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1 



PHILOSOPHICAL 



TRANSACTIONS, 



OF THE 



ROYAL SOCIETY 



or 



LONDON. 



FOR THE YEAR MDCCCV. 



PART I. 



LONDON, 

PRINTED BY W. BULlfER AND CO. GIEVELAND-EOWy 8T. JAHE8*8 ; 
AND SOLD BY G. AND W. NIGOLt PALL-MALL, BOOKSELLERS TO HIS MAJESTTi 

AND PRINTERS TO THE ROYAL SOCIETY. 

MDCCCV. 






» > 



cm 3 



ADVERTISEMENT. 



1 H B ^mmittee appointed by the Rojral Society to direct the pub- 
lication of the Philosopkkal Trunsactionsj take this opportunity to 
acquaint the Public, that it fully appears, as well from the council^ 
books and journals of the Society, as from repeated declarations 
which have been made in several former Transactions^ that the 
printing of them was always, from time to time, the single 9Ct of the 
respective Secretaries^ till the Forty-seventh 'Volume : the Society^ 
as a Body, never interesting themselves any further in their publi- 
.cation, than by occasionally recommending the revival of th^m to 
9ome of their ^^rataries, when, from the particular circumstances 
of their affairs, the Transactions had hskppened for any length of 
time to be intermitted. And this seems principally to have been 
done with a view lo satisfy the Public, that their usual meetings were 
then continued, for the improvement of knowledge, and benefit of 
mankind, the great ends of their first institution by the Royal. 
Charters, and which they have ever since steadily pursuedL 

But the Society being of late years greatly enlarged, and their 
communications more numerous, it was thought advisable, that a 
Committee of their members should be appointed, to reconsider the 
papers read before them, and select out of them such as they should 
judge most proper for publication in the future Transactions; which 
was accordingly done upon the 26th of March, 1752. And the 
grounds of their choice are, and will continue to be, the importance 
and singularity of the subjects, or the advantageous manner of 

Aft 



Civ 3 

treating them ; without pretending to answer for the certainty of the 
facts, or propriety of the reasonings, contained in the several papers 
so published, which must still rest on the credit or judgment of 
their respective authors. 

It is likewise necessary on this occasion to remark, that it is an 
established rule of ihe Society, to which they will always adhere, 
never to give their opinion, as a Body, upon any subject, either of 
Nature or Art, that comes before them. And therefore the thankf 
which are frequently proposed frotn ^he Chair, to be given' to the 
authors of such papers as are read at their accustomed meMihgs, or' 
to the persons through whose hands they receive them, are to be 
considered in no other light ihzn as a matter ot civility,' in return 
for the respect shewn, to the Sbcicty by those communications. The 
ltbeialsa:is!to bersiid with regard to the ^everSil ptojtcis, ihvehiion^ 
and -curiosities ofJvarious kinds, which^are' often en^hi^ited to.thfe 
Society ; ihe authbrs thereof, or thoset who exhibit theni, frequently 
take the liberty to report^ and even to certify in the j^ublic'news'- 
papers, ihat theyhave met with' the highest applause andappro*^ 
batio^u Andth^efore it is'hoped, thatnd f^^rd will hidreaftet- be 
f>aud to such reports and public notices ; which in some instance! 
have been too lightly credited, to the dishonour of the Society/' 






< .' 



,. . \ 



CONTENTS. 



!• I HE Croonian Lecture on muscular Motion. By Anthony 
Carlisle, jE^^. F.R^S.^ page i 

II. Experiments for asc^aining how far Telescopes will enable ut 
to determine very small Angles^ and to distinguish the real from 
the spurious Diameters of celestial and terrestrial Objects : with 
an Application of the Result of these Experiments to a Series of 
Observations on the Nature and Magnitude of Mr. Harding's 
lately discovered Star. By William Herschel, LL. D. F. R. S. 

P-31 

III. An Essay on the Cohesion of Fluids. By Thomas Young, 

M. D. For. Sec. R.S. p. 71 

IV. Concerning the State in which the true Sap of Trees is depo-- 
sited during Winter. In a Letter from Thomas Andrew 
Knight, E^q. to the Right Hon. Sir Joseph Banks, Bart. K. B. 
P.R.S. p. 88 

V. On the Action of Platina and Mercury upon each other. By 
Richard Chenevix, Esq. F. R. S. M. R. L A. &c. p. 104 

VI. An Investigation of all the Changes of the variable Star in 
Sobieski's Shield, from five Teafs Observations, exhibiting its 
proportional illuminated Parts, and its Irregularities of Rota- 
tion ; with Conjectures respecting unenlightened heavenly Bodies. 
By Edward Pigott, Esq. In a Letter to the Right Hon. Sir 
Joseph Banks, K. B. P.R.S. P- 131 



VII. An Account af seme analytical Experiments on a mineral 
Production from Devonshire ^ consisting principally of Alumine 
and Water. By Humphry Davy, Esq. R R. S. Professor of 
Chemistry in the Royal Institution. page 155 

VIII. Experiments on FTootz. By Mr.- David Mushet. " Com^ 
municated by the Right Hon. Sir Joseph Banks, K. JB. P. R. S^ 

p. 163 

APPENDIX. 

Meteorological Journal kept at the Apartments of the Royal 
Society, by Order of the President and Council. 



ERRATA. 



Page 4. line 5 from the hotxomy for acdpenser, rtttd acipenseiv 
11. — 20 f for their, read its. 
26. — 7, read 6 ounces of water. 
76w — last but one,ybr ,0054, read J>54f.. 



The President and Council of the Royal Society adjudged, 
for the Year I804, the Medal on Sir Godfrey Copley's Donation, 
to Smithson Tennant, Esq. F. R. S. for his various Chemical 
Discoveries, communicated to the Society, and printed in several 
Volumes of the Transactions* 

And they adjudged the Gold and Silver Medals, on the Donation 
of Benjamin Count of Rumford, to Mr. John Leslie of Largo, 
for his Experiments on Heat, published in his Work, entitled an 
Experimental Inquiry into the Nature and Propagation of Heat. 



PHILOSOPHICAL 



TRANSACTIONS 



!• The Croonian Lecture on muscular Motion. By Anthony 

Carlisle, Esq. F. R. S. 



{lead November 8, 1804. 

Aj^imal irfiysiology has derived several illustrations and 
additions, from the institution of this Lecture on muscular 
Motion ; and the details of anatomical knowledge have been 
considerably augmented by descriptions of muscular parts 
before unknown. 

Still, however, many of the phenomena of muscles remain 
unexplained, nor is it to be expected that any sudden insulated 
discovery shall solve such a variety of complicated appearances. 

Muscular motion is the first sensible operation of animal 
life : the various combinations of it sustain and carry on the 
multiplied functions of the largest animals : the temporary 
cessation of this motive faculty is the suspension of the living 
powers, its total quiescence is death. 

By the continuance of patient, well directed researches, it is 
reasonable to expect much important evidence on this subject ; 

MDCCCV. B 



2 Air. Carlisle's Lecture 

and, from the improved state of collateral branches of know- 
ledge, together with the addition of new sources, and methods 
of investigation, it may not be unreasonable to hope for an 
ultimate solution of these phenomena, no less complete, 
and consistent, than that of any other desideratum in physical 
science. 

The present attempt to forward such designs is limited to 
circumstances which are connected with muscular motion, con- 
sidered as causes, or rather as a series of events, all of which 
contribute,^ more or less, as conveniences, or essential requi- 
sites, to the phenomena ; the details of muscular applications 
being distinct from the objects of this lecture. 

No satisfactory explanation has yet been given of the state 
or changes which obtain in muscles during their contractions 
or relaxations, neither are their corresponding connections 
with the vascular, respiratory, and nervous systems, suffidently 
traced. These subjects are therefore open for the present en- 
quiry, and although I may totally fail in this attempt to elu- 
cidate any one of the subjects proposed, nevertheless I shall 
not esteem my labour useless, or the time of the Royal Society 
altogether unprofitably consumed, if I succeed in pointing out 
the way to the future attainment of knowledge so deeply 
interesting to mankind. 

The muscular parts of animals are most frequently com- 
posed of many substances, in addition to those which are purely 
muscular. In this gross state, they constitute a flexible, com- 
pressible solid, whose texture is generally fibrous, the fibres 
being compacted into fasciculi, or bundles of various thickness. 
These fibres are elastic during the contracted state of muscles 
after death, being capable of extension to more than one-fifth 



on muscular Motion^, 3 

of their length, and of returning again to their former state of 
contraction. 

This elasticity, however, appears to belong to the enveloping 
reticular or cellular membrane, and it may be safely assumed 
that the intrinsic matter of muscle is not elastic. 

The attraction of cohesion, in the parts of muscle, is strongest 
in the direction of the fibres, it being double that of the con- 
trary, or transverse direction. . 

When muscles are capable of reiterated contractions and 
relaxations, titiey are said to be alive^ or to possess irritability. 
This quality fits the organ for its functions. Irritability will be 
considered, throughout the present lecture, as a quality only. 

When muscles have ceased to be irritable, their cohesive 
attraction in the direction of their fibres is diminished, but it 
remains unaltered in the transverse direction. 

The hinder limbs of a frog attached to the pelvis being 
stripped of the skin, one of them was immersed in water at 
US'" oi Fahrenheit, during two minutes, when it ceased to 
be irritable. The thigh bones were broken in the middle, 
without injuring the muscles, and a scale affixed to the ancle 
of each limb : a tape passed between the thighs was employed 
to suspend the apparatus. Weights were gradually introduced 
into each scale, until, with five pounds avoirdupois, the dead 
thigh was ruptured across the fleshy bellies of its muscles. 

The irritable thigh sustained six pounds weight avoirdupois, 
and was ruptured in jhe same manner. This experiment was 
repeated on other frogs, where one limb had been killed by a 
watery solution of opium, and on another where essential oil 
of cherry laurel * was employed : in each experiment, the 

• Distilled oil from the leaves of the Prunus Lauro-cerasus. 

B 2 



4 Mr. Carlisle's Lecture 

irritable limb sustained a weight one-sixth heavier than the 
dead limb. 

It may be remarked, in confirmation of these experiments, 
that when muscles act more powerfully, or more rapidly, than 
is equal to the strength of the sustaining parts, they do not 
usually rupture their fleshy fibffes, but break their tendons, or 
even an intervening bone, as in the instances of ruptured tendo 
Achillis, and fractured patella. Instances have however oc- 
curred, wherein the fleshy bellies of muscles have been 
lacerated by spasmodic actions ; as in tetanus the recti abdo- 
minis have been torn asunder, and the gastrocnemii in cramps ; 
but in those examples it seems that either the antagonists pro- 
duce the effect, or the over-excited parts tear the less excited 
in the same muscle. From whence it may be inferred, that the 
attraction of cohesion in the matter of muscle is considerably 
greater during the act of contracting, than during the passive 
state of tone, or irritable quiescence, a fact which has been 
always assumed by anatomists from the determinate forces 
which muscles exert. 

The muscular parts of diflferent classes of animals vary in 
colour and texture, and not unfrequently those variations occur 
in the same individual. 

The muscles of fishes and vermes are often colourless, 
those of the mammalia and birds being always red : the am- 
phibia, the acdpenser, and squalus genera, have frequently 
both red and colourless muscles in the same animal. 

Some birds, as the black game,* have the external pectoral 
muscles of a deep red colour, whilst the internal are pale. 

In texture, the fasciculi vary in thickness, and the retiailar 

• Tetrao Utrix. Lin. 



Qfi muscidar Motion. Ji 

membrane is in some parts coarse^ and in others delicate : the 
heart is * always compacted together by a delicate reticular 
membrane, and the external glutsei by a coarser species. 

An example of the. origin of muscle is presented in the 
history of the incubated egg^ but whether the rudiments bf 
the punctum saliens be part of the cicatricula organised by the 
parent) or a structure resulting from the first process of incu- 
bation, may be doubtful : the little evidence to be obtained on 
this point seems. in favour of the former opinion ; a regular 
confirmation of which wottjd improve the knowledge of animal 
generation by shewing that it is gemmiferous. There are suf- 
ficient analogies of this kind in nature, if reasoning from 
analogies were proper for the ^preseAt occiiision. 

The pimctuiti saliens, during its first aOticms^ is not encom- 
passed by any fibres discoverable wth microscopes, and the 
vascukr system is not then evolved, .thd blood fldwing for- 
wards, and backwards, m the same vessels. The commence- 
tnent of life in artiraal^ of complex structure Isj from the 
preceding fact, like the ultiitiate organization of the simpler 
classes. 

