that in most cases 
where the very extreme of accuracy is not required, they may 
be supposed to coincide with them ; and even where such 
extreme accuracy is required, the deviation from parts of 

* We pass over the second solution of art. 5. which is distinguished from 
the above by a substitution of — T for -f-T only, and which would give a 
reversed representation ; and we pass likewise over the case of an oblong 
spheroid , which, agreeably to the treatment of the analogous case in the 
preceding article, results immediately from that of the oblate spheroid. 

greatest 



of a given Surface on another given Surface. 209 

greatest circles may be calculated with any accuracy that may 
be necessary by simple formulae. It is therefore possible to 
calculate the whole system, one side of a triangle having first 
been duly transferred to the spherical surface, by the angles, 
entirely as if the whole were on the sphere itself, with the 
modification just indicated, if necessary ; for all points of the 
system the values of T and U may be determined, and we 
may go back from the latter to the corresponding values of eo 
(in the simplest manner by an auxiliary table of very easy 
construction). A triangulation never embracing more than 
a very moderate portion of the surface of the earth, the 
above-mentioned purpose may be still more perfectly accom- 
plished if we generalize the preceding solution by putting 
fv = v + const, instead of fv as v. Clearly nothing would 
be gained by this supposition, if a real value were assigned to 
the const, as T and t would then only differ by this constant 
quantity ; and consequently, the points from which the longi- 
tudes are counted would only be different. But the result is 
very different, if we assign to the constant quantity an ima- 
ginary value. If we put it =s i log k, we have 

T = t, tang J U = k tang \ m . (>£££)* 

In order to decide on the appropriate value of k, it is neces- 
sary first to determine the scale of the representation. 

In conformity to the notation of articles 5 and 6, we have 

n = a 2 sin u 2 , N = A 2 sin U 2 , $v — 1 

, A sin U A sin U , , _ „ „x 

hence m = -. — = — : . v (1— s cos or) «= 

a . sin u a sin u v 

A ft(l-£3cosfi>3)£-H* 

a cos§«' 2 (l — i cos*.) 8 -f-&2 sin£«2(i_j_ £ cosa/) e 

The scale, therefore, depends on the latitude only. The 
smallest possible deviation from perfect similarity is obtained 
by such a determination of k as will give equal values of m 
for the extreme latitudes, by which the value of m for the 
mean latitude will be nearly a maximum or a minimum. If 
we denote the extreme values of m by co° and a/, we obtain in 
this manner 

COS£»°2(l-£COSft/°) S COS$*/3(l -i COS*/) 6 

, (1 - i» cos fli°Q § + § ' (l-s^cosa/^i + f ' 

~~ sin§o^(l-|-£COS*/) £ sin§6^(l-f£Cos«°) £ 

(l-t^cos*")^* 1 (l-s'cosa^f+i* 

New Series. Vol. 4. No. 2 1 . Sept. 1 828. 2 E In 



= (— 

\i+» 



210 Prof. Gauss on the Representation of the Parts 

In order to ascertain for which latitude m has its greatest 
or smallest value, we have 

dm TT JTT , . & cos u. sin u.du 

= cotang U . aU — cotang co . dco ^ ■ — 

m ° ° 1— «*cos«* 

rf U, d * «* sin « . d u ( 1 — t 2 ) f/ w 

sin U sin « 1 — i^cos*^ ~~ (1 — t'*cos v*) sin a* 

and hence, — r= . ( *"" a ., ■ (cos U — cos co). 

wt sin 4/(1— t 2 cos» i v ' 

It is clear from this that m obtains its greatest or smallest 
value when U = co; if we denote this value of w by W, we 
shall have 

l-«cok W\*« - 17 . \-k7 , , . , ~ XT 

rrr ) » Ol', COS W = by which W 

cos vv / * J 

'(i+tO 

may be determined if & is calculated by the above formula. 
In practice, however, the perfect equality of the values of m 
for the extreme latitudes will be of little moment, and it will 
be sufficient to take for 90 — W nearly the middle latitude, 
and to derive k from it. The general connexion between U 
and u) is given by this equation 

i TT , i ( (l-«cosW)(l+scos«) )*' 

tang $ U as tang £ m. I j— '), 7 \ 

I ° I (1+* cos W) (1 — i cosu) ) 

For a real numerical calculation it is, however, more advan- 
tageous to apply series which may receive different forms, but 
the development of which we shall not here stop to investigate. 
As it will be easily seen that for co< W, will be U>co, 

d m 

therefore, cos U— cos co, and consequently likewise nega- 
tive, and that for a>>W we have U<co, and consequently 
-^- positive, it is evident, that for 00 = U = W the value of 

m is always a minimum and = — ^ (1 — e 2 cos W 2 ). If the 
radius of the sphere A is therefore assumed 



V^-^cosW')' 

the representation of infinitely small parts of the ellipsoid in 
latitude 90 — W is not only similar, but also equal to the ori- 
ginal, but in other latitudes larger. 

The logarithms of m may be developed with advantage in 
a series of ascending powers of cos U— cos W, the first terms 
of which will be sufficient for practice, and are as follow : 

Log hyp. m = log j ~ y^l - £ 2 cos W 2 ) \ + £vkl>y ( C0S U 

-cos W) 2 - ggjjk (cos U-cos W) 3 

If 



of a given Surface on another given Surface. 211 

If, for example, the kingdom of Denmark between the limits 
of latitude 53° and 58° is transferred in this manner to the 
surface of a sphere, and W is made = 34° 30', the representa- 
tion will, for the ellipticity 7 £ 7 , have its linear dimensions near 
the extreme latitudes increased by only j^Voo* We must 
content ourselves in this place with having given only a short 
description of this one method of employing the transfer of 
figures in higher geodetics, and must reserve a more detailed 
explanation for another place. 

14. It now remains to take into more close consideration a 
circumstance which presents itself in our general solution. 
We have shown in article 5, that there are always two solu- 
tions ; as P + i Q must either be a function ofp + i q, and P — i Q 
a function ofp—iq, or P-\-iQ a function ofp — iq 9 and P — iQ 
a function of p—iq* We will now prove that in the one so- 
lution the parts of the representation have a similar position 
as in the original ; whereas in the other they have a reversed 
position, and we will ,at the same time give a criterion by 
which this may be ascertained a priori. 

We observe in the first place, that the distinction between 
a perfect and a reversed similarity can only come into consi- 
deration if we make a distinction between the two sides of a 
surface by regarding the one as the upper, and the other as 
the lower one. As this is something arbitrary in itself, the 
two solutions are not essentially different, and a reversed simi- 
larity becomes a perfect one as soon as the side of one surface 
which was regarded as the lower one is considered as the 
upper one. This distinction could therefore not present it- 
self in our solution, as the surfaces were only determined by 
the coordinates of their points. If this circumstance is to be 
taken into consideration, the nature of the surfaces must first 
be established in a manner which shall involve this circum- 
stance. With this view we will assume that the nature of the 
first surface is determined by the equation \J/ = 0, where 4> is 
a given uniform function of x, y 9 z. In all points of the sur- 
face the value of \J/ will, therefore, vanish ; and in all points of 
space not belonging to the surface, it will not vanish. In a 
transition through the surface, vj/ will therefore, at least gene- 
rally speaking, pass from a positive value to a negative one ; 
while a transition in a contrary direction will change the ne- 
gative values of \J/ into positive ones, or on one side of the 
surface the values of \[/ will be positive, on the other negative. 
Let us regard the former as the upper, the latter as the lower 
side. The same may be assumed with regard to the second 
surface, which is determined by the equation * = 0, where * 

2E2 is 



212 Prof. Gauss on the Representation of the Parts 

is a given uniform function of the coordinates X, Y, Z. Let 
us suppose that we obtain by differentiation 

dty = edx+gdy+hdz 
rf* = EtfX + GrfY + H</Z. 
where e, g 9 h will be functions of x, y, z, and E, G, H functions 
ofX,Y,Z. 

The considerations by which we must reach the end here 
proposed being, although by no means difficult, yet of rather 
an uncommon kind, we shall endeavour to give to them the 
greatest possible perspicuity. Between the two corresponding 
representations on the surfaces whose equations are \[/ = 0, 
and * = 0, we will assume six intermediate representations 
or planes, so that eight representations will come under con- 
sideration ; viz. Considering as corre- 

sponding the points 
whose co-ordinates 
are respectively = 

1. The original on the surface, the equa- 1 

tion of which is v(/ = j <r '*^' 

2. The representation in the plane x 9 y, 0. 

3. t, u, 0. 

*• pi q, o. 

5. P,Q,o. 

6. T,U,0. 

7. X,Y,0. 

8. The representation on the surface, the \ v y 7 
equation of which is * = J ' ' * 

We will now compare these different representations merely 
with regard to the relative position of the infinitely small linear 
elements, without any regard to the relative magnitude, and 
we shall consider two representations as similarly situated, if of 
two elements proceeding from the same point, the one to the 
right, in one representation has its corresponding element in 
the other, likewise to the right ; in the contrary case, we shall 
call them reversed. In the plane from No. 2 to No. 7, that 
side on which are the positive values of the third coordinate 
is considered as the upper one, but in the cases of the first 
and last surfaces the distinction between upper and lower side 
depends only on the positive and negative values of ty and * 
as has been before explained. 

Now it is in the first place clear, that for each place of the 
first surface where, x and y remaining the same, a positive in- 
crement of z carries to the upper side, the representation 2 
will be similarly situated with the representation 1 ; this will 

evidently 



of a given Surface on another given Surface. 213 

evidently happen whenever h is positive, and the contrary will 
take place when h is negative ; in which case the representa- 
tions will have reversed positions. 

In the same manner the representations in 7 and 8 will be 
similarly or reversedly situated, according as H is positive or 
negative. 

In order to compare together the representations in 2 and 3, 
let in the first, d s be the length of an infinitely small line from 
the point whose co-ordinates are x, y, to another whose co- 
ordinates are x + dx, y + dy 9 and let / be its inclination to the 
line of abscissas increasing in the same direction in which we 
turn from the axis of the x to that of the y, therefore dx = ds 
cos /, dy =s ds . sin /. In the representation 3, let dcr be the 
length of the line corresponding to d s, and its inclination to 
the line of abscissae in the same sense as before, A so that d t 
= da- . cos A, d u = d or . sin A. We have, therefore, in the 
notation of the 4th article, 

ds . cos I = da- (a cos A-f «' sin A) 

ds . sin I = d a- (b cos A + 6' sin a), consequently 

, b . cos X 4- b' sin A. 

tang I — . , . . 

P a . cos X + a sin X 

If x and y are now considered as constant, and Z, A as variable 
quantities, the differentiation gives 

dl __ ab'—a'b . ,,__ ,,. do* 

dk (acos A-|-a'sinA) ,i -)-(6cosX-+-&'sin x) 2 ' '* ds* 

It is therefore evident that, according as ab'—ba' is positive 
or negative, I and A will increase at the same time, or their va- 
riations will have contrary signs ; and that in the first case the 
representations 2 and 3 will be similarly situated, in the other 
they will be reversed. 

Combining this result with the one found above, we per- 
ceive that the representations in 1 and 3 will be similarly si- 
tuated or reversed, according as — is positive or nega- 
tive. As on the surface, whose equation is ty = 0, we have 
edx +g dy + kdz = i therefore, likewise (e a +g b + hc) dt 
+ (e a' -\-gb l + he') d u = ; whatever ratio for dt and du may 
be chosen, the following quantities must be identically zero, 

ea+gb + hc-=. 0, ea'+gb'+hc ! = 

from which it follows that e,g, h must be respectively propor- 
tional to the quantities bd—cb 1 , caJ—ad, ab'—ba', therefore 

bc'—cb' ca'.—ac ab'—ba 

e g k 

. any one of these three expressions, or if we multiply by the 

quantity 



214? Prof. Gauss on the Representation of a Surface. 

quantity e*+g*-\-h 2 which is necessarily positive, the sym- 
metrical quantity resulting from that multiplication, 

abd +gcd -\-haV—ecb ] —gad—hba\ may be applied 
as a criterion of a similar or reversed position of the parts in 
the representations 1 and 3. 

In the same manner the similar or reversed position of the 
parts in the representations 6 and 8 may be proved to depend 

on the positive or negative value of the quantity — ^ = 

CA'-AC AB'-BA' .- . , 
- = - , or the symmetrical quantity 

EBC' + GCA' + HAB'-ECB'-GAC'-HBA'. 

The comparison of the representations in S and 4* depends 
on similar principles as that of 2 and 3, and the similar or re- 
versed position of the parts depends on the positive or nega- 

tive sign of the quantity (Jt ) . (£) - (£ ) . (i? ), and 

in like manner the positive or negative sign of 

/<*P\ /<*Q\ / <*P\ /£Q\ 

\dT /'\dU / \dV J'\dT ) 
will determine the similar or reversed position of parts in the 
representations 5 and 6. 

With regard to the comparison of the representations 4 
and 5, we may refer to the analysis of the 8th article, from 
which it will be clear that these will be similar or reversed in 
their smallest parts, according as the first or second solution 
is adopted, that is, according as either, we have made 

P + *Q z=fp + iq, and P — i Q —f\p — iq\ or 
P + ,'Q =f(p-iq), and P-iQ =f(p + iq). 
From all that precedes, we now draw the conclusion that if 
the representation on the surface, whose equation is $• = 0, is 
to be in the smallest parts, not only similar, but likewise si- 
milarly situated to the original in the surface, whose equation 
is \f/ = 0, we must regard the number of negative quantities 
which will be found among these four quantities 

ab-baf / d P\/ d 9\ ( d P \ ( d l_\ / dP V^\ 
h 9 \dt/\du/ \du/'\ dtj' \dT/\dU~/ 

(tu") ( 7t )' — i — ; if tnere 1S none > or an even number 
of them, the first solution must be taken ; but if there is one, 
or if there are three negative quantities among them, the se- 
cond solution must be adopted. By a contrary choice a re- 
versed similarity will always take place. 

It may besides be demonstrated that if we designate the 

above 



Mr. Graham on the Influence of the Air in Crystallization, 215 
above four quantities respectively by r, s, S, R, we shall always 

have 1W±£±»L= + n , H^P+GH-H.) = + y 
s o 

n and N having the signification of article 5 : we pass, however, 
over the demonstration of this theorem, which it is not diffi- 
cult to find, as it is not further necessary for our purpose. 



XXXVI. On the Influence of the Air in determining the Cry- 
stallization of Saline Solutions. By Thomas Graham, Esq. 
AM. F.R.S. E* 

T^HE phenomenon referred to has long been known, and 
■*' popularly exhibited in the case of Glauber's salt, without 
any adequate explanation. A phial or flask is filled with a 
boiling saturated solution of sulphate of soda or Glauber's 
salt, and its mouth immediately stopped by a cork, or a piece 
of bladder is tied tightly over it, while still hot. The solution, 
thus protected from the atmosphere, generally cools without 
crystallizing, although it contains a great excess of salt, and 
continues entirely liquid for hours and even days. But upon 
withdrawing the stopper, or puncturing the bladder, and ad- 
mitting air to the solution, it is immediately resolved into a 
spongy crystalline mass, with the evolution of much heat. The 
crystallization was attributed to the pressure of the atmosphere 
suddenly admitted, till it was shown that the same phenomenon 
occurred, when air was admitted to a solution already subject 
to the atmospheric pressure. Recourse was likewise had to 
the supposed agency of solid particles floating in the air, and 
brought by means of it into contact with the solution ; or it 
was supposed that the contact of gaseous molecules themselves 
might determine crystallization, as well as solid particles. But 
although the phenomenon has been the subject of much spe- 
culation among chemists, it is generally allowed that no satis- 
factory explanation of it has yet been proposed. 

In experimenting upon this subject, it was found that hot 
concentrated solutions, in phials or other receivers, might be 
inverted over mercury in the pneumatic trough, and still re- 
main liquid on cooling ; and thus the causes which determine 
crystallization were more readily examined. For this pur- 
pose, it was absolutely necessary that the mercury in the trough 
should be previously heated to 110° or 120°; for otherwise 
that part of the solution in contact with the mercury cooled 
so rapidly, as to determine crystallization in the lower part of 

* From the Transactions of the Royal Society of Edinburgh ; but re- 
vised by the Author for the Phil. Mag. and Annals. 

the 



216 Mr. Graham on the Influence of the Air in determining 

the receiver long before the upper part had fallen to the tem- 
perature of the atmosphere. In such cases, crystallization 
beginning on the surface of the mercury, advanced slowly and 
regularly through the solution. Above, there always remained 
a portion of the solution too weak to crystallize, being im- 
poverished by the dense formation of crystals below. It was 
also necessary to clean the lower and external part of the 
receivers, when placed in the trough, from any adhering so- 
lution, as a communication of saline matter was sometimes 
formed between the solution in the receiver and the atmo- 
sphere without. When these precautions were attended to, 
saline solutions over mercury remained as long without cry- 
stallizing as when separated from the atmosphere in the usual 
mode. 

Solutions which completely filled the receivers when placed 
in the trough, allowed a portion of mercury to enter, by con- 
tracting materially as they cooled. A bubble of air could thus 
be thrown up, without expelling any of the solution from the 
receiver, and the crystallization determined, without exposing 
the solution directly to the atmosphere. 

The first observation made was, that solutions of sulphate 
of soda sometimes did not crystallize at all upon the intro- 
duction of a bubble of air, or at least for a considerable time. 
This irregularity was chiefly observed in solutions formed at 
temperatures not exceeding 150° or 170°, although water dis- 
solves more of the sulphate of soda at these inferior tempera- 
tures than at a boiling heat. Brisk ebullition for a few se- 
conds, however, rendered the solution upon cooling amenable 
to the usual influence of the air. In all successful cases, cry- 
stallization commenced in the upper part of the receiver around 
the bubble of air, but pervaded the whole solution in a very 
few seconds. A light glass bead was thrown up into a solu- 
tion without disturbing it. 

It occurred to me, that, since the effect of air could not be 
accounted for on mechanical principles, it might arise from a 
certain chemical action upon the solution. Water always holds 
in solution a certain portion of air at the temperature of the 
atmosphere, which it parts with upon boiling. Cooled in a 
close vessel after boiling, and then exposed to the atmosphere, 
it reabsorbs its usual proportion of air with great avidity. 
Now, this absorbed air appears to affect in a minute degree 
the power of water to dissolve other bodies ; at least a con- 
siderable part of it is extricated upon the solution of salts. 
When a bubble of air is thrown up into a solution of sulphate 
of soda, which has previously been boiled and deprived of all 
its air, a small quantity of air will certainly be absorbed by 

the 



the Crystallization of Saline Solutions. 217 

the solution around the bubble. A slight reduction in the 
solvent power of the menstruum will ensue at the spot where 
the air is dissolved. But the menstruum is greatly overloaded 
with saline matter, and ready to deposit ; the slightest diminu- 
tion of its solvent power may therefore decide the precipitation 
or crystallization of the unnatural excess of saline matter. The 
absorption of air may in this way commence and determine the 
precipitation of the excess of sulphate of soda in solution. 

Here, too, we have an explanation of the fact just mentioned, 
that solutions of sulphate of soda which have not been boiled, 
are less affected by exposure to the air than well-boiled solu- 
tions ; for the former still retain the most of their air, and do 
not absorb air so eagerly on exposure as solutions which have 
been boiled. 

But the theory was most powerfully confirmed by an expe- 
rimental examination of the influence of other gases, besides 
atmospheric air, in determining crystallization. Their in- 
fluence was found to be precisely proportionate to the degree in 
which they are absorbed or dissolved by water and the saline 
solutions. 

To a solution of sulphate of soda over mercury, which had 
not been affected by a bubble of atmospheric air, a bubble of 
carbonic acid gas was added. Crystallization was instantly 
determined around the bubble, and thence through the whole 
mass. Water is capable of dissolving its own volume of car- 
bonic acid gas, and a solution of sulphate of soda as strong as 
could be employed was found by Saussure to absorb more 
than half its volume. 

In a solution of sulphate of soda, which was rather weak, 
both common air and carbonic acid gas failed to destroy the 
equilibrium ; but a small bubble of ammoniacal gas instantly 
determined crystallization. 

When gases are employed which water dissolves abundant- 
ly, such as ammoniacal and sulphurous acid gases, the cry- 
stallization proceeds most vigorously. It is not deferred till 
the bubble of gas reaches the top of the receiver, as always 
happens with common air, and frequently with carbonic acid 
gas, but the track of the bubble becomes the common axis of 
innumerable crystalline planes, upon which it appears to be 
borne upwards ; and sometimes before the ascent is completed, 
the bubble is entangled and arrested by crystalline arrange- 
ments which precede it. 

The number of gases which are less soluble in water than 
atmospheric air is not considerable ; but of these, hydrogen gas 
was found to be decidedly least influential in determining cry- 
stallization. 

New Series. Vol. 4. No. 21. Sept. 1828. 2 F Minute 



218 Mr. Nixon on Rater's Horizontal Floating Collimator 



s 



Minute quantities of foreign liquids soluble in water like- 
wise disposed the saline solution to immediate crystallization, 
as might be expected, and none with greater effect than al- 
cohol. It is known that alcohol can precipitate sulphate of 
soda from its aqueous solutions. The soluble gases I suppose 
to possess a similar property. 

These facts appear to warrant the conclusion, that air de- 
termines the crystallization of supersaturated saline solutions, 
by dissolving in the water, and thereby giving a shock to the 
feeble power by which the excess of salt is held in solution. 

%* Since the foregoing observations were printed, the 
author has perceived that M. Gay-Lussac, in his paper on 
crystallization, (Ann. de Chim. torn, lxxxvii.) had distinctly 
thrown out the same theory as a conjecture, although the cir- 
cumstance is not noticed by any systematic chemical writer., 
But as M. Gay-Lussac brings forward no experimental illus- 
tration of the theory, and indeed adduces one experiment as 
unfavourable to it, the experimental confirmation of the theory 
is novel, and was certainly required. 



XXXVII. Method of avoiding certain sources of inaccuracy 
in the use of Kater's Horizontal Floating Collimator. By 
J. Nixon, Esq. 

To the Editors of the Philosophical Magazine and Annals. 
Gentlemen, 
TN making use of the horizontal floating collimator of Capt. 
■*- Kater, in order to determine the error of collimation of the 
telescope of a mural circle, it is necessary to place the colli- 
mator first to the north and afterwards to the south of the 
circle. In addition to the consequent probable source of 
error, as pointed out by Capt. Kater, may we not enumerate 
the following? 

1. In passing from the north, through the zenith to the 
south, the telescope describes an arc, which, from its magni- 
tude, may give rise to a sensible error in the graduation. 
2. The telescope, unless quite uniform in its parts, may have 
its flexure varied in consequence of being inverted in position ; 
in which event, the error of collimation will not be the same 
with the telescope pointed to the north as when directed to- 
wards the south. 3. When the north and south sides of the 
observatory are not uniform in temperature, is it not possible 
that the difference may vitiate the observations ? 

All these sources of inaccuracy and doubt may be avoided, 
and the observations completed with the telescope of the cir- 
cle 



Mr. Gray's Description of a new Kind of Pear-Encrinite. 219 

cle in one direction, by the addition of a telescope fixed on 
a support at such a distance from the circle that the collimator 
maybe conveniently placed between, and in a line with, the two 
telescopes. To find the error of collimation with the telescope 
of the circle directed towards the north, proceed as follows : 

1. The line of collimation of the telescope of the collimator 
being very nearly horizontal, place the instrument, with its 
telescope looking to the south, to the north of the mural circle. 
2. Make the line of collimation of the telescope of the circle, 
(pointing northwards,) parallel to that of the telescope of the 
collimator, and read off the (minute) angle of elevation or 
depression. 3.. Turn the collimator half reund in azimuth, 
when its telescope (pointing northwards) should be in a line 
with the fixed telescope placed to the north of the collimator. 
Make the line of collimation of the fixed telescope, pointing 
southwards, parallel to that of the telescope of the collimator. 
4. Remove the collimator, and measure by the micrometer of 
the fixed telescope the vertical angle formed by the intersec- 
tion of its line of collimation by that of the telescope of the 
circle ; half of which angle is the correct horizontal inclina- 
tion of the line of collimation of the telescope of the circle*. 

Having thus determined the northern error of collimation, 
we may subsequently ascertain, after the same method, the 
southern one ; and on comparing these errors with that given 
by the vertical collimator with the telescope pointed towards 
the zenith, we obtain the horizontal flexure of the telescope 
for both directions. I am, Gentlemen, yours, &c. 

Leeds, Aug. 2, 1828. John Nixon. 



XXXVIII. Description of a newKind o/ % Pear-Encrinite i /c>ttwe? 
in England. By John Edw. Gray, Esq. F.G.S.Sfc.f 

Encrinites (Apiocri?iites) Prattii, n. 

Specific Character : — /COLUMN formed of round joints ad- 
^^ hering by radiating surfaces.? of 
which the 4? or 5 top ones gradually enlarge at the apex, and 
sustain the pelvis, &c. 

Icon. n. Inhab. Lias, summit of Lansdown, near Bath. 
J. S. Pratt, Esq. Mus. Brit. 
This species appears to be intermediate between A. rotundus 
and A. cllipticus of Miller, and for the sake of comparison 
I have given the specific character after his method. 

* This angle will be an elevation, or a depression, according as the line 
of collimation of the fixed telescope points above, or below that of the 
telescope of the circle. f Communicated by the Author. 

2 F 2 The 



220 Notices respecting New Books. 

The column is thin, composed of short cylindrical joints, but 
the articulating surfaces are not distinctly seen in the speci- 
men under examination ; the enlarged apex is reversed coni- 
cal, formed of 5 joints, the basal one is very small, and thin ; 
the second, third and fourth, each gradually larger and thicker : 
the fifth is nearly of the same height, but rather larger in dia- 
meter, and the upper part is divided into 5 articulating sur- 
faces, each marked with five radiating grooves, and finely cre- 
nated on the margin. The pelvic plate small, wedge-shaped ; 
the outer edge is pentangular, outer sides very short. The 
first and second set of costals are broad and nearly equal ; 
the scapulars arfi as thick as the costals in the centre, and 
shelving on each side ; the arms, two from each scapular, com- 
pressed, each furnished with a double series of thin jointed 
filiform tentacula, the first joints of the arm are similar to the 
first costals, and the joints of the appendages are thin and 
compressed, similar to those in the arms of Comatula. 

In the above description I have adopted the name of the 
parts used by Miller. For the knowledge of this species I am 
indebted to the kindness of Mr. J. S. Pratt of Bath, by whom 
it was found. The specimen is placed in the collection of the 
British Museum. And I have ventured to name the species 
after that gentleman, although he disclaims being the first dis- 
coverer of it : but I consider that he is justly deserving of the 
honour, as being the first person who enabled it to be made 
public, and presented a specimen for the purposes of science 
to the National Collection. 



XXXIX. Notices respecting New Booh. 

A Popular Sketch of Electro- Magnetism, or Electro-Dynamics ; ivitk 
Plates of the most improved apparatus for illustrating the principal 
phcenomena of the science ; and outlines of the parent sciences Elec- 
tricity and Magnetism. — By Francis Watkins, Curator of Phi- 
losophical Instruments in the University of London. London, 8vo. 
pp. 83. Three plates. 

THIS work, we believe, is the first attempt that has been made 
to give a popular, and at the same time a comprehensive view 
of the new science of electro-magnetism. The notices of this 
science given in some of our elementary works on natural philoso- 
phy and chemistry, are necessarily brief and partial; and Professor 
Cumming's translation of Demontferrand's Manuel d 1 Electricite Dy- 
namique, is adapted chiefly to the use of those who are accustomed 
to mathematical expressions. The writer of this " Popular Sketch " 
therefore, deserves commendation for having thus endeavoured to 
make this beautiful and interesting department of knowledge, a 

branch 



Notices respecting New Books* 221 

branch of popular science. The prefatory outlines of electricity 
and magnetism are drawn up in a satisfactory manner; and the 
Sketch of Electro-Magnetism itself, gives a clear and connected de- 
tail of the principal observations and results of experiment, of which 
the science at present consists, with an account of the various ex- 
periments themselves, and directions for their performance. At 
the close of the work is given a description of a series of apparatus 
for exhibiting the most striking phenomena of electro-magnetism, 
illustrated by three engravings in outline, by Turrell. 

There can be no doubt but that a second edition of this useful lit- 
tle work will be called for; and when such is the case, we hope it will 
be carefully revised prior to republication; for there are some inaccu- 
racies in construction and language, and also in the occasional allu- 
sions to the objects of chemistry and other sciences connected with 
the subjects it explains, which, although they do not interfere with 
the main utility of the work, are yet likely to mislead the student 
in several minor, but still important points. We think, also, that it 
would be preferable to incorporate the description of the electro- 
magnetical instruments with the body of the work, giving each in- 
strument in its proper place, as illustrating a certain part of the 
science ; and in this case, engravings on wood inserted in the pages 
should be substituted for the plates, as uniting greater facility of 
reference, with equally satisfactory representation of the apparatus. 
These remarks are made entirely with the view to the future im- 
provement of what we consider a very useful contribution to scienti- 
fic literature; and we hope the sale of the work will be such as to 
encourage the writer to proceed in his endeavours to render the 
study of electro-magnetism accessible to every class of inquirers into 
the phenomena of Nature. It possesses one merit in particular, 
in which elementary works are too often deficient, —that of citing 
original and first-rate authorities on the subjects of which it treats, 
instead of referring only to compendiums and compilations. Every 
person, already possessing some elementary notions of experimental 
philosophy, may obtain from the perusal of Mr. Watkins's treatise, 
and the performance of the experiments described in it, a good ge- 
neral knowledge of electro-magnetic phaenomena, and become pre- 
pared for the study of the works in which their intimate nature is 
investigated. 

We must not, however, conclude this notice, without adverting 
to Mr. Watkins's remarks on the experiments of Professor Mori- 
chini and Mrs. Somerville, in which steel, in various forms, exposed 
to the more refrangible rays of the solar spectrum, acquired magne- 
tic polarity. Mr. Watkins observes, " it is known that many of 

our most expert manipulators in experiments on natural philosophy, 
have failed in repeating those of Morichini and Mrs. Somerville. 
Hence we are led to infer, that the needles operated upon by Mori- 
chini and Mrs. Somerville, possessed magnetic properties previous 
to their being acted upon by the solar ray ; and that that magnetism 
escaped the notice of the experimenters when tested by them at the 
commencement of the operation." With the details of Morichi- 

ni's 



222 Geological Society, 

ni's experiments, we do not happen to be acquainted, nor do we 
know by whom they have been repeated in this country, except 
Mrs. Somerville. But we think the precision with which that lady 
has described her own researches, evinces, — even if it does not al- 
together preclude the idea that the needles &c. employed by her 
were previously devoid of magnetism, — that the more refrangible rays 
have a power of increasing, if not of imparting, magnetism ; and that 
white light does not possess, this power *. The fact of the increase 
of magnetism in steel by exposure to certain varieties of coloured 
light, is nearly as important with respect to the solar influence in 
the production or regulation of terrestrial magnetism, as that of 
its being induced by the same means would be, if certainly proved. 

[B.] 

XL. Proceedings of Learned Societies. 

GEOLOGICAL SOCIETY. 

May 16.— ~T)ECIMUS BURTON, Esq. of Spring Gardens j and 
U Major T. Perronet Thompson, of the 65th Regiment, 
were elected Fellows of this Society. 

The reading was begun of a Paper entitled, " On the Old Conglo- 
merates, and other secondary deposits on the north coasts of Scot- 
land j" by the Rev. Adam Sedgwick, Woodwardian Professor, Cam- 
bridge, V.P.G.S., &c. and R. I. Murchison, Esq. For. Sec. G.S. and 
F.R.S. 

June 6. — M. H. Ducrotay de Blainville. Member of the Institute 
of France, and of many other learned and scientific Societies, was 
elected a Foreign Member of this Society ; and Richard Taylor, Esq. 
Sec. L.S. of Middleton Square ; Charles Larkin Francis, Esq. of Nine 
Elms, Surrey ; and Jeffry Wyattville, Esq. R.A., of Lower Brook 
Street, — were elected Fellows of this Society. 

The reading of the Paper of Professor Sedgwick, and R. I. Murchi- 
son, Esq., begun at the last Meeting, was concluded. 

§ 1. Introduction. — The authors here give a brief sketch of the ge- 
neral structure of Scotland, to the north of the Forth and the Clyde. 
They consider the country to be composed of two entirely distinct 
classes of deposits — primary and secondary ; but with the primary de- 
posits are associated many mountain-masses of crystalline rock, which 
appear to have been protruded since the deposition of the newest of the 
secondary series ; and hence arises great, and sometimes insuperable, 
difficulty, in passing from one class of deposits to the other. The low- 
est of the secondary strata are chiefly composed of red-sandstone 
and red-conglomerate : and from a general review of this part of the 
subject, the authors conclude, that the conglomerate system on the 
N.E. coast of the Highlands is identical with that on the N.W. coast ; 
and that both the systems are of the same epoch with the great masses 
of conglomerate which commence at Stonehaven, and range along 
the southern flank of the Grampian chain % 

* See Phil. Trans, for 1826: or Phil. Mag. vol. Ixviii. p. 168. 

§ 2. Range 



Geological Society. 223 

§ 2. Range of the old-red-conglomerates through Caithness, and on 
the shores of the Murray Firth, #c. — These rocks are stated to appear 
in several unconnected masses on the north coast, between Cape 
Wrath and Port Skerry ; and from the latter place they range into 
the interior, and rise into a mountain -chain (the highest parts reach- 
ing the elevation of 3500 feet), which is continued to the granite of 
the Old of Caithness. Their range parallel to the shores of the Murray 
Firth, is also given with many details. They are slated to be deve- 
loped upon an enormous scale, and sometimes to form two distinct 
chains of broken mountains, resting unconformably upon the primary 
strata. On the south-eastern shores of the Murray Firth they gra- 
dually thin off j and finally disappear near Cullen bay, in Banfshrre. 

§ 3. On the general structure of Caithness. — After an account of 
the external appearance of the county, the authors describe in great 
detail two coast-sections. The first, commencing with the old con- 
glomerates of Port Skerry, which rest immediately upon the gra- 
nite, exhibits the successive deposits in ascending order, and termi- 
nates with the newer red-sandstone on the shores of the Pentland 
Firth. The second section exhibited on the east coast, commences 
with the newer red-sandstone, and passing through all the interme- 
diate deposits, finally exposes the old conglomerate system in a part 
of the coast between Borridale and the Ord. From a general review 
of the phenomena exhibited in these two sections, as well as from 
other details derived from the interior of the county, the authors 
conclude that the secondary deposits may be divided into three great 
natural groups : — 

1 . The old conglomerates, — which contain some subordinate masses 
of red-sandstone, red marie, and calcareo-siliceous flagstone ; and 
which, through the intervention of the red-sandstone, sometimes gra- 
duate into the next system. 

2. A great formation, occupying all the lower regions of the county, 
and composed of alternating beds of sandstone, siliceous and calcareo- 
siliceous schist and flagstone, dark foliated bituminous limestone, 
pyritous shale, &c. - } the siliceous beds giving the type to the lower 
part of the formation, and the calcareo-bituminous beds to the interme- 
diate part. This formation again becomes more siliceous and arena- 
ceous in the upper portion, and so appears to graduate into the next 
superior division. 

3. A great formation of red, brown, and variegated sandstone, which 
composes lofty precipices on the south shores of the Pentland Firth. 
It reappears on the other side of the Firth in the lofty red cliffs of the 
Orkneys, and there also reposes upon a calcareo-bituminous schist. 

§ 4. .Fossil fish of the secondary deposits of Caithness, #c. — These 
seem to be contained almost exclusively in the calcareo-bituminous 
schist, which is subordinate to the middle group of § 3. They do not 
appear to be confined to any particular part of it, but were found in 
various localities, some in the lowest and others in the highest part of 
the series ; and in many places scales and imperfect impressions ex- 
ist in the greatest abundance. Some imperfect specimens were ex- 
amined during a preceding year by the Baron Cuvier, who found that 

they 



224 Geological Society. 

they all exhibited a pointed tail (with the rays exclusively on the lower 
side, — as in the fish of the copper-slate of Thuringia), and notwith- 
standing the great imperfection of the specimens, he concluded that 
they were of the order Malacopterygii abdominales, and analogous to 
the bony pike. Since that time much more perfect specimens have 
been procured, which have been examined by Mr. Pentland j who has 
not only been enabled to confirm the conjectures of Baron Cuvier, 
but has ascertained two new genera, each containing two species. 
The first genus (Dipterus) has a double dorsal fin, and the other fins 
are nearly in the same position as in the Esocii. — One of the species 
{Dipterus macrolepidon) is remarkable for the size of its scales, which 
sometimes exceed half an inch in diameter. The second genus is 
nearly allied to Amia and Lepisosteus. The body is covered with 
hard quadrangular scales, disposed in oblique rows. In all the spe- 
cies the peculiar formation of the tail, before alluded-to, is the same. 

Along with the fish were found the remains of a Testudo, nearly al- 
lied to Trionyx, and one specimen of a vegetable impression : but not 
a single fossil shell or zoophyte has yet been discovered in any part 
of the county. It adds to the interest of this singular assemblage 
of organic remains, that they all resemble the inhabitants of fresh 
water. 

§ 5. Secondary deposits on the shores of the Murray Firth. — Several 
transverse sections through these deposits are described in great de- 
tail j and from a comparative view of the phenomena exhibited in a 
section from the conglomerate mountains in East Ross to the north 
Sutor of Cromarty, and from thence to Tarbet Ness, it appears that 
these secondary deposits admit of three natural divisions, like those 
described in Caithness. The conglomerates in both counties are the 
same. The formations in the lower region of East Ross contain sub- 
ordinate beds of calcareo-bituminous schist j and though fossils are 
much more rare than in Caithness, yet a few examples of fish-scales, 
and a fragment of a Testudo resembling a Trionyx, have been found 
between the north Sutor and Tarbet Ness. — Lastly, the highest beds 
of the whole series near Tarbet Ness, may be compared with the 
newer red-sandstone of the Pentland Firth. 

The transverse sections exhibited near the south shores of the Mur- 
ray Firth, differ considerably in their details from what has been de- 
scribed. The bituminous schists seem to be in some measure replaced 
by beds of concretionary limestone, resembling the cornstone of Here- 
fordshire : and these beds are surmounted by a great formation of 
white sandstone, nearly resembling the sandstone associated with the 
coal measures between the old and new-red-conglomerates in the Isle 
of Arran. 

§ 6. Red-sandstone and conglomerate series on the N.W. coast of Su- 
therland and Ross-shire. — These extend almost without interruption 
from Cape Wrath to Applecross ; and the authors (after stating a few 
facts in addition to the details already given by Dr. MacCulloch) as- 
sert that, through the intervention of the patches of conglomerate on 
the north coast of Scotland, they are most intimately connected with 
the conglomerates which extend from Port Skerry to the Ord of Caith- 
ness. 



Geological Society* 225 

ness. The two systems appear also to be identical in their general 
character and relations. There are some difficulties arising out of the 
peculiar modifications of the quartz-rock, which sometimes cannot be 
distinguished, mineralogically, from that of the unconformable red- 
sandstone and conglomerate series. The authors have, however, no 
hesitation in classing the great red-sandstone series, which extends 
from Applecross to Cape Wrath, with the older portions of the se- 
condary deposits of Caithness and Sutherland. 

§ 7. Conclusion.— The deposits previously described are here compared 
with the corresponding formations of England. — 1. The old-red-con- 
glomerates are, from their mineralogical character and position, iden- 
tified with the old-red-sandstone of English geologists. — 2. The great 
central deposit, containing the ichthyolites, does not appear to be 
perfectly identical with any formation hitherto described. It seems 
in some measure to occupy the place of the coal-formation. Many 
parts of it resemble grauwacke in mineralogical character j and from 
its enormous development, it can hardly be compared with the cop- 
per-slate of Germany. Again, none of the fish of Caithness are iden- 
tical with the fish of the copper-slate. The upper part of the Caith- 
ness schist might however, in accordance with the Arran section, be 
compared with the copper-slate ; in which case the red-sandstone of the 
Pentland Firth might be considered as the representative of the new- 
red-sandstone of England. There is however a break in the series, 
and it is perhaps impossible to determine where the interruption takes 
place.— 3. The red-sandstone on the shores of the Pentland Firth 
most nearly resembles the red-sandstone of Arran, which is interposed 
between the coal measures and the conglomerates of the new-red- 
sandstone. 

A paper was read by the Rev. Dr. Buckland, on the Cycadeoidea, 
a new family of fossil plants, specimens of which occur silicified in the 
Free-stone quarries of the Isle of Portland. 

These fossils have as yet been noticed only in the Isle of Portland ; 
their existence has long been known to many persons, and to the au- 
thor, who acknowledges the assistance of Mr. Brown and Mr. Lod- 
diges, in assigning to them their place in the vegetable kingdom, 
where they stand near the living Genera Zamia and Cycas. 

Their external form approaches to that of the fruit of a pine-apple, 
and is still more like the trunk of a living Zamia, varying from five to 
fifteen inches in height, and from eight to fifteen inches in width. The 
stems are nearly cylindrical, and terminate downwards in abroad flat 
bottom, without any indication of roots : they have no true bark, but 
are inclosed in a thick case, composed of the permanent bases of de- 
cayed leaves, having a structure like that of the bases of the leaves of 
the recent Zamia; they are terminated externally by lozenge-shaped 
impressions, or scars, of which a continuous series winds spirally, like 
the scales on a fir-cone, round the whole exterior of the plant. 

As yet no leaves have been found adherent to any of these fossils, 
but at the upper end there is a cavity, from which the crown and last 
leaves appear to have been removed, before the petrifaction of the 
stems. 

New Series. Vol. 4. No. 2 1 . Sept. 1 828. 2 G The 



226 Geological Society, 

The author describes and gives engravings of two species of these 
fossils, with comparative sections of the recent Zamia and Cycas. 

1. In the larger species, which he calls Cycadeoidea megahphylla, 
the bases of the leaves are two inches long, and have nearly the form 
and size of those of the Zamia horrida. The trunk is short, and has 
a deep central cavity, like the interior of a bird's nest,— in which a 
number of siliceous plates intersect one another, and form an irre- 
gular plexus, unlike any vegetable structure, but resembling the 
coarse cellular appearance that is common in fossil wood. Nearer 
the circumference there appear distinct organic radiations, disposed 
in an insulated circle, — like that in the trunk of a recent Zamia, but 
differing, in that it is much broader, and placed nearer the circumfer- 
ence of the stem. The larger plates of this circle are made up of 
smaller plates, almost invisible to the naked eye. Between this radi- 
ating circle and the outer case or leaf stalks, is a narrow band, com- 
posed of a minutely cellular, and nearly amorphous substance, but 
analogous in structure and position to a much broader band that is 
exterior to the radiating circle of the recent Zamia. 

2. In the second and smaller species {Cycadeoidea microphylla) , 
the bases of the leaves are about an inch in length, but small and 
numerous, much like those of the Xanthorrhceat or Gum Plant, of New 
South Wales. The trunk is more elongated, and the cavity at the 
summit less deep, whilst the transverse section exhibits the same irre- 
gular net-work at the centre, but near the circumference has two 
concentric circles composed of radiating plates ; and exterior to each 
of these a narrow ring devoid of plates, — analogous to the two lami- 
nated circles within two cellular circles in a recent Cycas. 

In external and internal structure, these plants approach more 
closely to the existing family of Cycadece than to any other ; and 
they supply, from the fossil world, a link to fill the distant void which 
separates the Cycadece from the nearest existing family, the Coniferce. 
Their occurrence in the Portland oolite adds another to the many 
facts which indicate the climate of these regions, during the period of 
the oolitic formations, to have been similar to that of our tropics. 

A letter to the President was read, from Gideon Mantell, Esq. 
F.G.S. &c. inclosing a list of the fossils of the county of Sussex. 

This list, which is taken principally from specimens in the author's 
own collection, enumerates the fossils, first, of the alluvial and dilu- 
vial deposits j and, successively, those of the London clay, the plas- 
tic clay, chalk, chalk-marle, firestone, gault, Shanklin sand, and Hast- 
ings deposits, including the Ashburnham beds. 

Subjoined is a comparative table j one of the most remarkable fea- 
tures of which, is the preponderance of the number of species in the 
marine formations over those of the beds assumed to be of fresh-water 
origin, in a ratio of not less than six to one ; the testaceous mollusca 
forming two-thirds of the whole, while in the fresh-water strata, the 
proportion is reversed. Thus the marine deposits contain upwards 
of two hundred and forty species of shells, and the two fresh-water 
formations but twenty-two species. In the other classes and orders, 
equally striking differences are observable. 

On 



Medico-Botanical Society. 227 

On the other hand the marine formations are destitute of the cha- 
racteristic fossils of the fresh-water formations, viz. birds, terrestrial 
and fresh-water reptiles, shells and vegetables. The author, in short, 
concludes that a comparison of the living inhabitants of our lakes and 
rivers, with those of the ocean, would not offer more striking discre- 
pancies. 

MEDICO-BOTANICAL SOCIETY. 

The last general meeting of the eighth session of this Society was 
holden on Friday, the 11th of Jul v, at its Apartments, 32 Sackville- 
street, Piccadilly; Sir James M'Gngor, M.D. F.R.S. K.C.T.S. Pre- 
sident, in the chair. 

The following gentlemen were elected to be Professors during 
the ensuingsession : Professor of Botany, John Frost, Esq., F.R.S. E. ; 
Professor of Toxicology, George Gabriel Sigmond, M.D .F.S.A. 
F.L.S. ; Professor of Materia Medica, John Whiting, M.D. 

A paper entitled " Remarks on the doubtful identity of Bonplan~ 
dia trifoliata, of Willdenow, and Humboldt and Bonpland, and the 
Angostura, or Carony bark tree," in a letter addressed by Dr. John 
Hancock to the President and Fellows of the Society, — was read. 

Dr. Hancock, who, during the year 1816, resided for several 
months in the districts in which grows the plant yielding the bark 
known in pharmaceutic language by the name of Cortex Angostura 
vel Cusparia?, on directing his attention to this subject, discovered 
several material discrepancies between the tree he observed, and the 
description of a tree said to produce the drug, and of which Baron 
Alexander Humboldt, in other respects such an accurate observer, 
sent specimens obtained from Carony to Professor Willdenow, of 
Berlin ; who, though there already existed a genus of that name, 
called it Bonplandia, in honour of Baron Humboldt's companion. 
This name was subsequently adopted by Humboldt and Bonpland 
in their splendid work on ^Equinoctial plants, though the former 
had previously given it the appellation of Cuspariajebrifuga. The 
opinion formed by Dr. Hancock was confirmed, on being informed 
by a gentleman of the name of Don Jose Tereas, with whom the 
travellers above-mentioned lodged, that they did not visit the mis- 
sions of Carony, but sent down an Indian, who returned with a sam- 
ple of the leaves of the tree in question, but, much to their disap- 
pointment, without flowers. The generic character having also 
become very doubtful to Dr. Hancock, he carefully examined its 
congeners, and found it agree in so many points with the genus 
Galipea of Aublet, that he considered it to be a species thereof, and 
in this opinion he has lately been confirmed by the arrangement of 
Professor DeCandolle, who has classed the Cusparia Jebrifuga, 
which, no doubt, is nearly allied to Dr. Hancock's plant, under the 
head Galipea. The paper then gave a detailed description of its 
botanical characters; which, with a figure of the plant, and a notice 
of its great efficacy in several diseases, especially in the malignant 
fevers, dysenteries, and dropsies prevalent in Angostura, in 1816 
and 1817, will be published in the next Number of the Society \ 

2 G 2 Transactions ; 



22S Intelligence and Miscellaneous Articles, 



•o 



Transactions ; together with a comparative statement of the differ- 
ences existing between Bonplandia trifoliata (Willd.), vel Cusparia 
Jebrifiiga (Humb. and DeC), vel Galipea Cusparia (DeC), and the 
real Angostura-bark tree ; the most striking of which is, that instead 
of being a large and majestic forest tree, as described in The Plantcz 
JEquinoctiales Orbis Novi, the authors of which, no doubt, thought 
the tree found by them in the neighbourhood of Santa Fe de Cu- 
mana and Nueva Barcelona, was the same as that of which they ob- 
tained leaves in Angostura ; — it is a tree, or almost shrub, of not 
more than from twelve to fifteen, and at the most twenty feet, in 
height, and four or five inches in diameter. The Doctor concludes 
by proposing that the plant described by him should be named 
Galipea officinalis. 