It is obvious that the muscles of birds are formed out of the 
albumen ovi, the vitellus, and the atmospheric air, acted upon 
by a certain teitiperature. The albumen of a bird's egg is 
wholly consumed during incubation, and the vitellus little di^ 
minished, proving that the albumen contains the principal 
elementary materials of the animal thus generated ; and it 
follows that the muscular parts, which constitute the greater 
proportion of such animals when hatched, are made out of the 
albumen, a small portion of the vitellus, and certain elements^ 
or small quantities of the whole compound of the atmosphere. 



6 Mr. Carlisle's Lecture 

The muscles of birds ar6 not different, in any respect, fr&iti' 
those of quadrupeds of the class of mammalia. 

The anatomical structure of muscular fibres is generally 
complex, as those fibres are connected with membrane, blood- 
vessels, nerves, and lymphaeducts.; which seem to be only 
appendages of convenience to the ess.ential matter of muscle. 

A muscular fibre, duly prepared by washing away the ad- 
hering extraneous substances, and ex|)0sed to view in a powerful 
microscope, is undoubtedly a solid cylinder, the covering of 
which is reticular membrane, and the contained part a pulpy 
substance irregularly granulated, and of little cohesive power 
when dead. 

A difficulty has often subsisted among anatomists concerning 
the ultimate fibres of muscles; and, because of their tenuity, 
some persons have considered them infinitely divisible, a 
position which may be contradicted at any time, by an hour's 
labour at the microscope. 

The arteries arboresce copiously upon the reticular coiat of 
the muscular fibre, and in warm-blooded animals these vessels 
are of sufficient capacity to admit the red particles of blood, 
but the intrinsic matter of muscle, contained within the ultimate 
cylinder, has no red particles. 

The arteries of muscles anastomose with corresponding 
veins ; but this course of a continuous canal cannot be sup- 
posed to act in a direct manner upon the matter of muscle. 

The capillary arteries terminating in the muscular fibre 
must alone effect all the changes of increase in the bulk, or 
number, of fibres, in the replenishment of exhausted materials^ 
and in the repair of injuries ; some of these necessities may be 
supposed to be continually operating. It is well known, that 



' on muscular Motion. 7 

^e circulation of the blood is not essential to muscular action ; 
.so that the mode of distribution of the blood vessels, and the 
differences in their size, or number, as applied to muscles, can 
only be adaptations to some special convenience. 

Another prevalent opinion among anatomists, is the infinite 
extension of vascularity, which is contradicted in a direct 
manner by comparative researches. The several parts of a 
quadruped are sensibly more or less vascular, and of different 
contextures ; and, admitting that the varied diameter of the 
blood vessels disposed in each species of substance, were to be 
constituted by the gross sensible differences of their larger 
vessels only, yet, if the ultimate vessels were in all cases 
equally numerous, then the sole remaining cause of dissimi- 
larity would be in the compacting of the vessels. The vasa 
vasorum of the larger trunks. furnish no reason, excepting that 
of a loose analogy, for the supposition of vasa vasorum ex- 
tended without limits. Moreover, the circulating fluids of all 
animals are composed pf water, which gives them fluidity, and 
of animalised particles of defined configuration and bulk; it 
follows that the vessels through which such fluids are to pass^ 
muist be of wifficient capacity for the size of the particles, and 
that smaller vessels could only filtrate water devoid of such 
animal particles: a position repugnant to all the known facts 
of the circulation of blood, and the animal economy. 
. The capillary art^rjes. which terminate in the muscular fibre^ 
must be secretory vessels for depositing the muscular matter, 
thelympheeducts serving to remove the superfluous extravasated 
watery fluids, and the decayed substances which are unfit 
for use. 

The lymphasducts are not so numerous as the blood vessels^ 



9 Mr. Carlisle's Lecture 

diid certainly, do not eifX^id to every muscular fiH^e: they 
appear to receive theif contained fluids from the intersticial 
spaces formed by the reticular or cellular membrane^ an<i 
not from the projecting open ends of tubes^ as is generaUy 
represented. This mode of receiving Snids pitf of a ^UuJar 
structure, and conveying them into cylindrical vessels, is ex- 
emplified in the corpora cavernosa, and corpus spongiosum 
penis, where arterial blood is poured into cellular or reticular 
cavities, and from thence it passes into conunon veins by tjbe 
gradual coarctation of the cellular canals. 

In the common green turtle, the lacteal vessels universally 
arise from the loose cellular membrane, situated between the 
internal spongy coat of the intestines and the muscular co9t. 
The cellular structure may be filled from the lacteals, or the 
lacteals from the cellular cavities. When injecting the smaller 
branches of the lymphasducts retrograde in an oedematous 
human leg, I saw, very distinctly, three orifices of these vessels 
terminating in the angles of the cells, into which the quick-^ 
silver tridded. The preparation is preserved, and; a drawing of 
the appearance made at the time. It was also proved, by many 
experiments, that neither the lympha^ducts, nor the veins, 
have any valves in their minute branches. 

T^e nerves of vohmtary muscles separate from the same 
bundles of fibrils with the nerves which are distributed in the 
skin, and other parts, for sensation ; but a gre^tw proportion 
of nerve is appropriated to the voluntary muscles, than to any 
other substances, the organs of the senses excepted. 

The nerves of volition all arise from the parts formed by 
the junction of the two great masses of the brain, called the 
Cerebrum and Cerebellum, and from the extension of that 



on muscular Motion . 9 

substance throughout the canal of' the vertebrae. Another 
class of muscles, which are hot subject to the will, are supplied 
by peculiar nerves ; they are much smaller, in proportion to 
the bulk of the parts on which they are distributed, l^an those 
of the voluntary muscles ; . they contain less of the white 
opaque medullary substance than the other nerves, and unite 
their fibrils, forming numerous anastomoses with all the other 
nerves of the body, excepting those appropriated to the organs 
of the senses. There are enlargements at several of these 
junctions, called Ganglions, and which'are composed of a less 
proportion of the medullary substance, and their texture is 
firmer than that of ordinary nerves. 

The terminal extremities! of nerves have been usually con^ 
sidered of unlimited extension; by accurate dissecticm how^ 
ever, and the aid of magnifying glasses; the extreme fibrils of 
nerves are easily traced as far as their sensible properties; and 
their continuity extends. The fibrils cease to be isaibdivided 
whilst perfectly visible to the naked ieye, in the voluntiiry 
muscles of large animals, and the spaces they occupy upon 
superfides where they seem to end, leave a remarkable excess 
of parts unoccujHed by those fibrils. The extreme fibrils of 
nerves lose their opacity, the medullary substance appears soft 
and transparent, the enveloping membrane becomes pellucid, 
and the whole fibril is destitute of the tenacity necessary to 
preserve its own distinctness; it seems to be diffiised and 
mingled with, the substances in which it ends. Thus thie ulti- 
mate tenmnatioAs of nerves for volition, and ordinary sensiation^ 
appear to be in the reticular membrane, the common covering 
of all the different substances in an animal body, and the ccm-^ 
necting medium of all dissimilar parts. 



10 Mr. Caw-isle's Lecture 

By this skn|>le disposition, the medullary suhstance of nerve 
is spread through all oi^anized, sensible, or motive parts^ 
forming a continuity which is probably the occasion of sym- 
patiiy. Peculiar nerves^ su^h as tl;^ first and second pairs, and 
^e ipordo mollis of the sev^nlii, terminate in an expanse of 
medullary, substance which tx>mfaines with, other parts and 
membranes, still keeping the sensible excess of the peculiar 
medullary matter. 

The peculiar substance of nerves must in time become inef^ 
iident ; and, a3 it is liable to injuries, the powers of restoration^ 
and repair, are Extended to that material. The reunion of 
nerves after their division, and the, reproduction after part of a 
nerve has been cut away, have been established by decisive 
experiments. Whether th^e is any new medullary substance 
employed to fill up the br^k, and, if so, whether the. new 
fiubst«hce foe generated at the part^ or pn>truded along, the 
nervous theca from the brain, ai^e points, undetiennined : the 
history of the formation of a foettid, the stru^^ture of certain 
mcnsters, and the orgamzadoti of simple, anin^als, all seem, to 
favour the probability, that the medullary matter of nerves is 
formed at the parts where it is required^ and not in the pipisk^ 
dpal/seat of the Cerebr^L medulla. 

This doctrine, dearly established, would. lead to. the belief 
of a v&ry extended commixture of this peculiar matter in ail 
tibe sensible and irritable parts of animals, leaving the nerves 
in their limited distribution^ die simple office of cohveyii^, im* 
pressions from the two sentient masses with wliioh their 
extremities are connected. The most ssnple aramals m whoQi 
no visible appearances of brain or fierves are to be fouind, and 
no fibrous arrangement of anusdes/ may ibe.considevedof this 



,^ . 



' on muscular Mbtion. li 

deScfiptidti : Mi-. JoflN Hunter appeared to have had some 
iftcomplete ftrotidiis u'po^ thisf subject, which may be gathered 
from hisf represe*itatfc>n! of a materik vitse in his Treatise on the 
htodd, &i. Perhaps it WouM h^ more proper to distinguish 
the |)i6fculiar mattei' of mYisele by some specific term, siich, for 
example. As h^ateria cbntractiRs. 

A particular adaptation for the nerves which supply the 
electi^ical batteries of the torpedo, and gymnotus, is observable, 
on the exit of each from' the slcuU ; over which there is a firm 
cartilage acting as a yoke, with a muscle affixed to it, for the 
obvious purpose of compression : so that a voluntary muscle 
probably governs the operations of the battery. 

■ • 

The matter of the nerves, ihd brain, iis very similar in all 
die diiflferent classes of animals. 

The ejttemdl cohfiguratioh of ailimals is not ihore varied 
than theii* interrial structilre. 

Th« bulk of sai ahihiki, the lihtitatlbii of its existence, the 
medium in whidh it Bvfes, and the' habits it is destined to 
pursue, are each, ind ill of therti, so miny indications of the 
complexity or samplicity of theit ihterhal structure. It is 

» 

notorious that the number of organs, and 6f*members,is varied 
in all the different classes of animals ; the vascular and nervous 
systfems, thet respiriatory , and digestive organs, the parts for 
procreation, and the iristnimerits of motion, are severally varied, 
arid adapts to the cbriditioh of the species. This modification 
of anatomical stru6ture is extended in the lowest tribes of ani- 
mals, until the body appears to be oiie homogeneous substance. 
The cavity for deceiving the food is indifferently the internal, 
or external surface, for they may be inverted, and still con- 
tinue to digest food; the limbs or tentlacula maybe cut ofif^ 



i« Mr. Carlisle's Lecture 

and they will be regenerated without apparent inconvenience 
to the individual : the whole animal is equally sensible^ equally 
irritable, equally alive : its procreation is gemmiferous. Every 
part is pervaded by the nutritious juices, every part is acted 
upon by the respiratory influence, every part is equally capable 
of motion, and of altering its figure in all directions, whilst 
neither blood-vessels, nerves, nor muscular fibres, are disco- 
verable by any of the modes of investigation hitherto instituted. 

From this abstract animal ( if such a term may be admitted ) 
up to the human frame, the variety of accessory parts, and of 
organs by which a complicated machinery is operated, exhibit 
infinite marks of design, and of accommodations to the pur- 
poses which fix the order of nature. 

In the more complicated animals, there are parts adapted 
for trivial conveniences, much of their materials not being 
alive, and the entire offices of some liable to be dispensed 
with. The water transfused throughout the intersticial spaces 
of the animal fabric, the combinations with lime in bones, 
shells, and teeth ; the horns, hoofs, spines, hairs, feathers, and 
cuticular coverings, are all of them, or the principal parts of 
their substance, extra-vascular, insensible, and unalterable by 
the animal functions after. they are completed. I have formed 
an opinion, grounded on extensive observation, that many 
more parts of animal bodies may be considered as inanimate 
substances ; even the reticular membrane itself seems to be of 
this class, and tendons, which may be the condensed state of 
it; but these particulars are foreign to the present occasion. 

The deduction now to be made, and applied to the history 
of muscular motion, is, that animated matter may be connected 
with inanimate ; this is exemplified in the adhesions of the 



on muscular Motion. 13 

muscles of multi-valve, and bi-valve shell fish, to the inorganic 
shell, the cancer Bemhardus to the dead shells of other ani- 
mals, and in the transplantation of teeth. All of which, although 
isomewhat contrary to received opinion, have certainly no 
degree of vascularity, or vital connection with the inhabitant ; 
these shells being liable to transudations of cupreous salts and 
other poisonous substances, whilst the animal remains unin- 
jured. A variety of proofs to the same effect might be adduced, 
but it would be disrespectful to this learned Body to urge any 
farther illustrations on a subject so obvious. 

The effects of subdivision, or comminution of parts among 
the complicated organized bodies, is unlike that of mineral 
bodies : in the latter instance, the entire properties of the sub- 
stance are retained, however extensive the subdivision ; in the 
former substances, the comminution of parts destroys the 
essential texture and composition, by separating the gross 
arrangements of structure upon which their specific properties 
depend. From similar causes it seems to arise, that animals of 
minute bulk are necessarily of simple structure : size alone is 
not, however, the sole cause of their simple organization, be- 
cause examples are sufficiently numerous wherein the animal 
attains considerable bulk, and is of simple structure, and vice 
versa : but, in the former, the medium in which they live, and 
the habits they assume, are such as do not require extensive 
appendages, whilst the smaller complex animals are destined 
to more difficult, and more active exertions. It may be as- 
sumed however, as an invariable position, that the minutest 
animals are all of simple organization. 

Upon a small scale, life may be carried on with simple ma- 
terials ; but the management, and provisions for bulky ammal$> 



14 Mr. Carlisle's Lecture 

with numerous limbs, and variety of organs, and appendages 
of convenience, are not effected by simple apparatus ; thus, the 
skeleton whidi gives a determinate figure to the species, sup- 
ports its SG£t parts, and admits of a geometrical motion, is 
placed interiorly, where the bulk of the animal admits of the 
bones being sufficiently strcmg, and yet light enough for the 
moving powers ; but the skeleton is placed externally, where 
the body is reduced below a certain magnitude, or where the 
movements of the animal are not to be of the floa?ting kind : in 
which last case the bulk is not an absolute cause. The examjdes 
of testaceous vermes, and coleopterous, as well a& most other 
insects, are universally known. 

The opinion of the muscularity of the crystalline lens of the 
eye, so ingeniously urged by a learned member of this Society, 
is probably well founded; as the arrangement of radiating 
lines of the matter of muscle, from the centre to the circum^ 
ference of the lens , and these compacted into angular masses, 
would produce specific alterations in its figure. 

This rapid sketch of the history of muscular structure has 
been obtruded before the Royal Society to introduce the prin- 
cipal experiments, and reasonings which are to follow : they 
are not ordered with so much exactness as becomes a more 
deliberate essay, but the intention already stated, and the limits 
of a lecture are offered as the apology. 

Temperature has an essential influence over the actions of 
imuscles^ but it is not necessary that the same temperature 
should subsist in all muscles during their actions ; neither is it 
essential that all the muscular parts of the same animal should 
be of uniform temperatures for the due performance of the 
motive functions. 



on muscular Motion. 1 5 

It appears that all the classes of animals are endowed with 
some power of producing thermometrical . heat, since it has 
been so established in the amphibia, pisces, vermes, and insecta, 
by Mr. John Hunter ; a fact which has been verified to my 
own experience ; the term " cold-blooded'* is therefore only 
relative. The ratio of this power is not, however, in these 
examples, sufficient to preserve their equable temperature in 
cold climates, so that they yield to the changes of the at- 
mosphere, or the medium in which they reside, and most of 
them become torpid, approaching to the degree of freezing 
water. Even the mammalia, and aves, possess only a power 
of resisting certain limited degrees of cold ; and their surfaces, 
as well as their limbs, being distant from the heart, and prin- 
cipal blood-vessels, the muscular parts so situated are subject 
to considerable variations in their temperature, the influence of 
which is known. 

In those classes of animals which have Dttle power of gene- 
rating heat, there are remarkable diflferences in the structure 
of their lungs, and in the composition of their blood, from the 
mammalia and aves. 

Respiration is one of the known causes which. influences the 
temperatures of animals : where these organs are extensive, 
the respirations are performed at Tegular intervals, and are not 
governed by the will, the whole mass of blood being exposed 
to the atmosphere in each circulation. In all such animals 
' living without the tropics, thdr temperature ranges above the 
ordinary heat of the atmosphere, their blood contains more of 
the red particles than in the other classes, and their muscular 
irritabilhy ceases more rajsdly after violent death. 

The respirations of the animals denominated ^f cold-blooded," 



16 Mr. Carlisle's Lecture 

are effected differently from those of high temperature ; in 
some of them, as the amphibia of LiNNiEus, the lungs receive 
atmospheric air, which is arbitrarily retained in large cells, and 
not alternately, and frequently changed. The fishes, and the 
testaceous vermes, have lungs which expose their blood to 
water, but whether the water alone, or the atmospheric air 
mingled with it, furnish the changes in the pulmonary blood, 
is not known. 

In most of the genera of insects, the lungs are arborescent 
tubes containing air, which, by these channels, is carried to 
every vascular part of the body. Some of the vermes of the 
simpler construction have no appearance of distinct organs, but 
the respiratory influence is nevertheless essential to their ex- 
istence, and it seems to be effected on the surface of the whole 
body. 

In all the colder animals, the blood contains a smaller pro- 
portion of, the red colouring particles than in the mammalia, 
and aves ; the red blood is limited to certain portions of the 
body, and many animals have none of the red particles. 

The following animals were put into separate glass vessels, 
each filled with ^ pound weight of distilled water, previously 
boiled to expel the air, and the vessels inverted into quicksilver; 
viz. one gold fish, one frog, two leeches, and one fresh-water 
muscle.* These animals were confined for several days, and 
exposed to the sun in the day time, during the month of 
January, the temperature being from 43"" to 48"", but no air 
bubbles were produced in the vessels, nor any sensible dimi- 
nution of the water. The frog died on the third day, the fish 
on the fifth, the leeches on the eighth, and the fresh-water 

• Myiilui AtuiUnus. 



on muscular Motion, vj 

m 

muscle on the thirteenth. This unsuccessful experiment was 
made with the hope of ascertaining the changes produced in 
Water by the respiration of aquatic animals, but the water had 
not undergone any chemical alteration. 

Animals of the class mammalia which hybernate, and become 
torpid in the winter, have at all times a power of subsisting 
under a confined respiration, which would destroy other ani- 
mals not having this peculiar habit. In all the hybemating 
mammalia there is a peculiar structure of the heart, and its 
principal veins ; the superior cava divides irfto two trunks ; the 
left, passing over the left auricle of the heart, opens into the 
inferior part of the right auricle, near to the entrance of 
the vena cava inferior. The veins usually called azygos, 
accumulate into two trunks, which open each into the branch 
of the vena cava superior, on its own side of the thorax. The 
intercostal arteries and veins in these animals are unusually 
large. 

This tribe of quadrupeds have the habit of rolling up their 
l^pdies into the form of a ball during ordinary sleep, and they 
invariably assume the same attitude when in the torpid state : 
the limbs are all folded into the hollow made by the bending 
of the body ; the clavicles, or first ribs, and the sternum, are 
pressed against the fore part of the neck, so as to interrupt the 
flow of bldod which supplies the head, and to compress the 
trachea: the abdominal viscera, and the hinder limbs are 
pushed against the diaphragm, so as to interrupt its motions, 
and to impede the flow of blood through the large vessels 
which penetrate it, and the longitudinal extension of the cavity 
of the thorax is entirely obstructed. Thus a confined drcu^ 
lation of the blood is carried on through the heart, probably 

MDCCCV. D 



i8 iVfr. Carlisle's Lecture 

adapted to the last weak actions of life, and to its gradual 
recommencement. 

This diminished respiration is the first step into the state of 
torpidity ; a deep sleep accompanies it ; respiration then ceases 
altogether ; the animal temperature i& totally destroyed, cold- 
ness and insensibility take place, and finally the heart concludes 
its motions, and the muscles cease to be irritable. It is worthy 
of remark that a confined air, and a confined respiration, ever 
precede these phenomena : the animal retires from the open 
atmosphere,, his mouth and nostrils are brought into contact 
with his chest, and enveloped in fur ; the limbs become rigid, 
but the blood never coagulates during the dormant state. On 
being roused, the animal yawns, the respirations are fluttering^ 
the heart acts slowly and irregularly, he begins to stretch out 
his limbs, and proceeds in quest of food. During this dor- 
mancy, the animal may be frozen, without the destruction of 
the muscular irritability, and this always happens to the gardeit 
<snail,* and to the chrysalides of many insects during the winter 
of this climate. 

The loss of motion and sensation from the influence of low 
temperature, accompany each other, and the capillaries of 
the vascular system appear to become contracted by the loss 
of ammal heat, as in the examples of numbness from cold. 
Whether the cessation of muscular action be owing to the 
Impeded influence of the nerves^ or to the lowered temperature 
of the muscles themselves, is doubtful ; but the known iib 
fluence of cold upon the sensorial system, rather favours the 
supposition that a certain temperature is necessary for the 
transmission of nervous influence, as well as sensation.. 



on muscular Motion . 1 9 

The hybernating animals require a longer time in drowning 
than others. A full grown hedge-hog was submersed in water 
at 48"*, and firmly retained there ; air-bubbles began instantly 
to ascend, and continued during four minutes ; the anittial was' 
not yet anxious for its liberty. After seven minutes it began 
to look about, attempting to escape ; at ten minutes it rolled 
itself up, only protruding the snout, which was hastily re- 
tracted on being touched with the finger. And even the approach 
of the finger caused it to retract. After fifteen minutes com-^' 
plete submersion, the animal still remained rolled up^ and 
withdrew its nose on being touched. After remaining thirty 
minutes under water, the animal was laid upon flannel, in an 
atmosphere of 6s'', with its head inclined downwards ; it soon- 
began to relax the sphincter muscle which contracts the skin, 
slow respirations commenced, and it recovered entirely ,without 
artificial aid, after two hours. Another hedge-hog submersed 
in water at 94*, remained quiet until after five minutes ; about 
the eighth minute it stretched itself out, and expired at the 
tenth. It remained relaxed, and extended, after the cessation 
of the vital functions ; and its muscles were relaxed, contrary 
to those of the animal drowned in the colder water. 

The irritability of the heart is inseparably connected with 
respiration. Whenever the inhaled gas differs in its properties 
from the common atmosphere, the muscular and sensible parts 
of the syistem exhibit the change : the actions of the heart are 
altered or suspended, and the whole muscular and sensorial 
systems partake of the disorder : the temperature of animals, 
as before intimated, seems altogether dependant on the respi- 
ratory functions, although it still remains uncertain in what 
manner this is effected. 

Da 



«o- Mr. Carlisle's Lecture 

The blood appears to be the medium of conveying heat to 
the difierent parts of the body ; and the changes of animal 
temperature in the same individual at various times, or in its 
several parts, are always connected with the degree of rapidity 
of the circulation. It iS no very wide stretch of physiological 
deduction to infer, that this increased temperature is ^oduced 
by the more frequent expostnre of the mass of blood to the 
respiratory infiuenoe, and the short time allowed in each circuit 
ibr the loss of the acquired heat. 

The blood of an animal is usually coagulated immediately 
after death, and the muscles are contracted ; but, in some pe* 
culiar modes of death, neither the one, nor the other of these 
effects are produced : with such exceptions, the two phenomena 
are concomitant. 

A preternatural increase of animal heat delays the coagu-* 
lation of the blood, and the last contractions of the muscles : 
'these contractions gradually disappear, before any changes 
from putrefaction are manifested ; but the cup in the coagulum 
of blood does not relax in the same manner ; hence it may be 
inferred, that the final contraction of muscles is not the coagu* 
lation of the blood contained in them ; neither is it a change in 
the reticular membrane, nor in the blood-vessels, because such 
contractions are not general throughout those substances. The 
coagulation of the blood is a certain criterion of death. The 
reiterated visitations of blood are not essential to muscular 
irritability, because the limbs of animals, separated from the 
body, continue for a long time afterwards capable of contract 
tions, and relaxations. 

The constituent elementary materials of which the peculiar 
animal and v^etable substances consist, are not separable hy. 



M fnuscuUff' Motion. " »t 

any chemical processes hitherto instituted, in such manner as 
to allow of a reoomtMnation into their former state. The com* 
position of these substances appears to be naturally of transient 
duration, and the attractions of the elementary materials which 
form the gross substances, are so loose and unsettled, that 
they are all decomposed without the intervention of any agents 
merely by the operation of their own elementary parts on each 
other. 

An extensive discussion of the diemical properties attaching 
to the matter of muscle would be a labour unsuited to this 
occasion ; I should not, however, discharge my present duty,, 
if I ixnitted to say, that all sudi investigations can only be 
profitable when effected by simple processes, and when made 
upon the raw materials of the animal fabric, §uch, perhaps, as 
the albumen of eggs, and the blood. But, until by synthetical 
experiments the peculiar substances of animals are composed 
from what are considered to be elementary materials, or the 
changes of organic Secretion imitated l^ art, it cannot be hoped 
that any determinate knowledge should be established upom 
which the physiology of muscles may be explained. Such 
researches and investigations promise, however, the most pro- 
bable ultimate success, since the phenomena are nearest allied 
to those of chemistry, and since all other hypotheses have, in 
their turns, proved unsatisfactory. 