The paper was accompanied by fine native specimens of the bark, 
leaves, flowers, capsules, and seeds of the plant. The thanks of 
the Meeting were ordered to Dr. Hancock for this very interesting 
communication. 



XLI. Intelligence and Miscellaneous Articles, 

TUBES FORMED BY LIGHTNING. 

SOME very long tubes, supposed to be formed by the action 
of lightning, having lately been presented to the Academy 
of Sciences by Dr. Fiedler ; MM. Hachette, Savart and Beudant, 
attempted to form similar tubes by the action of the electrical ma- 
chine. The battery was discharged through powdered glass placed 
in a hole made in a brick: tubes were obtained perfectly similar to 
those which occur in nature, and which are attributed to lightning, 
except that they are of dimensions proportional to the means em- 
ployed in forming them. 

In one experiment made upon powdered glass, a tube of about 
twenty-five millim. in length was obtained ; its external diameter, 
which decreased irregularly from one extremity to the other, is from 
three millim. to one millim. and a half, and the interior diameter 
half a millim. 

In another experiment, powdered glass was mixed with common 
salt, and a tube of thirty millim. in length was formed, equally regu- 
lar both within and without. The mean external diameter is four 
millim. and a half, and the internal diameter two millim. Two other 
experiments yielded smaller and less perfect tubes. Experiments 
made with powdered felspar and quartz did not succeed. It is re- 
marked that the artificial as well as the natural tubes have a brown- 
ish layer on the interior ; a circumstance which the authors of the 
experiments find it difficult to explain, unless it depends upon the 
oxidation of a small quantity of iron. — Ann. de Chim. March 1828. 



ARTIFICIAL ULTRAMARINE. 

M. Guimet, of Toulouse, has succeeded in forming this fine 
colour: it appears that M, Gmelin ha3 also discovered a pro- 
cess 



Intelligence and Miscellaneous Articles. 229 

cess for forming it, and which is given as follows in the An- 
nates de Chimie for April last. In giving it, it is to be ob- 
served that M. Guimet expresses a doubt whether it will yield the 
colour at a sufficiently cheap rate; but M. Gmelin asserts that 
it succeeds infallibly : — Prepare hydrate of silica and hydrate of 
alumina; the former is obtained by fusing well-powdered quartz 
with four times its weight of carbonate of potash, dissolving the 
fused mass in water, and precipitating by muriatic acid; hydrate 
of alumina is procured by precipitating a solution of alum with am- 
monia. These two earths are to be carefully washed with distilled 
water. After this, the quantity of dry earth remaining is to be as- 
certained, by heating to redness a certain quantity of the moist 
precipitates. The hydrate of silica which 1 employed in my expe- 
riments, contained in 100 parts 56, and the hydrate of alumina 3*24 
parts of anhydrous earth. 

Dissolve afterwards, with the assistance of heat, as much of this 
hydrate of silica as a solution of caustic soda is capable of taking 
up, and determine the quantity dissolved. Take then for 72 parts 
of the latter (anhydrous silica), a quantity of hydrate of alumina, 
which contains 70 of anhydrous alumina; it is to be added to the so- 
lution of silica, and the mixture is to be evaporated, with constant 
stirring, until a moist powder only remains. 

This combination of silica, alumina and soda, is the base of the 
ultramarine, which is to be coloured by sulphuret of sodium ; and 
this is effected in the following manner : — Put into a Hessian cruci- 
ble, provided with a good cover, a mixture of two parts of sulphur, 
and one part of anhydrous carbonate of soda ; it is to be gradually 
heated, until at a moderate red heat the mass is well-fused : this 
mixture is then to be projected, in very small quantities at a time, 
into the middle of the fused mass; as soon as the effervescence, oc- 
casioned by the vapour of water, ceases, a fresh portion is to be 
thrown in. Having kept the crucible moderately red-hot for an 
hour, it is to be taken from the fire and suffered to cool. — It now 
contains ultramarine, mixed with sulphuret in excess, which is to 
be separated by water. If there be sulphur in excess, it is to be 
expelled by a moderate heat. If the whole of the ultramarine be 
not equally coloured, the finer parts may be separated, after having 
reduced them to a very fine powder, by washing with water. — Ibid. 
April 1828. 

MELLITIC ACID. 

M. Woehler makes the following statement as to the means of 
obtaining this acid. I boil the mellite (mellitate of alumina) re- 
duced to fine powder with subcarbonate of ammonia, and crystallize 
the resulting mellitate of ammonia. This salt is dissolved and pre- 
cipitated by acetate of lead, and the precipitate is decomposed by 
sulphuretted hydrogen. Filter and evaporate to the consistence of 
a syrup ; crystallization occurs with difficulty, but a white mass is 
obtained. This is to be dissolved in cold alcohol, and the solution 
by spontaneous evaporation, yields groups of stelliform crystals ; 
these crystals have a strong acid taste, are unalterable in the air, 

and 



230 Intelligence and Miscellaneous Articles. 

and dissolve readily in water and alcohol. This acid may be sub- 
jected to a high temperature without being decomposed ; it does not 
fuse, but is eventually converted into another acid, which is volati- 
lized, and a coaly residuum. No empyreumatic oil is formed, nor 
does it even give any smell of burning. Neither sulphuric nor ni- 
tric acid acts upon this acid. The substance which Vauquelin sup- 
posed to be pure acid, was supermellitate of potash. — Hensman's 
Repertoire de Ckimie, Feb. 1828. 

■ ■ 

ACTION OF ACIDS ON PALLADIUM. BY M. FISCHER OF BRESLAU. 

It is well known that palladium is dissolved by cold nitric acid, 
without the evolution of either nitrous gas or subnitrous acid. This 
is also the case with mercury, which dissolves in cold colourless 
concentrated nitric acid. Cold sulphuric acid does not act upon 
palladium ; with the assistance of heat, the acid dissolves it with the 
evolution of sulphurous acid : the solution is of a reddish yellow, 
and when it is saturated, it deposits a red powder on cooling ; this 
powder is the neutral sulphate ; it is readily soluble in water, to 
which it imparts a yellow colour. On the undissolved palladium 
there remains another powder, which is of a deeper colour ; this is 
slightly soluble in water, and is the subsulphate. Cold muriatic 
acid dissolves palladium, and without the evolution of hydrogen. 
There is no doubt but that the oxidation of the metal is effected by 
the oxygen of the air ; it does not occur with hot muriatic acid, 
which is sufficient to prove, that it cannot be derived from any other 
cause : the vapour which the heat raises preserves the fluid from 
the contact of the air, and prevents the metal from being oxidized. 
It is not quite impossible that the solution of the metal in the acid 
may be effected by the double affinity of the chlorine for the metal, 
and the hydrogen for the oxygen of the air. More than one extra- 
ordinary result, which it is not easy to credit, is effected by this 
double action ; and among others the oxidation of iron by water, the 
bleaching of linen on meadows, and the dehydrogenation of water 
by the leaves of plants in the sunshine, are similar phenomena. I 
had previously observed the solubility of silver in the same acid, 
owing to a similar cause : the solution of both these metals, neces- 
sarily occurs but slowly; it is however sufficiently rapid to be render- 
ed apparent by reagents within twenty-four hours. With respect to 
the solution of silver, it is sufficient to add water to it to precipitate 
the luna cornea. Muriatic acid therefore dissolves metals which 
cannot separate the chlorine, and which cannot therefore be the 
medium through which the decomposition of water is effected. Mu- 
riatic acid, as I have satisfied myself by experiment, dissolves in 
the same manner, and at common temperatures, almost all other 
metals. Platinum itself saturates aqua regia, upon which it acts in 
the contact of the air when cold, but the operation goes on very 
slowly. I ought to mention that in this last experiment I employ 
a very weak acid. 

Phosphoric acid, assisted by long boiling, oxidizes and dissolves 
palladium, but on cooling, the phosphorous acid which is formed, 

decomposes 



Intelligence and Miscellaneous Articles. 231 

decomposes the salt and reduces the oxide, the metal of which floats 
on the fluid in the form of a brilliant metallic pellicle. 

The solutions of palladium, whether in nitric or in muriatic acid, 
or in aqua regia, require only a slight excess of acid to possess rather 
a yellowish brown colour, than a reddish one, with a styptic and 
metallic taste ; they mix with water in all proportions without be- 
coming turbid; when neutral, or with only a slight excess of acid, 
they are decomposed by water into sub- and super-salts. — Ibid. 

PREPARATION OF CONTA, THE ALKALI OF THE CONIUM MACU- 
LATUM. BY M. BRANDES. 

The best method of obtaining this alkali is to digest the fresh 
herb in alcohol during some days, afterwards evaporating the fil- 
tered alcohol, agitating the residuum with water, and treating this 
mixture either with alumina, magnesia, or oxide of lead ; the whole 
is to be evaporated to dryness, and the residuum obtained treated 
with a mixture of alcohol and aether, which, when again evaporated, 
leaves the conia. This substance, which was discovered and also 
named by M. Peschier, possesses very marked alkaline properties. 
According to M. Giseke, the aqueous solution forms, with the tinc- 
ture of iodine, an abundant reddish precipitate ; it renders tincture 
of galls slightly brown, precipitates muriate of zinc and nitrate of 
mercury of a dirty yellow ; renders carbonate of potash and soda 
slightly turbid ; gives a brown colour to muriate of platina ; and pro- 
duces a white precipitate with the nitrates of silver and barytes, the 
acetates of barytes and lead, muriate of lime and lime-water, 

Haifa grain of conia is sufficient to kill a rabbit j the symptoms 
which occur resemble those produced by strychnia. — Ibid. 



ON PYROPHORUS. 

M. Gay-Lussac, in forming this substance, used calcined lamp- 
black instead of honey or flour, usually employed. Potash-alum 
heated with this form of carbon, gave at first carbonic acid and sul- 
phurous gas, and nearly in equal volumes ; afterwards carbonic acid 
was obtained nearly pure, and at last it was mixed with oxide of 
carbon, and this eventually prevailed. The pyrophorus so formed 
burnt readily. M. Gay-Lussac is of opinion that carbon is not ne- 
cessary to the combustion : he made a mixture of nearly 75 parts 
of alum, and 3-33 of lamp-black, or 1 atom of the former and 3*5 
atoms of the latter ; and this mixture, when calcined, at nearly a 
white heat, gave a reddish-brown product, containing no traces of 
carbon, but it burnt very readily, and left a grayish-white residuum. 
Alum is not essential to the preparation. Sulphate of magnesia 
produces the same effect ; sulphuret of potassium alone does not, 
however, inflame spontaneously in mass ; and it occurred to M. 
Gay-Lussac, that alumina or magnesia acted merely by dividing the 
sulphuret ; that this was the case was proved by substituting char- 
coal for them, and though the compound obtained, by using 27*3 of 
sulphate of potash, or 1 atom and 7 5 of lamp-black, or 4 atoms 

agglutinated 



232 Intelligence and Miscellaneous Articles* 



agglutinated and did not inflame; yet, on using double the quantity 
of lamp-black, the pyrophorus obtained was extremely pulveru- 
lent, and was astonishingly inflammable, so much so as to be almost 
dangerous. 

This pyrophorus yields no sulphurous acid during combustion ; 
when put into water, it gives no hydrogen, showing that there is no 
uncombined potassium ; and when the solution is treated with an 
acid, sulphuretted hydrogen is evolved, and sulphur precipitated. 
Unlike common pyrophorus, it does not require moist air for its 
combustion : the charcoal does not appear to be in a state of com- 
bination, for the aqueous solution of the pyrophorus is not distin- 
guishable from that of sulphuret of potassium, made without charcoal; 
and this latter substance is so readily deposited in the vessel, as not 
to indicate that state of minute division which is characteristic of 
previous combination. 

The new pyrophorus, compared with the common, appears to 
owe its greater inflammability to several causes : to its more mi- 
nutely divided state, the absence of inactive earthy matter, and also 
to the smaller proportion of sulphur. Sulphate of soda, used in 
equivalent proportion, produces nearly the same effect as sulphate 
of potash ; but sulphate of barytes did not at all answer. M. Gay- 
Lusaac is of opinion that the action of potassium depends essen- 
tially upon the great combustibility of sulphuret of potassium, and 
its action upon water and air : alumina and magnesia appear only 
to divide the combustible matter; but charcoal being itself com- 
bustible, is not passive in the phenomena ; the combustion having 
once commenced, it supports it. A very high temperature did not 
appear to alter the inflammability of the pyrophorus, provided that, 
during the cooling, the air was carefully excluded. — Ann. de Chim. 
April 1828. 

Note. — Although we are by no means disposed to undervalue the 
facts contained in the above statement, yet it will appear from the 
following quotation from Dr. Thomson's System of Chemistry, vol. 
ii. p. 541, that one of the principal of them does not possess all the 
novelty which the author appears to suppose belongs to it. " Scheele 
proved that alum deprived of potash is incapable of forming pyro- 
phorus, and that sulphate of potash may be substituted for alum." 

R. P. 

EFFECT OF EBULLITION UPON CUPREOUS SALTS. 

It has been stated by Celin and Taillifert, that when blue or green 
carbonate of copper is boiled in water, it retains its carbonic acid, 
although it becomes black and anhydrous. On repeating these 
experiments, M. Gay-Lussac found that the black powder is mere 
anhydrous oxide of copper, and does not retain any carbonic acid. If 
the boiling be stopped as soon as the carbonate becomes black, then 
the product effervesces on the addition of acids ; this is derived from 
the presence of some remaining carbonic acid. Acetate of copper 
suffers similar decomposition by the same process. 

BORURET 



Intelligence and Miscellaneous Articles* 233 

BORURET OF IRON. 

M. Lassaigne gives the following directions for preparing this com- 
pound : — Prepare a sub-borate of iron by precipitating persulphate 
of iron by borax j wash and dry the precipitate, form it into a paste 
with water, and mould it into a small cylinder - } when dry, place this 
cylinder within a porcelain-tube, heat it red-hot, and pass pure dry 
hydrogen over it. Boruret of iron is formed ; it acts slightly upon 
the magnetic needle, and consists of 77*43 of iron, and 22 57 of 
boron, or of one atom of each nearly. — Institution Journal, July 1828. 



VARIETIES OF BORAX. 

M. Payen gives the following as the results of his analysis of cry- 
stallized boracic acid, anhydrous, prismatic, and octohedral borax,— 
oxygen being 10. 

Crystallized Boracic Acid. 

One atom acid 44 

Three atoms water . . . 3373 



7773 

Anhydrous Borax. Prismatic Borax. Octohedral Borax. 
Boracic acid 2 atoms . . 88 2 atoms . . 88 2 atoms . . 88 

Soda 1 atom . . 3909 1 atom . . 39*09 1 atom . . 39*09 

Water 10 atoms . 11243 5 atoms . . 56-217 



127*09 239*52 183*307 
Ibid. 

FIGURE OF THE CELLS OF THE HONEYCOMB. 

We are indebted to our correspondent M. Fayolle, for directing 
our attention to a paper on this subject by the celebrated Maclaurin, 
in the Philosophical Transactions for 1 743. It appears from the no- 
tice which M. Fayolle has communicated to us, that Fontanelle, the 
Secretary of the Academie des Sciences, in concluding the account of 
Kcenig's paper read before that learned body in 1739, as mentioned 
by Mr. Sharpe in his paper on the subject, at p. 20 of our present vo- 
lume, makes the following remark : — " La grande merveille est que 
la determination de ces angles passe de beaucoup les forces de la ge6- 
m£trie commune, et n'appartient qu'aux nouvelles methodes fondees 
sur la theorie de l'infini." 

Maclaurin observes in the memoir in question, " Mr. de Reaumur 
has informed us (Mem. sur les Insectes, torn, v.), that Mr. Koenig 
having, at his desire, sought what should be the quantity to be given 
to this angle, in order to employ the least wax possible in a cell of 
the same capacity ; that gentleman had found, by a higher geometry 
than was known to the ancients, by the method of inftnitesmals, that 
the angle in question ought in this case to be of 109° 26'. And we 
shall now make it appear, from the principles of common geometry, 
that the most advantageous angle for these rhombuses is indeed, on 
that account also, the same which results from the supposed equality 
of the three plane angles that form the above-mentioned solid ones." 
He then proceeds to demonstrate, by a method purely geometrical. 

New Series. Vol. 4. No 21. Sept. 1828. 2 H that 



234« Intelligence and Miscellaneous Articles. 

that " the angle of the rhombus of the best form is that of 109° 28' 
16" ;" precisely the result obtained by Mr. Sharpe by the use of the 
fluctional theorem de maximis et minimis. 



MR. BUCHANS EXPERIMENTS ON THE AMALGAMATION OF SIL- 
VER-ORES. 

Some very interesting experiments have lately been made upon 
the process of amalgamating the ores of silver in Mexico, by Mr. 
Buchan, at the Haciendas of Real del Monte. Considerable ob- 
scurity has prevailed as to the mode in which the decomposition of 
the various substances is brought about, and the silver detached 
from its combination with sulphur, so as to be in a state to be acted 
upon by the quicksilver. 

Descriptions of the mode of conducting the operations of amal- 
gamating in Mexico, will be found in the works of Humboldt ; in 
the Selections relating to Mexico, by Taylor ; and in Capt. Lyon's 
Journal. 

The ores are mingled at first with a mixture of muriate of soda, 
calcined copper, and iron pyrites, called magistral; the mass in a 
short time heats, and decomposition goes on ; after which, quick- 
silver is incorporated with it. If the heat generated be greater 
than experience has shown to be favourable to the proper effect, 
it is checked by the addition of lime. 

The use of the magistral has not been hitherto clearly explained : 
from the mode in which it is prepared, it may be supposed to con- 
sist, as Humboldt states, of the sulphates of iron and copper ; and 
the property of heating the mass has been attributed to these salts. 

Mr. Buchan has found that the magistral contains a certain quan- 
tity of free sulphuric acid, and that it is esteemed good very much 
in proportion to this quantity. He has also exposed ores to amal- 
gamation, substituting dilute acid for the magistral ; and the effect, 
as far as the process had been conducted, was similar to that pro- 
duced by the usual mode. 

It is possible that the oxides in the magistral, particularly that of 
iron, may have important uses in the later stages of the operation j 
but as the magistral, in some of the mining districts in Mexico, is 
obtained at great expense only, it is probable that its use may be su- 
perseded with advantage, when further experiments have been made ; 
and, at any rate, the researches of Mr. Buchan will probably throw 
much light on this obscure subject, which may lead to important 
results. 

ACCOUNT OF A CHEAP AND EASILY- CONSTRUCTED BAROMETER 
FOR MEASURING ALTITUDES, &C BY MR. J. OTLEY. 

To the Editors of the Philosophical Magazine and Annals. 
Gentlemen, 
Observing in a late Number of the Philosophical Magazine*, a pro- 
posal by Mr. Nixon for determining the heights and dip of strata 
by barometric observations, I take the liberty of offering a descrip- 
tion of an instrument I have lately constructed, whic£, I think, par- 

* See Phil. Mag. and Annals, N. S. vol. iii. p. 11 

ticularly 



Intelligence and Miscellaneous Articles. 235 

ticularly applicable to that purpose, as well as to the measurement 
of any elevation where a barometer can be employed. 

I procured a straight barometer-tube thirty-three inches in length, 
and also a bottle one inch in diameter, and the same in depth. In 
one side of this bottle, near the top, I bored a small hole ; and hav- 
ing filled the tube with mercury, and the bottle rather more than 
half full, I inserted and cemented the tube into the neck of the bot- 
tle, with its open end a little below the middle ; so that in every po- 
sition the opening was covered with mercury. 

I then fitted the whole into a casing of wood, the tube, for twenty- 
five inches of its length, being imbedded level with the surface ; the 
upper end opposite the scale, for the length of eight inches, being 
fully exposed. The divisions of the scale denoting inches and 
tenths, are reduced a little, to compensate for the variation of the 
surface of the mercury in the cistern. For a vernier, I took a very 
thin piece of silver, the length of eleven divisions of the scale, and 
breadth something more than half the circumference of the tube ; 
this divided into ten parts by lines quite across, except a small 
space for the figures, and bent so as to embrace the tube with a 
gentle elastic pressure, is made to slide as freely as required : the 
lines of the scale being reflected from the surface of the silver, af- 
ford great assistance in observing the coincidence, dividing the inch 
very accurately into an hundred parts ; and a figure in the third 
place of decimals may be estimated by the eye. The lower part of 
the case being secured by a piece of thin brass plate, with a bottom 
projecting in front beyond the diameter of the bottle, I fit a wooden 
cover, the whole length of the instrument, with two pins to pass 
into corresponding holes in the bottom-plate : a bit of soft leather is 
placed so as to press on the mouth of the hole in the bottle, and 
the case being made a little taper, is easily kept close by a slight 
hoop of leather. 

This barometer, with a moderate degree of precaution, is suffici- 
ently portable, and very ready in use ; it requires no other prepa- 
ration for an observation than merely to hang it perpendicularly, and 
take off the cover ; the air having immediate access to the surface 
of the mercury in the cistern, renders it more satisfactory than those 
in which it has to pass through the pores of the wood, and where 
the surface of the mercury cannot be seen ; and less troublesome 
in use, with less risk of error, than others, in which it has to be ad- 
justed by a screw for every observation. 

If a due proportion is attained in the divisions of the scale, and 
proper attention paid in taking a mean observation at each station, 
to obviate the effects of the friction unavoidable in small tubes, I 
am convinced that it will be found as accurate as any barometer of 
the same dimensions, although of a far more elaborate and expen- 
sive construction. 

Keswick, Aug. 7th, 1828. I am, &c. J. Otley. 



NUMMULITES IN THE GREEN-SAND FORMATION. 

In a note inserted in the third volume of the Memoires dc la 

2 H 2 Societe 



236 Intelligence and Miscellaneous Articles. 



'& 



Societe LinnSenne de Normandie, M. Elie de Beaumont, describing 
the environs of Martigues (Bouches du Rhone), mentions the oc- 
currence of nummulites, in rocks which he refers to the green-sand 
formation, and states that the same strata contain, besides Hippu- 
rites, gryphites, terebratulae, &c. the Cucullea carinata, a fossil 
whose analogue also is found in the ferruginous and green-sands of 
Saint-Ils, near Castellane ( Basses Alpes), the barns of Bellevue, 
near Uchaux (Vaucluse), at Brousseval, near Vassy (Haute Marne), 
and at the mountain of St. Catharine, near Rouen : they also con- 
tain a trochus, or Pleurotoma, and a Melania, or Phasianella, whose 
analogues exist in the green-sand of England and Normandy. Fol- 
lowing up these strata, he found at Gignac, gryphites, Cucullea?, 
and Spatangus, known to belong to the green-sand ; and near Pen- 
nes, on the road to Marseille, Milliolites, Spatangus, Cucullea, Tri- 
gonia, Pecten (Pecten quinque-costatus), equally known to belong 
to the green-sand. 

Mr. De la Beche, in a late examination of the environs of Nice 
and of the neighbouring coast, also found an abundance of nummu- 
lites in rocks which he refers to the green-sand ; in this case they 
are sometimes mixed in the same beds with gryphites, and consti- 
tute a subordinate portion of a formation in which are discovered 
Ostrea carinata, turrilites, inoceramus, ammonites, nautili, terebra- 
tula, dolium, echinites, &c. 

This nummulitic green-sand, which cannot be referred to any 
member of the tertiary series, the calcaire grossier for instance, 
though this latter contains both nummulites and green grains, is a 
rock very extensively distributed over the Alps j of the calcareous 
portion of which it constitutes a considerable part, forming the 
summits of many lofty mountains. 

FOSSIL HERBIVOROUS REPTILES. 

In a late communication from Dr. Jseger ofStutgard, to Mr.Mantell 
of kewes, the learned Professor states that he has discovered in the 
Keuper-sandstein the remains of two species, if not genera, of herbi- 
vorous reptiles : the one having lateral teeth of a cylindrical, and 
the other of a cubical form ; the latter possessing lateral eminences 
somewhat similar to the teeth of the Iguanodon. Dr. J. expresses his 
intention of publishing figures and descriptions of these interesting 
remains in the course of the year. 



SOLAR SPOTS. 

The two large solar spots described in the last Number of the Phil. 
Mag. and Annals, came on the sun's eastern limb again between the 
hours of 7 and 10 a.m. on the 10th of July, with the same contracted 
and linear appearance as when they went off early in the morning of 
the 26th of June. At sunset on the 10th of July, they were a little 
more defined, and somewhat enlarged in the central part of the 
black lines which formed their nuclei, but no umbra yet appeared 
round either of them. At noon of the 12th, the nuclei and umbrae 
of these spots were elliptical. In the evening of the 16th, the up- 
per- 



New Patents. 237 

per spot showed its nearest position to the sun's centre, with very 
nearly the same solar latitude as before given, and was quite circu- 
lar, but not so large as it was last month by one-third of its diame- 
ter. At this time the lower spot had become irregular in shape, 
and was divided into two in one umbra; on the 18th into three, 
and on the 1 9th into four distinct spots in the same umbra, with 
little variation in its shape or size, but which on the 21st had be- 
come more faint, and the small spots decreased. At noon of the 
22nd, the spots had approached near the sun's western limb in the 
usual contracted state, and at 7 p. m. they were, as nearly as could 
possibly be ascertained from a correct drawing, in the same posi- 
tion on the sun's disc as at noon on the 25th of June, making the 
time of their revolution 27 days and 7 hours. 

The spot which had divided went off in the morning of the 23rd, 
and the upper one slid behind the sun's western limb at 2 p. m. the 
same day, forming a little indentation thereon about a quarter of an 
hour. The upper spot, which has been on the sun's disc since the 
20th of May, is diminished in size, and growing faint ; and the lower 
one, which has been on more than forty days, is more faint; therefore 
it is doubtful whether they will last another revolution : but should 
they continue on so long, an opportunity may be afforded of ascer- 
taining the precise time of their revolution with still greater accu- 
racy, as it is only by repeated revolutions of the same spot or spots, 
that this circumstance can be correctly known, in consequence of 
the many difficulties and obstacles that generally occur in making 
observations of this sort. 

LIST OF NEW PATENTS. 

To A. Bernhardt of Finsbury-square, for his method of raising wa- 
ter. — Dated the 24th of July 1828.-— 6 months allowed to enrol spe- 
cification. 

To R. Wornum, of Wigmore-street, for improvements on upright 
piano-fortes. — 24th of July. — 2 months. 

To J. C. Daniell, of Lumphey Stoke, Wiltshire, for certain improve- 
ments applicable to the manufacturing and preparing of woollen 
cloth. — 5th of August. — 6 months. 

To J. L. Higgins, of Oxford-street, Esq. for his improvements on 
wheel carriages. — I lth of August. — 6 months. 

To W. Mencke, of Park Place, Peckham, Surrey, for his improve- 
ments in preparing materials for, and in the making, bricks.— 11th 
of August. — 6 months. 

To L. R. Fitzmaurice, of Jamaica Place, Commercial Road, Mid- 
dlesex, for his improvements on ship- and other pumps. — 1 lth of Au- 
gust. — 6 months. 

To W. Grisenthwaite, of Nottingham, Esq., for a new process for 
making sulphate of magnesia, common called Epsom Salts. — 1 lth of 
August. — 6 months. 

To H. Maxwell, of Pall -Mall, for an improvement in spring spur- 
sockets. — 13th of August. — 2 months. 

To T. Stirling, of the Commercial Road, Lambeth, for improve- 
ments on filtering apparatus. — 16th of August.-— 6 months. 

To 



238 Meteorological Observations for July 1828. 

To B. M. Payne, of the Strand, scale-maker, for improvements on 
weighing-machines. — 18th of August.— 6 months. 

To E. Barnard, of Nailsworth, near Minchinhampton, Gloucester, 
for improvements in weaving and preparing cloth. — 19th of August. 
— 6 months. 

To P. Foxwell, W. Clark, and B. Clark, all of Dye House Mill, 
Minchinhampton, Gloucester, for improvements in machinery for 

shearing and finishing woollen and other cloths. — 19th of August 

6 months. 

To W. Sharp, of Manchester, for improvements in machines for 
spinning or roving of cloth, silk, wool, &c— 19th of August. — 
months. 



METEOROLOGICAL OBSERVATIONS FOR JULY 1828. 

Gosport. — Numerical Results for the Month. 
Barom. Max. 30-03 July 31. Wind W.— Min. 29-24 July 20. Wind S.E. 
Range of the index 0-79. 

Mean barometrical pressure for the month 29«7H 

Spaces described by the rising and falling of the mercury 4-220 

Greatest variation in 24 hours 0-430. — Number of changes 30. 
Therm. Max. 82° July 3. Wind S.W.— Min. 47° July 29. Wind N.W. 
Range 35°.— Mean temp. of exter. air 65°-55. For 31 days with © in <& 66*37 
Max. var. in 24 hours 25°-00 — Mean temp, of spring water at 8 A.M. 54°-15 

De Luc's Whalebone Hygrometer. 

Greatest humidity of the air in the evening of the 21st 92° 

Greatest dryness of the air in the afternoon of the 29th 41 

Range of the index 51 

Mean at 2 P.M. 53°-5 —Mean at 8 A.M. 61°-1— Mean at 8 P.M. 67-2 

of three observations each day at 8, 2, and 8 o'clock 60-6 

Evaporation for the month 3-70 inches. 
Rain near ground 3-405 inches. 
Prevailing wind, S.W. 

Summary of the Weather. 
A clear sky, 2§ ; fine, with various modifications of clouds, 15 j an over- 
cast sky without rain, 8£ ; rain, 5. — Total 31 days. 
Clouds. 
Cirrus. Cirrocumulus. Cirrostratus. Stratus. Cumulus. Cumulostr. Nimbus 
26 17 30 27 27 26 

Scale of the prevailing Winds. 
N. N.E. E. S.E. S. S.W. W. N.W. Days. 
2 £ 4 2i 12 5 5 31 

General Observations. — This month has presented a series of showery 
and windy weather, which was often attended with lightning and thunder; 
but it was very fine at intervals, and favourable to the growing corn, fruits, 
and gra3s-lands. In the North of England the rain has often been very 
heavy. 

The wheat in this neighbourhood formed into ears the first week in 
June, and the harvest commenced the last week in July. It is generally 
short in ear, but thick and clean, and likely to produce average crops, not- 
withstanding the winter floods and a cold spring. The barley and oats 
have a promising appearance for larger crops, and will soon be fit to cut. 

At 



Meteorological Observations for July 1828. 239 

At half-past 8 o'clock in the evening of the 3rd instant, the clouds as- 
sumed a black electrical aspect, and the lightning and thunder gradually 
came on as they united by means of crossing currents of wind from S.W. 
by W. and S.E. From that time till sunrise the following morning, when 
the S.E. wind ceased to blow, the lightning was almost incessant, the 
flashes frequently amounting to 12 or 15 in a minute, and the streams of 
electric fluid presented themselves in almost every geometrical form, ac- 
companied with light showers of rain at intervals. So much lightning 
from the passing clouds has not been observed here at any time since the 
night of the 28th of July 1814, when it was nearly similar in appearance 
for the same space of time. In the nights of the 7th and 8th we had vivid 
sheet lightning, and lightning and thunder in the afternoon of the 14th, 
which were produced by means of two winds crossing at right angles, and 
the consequent inosculation of the clouds. From the 26th of June to the 
18th of July, the summer cockchafers were very numerous during the even- 
ing twilight : and for two or three years past a great number of the species 
of the Melolontha solstitialis has also appeared in the evenings of June and 
July, and are considerably smaller than those that generally come in May. 

The mean temperature of the external air this month is about one degree 
and a half higher than the mean of July for the last twelve years. 

The atmospheric and meteoric phenomena that have come within our 
observations this month, are one lunar and nine solar halos, one meteor, 
one rainbow, lightning and thunder on three different days; and eight 
gales of wind, namely, one from the South-east, two from the South-west, 
three from the West, and two from the North-west. 



REMARKS. 

London. — July 1. Very fine. 2. Overcast in morning; .fine, 3. Very 
fine ; sultry with heavy thunder storm at night. 4. Cloudy and warm. 

5. Very fine. 6. Cloudy with showers. 7. Fine. 8. Sultry with thunder, 
and slight rain at night. 9. Showery: heavy rain at night. 10. Showery 
morning: fine. 11. Cloudy. 1 2. Heavy rain. IS. Showery. 14. Sultry 
with much thunder. 15. Showery. 16, 17. Fine. 18, 19. Showery. 
20. Rainy, with thunder. .21. Fine morning: rain at night. 22. Showery. 
23. Showery, with thunder. 24. Cloudy, with showers. 25. Fine morn- 
ing : showery. 26. Cloudy, with showers. 27. Showery. 28. Very fine. 
29. Showery. 30. Fine. 31. Very fine. 

Boston. — July 1 — 4. Cloudy. 5 — 7. Fine. 8, 9. Rain. 10. Stormy. 
1 J . Fine. 12. Rain. 1 3. Stormy and rain. 14. Fine : rain a.m. and p.m. 

15. Rain. 16. Cloudy. 17. Rain. 18. Cloudy: thunder and lightning, 
with rain p.m. 19. Cloudy. 20. Cloudy : rain p.m. 21. Cloudy. 22 — 24. 
Fine. 25. Rain : heavy rain. 26. Cloudy. 27. Rain. 28. Fine : rain at 
night. 29. Fine : thunder, hail, and rain, p.m. 30. Rain. 31. Cloudy. 

" The quantity of rain fallen in the last month exceeds that of any other 
month from the commencement of my observations in August 1823, by 
three inches and eighty-four hundredths.' The greatest fall of rain, except 
as above, that I ever noticed was in September 1826. The rain-gauge in 
that month indicated a fall of 4*18.— The average height of the Barometer 
is only 29-15."— S. V. 

Penzance.— July 1 . Fair : rain. 2. Fair : showers. S. Rain. 4, 5. Fair. 

6. Clear. 7. Fair: rain. 8. Fair. 9. Rain: fair. 10. Fair. 11. Fair: 
rain. 12. Clear. 13. Clear: showers. 1 4. Fair : showers. 15. Showers. 

16. Fair : showers. 17. Fair: rain. 1 8. Fair : showers. 19, 20. Clear: 
showers. 21. Fair: showers. 22. Fair. 23. Misty rain. 24. Rain. 
25, 26. Fair: showers. 27. Fair: clear. 28 — 30. Clear. 31. Fair. 

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THE 

PHILOSOPHICAL MAGAZINE 

AND 

ANNALS OF PHILOSOPHY. 

[NEW SERIES.] 



OCTOBER 1828. 



XL II. On the Method employed in the Trigonometrical Sur- 
vey for Jinding the Length of a Degree perpendicular to the 
Meridian. By J. Ivory, Esq. M.A. F.R.S.* 

TN the first volume of the Trigonometrical Survey, a method 
■* is given for finding the difference of longitude of two sta- 
tions lying nearly in the same parallel of latitude, without as- 
suming that the earth has any particular figure, and supposing 
only that it is nearly a sphere f . An important part of the 
Survey depends upon this method ; and, although its accuracy 
has heretofore been called in question, yet we see from the 
late volumes of the Phil. Trans, that it is now deemed suffi- 
ciently exact and unexceptionable in its principle. It is how- 
ever remarkable, that this method has never succeeded in prac- 
tice, or rather, has in every case led to results evidently wide 
of the truth. This failure it is usual to ascribe to errors in 
the observed azimuths ; but we may reasonably doubt whether 
this be the sole cause of deficiency, when we observe that the 
difference of longitude of the two stations, computed by other 
modes of solution unquestionable in point of accuracy, is al- 
ways found to depend on the compression of the spheroid. 
The method of which we are speaking, was first published in 
the Phil. Trans, for 1 790 and 1 795 ; it is therefore time to sub- 
ject to a strict examination a process which, although it has 
never been of any utility, is still employed in practice ; and 
as I have thrown out some doubts about the grounds of it in 
this Journal for May last, I deem it incumbent on me to as- 
certain fully its real character. 

Let A and m denote the latitude and azimuth at the first 
station; V and m' the same things at the second station; 

* Communicated by the Author, 
f Trigonometrical Survey, vol. i. pp. 154, 293. 
New Series. Vol. 4. No. 22. Oct. 1828. 2 I y the 



242 Mr. Ivory on the Method of folding the Length 

y the rectilineal distance of the two stations, or the chord be- 
tween them ; to the difference of longitude ; a the equatorial 
semidiameter, and e the excentricity of the elliptical meri- 
dians. Further, let $ stand for the angle of depression of the 
chord below the horizon of the first station : then y sin $ will 
be the perpendicular drawn from the second station upon the 
horizon of the first ; and the distance of this perpendicular 
from the plane of the meridian of the first station, to which 
plane it is parallel, will be equal to y cos <p sin m 9 because the 
azimuth m is the angle which the projection of the chord upon 
the horizon makes with the meridian. Now let x be the di- 
stance of the second station from the polar axis of the sphe- 
roid : then, co being the angle between the two meridians, it is 
obvious that the distance of the second station from the plane 
of the meridian of the first, will be equal to x sin co ; and in 
consequence of what was before proved, we shall have this 
equation, 

x sin co = y cos <p sin m. 
Next let R be the radius of a sphere which passes through 
both the stations, and touches the horizon of the first : then, 

sin * : =^r:' cc,s ^ = N/ ' 1 -ii?- 

If we conceive a plane to bisect the chord y at right angles, 
this plane will cut off from the normal to the earth's surface at 
the. first station, a part equal to the line R. Therefore R, like 
the radii of curvature of the spheroid, will always be little dif- 
ferent from a, the semidiameter of the equator ; and since y 
is always a small part of R, or of a, we may substitute a for 
R in the expression of cos <p, without danger of introducing a 
sensible error in any case that can occur in practice. We 
have likewise, from the nature of the elliptical spheroid, x = 

and thus we get, 



-e*sin*X' 

cos k' sin u y I yj. 

Vl-^sin 2 *' " « 4a"* 



sin m. 



Now, put sin — = Zr \ then, 



— V 1 — = 2 sin - '- cos ■£■ = sin 

a 4 a 1 2 2 



•: fi 



and the last formula will become, 



cos X r sin a> ♦ /> • 

- = sin p sin m. 



t/l— ei sin*>.' 

The like reasoning applied to the second station will furnish 
another similar equation. 

Thus 



of a Degree perpendicular to the Meridian, 243 
Thus we finally obtain, 

Cos tV = — cos x ' , cos M sin w = sin (3 sin m, 

Cos \I/ = — , cos \I/ sin « = sin B sin w'. 

Suppose now that a spherical triangle is constructed of 
which the base is equal to the arc /3, and the two sides to the 
arcs 90 — if/ and 90— 4/' : I say, that the angle of this triangle 
opposite to the base /3 is not sensibly different from w, the 
difference of longitude, when the two latitudes are nearly 
equal; and is exactly equal to it when the two latitudes 
are equal. In order to prove this, it is to be observed that 
a cos 4', a cos \[/, are the respective distances of the two stations 
from the polar axis of the spheroid ; and a sin fy V 1 — e 2 , 
a sin \(/ \/ 1 — e 2 , are their distances from the plane of the 
equator. Wherefore, because co is the angle between the two 
meridians, we have this expression for the square of the chord, 
viz. 

— = (cos \J/— cos v[/ cos co) 3 + cos 9 ^' sin 2 co + (1 — e z ) (sin \f/ 

—sin \[/) 2 ; 
or, which is the same thing, 

-^- as 2 — 2 (cos\(/ cos ty cos w + sin ty sin ty) — <? 9 (sin\J/ — sin \f/) 9 : 
but £* = 4 sin 2 — = 2 (1 —cos /3) ; and, hence, 

. cos /3 = cos \J/ cos v|/ cos co + sin \[/ sin \J/ + — (sin \j/ — sin \[/) 9 . 

Now, from this equation and the relation that is known to 
subsist between an angle of a spherical triangle and the three 
sides, it follows that w may be reckoned equal to the angle of 
the triangle opposite to the base /3, whenever the latitudes are 
so nearly equal that the term multiplied by e\ has no sensi- 
ble value; and when the latitudes are exactly equal, the equa- 
lity affirmed is rigorously true. But for the greater precision 
let us inquire, what variation the term multiplied by e 2 will 
produce in the arc /3. For this purpose suppose that /3 be- 
comes /3 + 8 6, then, 

Cos (/3 + 8 13) = cos v[/ cos 4/ cos co + sin \[/ sin \J/, 

~ „ { (sin X— sin X f ) a (sin X— sin A.') 

8 — _i i-.x _i 

^ sin 1 y 

the true latitudes being written for v[/ and \J/, and — for sin j3, 

in the expression of the small variation. In the instance of 
Beachy Head and Dunnose, we shall find 8 /3 = 0"*1 1, a quan- 

2 I 2 tity 



244 On finding the Length of a perpendicular Degree, 

tity far below the errors of observation. In this instance, and 
in all those where this method has been actually used, or where 
it can be supposed to apply, we may conclude that the angle 
of the spherical triangle opposite to the base /3, is equal to a>, 
the difference of longitude of the two stations. But in every 
spherical triangle, the sines of the angles are proportional to 
the sines of the opposite sides ; and hence, on account of the 
equations (x), we learn that m is the angle of the same triangle 
opposite to the side 90 — \J/, and m' the angle opposite to the 
side 90— vp. 

Having obtained a knowledge of all the parts of the sphe- 
rical triangle, if we apply to it one of the analogies of Napier, 
we shall get, 

*-*' 

cos — - — . , 

rp. « 1 m-\-m 

Tan T = . w x cotan -y-. 
sin-^- 

Now this formula is different from the method in the Trigo- 
nometrical Survey in no other respect, except that the arcs \J/ 
and \J/, which are what are called the reduced latitudes, come 
in place of the true latitudes k and X\ But as the reduced 
latitudes depend upon the excentricity of the spheroid, it fol- 
lows that the difference of longitude is no more independent 
of the figure of the earth in this mode of computation, than in 
any other. Because the difference of latitude is very small, 

we may write cos ~~ , or even the radius of the tables, in- 
stead of cos ■ ~ : and I have found, by reducing properly 
and putting e == — , 

e cos 8 — — I. 



Sin^p- = sin-^- x(l- 

The foregoing expression will now become 

x— x' 
cos / 

Tan T = , x+x > x cotan-^— x(l+ e cos*-±-), 

sin-y- 

or, in logarithms, 

Logtan. - = log! x+x , X cotan -T-J + Mecos 8 — . 

This, then, is the formula by which we must compute the dif- 
ference of longitude on a spheroid of which s is the compres- 
sion ; and if we make e = 0, it will coincide with the method 

in 



Mr. Ivory in reply to the Bulletin des Sciences. 245 

in the Trigonometrical Survey, and will give the difference of 
longitude on a sphere. 

But even the correct expression of the difference of longi- 
tude, which we have here investigated, has a disadvantage 
that makes it improper to be applied in practice ; namely, the 
result is always affected with the sum of the errors of the two 
azimuths, which is likewise heightened by the divisor of the for- 
mula. In the instance of Beachy Head and Dunnose, we have 

\ = 50° 44' 21", m = 96° 55' 58" 

V= 50 37 5 m'= 81 56 53: 

and with these data, the difference of longitude will be found 

equal to, ^ ^ ^ u ^ 

Now I have computed the three following values of the same 
difference of longitude from independent data; one, by the 
formula (A) at p. 190 of the last Number of this Journal, which 
is independent of the azimuths ; and two, by employing the 
formula (B) at p. 191, combining the azimuth at one station 
with the latitude of the other, the result not being sensibly 
affected in this mode of computation by any probable error in 
the azimuth ; viz. 

1° 27' 5"-62 

1 27 5 -63 

1 27 5 -61 
It appears therefore that the result obtained by the formula 
investigated in this article is in defect about ll", which can 
only arise from an error of about 9" in the sum of the azimuths. 

J. Ivory. 



XLIII. Some Remarks on an Article in the Bulletin des Sci- 
ences Mathematiques Physiques et Chimiques, for March 
1828. By J. Ivory, Esq. A.M. F.R.S. 8?c* 

T N the Bulletin des Sciences Mathematiques Physiques et Chi- 
■*• miques for March last, there is an article relating to the pa- 
pers inserted in this Journal, which treat of the attraction of 
spheroids and the figure of equilibrium of a homogeneous planet 
in a fluid state. The remarks of the author on the opinions 
I have ventured to advance on these subjects, seem to call for 
some notice from me, which I shall study to make as brief as 
possible. 

With regard to the attraction of spheroids, the usual ground 
of the dispute is shifted. The controversy has hitherto been 
confined to the law of attraction that prevails in nature; namely, 

* Communicated by the Author. 

when 



246 Mr. Ivory in reply to the Bulletin des Sciences, 

when the exponent of the attractive force is — 2 ; but on the 
present occasion, the author brings forward the case when the 
exponent of the attractive force is negative and greater than 2. 
I have no inclination to enter the lists on this new ground ; 
and I am persuaded that whoever will read attentively what is 
written in the Bulletin, will not blame Laplace for departing 
from the great generality aimed at in the third book of the 
Mecanique Celeste, and in his later writings confining his theory 
to the single case of an attraction inversely proportional to the 
square of the distance. 

In p. 155, the author proceeds to animadvert on what he 
calls my new principle of Hydrostatics, which he says has not 
yet been refuted by any geometer " (Tune maniere vraiment sci- 
entifique? Great was my astonishment on perusing what the 
author has written, to find that it does not affect in any re- 
spect what I have published concerning the equilibrium of a 
planet in a fluid state. This part of the Bulletin is mostly 
taken up with two demonstrations of the general equation of 
the level surfaces, or the surfaces of equal pressure, in a fluid 
mass in equilibrio. Now I have nothing to object to these de- 
monstrations. Applied to the case of a homogeneous planet, 
the meaning of the equation is this : The equilibrium of the 
planet requires that it be possible to divide the whole fluid 
mass into any number of strata separated by surfaces of equal 
pressure, which, beginning at a point within the planet, extend 
to the outer surface, and are included one within another*. 
My solution of the problem h is so far from being inconsistent 
with the general equation, or with the equivalent property of 
the level surfaces, that it is the only general method that has 
yet been found for rendering the existence of these surfaces 
demonstrative and certain f . 

In the usual theory, and particularly in the theory delivered 
in the Mecanique Celeste, it is affirmed that the perpendicu- 
larity of gravity to the outer surface is all that is necessary to 
insure the existence of the interior level surfaces, their gradual 
decreasing, and final concurrence in a point. But of this no 
sufficient demonstration is given ; and I contend that none 
can be deduced from the single principle of equilibrium as- 
sumed. I have done nothing more than add a condition which 
is wanting, without which trie problem cannot be solved. 

In reference to some of the author's remarks, it is to be ob- 

* See Clairaut, Figure de la Terre, Part. i. § xxi. 

f In prop. 4th, p. 166 of this Journal for September 1827, it is shown 
in what manner the general equation of the level surfaces is fulfilled in my 
solution : and it is proved that, without the condition I have added, the 
same equation could not be fulfilled, and there would be no equilibrium. 

served, 



on the Attraction of Spheroids, fyc. 247 

served, that in the investigation published in this Journal for 
September 1827, there is no mention made of strata infinitely 
thin, nor of the addition or subtraction of such strata. 