Facts and Experiments tending to support and tlhstrate the pre^ 

ceding Arguments 

An emaciated horse was killed hy divicfing the medulla spinalis^ 
and the large blood-vessels under the first bone of the sternum* 



TI4 M-. CaklisIe's Lecture 

The temperature of the flowing blood was 103* 

Spleen • - 103 
Stomach - - ioi . 
Colon - - 98 
. Bladder of urine 97 
Atmosphere - 30. 
Three pigs, killed by a blow on the head, ^d by the imme- 
diate division of the large arteries and veins, entering the n>iddla 
of the basis of the; heart, had the blood flowing from these 
vessels of 106, 106^, and 107* ; the atmospheric temperature 
being at 31^ 

An ox, killed in a similar manner, the blood 103°; atmo- 
sphere 50^ > 

Three sheep, killed by dividing the. carotid articries^ and in- 
temal jugular veins: theirblood 105, 105, 105^"*; atmosphere 41*. 
Three frogs, kept for many days in an equable atmosphere 
at 54"* ; their stomachs 62''. 

' The watery fliiid issuing from a person tapped for dropsy 
of the belly loi**: the atmosphere being 43°, and the tem- 
perature of the superficies of the body at 96*. 

These temperatures are considerably higher than the com« 
mon estimation. 

A man's arm being introduced within a glass cylinder, it 
was duly closed at the end which embraced the head of the 
humerus ; the vessel being inverted, water at 97° was poured • 
in, so as to fill it. A ground brass plate closed the lower 
aperture, and a barometer tube communicated with the water 
at the bottom of the cylinder. This apparatus including the 
arm, was again inverted, so that the barometer tube became a 



• on muscular Motion. ' t^g 

g^ge, and no air was suffered to remain in the apparatus. On 
the slightest action with the muscles of the hand, or fore-arm, 
the water ascended rapidly in the gage, making librations of 
six and eight inches length in the barometer tube, on each 
contraction and relaxation of the musclesr* 

The remarkable eflfects of crimping fish by immersion in 
water, after the usual signs of life have disappeared, are worthy 
attention ; and whenever the rigid contractions of death have 
not taken place, this process may be practised with success. 
The sea fish destined for crimping are usually struck on the 
head when caught, which, it is said, protracts the term of this 
capability ; and the muscles which retain this property longest 
are those about the head. Many transverse sections of the 
muscles being made, and the fish immersed in cold water, the 
contractions called crimping take place in about five minutes ; 
but, if the mass be large, it often requires thirty minutes to 
complete the process. 

. Two fioimders, each weighing ig^G grains, the one being 
m a state for crimping, the other dead and rigid, were put into 
water at 4^^'', each bemg equally scored with* a knife. After 
half an hour, the crimped fish had gained in weight 5^ grains,, 
but the dead fish had lost 7 grains. The specific gravity of the 
crimped fish was greater th«i that of the dead fish, but a 
quantity of air-bubbles adhered to the surfaces of the crimped 
muscles, which were rubbed off before weighing ; this gas was 
not inflammable* 

The specific gravity of the crimped fish - - 1,105 

of the dead fish, after an equal 
immersion in water - 1,090. 

So that the accession of water specifically lighter thaa tha 



,24 JVfr. Carlisle's Lecture 

miiscle of fish, did not diminish the specific gravity of crimped 
muscle, but the contrary : a proof that condensation had taken 
place. 

A piece of cod-fish weighing twelve pounds, gsdned in weight, 
by crimping, two ounces avoirdupois ; and another less viva* 
cious piece, of fifteen pounds, gained one ounce and half.* 

The hinder limb of a frog, having the skin stripped off, and 
weighing 77y^ grains, was inmiersed in water at 54°, and suf- 
fered to remain nineteen hours, when it had become rigid, and 
weighed 100^ grains. The specific gravity of the contracted 
limb had increased, as in the crimped fish. 

Six hundred and thirty grains weight of the subscapularis 
muscle of a calf, which had been killed two days from the 
loth of January, was immersed in New River water at 45*. 
After ninety minutes, the muscle was contracted, and weighed 
in air 770 grains : it had also increased in specific gravity, but 
the quantity of air-bubbles formed in the intersticial spaces of 
the reticular membrane made it difiicult to ascertain the degree. 
. Some of the smallest fasciculi of muscular fil>res from the 
same veal, which had not been immersed in water, were placed 
on a glass plate, in the field of a powerful microscope, and 
a drop of water thrown over them, at the temperature of 54% 
the atmosphere in the room being 57^. They instantly began 
to contract, and became tortuous. 

On confining the ends of another fibril with little weights of 
glass, it contracted two-thirds of its former length, by similavt 

r 

* I am informed that the crimping of fresh water fishes requires hard water^ or 
such as does' not suit the purposes of washing with soap. This fact is substantiated 
by the practice of the London fishmongers^ whose experience has taught them to 
«mploy pump water> or what is commonly called hard water- 



OH muscular Motion. ^5 

treatment The same experiment was made on the muscular 
fibres of lamb and beef, twelve hours after the animals had 
been killed, with the like results. Neither vinegar, nor water 
saturated with muriate of soda, nor strong ardent spirit, nor 
olive oil, had any such efiect upon the muscular fibres. 

The amphibia, and coleopterous insects, become torpid at 
g^"". At g6^ they move slowly, and with diificulty ; and, at a 

• • • 

lower temperature their muscles cease to be irritable. The 
muscles of warm-blooded animals are similarly affected by cold. 

The hinder limbs of a frog were skinned and exposed to 
cold at 30"*, and the muscles were kept frozen for eight hours^ 
but on thawing them, they were perfectly irritable. 

The same process was employed in the temperature of 20% 
and the muscles kept frozen for twelve hours, but that did not 
destroy the irritability. 

In the heat of loo*, the muscles of cold-blooded animals faJl 
into the ocmtractions of death ; and at 1 lo"*, all those of warm 

I 

blood, as far as these experiments have been extended. The 
muscles of warm-blooded animals, which always contain more 
red particles in their substance than those of cold bkxxl, are 
sooner deprived of their irritability, even although their relative 
temperatures are preserved; and respiration in the former 
tribe is more essential to life than m the latter. 

Many substances accelerate the cessation of irritability in 
muscles when applied to ' their naked fibrils, such as all the 
narcotic vegetable poisons, mutiate of soda, and the bile of 
animals ; but they do not produce any other apparent change 
in muscles, than that of the last contraction. Discharges of 
electridty passed through muscles, destroy their irritability, 
but leave them apparency inflated with small bubbles of gas ; 

MDCCCV. £ 



»6 Mr. Carlisle's Lecture 

perhaps some combination obtains which decomposes the 
water. 

The four separated limbs of a recent frog were jskinned^ an^ 
immersed in different fluids ; viz. No, i , in a phial containing 
six ounces by measure of a saturated aqueous solution of liver 
of sulphur made with potash;. No. 2, in a diluted acetic acid, 
consisting of one drachni qf concentrated acid tO' six of water ; 
No. 3, in a diluted alkali<^ composed of caustic vegel;able alkali 
one drachm, of water six ounces ; No. 4, in pure distilled water. 

The phials were all corked, and the temperature of their 
conterits was 46*. y , - 

The limb . contained in the phial No. 1, after remainkig 
twenty minutes, had acquired a pale red colour, and the muscles 
were highly irritable. 

The limb in No. 2, after the same duration, had becomq 
rilgid, white, and swollen ; it was npt ftt all irritable. By re- 
moving the limb into a^iluted solution of vegetable alkali, the 
muscles were relaxed, but no signs of irritability returned. 

No. gi under all the former jdrcunastances, retained its preK 
vk>us appearance;s> and was iiritable, but less so than No. i; 

No. 4 had becQmie rigid? ^ikI thf; final ccfntraction had taken 
place. 

Other causes of the loss^ pf muscular irritability occur in 
pathological testimonies, somp examples: of which ^^y npt be 
ineligible for tlji^e pre£[ent subj^ct^ WorHra^n whosie^hands axe 
unavoidably exposed to the contact of white lead, are liable to 
what is called a palsy in the hands and wrists, from a torpidity 
of the muscles of the fore arm: This afFectkm seems to be 
decidedly local, because, m many instance/sij neither the brain, 
nor the other members, partake of th^ disorder ; and it oftenest 



f • _ I 

on ntuicular Motion. «^ 

afifects the right hand. An ingenious practical chemist in London 
has fre<j[uently experienfciid spasms and rigidity m the riiuscles 
of his fore arms, from afJbsioris of mtric acid over the cuticle 
of the hand and arm. The use of mercury occasionally brings' 
on a similar rigidity in the masseter' muscles. 

A smaller qugflitity of blood flows through a muscle diirih'g 
the state of contraction, than during the quiescent state, as is 
evinced by the pale colour of red muscles when contracted. 
The retardation of the flow of blood from the v«ns of the fore 
arm, during vensesection, when tlie muscles of the'Kmb ai^e-Ttep* 
rigid, and the increased flow afW alternate re!a^'trtiOris>M(tii^flf 
tlTprotability; that a temporary retardation of the blood in the 
muscular fibrils takes place during each contraction, and that 
\ts free course obtairts 'again during the relaxation. This state 
of the vascular syistem in a contracted muscle, does not, how- 
ever, explain the diminution of its bulk, although it may have 
some influence on the limb of a living animal. 

When muscles are vigorously contracted, their sensibility 
to pain is nearly destroyed ; this means is employed by jug- 
glers for the purpose of suffering pins to be thrust into the 
calf of the leg, and other muscular parts with impunity : it is 
indeed reasonable to expect, a prioriy that the sensation, and 
tile voluntary influence, cannot pass along the nerves at the 
Same time. 

In addition to the influences already enumerated, the human 
muscles are susceptible of changes from extraordinary occur- 
rences of sen^We' impreSsiofts. Long continued attention to 
interesting visible objects, bt* to audible sensations, are known 
to exhaust the muscular strength : intense thought and anxiety, 
weaken the muscular powers, and the passions of grief and 

£3 



28 Mr. Cabxisle's Lecture 

Tear pnoduce the^ same effect suddenly : whilst the contrary 
feelings, sudr as the prospect of immediate enjoyment, or 
moderate hilarity, give more than ordinary vigour. 
' It is a very remarkable fact in the history of animal nature^ 
that the mental operations may become almost automatic, and^ 
under such haUt; be kept in action, without any interval of 
rest> far beyond the time which the ordinary state df health 
permits, as in the examples of certain maniacs, who are enabled 
without any inconvenience^ to exert both mind and body fbr 
many days incessantly : The habits of particular modes of labour 
and exercise are soon acquired, after which, the actions become 
automatic, demand little attentk)n, cease to be irksome, and are 
effected with little fatigue : by this happy provision of nature, 
^e habit of industry becomes a source of pleasure, and the 
same appears to be extended to the dodle animals which cq« 
operate widi man in his labours. 

Three classes of muscles are found in the more complicated 
animals. Those which are. constantly governed by the will, 
or directing power of the mind, are called voluntary musdes. 
Another class, which operate without the consciousness of the 
mind, are denominated involuntary ; and a mixed kind occur 
in the example of respiratory muscles, which are governed by 
the will to a limited extent ; nevertheless the exigencies of the 
animal feelings eventually urge the respiratory movements in 
despight of the will. These last muscles appear to have become 
automatic by the continuance of habit. 

.The uses of voluntary muscles are attained by experience, 
imitation, and instruction : but some of them are never called 
into action among Europeans, as the muscles of the external 
ears, and generally the occipito-rfrontalis. The purely invo-^ 



on muscular Motion . ag 

limtary muscles are each acted upon by different substances^, 
which appear to be their peculiar stimuli; and these stimuli 
co-operate with the sensorial influence in producing their con- 
tractions : for example, the bile appears to be the appropriate 
stimulus of the muscular fibres of the alimentary canal below 
the stomach, because tlie absence of it renders those passages 
torpid. The digested aliment, or perhaps the gastric juice in a 
certain state, excites the stomach. The blood stimulates the 
heart, light the iris of the eye, and mechanical pressure seems 
to excite the muscles of the oesophagus. The last cause may 
perhaps be illustrated by the instances of comi^ression upon 
the voluntary muscles, when partially contracted, of which 
there are many familiar examples. Probably the muscles of 
the ossicula auditus are awakened by the tremors of sound ; 
and this may be the occasion of the peculiar arrangement ob** 
servable in the chorda tympani, which serves those muscles. . 

These extraneous stimuli seem only to act in conjunction 
with the sensorial, power, derived by those muscles from the 
gangliated nerves, because the passions of the mind alter the 
muscular actions of the heart, the alimentary canal, the respi- 
ratory muscles, and the iris ;. so that probably the respective 
stimuli already enumerated, only act subserviently, by awak* 
eliing the attenticm of the sensorial power, ( if that expression 
may be allowed,) and thereby calling forth the nervous in- 
fluence, which, from the peculiar organization of the great 
chain of sympathetic nerves, is effected without consciousness : 
for, when the attention of the mind, or the more interesting 
passions prevail, all the involuntary muscles act irregularly, 
and unsteadily, or wholly cease. The movements of the iris of 
the common parrot is a striking example of the mixed infltuence. 

The muscles of the lower tribes of animals, which are often , 



30 Mr. Carlisle's Lecture an muscular Motion. 

entirely supplied by nerves coming from ganglions, appear of 
this class ; and thus the animal motions are principally regu- 
lated by the external stimuli, of which the occurrence seems 
to agree with the animal necessities : but the extensive illus- 
trations which comparative anatomy affords on this point, are 
much too copious for any detail in this place. 

There are two states of muscles, one active, which is that of 
contraction, the other, a state of ordinary tone, or relaxation, 
which may be considered passive, as far as it relates to the 
mind ; but the sensorial or nervous power seems never to be 
quiescent, as it respects either the voluntary or involuntary 
muscles during life. The yielding of the sphincters appears to 
depend on their being overpowered by antagonist muscles, 
rather than on voluntary relaxation, as is commonly supposed. 

I have now finished this endeavour to exhibit the more recent 
historical facts connected with muscular moticm^. 

It will be obvious to every one, that much remains to be done, 
before any adequate theory can be proposed. I have borrowed 
from the labours of others, without acknowledgement, because 
it would be tedious to trace every fact, and every opinion to its 
proper authority : many of the views are perhaps peculiar to 
myself, and I have adduced many general assumptions and 
conclusions, without offering the particular evidence for their 
confirmation, from a desire to keep in view the remembrance of 
retrospective accounts, and to combine them with intimations 
for future research. The due cultivation of this interesting 
pursuit cannot fail to elucidate many of the phenomena in 
question, to remove premature and ill founded physiological 
opinions, and eventually to aid in rendering the medical art 
more beneficial, by establishing its doctrines on more extensive 
and accurate views of the animal economy. 



Cs> 3 



IL Experiments for ascertaining how far Telescopes will enable us 
to determine very small Angles y and to distinguish the real from 
the spurious Diameters of celestial and terrestrial Objects : with 
an Application of the Result of these. Experiments to a Series of 
Observations on the Nature and Magnitude of Mr. Harding's 
lately discovered Star. By William Herschel, LL. D. F. R. S. 



Read December 6, 1804. 

The discovery of Mr. Harding having added a moving 
celestial body to the list of those that were known before, I 
was desirous of ascertaining its magnitude ; and as in the ob- 
tervations which it was necessary to make I intended chiefly 
to use a ten-feet reflector, it appeared to me a desideratum 
highly worthy of investigation to determine how small a dia- 
meter of an object might be seen by this instrument. We know 
that a very thin line may be perceived, and that objects may 
be seen when they subtend a very small angle ; but the case I 
wanted to determine relates to a visible disk, a round, well 
defined appearance, which we may without hesitation aflirm to 
be circular, if not spherical. 

In April of the year 1774, I determined a similar question 
relating to the natural eye : and found that a square area could 
not be distinguished from an equal circular one till the diameter 
of the latter came to subtend an angle of 2' 17". I did not 
think it right to apply the same conclusions to a telescopic view 



3^ Dr. Herschcl's Experiments on the Means 

of an object, and therefore had recourse to the following 
experiments. 

1st Experiment, with the Heads of Pins. 

I selected a set of pins with round heads, and deprived them 
of their polish by tarnishing them in the flame of a candle. 
The diameters of the heads were measured by a microscopic pro- 
jection, with a magnifying power of 80. These measures are 
so exact, that when repeated they will seldom differ more than 
a few ten thousandths parts of an inch from each other. Their 
sizes were as follows: ,1375 ,0863 ,0821 ,0602 ,0425. I 
placed the pins in a regular order upon a small post erected in 
my garden, at 2407,85 inches from the centre of the object 
mirror of my ten-feet reflecting telescope. The focal length 
of the mirror on Arcturus is 1 19,64 inches, but on these objects 
125>9- The distance was measured with deal rods. 

When I looked at these objects in the telescope, I found 
immediately that only the smallest of them, at this distance 
could be of any use ; for with an eye-glass of 4 inches, which 
gives the telescope a magnifying power of no more than 31,5, 
this pin's head appeared to be a round body, and the view left 
no doubt upon the subject. It subtended an angle of s",64 
at the centre of the mirror, and the magnified angle under 
which I saw it was 1' g^'^jS. This low power however required 
great attention. 

With a lens 3,3, power 38,15, 1 saw it instantly round and 
globular. The magnified angle was 2' i8'',9. 

With a magnifying power of 231,8,* I saw it so plainly that 

* The powers have been strictly ascertained as they are at the distance where 
these objects were viewed. 



of ascertaining the Magnitude of small celestial Bodies. 33 

the little notch in the pin's head between the cpils of the wire 
making the head, appeared like a narrow black belt sur- 
rounding the pin in the manner of the belts of Jupiter. This 
notch by the microscopic projection measured ,00475 inch ; 
and subtended an angle, at the centre of the mhror, of o"j^y. 

With 303,5 I saw the belt still better, and could follow it 
easily in its contour. 

With 439,0 1 could see down into the notch, and saw it well 
defined within. 

With 522,3 tlie pin's head was a very striking globular 
object, whose diameter might easily be divided by estimation 
into ten parts, each of which would be equal to 0^,364. 

With Q^sfi I saw all the same phenomena still plainer. 

The result of this experiment is, that an object having a 
jdiameter ,0425 may be easily seen in my telescope to be a 
round body, when the magnified angle under which it appears 

is 2f 18^',^, and that with a high power a part of it, subtending 

' . ... 

an angle of 0^,364 may be conveniently perceived. 

When I considered the purpose of this experiment, I found 

__^ • * ' • 

the result not sufficient to answer my intention ; for as the size 
of the object I viewed obliged me to use a low power, a doubt 
arose whether ^he instrument would be equally distinct when 
a higher should be required. To resolve this question, it was 
necessary either to remove my objects to a greater distance^ 
or to make them smaller, 

^d Experiment^ with small Globules of Sealing-wax. 

" • • . . > 

I melted some sealing-wax thinly spread on a broad knife, 

■ * * • - . • 

and dipt the point of a fHie needle, a little heated, into it, which 
took up a small globule. With some practice I soon acquured 

MDCCCV. F 



34 Or. Hbrschel's Experiments on the Means 

• • • 

the art of making them perfectly round and extremely smalL 
To prevent my seeing them at a distance in a different aspect 
from that in which they were measured under the microscope, 
I fixed the needles with sealing-wax on small slips of cards 
before the measures were taken. 

Eight of these globules of the following dimensions ,0466 
,0325 ,0290 ,02194 ,0210 ,0169 ,0144 ,00763 were placed 
upon the post in my garden, and I viewed them in the telescope. 

With a power of 231,8 I saw all the first seven numbers 
well defined, and round, and could see their gradual decrease 
very precisely from No. 1 to No. 7. 

With 303,5 I saw them better, and had a glimpse of No. 8, 
but could not be sure that I saw it distinctly round ; though 

the magnified angle was 3' i8",2. 

* • • 

With 432,0 they are all very palpable objects, and, as a 

solid body. No. 8 may be seen without difficulty ; at the centre 

of the mirror it subtends an angle of o"fis$. With attention 

. we may also be sure of its roundness ; but here the magnified 

angle is not less than 4' 42",!. 

With 522,3 I s^^ them all in great perfection as spherical 
bodies, and the magnitude of No. 7 may be estimated in quartern 
of its diameters. The angle is i'',253, and one quarter of it is 
o'',3i3. No. 8 may be divided into two halves with ease ; each 
of which is o",327. 

With 925,4 I saw No. 8 still better ; but sealing-wax is not 
bright enough for so high a power. 

By. this experiment it appears, that with a globule so small 
as ,00763 of a substance not reflecting much light, the mag- 
nified angle must be between 4 ancf 5 minutes before we can 
see it round. But it also appears that a telescope with a sufficient 



L. 



ef ascertaining the Magnitude of small celestial Bodies. 35 

power, will show the disk of a faint object when the angle it 
subtends at the naked eye is no more than o",6s^. 

^ 3^ Experiment, with Globules of Silver. 

a^ the Bbjects made of sealing-wax, on account of their 
colour, did not appear to be fairly selected for these investiga- 
tions, I made a set of silver ones. They were formed by 
running the end of silver wires, the 305th and S4«oth part of 
an inch in diameter, into the flame of a candle. It requires 
some practice to get them globular, as they are very apt to 
assume the shape of a pear ; but they are so easily made that 
we have only to reject those which do not succeed. 

Thirteen of them, in a pretty regular succession of magni- 
tude, were selected and placed upon the post. Their dimensions 
were ,03956 ,0371 ,0329 ,0317 ,0272 ,0260 ,0187 ,^0178 
,0164 ,0125 ,01137 ,00800 ,00556. 

For the sake of more conveniency I had removed my tele- 
scope from its station in the library to a work-room. The 
distance of the objects from the mirror of the telescope, mea- 
sured with deal rods, was here only 2370,5 inches ; and the 
focal length of the mirror, the magnifying powers of the 
telescope, and the angles subtended by the objects have been 
calculated accordingly. 

With 522,7 I see all the globules, from No. 1 to No. 13, 
perfectly well, and can estimate the latter in quarters of its 
diameter. The angle it subtends at the centre of the mirror is 
0^484 ; and one quarter of it is o'', 121. 

With the same power I see the wires which hold the balls^ 
60 well that eweh the smallest of them may be divided into 

F2 



* - - 

S6 Dr. Herschel's Experiments on the Means , 

half its thickness. It measures ,00237; ^^^ angle is o",2o6; 
and half of it o'',i 03. 

With 453,0 I see all the globules of a round form, and can 
by estimation divide No. 13 into two halves. Th'- z*^^*^ ^^^ 
angle is here 3' 29'',©, Jbut as its diameter could uy estimation 
be divided into two parts, the round form of a globule some- 
what less might probably have been perceived, so that the 
magnified angle would perhaps not have much exceeded the 
quantity 2' i8",9 that has been assigned before. 

After some time the weather became much overcast, and as 
the globules were placed over a cut hedge, the leaves and 
interstices of which did not reflect much light, they received 
the greatest part of their illumination from above. This made 
them gradually assume the shape of half moons placed hori- 
zbntally. The dark part of these little lunes, however, did not 
appear sensibly less than the enlightened part, so that there 
could not be any thing spurious about them. 

By this experiment we find that the telescope acts very well 
with a high power, and will show ah object subtending only 
o'',4j84 so large that we may divide it into quarters of its 
diameter. 

j^th Experiment, with Globules of Pitch, Bee's^wax, and 

Brimstone. 

, I had before objected to sealing-wax globules on account of 
their dingy-red colour ; in the last experiment ' a doiibt was 
raised with regard to the silver ones, because they were per- 
haps too glossy. \n order to compare the effect of different 
substances together in the same atmosjphere, I piit up three 



of ascertaining the Magnitude of small celestial Bodies. 37 

globules. No. 1 of silver, diameter ,01137 ; ^o- ^ ^^ sealing- 
wax ,01 125 ; No. 3 of pitch ,00653. 

With 522,7 I saw No. 1 round, and could estimate ^ of its 
^^'^"^^^^ s.X^^ angle is o'^gSg; ^ of it is o",247. 

rsa?^ liro: a round, but of a dusky-red colour. It is not 
nearly so bright as No. 1 ; nor does it appear quite so large 
as the proportional measure of the globules would require. I 
can estimate ^ of its diameter. The angle is o^',gyg ; and i of 
it is 0^,326. 

No 3 reflects so little light that I can barely perceive the 
globule, but not its form ; and yet it subtends an angle of 
o",568. . 

To discover whether this ought to be ascribed intirely to the 
want of reflection of the pitch, I took up some white melted 
bee's-wax, by dipping the fine point of a needle perpendicu- 
larly into it. This happened to be only half a globule, and its 
diameter was ,0105. 

When I examined the object with 593 I saw it with great 
ease, and could estimate -^ of its diameter. The angle is 0^^914 ; 
and i of it is 0^,228. I saw also that it vvas but half a globule* 

I took up another, that I might have a round one ; but found 
that again I had only half a globule. It was so perfectly bi- 
sected, that art and care united could not have done it better. 
Its diameter was ,0108. In the telescope I saw its semiglobular 
form, and could estimate ^ of its diameter. 