After all, the question is not about this or that principle of 
Hydrostatics, nor this or that theory. The real question is, 
Whether the investigation I have published, more especially in 
this Journal as above cited, is, or is not, rigorous and exact ; 
and whether I have been able to deduce, from the supposition 
that there is an equilibrium, the conditions without which it 
cannot subsist, and which are sufficient to determine the figure 
of the fluid. The proper way of answering this question is to 
examine the solution itself. And as this is the fairest way 
of deciding the matter, so it is the shortest and the easiest ; 
for the whole investigation is divided into distinct propositions, 
which hardly occupy three pages of this Journal; and it in-* 
volves no nice nor intricate point of analysis, which is often in- 
troduced because the true principles of the problem have been 
viewed in an improper light. One thing at least is certain, 
that M. Poisson has not succeeded in detecting any flaw in 
my reasoning; and the animadversions of the present critic 
leave the matter just where it was. 

I shall immediately set about reviewing all that I have writ- 
ten on this subject, in order to correct any inaccuracies that 
may have escaped me, and to clear up any obscurities that may 
have occurred in taking a new view of a difficult subject. I 
hope to be able to guard my theory against the objections and 
attacks to which it has hitherto been liable, in a short work 
which I will address to the Royal Society; thinking that, 
amidst the more interesting and fashionable objects that oc- 
cupy their attention, that learned body will not entirely pro- 
scribe a capital part of the philosophy of Newton, which is 
still very imperfect, notwithstanding the researches of so many 
philosophers. I have also another reason for making this 
destination of my work : the Royal Society, as the public pro- 
moters of science, have imposed upon them the duty of se- 
curing to every one the discoveries he may make. 

But the author of the critique in the Bulletin is not content 
with animadverting on what I have done; he is obliging enough 
to carry his attention to what he supposes I am doing. I as^ 
sure him, however, that he has been misinformed about the 
nature of my present occupations, and that he entirely mis- 
conceives my views of the equilibrium of a planet of variable 
density. This problem I have solved long ago; and the re- 
sult of my investigation has already appeared in this Journal 
for July 1826. My analysis is not indeed published; because 
it is too bulky for the pages of this Journal, in which I have 

been 



24-8 Prof. Encke on the Construction and Arrangement 

been led, from very peculiar circumstances, to communicate 
what I write to the public. But in the work I have announced, 
I will treat this subject fully ; and my critic will then see how 
far he is mistaken in supposing that I wished to introduce the 
consideration of particles attracting at very small distances. 

J. Ivory. 



XLIV. On the Construction and Arrangement of the New Berlin 
Astronomical Ephemeris. By Professor Encke*. 

"W7"E observe the bodies of our solar system not from the 
* ™ central point of their motions, but from a point on the 
surface of the earth which has a double motion about this cen- 
tral point. It would therefore be desirable to learn by the 
ephemerides the position of the heavenly bodies with respect 
to three points; — the centres of the sun, and the earth, and the 
place on the terrestrial surface for which the ephemerides are 
calculated. The peculiar modifications however, applicable 
to every body in our system, are such as to leave no more than 
two points for each of them, for which the more accurate data 
are requisite. For the planets which are more distant, and 
which are less regularly observed throughout the whole year, 
the reduction from the centre of the earth to a definite point of 
its surface is so simple, that nothing is required to facilitate the 
calculation ; and for the sun and the moon, the relations to the 
centre of the whole s}'stem disappear, being implied with re- 
gard to the former, and unnecessary for the latter, whose course 
is referred only to the earth. In every opening of the book 
the two pages present, accordingly, for every body of our so- 
lar system the polar coordinates with respect to two points ; 
for the moon and the sun, those relating to the centre of the 
earth and the place on the earth (Berlin) (with respect to the 
latter point the distances, however, have been omitted, as un- 
necessary); for the planets and the satellites of Jupiter, the 
heliocentric and geocentric places, or that which will supply 
their places. The coordinates which immediately involve the 
results of the observations are referred to the equator, the 
others to the ecliptic. The small planets make the only ex- 
ception to this. The time which is everywhere applied, ex- 
cept where it is expressly mentioned, is mean time. The be- 
ginning of the day has been taken at noon, and the hours are 
counted to 24; so that hours below 12 are those of the after- 
noon, and the hours above 12 diminished by 12 h are the 

* From the New Berlin Ephemeris : being a translation of a portion of 
the Appendix to that work, as promised in our Number for August, p. 145. 
— Edit. 

hours 



of the New Berlin Astronomical Ephemeris. 249 

hours of the forenoon of the civil day following the one cor- 
responding to the given hours of the astronomical day. All 
longitudes, latitudes, right ascensions and declinations, refer 
to the true or apparent equinox, and the true or apparent po- 
sition of the different planets, for which Mr. Bessel's determina- 
tions of the nutation and obliquity of the ecliptic have been 
throughout applied. All data have been calculated from the 
tables without neglecting any one correction, and have been 
given exactly as resulting from the tables. A main object of 
these ephemerides has been to save to the astronomer the 
trouble of the tedious immediate calculations from the tables. 

The almanac contains, besides the chronological part and 
the explanation of the signs, four principal sections; viz. 
1. Ephemerides of the sun and moon. 2. Ephemerides of the 
planets and their satellites. 3. Positions of the stars. 4. Phe- 
nomena and objects of observations. 

For the sun and the moon every month has six pages, which 
for the facility of reference have been separately marked with 
Roman figures, I — VI. The first page contains the data neces- 
sary in solar observations. Their epoch is, therefore, the ap- 
parent noon at Berlin. After the first two columns, the days 
of the month and of the week, follows the mean time at the 
moment of the apparent noon, usually called the equation of 
time ; next, the right ascension of the sun, or the sidereal time 
at the apparent noon ; then the declination accompanied by 
the column, log. \t* (agreeably to Gauss's notation, in the manner 
of Professor Schumacher's auxiliary tables), which is the log. 
of the change of declination in 48 hours expressed in seconds 
of a degree from the preceding noon to the following one, or 
very nearly the change of declination for 48 hours appertain- 
ing to the noon opposite to which it stands in the ephemeris. 
Lastly, the sidereal time is given which the sun employs in 
passing over the wire of a transit. The opposite page II. con- 
tains the data for the sun which are employed in calculations 
of the planets. Their epoch is, therefore, the mean noon. The 
columns of days of the month and of the week are followed 
by the sidereal time at the moment of the mean noon, which is 
requisite for reducing an observation made by sidereal time to 
mean time. Next follow the longitude, latitude and radius 
vector of the sun. In the former, the aberration has not been 
applied, so that the given numbers must be immediately used, 
without any correction, in converting geocentric places into 
heliocentric ones, and vice versa. Lastly, the semidiameter of 
the sun is given, which is used in observations of declination. 

These data have been derived from the solar tables of Car- 
lini, improved by Mr. Bessel's corrections, which he has had the 

New Series. Vol.4. No. 22. Oct. 1828. 2 K kindness 



250 Prof. Encke on the Construction and Arrangement 

kindness to communicate to me. The columns of the time of 
transit and semidiameter of the sun are taken from BesseFs 
tables. The calculations have been most rigorously executed, 
and the latitude has been duly taken into consideration in the 
right ascensions and declinations. We may therefore hope, 
that, should even new tables of the sun be published before 
1830, the calculated positions will not greatly deviate from the 
true ones. 

The following four pages III — VI. contain the positions of 
the moon. The odd ones III. and V. contain the longitude 
and latitude, and the right ascension and declination, of the 
moon for every mean noon and midnight at Berlin. The 
present arrangement of these columns, in which the data fbt 
noon are not separated from those for midnight, as was hitherto 
usually done, appeared to be more convenient for taking the 
differences. On the opposite pages IV. and VI. are contained 
in the first place for the same epochs the horizontal equatorial 
parallax of the moon which supplies the place of the distance, 
and the diameter as seen from the centre of the earth. Next 
follow the three columns which refer to the moment of the 
moon's culmination at Berlin ; viz. the mean time of the moon's 
superior or inferior culmination, with the right ascension and 
declination corresponding to that moment, likewise referred 
to the centre of the earth. The upper and lower culminations 
are distinguished by the letters O and U. 

The two last columns give the times of the sun and moon's 
rising and setting, designated by the letters A and U. Below 
the odd pages III. and V. are placed the changes of the moon 
by mean time; below the even* ones, the times of perigee and 
apogee. 

The columns contained on the even pages are intended to 
facilitate the calculation of the apparent place affected by 
parallax; this will be treated of more in detail in another 
place. For this reason the apparently misplaced times of the 
sun's setting have been here inserted. Those times have be- 
sides for astronomers no other essential importance, except as 
far as the visibility of other heavenly bodies is dependent on 
them. The moments of the sun and moon's setting are, as always 
where there is no particular mention, given in mean time. 

All the calculations for the moon have been deduced from 
Burckhardt's tables, from which the later ones of Damoiseau 
do not appear ever to deviate considerably. The accuracy of 
the tables of Burckhardt having been much confirmed of late 
years (in the opinion of a very competent judge), they have as 
yet been preferred to the others founded more on theory. 

For the careful execution of this portion of the work, I am 

indebted 



of the New Berlin Astronomical Ephemer is. 251 

indebted to the persevering industry of Messrs. Herter, Wok 
fers, and Deinhardt, who have divided between them the cal- 
culation of all the longitudes and latitudes, as well as right 
ascensions and declinations, immediately from the tables. This 
being the first considerable astronomical calculation executed 
by any of these gentlemen, no pains have been spared to dis- 
cover and to correct all errors by taking the first four differ- 
ences. Wherever a correction of 0"\5 would bring out more 
regular differences, the whole calculation has been revised. In 
a few such cases it was necessary to retain the calculated num- 
bers unchanged ; and this quantity may therefore be consi- 
dered as the maximum of error. Errors of 0"'3, and less, could 
not be avoided, on account of the great number of equations. 
The parallax and semidiameter have been put to the same 
test. The manner of calculating the other columns will be 
given in another place. This section is concluded by a table 
in which the apparent obliquity of the ecliptic, the true paral- 
lax of the sun, the aberration of the sun's longitude, the equa- 
tion of the equinoctial points, and the longitude of the moon's 
node, have been placed together for every tenth day. The 
aberration is to be added algebraically with the sign given to 
it to the values contained on page II., in order to obtain the 
real longitude of the sun, as it will be observed. The sign of 
the equation of the equinoctial points denotes that the mean 
equinox is in this year behind the true equinox, or that all 
mean longitudes are greater than the true ones. The moon's 
node is given according to Burckhardt. 

Next follow the ephemerides of the planets and satellites. 
For the older planets the page on the left contains the helio- 
centric places, together with the columns of rising and set- 
ting ; while that on the right contains the geocentric places, 
with the passages over the meridian in mean time, the former 
referred to the ecliptic, the latter to the equator, the right as- 
cension being given in time. For Mercury and Venus the 
places have been calculated for every other day, and the mean 
noon at Berlin ; for the others they are calculated for every 
fourth day, and the mean midnight at Berlin. 

The calculations for Mercury have been undertaken by 
Mr. Herter. One of the corrections of the tables of M. Lin- 
denau, first noticed by Professor Schumacher, which refers to 
the radius vector, has been inadvertently omitted. This trifling 
neglect affects, however, the last figures only of the radius 
vector, and seems to lie within the limits of uncertainty of even 
Lindenau's tables. The fourth differences have likewise been 
taken in this case, but their magnitudes were in some parts 
such as to afford no certain criterion of the absolute correct- 

2 K 2 ness 



252 Prof. Encke on the Construction and Arrangement 



s* 



ness of the calculation. The places of Mercury might, should 
it be wished, in future be given for every day of the year. 

The calculations for Venus, and the greater part of those for 
Jupiter and Saturn, have been performed by Mr. Wolfers. For 
Venus and Mars, the tables of M. Lindenau ; for Jupiter, Sa- 
turn, and Uranus, the latest tables of Bouvard, — have been 
used. 

The time of passage over the meridian is meant only ap- 
proximately ; the astronomical use of it being supplied by the 
right ascension in time, which is likewise given. Calling the 
sidereal time at the moment for which the right ascension a 
has been calculated, the time given in the column, headed 
" Planet on the Meridian," is 

For the superior planets a— 

For the inferior planets 12 h + a— 

A corrective factor = -^^-— ar J ay ought to have been ap- 

planetary day ° r 

plied to a — ; but this factor would not have produced any 
great change, and if required, its effect may easily be calcu- 
lated. From the time of passage over the meridian and the 
declination on that day, the times of rising and setting have 
been calculated, which are therefore not to be considered as 
rigorously correct. The times of rising and setting of the 
heavenly bodies have in general been calculated with due re- 
gard to refraction, for which purpose Bessel's horizontal re- 
fraction of 36' has been adopted. For the moon the mean 
parallax of 57' has besides been taken into account. The other 
heavenly bodies are, therefore, in those moments 36' below, 
and the moon 21', above the plane passing through the centre 
of the earth, and parallel to the horizon. 

The four new planets make an exception; for there the 
geocentric place only is given, together with the auxiliary co- 
lumns. The form in which their perturbations are calculated, 
is such that the accurate determination of their places would 
require more extensive calculations than the possible use ren- 
ders necessary. In the same manner the determination of 
their heliocentric places would have caused a change in the 
form of calculation, which is in no proportion to the possible 
nse which might be made of them f For this reason the ele- 
ments for the time of the opposition have been rigorously de- 
duced, and then have been retained for the whole year. For 
each planet, however, more accurate daily positions have been 
given for the 28 days, within which the moment of opposition 
is contained. 

The perturbations of Pallas, Juno, and Vesta, have been cal- 
culated as far as the year 1830. For the first, the elements of 

Gauss 



of the New Berlin Astronomical Ephemeris. 253 

Gauss have been used ; for the second, those of Nicolai ; for the 
third, mine; which will appear in another place. For these 
three planets the errors will hardly amount to a minute. The 
planet Ceres, however, w r hose elements have not been further 
investigated since M. Gauss last corrected his Elements in the 
year 1809 (Elements, xiii.), and whose perturbations have not 
been completely developed, may deviate more considerably. 
In accordance with the last oppositions, the epoch of mean 
longitude has for the present been diminished by 14' for the year 
1 830. It is to be hoped that this correction will likewise have 
nearly approximated it to its true position. 

All data for the planets have been given, without any re- 
gard to aberration and parallax. On account of the former, the 
given places do hot belong, with respect to the actual obser- 
vations, to the moments h and 12 h , but (calling the geocen- 
tric distance of any planet A ) to those moments (viz. h or 
12 h ) + 493"*2. A (time). 

With regard to the satellites of Jupiter, which then follow, 
it was customary to give, besides the eclipses which supply the 
place of the heliocentric place, a graphical representation of 
their geocentric position with respect to Jupiter for a certain 
definite moment. But as their position is thus only obtained 
for a single moment of time, it has appeared to me that the 
advantage of an ocular graphical representation is overba- 
lanced by the concomitant want of being deprived of the means 
of deducing the geocentric position for any other given time. 
I have therefore preferred giving the time of the superior 
geocentric conjunction, together with the corresponding ratio 
of the axes of the apparent ellipsis of the orbit of the satellite, 
accompanied by the tables of reduction ; by means of which, 
from the time elapsed since the last preceding conjunction, the 
geocentric coordinates of the satellite, with respect to the 
centre of Jupiter, may be derived. 

It is to be observed that these results have been founded, both 
as regards the derivation of the superior geocentric conjunction 
from the heliocentric conjunction and the time of revolution, 
on which the tables of reduction are founded, on the hypo- 
theses of the mean heliocentric synodic time of revolution of 
the satellite, and of the perfectly circular form of their orbits, 
while the true synodic geocentric revolution ought to have been 
taken. They may, however, should more accurate measure- 
ments render it necessary, be corrected without any great 
trouble. The difference will always be small, and quite insig- 
nificant as to inspection. 

By this arrangement the observer of eclipses is, at the same 
time, enabled accurately to determine the place of emersion, 

on 



254 Prof. Encke on the Construction and Arrangement 

on which account the coordinates for those moments have not 
been added. 

The occultations of the first two satellites are on the page 
on the left ; those visible in Berlin are distinguished by an 
asterisk (*). On the right hand are contained the times of the 
superior geocentric conjunction with the corresponding ratio 

of the axis — , where a denotes the great, and b the small semi- 
axis. The sign — signifies that the satellite has in the su- 
perior conjunction a southern jovicentric latitude, or that we 
see the southern part of the plane pf the satellite's orbit. The 
sign + would accordingly denote the visibility of the northern 
part of it. At the end of the column for each satellite will be 
found the tables of reduction belonging to it. 

Their use may be learnt by the following example. Let it 
be required to find the position of the two satellites for April 
14th, 15 h 14/*2; then the next preceding geocentric conjunc- 
tions are to be taken together with the value of ~ for the 
given time. ^ ^ ^ ^ - h ^ _ Q ^ 

II. 13. 9 57*1 -63*7 

These deducted from the given time present the arguments 
for the tables of reduction 

Sat. I. d l h 20'-7 
II. 1 5 17-1 

For these we take from the tables 

Sat I. x = +1*13, 3/ =+5*59 
II. = +7*55, = -5-01 

The latter ones (viz. j/ ) divided by — then give, with proper 

regard to the signs, these positions : 

Sat. I. x — +1-13, Sat. II. x — +7*55 
y— —0-09. y = +0-08. 

Both x and y are expressed in radii of Jupiter ; x is the abscissa 
on the great axis of the ellipsis of the satellite taken positively 
in the direction of its motion or eastward ; y in the direction 
of the jovicentric latitude, the northern one being positive. In 
the field of the telescope a positive x will indicate the satel- 
lite's position to the right of Jupiter, and a positive y its posi- 
tion to the south of it. It appeared unnecessary to give the 
angle which the great or small axis forms with a circle of 
latitude or declination, as the belts of Jupiter sufficiently ex- 
hibit the position of the great axis. 

For the third and fourth satellites the eclipses have not been 
given, but instead of them the times of the middle of the eclipses 

taken 



of the New Berlin Astronomical Ephemeris. 255 

taken in such a manner as if they were visible ; and the semi- 
duration is added in order to reduce to the same form the mo- 
ments in which no eclipse takes place. The calculation has been 
executed by M. Wolfers from Delambre's latest tables of the 
satellites. However well founded M. Hansen's remark re- 
specting the incorrectness of the table of equation C for the 
first satellite may be, yet it was preferred to retain this* table 
unchanged, partly because some other corrections in the pre- 
face likewise require amendments, partly because it is doubtful 
whether Delambre has not compared the observations with 
tables which contained the same small deviations. At any 
rate the difference will seldom amount to 1" for the first satel- 
lite, and for all the others it will always be within this limit. 
The last page of this section contains the elements for the geo- 
centric form of the ring of Saturn, with the explanation of the 
notation. For the node and inclination, Bessel's paper in the 
Astron. Jahrbuch for 1829, and for the dimensions of Saturn's 
ring, the measurements of Struve in the Astron, Nachr. v. 
No. 97, have been used. 

The following section contains the places of the pole star, 
8 Urs. Min. and of Bessel's 45 stars, after the model of the 
excellent auxiliary tables of Prof. Schumacher, with this only 
difference, that the inferior culminations of the two polar stars 
have not been given. The apparent places refer to the time 
of culmination at Berlin, and the asterisk denotes that in that 
place not ten, as everywhere else, but eleven sidereal days are 
to be taken. 

The mean places on which these positions are founded are 
enumerated together in the beginning. Their comparison with 
the corresponding numbers in the auxiliary tables for 1827, 
has shown that there is a small deviation in some of those stars 
only, which Bessel has not introduced into his fundamental 
catalogue, probably owing to a differently assumed proper 
motion. They are all founded on M. Bessel's latest determi- 
nations. The calculation has been performed with great care 
by M. Dannemann. 

The daily aberrations for the polar stars are given below 
for the culminations. Its values for the other stars are to be 
found by the side of the last of them, u Andromeda. For the 
reduction of other stars from their mean places in the begin- 
ning of the year to the apparent ones at any other time, two 
tables have been added, whose construction will be evident 
from the formulae * at the beginning of this section. The first, 

* The tables here described, together with the formulae alluded to, we 
hope to be enabled to publish in a future Number of the Phil. Mag. and An- 
nals.— Edit. 

the 



256 Prof. Encke on the Construction and Arrangement 



&' 



the well-known one of Bessel, is accompanied with the neces- 
sary illustration of the manner of forming the argument It is 
arranged by sidereal days. The other, which proceeds by 
mean solar days, is more convenient, if, as is the case in obser- 
vations of comets, a single position only of a star is required ; 
as it is constructed after Gauss's general tables, and does not 
require the calculation of the constants a,b 9 c,d. A small dif- 
ference in the elements on which these tables are founded, which 
has been noticed too late, causes a want of rigorous agreement 
in the results ; but the difference never exceeding hundredth 
parts of a second, it is of no consequence for practical pur- 
poses. 

The last section contains the principal phenomena for ob- 
servations. 

In the first place the eclipses of the moon and sun are suffi- 
ciently described for determining the places on the earth where 
they will be visible. For those who are fond of constructions, 
the elements from which the phenomena may be determined, 
have been added at the end. In future the solar eclipses, which 
are interesting for our part of the world, will be treated rather 
more in detail. 

Next follow the constellations of the planets. In these, re- 
gard has been had to the two principal points of the elliptic 
orbit, the perihelium and aphelium, the four principal elements 
of the position of their heliocentric orbit, the two nodes, and the 
maximum and minimum of their latitude, to the four principal 
elements of their synodic paths £ 6 n , or those which corre- 
spond to them for the sun and superior planets. 

I am not acquainted with any astronomical use of the con- 
junctions of the moon and stars commonly given in astrono- 
mical almanacs. It appears to me that the columns of right 
ascension and declination of the moon render this part quite 
superfluous ; as the arrangement of our present catalogues of 
stars is such that there can be no trouble in determining the 
stars near which the moon will pass. These have, therefore, 
been omitted ; but, on the contrary, the possible occultations of 
planets have been carefully investigated : and where there is a 
possibility of an occultation, should it even not really take 
place at Berlin, the conjunction has been noted. In the year 
1830, Venus only will undergo an occultation at Berlin. 

In the present almanac for the year 1830, no occultations 
of fixed stars by planets have yet been inserted ; as I enter- 
tained doubt respecting the extent to which these investiga- 
tions ought to be carried. An examination has proved that 
no bright star down to the third magnitude will experience 
such an occultation. I will leave it to the decision of astrono- 
mers 



of the New Berlin Astronomical Ephcmeris. 257 

mers whether this examination ought to be extended to the 
stars of the fourth, fifth, and sixth magnitudes. A rigorous 
investigation to that extent insuring the certainty of not 
one having been omitted, would require considerable labour. 
Next come the moon-culminating stars, or those stars which 
being near the parallel of the moon at the time of her culmi- 
nation are likewise not far distant from her in time. It was 
originally not my intention to give them. However success- 
ful the observations have been by the ready publication of 
them in Prof. Schumacher's Astr. Nachr., they will then only 
be of use if a single catalogue only is annually published. 
Nothing but the request of a much esteemed correspondent, 
in consequence of the fear entertained in the beginning of this 
year that the publication of such a catalogue would be inter- 
rupted, has induced me to give the present one; should, how- 
ever, another catalogue containing, perhaps, a greater num- 
ber of bright stars be sent from England, I would request 
that this one should be laid aside. Its construction has been 
performed rather hastily ; more convenient stars might per- 
haps have been selected, especially for the second limb of the 
moon. 

In the application of it for ascertaining longitudes even with 
only moderate transits, it will be adviseable to consult prin- 
cipally the excellent paper by Prof. Nicolai, Astr. Nachr. ii. 
No. 26, and those by Prof. Bessel and M. Hansen on the cal- 
culation of the horary motions of the moon, Astr. Nachr. ii. 
No. 33. 

The notation and the places of the stars, both of the moon- 
culminating stars and of those mentioned in the list of occulta- 
tions which follows, have been taken from the excellent Cata- 
logue of zodiacal stars, by which Mr. Baily has conferred a 
valuable benefit on the astronomical public. 

From this Catalogue all those stars have been inserted 
which will be occulted during the time of the moon's being 
above the horizon, while the sun is below it. Sometimes those 
have likewise been mentioned which are so nearly approached 
by the moon's limb, that a calculation only could decide whether 
an occultation would take placeor not. For bright stars, the 
occultations which happen in the day-time, especially those 
of a Tauri, have likewise been inserted. Some immersions and 
emersions which happen below the horizon of Berlin, have still 
been given, because they may be visible in other places. 

The headings show the contents of the columns of this 

section. The two columns " Ort " (place) indicate in what 

point of the moon's disc the immersions and emersions take 

place : the degrees being counted from that point of the disc 

New Series. Vol. 4. No. 22. Oct. 1 828. 2 L which 



258 Mr. Meikle on an improved Syphon-Hydrometer. 

which has most northern declination, through east, south and 
west, to 360 degrees. The immersions happen, therefore, with 
few exceptions in the two first quadrants, and the emersions 
in the two last. 

After the occultations of stars follow the mean places of 
the stars occulted, taken from Baily's Catalogue, and so ex- 
pressed as they are wanted in the calculation of the occultations, 
which forms the subject of another part of this book*. 

The auxiliary tables which then follow will be explained in 
the paper just alluded to. The horizontal equatorial parallax 
here given, belongs to the moment of the moon's culmination ; 
and the quantities Aa and A I added to the mean place of a 
star for 1830, give very nearly the apparent place of each star 
which can be occulted by the moon. 

The uncertainty about the extent of the calculation and 
the distribution of the different parts, however worthy of a 
place in this almanac, has caused such frequent changing and 
copying, that possibly some single errors may thereby have 
been introduced. Should, therefore, some erroneous data oc- 
cur, (for the communication of which I shall be very thankful,) 
I request that the blame may not be laid on the labours of 
my coadjutors, who have performed their part of the work with 
great sacrifices. Every imperfection which may be pointed out, 
and every improvement both in form and matter which may 
be suggested, shall be duly attended to. 

The typographical beauty of the printing, a production of 
the Academical Press of this city, which has been carried to a 
high degree of perfection by a great sacrifice on the part of 
the whole Academy, and particularly of an individual member 
of it, one of those whose services are most in request, — will, it 
is hoped, satisfy every one as a worthy accompaniment, without 
laying any claim to ornament or splendour. On a close ex- 
amination, judges in these matters will not fail to perceive the 
careful management of the superintendent of the press, who 
has spared no pains in the first arrangement to give all the aid 
of his experience to the execution of my wishes. 



XLV. On an improved Syphon-Hydrometer. By Mr. Henry 
Meikle f. 

T N the Philosophical Magazine for September 1 8 26, (vol. lxviii. 

p. 1 66) I proposed an instrument to be used as a hydrometer, 

consisting of an open glass tube thrice bent, so as to have four 

* The part of the Ephemeris here mentioned, will probably appear in 
a future Number of the Phil. Mag. and Annals.— Edit. 
f Communicated by the Author. 

straight 



Mr. Meikle on an improved Syphon-Hydrometer. 259 

straight parallel legs; and though alittlecomplex,it has obviously 
the property of being free from the effects of capillary action. 
In the Edinburgh Philosophical Journal for January 1827, a me- 
thod is given for applying the simple syphon to the same pur- 
pose, but which is not so entirely unaffected by capillary ac- 
tion. The same method, however, appears to be still suscep- 
tible of considerable improvement, so as to be rendered one of 
the simplest, and at the same time furnishing a pretty accurate 
instrument What I would suggest, as likely to render a simple 
glass syphon very convenient as a hydrometer, is merely to 
put a small hole in its upper or bent part. On immersing each 
leg of such a syphon in a separate liquor, a portion of the air 
escapes through the hole, and allows the liquids to rise in the 
tubes to the level of their cisterns. If we now apply the finger 
to the hole, and raise the instrument, I need scarcely say, not 
wholly out of the fluids, the liquors will be raised in the tubes 
by the pressure of the atmosphere, so as to form columns ele- 
vated to heights above their respective cisterns inversely pro- 
portional to their specific gravities. For the weights of the 
two columns must obviously be equal ; each being the difference 
between the pressure of the atmosphere and that of the in- 
cluded air. 

If the tube be pretty wide, the effect of capillary action may 
in most cases be neglected: so that, the one column being 
water, we divide its length by that of the other liquid, and ob- 
tain a quotient which is the specific gravity of the latter. But 
the effect of capillary action may be easily obviated altogether, 
by holding the syphon at two different heights, and noting the 
corresponding columns. Thus if at one height we have a co- 
lumn of water =W, and at another height = w; while the 
corresponding columns of another fluid are respectively A 
and a ; the specific gravity of the latter, freed from capillary 
action, is 

A-a ' 

For, if x be the capillary part of the column of water, and y 
that of the other fluid, we should correct the columns for ca- 
pillary action, by diminishing them respectively by x and y ; 
whence the specific gravity becomes 

W — x w—x ~W—w 



A-a 



We thus obtain the specific gravity free from capillary action, 
by dividing the difference of the columns of water by the dif- 
ference of those of the other fluid. The greater these differences 

2 L 2 can 



260 Mr. Meikle on an improved Syphon- Hydrometer. 

can be made, so much the better ; even using, perhaps, for the 
shorter columns the mere capillary elevations. 

In transparent liquors, we may make the one pair of co- 
lumns A and W to be depressions under the surfaces of the 
liquids contained in glass cisterns ; which may be effected by 
immersing the instrument with the hole previously stopped to 
confine the air. The depths of the depressions, when in- 
creased respectively by x and y, should, like the former co- 
lumns, be inversely as the specific gravities of the liquids. 
Consequently the required specific gravity becomes 

W-(-x w-x W +■ w 



A-f y ' " a-y ' A + a ' 

which, as the numbers may be larger, is likely to be more ac- 
curate than the former. For in this case we obtain the spe- 
cific gravity by dividing the sum of the elevation and depres- 
sion of the water by the sum of those of the other fluids 

There is still another case in which all the columns may be 
depressions, and which obviously makes the specific gravity 

W -f x w -\- x W—tv 

~ A +V ' " + y " ' A-a' 

where the rule is the same as in the first case. I may remark, 
that in all the cases, we might use in place of one of the pairs 
of columns, the mere capillary elevations, with proper signs. 

As a hole may be apt to weaken a glass tube, especially at 
the curved part where it should be strongest; two straight 
pieces of glass tube may be joined, as I have done, by means 
of a bit of bent tin-tube. The hole may then be more easily 
made, and will be less apt to weaken the instrument. The legs 
of the syphon should be graduated or divided into small equal 
parts. This may be very easily done by merely transferring 
to the tubes, with the assistance of a square, the divisions which 
are already made on any scale of small equal parts. It is ob- 
vious that the legs ought to be parallel. 

Nearly allied to the syphon-hydrometer, is a more complex 
instrument, called a pump-areometer. It is so named, from 
its being furnished with a pump at its upper part for exhaust- 
ing the air to induce the liquids to rise. The requisite de-. 
gree of exhaustion, however, is so very trifling, that it may be 
effected, were it in the least necessary, by merely sucking with 
the mouth at the orifice of a stopcock attached to the top of 
a syphon. Henry Meikle. 



XLVI. A new 



[ 261 ] 

XLVI. A new Account of the Genus Echeveria. By A. H. 
Haworth, Esq. F.L.S, fyc. fyc. 

To the Editors of the Philosophical Magazine and Annals. 
Gentlemen, 
TT AVING just examined and described a fine new succulent 
■*■"■" plant at Mr. Tate's Nursery in Sloane-street, which he 
has recently raised from Mexican seeds, and which is now 
blooming for the first time in Europe, amongst many other 
equally rare and well-managed plants ; I send you hereunder 
a full account of it, and four other species of the same genus; 
to which I have added all their synonyms. 

This new plant, belonging to DeCandolle's new genus 
Echeveria, I have called, from its ample leaves, Echeveria 
grandifolia. 

In my ninth decade of new succulent plants, published in 
your Journal in 1826, I announced to you (inter alia) that 
Cotyledon coccinea of Cavanilles, and Cotyledon umbilicus of 
Linne, would each form the type of a new genus, but for 
want of proper specimens regretted my inability at that time 
to give you sufficient characters. This, however, is now the 
less to be lamented, as DeCandolle has done it for us, in the 
third volume of his Prodromus, just published ; and to the 
above-mentioned Cotyledon coccinea has added my Cotyledon 
ccespitosa, (which is a native of California, although we used 
to think it African,) and two new species from Mexico. 

If you can find room for this communication in the next 
Number of your Journal, you will much oblige 

Your old correspondent and friend, 
Chelsea, Aug. 10, 1828. A. H. Haworth. 



Ordo Naturalis. 

Crassulacece DeCandolle. Sempervivce Juss. &c. — Cotyledones 
americance Auctorum. 

Genus, Echeveria DeCand. Prod. 3. 401. 
Generis Character. 

Calyx 5-partitus, sepalis distantibus valde foliiformibus, prae- 
inaequalibus basi coalitis. Corolla pentapetaloidea penta- 
gona campanularis. Petala inferne concreta erecta ri- 
gidula acuta crassa, basi inter calycis folia, extus gibba, 
intiis scrobiculata : duobus exterioribus petalis insuper 
tria interiora, arete imbricatim adpressa. Stamina 10, 
basi cum petalis longioribus concreta. Squama: ordinariae 

breves 



262 Mr. Haworth's Description of the Genus Echeveria. 

breves subquadratae albae, alternae crassiores cerinae, 
omnes in petalorum scrobiculis nidulantes. Carpella 5 
erecta, in stylos acutos desinentia. 

Siiffrutices Mexicani parvi succulenti glauci. Folia 
basi soluta : rosularia sed alterna, integra, cum mucro- 
nulo, at saepius valde obtusa, et in spicis florigeris folio- 
losis, pedetentim in bracteas numerosas magnas subdi- 
stantibus omnino foliiformes abeuntia. Flores valde brac- 
teati, spicati, s. paniculati, vel cymosi, et tunc secus cymae 
ramos sessiles, coccinei flavive. 

Specierum Characteres. 
* Suffrutices, floribus paniculatis spicatisve, coccineis. 

grandifolia. E. (great-leaved) foliis orbiculato-cuneatis grosse 

1. petiolatis, floribus paniculato-spicatis. 

Habitat in Mexico. 

Floret Aug. Sept. G. H. \. 

Caudex in nostro exemplo, in caldario, apud Dom. 
Tate, in secundo anno triuncialis diametro subunciali, 
cylindricus carnoso-lignescens radiculos exiguos terrain 
versus exerens. Folia numerosa conferta ambienter 
multifaria, seu in rosulam laxam digesta, patenti-re- 
curvula dodrantalia plusve incurvo-concavula, et in 
petiolum carnosura subsemunciam crassum obtuse ca- 
naliculatum attenuata, pruinoso glauca rufo marginata 
integra rariusve minutim asperiuscula ; subtus, basin 
versus praecipue vivaciter glauco-purpurascentia : et 
denique morientia inania lorea persistentia. Florum 
paniculae sesquipedales, bracteatim foliolosae, axillares 
teretes uti folia caeruleo-glaucae ; bracteis erectis lan- 
ceolatis mucronulatis (magis quam vera folia) distanti- 
bus sensim sensimque minoribus, et Sedi more singu- 
lariter basi plane obtuseque solutis. Calyx sepalis 5 
valde inaequalibus bracteis brevioribus omnino folii- 
formibus (excepto basi non soluto) tribus caeteris duplo 
majoribus, quarto minore, quinto minuto. Corolla 
fere semunciam longa, calyce brevior rubro-aurantiaca, 
rore roseo-glauca purpurea ve. Stamina 10, petalis 
humiliora alba, antheris erectis polline luteo. Carpella 
grossa, alba in stylos virides abeuntia, Caetera fere ut 
in E. coccined, infra descripta, at non recte vidi. 

gibbiflora. E. (gibbous-flowered) foliis planis cuneiformibus 

2. acute mucronatis ad apices ramorum confertis, pani- 
cula patente, floribus secus ramos breviter pedicellatis. 
DeCand.Prod, 3. p. 401. 

Habitat 



Mr. Haworth's Description of the Genus Echeveria. 263 

Habitat in Mexico. % . 

Petala basi albida, apice subcoccinea. DeCand. 1. c. 

coccinea. E. (pubescent) mollis : ramulis foliisque spatulato- 

3. lanceolatis pallescente dense puberulis, florum spicis 
axillaribus elongatis foliolosis. 

Cotyledon coccineum. Cav. Ic. 2. t. 170. — Nob. in 
Suppl. PI. Succ. p. 26. A.D. 1819.— Lodd. Bot. Cab. 
t. 832. — Echeveria coccinea. DeCand. Prod. v. 3.p. 401 . 

Habitat in Mexico. 

Floret autumno, hyemeve. G. H. \ . 

Suffrutex sesquipedalis, parum et alterne raraosus. 
Mores dense elongato-spicati, Spicce sub foliorum capitu- 
los adscendentes thyrsiformes bracteatim foliolosae, su- 
perne fere comosae, post florescentiam longum per tem- 
pus indurate denudatae persistentes. Flores duplo mi- 
noresquam m.E. grandrfolid 9 hoYYiont , a\.\te,x sessfles. Ca- 
lycis sepala subovato-lanceolata acuminata tumide car- 
nosa patenti-recurvula et inter bracteas irregulariter in- 
tertexta. Corolla 5-petaloidea campanulata coccinea, in- 
ferne pentagona, basi gibbulis 5, e foveolis totidem in- 
ternis nectariferis : laciniae (corollae) rectaa ovato-lance- 
olatae,acuminatae calyce breviores carina densius ciliato- 
puberula saturatiore; intus longe pallidiores glabrae fo- 
veolatas. Stamina 10, albo-lutescentia corolla subdimi- 
diatim breviora, 5 exteriora germinum basi inserta, 5 
alia in foveola supradicta dimidiatim flexuose adnata, 
solum superne libera, et 5 prioribus (staminibus) ali- 
quantillum humiliora. Anthers erectae subparalleli- 
pipedae emarginatae, basi cordatae, polline luteo. Car- 
pella 5, erecto-adpressa, cum stylis continuantibus ob- 
clavatis luteis, stigmate purpureo inconspicuo, lente he- 
misphaerico, et subinde ad lucem pellucente. 

Obs. Corollce laciniae intus argute canaliculatae, in 
quibus canaliculis insident exteriora filamenta, et ad 
eas adpressa, atque ad earum flexionem gibber parvus 
exstat utraque insuper apicem singulae foveolae supra- 
dictae. 

Ad basin singuli carpelli rudimentum solum squa- 
mulae ordinariae exstat tumidulum rhombeum subqua- 
dratumve, carpello omnino adnatum, pustulam minu- 
tissimam simulante. Seminula numerosa incipientia 
oblonga alba solum vidi. 

teretifolia. E. (cylindric-leaved) foliis teretibus acutis sparsis 

4. basi subsolutis, spicis secundis paucifloris. DeCand. 
Prod. 3. p. 401. 

Habitat 



264 Mr. Haworth's Description of the Genus Echeveria. 

Habitat in Mexico. *? . Flos omnino prioris. De 
Cand, 1. c. 

** Subherbaceae, floribus subcymosis luteis. 

ccespitosa. E. (dwarf yellow-flowered) foliis rosularibus an- 
5. guste linguiformibus, apice obcuneatis submucronatis, 
floribus cymosis. 

Cotyledon caespitosa. Nob. Misc. Nat. p. 180. 
A.D. 1803. — Cotyledon linguiformis. Ait. Hort. Kew. 
v. S. p. 109. — Sedum Cotyledon. Jacq. f. Eclog. 1. 
f. 17. — Cotyledon reflexum. Willd. Enum. Suppl. 
p. 24. — Echeveria caespitosa. DeCand. Prod. v. 3. 
p. 401. 

Habitat in California. 

Floret Jul. Aug. G. H. 11. s. 1? . 

P.S. I avail myself of the present opportunity of correcting 
the following errors, which time alone has enabled me to 
ascertain. 

1. Mesembr. deflexum, |3. Revis. PI. Succ. p. 140, is the 
same as M. imbrica?is, p. 139, and the last is a good and most 
abundant-flowering species. 

2. M. leptaleon is the young state only of M. retroflexum^ I.e. 

3. M.Jlexile is the young state only of M. polyphyllum, 1. c. 

4. And M. torquatum is a casual state only of M.Jloribun- 
dum. Revis. PI. Succ. p. 187. 

DeCandolle in vol. 3. p. 416 of his Prodromus, just published, 
says of Mesembryanthema : " Species plerseque hortenses ex 
cl. Haworth, &c. — sed forsan plures ut merae varietates ha- 
bendae." 

But all the new species which I have published, I w T as well 
and sufficiently assured, were raised from wild African, or 
Australasian seeds, except the following only, whose origin I 
cannot trace further than I have printed. M.Jiciforme; 
M. hybridum; M. nobile ; M. mustellinum ; M. bigibberatum : 
M. cruciatum; M. Salmii; M. cultratum; M. coruscans; 
M. procumbens ; M. variabile; M. mucroniferum ; M. loratum, 
and M. hispifolium. And even seven of the above I received 
from His Highness the Prince de Salm Dyck, whose genuine 
origin I believe he can point out. 

In my last communication Phil. Mag. and Annals, N.S., vol. 
iii. p. 184, 1. 15, for Crassidam undosam, read Crassulam un- 
datam. 



XLVII. An 



[ 265 ] 

XLVII. An Account of the Formation of Alcoatcs, Definite 
Compounds of Salts and Alcohol analogous to the Hydrates. 
By Thomas Graham, Esq. M.A. F.R.S.E.* 

TN determining the solubility of salts and other bodies in 
*■ alcohol, it is desirable to operate with a spirit wholly free 
from water. But anhydrous or absolute alcohol is formed 
with difficulty, even by the most improved process— that of 
Richter. In rectifying alcohol from chloride of calcium, as 
recommended by Richter, I have never obtained it under the 
specific gravity 0*798 at the temperature of 60°, by a single 
distillation ; but upon rectifying this product again from new 
chloride of calcium, I generally succeeded in reducing it to 
0*796, which is the specific gravity of the standard alcohol of 
that chemist. The following experiment illustrates this pro- 
cess. 

Four measures of alcohol of the specific gravity 0*826 were 
poured into a retort, and a quantity of well-dried chloride of 
calcium, amounting to three-fourths of the weight of the al- 
cohol, gradually added with occasional agitation. Much of 
the salt was dissolved with the evolution of heat ; and the com- 
bination was promoted by boiling the whole for a few minutes, 
the vapour being condensed in the neck of the retort, and re- 
turned to the solution. A receiver was then adjusted to the 
mouth of the retort, and the distillation conducted so slowly 
that the alcohol was condensed entirely in the neck of the re- 
tort, and fell drop by drop into the receiver, — nearly two se- 
conds elapsing between the fall of each drop. The first measure 
of alcohol which came over was of the specific gravity 0*800, 
at 60° ; the second measure, 0*798 ; and the third measure, 
0*801 : the distillation was then discontinued. These three 
measures were mixed together, and subjected to a second dis- 
tillation, which was conducted in the same manner ; and two 
measures of alcohol obtained of the specific gravity 0*796. It 
was found that further rectification did not reduce the spe- 
cific weight of the alcohol below 0*796. From the analysis 
of alcohol by Saussure, and the determination of the specific 
weight of its vapour by Gay-Lussac, there can be little doubt 
that the alcohol thus obtained is perfectly anhydrous. It is 
true that such alcohol still contains oxygen and hydrogen to 
the amount of an atomic proportion of water ; but this propor- 
tion of oxygen and hydrogen is essential to the constitution of 
alcohol, — the partial abstraction of it converting alcohol into 

* From the Transactions of the Royal Society of Edinburgh : this paper 
was read before the Society on the 17th of December 1827- 

New Series. Vol.4. No. 22. Oct. 1828. 2 M aether, 



266 Mr. Graham's Account of the Formation of Alcoates. 

aether, and its total abstraction converting alcohol into olefiant 
gas ; while the supposition that the oxygen and hydrogen exist 
in the state of water, is altogether gratuitous. 

The process of Richter is exceedingly tedious, from the 
necessity of conducting it so slowly, and the waste of alcohol 
is considerable. I tried newly burnt quicklime instead of 
chloride of calcium, and distilled by the heat of a saline water- 
bath. If it is merely our object to obtain alcohol perfectly 
free from water^ no process could be more effectual. The 
product was of the specific gravity 0*794 ; but it contained a 
trace of aether, to which the extraordinary lowness of its spe- 
cific gravity is attributable ; and had an empyreumatic odour, 
notwithstanding the moderate temperature at which the distil- 
lation was conducted. This likewise is a very slow process. 

The process which I preferred is founded on the principle 
of Mr. Leslie's frigorific apparatus. The alcohol is concen- 
trated by being placed under the receiver of an air-pump, with 
quicklime. A large shallow basin is covered to a small depth 
with recently burnt lime in coarse powder, and a smaller basin 
containing three or four ounces of commercial alcohol is made 
to rest upon the lime : the whole is placed upon the plate 
of an air-pump, and covered over by a low receiver. Ex- 
haustion is continued till the alcohol evinces signs of ebulli- 
tion, but no further. Of the mingled vapours of alcohol and 
water which now fill the receiver, the quicklime is capable of 
combining with the aqueous vapour only, which is therefore 
quickly withdrawn, while the alcohol -vapour is unaffected. 
But as water, unless it has an atmosphere of its own vapour 
above it, cannot remain in the alcohol, more aqueous vapour 
rises. This vapour is likewise absorbed, and the process goes 
on till the whole water in the alcohol is withdrawn. Several 
days are always required for this purpose, and in winter a 
longer time than in summer. The following cases exhibit the 
rate, according to which the water is withdrawn. The first 
experiment was made in summer. Four ounces of alcohol of 
the specific gravity 0*827 were concentrated. The specific 
gravity was taken every twenty-four hours, and the following 
series of results obtained : 

0*827 

0*817 

0*808 

0*802 

0*798 

0*796 
In this case the whole water was withdrawn in five days, but 

occasionally 



Mr. Graham's Account of the Formation qfAlcoates. 267 

occasionally a period somewhat longer is required, although 
it rarely exceeds a week. In winter the alcohol generally re- 
quires to be exposed to the lime for a day or two longer than 
in summer. The following rate of concentration was observed 
in one case in winter, the quantity of alcohol and other cir- 
cumstances being the same as in the former experiment : 

0-825 

0*817 

0-809 

0-804 

0*799 

0-797 

0-796 
Quicklime, as a porous substance, appears to be capable of 
condensing a small portion of alcohol- vapour. It is therefore 
improper to use it in great excess. In one case, in which 
three pounds of quicklime were employed with four ounces of 
alcohol, about one-sixth of the alcohol was lost from this ab- 
sorption. The quicklime should never exceed three times the 
weight of the alcohol, otherwise the quantity of alcohol ab- 
sorbed becomes sensible. It should be spread over as great 
a surface within the receiver as possible. 

In Richter's process it is improper to operate upon more 
than a few ounces of alcohol at a time ; as when a large quan- 
tity of materials is introduced into the retort, the heat neces- 
sary to disengage the alcohol in the centre of the mass inevi- 
tably expels the water left in the chloride of lime, at the points 
where it is more exposed to the heat. In the air-pump also, 
only a few ounces can in general be concentrated at a time. 
But in a tall receiver, two or three shallow basins of quick- 
lime can be supported at a little height above each other, each 
of them containing a small basin of alcohol resting in it. Or 
the process might be conducted with facility on the large scale, 
by means of a tight box of any size, furnished with numerous 
shelves, which might be covered with quicklime in powder, 
and support a large number of basins of alcohol. The box 
might be sufficiently exhausted of air by means of a syringe, 
for it is not necessary that the exhaustion be nearly complete ; 
and indeed more inconvenience is to be apprehended from a 
complete than from an imperfect exhaustion. After produ- 
cing the exhaustion, no further attention would be necessary; 
and upon opening the box at the expiration of a week or ten 
days, the alcohol would be found anhydrous. It is evident 
that absolute alcohol, procured by this process, could be sold 
at a price but little exceeding its original cost. It would more- 
over be of much greater value for the purposes for which it is 

2 M 2 employed 



268 Mr. Graham's Account of the Format ion of Alcoatcs. 

employed in the arts and in medicine. I believe, however, that, 
by the excise laws as they at present exist, no rectifier of 
spirits is permitted to concentrate alcohol beyond a certain 
strength. Licensed apothecaries alone are allowed to prepare 
and sell absolute alcohol *. 