By some further trials it appeared, that a perfect globule of 
this substance could not be taken up, the reason of which it is 
not difficult to perceive ; for as it melts with very little heat, 
it will cool the moment the needle is lifted up ; and the surface, 
which cools first, will be flat 



J 



gS Dr. Herschel's Experiments on the Means 

The roundness of the objects being a material circumstance, 
I melted a small quantity of the powder of brimstone, and 
dipping the point of a. needle into it, I found diat globules, 
perfectly spherical and extremely small, might be taken up. 
I had one of them that did not exceed the 64,0th part of an 
inch in diameter. 

When four of the following sizes, ,00962 ,009125 ,00475 
/)02375 were placed on the post in the garden and viewed 
from the work-room station with 522,7 1 saw No, 1,2, and 3, 
round, but No. 4 was invisible. 

These globules reflect but little light, so that they are not 
easily to be distinguished from the surrounding illumination of 
the atmosphere ; but when I placed some dark blue paper a 
few inches behind them, I then could also perceive No. 4 as a 
round body. The angle it subtends is o'',207. 

gth Experiment with Objects at a greater Distance. 

Having carried the minuteness of the globules as far as 
appeared to be proper, I considered that a valuable advantage 
would be gained by increasing the distance of the objects. 
The experiments might here be made upon a larger scale, and 
the body of air through which it would be necessary to view 
the globules would bring the action of the telescope more 
jupon a par with an application of it to celestial objects. 

On a tree, at 9620,4 inches from the object mirror of the te- 
lescope, I fixed the sealing-wax globules of the 2d experiment. 
The distance was measured by a chain compared with deal 
rods, and by calculation the altitude of the objects has been 
properly taken into the account. 

With 502,6 No. 1 is a very large object ; so that were I to 



of ascertaining the Magnitude of small celestial Bodies. 39 

see a celestial body under the same angle, I could never mis- 
take it for a small star. The angle it subtends is o'^999• * 

I see the diameters of No. 2 and 3 very clearly, and can 
divide them by estimation into two parts, half of No. 3 is o'^3i 1 . 

I see No. 4 and 5 as round bodies, but cannot divide them 
by estimation. The diameter of No. 5 is 0^^,45. No. 6 may 
also be seen, but 7 and 8 are invisible. 

These objects reflecting too little light, the silver globules 
of the 3d experiment were placed on the tree. It will be right 
to mention that they were all so far tarnished by having been 
out in the open air for more than a fortnight, that no improper 
reflection was to be apprehended. 

The air being uncommonly clear, I saw with 502,6 the glo- 
bules No. 1 , 8,3, 4/ 5, and 6, as well defined black balls. I 
could easily distinguish ^ of the diameter of No. 6 ; which is 

o",i39- 
With 415,7 I saw them all round as far as No. 10 included. 

With 502,6 Isaw No. 9 and 10 very sharp and black, and 

could divide No. 10 into two parts, eadi of which would be 

0^134. 

With a new lens, power 759,7, I saw No. 10 better than 

with 502,6, and could with ease distinguish it into halves, or 

even third parts of its diameter, f of it is 0^,089. 

With 223,1 I saw them all as far as No. 10 included as 
visible objects, but the^ smallest of them were mere points. 
No. 6 might be divided with this power into two parts ; each 
being ©'',279. 

With 292,1 I saw No. 10 sharp and round. The magnified 
angle is only i' i8'',3. One half of No. 6 may be perceived 
with great ease. 



40 I>. Hsrschel's Experiments on the Means 

The weather being as favourable as possible, I saw with 
4i5>7 the globule No. lo round at first sight; the magnified 
angle is i^ 5l'^t. I can see No. is steadily round ; the angle 
is o'^iys. It is however a mere point, and divisions of it cannot 
be made. 

With a new lo-feet reflector, power 540, the globule No. 10 
is beautifully well defined, and ^ of it may be estimated; the 
angle is o",268 ; |- of it is o'^l34. 

With the old reflector, and 502,6, I see No. 12 steadily 
round. No. 7, 11, and 13, have met with an accident, and 
could not be observed. 

6th Experiment with illuminated Globules. * 
The night being very dark, 8 silver globules, from ,0891 
to ,00596 in diameter were placed on the post, apd illuminated 
by a lantern held up against them. 

With 532,7 I saw them all perfectly well, but the small 
quantity of light thrown on them was not suflicient to make 
angular experiments upon them. As objects I saw them as 
easily as in the day time. Probably the phases of the illumi- 
nated disjks I saw might be such as the moon would $how when 
about 9 or 10 days old. The angle of No. 8, h^d it been full, 
would have been 0^,51 9. A better way of illumination might 
be contrived. 

SPURIOUS DIAMETERS OF CELESTIAL OBJECTS. 

Observations and Experiments, with Remarks. 

July 17, 1779- With a 7-feet reflector, power a8o, I saw 
the body of Arcturus, very round and well .defined. I saw 



of ascertaining the Magnitude of small celestial Bodies. 41 

ulso ^ Ursse mijoris and other stars equally round, and as 
well defined. 

REMARKS. 

( 1 . ) As these diameters are undoubtedly spurious, it follows 
that, with the stars, the spurious diameters are larger than the 
. real ones, which are too small to be seen. 

Sept. 9, 1779. The two stars of s Bootis are of unequal dia- 
meters ; one of them being about three times as large as the 
other. 

(2.) From this and many estimations of the spurious dia- 
meters of the stars* it follows, not only that they are of 
different sizes, but also that under the same circumstances, their 
dimensions are of a permanent nature. 

August 25, 1780. The large star of y Andromedae is of a 
very fine reddish colour, and the small one blue. 

(3.) By this and many other observations it appears, that 
the spurious diameters of the stars are differently coloured, 
and that these colours are permanent when circumstances are 
the same. 

Nov. ag, 1779. I viewed » Geminorum with a power of 449, 
and saw the two stars in the utmost perfection. The vacancy 
between them was about i|- diameter of the largest. I found 
when I looked with a lower power, that the proportion between 
the distance and magnitude of the stars underwent an alteration. 
With 222, the vacancy was 1^ diameter, and with 112, it was 
no more than 1 diameter of the smallest of the two stars, or 
less. 

( 4. ) By many observations, a number of instances of which 

• See Catalogues of double Stars* PhiL Trans, for 1781^ p. 115; and for 1785, 
page 40. 

MDCCCV. G 



42 Dr. Herschel's Experiments on the Means 

may be seen in my catalogues of double stars, their spurious 
diameters are lessened by increasing the magnifying power, 
and increase when the power is lowered. 

(5.) It is also proved by the same observations, that the 
increase and decrease of the spurious diameters, is not inversely 
as the increase and decrease of the magnifying power, but in 
a much less ratio. 

Nov. 13, 1782. The two stars of the double star 40 Lyncis, 
with a power of 460 are very unequal ; and with 227 they are 
extremely imequal. 

(6.) From this we find, that the magnifying power acts 
unequally on spurious diameters of different magnitudes ; less 
on the large diameters, and more on the small ones. 

Aug. 20, 1781. I saw 6 Bootis with 460, and the vacancy 
between the two stars was 1^ diameter of the large one. I 
then reduced the aperture of the telescope by a circle of paste- 
board from 6,3 inches to 3,5, and the vacancy between the 
two stars became only ^ diameter of the small star. 

The proportion of the diameters of the two stars to each 
other was also changed considerably ; for the small one was 
now at least - if not ^ of the large one. 

( 7. ) Tliis shows that when the aperture of die telescope is 
lessened, it will occasion an increase of the spurious diameters, 
and when increased will reduce them. 

(8.) It also shows that the increase and decrease of the 
unequal spurious diameters, by an alteration of the aperture of 
the telescope, is not proportional to the diameters of the stars : 

(9. ) But that this alteration acts more upon small spurious 
diameters, and less upon large ones. 

Aug. 7, 1783. I tried some excessively small stars near y 



of ascertaining the Magnitude of small celestial Bodies. 43 

Aquilse. When y was perfectly distinct and round, the ex- 
tremely small stars were dusky and ill defined ; the excessively 
small ones were still less defined. As there are stars of all sizes 
in this neighbourhood, I saw some so very minute, that they 
only had the appearance of a small dusky spot, approaching to 
mere nebulosity. By very long attention I perceived many small 
dusky nebulous spots, which had it not been for this attention 
might have been in the field of view without the least suspicion. 

( 10. ) From this we find that stars, when they are extremely 
small, lose their spurious diameters, and become nebulous. 

July 7, 1 780. I saw the spurious diameter of Arcturus gra- 
dually diminished by a haziness of the atmosphere till it 
vanished intirely. 

A more circumstantial account of this observation has already 
been given; and some other causes that affect the spurious 
diameter of the stars, have been pointed out in the same paper, 
6uch as tremulous air, wind, and hoar-frost.* 

January 31, 1783. The star in the back of Columba makes 
a spectrum, about 5 or &' long, and about «'' broad, finely 
coloured by the prismatic power of the atmosphere at this 
altitude. 

July a8, 1783. Fomalhaut gives a beautiful prismatic spec- 
trum, on account of its low situation. 

July 17, 1781. With a new lens, power between 5 and S 
hundred, I saw ^ Aquarii, and found the vacancy between the 
two stars exactly 2 diameters. With my old one, power only 
460, it was full 2 diameters. As it should have been larger 
with the high power than with the low one, it shows that the 
best eye-lens will give the least spurious diameter. 

• Sec Phil. Trans, for 1803, page 224. 

G 2 



44 D^' Herschel's Experiments on the Means 

Oct. 12, 178a. I tried a new plain speculum, made by a very 
good workman, and found that when I viewed a Geminorum 
with 460, the vacancy between the two stars was barely li 
diameter, but the same telescope and power with my own 
small speculum, made the distance s diameters, so th^t the 
figure of this mirror affects the spurious diameters of the stars. 

(11.) Hence we may conclude that many causes will have 
an influence on the apparent diameter of the spurious disks of 
the stars ; but they are so far within the reach of our know- 
ledge, that with a proper regard to them, the conclusion we 
have drawn in Rem. ( s. ) *' that under the same circumstances 
** their dimensions are permanent/' will still remain good. 

SPURIOUS DIAMETERS OF TERRESTRJAt OBJECTS, WITH SIMILAR 

REMARKS. 

7^A Experiment with Silver Globules. 

A number of silver globules were put on the post, before 
they had been tarnished ; and the sun shone upon them. When 
I viewed them in the telescope, there was on each of them a 
lucid appearance resembling the spurious disk of a star. X 
could distinguish this>ight spot from the real diameters of 
the globules perfectly well, and foui>d it much less than they, 
were. 

Rem. ( 1 . ) Hence we conclude that the terrestrial, spurious 
disks of globules are less than the real disks ; whereas we 
have seen, in Remark ( 1* ) of the celestial spynous disks, that 
these are larger thaji the real ones. 



of ascertaining the Magnitude of small celestial Bodies. 45 

Sth Experiment. 

The luminous spots, of spurious disks of the globules were 
of unequal diameters. The globule No. 1 had the largest disk, 
9nd the smaller ones the least ; and the gradation of the sizes 
jbllowed the order of the numbers. 

( s&. ) This agrees with the spurious^^ ^sksof celestial objects: 
the stars of the first, second, and third magnitude having a 
larger spurious disk than those that are of inferior magnitudes. 

gth. Experiment. 

I found that there was a considerable difference in the colour 
of the spurious disks ; c»ie of diem was of a beautiful purple 
colour, another was. inclined to orange, a large one was straw 
coloured, a small one pale-^asb coloured, and most of tfaena 
were bluish-wlute. 

( 3* ) With respect to colours, therefore, die terrestrial also 
agree with the celestial spurious disks. 

10th Experiment. 

. I made two globules of difiefent diameters, and placed them 
very near each other, so that their spurious disks might re- 
semble those of a double star ; this succeeded perfectly well. 
I: viewed them with different powers. 

With 1 y^y the vacancy between them is f diameter of the 
large star. 

With 23a, it is 1^ diameter. 

With 303,8, it is i|- diameter. 

With 4,3»,3, it is 1^. 

(4.) This experiment proves that the spurious diameters 



46 Ih-, Herschel's Experiments on the Means , 

of the globules are also in this respect like the spurious disks 

of the stars ; for they are proportionally lessened by increasing 

the magnifying power, and increased when the power is 

lowered. 

(5.) When the estimations are compared with the powers, 

it will also be seen that the increase and decrease of the spurious 

disks of the globules is not inversely as the powers, but m a 

much less ratio. 

11th Experiment. 

Two other globules of different sizes were examined ; and 

With 706,3 they were pretty unequal. 

With 522,7 they were considerably unequal. 

With 303,8 they were very unequal. 

(6.) This proves that the effect of magnifying power is 
unequally exerted on spurious diameters; and that, as with 
celestial objects, so with terrestrial, this power acts more on 
the small spurious disks than on the large ones. 

. 12th Experiment. 

I viewed a different artificial double star with 522,7, and 
keeping always the same power, changed the aperture of the 
telescope. 

With the inside rays I found them considerably unequal, and 
2^ diameters of the largest asunder. The spurious disks are 
perfectly well defined, round, and of a planetary aspect. 

With all the mirror open, they are also round and well 
defined. 

With the outside rays, they are near 4 diameters of the largest 
asunder, and are also round and distinct, but surrounded with 
flashing rays and bright nodules in continual motion. 



qf ascertaining the Magnitude of small celestial Bodies. 47 

( 7. ) This shows that the spurious terrestrial disks, in this 
respect again resemble those of the stars ; increasing when 
the aperture is lessened, and decreasing when it is enlarged. 

13/A Experiment. 

With the same magnifying power 432,3, but a change of 
aperture, I viewed two equal globules, and two unequal ones. 

With the inside rays the equal globules were 1 diameter 
asunder. 

With all the mirror open, they were 1^ diameter asunder. 

And with the outside rays they were s diameters asunder. 

The unequal globules, with the inside rays, were a little 
unequal, and 1 diameter of the large one asunder. 

With the outside rays they were considerably unequal, and 
2 diameters of the large one asunder. 

( 8. ) By these experiments it is proved, that the increase 
and decrease of the diameters occasioned by different apertiures 
is not proportional to the diameters of the spurious disks. 

( 9. ) But that the change of the apertures acts more on the 
small, and less on the large ones. 

i^th Experiment. 

No. 1 of a set of globules, has the largest spurious diameter. 
No. 3 is larger than No. 2 ; whereas No. 2 has the largest real 
diameter. It is inclined to a greenish colour. No. 3 is now 
reddish, and is larger than No. 1 , which is at present less than 
No. 2. No. 1 grows bigger, and is now the largest. 

The sun which had been shining, was obscured by some 
clouds, but the spurious diameters of the globules I was viewing 



4S Dr. HckscHEL's Experiments on the Means 

remained visible, and were almost as bright as when the sun 
shone upon them. 

I saw one of the globules lose its spurious diameter while 
the sun continued to shine. After some time the spurious dia- 
meter came on again, and very gradually grew brighter, but not 
larger. The colour of one of the globules being of a beautiful 
purple, changed soon after to a brilliant white. 

The sun being obscured by some clouds, a globule lost its 
spurious diameter, and acquired the shape of an half moon, of 
the size of the real disk or diameter of the globule. I saw the 
sun break out again, and the half moon was gradually trans- 
formed into a much smaller spurious disk. 

( lo. ) The spurious disks of globules are lost for want of 
proper illumination, but do not change their magnitude on that 
account. The brightness of the atmosphere in a fine day is 
sufficient to produce them ; though the illumination of the sun 
is generally the principal cause of them. 

( 1 1 . ) The diameters of spurious disks are liable to change 
from various causes ; an alteration in the direction of the illu- 
mination will make the reflection come from a different part of 
the globule, which can hardly be expected to be equally po- 
lished in its surface, or of equal convexity every where, being 
very seldom perfectly spherical ; but as upon the whole the 
figure of them is pretty regular, the apparent diameter of the 
spurious disks wrill generally return to its former size. 

i^th Experiment y with Drops of Qfiicksilver. 

At a time of the year when bright sun-shine is not very 
frequent, I found that my silver globules would seldom give 



oj asceitmilng^e MagftHmk bf strndl vekslial Bodies. 49 

irie ^ttl^ d^^iea^tMity Tor le^jiesrub^i on spurioUs disks; to 
obvUlte thiit iiKdnvfem^iiise^ Insefl small drops of quicksilver. 
They are more lucid, and will give a bright spot vv^ith very 
IK^e MAsliiaev 'M^aiiy (tf. these dro|)s of all sizes were exposed 
VLpCfA 4k i^iaite of glanvdnd Bdme dn slijps.of steel. The manage- 
ment of them is a little different from that of the globules. 
For in oiider to repre^^it a dmible star these must be ^ced 
one almost behtriffl th« other, as otherwise they cannot be 
brought near «tiotigh without running together. The following 
general observation will include all die necessary particulars. 

Th6 bdglit ^pots on drops of quicksilver are v)ery small 
compared to the size of the dJroqps. 

They ^e hot proportional to the magnitude of the drops, 
though leM oTi the small tine^ and greater on large ones. 

lli Sdi66 of the large dties the bright spot is about ^ or J^ 
<rf the diameter of die drop. 

The ti^^tudfe of tlieltniiHnouB a^ts is liable to changes, but 
is rather mori^ peritiaiKnt thati with thi^ Isilver gk)bules. 

There is a little diiferenise in the colour of the luminous 
spots ; they aee generally of a brilliant white^ but sometimes 
they indline to yelldw^ gnd the small cmes to ash'-colour. 

With high m^niffying powers they are very well defined, 
and, on account of their brightness, will bear these powers 
better than the silver globules. 

If M and m, stand for the diameters of the large and small 

mirror of my telescope, then vsdll ah apefture = \/ 1- m 

give half the light of the telescope. With this I examined 
two of the drops, and found the luminous spots upon them 
with 

MDCCCV. H 



50 Dr. IIerschel's Experiment on the Means 

935^4 nearly equal, and 2^ diametars^iof the largiest^undeF. 

706,3 nearly equal, and above 9 diazn^ters of the largest 
asunder. 

432,3 pretty unequal, and s.diameters.of the largest asunder. 

177,0 considerably uneqiial, and 1^- diameter of the Utrgest 
asunder. 

I examined also two other drops, with different apertures, 
without changing the power, which was 706^3, 

With the inside rays they were very little unequal, and ^ 
diameter of the largest asunder. 

With the outside rays they were considerably unequal, and 
1^ diameter of the largest asunder. 

From what has been said^ it appears that all the, reixtarks 
which have been made with regard to the spurious disks of 
the silver globules are confirmed by the luminous spots on the 
drops of quicksilver. There is a difference in- the proportion 
which the spurious disks on quickisilver bear to the drops, and 
that on the silver globules to the size of the globules; the 
latter also give a greater variety of colours and itiagnitud es 
than those on quicksilver ; these are circumstances of which 
it would be easy to assign the cause, but they can be of no 
consequence to the result we have drawn from the experiment. 

i6tk Experiment f with black and white Circles. 

I tried to measure some of the spurious disks b y projecting 
them on a scale with a moveable index, but foimd tlieir dia- 
meters were too small for accuracy by this method ; fo r this 
reason I had recourse to artificial measuring-disks, and pre- 
pared a set of eleven white circles on a black ground, and 
eight black ones on a white ground. In order to guard against 



of ascertainmg tbe\M9gnft^4^^^ ^^^r celestial Bodies. 5.1 

deeepttcms, I fixed th^dm miv, ftgamsl; a ^ablet 1 54 inches from 
the eye, where'it was intei^ded tpj^ject the spurious disks of 
the globules, and 6xamin^ them at that distance with the 
naked eye. Comparing ,then the size of the black to the white, 
I judged No. 1 .of the black to be a little larger than No. 6 of 
the white circles. By a measure taken afterwards, it appeared 
that the black one was ,40 and the white ,39. Without sup- 
posing that every estimation may be made at this distance with 
equal accuracy, to the hundredth part of an inch, it is suffi- 
ciently evident that no material deception can take place in 
estimating by either of the sets of circles on account of their 

colour- 

%*^th Experiment^ with different Illumination. 

. :. A simile exp^rini^nt was iq^de in the microscope, by which 
.the globules W)^re measured. Two of them were placed on the 
measuring stand, and with an illumination from below, they 
appeared black, and were projected on white paper. Th^ dia- 
meter of ead>: globule and the distance between them were 
then measured. After this,i caused the illumination to come 
from above, and the globules being now of a silvery white, 
were projectsed on a slate. In this situation, when I repeated 
the former measures^ no difference could be perceived. 

18M Experiment. Measures of spurious Disks. 

. The spurious disk of a globule was then projected on the 
tablet where the white circles were placed. While I was com- 
paring it with No. 4, which is ,31 in diameter and estimated it 
to be a little less than4he circle, the spurious disk grew brighter; 
but it remained still of the same size ; so that a variation ii^ 
the quantity of the illumination will make no difference. 

H2 



S% Dr. Herschel^s ExffemUnts m. tint Means 

Every thing being n6w airaHged for the measuremest, I 
viewed the spurious diameter, with a magnifying pawer of 
522,7, and compared it to t^ dreles which succeeded each 
other by small differences^ of magnitude. 

With all the mirror, from the centre to 8,8 inches (^)en, tfee 
diameter of the spurious disk was ,31 inches. 

With 6,3 inches open, it was less than ,40 and larger than 

^355- 
With 5 inches open, it was ,40. 

With 4 inches open, it was ,42. 

With 3 inches open, it was ,465 nearly. 

From these measures it might be supposed that by lessening 
the quantity of light, we bring on a certain indistinctness which 
gives more diameter to the spurious object ; to proVe that this 
is not the cause of the increase, I used the following apertures. 

With an annular opening from 6,5 to 8,8 inches, tb@ spurious 
disk was rather less than ,18. 

With another from 5 to 8,8 it was exactly ,18. 

With an opening from 4 to 6^ it was ,»9. 

With another from 1,6 to 4 it was ,42. 

(12.) Now since the outside rim from 6,5 to 8,8, whidi 
reflected less than half the light of the mirror, produced a 
spurious disk less than^ ,18 in diameter, and the whole light as 
we have seen gave a disk of ,3 1 , it is evidently not the quantity 
of the light, but the part of the mirror from which it is re- 
flected, that we are to look upon as the cause of the magnitude 
of the spurious disks of objects. 

( 13. ) These measures therefore point out an improvement 
in my former method of putting any terrestrial disk we suspect 
to be spurious to the test. For the inside rays of a mirror, as 



of ascirtaining ihi Magmiutk (f small celestial Bodies. 53 

before, wiU increase the diamj^ter of these disks, but the mitside 
rays alcme will have a greater effect in reducing k, than whea 
die inside rays are left to join with them . 

\Qth Experiment, Trial of Estimations. 

I placed two silver globules at a small distance from each 
other upon the post, but without measuring either the globules 
or their distance. When I viewed them with 522,7 they ap- 
peared }X\ the shape of two half moons in aici horizoiiUal situa- 
tion. The unenlightened parts of them were also pretty distkictly 
visible. I estimated the vacancy between the cusps of the lunes 
to be j: diameter of the lajrgest. 

On measuring the diameters and distance! under the micro- 
scope, it appeared that the largest was ^31^; a quarter of 
whicb is ,0078. The distance of tihe globules from each other 
measured ,011 1. The difierence ia the estimation fiOQ^ is less 
than y§^ part of an inch. 

The experiment was repeated with a change of the distance 
of the globules from each other. They were then estimated to 
be less than the diameter of the large one asunder, but full 
that of the small one. When they were measured it was found 
that their distance was ,02608, and the diameter of the small 
^ one was 50247, which estimation is still more accurate than 
the former. 

2,0th Experiment. Use of the Criterion. 

It remained now to be ascertained whether these half moons 
were spurious or real ; for although I could also imperfectly 
perceive the dark part of the disks of the globules, yet a doubt 
would arise whether the two halves were really of equal 



54 X^^* Herschel's Experiments an the Means 

magnitude ; to resolve this question, I viewed them first with 
the inside rays of the mirror, then with the outside, and found 
that in both cases the distance of the lunes remained without 
the least alteration. I viewed them also with the whole mirror 
open, but it occasioned no change. 

^ist Experiment. Measures of the comparative Amount of the 
spurious Diameters^ produced by the Inside and Outside Rays. 

I divided the aperture of the mirror into two parts, one 
from o to 4,4 and the other from 4,4 to 8,8 inches. When I 
measured the spurious diameter of a globule, the inside rays 
made it ,40; with all the mirror open it was ,31 ; and with 
the outside rays it was ,S2. 

( 14. ) From this we may conclude that the diameters given 
by the inside rays, by all the mirror open, and by the outside 
rays, are in an arithmetical progression ; and that the inside 
rays will nearly double, the diameter given by the outside. It 
remains however to be ascertained whether this will hold good 
with spurious disks of various magnitudes. 

It will not be necessary to carry the divisions of the aperture 
farther ; for as the application of these experiments is chiefly 
intended for astronomical purposes, we can hardly do with less 
than half the mirror open ; and on the other hand with a very 
narrow rim of reflection from the outside of the mirror, dis- 
tinctness would be apt to fail. 