Alcohol may be concentrated in a close vessel with quick- 
lime, without exhausting; but the process goes on much more 
slowly, at least at the temperature of the air. The experiment 
was tried at a high temperature, by heating in a water-bath a 
large bottle with a very wide mouth, containing a quantity of 
alcohol at the bottom, and quicklime suspended over it in a 
linen-bag. When the water-bath attained the temperature of 
150°, the bottle was corked, and the bath prevented from be- 
coming hotter. Much of the lime was very quickly converted 
into hydrate, and the alcohol considerably concentrated. But 
the process is troublesome, and much inferior to that in which 
the air-pump is employed. 

In the place of quicklime, sulphuric acid cannot be sub- 
stituted in the foregoing process as an absorbing liquid, from 
a remarkable property which it possesses. It is capable of 
absorbing the vapour of absolute alcohol, in the same manner 
as it absorbs the vapour of water. I was led to make this ob- 
servation from a consideration of the phaenomena which at- 
tend the mixing of alcohol and sulphuric acid. Nearly as 
much heat is evolved as if water had been added to the acid, 
even although absolute alcohol be employed. Alcohol is also 
retained by the acid when heated to 500° or 600°, or at a tem- 
perature when the alcohol would be decidedly in the state of 
vapour, — which indicates the possibility of the same relation 
between sulphuric acid and alcohol vapour, that subsists be- 
tween water and those gases which it detains in the liquid 
state, such as ammoniacal gas, when they would naturally as- 
sume the elastic form. But besides merely detaining such 
gases, water can condense and absorb them. Sulphuric acid, 
besides merely detaining alcohol-vapour, might therefore con- 
dense and absorb it. 

As alcohol, like water, occasions cold by its evaporation, it 
may be substituted for water in Mr. Leslie's frigorific appa- 

* Care should be taken that the temperature be nearly equable during 
the experiment ; otherwise, when the atmosphere becomes cold, a conden- 
sation of alcohol- vapour takes place upon the cooled bell-glass, which runs 
down upon the plate of the pump. The experiment, therefore, should not be 
performed in a room with a fire, or near a window, but in a dark closet or 
press. From the manner in which I performed the experiment, this con- 
densation had never been experienced by myself ; but Dr. Duncan junior 
observed it, on repeating the process. 

ratus, 



Mr. Graham's Account of the Formation ofAlcoates. 269 

ratus, sulphuric acid being retained as the absorbing liquid. 
In circumstances precisely similar, it was found that a ther- 
mometer, the bulb of which was covered with cotton, fell to 
7° when moistened with water, but when moistened with ab- 
solute alcohol its temperature fell to — 24*°. Continuance of 
the pumping during the experiment, as is done in the case of 
aether, had a prejudicial effect. But alcohol diluted with a 
third of water was found to have as great a cooling power as 
absolute alcohol. The advantage to be derived from the great 
volatility of alcohol appears to be counterbalanced in part by 
the small latent heat of its vapour. Probably a mixture of 
alcohol and water, in certain proportions, would produce the 
greatest degree of cold attainable by this process. Sulphuric 
acid loses its power to absorb alcohol-vapour by being diluted 
with water. When impregnated with alcohol -vapour, the 
acid becomes of a pink colour ; but no appretiable quantity of 
gas is emitted at the temperature of the atmosphere, even in 
the vacuum of an air-pump. 

From one experiment, water appears to have the power to 
induce the evaporation of alcohol by absorbing its vapour, as 
sulphuric acid does, but much more feebly. Two cups, one 
containing alcohol and the other pure water, were inclosed 
together in a tin-canister which was nearly air-tight, and set 
aside in a quiet place for six weeks. The cups were not in 
contact, but a little apart from each other. At the expiration 
of that period it was found, on opening the canister, that the 
cup which originally contained pure water, now contained a 
mixture of water and alcohol, while the alcohol remaining in 
the other cup was of diminished strength. Professor Leslie 
informs me, that he performed a similar experiment a consi- 
derable time ago, although no account of it was published. But 
the absorption of alcohol-vapour by water is so feeble as not 
to occasion a sensible reduction of temperature in the alcohol. 

Chloride of calcium is disqualified as an absorbent of aqueous 
vapour in the purification of alcohol, for the same reason as 
sulphuric acid. I find that chloride of calcium absorbs the 
vapour of absolute alcohol, and runs into a liquid, or it deli- 
quesces in alcohol- vapour. A small quantity of this substance 
was suspended in a little capsule, at the height of two inches 
above a quantity of absolute alcohol, in a close vessel. In the 
course of twenty-four hours it was entirely resolved into a li- 
quid, just as if it had been suspended over water. The liquid 
proved to be a solution of chloride of calcium in absolute al- 
cohol. The experiment was frequently repeated. As salts 
which deliquesce from the absorption of aqueous vapour are 
always capable of forming hydrates, I was led from the ob- 
servation 



270 Mr. Graham's Account of the Formation of Alcoates. 

servation of this fact to attempt the formation of analogous 
compounds of alcohol and salts, — to which I now proceed. 

These solid compounds of salts and alcohol, which are de- 
finite and imperfectly crystallizable, may be denominated Alco- 
ates, — a designation which is not unexceptionable, but ap- 
peared to me preferable to the name Vinates, as there is a 
sulpho-vinous acid ; or to any other name that might have been 
imposed upon them. 

The alcoates which I succeeded in forming are not nu- 
merous. They were formed simply by dissolving the salts, 
previously rendered anhydrous, in absolute alcohol, with the 
assistance of heat. On cooling, the alcoates were deposited 
in the solid state. The crystallization was generally confused, 
but in some cases crystalline forms appeared of a singular de- 
scription. The crystals are transparent, decidedly soft, and 
easily fusible by heat in their alcohol of crystallization, which 
is generally considerable, amounting in one instance to nearly 
three-fourths of the weight of the crystals. 

I. Alcoate of Chloride of Calcium. 

Pure muriate of lime was dried as much as possible on a 
sand-bath of the temperature of 600° or 700°, and then slowly 
heated to redness, and retained for some time at that tempera- 
ture. The dry chloride of calcium thus obtained dissolves in 
absolute alcohol at 60° with great facility, and with the pro- 
duction of much heat, sometimes occasioning the boiling of the 
solution. The quantity of chloride taken up increases with the 
temperature; and at 173°, the boiling point of alcohol, 10 parts 
alcohol dissolve 7 parts chloride of calcium. This solution is 
thick and viscid, but perfectly transparent, provided the chlo- 
ride be pure. It boils at 195°, alcoholic as well as aqueous 
solutions boiling at higher temperatures than the pure liquids. 
The viscidity of the solution of chloride of calcium increases 
greatly as it cools. Bright crystalline stars soon appear on the 
surface and on the sides of the vessel, which have been moist- 
ened by the solution. The solution, however strong, never 
crystallizes instantaneously, but gradually, in thin transparent 
and colourless plates, the forms of which cannot be made out, 
except on the surface of the solution and sides of the vessel. — 
To obtain the alcoate in a state of absolute purity, it is neces- 
sary to form a solution so weak, that, while hot, it will pass 
through thin filtering paper; and afterwards to concentrate 
the filtered solution by heat. A solution of one part chloride 
of calcium in five parts alcohol passes through the filter. It 
is remarkable that the most distinct crystalline forms are not 

obtained 



Mr. Graham's Account of the Formation of Alcoates. 271 

obtained from the slow crystallization of comparatively weak 
solutions ; but in solutions which have been fully saturated, or 
nearly so, at the boiling temperature. In the" former case, the 
crystalline plates are large, but confused, and nothing but an- 
gles can be made out ; while in the latter, the forms, under 
which the plates appear on the surface of the solution, and to 
the greater advantage, on the sides of the vessel, are generally 
distinct. These plates are always small, often beautiful, and 
delicately striated ; and they always present the form of isos- 
celes triangles. In general, four of these triangular figures are 
grouped with their apices together ; and if similar, they form 
a square. But, as more frequently happens, the opposite pairs 
of triangles only are similar ; and the figure presented is a 
rectangular parallelogram, divided by two diagonal lines into 
four triangles. The resolution of the rectangle into triangular 
figures is rendered perceptible by the discontinuance of the 
striae, and the formation of clear diagonal lines, which have 
a beautiful effect. These crystals cannot be removed from 
the phial in which they are formed without injury, from their 
softness. Exposed to the air, they speedily deliquesce from the 
absorption of hygrometric moisture. The heat of the hand is 
sufficient to melt them. The whole of the alcohol is expelled 
by a heat amounting to 250°, and pure chloride of calcium 
remains, which emits nothing else upon being heated to red- 
ness. 

A quantity of this alcoate was dried, first by strong pressure 
between many folds of linen, and then by pressure between 
folds of blotting paper. The alcoate, carefully dried in this 
way, had a white appearance much resembling bleached wax, 
and was soft, but without tenacity. 

Ten grains were heated in a glass capsule, till the whole of 
the alcohol was driven off. There remained 4*1 grains chlo- 
ride of calcium. The atomic weight of chloride of calcium is 
7, and that of alcohol 2*875. In the alcoate, 4*1 grains chlo- 
ride of calcium were combined with 5*9 grains alcohol. 

4-1: 5-9:: 7: 10-0731. 

In a second analysis, in which 20 grains of alcoate were em- 
ployed, the result was precisely similar, as 8*2 grains chloride 
of calcium remained, which is just double what was obtained 
in the previous case from half the quantity of alcoate. If this 
alcoate should be considered a compound of one equivalent 
proportion of chloride of calcium, and three and a half pro- 
portions alcohol, the alcohol would amount to 10*0625, which 
approaches very nearly to the experimental results. But it 

would 



272 Mr. Addison's Remarks on the Influence of Terrestrial 

would be better to express the composition of the alcoate thus 

Two atoms chloride of calcium 14* 

Seven atoms alcohol 20*125 



34-125 
In the solution of chloride of calcium, no crystallization 
takes place at the temperature of 50°, when the alcohol ex- 
ceeds the proportion of 10 parts to 4 parts of the dry salt. 
But the solution crystallizes readily when further concen- 
trated. A solution saturated at 170°, and which consisted of 
10 parts alcohol and 7 parts chloride of calcium, or nearly 
the atomic proportions of the alcoate, crystallized slowly upon 
cooling, forming crystals upon the surface of the liquid and 
sides of the phial, of great regularity and beauty. The whole 
crystallized during a cold night, leaving no mother-liquor 
whatever. 

The injurious effect of the presence of water, in the forma- 
tion of this alcoate, was evident in alcohol of the specific gra- 
vity 0*798, in which the contaminating water did not amount 
to 1 per cent. A solution of chloride of calcium in alcohol of 
this strength did not crystallize readily, and the crystals even- 
tually deposited were small and ill-formed. Chloride of cal- 
cium does not crystallize at all in alcohol of the specific gra- 
vity 0*827. The same inconvenience arises from employing 
chloride of calcium containing a little water. 

Although the alcoate of chloride of calcium in a state of 
purity is entirely decomposed at a temperature not exceeding 
250°, yet, when water ! . present, alcohol can be retained by 
the chloride of calcium at a much higher temperature. Thus 
I repeatedly found, that chloride of calcium, from which al- 
cohol had been rectified, and which afterwards had been 
washed out of the retort by water, gave indications of the pre- 
sence of alcohol, after being exposed on the sand-bath to a 
heat of 400° or 500° for several hours. Transferred in a 
crucible to the fire, after it ceased to lose weight on the sand 
bath, alcohol-vapour was emitted, which took fire and burned. 
[To be continued.] 



XLVIII. Remarks on the Influence of Terrestrial Radiation in 
determining the Site of Malaria. By Wm. Addison*. 

THHE diseases arising from atmospheric impregnations have 
-■• long formed an important topic of inquiry among medical 
men, and are generally supposed to have an origin from some 



Communicated by the Author. 

subtile 



Radiation in determining the Site of Malaria* 273 

subtile poison, prevalent only in certain places, or over very 
circumscribed situations. Upon considering the various cir- 
cumstances under which these diseases are produced, and the 
impossibility of any poison dispersed through the air from the 
ground becoming partial in its operation, or always confined 
to any particular district (when every wind must waft it away 
from the spot of its emanation), unless some adventitious cir- 
cumstance influences its operations, — I am induced not to sub- 
scribe to the doctrine which teaches that they take place from 
a specific or peculiar and locally acting effluvium. On the 
contrar}', I think we shall find that most of the ordinary at- 
mospheric impregnations will produce the diseases of Malaria, 
when under certain peculiar circumstances they are liberated 
from their combinations; diseases which will, no doubt, be 
violent or not, according to the quantity or quality of the mat- 
ters developed. 

The atmosphere, as is well known, retains every where 
mingled with it variable proportions of aqueous vapour, mixed 
probably with various effluvia arising from the action of the sun 
upon the many substances on the surface of the earth. During a 
bright day, therefore, the air over those portions of the ground 
subjected to its influence becomes saturated with vapour, and 
any reduction of temperature by radiation will always be ac- 
companied by the deposition of moisture and the precipitation 
of a portion of those subtile matters drawn up by the agency 
of heat; whereas any diminution of sensible caloric, which 
may ensue from a rush of cold air, may not be accompanied 
with the same effects : for it very often happens that such cur- 
rents have not nearly attained their maximum point with re- 
spect to vapour, and therefore none of these things happen ; 
or if they do, the deposits occur in the form of rain, far less 
prejudicial than those chilly fogs produced by the radiation of 
caloric from the earth. 

When we think of the important process of radiation, the 
effects of which have excited the attention of philosophers, 
especially diose connected with horticultural pursuits, it is ex- 
traordinary that it should wholly have escaped them to pursue 
their investigations into this curious subject, with reference to 
the momentous matter of local salubrity ; for little doubt re- 
mains upon my mind, that a well conducted series of experi- 
ments instituted to discover the phaenomena resulting from the 
radiation of heat into the heavens, in different situations and 
over various surfaces and soils in several places at the same 
time, would discover to us an important field well worthy of 
research as connected with the health of mankind. 

I have already endeavoured to draw the attention of those 
New Series. Vol. 4. No. 22. Oct. 1828. 2 N who 



274 Mr. Addison's Remarks on the Influence of Terrestrial 

who may possess opportunity and the means of entering into 
this interesting branch of inquiry, towards the benefits their 
labours are likely to confer upon us in a medical point of view*. 
I have shown that all those situations where the radiation of 
caloric goes on with rapidity, are occasionally, if not at all times, 
extremely unhealthy; while others, where this process is dimi- 
nished, are on the contrary much less obnoxious to disease. 
I have shown that debilitated constitutions are invariably found 
to regain the tone and vigour of health much more perfectly 
and more quickly in places little influenced by radiation or 
removed from the sphere of its effects, than in others exposed 
to the depositions which it causes from the air; and I have 
endeavoured to confirm these observations, by pointing out that 
in the radiation of caloric may be found the cause of the acti- 
vity of those exhalations with which the sun, in tropical cli- 
mates especially, saturates the air : in fine, that in this impor- 
tant process one of the principal causes of malaria will be 
found. 

I shall here offer a few more facts in support of the views 
I have taken. And as nothing has tended more to confirm me 
in them than the perusal of Dr. Macculloch's Essay on the 
Production and Propagation of Malaria, I shall proceed to 
the consideration of some of the passages in that publication. 

" The careful observer will often perceive," says the Doctor, 
"that there are certain determinate places without any marshes, 
where fevers are almost annually prevalent; while other places 
in the vicinity are almost wholly or nearly exempt. A proof 
of this may be drawn from the fact that some localities are 
known to be unhealthy as compared with other neighbouring 
places. 

" Thus it is the vulgar remark, that in certain houses or 
places a family is rarely without some sickness ; or, to use the 
strong but coarse language in which it is generally stated, * that 
the apothecary is never out of the house.' It is almost equally 
familiar, that families which before had been healthy, have be- 
come the reverse on changing houses or situations ; as in the 
opposite cases, that they have recovered health by change of 
residence. Of such facts as these there is no observer who 
must not be able to recollect numerous examples." Again, 
" If a gravelly soil is healthy, it is because its easy drainage 
prevents the growth of that particular vegetation which is the 
cause of malaria ; and if a clayey soil is the reverse, it is be- 
cause by lodging superficial water it generates, however par- 

* Vide the last section of" A Dissertation on the Nature and Properties 
o( the Malvern Water," &c. &c. 

tially, 



Radiation in determining the Site of Malaria, 275 

tially, those marshy or undrained spots, or wet woods or moist 
meadows, which are the sources of this poison, and conse- 
quently of the various diseases confounded under the vague 
term of unhealthiness." — Essay, pp. 19 & 21. 

Now, upon this latter passage I may remark, that as water 
is one of the best radiators of caloric, so all wet, low, and 
marshy places will be found the most affected by it ; and it will 
follow that any soil whose mechanical texture is such as to 
allow the water to permeate through it, or to drain off, at the 
same time that other circumstances combine to arrest the dissi- 
pation of heat by radiation, that soil will be found much more 
salubrious than one retentive of moisture, and particularly if 
the surface of this latter is covered with low herbage or grass, 
which is in itself an excellent promoter of terrestrial radiation. 

" That woocls and jungles in hot countries give origin to 
miasmata of the worst kind is well known to all medical men ; 
but some doubt may be entertained as to their insalubrity in 
Europe." — " Dr. Macculloch thinks there is strong reason to 
believe that close and wet woods generate malaria in this as 
well as in the warmer countries of Europe. Certain woody 
districts in Sussex and Kent produce both intermittent and 
remittent fevers, — at least there is no other assignable cause. 
The same may be said of some parts of Hampshire and Essex ; 
as about Epping Forest, for example." — " On the other hand, 
we have positive testimony that lands which were healthy when 
covered with wood, have become extremely unhealthy when 
cleared and cultivated." 

The thick foliage, as I have elsewhere shown, of the trees 
composing most of the intertropical forests, and even of some 
of those also in this country, by obstructing the rays of the 
sun, preserve in their immediate vicinity a greater degree of 
stillness and a lower temperature than that attained by the 
atmosphere over the contiguous grounds; whence the heated 
air coming to slowly circulate among the branches of the trees 
of these forests, becomes cooled, and its vapours developed; and 
it is these which occasion the diseases of malaria. — "Yet it 
requires much circumspection," says the Doctor, "in deciding 
upon the propriety of clearing these grounds with the view of 
rendering them more salubrious." — And why ? Because trees 
naturally tend to obstruct the force of radiation ; and, if planted 
on a good radiating surface, not so close together as entirely 
to obstruct the genial influence of moderate warmth from the 
sun's rays, or to prevent the free circulation of the air, will 
prove a valuable defence against the appearance of malaria, 
by counteracting that unequal distribution of temperature 

2 N 2 which, 



276 Mr. Addison's Remarks on the bifluence of Terrestrial 

which, / believe, develops its existence in the air : whereas, if 
these are cut down and the ground cleared, a good radiating 
surface becomes immediately exposed, and the dissipation of 
caloric with its accompanying effects directly ensues. — " A 
portion of grass-plat," says Mr. Daniell in his Meteorological 
Essays, " under the protection of a tree or hedge will generally 
be found on a clear night to be eight or ten degrees warmer 
than surrounding unsheltered parts ; and it is well known to 
gardeners that less dew and frost are to be found in such si- 
tuations than in those which are freely exposed." — Dr. Mac- 
culloch in noticing the comparative healthiness of ancient and 
modern Rome, thought it not unimportant to notice what 
Theophrastus has stated with regard to the plain of Latium, 
which this historian says was covered with laurel and myrtle- 
trees of such a size as to be used in ship-building ; and this 
remark, if terrestrial radiation has any thing to do with the de- 
velopment of malaria, is not so fanciful as one of his reviewers 
seems to imagine it*. Again, If terrestrial radiation is the cause 
of the deleterious influence of those effluvia existing in the at- 
mosphere, we are no longer surprised at finding rice-grounds, 
which are kept in a constant state of wet or moisture during 
the growth of the plants, prolific in the diseases which ma- 
laria occasions. 

" Dr. Macculloch is convinced that the minute marshy 
or swampy spots which occur in thousands of low situations, 
whether on commons, near woods by road sides, or in innu- 
merable other places where they hardly ever attract notice, — 
are productive of malaria ; though their limited range of action 
generally renders their power insensible, unless when houses 
happen to be erected in their vicinity." — " In how far meadows 
which cannot be called marshy are capable of producing ma- 
laria, is an intricate and entangled question. It appears cer- 
tain, however, that there are many tracts of meadow or of al- 
luvial land not marshy, and often not intersected by ditches, 
at least in a conspicuous manner, which are the sources of 
malaria all over Europe." Essay, p. 69. — " Such is the case 
with all the alluvial tracts at the entrances and sometimes at 
the exits of the lakes of Switzerland and elsewhere ; and in 
places innumerable where there is no proper marsh, nor even 
an approach to such a character, but where the prevalent dis- 
eases must be owing to malaria." — " Volney, while travelling 
in America, has averred that every valley in the country which 
he visited produced the fevers of malaria, enumerating among 
the sources of this poison not only marshes and wood, but 

* Medico-Chirurgical Review, January 1828. 

rivers, 



Radiation in determining the Site of Malaria, 277 

rivers, millponds, &c." — " The meadow lands about Fontain- 
bleau, at the junction of the Yonne and the Seine, are noto- 
rious for the Jievre du pays; so injurious are they, that few 
escape intermittents or remittents over a considerable tract." 
If some great portions of the meadow-land in England have 
been recovered by drainage from a state of marsh, and are 
now as dry as the ordinary low-lands of plains and valleys ; 
and if these localities still produce malaria and its conse- 
quences, — it is another point of evidence against the salubrity 
of meadows generally. " It is a rooted opinion in England, 
that there can be no malaria on the banks of a running stream ; 
and as far as mountain-torrents are concerned, this is probably 
true : but where rivers slowly meander through low grounds, 
we must not trust to the mere motion of the water." — " For 
whatever persons may still think as to rivers in general in our 
own country, there is no doubt that such streams as the Ouse, 
the Lee, and all others flowing with difficulty through fertile 
meadows, and with a flat vegetable margin, are productive of 
malaria." 

But not to occupy more than necessary the time of the reader 
by quoting further from Dr. Macculloch's Essay, I shall only 
observe that this author has found small streams bordered 
by thin and grassy margins; tranquil and stagnant waters, 
especially in hot countries ; and ponds occupying but a small 
space, — to be productive of f evening mists,' the results of which 
are autumnal and intermittent fevers." And is not the ter- 
restrial radiation of caloric, I would here ask, the cause of those 
evening mists which favour the attacks of these disorders ? In- 
deed it is remarkable to find that every locality pointed out 
by the Doctor as productive of malaria, will be found to possess 
one or other of those circumstances which promote the dissi- 
pation of heat from the ground. It has long been known that 
water and a grassy surface are excellent radiators of caloric ; 
and the effects of this process — fogs, damps and dew — were ob- 
served long before the cause of them was properly understood. 
" A valley," says Mr. Daniell*, "is more liable to the effects 
of radiation, than the tops or sides of hills ; and it is a well- 
known fact that dew and hoar-frost are always more abundant 
in the former than in the latter situations. The influence of high 
hills is, however, often prejudicial to the valleys at their feet ; tor 
the condensed and moist air rolls down their sides, and lodges 
at the bottom: these, therefore, are protected from the chill, while 
a double portion falls upon what many are apt to consider the 
more sheltered situation. It is a very old remark, that the in- 
jurious effects of cold occur chiefly in hollow places, and that 

* Meteorological Essays and Observations. 

frosts 



278 Mr. Children's Abstract of the Characters of 

frosts are less severe upon hills than upon the neighbouring 
plains : and it is consistent with my own observations, that the 
leaves of the vine, the walnut-tree, and the succulent shoots of 
Dahlias and potatoes, are often destroyed by frosts in the shel- 
tered valleys, on nights when they are perfectly untouched upon 
the surrounding eminences. ,, The diminution of temperature 
which is produced upon the surface of radiating bodies during 
the night is communicated by slow degrees to the surrounding 
atmosphere ; and if the process goes on for any considerable 
period, moisture and probably other matters are not only de- 
posited upon them, but are precipitated in the air itself, af- 
fecting more or less the feelings of every one within its range, 
but particularly the weak or unhealthy. 
[To be continued.] 



XLIX. An Abstract of the Characters of Ochsenheimer's 
Genera of the Lepidoptera of Europe; with a List of the 
Species of each Genus, and Reference to one or more of their 
respective Icones. By J. G. Children, F.R.S. L. 8? E. 
KL.S. $c* 
TN SamouehVs Entomologist's Useful Companion, as well 
* as in several other works of deserved reputation, the names 
of the Genera established by Ochsenheimer, in his Schmet- 
terlinge von Europa, are frequently quoted, but the characters 
on which they are founded wholly omitted, so that they can only 
be inferred from a laborious comparison of those of their re- 
spective types, — a task few persons will be disposed to submit 
to, in order to clear up an occasional doubt, as to what genus 
such or such an insect is to be referred. This inconvenience 
is attributable to the want of an English edition of Ochsen- 
heimer's work ; and in some measure to lessen it, the following 
translation of his Family and Generic Characters is offered to 
the British student. 

Ochsenheimer died in 1822, leaving his work incomplete, 
only four volumes having been published in his life-time, the last 
of which appeared in 1816, and consists chiefly of an im- 
proved sketch of his arrangementof the Europaean Lepidoptera 
from the first genus to the eighty-seventh. Before his death, 
however, only the first forty-three genera were published in 
detail, with the characters and descriptions of their respective 
species ; these occupy the first three volumes, the last of which 
terminates with the genus Eyprepia ; for the fourth contains, 
besides the sketch of the arrangement, only notes concerning 

* Communicated by the Author. 

some 



Ochsenheimer's Genera of the Lepidoptera of Europe. 279 

some of the species published in the former volumes. The 
work is continued by M. Frederick Treitschke, and the spe- 
cific descriptions are completed to the hundred-and-sixth genus 
inclusive ; and M. Treitschke has also given a further sketch of 
the arrangement, including ten additional genera consisting of 
the Phalcence Pyralides of Linnaeus, the specific descriptions 
of which are not yet published*. More therefore still re- 
mains to be done, and we wait anxiously for the completion of 
the work. In the mean time we lay the present abstract be- 
fore the reader ; and should he entertain any doubts of the 
value of M.M. Ochsenheimer's and Treitschke' s labours, we 
refer him to the Introduction to Dr. Horsfield's Descriptive 
Catalogue of the Lepidopterous Insects contained in the Mu- 
seum of the East India Company, where he will find such 
ample testimony to their merit as cannot fail (unless he dis- 
regard the maxim " laudari a laudato") presently and effec- 
tually to remove them. 

1st Zfcws^.—PAPILIONES. 

Wings when at rest, erect. 

Antenna filiform, generally capitate, or terminated by a 

knob ; sometimes only slightly incrassate at the end. 
Flight, diurnal. 
Larva with sixteen legs; head globular, perfectly distinct 

from the body; motion indolent, and sluggish. 
Pupa angular. 
Metamorphosis generally naked, or not concealed by a web. 

Genus 1. MELITiEA, Fab. 

Melit^a, Fab. Syst. Glossat. 

Battus et Graphium, Scopoli. Introductio ad Hist. Nat. 

Nymphalis, Latr. Gen. Crust, et Ins. 

Papilio, Schrank. Faun, boi'c. 

Lemoniades, Hubn. 

Legs, first pair imperfect. 

Wings, roundish; upper surface of the anterior wings, red- 
dish-yellow with black maculae and dots, or blackish, 
with reddish-yellow maculae and dots ; under surface of 
the posterior wings with alternate orange-yellow, and 
yellowish-white cross bands with black spots; not sil- 
vered. 

Antennae, knob oval, compressed, obtuse. 

* The hist volume as yet published is the sixth, of which, Parts T. and II. 
appeared in the present year. 

Larva 



280 Mr. Children's Abstract of the Characters of 

Larva with seven or nine conical, fleshy protuberances, co- 
vered with short hairs, on each of the middle segments 
of the body, and two larger on the side of the throat. 

Pupa, anteriorly rather obtuse, hinder part usually with ele- 
vated points ; not suspended in any constant manner. 

Species. Icon. 

1. M. Maturna, Linn... Ernst, I. PI. XVII. f. 27. a.b. 

2. — Cynthia, Fab Ernst, I. PL XVII. f. 26. a— d. 

3. — Artemis, Fab Ernst, I. PL XVII. f. 28. a.b. 

4. — Cinxia, Linn Ernst, I. PL XIX. f. 32. a— f. 

5. — Didyma, Esp. ... Ernst, I. PL XVIII. f. 29. a— d. 

6. — Trivia, Hiibn. ... Ernst, I. PL LXI. Suppl. VII. 

f. 29. a— d. bis. 

7. — Phoebe, Hubn. ... Ernst, I. PL LXI. Suppl. VII. 

f. 28. a. b. bis. 

8. — Bictynna, Esp.... Ernst, I. PL LXII. Suppl. VIII. 

f.31. a— d. bis. 

9. — Athalia, Esp Ernst, I. PL XIX. f. 31. c. d. 

10. — Parthenia, Borkh. Hubn. Pap. Tab. 4.f.l9. 20.(fcem.) 

11. — Lucina, Linn Ernst, I. PL XVI. f. 25. a. b. 

Genus 2. ARGYNNIS, Fab. 

Argynnjs, Fab. Papilio, Schrank. 

Argyreus, Scop. Dryades, Hiibn. 

Nymphalis, Latr. 

Legs, four perfect, gressorial. 

Wings subdentate, upper surface generally reddish-brown with 
black spots ; under surface with silvery bands or spots. 

Antenna? capitate, knob compressed. 

Larva with six longitudinal rows of ramose spines, and two 
others, generally larger than the rest on the first seg- 
ment ; a broad, longitudinal, dorsal band, divided by a 
medial line. 

Pupa, suspended variously ; cavity of the neck, and the neck, 
with brilliant points. 

Species. Icon. 

1. A. Aphirape, Hubn. Hiibn. Pap. Tab. 5. f. 23. 24. 

(mas.) 25. (foem). 

2. — Selene, Fab Ernst, I. PL XVI. f. 23. a. b. 

3. — Euphrosyne, Linn. Ernst, I. PL XVI. f. 22. a. b. 

4. — Dia, Linn Ernst, I. PL XV. f. 21. a. b. 

5. A. Pales, 



Ochsenheimer's Genera of the Lepidoptera of Europe. 281 

Species. Icon. 

5. A. Pales, Hiibn Ernst, I. PL LX. SuppLVI. f. 21. 

a. b. c. d. bis, a. b. c. d. tert. 

6. — Hecate, Fab Ernst, I. PI. LIX. Suppl.V. f. 20. 

a — d. tert. 

7. — Ino, Hubn Ernst, I. PL XV. f. 20. c. 

8. — Daphne, Fab Ernst, I. PL XV. f. 20. a. b. 

9. — Frigga, Hubn. Hiibn. Pap.Tab. 9.f.49. 50.(foem.) 

10. — Thore, Hubn.... Hubn. Pap. Tab. 3. f. 571— 

573. 

11. — Amathusia, Fab. Ernst, I. PL LXXX. Suppl. II. 

PL I. f. 21. a. b. quart. 

12. — CharicIea,Schneid. Herbst, Pap. Tab. 272. f. 5. 6. 

13. — Freija, Schneid... Herbst, Pap. Tab. 272. f. 7—10. 

14. — Latonia, Linn. ... Hiibn. Pap. Tab. 11. f. 59. 60. 

(fcem.)Pl.CXX.f.613. var. 

15. — Niobe, Linn Ernst, I. PL XV. f. 19. a. b. c. 

16. — Adippe, Fab Ernst, I. PL XIII. f. 16. c— i. 

17. _ Aglaia, Linn Hiibn. Pap.Tab. 13.f.65.66.(fcem.) 

J 8. — Laodice, Fab. .... Hiibn. Pap.Tab. 13.f.67.68.(foem.) 

19. — Paphia, Linn. ... Ernst, I. PL XII. f. 15. a— f. 

20. — Pandora, Fab. ... Ernst, I. PL XII. f. 15. g. h. 

Genus 3. EUPLOEA, Fab. 

Battus, Scop. 
Danais, Latn 
Limnades, Hiibn. 

Legs, four perfect. 

Wings, anterior with the external margin rather curved ; co- 
lour reddish-yellow, margin black with white spots; a 
curved band of white spots towards the apex. 

Antennae oval, knob gradually incrassate. Head and breast 
black, with white spots. 

Larva, with sixteen feet; feet sub-spinous, spines simple. 

Pupa nearly cylindrical ; suspended freely. 

Species. Icon. 

I. E. Chrysippus, Linn.... Hiibn. Pap. Tab. 133. f. 678. 

679. (mas.) 
f The only European species of the genus. 



New Scries. Vol. 4. No. 22. Oct. 1828. 2 O Genus 



282 Mr. Children's Abstract of the Characters of 

Genus 4. VANESSA, Fab. 

Cynthia, Fab. Papilio, Schrank. 

Nymphalis, Latr. Hamad ryades, Hiibn. 

Battus et Graphium, Scop. 

Legs, four perfect, gressorial. 

Wings, exterior margin angular ; upper surface spotted ; un- 
der side with transverse bands ; bands usually blackish- 
brown or variegated. 

Antenna? capitate. 

Larva sub-lanate, with several longitudinal rows of stiff, bristly 
hairs, or spines. (The first segment naked, second and 
third with four, and the rest with six spines.) Head 
blackish, bifid ; in some species armed with ramose sub- 
obtuse spines. 

Pupa suspended vertically ; often externally with a brilliant 
gold or silver hue: head and dorsal segments mucro- 
nate ; dorsal ridge acuminate. 

Species. Icon. 

A. Wings slightly dentate. 

1. V. Cardui, Lnin Ernst, I. PI. VII. f. 7. a— g. 

2. — Atalanta, Linn. ... Ernst, I. PL VI. f. 6. a — i. 

B. Wings furcate. 

3. V. lo, Linn Ernst, I. PI. II. f. 2. a— f. 

4. — Antiopa, Linn Ernst, I. PL I. f. 1. a — h. 

5. — V. album, Fab. ... Ernst, I. PL LVI. Suppl. II. f. 5. 

a — d. bis. 

6. — Polychloros, Linn. Ernst, I. PL III. f. 3. a — i. 

7. — Xanthomelas, Illig. Ernst, I. PL LV. Suppl. I. f. 3. a. 

b. bis. 

8. — Urticce, Linn Ernst, I. PL IV. f. 4. a— h. 

9. — Triangulum, Fab. Ernst, I. PL V. f. 5. g. h. 

10. — C. album, Linn.... Ernst, I. PL V. f. 5. a— f. 

- F. album, Fab. -I Herbst Schm . Tab . 163 . f . ,. 2 . 
(var. C. album) ... J ' 

C. Posterior wings slightly acuminate. 

11. V. Prorsa, Linn Ernst, I. PL VIII. f. 8. a— e. 

12. — Levana, Linn Ernst, I. PL VIII. f. 9. a— f. 

Genus 5. LIMEN1TIS, Fab. 
Neptis, Fab. Papilio, Schrank. 

Nymphalis, Latr. Naiades, Hiibn. 

Battus et Graphium, Scop. 

Legs, anterior pair very small ; second and third perfect, 



gressorial. 



Wings, 



Ochsenheimer's Genera of the Lepidoptera of Europe. 283 

Wings, dentated, the anterior somewhat repand * ; upper sur- 
face black, or blueish-green ; under surface reddish- 
brown, or cinnamon colour ; body griseous. 

Antenna clavate. 

Larva variegated ; head with two elevated points ; body with 
two longitudinal rows of ramose spines. 

Pupa variously suspended ; head with two small elevations ; 
the dorsal larger, securiform. 

Species. Icon. 

1. L. Aceris, Fab Ernst, I. PI. II. Suppl. III. f. 

12. a—d. bis. 

2. — Lucilla, Fab Ernst, I. PI. X. f. 12. a. b. 

3. — Sibylla, Linn Ernst, I. PI. XI. f. 13. a— f. 

4. — Camilla, Fab Ernst, I. PI. XL f. 14. a. b. 

5. — Populi, Linn Ernst, I. PI. IX. f. 10. a—d. 

Genus 6. CHARAXES, Ochs. 

Paphia, Fab. Nymphalis, Latr. 

Legs, first pair imperfect. 

Wings, anterior elongated, angular; posterior dentate, the 

external margin bicaudate near the apex. 
Antenna? clavate. 
Larva smooth ; head with four horns ; body bicuspidate at 

the anal extremity. 
Pupa, nearly oval. 

Species. Icon. 

1. C. Jasius, Linn. Drury, Illustr. of Nat Hist. I. 

PL I. f. 1. 
f Only one European species. 

Genus 7. APATURA, Fab. 

Nymphalis, Latr. Maniola, Schrank. 

Argus, Scop. Potamides, Hiibn. 

Legs, first pair imperfect. 

Wings, somewhat repand, and dentate; colour changeable 

according to the direction of the light, between brown and 

purple ; posterior wings ocellated at the interior angle. 
Antennae clavate, knob sub-cylindrical, and rather slender. 
Larva similar to that of Char axes; but with faint yellow 

transverse bands : head smooth anteriorly, with two long, 

straight, obtuse, or bipartite horns. 

* Ausgeschweift, repandus, repand: cut into very slight sinuations, so 
as to run in a serpentine direction. — Kirby and Spence, iv. 297. 

2 O 2 Pupa 



284 Mr. Children's Abstract of the Characters of 

Pupa green, compressed : head bicuspidate ; suspended ver- 
tically by the posterior extremity. 

Species. Icon. 

1. A. Iris, Linn Ernst, I. PL XXXI. f. 62. a. b. 

2. — Ilia, Fab Ernst, I. PL XXXI. f. 62. c. d. 

(foem.) PI. XXXII. f. 64. e. 
f. (mas.) 

Genus 8. HIPPARCHIA, Fab. 

Nymphalis, Latr. Maniola, Schrank. 

Argus, Scop. Oreades, Hiibn. 

Legs, first pair less than half the size of the second and third. 

Wings, generally brownish, with the margin ocellated. 

Antenna? clavate ; knob flattened ; (often slightly curved.) 

Larva, anal extremity bicuspidate : head globular, anteriorly 
depressed; generally hairy, with dark-coloured longi- 
tudinal striae ; hairs whitish. 

Pupa short, anteriorly bicuspidate, points erect, small; sus- 
pended by the anal extremity. 

Metamorphosis, usually in the air, but some species change 
under ground. 

Species. Icon. 

A. 1. H. Proserpina, Fab. Ernst, I. PL XX. f. 33. a. b. 

2. — Hermione, Linn. Ernst, I. PL XX. f. 34. a. b. c, 

3. — Alcyone, Linn. Ernst, I. PL LXII. Suppl. VIII. 

f. 35. a. b. c. 

4. — Anthe, Hubn. Hiibn. Pap. Tab. 1 15. f. 589.590. 

(fcem.) 

5. __ Briseis, Linn.. Ernst, I. PL XXI. f. 36. a— d. 

6. — Semele, Linn. . Ernst, I. PL XXII. f. 38. a. b. c. 

7. — Hippolytus, Fab. Ernst, I. PL VIII. Suppl. III. 

f. 36. a. b. bis. 

8. — Arethusa, Fab. Ernst, I. PL XXII. f. 39. a. b. c. 

9. — Fidia, Linn... Ernst, I. PL XXI. f. 37. c d. 

10. — Allionia, Fab. Ernst, I. PL XXI. f. 37. a. b. 

11. — Statilimis,¥ab. Ernst, I. PL LXIII. Suppl. IX. 

f. 37. a. b. c. bis. 

12. — Phaedra, Linn. Ernst, I. PL XXIII. f. 40. a— e. 

13. — Bryce, Fab. ... Hubn. Pap. Tab. 33. f. 149. 150. 

(foem.) 

14. — Cordula, Fab. Hiibn. Pap. Tab. 29. f. 132. 133. 

(fcem.) 

15. — Actcea, Hiibn, Ernst, I. PL LXIII. Suppl. IX. 

f. 37. g. h. 



Ochsenheimer's Genera of the Lepidoptera of Europe. 285 

Species. Icon. 

16. H. Podarce, Ochs.* — — — — 

17. — Aello, Hubn. . Hiibn. Pap. Tab. 102. f. 51 9. 520. 

(mas). Tab. 31. f. 141. 142. 
(fcem.) 

18. — Norna,T\mnb. Hubn. Pap. Tab. 34. f. 152. 153. 

(mas.) Tab. 30. f. 142. (fcem.) 

19. — Tarpeia, Fab. Cram.Pap.Exot.Pl.CCCLXXV. 

E. F. 

20. — Bore, Fab Hiibn, Pap. Tab. 29. f. 134. (mas.) 

135. 136. (fcem.) 

B. 21. — Tithonus,Unn. Ernst, I. PI. XXVII. f. 53. a— e. 

22. — Ida, Fab Ernst, I. Pl.V. Suppl. III.f.53.h. 

23. — Pasiph'de, Fab. Ernst, I. PL LXV1. Suppl. XII. 

f. 53. a. b. bis. 

24. — Clymene, Fab. Ernst, I. PL V. Suppl. III. f. 50. 

a. b. tert. 

25. — Roxelana,Fab. Cram. Pap. Exot. PL CLXI. 

fig. C. D. E. F. 

26. — Janira, Linn.. Ernst, I. PL XXVIII. f. 54. a— h. 

27. — Eudora, Fab. . Ernst, I. PL XXVIII. f. 55. a. b. 

C. 28. - Hweranthus, 1 ^ L pL xxvn f ^ ^ 

29. — Dejanira,L\nn. Ernst, I. PL XXV. f. 48. a. b. 

30. — Hiera, Hubn. Hubn. Pap. Tab. 39. f. 1 76. (fcem ). 

31. — Moera, Linn. . Ernst, 1. PL XXVI. f. 51. a. b. 

32. — Adrasta, Hoff-\ Ernst, I. PL LXXXII.Suppl.II. 

mansegg J PL 3. fig. 50. a. b. c. bis. 

33. — Megcera, Linn. Ernst, I. PL XXVI. f. 50. a.b. c. 

d. (e. f. var.) 

34. -— Egeria, Linn. Ernst, I. PL XXV. f. 49. a— d. 

35. — Meone, Hubn. Cram. Pap. Exot. PL CCCXIV. 

f.E. F. 

D. 36. — Galatea, Linn. Ernst, I. PL XXX. f. 60. a— d. 

37. — Lachesis, Hubn. Hubn. Pap. Tab. 41. f. 186. 187. 

(mas.) Tab. 42. f. 188. 189. 
(fcem.) 

38. — Clotho, Fab.... Ernst, I. Pl.V. Suppl. III. f. 61. 

a. b. bis. 

39. — hies, Hoffm. . . — — jf — 

40. — Arge, Sulzer. . Ernst, I. PL XXX. f. 61. a. b. 

41. — Syllius, Herbst. Ernst, I. PL XXX. I e. f. 

* Sp. n.— H. alis subdentatis fuscis: anticis utrinque ocello, punctisque 
subtus duobus albis : postick snpra immaculatis, subtus albo fuscoque mar- 
moratis, fascia crenata concolore albo marginata venisque albis. 



286 Ochsenheimer's Genera of the Lepidoptera of Europe. 

Icon. 
Hiibn. Pap. Tab. 44. f. 202. 
Hiibn. Pap. Tab. 97. f. 491. 492. 

(mas.) 493. 494. (foem.) 
Ernst, I. Pl.LXXXI. Suppl.II. 

PL 2. f. 41. a. b. bis. 
Ernst, I. PL XXIV. f. 45. a. b. 
Hiibn. Pap. Tab. 50. f. 231.232. 

(foem.) 
Hiibn. Pap. Tab. 106. f. 540.541. 

(mas.) 542. 543. (foem.) 
Ernst, I. PL XXIII. f. 41. a— d. 
Hiibn. Pap. Tab. 104. f. 530. 531. 

(mas.) 532. 533. (foem.) 
Hiibn. Pap. Tab. 98. f. 497. 

(mas.) 498. 499. (foem.) 
Hiibn. Pap. Tab. 98. f. 500. 501. 

(mas.) 
Hiibn. Pap. Tab.l 12. f. 578. 579. 

(mas.) 
Ernst, I. PL XXIV. f. 44. a. b. 
Hiibn. Pap. Tab. 48. f. 223. 224. 

(mas.) 
Hiibn. Pap. Tab. 45. f. 105. 106. 

(mas.) 
Hiibn. Pap. Tab. 104. f. 528. 

529. (mas.) Tab. 101. f. 515. 

516. (foem.) 
Ernst, I. Pl.XXIV.f.43.a.b.e. 

Ernst, I. PL XXIII. f. 42. a. b. 
Esp. Schm. I. Th. Tab. 118. 

Cont.73.f.2.(mas.)f. 3.(foem.) 
Hiibn. Pap. Tab. 109. f. 561. 

562.(mas.)Tab.49.f.228.229. 

(foem.) 
Ernst, I. PL LXIV. Suppl. X. 

f. 42. a — e. bis. 
Hiibn. Pap. Tab. 50. f. 233. 234. 

(foem.) 
Hiibn. Pap. Tab. 99. f. 502. 503. 

(mas.) 504. 505. (foem.) 
Ernst, I. PL LXV. Suppl. XI. 

f. 42. a. b. tert. 
Ernst, I. PL LXV. Suppl. XI. 

f. 42. a. b. quart. 



E. 42. 
43. 


H 


Species. 
. Epiphron, Fab. 
Pharte, Hiibn. 


44. 




Melampus, Esp. 


45. 
46. 




Cassiope, Fab. 
Arete, Fab. ... 


47. 


— 


Mtiestra, Hiibn 


48. 
49. 




Pyrrha, Fab. . 
Oeme, Hiibn. . 


50. 


— 


Psodea, Hiibn. 


51. 


— 


Afer, Fab 


52. 


— 


Ceto, Hiibn.... 


53. 




Medusa, Fab. 


F. 54. 


— 


Stygne, Hiibn. 


55. 


— 


Melas, Herbst. 


56. 


— 


Alecto, Hiibn. 


51. 




Medea, Fab. . 


58. 
59. 


-— 


Ligea, Linn. . 
Euryale, Esp. 


60. 


— 


Embla, Fab. . . 


61. 


— 


Pronoe, Fab. . 


62. 


— 


Goante, Esp. . 


63. 


— 


Gorge, Hiibn. 


64. 


— 


Manto, Fab.... 


65. 


— 


Tyndarus, Fab. 



Mr. R. Phillips on the Sulphates of Nickel 287 

Species. Icon. 

G. 66. H. Dams, Linn. . Ernst, I. PI. XXIX. f. 58. a. b. 

67. — Pa?nphilus 9 L\nn. Ernst, I. PI. XXIX. f. 56. a. b. 

68. — Lyllus, Esp.... Hiibn. Pap. Tab. 109. f.557. 558. 

(fern.) 

69 . — . Ipkl^ Fab. ... Hiibn. Pap. Tab. 53. f. 249. 

(mas.) 250. 251. (fcem.) 

70. — Hero, Linn.... Ernst, I. PI. XXIX. f. 59. a. b. 

71. — (Edipus,Fab.. Hiibn. Pap. Tab. 52. f. 245. 246. 

(mas.) 

72. — Arcania, Linn. Ernst, I. PL XXIX. f. 57. a — d. 

73. — Dorus, Esp.... Ernst, I. PL LXVIII. Suppl. 

XIV. f. 57. a. b. bis. 

74. — Satyrion, Esp. Hiibn. Pap. Tab. 53. f. 254. 255. 

(mas.) 

75. — Corinna, Hiibn. Hiibn. Pap. Tab. 105. f. 534. 537. 

(fcem.) 

76. — Leander, Fab. Hiibn. Pap. Tab.l03.f.526. 527. 

(fcem.) 

77. — Phryne, Fab. . Ernst, I. PL VIII. Suppl. III. 

f. 58. a. b. bis. 
[To be continued.] 



L. On the Crystalline Forms and Composition of the Sulphates 
of Nickel. By R. Phillips, F.R.S. $c. 

r T v HE Annates de Chimie et de Physique for May last, con- 
* tains a memoir by Mons. E. Mitscherlich, " On the cry- 
stalline forms and composition of some sulphates" : his state- 
ments, with respect to sulphate of nickel, appear to require 
some notice. 

In the present paper the author has given only one of the forms 
of sulphate of nickel, stating that in a memoir which will shortly 
appear he shall describe another. The primary form of the 
crystal now under examination, Mons. M. considers as an acute 
octahedron with a square base ; but it may be regarded, as 
shown by Mr. Brooke in the Annals of Philosophy, vol. 6. N.S., 
p. 4 37, as a square prism, parallel to the planes of which it may 
be cleaved. The composition of sulphate of nickel M. Mitscher- 
lich states to be: 

Sulphuric acid 28*51 

Oxide of nickel 26*71 

Water 44*78 

100-00 
M. Mitscherlich then makes the following statement : "In an- 
other 



288 Mr. R. Phillips on the Crystalline Forms 

other memoir which will soon appear, I shall describe another 
crystalline form of sulphate of nickel and of sulphate of zinc, 
which is entirely differentfrom that which I have now described; 
the production of these different forms depends upon the tem- 
perature at which the crystals are formed. The seleniate of zinc, 
which at a temperature of 50° Fahr. gives prismatic crystals, 
changes its form when the prismatic crystals are exposed on 
paper to the heat of the sun. This phenomenon may be also 
extremely well observed in sulphate of nickel. A temperature 
of 59° of Fahr., still produces prismatic crystals. If these 
crystals, of a certain size, be exposed to the sun in a close 
vessel, it frequently happens that they retain their external 
form, so that the angles at which the planes meet may be mea- 
sured ; but if they be broken, they are found to consist of 
crystals frequently several lines in length, which are octahe- 
drons with a square base, the angles of which I have been 
able to measure. This change requires two or three days. 

"I have determined by a very complete analysis the quantity 
of water contained in this compound. The octahedrons with 
a square base, into which the prismatic crystals were con- 
verted, by several days' exposure to the sun in an uncovered 
[covered?] vessel, gave me 30*14 per cent, of sulphuric acid; 
some other octahedrons with a square base derived from the 
crystallization of a hot solution yielded 29*88. If we take the 
mean of these two results, we must admit that the octahedron 
of sulphate of nickel with a square base contains: 

Sulphuric acid 30*02 

Oxide of nickel 28*13 

Water . 41*85 



100*00 
" It follows from this phenomenon," concludes M. Mitscher- 
lich, "as well as from several others which I have before an- 
nounced, that the isolated particles of matter in solid bodies 
are moveable with respect to each other, and that they may 
assume different relative positions to those which they origi- 
nally had, without its being necessary to render the bodies 
fluid. 

Now without asserting it to be the case, I do most certainly 
think that Mons. M. has attributed the difference in the form of 
these crystals to a wrong cause ; and at any rate I am quite 
sure that the crystals of sulphate of nickel of both kinds may 
be procured at pleasure, and totally independently of the tem- 
perature at which the crystallization occurs. 

I have already stated that M. Mitscherlich considers as an 
octahedron that which Mr. Brooke regards as a square prism ; 

either 



and Composition of the Sulphates of Nickel. 269 

either of which forms, from the relation which they bear to 
each other, may be assumed as the fundamental crystal : 
while he has not given at all the precise form of the prismatic 
variety, arid which Mr. Brooke in a paper already quoted, has 
described as a rhombic prism so nearly approaching that of 
sulphate of zinc, that he is inclined to doubt whether there is 
any real difference between them. 

In this memoir the difference between the crystalline forms 
is clearly traced by Mr. Brooke ; and I have endeavoured to 
prove that the difference is dependent not upon the propor- 
tion of water, as Mons. M. appears to suppose, but owing to 
one of the crystals containing more sulphuric acid than the 
other, although not in atomic proportion. 

The analyses which I have given in the Annals of Philosophy, 
N.S. vol. vi. p. 439, show that the quantity of acid in 100 of 
the square, is to that in the rhombic prisms as 30 to 28*16, — 
a difference of nearly 2 per cent. ; and the quantities of water 
are respectively 45'54 and 43*8, a difference of almost If per 
cent, instead of nearly 3, as stated by M. Mitscherlich. 

That excess of acid without any variation of temperature is 
capable of producing variation of form, is proved by the fol- 
lowing experiment : I dissolved 200 grs. of rhombic prisms in 
water, and added to the solution about half its weight of sul- 
phuric acid, and put the solution to crystallize in a room, the 
temperature of which varied from about 60° to 64°. The cry- 
stals first obtained were similar to those dissolved, viz. rhom- 
bic prisms ; afterwards I procured a mixture of rhombic and 
square prisms ; and lastly, square prisms only, and this with- 
out any greater variation in the temperature than that which 
I have already noticed. 

From this experiment it is evident, that owing to the for- 
mation of rhombic crystals in the first instance without excess 
of acid, the relative proportion of sulphuric acid to the oxide 
of nickel was subsequently so much increased, that square 
prisms were formed, which from the analysis already stated 
contain a larger proportion. of acid. 

In corroboration of the inference that the difference of form 
is dependent upon that of the quantity of acid, I shall merely 
add that a solution of 200 grs. of rhombic prisms, to which 
no sulphuric acid was added, and crystallized in the same 
room already mentioned, yielded merely rhombic without any 
admixture of the square prisms. 

To the foregoing statements I may add, that rhombic cry- 
stals of sulphate of nickel, when exposed to the air, effloresce, 
which is not the case with the octahedral variety; and it ap- 
pears to me probable, that when rhombic prisms which have 
'New Series. Vol.4. No. 22. Oct. 1828. 2P been 



290 Mr. George's Chemical Examination of some of the 

been deposited from a solution containing excess of acid, are 
exposed to the sun, the supposed formation of octahedral cry- 
stals is merely a removal of the enveloping rhombic crystals 
by efflorescence, and the consequent development of the in- 
closed octahedral crystals ; for rhombic crystals formed in the 
requisite mode frequently contain minute octahedrons, which 
may be observed by merely breaking the crystal, which will 
explain their occurrence, even without any external change in 
the enveloping rhombic prism. 



LI. Chemical Examination of some of the Substances connected 
with an Egyptian Mummy, By E. S. George, F.L.S. Ser 
aetary to the Leeds Philosophical and Literary Society*. 

I. — A PORTION of the pounded wood found about the 
-**- throat and breast, was digested in boiling alcohol ; a 
deep brown solution was thus obtained, which, after being 
filtered, remained permanently transparent. The odour of 
myrrh was very sensible, and the alcoholic extract afforded 
with water the characteristic precipitate of solutions of myrrh. 
By a careful examination of the wood, it was separated into two 
parts ; the one, and that the most abundant, was myrrh, and 
the other cassia. The odoriferous wood from the abdominal 
cavity, subjected to the same treatment, gave similar results. 

II. — The folds of cloth with which the mummy was ban- 
daged, presented, near the body, a much deeper colour than 
the external wrappings. A portion having a deep chesnut 
colour was digested in boiling water ten minutes ; a very deep 
brown-coloured solution was thus obtained. The addition of 
a few drops of gelatine to this solution, gave an immediate 
precipitate, indicative of the presence of tannin : this result 
was rendered more" striking by concentrating the solution, 
when large flakes of the tannate of gelatine were precipitated. 
A few drops of a solution of muriate ofbarytes were added to 
this aqueous extract : an immediate precipitate fell down ; it 
was found to consist principally, of carbonate of barytes, and 
by the requisite tests, the presence of the carbonate, muriate, 
and sulphate of soda was discovered, the former salt in the 
largest proportion. 

III. — Analysis of the fleshy parts of the body. 

1. — A piece of thick abdominal muscle, weighing 97 grains, 

* From Mr. Osburn's " Account of an Egyptian Mummy presented to 
the Museum of the Leeds Philosophical and Literary Society, by the late 
John Blayds, Esq."— A further notice of this work will appear in our next 
Number. 

was 



Substances connected with an Egyptian Mummy. 291 

was macerated one hour in water, at about 1 70 u ; the solution 
had a light yellow colour and a saline taste. 

2. — The portion remaining was repeatedly digested in boil- 
ing alcohol (*835 rectified spirit of wine), until the spirit ceased 
to acquire any colour : the alcoholic solutions deposited a yel- 
low-coloured substance upon cooling. The whole of the so- 
lutions were mixed together and diluted by about twice their 
amount of water; an immediate yellow-coloured precipitate 
fell down : on the application of heat the precipitate melted, 
and floated upon the surface of the water ; it was ascertained 
that this substance became solid at 110° Fahrenheit: it was 
thus removed, and after being dried between the folds of fil- 
tering paper, weighed 23 grains. 

3. — The remaining liquid, when cool, was opaque, but upon 
being heated to 212° became transparent. On evaporation 
to dryness, it weighed 12 grains, and proved to be almost en- 
tirely gelatine. 

4. — The aqueous solution, (No. 1.) was evaporated to dry- 
ness ; the residue, which was of a dark-brown colour, brittle, 
and covered with bright saline crystals, weighed 9 grains. 
The addition of a few drops of water converted the whole of 
it into a mucilage ; the saline part consisted almost entirely of 
carb&nate of soda, with some muriate and sulphate, and ap- 
peared identical with the salt found in the bandages. The 
mucilaginous portion was gelatine. 

5.— The part undissolved by the action of both water and 
alcohol, weighed,when dry, 51 grains ; it did not inflame readily, 
and gave out when burning the peculiar smell of burnt horn. 

6. — The substance (2) had a deep yellow colour, and a greasy 
feel very much like that of cerate ; it possessed little either of 
taste or smell when cold : when fused, it gave out the odour 
of the spices found about the body ; it inflamed, and emitted a 
large quantity of light during its combustion. It was entirely dis- 
solved in liquid ammonia, and the solution remained perfectly 
transparent on the addition of water ; this alkaline solution ex- 
posed in an evaporating-dish to the air, deposited a soapy 
substance as the ammonia evaporated. Potash formed with 
this substance a soap soluble in water. Boiling nitric acid 
scarcely acted upon it. Subjected to destructive distillation, 
it presented the following appearances. Upon the application 
of heat it melted, and bubbles of air were rapidly disengaged ; 
— after a short time, the liquid became quiescent, the retort 
was filled with dense white fumes, and a few drops of water 
were condensed. No trace of the formation of ammonia was 
perceptible, nor did the water taste acid ; at a more elevated 
temperature a dark-coloured oily fluid trickled down the beak 

2 P2 of 



292 Mr. George's Chemical 'Examination of some of the 

of the retort, and was condensed into a fatty substance, which 
increased and became more solid as the distillation advanced; 
at the same time a pungent and disagreeable vapour passed 
over, having very much the odour of candle-snuff". At the close 
of the experiment, a bright charcoal remained in the retort. 

7. — A portion of muscle was digested in boiling spirit of 
turpentine: the solution, which was deep coloured, being eva- 
porated to dryness, left a substance similar to that separated 
by alcohol. 

8. — In order to determine whether the substance separated 
by alcohol and essential oil of turpentine was formed by their 
action upon the animal matter, a portion of muscle was di- 
gested one hour in boiling water ; the surface of the water was 
covered by an oily substance, which, on cooling, became solid, 
and resembled in all its properties that separated 1 . 2. and 7. 
The aqueous solution contained a considerable quantity of ge- 
latine. 

9. — A piece of thick muscle covered with skin was digested 
four days in cold alcohol (sp. gr. 835), the solution acquired a 
dark-brown colour ; by spontaneous evaporation, a white sub- 
stance in plates was deposited. The solution, when reduced 
to one-fourth of its original bulk, was filtered, and the solid 
part dried upon the filter : it had precisely the same properties 
as the substance obtained by the action of boiling alcohol, ex- 
cept being of a much lighter colour. Upon evaporating the 
solution which passed through the filter to dryness, a very small 
quantity of a body heavier than water, insoluble in that liquid, 
and which possessed all the characters of resin, remained. 

IV. — A small fragment of the visceral substance, supposed 
to be the liver, was examined. It was covered with a thin 
coating of saline efflorescence, mixed with earth. The salts 
proved to be the same as those before examined, — the carbo- 
nate, muriate, and sulphate of soda; tests were carefully ap- 
plied to detect, if present, the nitrate of potash, but without 
discovering any trace of that salt. The earthy substance ef- 
fervesced wich acids. 

The liver was next repeatedly digested in alcohol and water. 
Gelatine was the only substance separated by these solvents — 
the aqueous solution contained a large quantity. I found in 
the course of this set of experiments, that although gelatine is 
insoluble in pure alcohol, yet the rectified spirit of wine (sp. 
gr. 835) dissolves it. 

V. — The drops of a resinous substance from the cavity of 
the head, were found to be pure resin, having a very fine 
odour, which was not acertained to resemble that of any known 
resin. 

In 



Substances connected with an Egyptian Mummy. 293 

In many of the substances discovered by this analysis, the 
characters are so unequivocal as to render their identification- 
easy and certain ; — such are the salts, the tannin, and colour- 
ing matter of the bandages ; the gelatine obtained from both 
the muscular part and the viscera ; the resins, and the pounded 
spices from the body. There is, however, some difficulty in 
arriving at a conclusion with the remaining, and indeed most 
important substance ; for although its appearance, and many 
of its chemical properties closely resemble those of wax, some 
others approach very nearly to the properties of animal sub- 
stances, as adipocire. 

Like wax, this substance is soluble in alcohol, but differs in 
degree ; cold alcohol, which scarcely acts upon wax, dissolving 
it readily. With wax, the alkalies form soaps almost insoluble 
in water : with this substance, the alkaline soaps are very solu- 
ble. — Nitric acid scarcely acts upon wax ; boiling nitric acid 
exerts a very slight action upon this substance, for the loss of 
colour depends upon the removal of a small quantity of resin, 
which it was shown (9.) that the alcoholic solution from the 
muscular part contains*. 

The results of the destructive distillation of both very closely 
agree. Comparative experiments with equal weights of wax 
were made ; the only difference noticed was, that in the distil- 
lation of the wax the product was more acid and empyreu- 
matic, and that the quantity of permanent gases liberated was 
larger. With adipocire this substance agrees in its solubility 
in cold alcohol, in forming alkaline soaps soluble in water, in 
its point of fusibility, which is lower than that of wax, and in 
the action of acids. 

Whether this substance be an adipocirous body formed by 
the process of embalming, or wax introduced during that pro- 
cess into every part of the deepest muscle, I shall not deter- 
mine. In the appearance of the mummy there is much to fa- 
vour the former opinion ; the bones of the most exposed parts, 
as the head, are not in the slightest degree penetrated by this 
waxy substance, in a fused solution of which, we must suppose 
the body to have been many days immersed ; nor is the wax 
found in greater abundance upon and near the surface, than 
in the most deeply seated parts ; the cuticle covers every part 
of the body, which scarcely would have been the case if ex- 
posed so long to an elevated temperature. 

I am aware that Dr. Granville has, from a very elaborate 
and interesting examination of a mummy, concluded that wax 

* The oil of cedar is one of the ingredients in the process of embalming. 
The resinous appearance may, probably, have arisen from the use of this 
condiment. — Note by Mr. Osburn. 

was 



294? Geological Society. 

was employed in the process. This mummy, in some respects, 
differs from his, in the perfect state of the viscera, and in the 
total absence of bitumen, or of any but the most expensive 
woods and resins. 



LII. Proceedings of Learned Societies. 

GEOLOGICAL SOCIETY. 

June 20.— TOHN, Earl of Shrewsbury, of Great Stanhope Street, 
M May Fair, and of Alton Abbey, Staffordshire ; Robert 
Allan, Esq. of Charlotte Square, Edinburgh ; W. S. Henwood, Esq. of 
Perran Wharf, Truro, Cornwall 3 and the Rev. John Ward, Vicar of 
Great Bedwin, Wilts, — were elected Fellows of this Society. 

A paper was read <c On the Geology of Bundelcund, Boghelcund, 
and the districts of Saugor and Jabalpoor in central India." By 
Captain James Franklin, of the Bengal Army, F.R.S. F.A.S. 

The tract of country described by the author is a portion of the 
lowest northern steps of the Vindaya mountains, situated between the 
latitudes 22° 40", and 25° 20" N., and the longitudes 78 a 30", 
and 83° E. j having on its north-eastern extremity the towns of Mir- 
zapoor and Allahabad, and near its southern limit, those of Tendu- 
kaira, Singpoor and Mundla. 

In this extent of country the principal situations examined by Cap- 
tain Franklin were, the pass of Tara in the first range of hills ; the 
pass of Kattra in the second range j the cataracts of Billohi, Bauti, 
Kenti, Chachye, and of the Tonse river j the neighbourhood of the 
villages of Simmereah, Hathee, Birsingpur, Sohawel, Nagound, and 
Lohargaon ; the bed of the Cane river near Tigra; the neighbour- 
hood of Hatta, Narsing-hagarh, Patteriya, Saugor, Tendukaira ; the 
valley of the Nermada river j Garha-kota, Great Deori ; the Bandair 
and Kymur hills j Jabalpoor, and the waterfall of Beragurh. 

The succession of formations observed by the author consisted, 
in a descending order : — 1. Of diluvial deposits. — 2. Of overlying 
rocks of the trap formation. — 3. Of a compact limestone. — 4. Of 
red-sandstone. — And, lastly, 5. Of primitive rocks, including granite, 
gneiss, &c. The paper is illustrated by a geological map and sec- 
tion of the country 5 and the author particularly wishes to direct the 
attention of geologists to the limestone of the second range of hills, 
which he is of opinion corresponds with the lias-limestone of En- 
gland, a formation which has not hitherto been shown to exist in 
India. 

Having commenced his route at Mirzapoor on the Ganges,— in a 
district covered with alluvium reposing in some places on beds of 
" Canker," in others on sandstone, the author ascended the first 
range of hills at the pass of Tara. These hills are composed of fine- 
grained sandstone horizontally stratified, and more or less coloured 
by red oxide of iron j the rock appears to be saliferous, and is in 
many places quarried for architectural purposes ; and it seems to cor- 
respond 



Geological Society. 295 

respond with the central portion of the new-red-sandstone of En- 
gland. 

At the pass of Kattra, near the summit of the second range of hills, 
a friable variegated sandstone appears, in which thin laminae of sand- 
stone alternate with red clay, resembling the red marie of England, 
both reposing on slaty marie coloured by chlorite, which rests, appa- 
rently, on massive horizontal strata, resembling clay-slate or grau- 
wacke. 

At the bottom of the cataract of Billohi, 398 feet in height, argilla- 
ceous sandstone was found, tinged deeply by red oxide of iron, and 
containing disseminated mica, — on which reposed a siliceous sand- 
stone of a more compact texture. 

Greenish white arenaceous sandstone not quite so compact was 
found at the cataract of Bauti, 420 feet below the summit, varying 
in colour as it ascended : and twenty-four miles further westward, at 
the cataract of Kenti, and at a depth of 272 feet, as well as at the ca- 
taracts of Chachye and of the Tonse river, sandstone of the same 
general character was observed rising to the surface. 

The sandstone of Simmereah is sometimes ferruginous, at others 
slaty, and interspersed with mica ; in the neighbourhood of Hathee it 
is succeeded by what the author considers as the equivalent of the 
lias-limestone. 

At Birsingpur, in the bed of a small river, is a stratum of red marie 
or sandstone, containing laminae of calc-spar j at Sohawel the red 
marie underlies the limestone above mentioned ; and at Nagound in 
the bed of the Omeron river, the lower and central beds of limestone 
are exposed to view, containing fragments of fossil wood, stems of 
ferns, — and, as the author states, the gryphite which is characteristic 
of this formation in Europe. 

This limestone appears also at Hatta and Narsinghagarh reposing 
on red marie, and in the latter situation is tinged green by chlorite. 
At Patteriya, where the limestone comes into contact with trap, the 
strata assume in some places the form of chert. 

The aspect of this limestone is dull and earthy ; its stratification ho- 
rizontal or nearly so, and always conformable to the red marie on 
which it reposes. 

Between the pass of Patteriya and Saugor, the author met with no 
other rock than trap, generally in the form of boulders imbedded in 
friable wacken, and composed of concentric layers : beneath the bould- 
ers is a bed of indurated wacken and basalt -, and under the latter a 
stratum of impure limestone, in some parts containing a large pro- 
portion of alumine j below the limestone is a stratum of amygdaloid, 
containing calc-spar and a few zeolites, which at Saugor reposes 
on sandstone. 

The trap of Saugor continues without interruption to Tendukaira : 
it contains abundance of chalcedony, semiopal, mealy zeolite, ca- 
chalong, agates, jaspars and heliotrope. 

At about the distance of three miles from the foot of the hills near 
Tendukaira, in the valley of the Nermada river, the older rocks are 
exposed to view, in strata which are highly inclined, — in some in- 
stances 



296 Geological Society, 

stances nearly vertical, and in all cases unconformable to those already 
noticed. 

On his route from Tendukaira to Garha-Kota, captain Franklin 
was enabled to ascertain the eastern boundary of the trap formation, 
which is throughout intimately associated with earthy limestone - f 
the whole series reposing on red marie and sandstone. 

Trap in horizontal strata was also observed for an extent of three 
miles near Great Deori, previous to the appearance of the sandstone 
of the Bandair hills, which last-mentioned rock the author is of opinion 
corresponds with the new-red-sandstone of England ; the same chain 
of hills is composed of sandstone opposite Nagound, Lohargaon,Tigra, 
and Gurreha. The Kymur range in some parts appears to be composed 
of quartz-rock, varying to siliceous grit, in strata nearly vertical j 
but to the S.W. near Hirapur, the rock becomes more compact ; 
and still further west, opposite Googni, it is intermixed with clay- 
slate and schistose limestone. 

A broad valley covered with diluvium, intervenes between the Ky- 
mur range of hills and Jabalpoor; and near that town another range is 
situated, composed of granite containing flesh-coloured felspar, smoky 
quartz, black mica and hornblende ; — and in which, also almost 
every rock commonly associated with granite is to be found. 

Snow-white dolomite, traversed occasionally by chlorite schist, is 
to be seen near the waterfall of Beragurh, intimately associated with 
quartz j it is here capable of taking a fine polish, and scarcely effer- 
vesces with acids $ but a few miles further west, near Bograi, it is ex- 
ceedingly friable, and effervesces freely : it moreover contains crystals 
of Tremolite. 

Captain Franklin observes that a part of the southern barrier of the 
valley of the Nermada river, like the northern barrier opposite Ten- 
dukaira, is composed of trap-rocks, the contour of which, to the 
extent of 80 miles, he has laid down on his map. The eastern 
deposit of overlying rocks extends southwards as far as Chuparah, 
and thence eastward towards Mandela, Omercuntuc, and Sohagpoor j 
but whether it is united with the great central mass, he was unable 
to ascertain. 

The paper concludes with some inferences from the observations ; 
and after stating the opinion of the late Dr. Voysey, that "the basis 
of the whole peninsula of India is granite," (Asiatic Researches, Vol. 
XV. page 123.) the author observes, — 1. That although granite is 
very near the surface in many parts of the tract which fell under his 
examination, yet there is here, as in other countries, a series of pri- 
mary stratified rocks intervening between the granite and secondary 
formations j which series however, there is reason to conclude, is 
thin and often wanting. 

2. The sandstone formation has a visible thickness of 420 feet at the 
cataract of Bouti, and is considerably thicker no doubt near Chachye 
and the Bandair hills, &c. The limestone formation on the contrary, 
which in other countries sometimes forms mountain tracts, and occu- 
pies extensive portions of the earth's surface, is in India a mere 
plastering, as it were, over the red marie or sandstone 5 and Captain 

Franklin 



Geological Society. 297 

Franklin doubts whether it ever attains a thickness of 1 00 feet j 50 
feet being perhaps a fair average. He never met with it in any other 
situation than on the summit of the second range of hills. 

3. The overlying trap-rocks are not only the most extensive, but, 
considering them in a geological view, the most important formation 
in this part of India. The thickness of this formation is variable : 
it reposes on every rock indiscriminately, from granite upwards j and 
at Saugor it maybe seen on sandstone, where its inferior boundary is 
about 1350 feet above the sea. In the centre of India it occupies the 
summits of the highest mountains j and at Bombay it descends to the 
level of the sea. 

There are two kinds of basaltic rock in the district of Jabalpoor, 
clearly of distinct formations - } the older variety penetrates the grau- 
wacke stratum, in the bed of Nermada river, near Lamaita ; the 
younger is an overlying rock like that at Saugor, — but reposing on 
granite, and containing a greater proportion of augite and olivine. 

Captain Franklin also describes a calcareous conglomerate, found 
in the beds of most of the rivers whose sources or channels are in the 
trap, and of sufficient cohesion for architectural purposes : its strati- 
fication is always horizontal, and in point of age he thinks it must be 
classed with the tufas and concretionary formations so prevalent in 
India. 

An appendix to this paper contains the results of barometrical and 
thermometrical observations made between Nov. 1826, and Feb. 
1827, on the route from Mirzapoor to Saugor, and thence to Ten- 
dukaira and Jabalpoor $ with the heights of fifty-four places above 
the sea, and the latitudes and longitudes of the respective stations. 

An extract was read of a letter from Samuel Hobson, Esq. to Dr. 
Roget, F.G.S. Sec. R.S. &c. (dated at New Orleans, 6th April, 1827,) 
and enclosing an account of some gigantic bones, — by Samuel W. 
Logan, M.D. 

The place where these bones had been found is not mentioned ; 
but at the date of the letter, they were exhibited publicly at New 
Orleans. Dr. Logan describes them as consisting of one of the bones 
of the cranium, fifteen or twenty vertebrae, two entire ribs and a part 
of a third, one thigh-bone, two bones of the leg,, and several large 
masses of a cancellated structure. 

The cranial bone was twenty feet and some inches in its greatest 
length, about four feet in extreme width (for the bone tapers to a 
point), and it weighed twelve hundred pounds. Dr. Logan inclines 
to think that this is the temporal bone. 

The vertebrae, consisting of a body, oblique transverse, and spinous 
processes, gave sixteen inches as the mean diameter, and twelve 
inches as the depth of the bodies j while the passage for the spinal 
cord measured nine inches by six. The spinous processes stand 
off backwards and downwards, fourteen inches in the dorsal, and 
somewhat less in the lumbar vertebras, three of which latter are 
entire. 

The ribs, well formed and in a perfect state of preservation, mea- 
sured nine feet along the curve, and about three inches in thickness. 

New Series. Vol.4. No. 22. Nov. 1828. 2 Q The 



298 Astronomical Society. 

The thigh-bone, measured in length, gave only one foot six inches, 
but is very thick. The bones of the leg are of similar dimensions, 
but perhaps a little more slender. 

It had been conjectured that the animal to which these remains be- 
longed, was amphibious, and perhaps of the crocodile family - } and 
the conjecture appeared to Dr. Logan to be justified by the great 
length and flatness of the head (judging from the single specimen of 
the cranial bone), and the shortness of the limbs. It was also sup- 
posed that the animal, when alive, must have measured five and twenty 
feet around the body, and about one hundred and thirty feet in 
length. 

An Extract was read of a letter from his Grace the Duke of Buck- 
ingham, to Professor Buckland,V.P.G.S. dated at Naples, 3rd April, 
1828, giving an account of certain phenomena, which attended the 
late eruption of Vesuvius. The author states that the Solfaterra was 
in no degree affected by the eruption. 

A Letter was read from Charles Stokes, Esq.F.G.S. F.R.S. to W. J. 
Broderip, Esq. Sec. G.S. explanatory of three drawings of Echini, re- 
presenting, — I. A specimen of Galeorites albo-galerus (Lam.), from 
the chalk, in which the plates of the mouth, consisting of five pairs, are 
preserved in situ ; — 2. A Cidaris, also from the chalk, in which por- 
tions of the plates of the mouth and the teeth are visible : they are 
displaced, but exhibit a system quite analogous to that of the recent 
cidaris ; — and, 3. A Cidaris from Stonesfield, in which the anal plates 
are in the best preservation. 

At the close of this Meeting, which terminated the Session, the 
Society adjourned till Friday Evening, the 7th of November ; when 
they will meet at their Apartments in Somerset House. 

ASTRONOMICAL SOCIETY. 

The reading of Mr. South's paper " On the Occultation of 8 Pis- 
cium by the Moon, &c." commenced in April, was resumed and con- 
cluded. 

Of all the phenomena which occupy the attention of the practical 
Astronomer, the Author of this paper considers, that no one admits 
of such accurate observation, as does the occultation of a fixed star 
by the moon : occasionally, however, a circumstance presents itself 
to his notice, which merits peculiar consideration, namely an apparent 
projection of the star, upon the lunar disk ; the instances in which 
this anomaly has been observed in this country, are indeed rare ; and 
has, he says, led many to consider it the attendant of a lively ima- 
gination. If, however, we dispassionately review the observations 
of Continental Astronomers, of unsullied reputation, there will, 
Mr. South says, be little reason to doubt the fact of apparent projec- 
tion, although perhaps there may be considerable difficulty in ar- 
riving at its cause. % 

The only instance in which Mr. South has witnessed the pheno- 
menon, was previous to the occultation of 8 Piscium, on the 6th of 
February 1 82 1 . (Latitude of the Observatory 5 1 ° 30' 2", 97 North. 
Longitude of the Observatory 2l 8 ,76 West.) .The night was beau- 
tifully 



Astronomical Society. 299 

tifullv fine, the moon's dark limb and unilluminated disk unusually 
distinct: the atmosphere peculiarly serene, and the moon's limb, as 
well as the star, remarkably steady. The observation was made 
with his five-feet equatorial, furnished with a power of 127 ; the ob- 
server was at the telescope 4 or 5 minutes before the immersion 
could happen : every thing went on as usual, till the moon's limb 
came in contact with the star ; but the expected occultation did not 
occur. He noted the time when the apparent contact took place, 
which was at 3 1 ' 20'" 54 s ,0 by the clock. The star, unshorn of any 
of its splendour, remained visible on the unillumined lunar disk, till 
311 2]m 2%9 by the clock, when it instantaneously disappeared. Not 
the slightest sensible deviation in the star's place occurred between 
the moments of apparent contact and subsequent disappearance j 
and it exhibited the same perfectly defined disk whilst on the moon's 
limb, as it was observed to have, previously to the contact. 

The corrections for the clock's error being applied, the observa- 
tions will stand thus : h m s 

Apparent contact at 3 20 29,87 

Instantaneous immersion . . 3 20 38,77 
Emersion 4 14 32,88 

The only corresponding observations of this occultation which have 
come to Mr. South's knowledge, were made by Mr. Littrow and 
Mr. Baily, and their results are given in the Memoirs of this Society. 
As Mr. Littrow has not narrated any peculiarity, it is probable none 
presented itself to him j and Mr. Baily has authorized Mr. South to 
state that he saw nothing anomalous ; a circumstance certainly im- 
portant, seeing that in Blackman Street the apparent projection of 
the star on the moon's disk, continued nearly nine seconds of time. 
On the same evening in Blackman Street, a star of the 8th or 9th 
magnitude suffered occultation by the moon's dark limb, nearly at the 
same part, at which 8 Piscium entered on the disk ; the star disap- 
peared instantaneously at 5 h 2 m fi s ,0 by Mr. South's clock 5 prior to 
occultation, however, this star was not seen projected upon the limb ; 
but the low altitude of the moon rendered the observation less sa- 
tisfactory than was the previous occultation of $ Piscium. 

The recorded observations of other Astronomers are then quoted 
in the words of their respective authors, or in authentic abstracts ; 
and are principally derived from the Memoires de I' Academic Royale 
des Sciences, the Histoireet Memoires de i Academie Roy ale des Sciences 
de Toulouse, the Histoire Ce'leste Francaise, the Connoissance des Terns, 
and the Observations Astronomiques foites (I VObservatoire Royal de 
Paris, torn. I. : this done, they are arranged in a tabular form, pre- 
senting at one view, the name of the observer, the place of observa- 
tion, the nature of the. occultation, the age of the Moon, and her 
motion at the time, whether northerly or southerly j information of a 
nature not easily to be abridged, and far too voluminous, to have in- 
sertion in the Monthly notices of the Society's proceedings. 

On perusing them, however, we find, that more than 20 stars have 
exhibited peculiarities at, or on) the moon's limb, prior to immersion 
behind it, or emersion from it j thai the anomalies are not confined 

to 



300 Astronomical Society. 

to stars of a certain magnitude or colour ; nor are they dependent 
upon any particular age of the moon. Most of them have furnished 
but solitary instances of peculiarity y viz. Spica Virginis, y Librce, 
132 Tauri, a 1 Cancri, X Aquarii, 249 Aquarii, 187 Sagittarii, y Tauri, 
p Leonis, p Geminorum, 8 Cancri, and 8 Piscium. One, Regulus, af- 
fords three, whilst to Aldebaran we are indebted for no less than 
twenty instances of anomaly. 

On reference to the list, the anomaly alluded to, it will be seen, 
stands not upon the testimony of a single individual, but is supported 
frequently by the evidence of a second, and sometimes even of a third 
person j occasionally they are co-observers at the same station ; at 
other times they are at different parts of the same city ; whilst in some 
instances, they are separated by a very considerable distance. On 
the other hand, the conflicting testimonies, where we should least ex- 
pect to find them, are perplexing 5 a circumstance which together 
with the vague manner in which the observations are frequently re- 
corded, and the habit, which in many instances unfortunately pre- 
vailed, namely, of observing the immersion and emersion of the same 
star, on the same occasion, with different telescopes, and the almost 
constant omission to register, if the moon's dark limb, was or was not 
visible, enable us, Mr. South says, to do little more than to state, 
with some appearance of probability, what are not the causes of the 
phenomena. 

The hypotheses advanced as explanatory of the phenomena in ques- 
tion, are then stated : viz. A lively imagination on the part of the ob- 
server :— A spurious disc given to the moon's image by the instrument 
of observation : — A lunar atmosphere : — Irradiation : — And lastly, 
different refrangibilities to which the rays from the moon and star 
are liable, arising from their differences of colour. 

As unfavourable to the first hypothesis, which would refer the 
phenomenon to a lively imagination on the part of the observer, 
Mr. South advances the fact, that ' more than sixty instances of ano- 
maly stand attested by such men as Messier, Troughton, Bouvard, 
Arago and Mathieu ; and that it is rather too much to suppose, that 
all of them are liable to the imputation, which such an hypothesis 
would require. 

The second hypothesis, which supposes a spurious disk to be given 
to the moon's image, might, he observes, be entitled to some consi- 
deration, had refracting telescopes whose object-glasses were not 
achromatic, been solely employed for the observations ; but seeing 
that refractors, long and short, achromatic and non-achromatic j re- 
flectors, newtonian and gregorian, most of which were probably far 
above the rank of good instruments, and some of which certainly 
might be brought forward as the most perfect specimens of optical 
ingenuity, — have all exhibited the anomaly ; there is considerable dif- 
ficulty in receiving the hypothesis j unless indeed we could grant that 
a constant cause should not produce a constant effect. 

The next hypothesis offers a lunar atmosphere as the occasion of 
the apparent projection of a star on the moon's disk. Were this the 
case, its effects would be similar upon all stars of similar colour ; and 

should 



Royal Academy of Sciences of Paris. 301 

should we not see evidence of its existence, in some shape or other, 
at every occultation which occurred I yet, how infinitely few are the 
instances, in which any thing whatever is observable of alteration in 
the star, on the moon's approach to it j indicated by derangement of 
its position, diminution of its splendour, or change of colour. Still it 
must be remembered, such changes do stand on record ; but they are 
either so unsubstantiated, or are so referable to other causes than a 
lunar atmosphere, that we are scarcely warranted in lending ourselves 
to the hypothesis, to which they would conduct us. 

The hypothesis next in order, suggests irradiation as the source 
from which the anomaly is derived. It seems, however, Mr. South 
thinks, incapable of answering the purpose for which it is brought 
forward ; seeing that projections of stars upon the moon's dark 
limb, have been witnessed by Messier, by Maskelyne, by Arago, by 
Mathieu, and by himself. 

That the last hypothesis, — namely, that which supposes the appa- 
rent projection to arise from the different refrangibilities of the rays 
issuing from the star and moon, — is not tenable, Mr. South advances 
the circumstance, that not only Aldebaran and the red stars, are 
liable to the anomaly ; but that stars as remarkable for their white 
light, as is Aldebaran for its red, have exhibited the phaenomenon of 
apparent projection. He also says that, as far as he knows, no instance 
of apparent projection of the planet Mars upon the moon's disk, is at 
present recorded amongst the list of lunar occultations of that planet j 
yet Mars is much more decidedly red than Aldebaran, or than any 
other star which has been observed on the lunar disk. 

Having, as he thinks, shown that the above hypotheses are inade- 
quate to the purpose for which they have been designed, Mr. South 
states that he should not be justified in advancing any hypothesis in 
addition to those which he has combated ; but concludes his paper by 
stating that from the Connoissance des Terns, he finds that the moon's 
path will, during the years 1829 and 1830 furnish several occultations 
of Aldebaran j when it is to be hoped that a phaenomenon, which has 
been so little observed in Great Britain, that if it rested solely on the 
authority of British Astronomers would be scarcely entitled to any 
notice, will not longer furnish an object for their reproach. 

ROYAL ACADEMY OF SCIENCES AT PARIS. 

Feb. 4th, 1828. — Dr. Panquy presented an Essay on a natural 
chemical method. — M. Moreau de Jonnes communicated some de- 
tails relating to the late earthquakes in the Antilles M. Freycinet 

read a letter from MM. Quoy and Gaymard, dated from Tongata- 
bou — MM. Latreille and Dumeril gave a favourable account of a 
memoir presented by Dr. Bretonneau, On the blistering properties 
of some insects of the Cantharides family. — M. Coquebert de Mont- 
bret reported respecting a memoir of M. Auguste Duvau, intitled : 
A Statistical Essay on the department of Indre and Loire, or ancient 
Touraine. — M. Gay-Lussac announced that M. Guimet, assistant- 
commissary in the Powder and Saltpetre Works, had succeeded in 
manufacturing ultramarine, by combining the principles which 

chemical 



302 Royal Academy of Sciences of Paris. 

chemical analysis had discovered to exist in it. This new product 
is richer in colour and more splendid than the natural one. — M. 
Ozenne continued the reading of his paper on the study of delivery. 
— The Academy elected a Commission by ballot, for adjudging the 
prize founded by M. de Monthyon, in favour of him who should ren- 
der an art or trade less unwholesome. — The Commissioners are: 
MM. Thenard, Gay-Lussac, Darcet, Chevreul, and Dulong. 

Feb. 11. — ML Lermier sent Researches concerning the influence 
which the will of man exercises upon inanimate bodies. — M. Julia 
Fontenelle, a letter On the phenomena of the incandescence of 
strontian and barytes. — M. Baehr of Kcenigsberg, a memoir intitled, 
De Ovi Mammalium et Hominis Generi. — M.Beudant gave a favour- 
able account of M. Rozet's geognostic description of the Bas*Boulon- 
nais. — M. Cuvier, on behalf of a Commission, presented an analysis 
of all the specimens which MM. Quoy and Gaymard had sent to 
the Museum of Natural History since the sailing of the Astrolabe : 
these indefatigable observers render themselves increasingly worthy 
of the protection of authority.— M. GeofFroy Saint- Hilaire reported 
respecting the memoir of M. Lisfranc, relating to the Rhinoplastic ; 
the opinions are very favourable. — M. Civiale began the reading of 
a new memoir on Lithotrity. 

Feb. 1 8. — The Minister of the Interior invited the Academy to 
examine the weighing machines made by M. Paret. — M. Tournal, 
Jun. sent a memoir On the geognostic constitution of the basin in 
the environs of Narbonne. — M. Lassaigne sent, by request of the 
Director of the School at Alfort,a molar tooth of an elephant, found 
fifteen feet below the surface, in a mass of sand and flints worked 
near the village of Maison. — M. Levret presented a memoir, intitled 
Des Courbes et des Surfaces semblables. — M. Donne read a memoir 
On the employment of iodine and bromine, as tests of the vegetable 
alkalies. — MM. Saint-Hilaire and Martin read a memoir On the 
anatomy of some parts of the female tortoise. — MM. Legendre, 
Poinsot and Cauchy gave a favourable account of an extremely 
curious memoir very long since presented to the Academy by M. 
Poncelet: this memoir was intitled, Theorie generate des polaires re- 
ciproques. — M. Lassis read the first part of a memoir On the yellow 
fever. 

Feb. 25. — The Minister of War invited the Academy to examine 
M. Longchamp's Theory of Nitrification. M. JLongchamp wrote 
to request that the examination might be confined to the inquiry, 
whether it was advisable to construct artificial nitre-works accord- 
ing to his theory. — M. Jomard communicated some details respect- 
ing Captain Clapperton and Major Laing, whose death had been 
announced. — M. Saint Hilaire made a favourable report on MM. 
Audouin's and Edwards's memoir On the nervous system of the 
Crustaceae. — M.Desfontaines gave a verbal account of M.Chevalier's 
new Flora of the environs of Paris. — M. Lassis concluded the read- 
ing of his memoir On the yellow fever. — M. Comte read anatomico- 
physiological researches on the causes of the superiority of the 
right hand. 

March 3 M. Leymeries sent several treatises respecting the 

causes 



Royal Academy o/Scie?ices of' Paris. 303 

causes of the yellow fever; M. Arago presented from M. Fiedler, 
several vitrified tubes produced by lightning; one of them was 
eighteen feet long. — M. Chevreul requested not to be one of the 
Commission appointed to examine the memoir of M. Longchamp 
on nitrification.— M. Latreille, on behalf of a Commission, gave a 
very favourable account of M. Edwards's memoir On the four un- 
described species of Crustacea?. — M. Savart, in the name of a Com- 
mission requested by the Minister of the Interior, announced that 
there would be no inconvenience in punching M. Paret's weighing 
machines.— M. Coquebert-Montbret gave a verbal account of se- 
veral statistical researches by M. Cesar Moreau, vice-consul of 
France in London, relating to the finances of Great Britain. 

March 10.— M. Vauquelin presented a memoir by M. Farro On 
the copper extracted from vegetables — M. Raspail presented several 
plates relating to a memoir which he read in the month of Septem- 
ber last. — MM. Dumeril and Magendie, named by the Academy, 
at the request of M. Malbouche, to take cognizance of the pro- 
cesses received from America, and which, according to M. Mal- 
bouche, form a certain method of curing stammering, announced 
that the method succeeds in the greater number of cases. — M. Am- 
pere gave an unfavourable verbal account of a publication by M. 
Opoix, respecting the sensations of sound and light. — There were af- 
terwards read,— a memoir by M. Peclet, On the passage of hot air 
through pipes; — a memoir by M.Nicollet, On the latitudes of 
Barcelona and Montjouy, ascertained by M. Mechain ; — a memoir 
by M. Raspail, On the granules of pollen ; — and a memoir On the 
mechanism of the voice, by M. Begin. 

March 17. — M. Deleau gave a written account of the progress of 
four deaf and dumb children, which had been put under his care. — 
M. Roche presented a memoir relating to the laws according to 
which the elastic force of vapour increases with the temperature. — 
M. Gendrin announced that he had obtained very good results in 
the employment of iodine in the gout. — An anonymous correspon- 
dent announced that he had discovered an infallible plan for stopping 
the leakages in the Tunnel under the Thames. — M. Brongniart read 
a letter from M. Acosta, respecting the earthquake which had de- 
stroyed a great part of the city of Popayan.— M. Warden communi- 
cated a note respecting two islands recently discovered in the Pa- 
cific Ocean, by Captain Joshua Coffin. — M. Arago replied to some 
doubts which had been expressed respecting M. Fiedler's vitrified 
tubes; and afterwards gave an analysis of an English memoir, which 
the President had sent him, respecting two aurorae boreales, observed 
in America. — M. Dumeril gave a very favourable account of the 
anatomical researches which MM. Martin and Isidore Saint- Hilaire 
presented respecting the anatomy of the tortoise and the crocodile. — 
M. Fourier presented a memoir On the conducting power of bodies. 
— M. Hericart de Thury read a notice respecting an overflowing 
spring, lately obtained by boring, in the park belonging to Madame 
Groslier at Epinay. — M. Dutrochet read additional researches on 
endosmosis and exosmosis. 

March 



304 Royal Academy of Sciences of Paris. 

March 24. — M. Poinsot presented a note on the formulae, by the 
aid of which the invariable plan of our system is determined, regard 
being had to the rotary motion of the sun. — M. Cuvier exhibited a 
portion of a fossil jaw recently discovered in the gypsum of Mont- 
martre, analogous only to that of an animal of Van pieman's Land^ 
— Dr. Foville presented his researches On the anatomy of the brain. 
— The Academy afterwards heard a verbal report by M. Damoiseau 
On the chronological researches of M. Eustache Oliveri ;■— a memoir 
On vision, by M.Vallee ; — a memoir by M. Becquerel, On the effects 
of heat upon the tourmaline and bad conductors of electricity. 

March 31. — The Academy received a sealed packet from M. Ca- 
ventou, containing the results of some experiments on vegetable 
chemistry ; — a letter from M. Coulier, On the means of preventing 
the falsification of writings; — a note by M. Serullas, On the sweet 
oil of wine, oxalic aether, and bicarburetted hydrogen ; — an extract 
of a memoir by M. Gaudin On colours ; — an analysis of M. de Fer- 
raont's work On the circulation and on respiration ; — a memoir by 
M. Vallot, On some ancient descriptions and drawings of the giraffe ; 
—a notice by M. Thirria, On the grottos of Echenoz and Fouvent 
(Haute-Saone), and the fossil bones which they contain. — M. Ma- 
thieu, in the name of a Commission, reported on the memoir of M. 
Alexandre Roger, concerning the height of Mont-Blanc. — M. Beu- 
dant began the reading of a memoir On the chemical composition 
of mineral substances. 

April 7. — The Academy received a memoir On the equilibrium 
of solid bodies, by MM. Lame and Clapeyron ;— a memoir by M. 
Duhamel, On the mathematical theory of heat; — a note by M.Braun, 
On the possibility of directing air-balloons; — a letter from M. Co- 
rencez, who offered himself as a candidate for the vacant place of 
member in the section of geometry ; — a memoir by M. Farreau, On 
the presence of copper in vegetables, and the blood. — M. Geoffroy 
Saint-Hilaire stated that the anatomical facts discovered by his son 
and M. Martin, had been completely illustrated by examining yes- 
terday a dead tortoise at the Menagerie. — M. Chevreul read a me- 
moir On the influence which two colours may exert upon each 
other when seen together. 

April 14. — The Academy received a sealed packet from MM. 
Chevalier and Langlume, containing an account of some improve- 
ments in lithographic processes ; — the results of meteorological ob- 
servations made at Alais, in 1827, by M. d'Hombres-Firmas ; — an- 
other letter from M. de Coulier, On the means of preventing the 
falsification of writings; — a memoir on the Euripode by M.Guerin ; — 
a memoir by M. Corancez, On the integration of equations, &c. ; — a 
note from M.Tournal, On the sulphur which had been found in the 
gypseous fresh-water formation at Narbonne. — M. Beudant read a 
notice on vitrified tubes. — M. Coquebert announced that, according 
to M. Pentiand, there are in America several higher mountains than 
Chimborazo. — M. Geoffroy Saint-Hilaire gave an unfavourable 
account of M. Vallot's memoir On the giraffe. — M. Maisonabe ex- 
hibited a boy of twelve years old, who had club feet ; one of them 

had 



Royal Academy of Sciences of Paris. 305 

had already been subjected to treatment : M. Maisonabe will pre- 
sent him again when cured. — M. Arago, in the name of a Com- 
mission, reported on M. Bunten's modification of the barometer. — 
Mi Beudant continued the reading of his paper On the analyses of 
minerals. — M. Heron de Villefosse communicated the results of 
statistical researches on iron. 

April 21 The Academy received : Considerations on light and 

colours, by Baron Blein ; — a memoir by M. J. Cambessedes, On 
the families of the Ternstromiacece and Guttiferce; — a memoir by 
M. Warden, On the civilization of the Cherokees ; — Researches on 
the harvests of France formerly and at present, by M. Benoiston de 
Chfiteauneuf. — MM. Arago and Savart announced that the me- 
moir of M. Braun On the means of directing air-balloons, contained 
nothing worthy of serious criticism. — M. Poisson read a memoir 
On the equilibrium and motion of elastic bodies. — M. Latreille gave 
a very favourable account of M. Guerin's memoir On a new genus 
of Crustacea, called Euripode. 

April 28. — The reading of the minutes of the last sitting occa- 
sioned various explanations between MM. Poisson, Navier, and 
Cauchy, on the subject of differential equations proper to represent 
the internal motions of elastic bodies. — The Academy received 
A claim from M. Meller on the subject of M. Maisonabe's com- 
munication respecting the cure of club feet ; — A sealed packet from 
M. Deleau, marked : Theory of stammering ; — A letter from M. 
Despretz, relating to some fusible white crystals, volatile at a low 
temperature, which he had noticed during the decomposition of bi- 
carburetted hydrogen subjected to a strong heat ; and on the dimi- 
nished density of iron, copper and platina, during the decomposition 
of ammonia by these metals. After the reading of this letter, M. 
Savart stated that he had himself long since found, in concert with 
M. Persoz, the last results obtained by M. Despretz. Several mem- 
bers of the Academy present at the sitting, asserted that M. Savart 
had mentioned it to them. — M. Delpech communicated several facts 
relating to rhinoplasty, to the disease known by the name oftrichyasis, 
&c. &c. — Baron Blein read the memoir on light and colours, which 
he presented at the last sitting. — M. Warden communicated some 
information respecting the American colony established at Liberia, 
on the coast of Africa. — A Commission was appointed to propose 
a mathematical prize for 1830 ; it was composed of MM. Legen- 
dre, Fourier, Poisson, Lacroix, and Poinsot. — M. Longchamp read 
an additional notice on his theory of nitrification. A member, M. 
Arago, observed that M. Longchamp's memoir contained state- 
ments totally devoid of science ; that he imagined he had even 
heard offensive personalities against a very distinguished foreign 
philosopher. He invited the President to listen attentively to the 
remainder of the memoir, and to decide, whether he ought not to 
stop the reading of it, in conformity with an article of the regula- 
tions. 

Prizes adjudged "by the Royal Academy of Sciences for the year 1828. 

On examining the essays, it was found that no one of them suf- 

New Scries. Vol. 4-. No. 22. Oct. 1828. 2 R ficiently 



306 Intelligence and Miscellaneous Articles, 



•a 



ficiently answered to the terms of the question, to be entitled to the 
grand mathematical prize. 

Astronomical Prize, founded by M. Lalande. — The medal was 
adjudged to MM. Carlini of Milan, and Plana of Turin, authors 
of a work On geodesical and astronomical observations, &c. 

Prize for experimental Physiology, founded by M. Montyon. — A 
gold medal was adjudged to M. Dutrochet, for his discovery of the 
phenomena which he has detailed under the name of Endosmosis. 
— Another medal was given to MM. Andouin and Edwards, for their 
experiments and observations upon the circulation and respiration 
of the Crustacea. 

Prize for discovering the means of rendering an art or trade less 
unhealthy, founded by M. Montyon. — This prize was not awarded. 

Prize founded by M. Montyon, for improving the healing art. — To 
M. Chervin, for his work on the yellow fever, 10,000 francs were 
awarded. 5000 francs to Baron Heurteloup, for his important im- 
provements and ingenious instruments introduced this year in li- 
thotrity. To Dr. Gruethuisen, for his works on the same subject, 
a gold medal of the value of 1000 francs. 

Statistical Prize founded by M. Montyon.— This was awarded to 
M. Thomas, for his statistical account of the Isle of Bourbon. 



LI II. Intelligence and Miscellaneous Articles, 

CHLORINE IN BLACK OXIDE OF MANGANESE. 

IN a former number of the Phil. Mag. and Annals I have noticed 
a paper published by Mr. MacMullen in the Institution Journal, 
the object of which was to prove that the native black oxide of man- 
ganese contains chloric acid. In my remarks I supposed I had 
proved that the source of chlorine was chloride of lime, which I 
found in all the specimens of peroxide of manganese submitted to 
examination. Mr. MacMullen has replied to my observations, and 
contends for the accuracy of his experiments and the inferences de- 
duced from them. The only answer I think it necessary to give, is 
the observation of Dr. Turner printed in the Phil. Mag. for Au- 
gust last. " It is the accidental presence of the muriates which gives 
rise to the disengagement of chlorine when sulphuric acid is added 
to some of the native oxides of manganese, and which induced 
Mr. MacMullen to regard chloric acid as a constituent of these 
ores. For the correction of this error we are indebted to Mr. Richard 
Phillips*, with whose observation my own experiments correspond ; 
— none of the native oxides yield a trace of chlorine on the addition 
of sulphuric acid, provided the muriates have been previously re- 
moved by washing." 

In the Institution Journal for April last, Mr. James F. W. John- 
ston has advanced opinions respecting some compounds of manga- 
nese, which are almost as extraordinary and quite as groundless as 

* Phil. Mag. and Annals, N.S. vol. i. p. 313. 

those 



Intelligence mid Miscellaneous Articles. 307 

those of Mr. MacMullen. I shall not notice all Mr. Johnston's 
statements ; the correctness of the first two I admit ; the third and 
fourth are as destitute of accuracy as the fifth, which is as follows: 
— " I threw down a pure carbonate from a pure muriate of manga- 
nese, obtained by Faraday's process. This was dried and partially 
decomposed by heating in an oven ; with diluted sulphuric acid it 
gave also the smell of chlorine." 

M From these experiments," continues Mr. Johnston, " we may 
legitimately conclude, first, that Mr. MacMullen was correct as to 
the fact of the emission of chlorine from the native oxide, which 
Mr. Phillips has called in question, for it is given off by artificial 
oxides, into which no trace of a muriate could possibly enter." 

If Mr. Johnston had read my remarks upon Mr. MacMullen's 
paper, he would have found not that I called in question the fact of 
the emission of chlorine from the native oxide, but on the contrary 
that I admitted and explained it; nor can I discover the accuracy 
of the reasoning by which it is attempted to be proved, that the na- 
tive peroxide of manganese must yield chlorine, because it is given 
off by the artificial peroxide, even admitting this to be a fact. 

I assert, however, and every chemist will readily admit the cor- 
rectness of my statement, that pure carbonate of manganese does 
not yield chlorine by the action of acids. I poured muriatic acid 
upon perfectly white and moist carbonate of manganese ; no smell 
of chlorine was perceptible, and litmus paper was reddened instead 
of having its colour destroyed. 

When, however, carbonate of manganese is dried, a portion of it 
is decomposed, oxygen being absorbed and carbonic acid evolved ; 
and if muriatic acid is added to this mixture, chlorine is readily ob- 
tained, mingled with carbonic acid : this, however, will not account 
for the evolution of chlorine when sulphuric acid is employed to de- 
compose the carbonate. But there are two modes of accounting 
for its production : first, if the precipitate be not sufficiently washed 
it will contain chloride of potassium or sodium, derived from the 
union of the base of the precipitating alkali with the chlorine of the 
muriate of manganese; or, which I have repeatedly found to be the 
case, a submuriate of manganese is formed ; and sulphuric acid act- 
ing upon a mixture of carbonate, per- or deut-oxide and submuriate 
of manganese would readily occasion the evolution of chlorine for 
the disengagement of which Mr. Johnston finds it so difficult to 
account. R. P. 

BROWN OXIDE OF CHROMIUM. 

This compound may be formed by mixing a solution of chromate 
of potash with protochloride of chromium, or by boiling chromic 
acid with protoxide of chrome; when the brown oxide obtained is 
digested with acetate of lead, chromate of lead and acetate of the 
protoxide of chrome are formed. Potash also converts it into 
chromic acid, and green oxide of chrome. Arsenic acid, carefully 
added, produces arseniate of chrome and chromic acid. 

The brown precipitate produced by mixing chromate of potash 
and chloride of chromium, is decomposed by being repeatedly washed 

2 R2 



308 Intelligence and Miscellaneous Articles. 

with water, especially if hot ; chromic acid' is removed, and green 
oxide of chrome remains. Chromate of chromium is decomposed 
in the same manner. 

If chromate of ammonia be heated gradually to the point of de- 
composition, the salt is decomposed suddenly, pure deutoxide re- 
mains, which dissolves readily in concentrated acid. This oxide 
has been mistaken for a combination of protoxide and chromic acid. 
If at the moment of decomposition the temperature be suddenly 
raised, a luminous appearance is produced. Chromic acid dissolves 
the hydrate or the carbonate of chrome readily, and a dark brown 
solution is produced, which when evaporated leaves a brittle resi- 
nous-looking mass, which is deliquescent and soluble in alcohol. 
— M. Mans. Annales de Chimie, xxxvi. 216. 



MASSES OF NATIVE PLATINA. 

One by Humboldt from Peru, now in the Berlin museum, weight 
1083 grains. Another from America in 1822, weighing 11,640 
grains, now in the Madrid museum. A third within a few months 
from the Uralian mountains, deposited in the museum at St. Peters- 
burgh, weighing above 81,000 grains. — Jamesons Journal. 



PREPARATION OF TITANIC ACID. 

The following is the method recommended by M. H. Rose : — 
Pulverize and wash titaniferous iron, expose it in a porcelain tube 
to the action of dry sulphuretted hydrogen gas, at a very high tem- 
perature. The oxide of iron is reduced and converted into sul- 
phuret, whilst the titanic acid suffers no change : the product when 
cold is to be digested in concentrated muriatic acid ; much sulphu- 
retted hydrogen is given out, and sulphur is deposited ; this mixing 
with the titanic acid, which the heat has rendered insoluble in the 
muriatic acid, the acid becomes grey. The acid is to be washed, 
dried and ignited, to expel the sulphur. 

If the operation were to terminate here, the titanic acid would 
still contain some iron, and become red by calcination. The reason 
of this is, that the sulphuret of iron formed being in considerable 
quantity, agglutinates by heat with the titanic acid, and prevents the 
centre of the mass from being perfectly attacked by the sulphuretted 
hydrogen. On this account the operation must not be continued 
until water ceases to be disengaged, which would render it very 
long, but it must be stopped at the moment the water begins sen- 
sibly to diminish. The titanic acid is therefore to be exposed a 
second time in the porcelain tube to the action of sulphuretted hy- 
drogen, and after having been treated with muriatic acid, well washed 
and ignited, it becomes perfectly white and pure. All varieties of 
titanic acid, which contain but little iron, and even rutile, may be 
treated by this process. 

This process appears to me shorter and less expensive than that 
which I have before published, and which consists in dissolving tita- 
niferous iron in muriatic acid, adding tartaric acid to the solution, 
and precipitating the iron by hydrosulphuret of ammonia. Not only 



Intelligence and Miscellaneous Articles. 309 

is the newer process less complicated and expensive, but I have 
never yet found tartaric acid free from lime, and this base remains 
combined with the titanic acid. If during the treatment of the tita- 
niferous iron by the sulphuretted hydrogen the heat is not very 
strong, the titanic acid obtained will render the washings milky, and 
will partly pass through the filter ; but this will not occur if the heat 
be sufficiently great. 

Hydrogen gas does not succeed so well as sulphuretted hydrogen : 
the oxide is indeed reduced, but the titanic acid obtained by this 
process is always ferruginous. Muriatic acid does not give a better 
result. 

The time occupied in the operation now described may be short- 
ened by fusing the titaniferous iron with sulphur in an earthen cru- 
cible. The mass is to be treated with concentrated muriatic acid, 
which removes much of the iron ; but some remains with the titanic 
acid, and nearly as much as in rutile ; by treating this impure acid 
with sulphuretted hydrogen as above described, it is obtained pure 
at one operation. — Annates de Chimie, xxxviii. 133. 

ARTIFICIAL FORMATION OF UREA. BY M. F. WOHLER. 

M. Wohler has already shown, that when cyanogen is made to 
act upon solution of ammonia, there are obtained, besides several 
other products, oxalic acid, and a white crystalline substance, which 
occurs also whenever the attempt is made to combine cyanic acid 
with ammonia by double decomposition. On prosecuting his in- 
quiries, M. W. found that by the combination of cyanic acid with 
ammonia, urea was formed ; this is a remarkable fact, as offering the 
artificial formation of organic matter, and even animal matter, by 
means of inorganic principles. 

The white crystalline substance is most readily obtained by de- 
composing cyanate of silver by a solution of muriate of ammonia, 
or cyanate of lead by liquid ammonia ; it is colourless, transparent, 
and crystallizes in the form of small rectangular quadrilateral prisms 
without any distinguishable pyramids. Neither potash nor lime 
evolves any trace of ammonia from this substance. Acids do not, as 
with the cyanates, disengage either carbonic or cyanic acid: it does 
not, like the cyanates, precipitate the salts of lead and silver ; it is 
therefore evident that it contains neither ammonia nor cyanic acid. 
Most acids have no marked action on this substance, but the nitric 
acid when added to a concentrated solution gives a precipitate in 
the form of brilliant scales. These crystals are extremely acid, and 
were at first supposed to be a peculiar acid, but when decomposed 
by bases, nitrates of those bases were obtained ; and by alcohol, 
the white crystalline matter was obtained unchanged in its proper- 
ties : these properties, when compared with those of pure urea ob- 
tained from urine, indicated that this substance, or cyanate of am- 
monia, is absolutely identical with urea ; a conclusion which is 
strengthened by the properties assigned to urea in the writings of 
Proust, Prout, and others. M. Wohler states some facts with re- 
spect to urea (and also with regard to this artificial substance, ) which 

he 



810 Intelligence and Miscellaneous Articles. 



•6 



he says have not been previously noticed. When natural or artifi- 
cial urea is decomposed by heat, there is produced, besides a large 
quantity of carbonate of ammonia, towards the end of the operation 
a smell of cyanic acid resembling that of acetic acid, precisely as 
occurs during the distillation of cyanate of mercury or uric acid, 
and especially urate of mercury. By the distillation of urea, a 
white substance is also obtained, the properties of which are under 
examination. 

If cyanate of ammonia be similar to urea, then the composition 
of the former as obtained by calculation should resemble that of 
the latter ; assuming one atom of water in cyanate of ammonia, as 
in all ammoniacal salts which contain any, and adopting Frout's 
analysis of urea as the most correct, it consists of 

Azote 46-650 4 atoms. 

Carbon 19-975 2 

Hydrogen 6-670 8 

Oxygen 26-650 

99-945 
Cyanate of ammonia should consist of 56-92 cyanic acid, 28-14 
ammonia, and 1474 water, which give as its elements : 

Azote 46*78 4 atoms. 

Carbon 20-19 2 

Hydrogen 6-59 8 

Oxygen 26-64 

By the combustion of cyanic acid by means of oxide of copper, two 
volumes carbonic acid gas, and one volume of azote are obtained; but 
by the combustion of cyanate of ammonia, there should be procured 
equal volumes of these gases, which is what Prout actually found in 
the combustion of urea. — Annates de Chimie, April 1828. 



NATIVE IRON IN THE UNITED STATES. 

In the second volume of the Phil. Mag. and Annals, at p. 71, 
will be found an account of a variety of native iron found on Ca- 
naan mountain in Connecticut, extracted from Silliman's Journal. 
In the last Number of that Journal, which we have lately received, 
are the following particulars of the situation in which the iron was 
found, and of the probable existence of a mass of native iron at that 
spot. They are contained in Prof. E. Hitchcock's " Miscellaneous 
Notices of Mineral Localities." 

" Sept. 6th, Canaan, Connecticut. — This is an interesting region, 
both to the geologist and mineralogist. We were attracted thither, 
principally by the hope of discovering the spot from which the na- 
tive iron was obtained, that was recently announced in this Journal. 
We called upon Major Burrall, who, in search of the iron which he 
formerly obtained from this mountain, had recently visited it again, 
in company with his son, Mr. Wm. Burrall. a graduate of Yale- 
College, and Dr. Reed. Major B. not being able to go with us to 
the spot, the two other gentlemen just named, conducted us. About 
two miles north of the meeting-house, in the south parish in Canaan, 



Intelligence and Miscellaneous Articles. 311 



'.b 



is a precipitous mountain, nearly a thousand feet in height ; and it 
was on its top, and near the western edge, that the native iron was 
found, — not three years ago as stated in this Journal, but as Major 
Burrall informed us, sixteen or seventeen years since. At the base 
of the mountain is limestone, succeeded by an aggregate of quartz 
and mica, which appears to be one of the varieties of Dr. Maccul- 
loch's quartz-rock. The top of the mountain, however, is well cha- 
racterized mica-slate, containing small imperfect crystals of magnetic 
iron-ore, sparinglydisseminated. On the top of the mountain we came 
to a pond, perhaps sixty or eighty rods across ; and on the south- 
west margin of this pond is the spot where, as well as Major Bur- 
rall can recollect, he obtained the specimens in question. At this 
spot he found his compass liable to so great a variation that it was 
useless; and on examining the rocks for the cause, he found the spe- 
cimens that have excited so much interest. Mr. Burrall, junior, 
took his father's compass with him, on our present excursion, and 
attempted to run over the same line which his father pointed out 
to him, as the one upon which he experienced so much difficulty. 
This line runs nearly east and west, just upon the southern margin 
of the pond ; and we found that where it approaches the nearest to 
the pond, there was a variation of 30°, as shown by back objects. 
On setting the compass only two or three rods backwards or for- 
wards on the line, however, the variation almost entirely vanished. 
This showed us that the magnetic mass, that produced the varia- 
tion, could not be far removed from the line, either north or south ; 
for had it been at a considerable distance, the removal of the com- 
pass a few rods either east or west, could not materially have af- 
fected the variation ; since the radius of a large circle for a consi- 
derable number of degrees, differs so little from the secant. We 
removed the compass one or two rods to the north, and ran a line 
parallel to that above named, so as even to enter a little distance 
into the pond, where the water is highest. Here the variation was 
even greater than upon the first line ; so that the attracting mass 
must lie north of that first line. Probably it lies just in the edge of 
the pond ; and I have no hesitation in saying, that a circle, described 
with a radius of two rods, upon the point where the greatest varia- 
tion was noticed, would embrace the ferruginous mass that here 
disturbs the needle ; nor is there much reason to doubt but that 
mass is native iron. And whoever has observed how large a mass 
of iron it requires to turn aside the needle of a compass, at the di- 
stance of one or two rods, will presume that the mass here depo- 
sited must be a large one. The spot I have been describing is co- 
vered with trees and thick underbrush, and the moss and rubbish 
almost entirely hide the rocks underneath. The bottom of the pond 
is sphagnous ; and perhaps it might be necessary partially to drain it, 
which is not difficult. Whoever will be at the trouble and expense 
of removing the brush, moss and soil, at this spot, under the direc- 
tion of Mr. Burrall, or Dr. Reed, will, I have little doubt, be abun- 
dantly rewarded by the discovery of a mass of native iron." 

" On seeing this pond, and considering this locality of native iron 

on 



312 Intelligence and Miscellaneous Articles. 

on its margin, the inquiry forces itself on the mind, — may it not be 
the crater of an extinct volcano? But I could perceive not the 
least indication of any igneous action." 

" Major Burrall presented me with a small specimen of the native 
iron, whose characters correspond exactly to those given in the 
12th volume of this Journal ; but it furnishes no additional infor- 
mation." — SiUimaris Journal^ vol. xiv. p. 223. 

In the review of Prof. Olmsted's official " Report on the Geology 
of North Carolina," given in the same Number, p. 235, occurs the 
subjoined notice of specimens of native iron from that state. 

** One of the specimens of iron-ore sent to Prof. Olmsted, from 
the slate-formation, or gold-region, proved to be native iron. An- 
other was afterwards discovered that weighed twenty-seven pounds, 
and a part of it was wrought by the blacksmiths." — p. 31 and 108. 

An account of the dightly arseniuretted native iron of Bedford 
county, Connecticut, (also extracted from Silliman's Journal,) will 
be found in the present volume of the Phil. Mag. and Annals, 
p. 73. 

FOSSIL REPTILES. 

M. Jaeger, in his work Vber die Fossile Reptilien, tvelcke in Wur- 
temberg aufgefunden Ivor den sind, Stuttgart, 1828, gives the follow- 
ing list of fossil reptiles found in the Wirtemberg rocks : 
" Crocodilus Bollensis. 
Geosaums Bollensis. 
Ichthyosaurus platyodon. 
Ichthyosaurus communis. 
Ichthyosaurus intermedins. 
Ichthyosaurus tenuirostris. 
L Plesiosaurus ? 
In the variegated Marl, r Cylindricodon. 

( Kewper. ) \ Cubicodon. 

T . , c,, , f Massodonsaurns. 

In Aluminous Shale. ( S alamandroides giganteus. 
r Plesiosaurus. 

In Muschelkalk J Ichthyosaurus. 

I A third Reptile. 

H.T.D.B. 



In the Lias <( 



METHOD OF PRESERVING FUNGUSES. 

Mr. Cooke, surgeon (Trinity Square, Tower Hill), having been 
very successful in his endeavours to preserve anatomical preparations 
in salt and water, was requested to try to preserve in the same way 
a specimen of Clavaria muscoides (Sowerby's English Fungi), sup- 
posing that it might answer for funguses of some kinds. 

Mr. Cooke in a written account says : " I put it into brine a little 
below saturation, suspending it by a delicate thread of silk, and 
closing the bottle by means of glass. Since that time it has re- 
mained in the solution, and with the exception of having become a 
little deeper in colour it is unchanged. As spirits are not only ex- 
pensive, 



Intelligence and Miscellaneous Articles. 313 



pensive, but usually deprive plants of all colour, the discovery of a 
cheap and effectual solution for the preservation of plants is a de- 
sideratum." 

The specimen was gathered at the latter end of October 1826, 
and was presented to the Linnaean Society in May last, with an ac- 
count of the process. As many species of funguses may be expected 
to appear at the latter end of this month and in the next, persons 
who are desirous of trying the before-mentioned method of preserv- 
ing such vegetables, will no doubt have an opportunity of so doing. 

Sept. 17, 1828. i B. M. Forster. 

DIFFERENCE OF LONGITUDE BETWEEN PARIS AND GREENWICH. 

Captain Kater in his account of trigonometrical operations for 
determining this difference, (published in Part I. of the Phil. Trans, 
for the present year,) observes, p. 193, that the quantity 2° 30' 17"'73, 
obtained by those operations, " converted into time is 9 m 21 s# 18, 
differing only S *28 in defect from the admirable results obtained by 
the operations with fire-signals, reported in the Phil. Trans, for 
1826, by Mr. Herschel." 

It may possibly save trouble to some future inquirers, to state, 
that Captain Kater here refers to the results of Mr. Herschel's ope- 
rations, as corrected by Mr. Henderson in the Phil. Trans, for 1827, 
p. 295 (see also Phil. Mag. and Annals, N. S., vol. ii. p. 142), which 
give 9 m 21M6, or 9 m 2i s *5, to the nearest tenth of a second, instead 
of 9 m 21 s -568, and 9 m 2P-6, as given in Mr. Herschel's paper. 

Mr. Ivory also, in his paper On the measurement of degrees per- 
pendicular to the meridian, in the last Number of the Phil. Mag. and 
Annals, refers to the same determination as corrected by Mr. Hen- 
derson ; though he, like Captain Kater, refers only to the original 
paper in the Phil. Trans, for 1826, without mentioning Mr. Hen- 
derson's recomputation in the same work for 1 827. 



FIGURE OF THE CELLS OF THE HONEYCOMB. 

To the Editors of the Philosophical Magazine and Annals. 
Messieurs, 

En faisant des recherches surles alveoles des abeilles *, j'ai recueilli 
les details suivans, qui peuvent servir a l'histoire du probleme pro- 
pose par Reaumur. 

1°. Le professeur Cramer, de Geneve, envoy a a Koenig, en 1739, 
une solution qui ne differait pas de la sienne, etant appuyee comme 
elle sur le calcul de l'infini. Toutes les deux sont perdues. 

2°. Le Pere Boscowich, sans avoir connaissance de la methode de 
Maclaurin, resolut comme lui le probleme par la consideration des 
maxima et minima. On trouve cette solution dans ses remarques sur 
lepoeme de Stay. 

3°. Enfin, Lhuilier, de Geneve, a resolu aussi le probleme, par 
un procede plus simple encore que celui de Maclaurin, puisqu'il 
arrive au meme r&sultat, sans employer la consideration des maxima 
et minima : ce n'est plus qu'une question de geomStrie commune. 

* See p. 20 and p. 233 of the present volume of the Phil. Mag. and 
Annals. — Edit. 

New Series. Vol. 4, No. 22. Oct. 1 828. 2 S Vos 



314 Intelligence and Miscellaneous Articles* 

Vos lecteurs, pour sen assurer, peuvent recourir aux Memoires de 
FAcademie de Berlin, annee 1781. Fayolle. 



on varignon's method of solving equations of the 
second degree. by m. fayolle. 
To the Editors of the Philosophical Magazine and Annals. 
Messieurs, 
La methode que vous avez inseree dans votre dernier numero, 
pour la resolution des Equations du second degre, m'en a rappelle 
une de Varignon qui est encore plus simple, et qui s'applique aux 
equations du troisieme degre. Elle est si facile (disait Fontenelle), 
qu'on est tout surpris que Varignon l'ait trouvee le premier. 
La voici en peu de inots : 

Soitz*+p z + q = 0. 
Faisons z = x— y ; alors 

z % — x % — 2xy+y* = x*— 2xy + 2y*— y* 

= x i —2yz—y*; 
Et par consequent, z°--\-2yz-{-y* \ _ n 

—x* > ~" 
Laquelle comparee terme a terme avec la proposee, donnera 
1°. pz = 2yz, ou y = %p, 
2°. q=y q -x*> ou q = ±p* — x\ 
D'ou resulte x — + x/^p* — q 



Done z = x — y = — ip ± V \p % — q. 
Si Ton avait z 1 — pz~\-q = 0, 
II faudrait prendre z = x + y. 

Cette methode s'applique avec la meme facilite a l'equation du 
troisieme degre z 3 + p z + q = 0, 

Laquelle est degagee du second terme. 

Ce 16 Aug. 1828. Fayolle. 

MINERALOGICAL LITERATURE. 

1. Dr.Naumann, professor in the Mining Academy of Freiberg, 
has published Lehrbuch der Mineralogie ( Treatise on Mineralogy), 
Berlin, 1828, by A. Rucker, in 8vo. This treatise, by a scholar of 
the celebrated Professor Mohs of Vienna, is one of the best on that 
science. The crystallographic method of Professor Naumann is 
eclectic in reference to those of Mohs and Weiss, and is very good ; 
the system is established according to the physical and chemical 
characters of minerals. He describes a multitude of varieties of 
crystals with the assistance of 556 figures. In general the work is 
very classical, and deserves to be recommended to mineralogists. 

"2. Dr. Charles Hartmann, Mining-officer in the service of his 
Highness the Duke of Brunswick, has published Worterbuch der 
Mineralogie und Geognosie y (Dictionary of Mineralogy and Geology), 
Leipsic, by Brockhaus, 8vo. This work gives a description of all 
known minerals and rocks in alphabetical order, and contains an 

introduction 



Intelligence and Miscellaneous Articles. 315 

introduction to mineralogy and geology, with the history and lite- 
rature of the sciences in systematical arrangement. In reference 
to the crystallography, Dr. Hartmann pursues the methods of Pro- 
fessor Mohs and of Professor Weiss. This work merits the par- 
ticular notice of all mineralogists, and also travellers, because the 
size of the book is not great, and the type very small. A German, 
an English, a French, and an Italian index facilitate the use of the 
book, and 312 figures illustrate the forms of the crystals. 

3. Dr. Hartmann has also published Vorlesungen icber Minera- 
logie, fyc, — (Lectures on Mineralogy, particularly for Schools,) &c. 
Ilmenau, by Voigt, 8vo. This elementary treatise is strongly re- 
commended to young men who study the natural history of mine- 
rals, and to lecturers in schools. As in the elementary introduction 
of Mr. Phillips, the crystalline forms of minerals are illustrated with 
wood-cuts printed along with the text. 

SCIENTIFIC BOOKS. 

Just published. 

No. I. of Zoological Researches and Illustrations; or Natural 
History of Nondescript or imperfectly known animals, in a series of 
Memoirs : illustrated by numerous figures. By John V. Thomp- 
son, Esq., F.L.S., Surgeon to the Forces; author of A memoir on 
Pentacrinus Europceus. 

This first Number contains the following memoirs: 1. On the 
metamorphoses of the Crustacea, and on the animals forming the 
genus Zoea, exposing their singular structure, and demonstrating 
that they are not, as has been supposed, a peculiar genus, but the 
larvae of Crustacea : with two Plates. 2. On the genus Mysis, or 
Opossum Shrimp ; also with two Plates. 

The author of this novel contribution to the stores of zoological 
science, has we understand devoted much time and exertion to the 
collection and preparation of materials for the work. They are 
wholly original, and the results of observation on animals of every 
class, but more especially on the marine Invertebrata, in both he- 
mispheres of the world. 

No. II. will be published in January ; and the succeeding Num- 
bers at intervals of three or four months. 

Elements of Algebra. By Robert Wallace, A.M., late Ander- 
sonian Professor of Mathematics, Glasgow. 

A Circular, explanatory of Skene's patent as applicable to steam - 
navigation, and undershot water-mills. 

No. II., for the year 1829, of the " Enigmatical Entertainer and 
Mathematical Associate." 

In the Press. 
An American reprint of Mr. Bakewell's new and enlarged edition 
of his " Introduction to Geology" is announced, under the super- 
intendence of Professor Silliman. 

A second edition, considerably enlarged, of Mr. De la Beche's 
Tabular and Proportional View of the Tertiary and Secondary Rocks. 

2S2 list 



316 Intelligence and Miscellaneous Articles. 

LIST OF NEW PATENTS. 

To G. Stratton, of Frederick-place, Hampstead Road, for an im- 
provement in warming and ventilating buildings. — Dated the 28th of 
August 1828. — 6 months allowed to enrol specification. 

To Granville Sharp Pattison, of Old Burlington-street, esquire, 
for a method of applying iron in the sheathing of ships, and of applying 
iron bolts, spikes, nails, and other fastenings in ships and other vessels. 
— 4th of September. — 6 months. 

To J. Seaward and S. Seaward, of the Canal Iron-Works, Poplar, 
for a new method for propelling carriages on roads, and also ships 
and other vessels on water.— 4th of September. — 6 months. 

To C. Sanderson, of Park Gate Iron-Works, near Rotherham, York- 
shire, for a new method of making sheer steel. — 4th of September. 
— 2 months. 

To Admiral S. Brooking, of Plymouth, for his new mode of making 
sails of ships and other vessels. — 4th of September. — 6 months. 

To J. Robertson, of Limehouse Hole, Poplar, for improvements in 
the manufacture of hempen rope or cordage.-— 4th of September. — 
6 months. 

To W. Bell, of Lucas-street, Commercial Road, Middlesex, for his 
improved methods for filtrating water and other liquids. — 4th of Sep- 
tember. — 6 months. 

To W. Farish, Jacksonian Professor in the University of Cambridge, 
for his improved method of clearing out water-courses. — 4th of Sep- 
tember. — 6 months. 

To T. R. Williams, of Norfolk-street, Strand, for improvements in 
the making of hats, &c, and in the covering of them with silk and 
other materials with the assistance of machinery.— 1 1th of September. 
— 6 months. 

To T. Minikew, of Berwick-street, for an improvement in the 
making of chairs, sofas, beds and other articles of furniture for similar 
purposes, and also of travelling and other carriages for personal use. 
— 1 1th of September. — 2 months. 

To J. B. Neilson, of Glasgow, for the improved application of air 
to produce heat in fire-forges and furnaces where bellows or other 
blowing apparatus are required. — 1 1th of September. — 6 months. 

To L. W. Wright, of Mansfield-street, Borough Road, Surrey, for 
improvements in machinery for making screws. — 18th of September. 
— 6 months. 

To W. Losh, of Benton House, Northamptonshire, esquire, for im- 
provements in iron-rails for rail-roads, and of the chains or pedestals 
in or upon which the rails may be placed or fixed. — 18th of Septem- 
ber. — 2 months. 

To J. Rhodes, junior, of Alverthorp, Wakefield, for improvements in 
machinery for spinning and twisting worsted yarn and other fibrous 
substances. — 18th of September. — 6 months. 



METEOR. 

On Sunday evening last, about half-past eight o'clock, I observed 
a most splendid meteor in the north-east, at an altitude of about 4-5°, 



Intelligence and Miscellaneous Articles* 317 



o 



arid having a diameter of about 20' of a degree. Its course (east- 
ward) was rapid, inclined to the horizon at an angle of about 50°, 
and described in three or four seconds an arch of about 15°, when 
it disappeared quite abruptly. During its appearance the light was 
of a splendour equal to that of the mid-day sun. 

At Newhouses, about a mile north of this place, it appeared at 
the commencement of a size not exceeding that of a shooting-star, 
but increased almost instantaneously to a diameter equal to that of 
the sun. On the point of disappearing it separated into numerous 
scintillant fragments. 

Horton in Ribblesdale, Sept. 10, 1828. J. Nixon. 



AURORA BOREALIS ? 

A remarkable light resembling the aurora borealis was lately ob- 
served at Boreham in Essex, by our correspondent Dr. Forster ; it 
occupied the northern hemisphere, to which so late even as mid- 
night it gave a fine clear orange tint, at times so clear that one might 
have read a large print by it. As it declined, a storm gathered in 
the same quarter, which is rather an unusual circumstance ; and by 
about two o'clock thunder began to be heard. The storm increased 
before three, and became one of the most violent ever remembered 
in the county : an almost uninterrupted succession of flashes, with 
sharp and rolling thunder, continued till past four o'clock, when the 
storm gradually passed off. 

SOLAR SPOTS. 

The two solar spots described under our last Meteorological Re- 
port, p. 236, came on the sun's eastern limb again on the 6th instant, 
but from the interposition of clouds the time could not be ascer- 
tained. The lower spot, which had before divided into four, re- 
turned waning, and without any perceptible umbra : by the 9th 
they had increased to eight very small black specks, and on the 12th 
were evanescent, making the period on the sun's disk from the ap- 
pearance of the original spot, sixty days. The upper one returned 
with additional spots near it, which we shall not notice at present, 
although one of them from its proximity has been found useful to 
a continuance of the observations. On the 9th its umbra was con- 
spicuous, but the nucleus had decreased to a small size. On the 
13th it was again nearest to the sun's centre, and on the 16th it 
had lost the eastern side of its umbra. On the 19th at sunset it was 
on the sun's western limb, having a large facula on the eastern side 
of it (in which it is probable another spot will soon appear), and 
must have gone round on his posterior side between 9 and 10 o'clock 
that evening. As it did not return again, we shall now close our 
remarks on it. Up to the 19th instant it had been on the sun's disk 
91 days, a longer period perhaps than any solar spot on record ; 
during which time it presented a variety of changes in appearance 
and magnitude, varying from 4000 to 14,000 miles in diameter, and 
afforded good opportunities from day to day in fine weather of as- 
certaining satisfactorily the apparent time of each revolution, namely, 

27 days, 



318 Meteorological Observations for August 1828. 

27 days, 7 hours, and a few minutes, which latter it would be diffi- 
cult to determine with any degree of accuracy ; however, the minutes 
cannot at the furthest exceed twenty, which we will allow. From 
this time, 27 days, 7 hours, 20 minutes, it is proper to subtract 1 
day, 21 hours, 40 minutes for the angular distance in time that the 
earth made in the ecliptic during each revolution of the spot ; hence 
the real time of each respective revolution, and also the real time of 
the revolution of the sun on its axis, which is the cause of the ap- 
parent motion of the solar spots, is 25 days, 9 hours, and 40 minutes. 
Our daily observations on other solar spots in the interim, after they 
had made one revolution, corroborate the accuracy of this time. 

If any malign influence on the weather exist from the appearance 
of solar spots, it has been verified in the summers of 1816, 1823, 
and 1828, by the great number which then appeared on the sun's 
disk, and the wet and stormy state of the earth's atmosphere at 
these periods. But to demonstrate this hypothesis of a great man, 
which has recently been alluded to in the provincial newspapers, 
would require great labour and anxiety at the telescope in the day; 
yet we think the task is by no means insurmountable, where time 
is no object to an accurate observer. 



METEOROLOGICAL OBSERVATIONS FOR AUGUST 1828. 
Gosport. — Numerical Results for the Month, 
Barom. Max. 30-29 Aug. 26. Wind S.E.— Min. 29-36 Aug. 6. Wind S.W. 
Range of the index 0-93. 

Mean barometrical pressure for the month 29-860 

Spaces described by the rising and falling of the mercury 4-300 

Greatest variation in 24 hours 0-430. — Number of changes 22. 
Therm. Max. 76° Aug. 24 & 25. Wind W.— Min. 47°Aug. 15. Wind N.E. 
Range 29°.— Mean temp.of exter. air 63°-18. For 31 days with in ft 62*60 
Max. var. in 24 hours 25°-00— Mean temp, of spring water at 8 A.M. 55°-20 

De Luc's Whalebone Hygrometer. 

Greatest humidity of the air in the evening of the 13th 94° 

Greatest dryness of the air in the afternoon of the 15th 45 

Range of the index 49 

Mean at 2 P.M. 59°-5 —Mean at 8 A.M. 6G°*4— Mean at 8 P.M. 71*5 

of three observations each day at 8, 2, and 8 o'clock 65-8 

Evaporation for the month 3-05 inches. 
Rain near ground 2-585 inches. 
Prevailing wind, S.W. 

Summary of the Weather. 
A clear sky, 4£; fine, with various modifications of clouds, 12; an over- 
cast sky without rain, 9; rain, 5£. — Total 31 days. 

Clouds. 

Cirrus. Cirrocumulus. Cirrostratus. Stratus. Cumulus. Cumulostr. Nimbus. 

23 15 30 24 26 21 

Scale of the prevailing Winds. 
N. N.E. E. S.E. S. S.W. W. N.W. Days. 
1 4i 2* 3 1 12 3 4 31 

General 



Meteorological Observations for August 1828. 319 

General Observations. — To the 14th of this month the atmosphere con- 
stantly wore a humid aspect, and more or less rain fell daily (accompanied 
with high winds), which from its frequently interrupting the operations of 
the harvest, excited much alarm among the agriculturists in this and the 
adjoining counties for the fate of the outstanding part of their corn crops. 
The remainder of the period being fine and dry, has certainly proved a 
blessing to the country in general, and enabled the farmers to get in their 
wheat and barley in tolerable condition ; and it is said from undoubted 
authority that the crops will yield at least an average quantity, and in many 
places much more. 

In several of the northern districts, it would appear, from their reports, 
that the thunder-storms had been more frequent, and the rain more copious 
than with us, which beat down and spoiled much of the corn ; but the 
weather having changed favourably, they say that all will be well with 
them, and that they shall have no necessity to advance the prices of their 
corn. On the morning of the 5th instant, thunder-storms with heavy rain 
were experienced both on Portsdown Hill and at Southampton : the storm 
at Portsdown was seen from this place, and the thunder repeatedly heard, 
yet only a few drops of rain fell here. On the 9th, 10th, and 11th, four 
strata of clouds one above another frequently prevailed, with a hard gale 
of wind from the S.W., which literally rooted up several trees in this town 
and neighbourhood, and was much felt at Plymouth. It was succeeded on 
the 13th and 14th by a gale equally as strong from the opposite quarter, 
N.E., which blew back the dense black clouds that had been carried thither 
by the S.W. gale. The latter day was remarkably cold, the mean tempe- 
rature of the external air being only equal to that in the middle of May. 

The atmospheric and meteoric phenomena that have come within our 
observations this month, are three parhelia, two solar halos, forty-four 
meteors ; thunder on three different days ; lightning in the evening of the 
10th; and twelve gales of wind, or days on which they have prevailed ; 
namely, four from the North-east, seven from the South-west, and one from 
the North-west. 



REMARKS. 

London. — August 1. Very fine. 2. Slight rain in morning; showery. 
3. Rainy. 4, 5. Very fine. 6. Heavy rain with thunder in evening. 
7. Cloudy with showers. 8. Very fine. 9. Stormy with showers. 10. Fine. 
1 1. Cloudy, with rain at night. 1 2. Showery. 1 3. Heavy rain. 1 4. Rainy. 
15. Fine. 16. Foggy morning: very fine. 17. Cloudy. 18 — 20. Very 
fine. 21, 22. Showery. 23,24. Very fine. 25. Sultry and warm. 26. Foggy 
morning : very fine. 27— 30. Very fine. 31. Cloudy. 

Boston. — August 1. Cloudy. 2. Rain. 3. Fine : rain, p.m. 4. Fine: 
rain p.m., distant thunder p.m. 5. Fine : heavy rain p.m. 6. Cloudy: rain p.m. 
7. Cloudy. 8. Fine: storm of wind: rain, thunder, and lightning, 5 p.m. 

9. Fine : stormy day, rain p.m. 10. Stormy. 11. Cloudy : storm of wind, 
rain, hail, thunder and lightning, 4 p.m. 1 2. Stormy. 1 3. Fine. 14. Rain. 
15. Cloudy. 16. Fine. 17. Cloudy: rain early in the morning and p.m. 
18 — 20. Fine. 21. Fine: rain a.m. 22. Cloudy: rain a.m. and p.m. 23. Fine. 
24, 25. Cloudy. 26. Misty. 27. Fine : 3 p.m. Therm. 74°. 28. Misty. 
29. Fine. 30, 31. Cloudy. 

Penzance. — August 1. Rain. 2, 3. Showers. 4, 5. Fair. 6. Rain : fair. 
7. Rain: clear. S.Clear: rain at night, stormy. 9. Cloudy: showers. 

10. Clear: showers. 11. Clear: heavy showers. 12, 13. Fair: showers. 
14. Heavy rain: fair. 15. Showers. 16. Rain: misty. 17. Rain: fair. 
18, 19. Clear. 20— 22. Fair. 23. Clear. 24. Fair. 25— 31. Clear. 

Meteor -o- 



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THE 

PHILOSOPHICAL MAGAZINE 

AND 

ANNALS OF PHILOSOPHY. 

[NEW SERIES.] 



NO V EMBER 1828. 



LIV. Answer to an Article by Mr. Henry Meikle, published 
in No. VII. of the Quarterly Journal of Science, By 
J. Ivory, Esq. M.A. F.R.S. $c* 

TN the last Number of the Quarterly Journal of Science, 
* there is an article of some length by Mr. Henry Meikle, 
in which he animadverts in a style which is hardly called for, 
on the analytical theory of sound, and on the variation of 
temperature which air undergoes when it changes its bulk. 
In his strictures on the first of these subjects he does little 
more than enlarge on the observations which Professor Leslie 
has more briefly made relative to the same matter in the arti- 
cle Acoustics, in the Supplement to the Encyclopcedi a Britannica. 
Whatever purpose such discussions may serve, one is at a loss 
to find out how they can benefit science. Great fault is found ; 
no remedy is proposed ; the subject is ultimately left just where 
the author found it ; and the whole ends in a vain display of 
learning and fine writing. Whoever will attend to Mr. Mei- 
kle's remarks will soon be convinced that any attempt to an- 
swer them is not a very likely way to elucidate, or to improve, 
the theory he attacks. Besides, this theory has been long 
known ; 1 have only made use of the most simple case of it 
for a particular purpose ; and therefore I do not think myself 
indispensably called upon to defend it against such arguments 
as are contained in the article under consideration. Leaving, 
then, the analytical theory of the propagation of sound to 
stand on its own merits, 1 must, however, express my regret 
that Mr. Meikle has made so little progress towards that 
thorough reform which, he thinks, is so necessary, 

* Communicated by the Author. 
New Series. Vol. 4. No. 23. Nov. 1828, 2 T I pro- 



322 Mr. Ivory's Answer to an Article by Mr. Henry Meikle 

I proceed next to Mr. Meikle's strictures on the explana- 
tion, I have given, of the variation of temperature when air 
changes its bulk. I have not seen any of the articles he cites in 
the Edin. Phil. Journ. What I have written on this subject is 
no more than an easy deduction from the usual theory of the 
thermometer ; and the best way to enable the reader to judge 
of the justness of Mr. Meikle's animadversions, is briefly to 
explain the principles I proceed upon, disengaging them, as 
far as perspicuity will permit, from all purely mathematical 
calculations. 

In an air- thermometer, or, which is the same thing, in a 
mass of air which changes its bulk by the application of heat, 
the pressure being constant, I take it for granted that the ca- 
pacity of the air for heat, within certain limits, remains inva- 
riable; that is, I suppose that equal quantities of absolute 
heat, produce equal variations of volume and temperature. It 
will be admitted that this postulate is true, so long as two 
thermometers, one of air and the other of mercury, both ex- 
posed to the same flow of heat, continue to indicate the same 
temperatures. To speak more particularly, but without aim- 
ing at great precision, the capacity of air for heat may be sup- 
posed constant between —40° and +300° on the centigrade 
scale, comprising a range of temperature between 300° and 
400°. The reasoning which follows is entirely founded on 
this experimental fact, and it must be considered as applying 
only within the limits mentioned. 

Suppose that the given mass of air has undergone a certain 
variation of bulk ; and let us put h for the whole quantity of 
heat which has produced this effect ; and t, for the change of 
temperature in passing from the one volume to the other ; then 

we shall have — = k 9 k standing for some number not yet 

known, which however is invariably the same so long as the 
temperature t is contained within the assigned limits. All 
this is manifest from what is said above; for the equation 
merely expresses that the absolute heat which causes any 
change of volume is proportional to the variation of tempera- 
ture, according to the postulate laid down, and as must be the 
case if the thermometer be an exact measurer of heat. Now 
h, whether it is heat added to, or abstracted from, the mass 
of air, is always greater than t, the rise or depression of tem- 
perature. For when heat is added, the volume of the air is 
enlarged, and some heat is absorbed and disappears without 
acting on the thermometer ; on the other hand when heat is abs- 
tracted, the volume is diminished, and some heat is evolved 

which 



in the Quarterly Journal of Science, 323 

which is instantaneously dissipated and produces no effect on 
the fall of temperature. We may therefore put h = i + r ; 
and, on account of the foregoing equation, we shall have, 

f = *-l. (a) 

The new symbol i stands for the difference between the absolute 
heat, and the heat of temperature, answering to any change of 
the bulk ; or it is the heat which enters into the air when its 
volume increases, and is again extricated when the volume 
decreases, without affecting the thermometer in either case. 
I shall call latent heat, that portion of the absolute heat which 
in ordinary circumstances is not indicated by the thermome- 
ter, when a mass of air under a constant pressure changes its 
bulk. This term was introduced by Dr. Black ; but it has 
been objected to and proscribed by some chemists, who ex- 
press the same thing by a phraseology certainly not more per- 
spicuous. There can be no impropriety nor inconvenience in 
using the term, since it is no more than the unambiguous ex- 
pression of a fact, the existence of which is certain. It re- 
mains now to discover the value of the number k; for when 
this is done, the equation (a), taken always within the assigned 
limits, contains the whole of the doctrine under consideration. 

In order to find the number k 9 or k — l, we must have re- 
course to an experiment contrived by MM. Clement and Des- 
brmes. These celebrated chemists have invented a very in- 
genious process by which we can ascertain the proportion of 
the latent heat to the heat of temperature, that is, the value of 

— , when a given mass of air under a constant pressure suf- 
fers a small variation of bulk. Taking an average of many 
experiments, it has been found that — and — , that is, /rand 

k— 1, are nearly equal to ~y~ and -| . Now, making &— 1 = §, 
the equation (a) will coincide with the conclusion which I have 
stated at p. 94< of this Journal for February 1827, and which 
enables us to compute the latent heat for a given variation of 
bulk. MM. Gay-Lussac and Welter repeated the experi- 
ment alluded to on air under a great variety of pressures, and 
in a range of temperature reaching from —20° to +40° on 
the centigrade scale ; and the resulting proportion of the latent 
heat to the heat of temperature came out in every instance very 
nearly the same. By this means, not only are the numbers k 
and & — 1 ascertained to a considerable degree of precision, 
but it is likewise demonstrated that, within certain limits, they 
are independent of the state of the air. Now this is a practical 
proof in favour of the theory we have been explaining ; since, 
2 T2 as 



324? Mr. Ivory's Answer to an Article by Mr. Henry Meikle 

as far as experiments have been extended, the ratios — and 

— are found to remain constant, as the theory requires. 

But in applying the foregoing doctrine to the velocity of 
sound, I made use of algebraic formulas, which are things held in 
abhorrence by a certain class, although it appears that others 
know very well how to turn them to their own purposes. 
Taking a mass of air at a given temperature, suppose zero of 
the centigrade scale, let a denote the dilatation under a con- 
stant pressure for 1° of temperature, and /3 the dilatation re- 
quisite for the absorption of 1° of latent heat; then it is ob- 
vious that shall we have, 

I now take one of the formulas marked (C) at p. 252 of this 
Journal for April 1827, viz. 

e l +«j 

whence I get, i = — • (1 -f a 0) (- l\ 

It will perhaps contribute in some degree to perspicuity, if, 
instead of the proportion of the densities — , we substitute the 

inverse proportion of the volumes, viz. -—7- ; then 

*•«- s-(i+««)(-f-i). 

The formula will be still more simplified if we make the initial 
temperature equal to zero, in which case V will be the vo- 
lume of the air at the beginning of the thermometrical scale ; 
then ! v . 

And, if t be the variation of temperature, we obtain, by the 
theory of the thermometer, 

--K-v-r-0- 

These formulas show clearly the relation that subsists be- 
tween the temperature and the latent heat, and in what man- 
ner both these quantities are derived from the volume. Both 
the expressions are significant, and represent what actually 
takes place in nature, so long as the postulate on which they 
are founded holds good ; or so long as the capacity of the air 
for heat remains constant, and the absolute heat which changes 
the bulk of a mass of air is proportional to the variation of 
temperature. Beyond this limit on either side, the formulas 
become insignificant; they are mere abstract expressions 

which 



in the Quarterly Journal of Science. 325 

which denote nothing that is true in nature. It is therefore 
absurd to contend from the numerical results obtained in 
some extreme cases, that the formulas are consonant to fact 
in no case whatever ; I say, the formulas, for the argument ap- 
plies equally to both. Suppose that the original volume is 
reduced to a very small space, or to a point ; then, according 
to the centigrade scale, 

t = -266°-7, I = -100°. 
Now these numbers are either both true, or neither of them 
is so ; and the latter may be affirmed, since it is very impro- 
bable, that a law, which has been verified only for a small part 
of the thermometrical scale, will continue to hold good without 
limit ; it is even certain that it will not. Next let us suppose 
that the volume of air has decreased to half its original quan- 
tity ; then, T r= — 133°, i = - 50°. 
There is good reason to think that these numbers are not far 
from the truth ; but it would be rash to affirm that they agree 
exactly with the phenomenon ; for there is no proof, at least 
I am not aware of any, that a mass of air at the temperature 
zero, being cooled down to half its bulk, will still preserve the 
same capacity for heat. If we suppose a greater diminution 
of volume than one half, we are entirely ignorant of the man- 
ner in which the temperature and the volume vary in regard 
to the absolute heat ; and, as the principle of the investigation 
now ceases to be exact, the conclusions obtained, whether ex- 
pressed in algebraic language or otherwise, must no longer 
be applied. 

All Mr. Meikle's objections to my doctrine are derived from 
the extreme cases just mentioned. His arguments have no 
force ; since I have always confined my speculations to the 
limits within which the thermometer can be reckoned an ex- 
act measurer of heat. He finds many inconsistencies, and he 
descants on this topic with so much politeness, that he seems 
seriously to think, his remarks have some foundation. If such 
be the case, it will be allowed that the same ability does not 
attend the same person on all subjects and on all occasions ; 
for we can here recognise very little of that acuteness and sa- 
gacity from which we expect the thorough reform. 

M. Poisson has treated this subject in an able memoir in 
the Conn, des Temps 1826. His equations agree with the 
doctrine here delivered as far as the formula (7), p. 264, which 
is derived from an integral to which I have objected. On the 

preceding page he arrives at this equation, — as k — 1, k 

standing for the same value as in this article, and co and n 
being the variations of latent heat and temperature arising 

from 



326 Mr. Addison's Remarks on the Itifluence of Terrestrial 

from a small condensation y. The equation may therefore 

be thus written, -- = &— 1 ; and as it is true of any number 

of continuous variations of density or volume, the pressure 
being constant, it agrees with the equation (a) investigated 

above. Observing also that y = — , and k — 1 = ~, his 

two equations (5) and (6) will become, 

adr d(> 

\ + u6 ~" ~' 
fidi _ d{ 

T+7T - "P 
being the actual temperature of the air. In the first of these 
equations, dy is derived from dr; and in the second, dg de- 
termines di. The two equations are therefore intimately con- 
nected, and no just conclusion can be deduced from the se- 
cond, if the first be overlooked. Now M. Poisson has inte- 
grated the second equation apart, and as if it were in no re- 
spect modified by the first. This is the ground of my objec- 
tion. In reality the integral he obtains satisfies the second 
equation, but it does not satisfy the first, as it ought to do 
according to his own calculations. If we reason fairly, and 
fulfil all the relations of the differential quantities, we shall be 
necessarily led, even when we follow M. Poisson's train of in- 
vestigation, to the same theory explained in the present and 
in former articles of this Journal*. 
Oct. 13, 1828. J. Ivory. 

LV. Remarks on the Influence of Terrestrial Radiation in 
determining the Site of Malaria. By Wm. Addison. 

[Concluded from p. 278.] 

ONE of the chief arguments in favour of the important in- 
fluence exerted by terrestrial radiation in the production 
of that state of the atmosphere favourable to the attacks of 
disease, and known by the name of malaria, is drawn from 
the fact that in almost, nay I might say every case, where the 
violence of the symptoms induced by it will permit us to ob- 
serve the first impressions which it causes, we find that its 
baneful influence is exerted during the night-season, while in 
the day-time it is comparatively, if not quite, inert. It would 
be needless to reiterate here the numerous proofs of this, dis- 
tributed among the writings of those many accurate observers 
who have been at the pains of noticing the habitudes of ma- 

• See Phil. Mag. and Annals for October 1827, pp. 245, 246, 247. 

laria. 



Radiation in determining the Site of Malaria. 327 

laria. I shall content myself, therefore, with quoting only 
Dr. Ferguson, who observes in his History of the Marsh 
Poison, " that the rarifying heat of the sun dispels the miasms 
which create fevers and violent diseases, and that it is only 
during the cooler temperature of the night, that they acquire 
body, concentration, and power." 

Now surely any miasmatous effluvia liberated from ex- 
posed vegeto-animal or other matters by the rays of the sun, 
must exist in the atmosphere as much if not more during the 
day-season than in the night; for it is more than probable that 
nothing is given up by the ground after sun-set. How is it then, 
we may ask, that the great potency of malaria at night, and 
its comparative harmlessness during the day,have so constantly 
forced themselves upon our notice? Is it not because the air 
during the former period is cooled by radiation and rendered 
incapable of retaining those matters which the warmer air of 
the day-time held in perfect solution? A still atmosphere 
containing miasmatous matters, therefore, becomes dangerous 
to health in proportion as it reaches, by a gradual reduction 
of temperature, such as ensues from radiation, its dew point : 
for during the period when its temperature is elevated above 
this point, the malarious matter is without any, or of but little 
injurious agency ; while the nearer it approaches the point at 
which moisture will be liberated from it, the more those ex- 
traneous matters it may contain become developed, as is fully 
shown by the much greater potency of odours at that period, 
of which numerous instances might here be mentioned; but 
it will be sufficient to recall what every one must have ob- 
served during the summer months: after a hot day, if the air 
at night remains still, or is favourable to the process of radia- 
tion, it is truly astonishing how far odours will diffuse them- 
selves, and how powerful they generally are : a few hours after 
sun-set, on evenings favourable to the deposition of dew, many 
effluvia become very perceptible, and are potent and concen- 
trated in proportion to the stillness of the air and its approach to 
the dew point. Winds, although they very often cause consider- 
able reductions of temperature, are not so prejudicial, or so fre- 
quently productive of ill effects upon the human body, as those 
abstractions of caloric resulting from radiation ; and for this 
reason, — because in the former instance the morbific particles 
are dispersed, and so diluted by the aerial currents as to be 
rendered incapable of exercising any injurious influence upon 
the body, or only upon such as are rendered extremely sen- 
sible to the exciting causes of disease ; whereas in the latter 
instance they become often greatly accumulated, and so highly 
prejudicial, that few escape. 

In 



328 Mr. Addison's Remarks on the Influence of Terrestrial 

In this country the pernicious nature of the morning and 
evening mists formed over low grounds has been observed, 
and in hotter climates I need scarcely say that their influence 
in generating fever is as notorious as any of the best established 
facts on this subject; and the progress of the sun upwards 
being a remedy for the morning mists, and the day altogether 
for those of the night, seems to confirm the opinion, that a 
watery and moist atmosphere is the active conductor or repo- 
sitory of malaria ; and that when the former is dissipated, the 
latter is checked in its progress ; when the one is entirely di- 
spersed, the other may be destroyed : so that the matter of 
malaria seems to be defined as to its place and extent by va- 
pour and mist*. 

That the diseases arising from miasmata in the air do some- 
times cease in a definite and sudden line, and terminate also 
at particular altitudes, has often been observed and recorded ; 
and these remarkable instances cannot be satisfactorily ex- 
plained upon any other supposition than that afforded by the 
radiation of caloric. To explain their cessation in the former 
instance, we may remark, that that depression of temperature 
which ensues at night over a good radiating surface, may be 
sufficient to render active the miasms existing in the air ; while 
over others, less powerful in the dissipation of caloric, the de- 
pression of temperature may not be sufficient; and it is probable 
that in many cases an atmosphere rendered prejudicial by the 
one, is again made innoxious by passing over the other. With 
respect to altitude, I have before shown that slight elevations 
are frequently a protection against the heavy miasmatous air 
which subsides to the lowest situations. 

But to place this important subject in the clearest possible 
light, let me endeavour (by an appeal to some well-known 
chemical facts) to set forth the nature of the connection ex- 
isting between free caloric and the matter of malaria. Let us 
suppose that the former exerts over the latter an influence ana- 
logous to that exercised by an acid over an alkali (neutralizing 
its qualities and destroying its effects), and we shall immedi- 
ately perceive that the mere presence of malarious matters in 
the air may not be sufficient to excite in the human body 
a state of disorder or disease: carry the reasoning a little 
further, and then we can fully understand the way in which 
radiation proves injurious. Are we not warranted in conclu- 
ding, from those facts which observation and experience have 
discovered to us, that similar phaenomena are exhibited in the 
relations subsisting between the matter of heat and miasmatous 

* Vide Macculloch's Essay, pp. 259 and 274. 

effluvia 



Radiation in determining the Site of Malaria. 329 

effluvia, as we witness among the various combinations of the 
chemical world ? Withdraw one of the elements of a binary 
compound, and the other becomes immediately apparent, and 
is developed with all those potent qualities which had been 
destroyed or neutralized whilst in union. So miasmatous mat- 
ters are inert while fixed to the ground, from which they can 
arise only in conjunction with caloric ; and as long as they 
continue together no ill effects ensue : but diminish the tem- 
perature, or, in other words, take away the caloric, and the 
injurious qualities of the miasms immediately become appa- 
rent. It may be objected, that if the injurious agency of mi- 
asmata in the air results from the mere abstraction of heat, no 
reduction of temperature could ensue without the production 
of malaria. — But this is not true ; for we may justly suppose 
that in a great majority of cases there is not sufricient noxious 
matter on the ground to saturate — if I may be allowed the 
term — the caloric existing in the air, and therefore that in these 
instances great reductions of temperature may take place with- 
out any appearance of malaria, in the same manner as (to carry 
on the analogy drawn from chemical combinations) we can 
detach a portion of the acid from a supersaturated salt, with- 
out developing the existence or qualities of the alkali. On the 
other hand, the miasmatous source may sometimes afford a 
supply amply sufricient to satisfy even a very high temperature; 
and then any trifling escape of caloric will be accompanied 
with an injurious precipitation : and if the cooling process con- 
tinues, a highly noxious malaria will result. 

It has been observed, that very often the diseases arising 
from malaria ensue upon the temperature of a place reaching 
a certain point ; that they increase in frequency and violence as 
the heat increases, but diminish as the mean temperature falls. 
These facts are not at all irreconcileable with the phenomena 
of radiation; for in these cases we may justly suppose, that at 
the higher temperatures malarious matter is liberated from the 
soil, the quantity of which is greater in proportion to the ther- 
mometric rise, while the lower temperatures are not sufficient 
to liberate any quantity of the noxious effluvium and diffuse it 
through the air : in the former case the radiation of caloric 
will be attended with disease, in the latter it will not. 

I might here relate many facts tending to show the inti- 
mate connection w r hich subsists between caloric and miasma- 
tous effluvia, but I conceive that what has been here stated 
will be ample to establish this point, as well as the fact that the 
latter become virulent in proportion to the abstraction of the 
former by the process of radiation. 

In conclusion, I shall briefly point out the importance of 
New Scries. Vol. 4% No. 23. Nov. 1828. 2 U the 



3 SO On the Dependence of Malaria on Terrestrial Radiation. 

the foregoing observations* if they shall be found correct, to- 
wards the attainment of that desirable end, the protection of 
mankind against the injurious impregnations of the air. 

As regards the prevention of the rise of miasms from the 
ground, I fear we have too little controul over the powerful 
agency of the rays of the sun to adopt successfully any plan 
with reference to this head. The solar influence is too great and 
too general to enable us to obstruct the emanation of various 
effluvia from the soil : nevertheless, much may be done by re- 
moving as far as possible from the surface of the ground any 
thing likely to afford them ; and although our endeavours on 
this point must be very inefficient, they may be more success- 
ful and beneficial if directed to obviate those conditions which, 
as we have seen, have such a considerable effect in rendering 
active the noxious properties of malaria; viz. 1st, by prevent- 
ing the dissipation of caloric through a still atmosphere; 
and, 2ndly, by promoting those aerial currents which tend so 
much to dilute and carry off any deposition which may ensue 
from that process. 

In order to accomplish the former of these indications, we 
must use every means in our power to diminish the radiation 
of heat from the ground after sun set, or to remove as far as 
possible from the circle of its operation, by attaining during 
the night-season some moderate elevation, interspersed here 
and there with lofty trees, and hedges or inclosures, and placed 
to windward of the more rapidly radiating surfaces which may 
be near : for although we speak of a calm and still atmosphere 
as being highly favourable to the development of malaria, still 
it must be understood that in almost every instance there are 
gentle, although perhaps imperceptible currents in the air, fully 
sufficient to waft to a considerable distance the miasms libe- 
rated by the dissipation of caloric ; and any increase of tem- 
perature which such currents may acquire in their passage over 
less perfect radiators, will not always be enough to disarm them 
of their injurious influence. In situations therefore more 
particularly, where we are likely to be subjected to miasma- 
tous products, and where the air at night is generally still, or 
where the gentle breezes are found to sweep over tracts fa- 
vourable to radiation, it behoves us to endeavour, — by exciting 
artificially aerial currents, and by raising or keeping up the 
temperature of the air of the place where we may be by cir- 
cumstances constrained to remain, — to prevent the deposition 
and development of malaria. This may be accomplished by 
lighting large fires to windward of the place of our nightly so- 
journ. — This is not a new idea: fires have already been observed 
to be beneficial in warding off the nocent power of malaria, 

though 



Mr. Graham's Account of the Formation of Alcoates. 331 

though the principle upon which they act has not been pro- 
perly understood, and consequently they have never been 
employed to the best advantage for this purpose. Dr. Mac- 
culloch relates a very important case, where a superintendant 
engaged in directing the cutting of wood in Africa, erected 
thirty earthen furnaces on the spot where his men were em- 
ployed, lighting them every day. Before this, he had always 
from forty to forty-eight of his workmen sick ; when in a 
short time they were reduced to twelve, then to four, and 
finally to one. Napoleon adopted the same expedient very 
largely, and with success, when his armies were occupied in 
the very worst district of Italy*. Knowing the principle of 
their operation, I should recommend them to be lighted at 
sun-set, and to be allowed to burn until sun-rise, having a re- 
gard to their position as pointed out in the foregoing remarks. 
Where Jarge numbers of human beings are congregated to- 
gether, as in armies, camps, &c, and where their situation at 
night is too often determined by other circumstances than sa- 
lubrity, the value of, these observations, with the knowledge of 
the principles which should direct their application, cannot but 
be very apparent. 

It will be easily seen, from what has already been said, that 
fires as defences against malaria will be much more necessary 
during the nocturnal period than at any other ; and even at 
this season, when the wind is blowing strongly and the night is 
overcast, they will not be so much required as when the air is 
clear and still. — It is not my intention to speak here of those 
various extraneous circumstances which render the body more 
susceptible of injurious influences at night than during the 
day, — such as bodily and mental exhaustion, sleep and dimi- 
nished temperature ; nevertheless they are well worthy of our 
serious regard, as cooperating powerfully with noxious mias- 
mata in producing a state of disease. 

Malvern, July 1, 1828. WlLLIAM ADDISON. 



I^VI. An Account of the Formatio?i of Alcoates, Definite Com- 
pounds of Salts and Alcohol analogous to the Hydrates. By 
Thomas Graham, Esq. M.A. F.R.S.E. 

[Concluded from page 272.] 
II. Alcoate of Nitrate of Magnesia. 
FT is difficult to expel the whole of the w r ater with which ni- 
■*- trate of magnesia is combined, without driving off a por- 
tion of the acid, and decomposing the salt. For this salt may 
* Maccul loch's Essav, p. 286. 

2 U 2 be 



332 Mr. Graham's Account of the Formation of Alcoates. 

be wholly reduced [to magnesia] in a glass-tube by the heat of a 
spirit-lamp, and yet a sand-bath heat of 600° or 700° is not suf- 
ficient to drive off all its water of crystallization. But a partial 
decomposition of this salt is of no great consequence, as alcohol 
dissolves the undecomposed portion of the salt, while the mag- 
nesia resulting from the decomposition precipitates, and may 
be separated by decanting the solution, or by filtering. 

Four parts alcohol at 60° dissolve one part nitrate of mag- 
nesia, and boiling alcohol dissolves more than half its weight 
of this salt. From the great difference between the solubility 
of this salt at high and low temperatures, the alcoate is ob- 
tained with facility. A hot solution, containing a greater pro- 
portion of nitrate than one part to three parts alcohol, became, 
upon cooling, an irregular dry mass, which could be indented 
by the point of a glass-rod, but was much harder than the al- 
coate of chloride of calcium. In solutions considerably weaker 
crystals were deposited on cooling, which sometimes resembled 
the crystals of the former alcoate, but were much smaller, and 
less distinct ; but more frequently, the crystals were exceed- 
ingly minute, and detached, without any regular form which 
could be discerned. But the great mass of crystalline matter 
precipitated in scales of a pearly lustre and whiteness, but ap- 
parently made up of the small crystals. 

Dried by pressure, in blotting paper, this alcoate much re- 
sembled the alcoate of chloride of calcium in external charac- 
ters. It sank in water, but floated on the surface of a saline 
solution of the specific gravity 1*1. Heated, it melted readily ; 
boiled, and much alcohol was given off. When boiled vio- 
lently, red fumes rise with the alcohol-vapour ; but when dried 
slowly, no loss of acid takes place. 

Upon cautiously heating 13*4 grains alcoate of nitrate of 
magnesia to dryness, there remained 3*56 grains nitrate of 
magnesia. This gives 9*84 alcohol to 3*56 nitrate of magnesia. 
But the atomic weight of anhydrous nitrate of magnesia is 
9*25. Now, 3*56 : 9-84 : : 9*25 : 25*57. 

In another case, 16 grains alcoate were reduced to 4*2 grains. 
This gives 1 1*8 grains alcohol to 4*2 grains nitrate of magnesia. 
4-2 : 11-8:: 9*25: 25-99. 

On the supposition that this alcoate consists of one atom 
nitrate of magnesia united with nine atoms alcohol, the alcohol 
should amount to 25*875, a number intermediate between the 
two results. This alcoate will be thus represented : 

One atom nitrate of magnesia 9*25 

Nine atoms alcohol 25*875 

35*125 

III. Alcoate 



Mr. Graham's Account of the Formation ofAlcoates. 333 

III. Alcoate of the Nitrate of Lime. 

Nitrate of lime may be obtained anhydrous with much 
greater facility than nitrate of magnesia, as, after being dried 
on the sand-bath, it may be heated in a glass-capsule by the 
spirit-lamp without decomposition, although it partially fuses. 
Boiling alcohol saturated with this salt formed a solution, 
which became very viscid on cooling, and remained without 
crystallizing for a whole day. But during a frost} 7 night it 
was resolved into an amorphous solid, slightly moist, but with- 
out any appearance of crystallization. This substance was 
carefully dried in the usual way. 

14*8 grains were reduced by heat to 8*8 grains. This gives 
6 grains alcohol to 8*8 grains nitrate of lime. The atomic 
weight of anhydrous nitrate of lime is 10*25. Now, 

8-8:6:: 10*25: 6*98. 

In another case, 15*6 grains were reduced to 9*2, which 
gives 6*4? alcohol to 9*2 nitrate of lime. But, 

9-2:6-4:: 10-25: 7-13. 

This approaches 7*1875, or two and a half equivalent propor- 
tions of alcohol. The composition of the alcoate of nitrate of 
lime would be represented on this view, by 

Two atoms nitrate of lime 20*5 

Five atoms alcohol 14-375 



34-875 
In another strong alcoholic solution of nitrate of lime, a few 
irregular crystals were deposited ; but the quantity was not 
sufficient to admit of examination, although they proved that 
this alcoate is capable of crystallizing. 

IV. Alcoate of Protochloride of Manganese. 

The protochloride of manganese, dried in a glass-tube, at a 
red heat, was light, friable, and of a reddish colour. Alcohol 
dissolved a very large quantity of it. When the solution was 
made at a high temperature, the alcoate crystallized readily 
upon cooling in plates with ragged edges. 14*6 grains of this 
alcoate, carefully dried by pressure in blotting paper, were re- 
duced by heat to 7 grains. The alcoate, therefore, consisted 
of 7 grains protochloride of manganese, and 7*6 grains alcohol. 
The atomic weight of protochloride of manganese is 8. Now, 

7 : 7*6 : : 8 : 8'686. 
This slightly exceeds three atoms alcohol = 8*625, but the 
approximation to the theoretical number is as close as could 

be 



334- Mr. Graham's Account of the Formation of Alcoates. 

be expected. The composition of this alcoate may therefore 

be expressed by 

One atom protochloride of manganese 8* 
Three atoms alcohol 8*625 



16-625. 
V. Alcoate of Chloride of Zinc, 

Alcohol dissolves chloride of zinc with great facility, and 
the solution when filtered is of a light amber colour. This 
solution may be concentrated to a very great extent without 
injury, and becomes so viscid when cold, that it may be in- 
verted without flowing perceptibly. It is not till so concen- 
trated that it begins to deposit crystals, which are small and 
independent, but apparently of no regular shape. A viscid 
solution, in which crystals formed, was found to be composed 
of 20 parts chloride of zinc, and 7 parts alcohol. The small 
proportion of alcohol is astonishing; yet no more alcohol was 
given out when the chloride was heated nearly to redness, and 
began to volatilize; nor did a portion of the chloride thus 
heated take fire when exposed directly to the flame of a 
candle. 

The crystalline matter was dried with difficulty by pressure 
in blotting paper. When dry, it possessed the usual waxy 
softness of the alcoates, and was of a yellowish colour. Heated, 
it entered into a state of semifusion, and gave off its alcohol. 
Nine grains alcoate were reduced by the application of suffi- 
cient heat to 7*65 grains. Hence the alcoate consisted of 7*65 
chloride of zinc, and 1*35 alcohol. But the atomic weight of 
chloride of zinc is 8*75. 

7-65: 1-35:: 8*75: 1*54.4.. 

1*54.4? slightly exceeds 1*4375, or half an atomic proportion 
of alcohol. It is probable that the excess was owing to the 
difficulty of freeing the alcoate completely from the viscid so- 
lution. According to this view, the alcoate of zinc consists of 

Two atoms chloride of zinc ... 17*5 

One atom alcohol 2*875 



20*375 
Besides these alcoates, similar compounds of chloride of 
magnesium and of protochloride of iron and alcohol were 
formed, although in quantities too minute to enable me to as- 
certain their proportions. Alcohol is retained with great force 
by chloride of iron, and is partially decomposed when heated, 
as is the case with many metallic chlorides. 

As I had it only in my power to present the fixed alkalies 
to absolute alcohol in the state of hydrates, no alcoate ap- 
peared 



Mr. Graham's Account of the Formatiori ofAkoaies. 33$ 

peared to be formed. The same was the case with the vege-< 
table acids soluble in alcohol. 

It is probable that many more alcoates of salts may be 
formed, particularly of the metallic chlorides. The great ob- 
stacle to their formation is the difficulty, and frequently the 
impossibility, of rendering the salts perfectly anhydrous, be- 
fore their solution in alcohol is attempted. 



I am not aware of any other compounds in the solid form 
of the same class as the hydrates and alcoates. But there is 
an oxide, classed by Dr. Thomson in his System of Chemistry, 
with water and other neutral and unsalifiable oxides, the ha- 
bitudes of which with certain salts are exceedingly remarkable, 
and have been looked upon as anomalous, but on which the 
established properties of hydrates and alcoates appear to me 
to throw some light. I refer to the deutoxide Of azote or ni- 
trous gas. 100 volumes pure water are capable of absorbing 
only 5 volumes of this gas, according to the experiments of 
Dr. Henry. But Dr. Priestley and Sir H. Davy ascertained 
that certain metallic salts, particularly the protosalts of iron, 
are capable of absorbing this gas in large quantities ; and again 
emit the greater part of it unaltered, on being heated. That 
the absorption of deutoxide of azote by these salts, is not de- 
pendent upon the oxygen of their bases, or the water which 
they contain, I have proved in two ways, in the case of pro- 
tomuriate of iron. By heating this salt to redness in a glass- 
tube, it is reduced to the state of protochloride of iron. Now, 
I find that this chloride in the dry state absorbs deutoxide of 
azote, although in a comparatively small proportion. And the 
alcoholic solution of the chloride, where neither oxygen nor 
water interferes, appears to exceed the aqueous solution of 
the protomuriate in its capacity for deutoxide of azote. 

Deutoxide of azote, formed by the action of dilute nitric 
acid on copper, was conducted into a globular receiver sur- 
rounded by cold water, and thence through a glass-tube of 
two feet in length, filled with small fragments o£ chloride of 
calcium. Thus dried, the deutoxide of azote was passed slowly 
over carefully prepared protochloride of iron in the state of 
powder, and contained in a glass-tube of small diameter. The 
protochloride immediately became darker in colour ; and upon 
being withdrawn, after exposure to the current of gas for some 
time, was found to retain the smell of nitrous gas, and to have 
increased in weight. In one case, 30 grains chloride had in- 
creased to 31*1 grains; and in another case, 25 grains chloride 

to 



336 Mr. Graham's Account of the Formation of Alcoates. 

to 25*5 grains. On being gently heated, the deutoxide of 
azote was evolved, and the chloride restored to its former co- 
lour. 

The solution of protochloride of iron in absolute alcohol, 
absorbed a much greater quantity of deutoxide of azote, and 
became nearly black. A solution saturated with gas began 
to boil at 100°, evolving gas in great abundance, which, being 
collected in the pneumatic trough, proved to be pure deutoxide 
of azote. The greater part of the gas was expelled before the 
alcohol rose to its boiling point, and after the solution was in 
the state of ebullition for a few seconds gas ceased to rise, and 
the alcoholic solution recovered its original colour, which was 
generally a chocolate-brown, from the presence of a little bi- 
chloride of iron. The quantity of gas evolved from a solution 
of one part protochloride of iron in five parts absolute alcohol, 
amounted to 23 times the volume of the alcohol. 

I think it probable that the absorption of deutoxide of azote 
by protochloride of iron, is analogous to the absorption of al- 
coholic and aqueous vapours by the same body. For I find 
that protochloride of iron absorbs alcohol-vapour as well as 
the vapour of water. The absorption of deutoxide of azote 
may depend upon a tendency of chloride of iron to deliquesce 
in like manner, in an atmosphere of that neutral oxide. At 
a very low temperature, which it is perhaps out of our power 
to reach, protochloride of iron would probably absorb this gas 
in sufficient quantity to exhibit the appearance of delique- 
scence, "and might form with it a neutral compound similar 
to its alcoate or hydrate. 

A reason can also be given for the superiority of the aqueous 
and alcoholic solutions of this chloride over the dry chloride 
itself, in absorbing deutoxide of azote. We formerly saw that 
the alcohol of the alcoate of chloride of calcium was completely 
expelled by a heat of 250°, when no water was present, but 
that, when a considerable quantity of water was present, al- 
cohol was retained by that chloride at the temperature of 400° 
or 500°. Now, chloride of iron might be enabled to retain 
deutoxide of azote more powerfully, by the assistance of al- 
cohol or water, in the same manner. But the retaining power 
we have formerly found in a similar case to be an index of the 
absorbing power. Hence solutions of protochloride of iron 
might absorb deutoxide of azote more powerfully than the 
chloride itself. 



LVII. On 



[ 337 ] 

LVII. On the Luminous Zone observed in the Heavens on the 
29th of September last. By Capt. H. Kater, V.P.R.S. 

To Mr. Taylor. 
Sir, 
THHE substance of the following communication was in- 
* serted in the Times newspaper of the 4th of October ; but 
as it seems desirable that phaenomena of this kind should be 
permanently recorded, I shall feel obliged by your giving it a 
place in the Philosophical Magazine. 

On the 29th of September last, Professor Moll and myself, 
being at Chesfield Lodge near Stevenage, observed at 8 h 35 m 
mean time, a zone or luminous belt extending itself in the 
heavens from the eastern to the western horizon. The light 
of the zone was white, uniform or nearly so, and surpassing 
much in intensity that of the milky-way. Its breadth (nearly 
equal throughout) was about three-fourths of the distance 
from /3 to y Aquilae, or 3° 45'. The edges of the belt appeared 
perfectly well defined and equally luminous with the middle, 
and its transparency was such that the stars were distinctly 
seen through it. 

The observations made at the moment were, that the belt 
covered the Pleiades, and appeared to be equally distant from 
a Arietis and y Andromedae. It passed between a Aquilae 
and a Lyrae, at the distance from a Aquilae of one-third or 
two- fifths of the interval between these stars. Professor Moll 
observed that its edges were upon p and y Ophiuchi. Lower 
down, near the western horizon, this luminou szone suffered 
a very remarkable inflexion towards the north, and soon 
after was lost in the clouds at a little distance above the hori- 
zon. On tracing the course of this phaenomenon upon a ce- 
lestial globe, its path appears to have been nearly that of a 
great circle, meeting the horizon about the E.N.E. and W. 
by S. points. The altitude of the centre of the most elevated 
part appears to have been about 72°, so that it must have 
been nearly in the plane of the dipping-needle, and nearly at 
right angles to the magnetic meridian. 

At 8 h 42 m mean time, the belt began to fade slowly from 
the east towards the west, and at 9 h 22 m no trace of it was 
perceptible. Its light during the whole time appeared per- 
fectly steady and without any coruscations. 

There was much wind from the S.E. The stars were un- 
usually bright. The height of the barometer was 29*12 inches, 
and the thermometer 59°. 

It may not be uninteresting to add, that a gentleman re- 
Nexv Series. Vol. 4. No. 23. Nov. 1828. 2 X marked 



338 Expression for the Vibration of a simple Pendulum, 

marked that the setting sun had a very unusual appearance, 
being; as he described it, of a pale dirty yellow : and a letter 
which I have received from Cromer in Norfolk, mentions on 
that evening " a very beautiful setting sun, quite out of the 
common way ;" but it is not stated in what its peculiarity con- 
sisted. 

The latitude of Che'sfield Lodge is 51° 56' 15", and its 
longitude about 43 seconds in time west from Greenwich. 

I am, Sir, your obedient servant, 
Chesfield Lodge, Oct. 14, 1828. Henry Kater. 



LVIII. Expression for the time of Vibration of a simple Pen- 
dulum in a Circidar Arc. By A Correspondent. 

To the Editors of the Philosophical Magazine and Annals. 
Gentlemen, 
T TAKE the liberty of inclosing you an expression for the 
-*■ time of vibration in a circular arc, which does not appear 
to have been noticed by any writer on Dynamics. 

I am, Gentlemen, your humble servant, 

J. W. L. 



Let \J/ be the angle which the pendulum makes with the 
vertical, a. the arc through which it moves, ;• the radius of 
the circle, g the force of gravity, t the time ; then 



dt = xA 



d^ 



2g js/cos^P — cos a 

Let 1 —cos 4/ == (1 — cos a) sin 2 cr 

at- FL - === / 

*/ S n/ (l-cos«) . , V 



'J 



— - — ■ smV v 1— sin 9 - surV 



y sin 4 4~ + cos 4 4-+ 2sin 3 4-cos 2 ~ cos 2cr 
4 4 4 4 



or, 




1 + tan 4 4- + 2tan 2 4" cos 2 <r 
4 4 



^1 + cot 4 4-+ 2 cot 2 -4- cos2cr 
4 4 



Expanding these series by the known methods, and integra- 
ting 



A Letter to William Morgan, Esq. F.R.S. 339 

ting from <r = — — - to <r = + ~ 9 the time of an oscillation is 
given by either of the following series : — 



cos* 

4 



or, 



LIX. A Letter to William Morgan, Esq. F.R.S. on the Ex- 
perience of the Equitable Society. By A Correspondent. 

Dear Sir, 
TJ AVING unfortunately failed, on some former occasions, of 
"■"■ fully comprehending the meaning of your expressions, I 
earnestly intreat your attention to a few remarks on your late 
statement of the Experience of the Equitable Society, in order 
that you may correct, if possible, the exaggerated conclu- 
sions which appear to me to be fairly deducible from the num- 
bers that you have published ; for I have no doubt that you 
will unite with me in sincerely deprecating the dangerous con- 
sequences, that would result from the hasty adoption of these 
conclusions in the practice of life assurance, although they 
may still be very useful as cautions deserving the attention of 
the granters of annuities. 

Your table, lately published, stands thus : 

That is, 



Age. 


Number. 


Died [annually]. 


One in # 


20 to 30 


4720 


29 


163 = 188-25 


30 to 40 


15951 


106 


150=185-35 


40 to 50 


27072 


201 


135 = 180—45 


50 to 60 


23307 


' 339 


69=124 — 55 


60 to 70 


14705 


436 


34= 99-65 


70 to 80 


5056 


219 


17= 92-75 


80 to 95 


701 


99 


7= 94-87 



[View of the Rise and Progress of the Equitable Society, 
8vo 1828. p. 42.] 

1 . I have first to observe, that the numbers of the column 
marked with an asterisc, which vary from 188 to 92, ought 
all, according to Halley's earliest hypothesis, to be 1 00 ; and 
according to Demoivre's correction of that hypothesis, to be 

2X2 86 only. 



340 A Letter to William Morgan, Esq. F.R.S., 

86 only. The mean of the numbers here computed is 137: 
and nearly in the proportion of 86 or 87 to 137 does the ex- 
pectation of life, as exhibited by this table, exceed the estimate 
of the Northampton table: a result not materially differing 
from the proportion of 2 to 3, which you assign. 

2. But a more remarkable peculiarity of the decrements, or 
rather the decremental quotients, derived from your table, is 
the regularity which is observable in their progress after the 
period of middle life; each of the numbers, which express 
them, being precisely or very nearly the half of the preceding 

number. Thus, disregarding fractions, we have — m 67 for 

69, ^- = 34, 5^- = 17, and —■ = 8 for 85, which is equiva- 
lent to 7 at 87^. 

3. We may therefore continue this series with perfect con- 
fidence, until the whole number of lives is exhausted, taking 
the annual decrement at 95, J, at 105,J, and at 115,1, which 
may be supposed to be a sufficient age for the termination of 
our computations. 

4. The decremental quotient in your table, , is very 

nearly — ; y being — — — , x the age, and z the number living : 

for this expression gives us, from 25 to 85, (512, 256,) 128, 
64, 82, 16, 8 : and if we wish to modify the formula, we may 

make it more generally £. — = «y, and y = b — c x; so that 

the computation might be adapted to the earlier ages, if we 
had sufficient documents for the purpose. 

5. We might at once form a table of mortality from the 
quotients thus computed, proceeding downwards from a single 
life at the age of 1 15 : but it will be much more convenient, and 
perhaps equally accurate, to employ the method of fluxions. 

6. Since ~ = a y A x, A x being = 1, y = b — ex, and 
Ay =—cAx, we have -r = a y . :-—•; whence, substitu- 
ting, as usual, -r- for —— , we have the equation -— = a y . —?-■> 
of which the fluent is hlz = a y . — -j — j- /; which becomes, for 

chla •* ' ' 

the values a = \ and c = T \,,/- -^7, or hi* =/- 14 ' 4 ^ 695; 

which, when y is 1 1*5, becomes^/— '0049926; and if we suppose 
the number born to be 100,000, 1 1-5129254 =/— -0049926, 

and 



on the Experience of the Equitable Society. 341 

and/= 11-5179180, and hl«> 11-517918 - ii^^ be- 
ing = i^f— • When y = and z« = 1, hlz = -2-90903 

= h 1 -— -, so that about one in a million only would survive at 

115. 

7. It is obvious that, according to this formula, the value 
of z can never become wholly extinct, and that a population 
may be imagined great enough to have an individual living at 
any given age : but notwithstanding Mr. Gompertz's ingenious 
speculations on patriarchal longevity, it can scarcely be ad- 
mitted that the analogy is sufficiently strong to justify such 
a conclusion respecting more modern times ; to say nothing 
of the population of the whole world as a limit which would 
require to be considered. 

8. The results of the formula are exhibited in the following 
table, in which they are compared with Mr. Babbage's table 
of the Equitable Experience, with the Carlisle table, and with 
the table published in the Philosophical Transactions for 1826. 



Age. 


Living. 


Bx2 


Cx2 


I X-rjr 


Nx-w 


(0 


10000) 










(15 


9900) 










(25 


9761) 










(35 


9490) 










45 


8970 


9612 


9454 


10535 


10827 


50 


8561 


8910 


8794 


9263 


9523 


55 


8014 


8060 


8146 


7928 


8160 


60 


7299 


7084 


7286 


6543 


6793 


65 


6396 


6048 


6036 


5130 


5440 


70 


5310 


4974 


4802 


3733 


4107 


75 


4075 


3876 


3350 


2432 


2773 


80 


2808 


2714 


1906 


1336 


1563 


85 


1654 


1302 


890 


571 


620 


90 


785 


340 


284 


177 


153 


95 


26 


40 


60 


31 


13 


100 


6-1 





18 


7 





105 


•7 







1 




110 


•04 






•3 




115 


•01 












9. I am at a loss to understand how you will be able to 
reconcile the numbers of the first column of this table, with 
the opinion that " the experience of the Equitable Office con- 
firms the accuracy of the Northampton table," which is re- 
presented by the fourth column, on the supposition that a 
given number of individuals about 55 is to be compared. From 
this age, and as far as 85, the first column certainly represents 

the 



342 A Letter to William Morgan, Esq. F.R.S. 

the numbers of your table, if I have not mistaken their import ; 
but the formula may readily be made to extend with equal 
accuracy to ages somewhat above this limit, as well as to an 
earlier period. We may take, for example, 105 for the age 
at which the decremental quotient, indicating the rate of mor- 
tality, becomes = 1, and make it 150 at 35 ; it must then be 
\/ 150 at the intermediate age of 70; and supposing a 10 = 

— , — = 1 '074.2, b being =105, and c = 1, and the fluent 
becomes =/- Tfifcjfi • ~p V being" 1 05 - *, or/- &^ : 

and log a = -031087, and for 10000 at birth,/= 9*218 ; which 
gives, at 95, 11, instead of 26, and at 55, 7207, a number 
nearer to the truth than the former. 

10. If, happily for the welfare of mankind, it should here- 
after appear that any firm reliance ought to be placed on these 
conclusions, or if the formula could be any otherwise modified 
so as to serve for the purposes of calculation, it might be made 
to afford essential assistance in determining the values of two 
or more joint lives ; and by means of a proper table of fluents, 
the labour would be little greater for combinations of lives 
than for single ones, since the sums of the fluents would re- 
present the products of the quantities to be combined; and a 
single table might be computed, which would render the inte- 
gration of the fluent of e a> diy a matter of little difficulty. But 
such an improvement would at present be premature. 

While results like these, however, are fairly deducible from 
the face of the evidence that you have laid before the public, 
you must allow, my dear sir, that any government granting 
annuities would be highly culpable in reckoning on values of 
human life like those which are represented by the Northamp- 
ton tables ; and that any private office has a right to expect, 
beyond such a valuation, a fair percentage for the payment of 
their unavoidable expenses. On the other hand, I do not see 
how it is possible for any assurance office, not returning a 
large share of their profits, to satisfy the public that their terms 
are reasonable, without acting most improvidently for their own 
interests. Such offices as the Equitable are exempt from these 
objections ; and I have not the least doubt of the judgement and 
integrity with which you have long conducted the business of 
that Society, nor of the impropriety of calling on a private 
body to adopt any other regulations than those which are ap- 
proved by its members. But, as a man of science, it is natural 
to hope that you will be ready to allow other men of science 
to partake in the fruits of your researches, and that you will 

be 



Ochsenheimer's Genera of the Lepidoptera of Europe. 343 

be desirous of vindicating yourself from all possible suspicion 
of ambiguity and of inconsistency. 

I am, dear sir, with great respect, yours, &c. 

Waterloo Place, Oct. 13, 1828. * * * *. 



LX. An Abstract of the Characters of Ochsenheimer's Genera 
of the Lepidoptera of Europe; with a List of the Species of 
each Genus, and Reference to one or more of their respective 
Icones. By J. G. Children, F.R.S. L. % E. F.L.S. $c. 

[Continued from p. 287-] 

Genus 9. LYCiENA, Fab. 
Thecla et Hesperia, Fab. Polyommatus, Latr. 

Argyreus, Argus, Pterourus, Battus etGRAPHiUM, Scop. 
Cupido, Schrank. Rustici, Hiibn. 

Fam. A. — Legs, first pair shorter than the rest. 

Wings, upper surface generally blue, especially in the males ; 
in the females often brown, with a row of reddish-yellow 
spots near the exterior margin; under surface almost 
constantly grayish, with numerous ocelli with black pu- 
pils surrounded by white irides*. 

Antennce filiform, terminated by an elongated, compressed club. 

Larva onisciform ; head black, and, as well as the feet, very 
small, and scarcely perceptible; the body laciniate as 

* Latreille at first subdivided his genus Polyommatus into three great 
groups, — les pctits-porte~queue, les argus, and les bronzes ; and subsequently 
he established several smaller sections in each of those subdivisions. Mr. 
Stephens has arranged the British Lyccenidtu in the three genera Thecla, 
Lyccena, and Polyom?natus, including in the first, those insects "distin- 
guished by the sombre tints of the upper surface of their wings, and the 
pale streaks with which they are adorned below j by the pubescence of the 
eyes, the abbreviated, triangular anterior wings, and the ovate-triangular 
posterior ones, which are usually furnished near the anal angle with one or 
more short linear tails, or are strongly denticulated on that part." — "The in- 
digenous Lyccence are known by the brilliant coppery tints which adorn the 
greater portion of the disc of the upper surface of the wings f* and though 
considerable diversity of habit and form prevails amongst the Polyovimati t 
they are in general distinguished by the rich blue tints with which their wings 
are enlivened. 

The Lyccence, he adds, are further discriminated from the Theclce by 
their naked eyes, and by the want of the tail-like appendages to their pos- 
terior wings; and from the Polyommati, by the abrupt obtuse club of the 
antennae, the more evidently denticulated posterior wings, and the superior 
size of the pulvilli, or foot-cushions. — The antennas of Stephens's Poly- 
ommati have an abrupt compressed club, terminating in a lateral point ; 
those of the Theclce have the club elongate, cylindric-oval.— See Illustr. of 
Brit. Entom. vol. i. (Haustellata), p. 75 — 83. 

usual, 



344 Mr. Children's Abstract of the Characters of 

usual, the back elevated, and generally beautifully co- 
loured. 

Pupa rather long, naked; colour whitish, with some dusky 
spots on the back and side. 

Metamorphosis usually on the stem of a plant ; rarely under 
the surface of the ground. 

Species. Icon. 

a. No transverse reddish-yellow fascia on the under surface 

of the posterior wings. 

1. L. Arion, Linn. Ernst, I. PI. XLI. f. 36. d.e.f. 

2. — Alcon, Fab Ernst, I. PI. XLI. f. 86. i. k. 

PI. LXXXIII. Suppl. II. 
PI. 4. f. 80. a.— d. tert. 

3. — lolas, Ochs.* 

4. — Euphemus, Hiibn. Ernst, I. PI. XLI, f. 36. g. h. 

5. — Erebus, Fab Ernst, I. PI. XL. f. 86. a— c. 

6. — Cyllarus, Fab Ernst, I. PI. XLI. f. 86. o. 

7. — Acts, Ochs Ernst, I. PI. XLII. f. 88. a— d. 

8. — Argiolus, Linn.... Ernst, I. PI. XLI. f. 86. 1. m. 

9. — Damon, Fab Ernst, I. PL XLII. f. 87. a— d. 

10. — Alsus, Fab Ernst, I. PI. XLII. f. 88. e. f. 

11. — Lysimon, Hiibn. . Hiibn. Pap. Tab. 105. f. 534. 535. 

(mas.) 

12. — Pheretes, Hiibn. . Hiibn. Pap. Tab. 97. f. 495.496. 

(mas.) Tab. 107. f. 548. 549. 
(fcem.) 

13. — Dapknis, Hiibn. Ernst, I. PI. XXXVIII. f.81. a. b. 

b. A transverse fascia of orange-coloured spots on the under 

side of the posterior wings, near the outer margin. 

14. __ Corydon, Fab Ernst,I. PL XXXIX. f. 83. a— d. 

15. — Dorylas, Hiibn... Ernst,I. PLLXXXIII.Suppl.il. 

PL IV. f. 82. a— d. bis. 

16. — Adonis, Fab Ernst, I. PL XXXIX. f. 82. a— e. 

17. — Icarius, Esp Hiibn. Pap. Tab. LIX. fl 283. 

(mas.) 284. 285. (fcem.) 

18. — Alexis, Hiibn.... Ernst, I. PL XXXVIII. f. 80. g.h. 

19. — Eros, Ochs Hiibn. Pap. Tab. 108. f. 555. 556. 

( Tith onus, Hiibn . ) (mas.) 

20. — - Orbitulus, Esp.... Hiibn. Pap. Tab. 103. f. 522. 523. 

(mas.) 524. 525. (fcem.) 

21. — Agestis, Hiibn.... Hiibn. Pap. Tab. 62. f. 303. 304. 

(mas.) 305. 306. (fcem.) 

* Sp. n. — L. alis integris cceruleis, maris immaculatis, foeminae fuscis, disco 
coeruleo, subtus cinereis, lunula media strigaque punctorum nigrorum ocel- 
larium. 

22. L. Eu- 



Ochsenheimer's Genera of the Lepidoptera of Europe, 345 

Species. Icon. 

22. L. Eumedon, Hubn.. Hubn. Pap. Tab. 62. f. SOI. 302. 

(mas.) 138.f.700.701.(fcem.) 

23. — Admetus, Hlibn... Ernst, I. PI. VI. Suppl. III. f. 80. 

a — d. quart. 

24. — Optilete, Hubn... ErnstJ. Pl.LXXXIV. Suppl.II. 

PL 5. f. 85. a— c. tert. 

25. — Arg?is, Linn Hubn. Pap. Tab.64. f.316.(mas.) 

(var. Acreon, Fab.) 317. 318. (fcem.) 

26. — Aegon, Hubn Hubn. Pap. Tab.64. f. 313.(mas.) 

314.315. (fcem.)* 

27. — Amyntas, Fab. ... Ernst, I. PL XXXVI I. f. 78. a— d. 

28. - Polysperchon, \ ^ pJ xxx £ b> 

x5cr°'stra6s. ...... [ 

29. — JFfy&$ Fab.' Ernst, I. PL XL. f. 85. e. f. 

30. — Battus, Fab ErnstJ. Pl.LXXXIV. Suppl.II. 

PL 5. f. 85. a-— c. bis. 

Fam. B. — The upper surface of the wings usually of a reddish- 
gold, or copper colour, often with black maculae; the 
under surface always spotted ; the posterior wings with 
an orange-coloured plain fascia, or composed of a series 
of maculae, near the posterior margin; anal extremity 
usually distinctly angular. 

Larva, generally longer than those of the preceding family; 
usually pale green, and villose ; hairs reddish ; head light 
brown, or brownish-white. 

Pupa brownish, usually obtuse at each end ; suspended hori- 
zontally by threads attached to the neck and posterior 
extremity. 

Species. Icon. 

31. L. Helle, Fab ErnstJ. Pl.LXXI. Suppl.XVII. 

f. 89. a — c. bis. 

* Ochsenheimer also quotes, inter alia, (though with a note of doubt,) 
Lewin's Ins. pi. 39. f. 8. 9, as icons of his L. JEgo?i> which, according to 
Haworth, represent Papilio {Lyccena) Artaxerxes. Through the kindness of 
James Wilson, Esq. of Woodville, Canaan, near Edinburgh, and author of 
the beautiful Illustrations of Zoology now in course of publication, my ca- 
binet is rich in specimens of that singularly local and rare insect, by com- 
paring which with Ochsenheimer's specific characters of L. JEgon, it is ob- 
vious that he never saw the true L. Artaxerxes. I subjoin his sp. ch. of 
L. JEgon, and the very accurate one of P. Artaxerxes, as given by Mr. Ha- 
worth. 
L. Acson. Alis integris cceruleis margine lato nigro ; subtus ccerulescenti- 

albidis, punctis ocellaribus : posticis fascia ferruginea ocellisque cceru- 

leo argenteis marginalibus. — Ochs. Schm. von. Eur. I. part 2. p. 57. 
P. Artaxerxes. Alis nigris, anticis puncto medio utrinque albo, posticis lunu- 

lis rufis, subtus margine albo rufo punctato. — Haw. Lep. Brit. p. 47. 

No. 62. 

New Series, Vol. 4. No. 23. Nov, 1828. 2 Y 32. L. Circe, 



346 Mr. Children's Abstract of the Characters of 

Species. Icon. 

32. L. Circe, Hiibn Ernst, I. PL XLIII. f. 89. a— d. 

33. _ TJiersamon, Fab.. Hiibn. Pap. Tab. 69. f. 346. (mas.) 

347. 348. (foem.) 

34. _ Gordius, Hiibn. . Ernst,I.Pl.LXXII.Suppl.XVIIL 

f. 91. a. b. bis. P1.LXXIII. 
Suppl. XIX. f. 91. c. d. bis. 

35. — Hipponoe, Esp... Ernst, I. -PL XLIV. f. 92. a. b. 

PI. LXXII. Suppl. XVIII. 
f. 92. f. g. 

36. — Chryseis, Fab ErnstJ.Pl.LXXIII.Suppl.XIX. 

f. 93. a — g. bis. 

37. — ■ Ewybia, Ochs.... Hiibn. Pap. Tab. 68. f. 339. 340. 

(mas.) 341.342. (foem.) 

38. — Hippothoe, Linn.. Ernst, I. PL XLIII. f. 91. c. d. 

PL XLIV. f. 93. a— c.f 

39. — Virgaurea, Linn. Ernst, I. PL XLIV. f. 92. c— e. 

40. — Phleas, Linn Ernst, I. PL XLIII. f. 91. a. b. 

PL LXXII. Suppl. XVIII. 
f.91. e.g. h. 

41. — Battus, Fab Hiibn. Pap.Tab.l 07. f.550. (mas.) 

Tab. 72. f. 360. 361. (foem.) 

42. — Bubi, Linn Ernst, I. PL XLIII. f. 90. a.b. 

Fam. C. — The posterior wings subcaudate, with generally one 

or more reddish-yellow maculae above the short tail ; a 
white transverse fascia (more or less distinct) either sim- 
ple, or composed of minute maculae on the under surface 
of both wings. 

Larva similar to those of Fam. A., but less elevated, and 
rather broad at the fore-part; back hairy; hairs very 
fine and short. 

Pupa flat beneath ; back very convex ; generally attached to a 
leaf by a web, and filaments across the back. 
Species. Icon. 

43. L. Roboris, Esp Hiibn. Pap. Tab. 73. f. 366. 367. 

(foem.) 

44. — Quercus, Linn. ... Ernst, I. PL XXXV. f. 71. a— c. 

45. — Bosticus, Linn.... Ernst, I. PL XXXVII. f.76. a.b. 

PL LXXI. Suppl. XVII. 
f. 76. c. 

46. — Telicanus, Hiibn. Hiibn. Pap. Tab. 74. f. 371. 372. 

(mas.) Tab. 108. f. 553. 554. 
(foem.) 

f 38*. L. Dispar, Haw Curtis, Brit. Ent. I. PI. 12. $ &? . 

Mr. Stephens observes, that this species may eventually prove to be the 
same as L. Hippothoe. Ochsenheimer has omitted it altogether. 

47. L. Spini, 



Ochsenheimer's Genera of the Lepidoptera of Europe. 347 

Species. Icon. 

47. L. Spirit, Fab Ernst, I. PI. XXXVI. f. 74. a. b. 

48. — Ilicis, Hiibn Ernst. I. PL XXXV. f. 72. a. b.? 

PI. XXXVI. f. 75. a. b. 

49. — JEsculi, Ochs Hubn. Pap. Tab. 109. f. 559.560. 

(mas.) 

50. — Acacice, Fab Herbst, Schm. Tab. 308. f. 3. 4. 

51. — W. album, Knoch. Ernst, I. PI. LXXXII. Suppl. II. 

PI. 3. f. 72. a— c. bis. 

52. — Pruni, Linn Ernst, I. PL XXXVI. f. 73. a— f. 

53. — Betulce, Linn Ernst, I. PL XXXV. f. 70. a— f. 



Genus 10. PAPILIO, Fab., Lat. 
Pterourus, Scop. Pieris, Schrank. Principes, Hubn. 

Legs six, perfect (formed for walking). 

Wings, exterior margin of the anterior wings longer than the 
interior; posterior wings caudate, and excised to allow 
freedom of motion to the abdomen, or grooved to re- 
ceive it. 

Antennce filiform, terminated by an oval obtuse club. 

Larva fleshy ; head obtuse, small ; neck furnished with a fur- 
cate, retractile organ. 

Pupa angular, anteriorly bifurcate, fastened by a transverse 
thread. 

Metamorphosis in the air. 

Species. Icon. 

1. P. Ajax, Linn Esper, Schm. I. Th. Tab. LI. 

Cont. I. f. 1. 

2. — Podalirius, Linn. Ernst, I. Pl.XXXIV. f.69. a— d. 

3. — Machaon, Linn. .. Ernst, I. PL XXXIV. f.68. a— e. 

Genus 11. ZERYNTHIA, Ochs. 
Thais, Fab., Latr. Argyreus, Scop. Pieris, Schrank. 
Legs six, perfect (formed for walking). 
Wings, posterior elongated, dentate, ecaudate. 
Antennce short ; knob oval ; apex slightly pointed. 
Larva similar to those of the preceding genus in form, with 
the segments of the body furnished with rows of stiff hairs. 
Species. Icon. 

1. Z. Polyxena, Hubn. . Ernst, I. PL LII. f. 109. a. b. 

2. — Medesicaste, Illig. Ernst, 1. PL LXXVIII. Suppl. 

XXIV. f. 109. a— d. bis. 

3. — Bumina, Linn. ... Hiibn. Pap. Tab. 124. f. 633. 634. 

(mas.) 
2 Y 2 Genus 



348 Mr. Children's Abstract of the Characters of 

Genus 12. DORITIS, Fab. 

Paunassius, Latr. Pieris, Schrank. 

Argus et Battus, Scop. 

Legs six, perfect. 

Wings rather long, partially diaphanous; posterior excised, 

not enveloping the body. 
Body very short, thick,- and hairy; the females with a strong, 
carinated, concave membrane on the posterior segment of 
the abdomen. 
Antennce short ; club elongated oval, straight. 
Larva with tentacula, and nearly of equal thickness through 

its whole length, hairy, hairs short. 
Pupa, oval, folliculated, inclosed in a thin web. 

Species. Icon. 

1. D. Apollinus, Herbst. Ernst, I. PL LXXVI. Suppl. 

XXII. f. 99. a— d. quart. 

% — Apollo, Linn Ernst, I. PL XLVII. f. 99. a— h. 

PL LXXV. Suppl. XXI. 
f. 99. a. b. bis. 

3. — Delias, Esp Hubn. Pap. Tab. 110. f. 567. 568. 

(mas.) 

4. — Mnemosyne, Linn. Ernst, I. Pl.XLVlII.f.lOO.a— c. 

Genus 13. PONTIA, Fab. (Steph.) 

Pieris, Latr., Schrank. Battus et Ascia, Scop. 

Mancipia, Hubn. 

Legs six, alike in both sexes. 

Wings entire, opaque; anterior somewhat triangular, some- 
times rounded at the tip, generally white, with some black 
spots ; posterior rounded, with a groove on the inner mar- 
gin to receive the abdomen, beneath often coloured yel- 
lowish or greenish. 

Antennce with an abrupt, obconic, compressed club. 

Larva with a small, round head ; body slender, tapering at 
each end, downy. 

Pupa angular, acuminated in front, supported by transverse 
threads on the middle and posterior portion of the body # . 

1. P. Cra- 

* Mr. Stephens, in his Illustration?, observes that the insects of this Genus, 
" from the simplicity of their colouring, and their common appearance, have 
been unworthily neglected in this country by collectors; and in consequence 
we still remain unacquainted with the history and metamorphosis of some 
of the species, which evidently are far from uncommon." Mr. Stephens has 
examined this group with considerable attention, and has been induced in 
consequence to introduce as distinct species, certain individuals which have 

hitherto 



Ochsenheimer's Genera of the Lepidoptera of Europe, 849 

Species. Icon. 

1. Po. CraUegi, Linn.... Ernst,I. Pl.XLVIII.f. 101. a— f. 

2. — Brassier, Linn... Ernst, I. PL XLIX. f. 102. a—e. 

3. — Rapce, Linn Ernst, I. PL XLIX. f. 103. a— d. 

4. __ Napi, Linn Ernst, I. PL L. f. 104. a. b. 

5. — Callidice,Hubn... Hiibn. Pap. Tab. 81. f. 408.409. 

(mas.) Tab. 108. f. 551. 552. 
(fcem.) 

6. — Raphani, Fab. ... Esper,Schm.I.Th.Tab.LXXXIV. 

Cont. XXXIV. f. 3. (mas.) 
Tab.CXXIII. Cont.78.f.3. 
(mas.) 4. (fcem.) 

hitherto been considered merely as varieties of long established species : — 
for instance, the smaller variety of Po. Brassicce constitutes his species Cha- 
riclea. Now it has been generally considered, that the chief difference 
between the larger and smaller varieties of Po. Brassicce consists in size and 
colour; to explain which, it is observed that the larger are the aestival, 
and the smaller the vernal brood ; and that the paler colours and smaller 
size of the latter are owing, the one, to the solar rays not being sufficiently 
powerful, when the insect comes forth, to produce the intense hue so con- 
spicuous in the supposed aestival brood of Po. Brassicce ; the other, to the 
diminution in bulk, which the animal is presumed to sustain in consequence 
of the longer period that it remains in the pupa state, namely, from Septem- 
ber to April ; whereas the aestival brood remains in that state a few days 
only. To these explanations Mr. Stephens objects, that Po. Brassicce also 
occurs early in the month of May, so that the difference of the sun's influ- 
ence can, in those cases, amount to little. And as to the supposed alter- 
nating increase and diminution of size in the vernal and aestival broods, it is 
an anomaly in Zoology, "unless Po. Rapes and Metra offer an example; 
but these insects, I presume, are distinct, upon similar grounds to those 
which appear to separate the insects that have promoted these observa- 
tions." — Stephens. These grounds are, at least as to Po. Brassicce and Cha- 
riclea y that thelatter is considerably smaller than the former; Po. Brassicce has 
the tip of the anterior wings above, black, and the patch on its inner edge 
indented, the points of the indentations following the direction of the ner- 
vures, and the extreme tip being slightly irrorated with white, with the cilia 
waved with black and yellowish ; Po. Chariclea has the tip ash-coloured, 
without any internal indentations; the cilia with which it is fringed are pale, 
and the under surface of the posterior wings of a deeper yellow and moro 
thickly irrorated with dusky, than those of Pontia Brassicce. Stephens di- 
vides his genus into two sections, — the first containing " the true Pontice; 
the second, those insects which, if necessary to create {them) into a new 
genus, may, after Hiibner, be termed Mancipia" 

The following are his characters of the two sections : 
" A. With the terminal joint of the palpi longer than the second : the apex 
of the anterior wings obtusely angled : the posterior wings not varie- 
gated beneath : the pupa strongly angulated, with a distinct short pro- 
cess in front, and projecting lateral appendages in front of the wing- 
cases (Pontia)." 
" B. With the terminal joint of the palpi shorter than the second : the an- 
terior wings distinctly rounded at the tip : the posterior variegated be- 
neath: the pupa angulated, with an elongated acute process or beak 
in front : lateral appendages wanting (Mancipium)." 

7. P. Chlo- 



350 Mr. Children's Abstract of the Characters of 

Species. Icon. 

7. P. Chloridice, Hubn. Hiibn. Pap. Tab. 141. f. 712. 713. 

(mas.) 714. 715. (fcem.) 

8. — Daplidice, Linn.. Ernst, 1. PI. L. f. 106. a— c. 

Curtis, Brit. Ent. I. PL 48. 
(figura optima.) 

9. — Glance, Hiibn. ... Hiibn. Pap. Tab. 107. f. 546. 547. 

(mas.) 

10. — Bclemia, Hiibn... Hiibn. Pap. Tab. 82. f. 412. 413. 

(fcem.) 

11. — Belia, Fab Hubn. Pap. Tab. 83. f. 417. 418. 

(fern.) 

12. — Ausonia, Hubn... Hubn. Pap. Tab. 113. f. 582. 583. 

(fcem.) Tab. 83. 416. (mas.) 

13. — Tagis, Hubn Hiibn. Pap. Tab. 110. f. 565. 566. 

(mas.) 

14. — Cardamines,\Avm. Ernst, I. PI. LI. f. 107. a — k. 

15. — Eupheno, Linn.... Ernst, I. PI. LI I. f. 108. a. b. e. f. 

PLLXXVILSuppl. XXIII. 
f. 108. g. h. 

16. — Sinapis*, Linn... Ernst, I. PI. L. f. 105. a — c. 

Genus 14. COLIAS, Fab., Latr. 

Argyreus et Battus, Scop. Pieris, Schrank. 

Legs six, alike in both sexes, moderate, slender. 

Wings, anterior somewhat triangular, posterior rounded, with 

a groove to receive the abdomen. 
Antenna? short, rather slender, filiform at the base, towards 

the tip gradually thickening into an obconic club. 

* On this species Stephens has formed a new Genus, which he has called 
Leucophasia. Its characters are as follows : 

"Genus 5. LEUCOPHASIA , mihi. 

"Antenna with an abrupt, obconic, compressed club; palpi very short, de- 
pressed, three-jointed, the basal joint large, conic, the second small, 
quadrate, the terminal one minute, globose: wings opaque, suborbicu- 
lar, the discoidal cell small, basal ; posterior wings slightly grooved : 
legs alike in both sexes, moderate \ claws distinct, bifid. Caterpillar 
cylindric, downy. Chrysalis angulated, fusiform, supported by a trans- 
verse thread." — lllust. Brit. Entom. (Haustellata), vol. i. p. 24. 
Stephens refers Po. Cratcegi to the genus Pieris, which he adopts as di- 
stinct from Pontia; and in the latter genus he inserts as separate species 
Napcea, Hiibn., and Bryonia, Wallner, both of which Ochsenheimer con- 
siders (though with a note of doubt) as varieties of Napi; and Stephens 
himself suspects also, that the former may possibly be nothing more. He 
has substituted Petiver's name of Sabcllica for that of Bryonia, adopted by 
Wallner on the score of priority. 

a AiVKog, albus ; (petai^, apparitio. 

Larva 



Ochsenheimer's Genera of the Lepidoptera of Europe. 351 

Larva elongated, nearly cylindrical, hairy, but the hairs so 
short that they appear naked; back pale, or dark green, 
no central, longitudinal stripe. 
Pupa acuminated in front, gibbous, subangulated, fastened by 

a transverse thread. 
' " The Coliades are particularly gay and showy insects ; they 
are eminently distinguished by the brilliant tints of orange and 
yellow with which their wings are adorned ; they are of mode- 
rate size, and usually appear in their final state towards the 
autumn." — Stephens, 

Fam. A. — Wings rounded, margin generally dark-coloured. 
Species. Icon. 

1. C. Edusa, Fab Ernst, I. PI. LIV. f. 111. a-e. 

2. — Aurora, Fab Ernst, I. PI. VIII. Suppl. III. 

f. 111. quint. 

3. — Myrmidone, Hubn. Ernst, I. PI. LXXVIII. Suppl. 

XXIV. f. 111. a. b. bis. 

4. — Chrysotheme, Hubn. Ernst, I. PL. LXXVIII. Suppl. 

XXIV. f. 111. a. b. tert. 

5. _ Phicomone, Hubn. Ernst, I. PI. LXXIX. Suppl. 

XXV. f. 112. a— c. bis. 

6. — Hyale, Linn Ernst, I. PI. LIV. f. 112. a. b. 

7. __ Palceno, Linn Ernst, I. PI. VI. Suppl. III. 

f. 111. a. b. quart. 
Fam. B. — Wings somewhat angular*. 

8. C. Rhamni, Linn Ernst, I. PI. LIU. f. 110. a— e. 

Curtis, Brit. Ent. PL 173. 

9. — Cleopatra, Linn.... Ernst,I. Pl.LIII.f.ll0.f.g.(mas.) 

Genus 15. HECAERGE, Ochs. 
Libythea, Fab. Nymph alis, Late. 

Legs four, perfect. 

Wings angular, dentate, dark coloured with lighter spots. 

Antennce short, rigid, fusiform. 

Palpi very long, porrected, straight. 

Species. Icon. 

1. H. Celtis, Fab Ernst, I. PL I. Suppl. III. f. 5. 

a — f. bis. 
f Only one Europaean species. 

* Genus Gonepteryx, Leach. 
" Antennce short, stout, very gradually thickening into an obconic club ; 
palpi short, much compressed, the terminal joint very short ; wings 
angulated, large, the posterior grooved to receive the abdomen : legs 
alike in both sexes, short, stout ; claws minute, bifid. Caterpillar naked. 
Chrysalis angulated, acuminated in front ; fastened with a loose thread 
round its middle." — Stephens t l\\ust. Brit. Entom. (HaustellAta), 
vol. i. p. 8. Genus 



352 Mr. Children's Abstract of the Characters of 

Genus 16. HESPERIA, Latr. 

Thymele, Pamphila, Fab. (Steph.) Battus, Scop. 

Erinnys, Schrank. Urbani, Hiibn. 

Legs six, perfect (formed for Walking.) 

Wings, anterior either short, broad, triangular, and rounded 
posteriorly (Thymele, Steph.), or nearly triangular, 
and slightly elongate (Pamphila, Stephens); posterior 
broad, rounded, triangular, entire, or slightly denticu- 
lated (Thymele, Steph.), or rather ovate-triangular, with 
an obsolete emargination on the hinder margin, and some- 
times a rudiment of a tail at the anal angle (Pamphila, 
Steph.). 

Antenna short, a little elongate, with a curved, fusiform club, 
not terminating in an acute hook (Thymele, Steph.), or 
not very long, with an abrupt, fusiform club, varying 
slightly in form, and terminated generally in a hook 
(Pamphila, Steph.). 

Head large. 

Body short, thick. 

Larva, naked (Thymele, Steph.), or pubescent (Pamphila, 
Steph.). 

Pupa, with the head-case notched (Thymele, Steph.), or 
with the front acuminated (Pamphila, Steph.). 

Species. Icon. 

1. H. Malvarum, Hoff- 1 -^ . T m -%tt \tt c ™ 

'-. * > Ernst, I. PI. XL VI. f. 98. a— c. 
mannsegg. U.* ,.»J ' 

2. — Lavatercc, Hubn. Ernst,I. Pl.LXXV. Suppl.XXI. 

f. 98. d. e. 

3. — Tessellum, Hubn. Hubn. Pap. Tab. 93. f. 469. 470. 

(mas.) 

4. — Sidcc, Fab Ernst, I. PI. VII. Suppl. III. 

f. 97. a. b. quart. 

5. — Carthami, Hiibn. Ernst, I. PI. VII. Suppl. III. 

f. 97. quint. 

6. — Alveus, Hubn. ... Hubn. Pap. Tab. 99. f. 506. (fcem.) 

7. — Fritillum, Hiibn. Hubn. Pap. Tab. 92. f.461. (mas.) 

462. 463. (fcem.) 

8. — Alveolus, Hubn.f Hubn. Pap. Tab. 92. f. 466. 467. 

(fcem.) 

9. — Proto, Ochs Esper,Schm.I.Th.Tab.CXXIII. 

Cont.78. f. 5. (mas.) f. 6. (fcem.) 
10. — Sertorius, Illig. ... Hiibn. Pap. Tab. 95. f. 471. 472. 

(fcem.) 

* Pa. Malvce, Fab.— Thymele, Steph. f Thymele, Steph. 

11. H. Encrate, 



Ochsenheimer's Genera of the Lepidoptera of Europe. 353 

Species. Icon. 

11. H. Eucrate, Ochs. ... Esper, Schm. I. Th. Tab. 

CXXIV. Cont. 79. f. 6. 

12. — Tages, Linn.* ... Ernst, I. Pl.LXXV.Suppl.XXL 

f. 97. a. b. bis. 

13. — Pumilio, Illig Hiibn. Pap. Tab.91. f.458. (mas.) 

459. 460. (fcem.) 

14. — Steropes, Hiibn.... Ernst, I. PI. LXIV. f. 94. a. b. 

15. — Paniscus, Fab.f Ernst, I. PI. XLV. f. 96. a. b. 

16. *- Sylvius, Fab.f ... Ernst,I. Pl.LXXIV. Suppl.XX. 

f. 96. e. f. 

17. — Comma, Linn.f... Hiibn. Pap.Tab. 95. f. 479. (mas.) 

480. 481. (fcem.) 

18. — Sijlvanus, Fab.f... ErnstJ. PI. XLV. f. 95. a— d.g.h. 

19. — tinea, Fab.f Ernst, I. PL XLV. f. 95. e. f. 

20. — Lineola, Ochs. ... Hiibn. Pap. Tab. 130. f. 660. 661. 

(mas.) 662. 663. (fcem.) 

21. — Actceon, Hiibn.... Hiibn. Pap. Tab. 96. f. 488.489. 

(mas.) 490. (fcem.) 

Genus 17. CHIMERA, Ochs. 
Atychia, Latr. Stygia, Godart. % 

Wings, anterior short, small, of nearly equal length through- 
out ; posterior rounded. 
Head small. 

Antennae bipectinate in the male, simple in the female (Latr.).§ 
Palpi, labial rising remarkably above the clypeus, anteriorly 

very hirsute. (Latr.) 
Antlia very short, or wanting. 
Abdomen posteriorly elongated. 
Tibice, with elongated scales and calcaria. (Latr.) 
Larva, unknown. 

Species. Icon. 

1. Ch. Pumila, Ochs. ... Hiibn. Nocture, Tab. 86. f. 405. 

Q Ai-i, 1 Ernst, III. PI. CII. f. 149. a— c. 

2. - Appendiculata, I fam) yL pL CCLX X1II. 

Ucns>11 j f. 438. a— c. 

* Thymele, Steph. f Pamphila, Steph. 

% Histoire Naturelle des Lepidopteres, ou Papillaris de France, vol. iii. p.167- 
Although this volume is dated 1822, and the fourth of Ochsenheimer's 
work appeared six years before, Godart does not seem to have been aware 
that the German author had in this, his last volume, adopted Latreille's, or 
rather Draparnaud's Genus Stygia, for the reception of HUbner's Bombyx 
Terebellum, which he accordingly transferred from its former place with the 
Chimerae (vol. ii. p. 6. No. 4. Ch. leucomelas) to that Genus. 

§ Ochsenheimer's generic characters in this and several other instances 
are so insufficient, that I have often found it necessary, as in the present 
case, to quote other naturalists of acknowledged authority. 

|| Noct. Chimcera, Hiibn. Pyrctl. Vahliana, Fab. 
New Series. Vol. 4. No. 23. Nov. 1828. 2 Z 3. Ch. 



354 Ochsenheimer's Genera of the Lepidoptera of Europe. 

Species. Icon. 

3. Ch. Radiata, Ochs.... — — — 

4. — Lugubris, Ochs. # Hiibn. Bombyces,Tab.51.f.217.(mas.) 

Genus 18. ATYCHIA, Ochs. 

Procris, Fab., Latr. Aglaope, Latr. Glaucopis, Fab., Latr. 
(Ino, Leach, Stephens.) Chrysaores, Hiibn. 

JVmgs oblong, ciliated ; submarginal cell of the inferior closed 
behind by a very angular nervure, from which three 
branches proceed, and terminate at the posterior margin. 
(Godart.) 

Antennce bipectinate in the male, simple in the female. (Latr.) 

Palpi short, scarcely or not at all rising above the clypeus, 
densely clothed with scales, not hirsute. (Latr.) 

Tibice scaly ; posterior with small calcaria, and the two upper, 
interior spines very minute, or obsolete. (Latr.) 

Larva, short, thick, nearly naked ; head small. 

Pupa soft, with moderately long wing-cases. 

Species. Icon. 

Fam. A. 1. A^ Infausta^ J j^ m R Qm f# 152> a# ^ 

Fam. B. 2. — Prww/, Fab. Ernst, III. PI. CIII. f. 151. a— e. 
3. — Globula- \ Hiibn. Sphing. Tab. 1 . f. 2. (mas.) 
ria 9 Hiibn.... j 3. (fcem.) 

4 ' ^^ C€S ^\^P^llh Pl.CIII.f.l50.a-d. 

[To be continued.] 



Note.— The reader is requested to attend to the following corrections of some 
of the preceding synonyms. 
Gen. Argynnis20. for Fab. read Hiibn. Gen. HipparchiaSS. ) -,-p^ rmd IIUbn 

57. ) J • 



Hipparchia 1. — Fab. — Hiibn. 
3. — Linn. — Hiibn. 

Fab. — Herbst. 



.1:1- 



** £ - Fab. - Hiibn. 
23. — Fab. — Esper. 



60. — Fab. — Thunb. 

65^- Fab -- Es P- 
69. — Fab. — Hiibn. 
77. — Fab. — Pallas. 



* Bomb, lugubris, Hiibn. 
f Genus Aglaope, Latr. 
A. lingua nulla, aut obsoleta. Palpi minimi, articulo ultimo subgraciliore, 
minus squamato. Tibice posticae calcaribus spinisque brevissimis, sub- 
obsoletis. Anus imberbis. Latr. Gen. Crust, ct Ins. iv. 214. To which 
may be added : Antennce sexu utroque bipectinatce ; ala? oblongae, cel- 
lula marginali inferiorum postice clausa, ramisque duobus nervosis, ad 
lineam sepimenti sese invicem decussantibus, longitudinaliter divisa. 
(Godart.) 
J This and the preceding species are placed by Stephens in the Genus Ino, 
Leach, "established by Fabricius by the name of Procris; but that having 
been preoccupied, Dr. Leach changed its appellation to the one it now 
bears." The generic characters of Ino are given by Mr. Stephens as follows: 

"Ino, 



[ 355 ] 

LXI. Notice of the Geological Features of a Route from Madras 
to Bellary , in April and May 1822. By Capt.W. Cullen, 
of the East India Company's Artillery service*. 

T BEG to submit to the Society an attempt to describe the 
* geological features of a route which 1 lately passed over 
from Madras to Bellary. It accompanies a small collection 
of specimens of the prevalent rocks, and a barometrical sec- 
tion, which combined will, I hope, assist in affording some idea 
of the nature of the tracts in question. 

The high road to Bellary was followed as far as Cuddapah ; 
but from thence going north, by Chinnoor Nundialpett Poon- 
namila to Iddamacul, my route, from the last-mentioned vil- 
lage, lay nearly west by Giddeloor, over the Nulla Mulla range 
of hills by the Nundi Kunnuwi Ghaut f, by Ban aganap illy, 
Piaplee, and Gootty, to Bellary. A great proportion of this 
route must, in favourable weather, be as beautiful in point of 
scenery, as it is ricli in geological interest ; but at the period 
of my passing (the latter end of April and beginning of May), 
the excessive heat had checked all vegetation, and afforded but 
little inducement for excursions in quest of mineralogical spe- 
cimens. 

Referring the route to Arrowsmith's large map, which is 
sufficiently correct for the present purpose, it will be observed 
to offer an obvious distribution into five portions, each of them 
characterized by distinct geographical features. 

First. The plain open tract from Madras to Naggery. 

Second. The narrow mountainous belt extending from Nag- 
gery to the neighbourhood of Cummum. 

" Ino, Leach. — Antennce gradually thickening from the base to near the 
apex, straight, bipectinated, or simple, with the interior edge subserrated : 
palpi short, not reaching beyond the clypeus, densely clothed with scales : 
head, thorax, abdomen, and femora, thickly covered with scales, rather elon- 
gate on the former. Larva scaly, depressed j head small : pupa with long 
wing-cases." 

" The species are known from the Anthocerae (Zygaenae) by the form of 
the Antennae, which are not curved, but nearly straight, and become gra- 
dually thicker as they approach the tip, which is again slightly attenuated ; 
the males have this part bipectinated, and the females simple, but ser- 
rated beneath ; the species (of which there are several on the continent) 
are all of rich tints of light green, blue, or brownish, and immaculate." — 
Must. Brit. Ent. (Haustellata), vol. i. p. 105. Stephens gives only one species, 
(Statices, Linn.) as decidedly British : that considered as Globularice, Hiibn. 
having, on examination, proved to be referable to Ino Statices, var. /3. 
He conceives, however, that it is extremely probable that Ino Globularice 
may occur in England. 

* From the Transactions of the Literary Society of Madras. Part I. 

f Kunnuwi is Kanarese for Ghat. Nundikunnuwi means, therefore, 
Nundi Ghat. 

2 Z 2 Third. 



356 Capt. Cullen's Notice of the Geological Features 

Third. The open level country from the Nulla Mulla hills 
to Banaganapilly. 

Fourth. Ihe tract of tabular land between that town and 
Gootty. 

Fifth. The level country from thence to Bellary. 

The geological characters of this tract are equally remark- 
able, and admit of a division corresponding perfectly with its 
geographical features. 

In the first division the prevailing rocks are granite. 

In the second, clay-slate and sandstone. 

In the third, compact blue limestone. 

In the fourth, clay-slate and sandstone. 

In the fifth, granitic. 

I have ventured to characterize each division by one or two 
rocks only, because in each of them the rocks specified were, 
in general, beyond all comparison the most abundant. In the 
several divisions, of course, were found many of those minerals 
by which the principal rocks are usually accompanied; but to 
enumerate the whole of these as they occurred may not be 
deemed necessary, since the specimens themselves are for- 
warded. 

Before entering into a detail of the rocks prevailing in these 
tracts, it may be proper to notice, in a general way, their 
absolute heights above the sea. 

The north-west side of Pootoor, at the distance of sixty- 
four miles from Madras, exclusive of windings, stands about 
500 feet above the sea ; exhibiting a rise of eight feet in the mile ; 
and this proportion holds good throughout that part of the 
route, interrupted only by one undulation on the east side of 
Naggery, and by a second between Naggery and Pootoor. 

These undulations, which rise 100 or 150 feet above the ge- 
neral level, mark the course cf chains of hills, which in such 
places cross the road ; and, in general, in all these sections of 
the terrcpleine of a country, similar abrupt elevations may be 
considered as indications of the presence, and course of a chain 
of hills. There is a third rise a little beyond Pootoor, indi- 
cating like the former, the presence of a mountainous range. 

The valley of Tripetty is, on a mean, about 360 feet above 
the sea, but the river which runs through its centre little above 
300. The mean height of the valley from Baulpilly to Wun- 
timettah, an interval of about 52 miles, is about 550 feet, 
and the town of Cuddapah itself a little below 500. 

Chinnoor on the Pennar river, five or six miles north of 
Cuddapah, is about 30 feet lower than that place; but the 
height of Jungumpilly, the next march, is 700 feet. There 
is then a fall of about 100 feet to the Saghilair river; after 
which it rises gradually to Alinuggar and Iddamacul, both of 

which 



of a Route from Madras to Bellary> in 1 822. 357 

which places are on the same level, about 900 feet above the 
sea. I was much disappointed in the height of the Nulla 
Mulla range, which, at the point where I crossed, did not at- 
tain an elevation of 1800 feet above the sea, and of little more, 
therefore, than 800 feet above the plains on either side. 

The route across the plain, between the Nulla Mulla range 
and the table land at Banaganapilly, is nearly level, and about 
800 feet above the sea; but the general declination of this 
plain appears to be _ from the Kistnah to the Pennar. 

From Banaganapilly to Jeldroogum the ascent along the 
valley is pretty considerable, being 400 feet in about twenty 
miles, or 20 feet per mile. 

The table land, commencing two or three miles west of Jel- 
droogum, and extending to Piaplee, a distance of eight or ten 
miles, is between 1700 and 1800 feet above the sea # ; and 
Colonel Lambton has already stated that to be the mean height 
of the country between Gootty and Bellaryf. 

Although granitic have been mentioned as the prevailing 
rocks in the first division, none of them were seen in situ till 
about the thirty-seventh mile, in the bed of the river at the 
village of Nellatoor. The whole of the previous flat being a 
loose sandy soil, entirely free from rocky masses, and even al- 
most so of fragments, with the exception of some stony swells 
to the north of Cunkama Choultry. I should observe, how- 
ever, that all the pagodas, facings of tanks, &c ., were built 
either of granite or laterite. 

The blocks forming these latter have a rolled appearance, 
are a kind of coarse sandstone conglomerate or breccia, and 
perhaps originate from, or are connected with, the mountain- 
chain running north from Naggery Nose. The granite, which 
first makes its appearance at Nellatoor, may be traced as far 
as Curcumbaddy, with no other interruption save that of those 
singular beds or courses of trap which are apparently so com- 
mon in all the granitic tracts of this country. All these beds 
appear to run nearly east and west. In the present instance 
they were remarkably numerous, forming chains of low hills, 
and crossing the route so frequently, as to occupy a space 
which, taken in the aggregate, would nearly equal that of the 
granite itself. Granite, however, evidently composes the great 
mass of hills, which commence a few miles to the south-west 

* But there is a very rapid descent from Piaplee towards Gootty, of 400 
or 500 feet in the first ten miles. The plains west of Gootty are about 
1200 feet above the sea. 

•f This seems rather under the truth: — barometrical observations, which 
I have since had an opportunity of making, give from 1400 to 1500 feet for 
the mean altitude of the country between Gootty and the Hoggree river, 
eight miles east of Bellary. 

of 



358 Capt. Cullen's Notice of the Geological Features 

of Naggery, and which continuing near to the left of the road 
as far as Woramallipett, then stretch off to the west, till they 
are lost in the prolongation of the Tripetty range. The pe- 
culiar features of the granite are very marked and conspicuous 
in the whole of this western mass of hills, exhibiting itself on 
their slope, in those great bare masses of rock, which are so 
familiar to most people in this country, and on their summits 
in enormous detached rugged piles and fragments. But what 
contributes most powerfully to the interest of this part of the 
route are these singular courses or dykes of trap rocks, which 
may be observed crossing the country, without experiencing 
the smallest deviation or interruption in their course from the 
granitic barriers, which seem to oppose themselves on all hands 
to their progress. 

Their deep black hue, and sharp, well-defined outline, con- 
trasted with the light colour of the granite-masses, through 
and over which they seem to pass, forcibly arrest the attention. 
Granite appears also to a considerable distance on the right 
or north-east side of the road, and probably constitutes the 
greater portion of the very remarkable hill called Naggery Nose, 
as I have traced it nearly to the foot of that hill. The hill just 
mentioned, however, as well as those immediately to the north 
of it, and whose outlines are equally singular, are evidently 
capped with rock of a different nature. 

The caps, which occupy about one-fifth or one-sixth of the 
whole height of the hills, are precipitous and mural on their 
south and east sides, to the north sloping gradually off, until 
they fall almost into the same level with the plains. I at- 
tempted, both from Potoor and Woramullipett, to reach these 
hills, with the view of ascertaining their composition, but the 
distance was too great, and I could only approach their bases. 

Judging from the external appearance of the cap, it is com- 
posed of two distinct rocks arranged in horizontal beds or 
strata. The upper and lower portion of it appeared to be of 
the same nature, being alike in colour, and marked by similar 
numerous, but irregular vertical seams and fissures ; the effect, 
probably, of decomposition. The aspect of the central stra- 
tum or bed, was, however, different from either of those be- 
tween which it lay. It was marked most distinctly through- 
out its whole extent, by regularly parallel and horizontal 
seams, which appeared to be those of stratification ; its colour 
also, which was darker than the others, strengthening the sup- 
position of its being a rock of a different nature*. 

The 

• I have since had an opportunity of examining the hills at Tripetty, 
where both the cap and slope of the hills appeared to consist of but one 

rock. 



of a Route from Madras to Bellary, in 1 822. 359 

The western approach to these hills, for one mile and a 
half or two miles from their bases, was thickly strewed with 
nodules of several varieties of sandstone, the most common of 
which were of rather a close fine grain, sometimes so much so 
as hardly to be distinguished from quartz or hornstone. The 
finer-grained varieties were of different shades of red or brown, 
but generally of a light colour. There was also great abun- 
dance of a very coarse variety, composed of rounded pebbles, 
and fragments of quartz of all sizes, in the same specimen, 
from that of a pin's head to two or three inches in diameter, 
imbedded in a dark green basis. This variety was very re- 
markable. It was composed of rolled fragments and pebbles 
of quartz, which were generally of a white colour in a ground 
of dark green. The cement appears (on the march from 
Naggery to Potoor there were rolled masses of this variety 
twelve to eighteen inches diameter) to be hornblende, which 
communicating its tinge to the finer and transparent particles 
of quartz, affords a beautiful contrast to the large white peb- 
bles imbedded in it. These nodules I should be disposed to 
trace from one or both of the two first-noticed portions of the 
cap, but I met with no fragments of any kind of schistus, owing 
perhaps to my not having approached sufficiently near. It has 
been noticed that the summits of this group of mountains, of 
which Naggery Nose forms the southernmost point, are mural 
and precipitous to the east and south, while to the north they 
fall gradually away, till they nearly coincide with the general 
level of the country. This latter appearance is very striking 
from Curcumbaddy, where the whole of that group is seen in 
reverse ; Curcumbaddy itself being situated at the foot of one 
of these declivities, being a prolongation of the Tripetty 
range, which, from its outline and general aspect, I would infer 
to be of similar structure with that of Naggery. 

The clay-slate, which occupies so great a portion of the 
subsequent route, first makes its appearance at Curcumbaddy; 
but the accumulation of sand and alluvial soil in the Tripetty 
valley, which is crossed on leaving Woramallipett, prevented 
my thus far tracing the continuity of the granite, although it is 
to be observed, with occasional beds of green-stone, in several 
parts of the road. The last rock I recollect to have passed 
before reaching Curcumbaddy was a bed of porphyritic green- 
stone, about one mile and a half or two miles from the village. 

rock, and that sandstone. From this, and other corroborative instances 
on the route between Cuddapah and Ryachootee, I have little doubt that 
the caps of the Naggery range, of the great mass of hills east of that line, 
and, in short, of all the ranges exhibiting the same remarkable outlines, 
consist of varieties of sandstone or conglomerates. 

The 



360 Capt. Cullen's Notice of the Geological Features 

The granites of this division were generally of a light colour, 
shades of white and of a coarse texture ; the darker varieties, 
however, inclining to brown or red, being, I think, the finer 
grained. 

The quartz and felspar were by far the most abundant consti- 
tuents, and gave the colour to the rock ; the hornblende* which 
was of a dark green, being very irregularly and sparingly dis- 
tributed. There seemed to be little or no mica. 

The texture of the trap was very uniform, and of a fine 
grain, composed distinctly of hornblende, and greenish white 
felspar. 

The porphyritic variety, alluded to near Curcumbaddy, 
contained irregular crystals of felspar, of from one-tenth to 
five-tenths of an inch in diameter, of the same colour as the 
felspar of the basis. 

The transition of clay-slate is very sudden and complete. 
The low hills immediately at the back of Curcumbaddy con- 
sist of a compact quartzose sandstone, or hornstone, but the 
clay-slate may be observed in contact with it, within 100 
yards of the north side of the village. From this spot clay- 
slate forms the grand and almost sole constituent; for, with 
the exception of occasional beds of calcareous schistus and 
flinty slate in the valleys and sandstone-caps on some of the 
hills, the great mass of the two singular mountain-chains 
which form the boundary of this interesting valley, on a line 
of upwards of 150 miles, appears to consist entirely of that 
rock. I must add, however, that should an actuarpersonal 
examination of the strata be considered indispensable in sub- 
jects of this nature, these observations must of course, in such 
a case, be considered as only strictly applicable to the high 
road itself, or to a short distance on either hand. 

The seams of stratification are, however, so entirely regular 
and distinct on the slope of the hills on either side, and in 
general so decidedly characteristic of these clay- slate tracts, 
that it is hardly possible to be mistaken in their nature, even 
at a distance of several miles. Towards the commencement, 
the hills are rather thickly clothed with wood ; but on ap- 
proaching Cuddapah, and all to the north of that place, the 
trees are stunted, and but thinly scattered over their sides, 
leaving the strata-seams, like so many artificial terraces or 
ploughed furrows, distinctly exposed to view. The internal 
structure and colour of the slate, in a tract of such extent, 
were of course very various. At Curcumbaddy, and for a 
stage or two afterwards, chiefly shades of red ; about Wunti- 
mettah, purple and gray. Shades of these two last prevailed, 
I think, generally, till within eight miles south of Poonnamilla, 

when 



of a Route from Madras to Bellaiy, in 1 822. 36 1 

when it suddenly altered to green ; and this colour subsequently 
seemed to be constant in all the plains and low grounds. The 
general direction of the strata of clay-slate corresponded with 
that of the ranges of mountains which they composed ; viz. 
about north-north-west and south-south-east, with a very great 
dip to the north-east; all the associated rocks being conform- 
able, unless the sandstone-caps should be an exception, which 
appeared to have a very slight dip, if the appearances noticed 
from Curcumbaddy and Nundialpett may be considered as 
indications of it. However, of the latter I had few favourable 
opportunities for examination. 

The strata of clay-slate appeared sometimes to be nearly 
vertical ; but the exact dip was never measured. 

The same dip and direction of the strata were exhibited in 
the fourth division, of clay-slate. 

Of the rocks associated with clay-slate, the more important 
and general were sandstone, hornstone, calcareous schistus, 
flinty slate, and quartz. Calc-tufa, and marls of infinite variety 
of colour and induration were also found nearly throughout, 
and in some places in extraordinary quantity. 

The sandstone was usually found on the summits of the hills ; 
the calcareous schistus and flinty slate in the valleys; the quartz 
forming veins and layers in the seams of the clay-slate, and 
appearing therefore only where the latter was not concealed 
by alluvial depositions. 

These were sometimes found all together ; but it may be 
more convenient to consider each of them separately. 

The quartz was generally of a white colour, and the layers 
of all degrees of thickness, from one tenth of an inch to one 
foot and a half. It was extremely subject to disintegration, 
covering the ground frequently in such quantity with its no- 
dules, as completely to whiten it. These appearances were 
particularly remarkable on the march from Curcumbaddy to 
Baulpilly, from the vicinity of the hills on both flanks. After- 
wards the valley opens, and the strata are generally concealed 
by the soil ; but whenever rocks appear to any extent, quartz, 
either in veins or layers, will almost invariably be found per- 
vading them. It is very abundant in the clay-slate between 
Nundaloor and Wuntimettah, and here rather remarkable 
from containing numerous little nests of a kind of green earth ; 
until, however, fifty miles north of Cuddapah, and clearing 
the hills beyond Jungumpilly, the individual masses of quartz 
are too inconsiderable in themselves, to serve in any other way 
than merely as a characteristic of the clay-slate, and other 
more important rocks. 

The march from Jungumpilly to Poornamila, with the ex- 
New Series, Vol. 4. No. 23. Nov. 1828. 3 A ception 



362 Capt. Cullen's Notice of the Geological Features 

ceptidn of the first five or six miles, is through an open level 
country, of perhaps fifteen miles square, as if it had been formed 
by the abstraction of a part of the central chain of hills which 
divide the southern and northern portions of this tract into 
two narrow valleys. The Saghilair river is crossed nearly in the 
centre of this open space ; and it is immediately on reaching 
its northern bank that the quartz is observed to assume quite 
a new character, to constitute, as appears subsequently, one 
of the most important features in the remainder of the route. 

A green schistus seems to prevail throughout this plain, and 
it continues as far north as Iddamacul, as may be observed 
from an examination of the wells ; latterly also appearing above 
the surface in ridges of considerable elevation. 

The strata of schistus in the bed of the Saghilair, which are 
nearly vertical, and of a bright green colour, present a very 
interesting appearance. 

The direction of the strata at the ford corresponds with that 
of the bed of the river ; and the stream, which appears subject 
to a very rapid rise and fall, has in consequence worn nu- 
merous deep narrow channels through the slate, presenting 
on all sides sharp perpendicular dykes of fifteen or twenty feet 
high, while they are often but a few inches in thickness. Al- 
most immediately on reaching the north bank of the Saghilair, 
the quartz, which hitherto had never been met with but in 
the seams of the slate, and there seldom exceeding a breadth 
of eighteen inches, is now observed alone in immense blocks, 
and continuous masses, of fifty or sixty feet wide. Their di- 
rection corresponded, I think, generally with that of the strata 
of schistus, but they appeared above the soil unaccompanied 
by any other rock, and forming ridges of such magnitude 
and extent, as to give them the appearance of the summits 
of quartz hills, commencing to be denuded of soil, and forcibly 
impressing one with the idea of being in the vicinity of gra- 
nite: nor was the impression, perhaps, altogether without 
foundation, as the small fort of Iddamacul, twenty miles further 
north, is built on an insulated hill of sienite. 

The quartz ridges became gradually more numerous and 
extensive on my progress up the valley ; but I lost them after 
leaving Iddamacul, and striking off to the westward by Gid- 
deloor towards the Nulla Mulla range. No