£2^ Experiment. Trial of the Criterion on celestial Objects. 

I viewed a Lyrae with the outside rays, and found its spurious 
disk to be small ; with all the mirror open it was larger, and 
with the inside rays it was largest. 



of ascertaining the Magnitude of small celestial Bodies. 55 

As far as the imagination will enable us to compare objects 
we see in succession, the magnitudes appeared to be in an 
arithmetical progression. 

23^ Experiment. 

I examined et Geminorum' with 410,5, and with the outside 
rays the stars were considerably unequal, and 1^ diameter of 
the largest asunder. With all the mirror open they were 
more unequal, and i\ diameter of the largest. With the inside 
rays they were very unequal, and i\ of the largest asunder. 

These experiments show that, if it had not been known that 
the apparent disks of the stars were spurious, the application of 
the improved criterion of the apertures would have discovered 
them to be so ; and that consequently the same improvement 
IS perfectly applicable to celestial objects. 

observations on the nature and magnitude of mr. 
Harding's lately discovered star. 

It will be remembered that in a former Paper, where I 
investigated the nature of the two asterdds discovered by 
Signior Piazzi and Dr. Olbers, I suggested the probability 
that more of them would soon be foimd out ; it may therefore 
be easily supposed that I was not much surprised when I was 
informed of Mr. Harding's valuable discovery. 

On the day I received an account of it, which was the 24th of 
September, I directed my telescope to the calculated place of the 
new object,and noted all the smalLstars within a limited compass 
about it. They were then examined with a distinct high mag- 
nifying power ; and since no difference in their appearance was 
perceivable, it became necessary to attend to the chang^es that 



5(i Dr. Herschel's Experiments on the Means 

might happen in the situation of any one of therti- They were 
delineated as in Fig. i , ( Plate I. ) which is a mere eye-draught, 
to serve as an elucidation to a description given with it in the 
journal ; and the star marked k, as will be seen hereafter, was 
, the new object. 

Sept. $5. The moon was too bright to see minute objects 
well, and my description the night before, for the same reascHi, 
had not been sufficiently particular ; nor did I expect, from 
the account received, that the star had Retrograded ao far in 
its orbit. 

Sept. fi6. TTie weather being very hazy, no regular obser- 
vations could be made ; but as I noticed very particularly 
a star not seen before, it was marked / in Fig. », and proved 
afterwards to have been the lately discovered one, though still 
unknown this evening, for want of fuoed instruments. 

Sept. 27. I was favoured with Dr. Maskelyne's account of 
the place of the star, taken at the Royal Observatory, by which 
communication I soon found out the object I was looking for. 

Sept. 29. Being the first clear night, I began a regular series 
of observations ; emd as the power of determining small angles, 
and distinctness in showing minute disks, whether spurious or 
real, of the instrument I used on this occasion, has been suffi- 
ciently investigated by the foregoing experiments, there could 
be no difficulty in the observation, with resources that were 
then so well understood, and have now been so fully ascer- 
tained. 

" Mr. Harding's new celestial body precedes the very 
" small star in Fig. 3, between ag and 33 Pisclum, and is a 
" little larger than that star ; it is marked A. fgh are taken 
" from Fig. 1. I suppose ^ to be of about the 9th magnitude. 






of ascertaining the Magnitude of mail cekstial Bodies. 57 

** so that the new star may be called a small one of the 
**8th/' 

With the 10-feet reflector, power 496,3 , 1 viewed it atten- 
tively, and comparing it with g and A, Fig. 3, could find no 
dUFerenciBin the' appearance but what might be owing to its 
l»ing a larger star. 

By way of putting this to a trial, I changed the power to 
879,4^ but oxuld not find: diat dt magnified the new one more 
than it did the stirs g and h. 

" I. cjinnot perceive any disk; its apparent magnitude with 
this power is greater than that of the star g^ and also a very 
little greater than that of A; but in, the finder, and the night- 
'* glass g iis considerably smaller than the new star, dnd h is 
** also a very little smaller/' 

I compared it now with a star which in the finder appeared 
to be a very little larger ; and in the telescope with 879,4 the 
apparent magnitude of this star was also larger than that of 
the new one. 

" As far as I can judge without seeing the asteroids of Mr. 
" PiAzzi and Dr.OLBERs at the same time with Mr. Harding's, 
" the last must be at least as small as the smallest of the 
'-* forme!r, which is that of Dr. Olbers." 

" The star i&. Fig. 1, observed Sept. 24, is wanting, and was 
therefore the object I was in'search of, which by computation 
must have been thiat day in the place where I saw it." 
" The new star being now in the meridian with all those to 
" which I am comparing it, and the air at this altitude being 
" very clear, I still find appearances as before described : the 
V new object cannot be distinguished from the stars by mag- 
*^ nifying power, so that this celestial body is a true asteroid. " 

MDCCCV. I 






58 Dr. Hjsrschel's Experiments an the Means 

Mr. Bode's stars 19, 25 and 27 Ceti are marked 7m» and by 
comparing the asteroid, which I find is to be called Juno^ with 
these stars, it has the appearance of a small one of the 8th 
maghitude. 

. With regard to the diameter of Juno, which name it will at 
present be convenient to use, leaving it still to astronomers to 
adopt any oth6r they may fix upon, it is evident that, had it 
been half a second, I must have instantly perceived a visibli^ 
disk. Such a diameter, when I saw it magnified 879,4 times, 
would have appeared to me under an angle of 7' i9",7, bhe 
half of which, it will be allowed, from the experiments that 
have been detailed, could not have escaped my notice. 

Oct. 1 . Between flying clouds, I saw the asteroid, which in 
its true starry form has left the place where I saw it Sept. 89. 
It has taken the path in which by calculation I expected it 
would move. This ascertains that no mistake in the star was 
made when I observed it last. 

Oct. 2, 7^. Mr. Harding's asteroid is again removed, but 
is too low for high powers. 

8*^ 30'. I viewed it now with at 0,3 288,4 410,5 496,3 and 
879,4. ^^ other disk was visible than that spurious one whichr 
such small stars have, ^nd which is not proportionally mag* 
i)ified by power. 

With 288,4, ^^^ asteroid had a larger spurious disk than 
a star which was a little less bright, and a smaller spurious^ 
disk than another star that was a little more bright. 

Oct. 5, with 410,5. The situation qf the asteroid is now as 
in Fig. 4. I compared its disk, which is probably the spurious 
appearance of stars of that magnitude, with a larger, an equal; 
and a smaller star. It is less than the spurious disk of the 



oj ascertaining the Magnitude of small celestial Bodies. 59 

larger, equal to that of the equal, and larger than that of the 
smaller star. The gradual difference between the three stars 
is exceedingly small. 

'* With 490^3, and the 2ur uncwnmonly pure and calm, I see 

' • • • . 

** so well that I am certain the ^sk, if it be not a spurious one, 
" is less than one of the smallest globules I saw this morning 
«* in the tree." 

The diameter of this globule was ,02. It subtended an angle 
of o",429, and was of sealing-wax ; had it been a silver one, 
it would have been still more visible. 

With 879,4, All comparative magnitudes of the asteroid and 
stars, remain as with 496,3. 

I see the minute double star q Ophiuchi * in high perfection, 

» - >• . . 

which proves that the air is clear, and the telescope in good 
order. \- 

The asteroid being now in the meridian, and the air very 

pure, I think the comparative diameter is a little larger than 

« • 

that of an equal star, and its light also differs from star-light. 
Its apparent magnitude, however, can hardly be equal to that 
of the smallest globule I saw this morning. This globule 
measured ,01358, and at the distance of 9620,4 inches sub- 
tended! ah angle of o",2i4. 
When I viewed the asteroid with 879,4 I found more hazi- 

• * * 

ivt^^ than an equal star would have given : but this I ascribe 
to want of light. What I call an equal star, is one that in an 
achromatic finder appears of equal light. 

Oct. 7. Mr. Harding's asteroid has continued its retrograde 
motion. The weather is not clear enough to allow the use of 
high powers. 

• See Cat. of double Stars» I. %t. 

I2 



6o I^-. Heksckel's Experiments on^ijie Meatis / . 

Oct. 8. If die appearance resembling the .spurious 4^$k5 of 
small stars, which I see with 410,5 in Mr. Harding's asteroid, 
should be a real diameter, its quantity then by estimation njay 
amount to about o",3. This judgment is foun^led' on thc! fi^cility 
with which I can see two globules often view;efi foji^? this 
purpose. : \ r . i :■ ' 

The angle of the first is 0^,429, and of the other o",2i4 ; 
and the asterpid might be larger than the latter, but certainly 
was not equal to the former. 

With 496,3, there is an ill . defined hazy app^aranCQ, but 
nothing that may be called a disk visible. When therje, is a 
glimpse of more condensed light to>be>seen in the centre> it |s 
so small that it must, be less than twcKtenths of a second. 

To decide whether this apparent condensed light was a real- 
or spurious disk, I applied different limitations to the aperture 
of the telescope, but found that the light of thq new star was 
too feeble to permit di^ use of them. From this I concluded 
that an increase of light might now be of great use, and viewed 
the asteroid with a fine lo-feet mirror of 24 inches diameter; 
but found that nothing was gained by the change. The tem- 
perature indeed of these large mirrors is very seldom the 
same as that of the air in which they are to act, and till a 
perfect uniformity takes place, no high powers can be used. 
. The asteroid in the meridian, and the night beautiful. After 
many repeated comparisons of equal stars with the asteroid, I 
think it shows more of a disk than they do, but it is so small 
that it cannot amount to so much as 3-tenths of a second, or at 
least to no more. 

It is accompanied with rather more nebulosity than stars of 
tne same size. 



of ascertaining the Magnitude of smail celestial Bodies. 6 1 

The night iis so clear, that I cannot suppose vifeion at this 
altitude to be less perfect on the stars, than it is on day objects 
at the distance of 800 feet in a direction almost horizontal. 
r Oct. n. By comparing the asteroid alternately and often with 
equal stars, its disk, if it be a real orie, cannot exceed a, or at 
most s-tenths of a second. This estimation is founded on the 
comparative readiness with which every fine day I have seen 
globules subtending such angles in the same telescope, and 
with the samp magnifying power. 

^ The asteroid is in the meridian, and in high perfection. I 
" perceive a well defined disk that may amount to s or 3-tenths 
** of a second ; but an equal star shoWs exactly the same ap- 
'^ pearance, and has a disk as well defined and as large as that 
*' of the asteroid." 

RESULT AND APPLICAl ION OF THE EXPERIMENTS AND 

OBSERVATIONS. 

We may now proceed to draw a few very useful conclusions 
from the experiments that have been given, and apply them 
to the observations pf the star discovered by Mr. Harding ; 
and also to the similar stars pf Mr. Piazzi and Dr. Olbers. 
These kind of corollaries may be expressed as follows. 

( 1 . ) A lo-feet reflector will show the spurious or real disks, 
of celestial and terrestrial objects, when their diameter is ^ of 
a second of a degree ; and when every circumstance is fa- 
vourable, such a diameter may be perceived so distinctly, that 
it can be divided by estimation into two or three parts, 

( 2. ) A disk of ^ of a second in diameter, whether spurious 
or real, in order to be seen as a round, well defined body^ 



6s Dr. Herschel's Experiments on the Means 

requires a distinct magnifying power of 5 or 6 hundred, and 
must be sufficiently bright to bear that power. 

( 3. ) A real disk of half a second in diameter will become 
so much larger by the application of a mag^fying power of 5 
or 6 hundred, that it will be easily distinguished from an equal 
spurious one, the latter not being affected by power in the 
same proportion as the former. 

( 4. ) The different effects of the inside and outside rays 
of a mirror, with regard to the appearance of a disk, are a 
criterion that will show whether it is real or spurious, provided 
its diameter is more than ^ of a second. 

( 5. ) When disks, either spurious or r6al, are less than ^ of 
a second in diameter, they cannot be distinguished from each 
other ; because the magnifying power will not be sufficient to 
make them appear round and well defined. 

( 6. ) The same kind of experiments are applicable to tele- 
scopes of different sorts and sizes, but will give a different 
result for the quantity which has been stated at ^ of a second 
of a degree. This will be more when the instrument is less 
perfect, and less when it is more so. It will also differ even 
with the same instrument, according to the clearness of the 
air, the. condition, and adjustment of the mirrors, and the 
practical habits of the observer. 



With regard to Mr. Hardino's new starry celestial body, 
we have shown, by observation, that it resembles, in every 
respect, the two other lately discovered ones of Mr. PiAzzr 
and Dr. Olbers ; so that Ceres, Pallas, and Juno, are certainly 
three individuds of the same species. 



of ascertaining the Magnitiide of small celestial Bodies. 6^ 

That they are beyond comparison smaller than any of the 
seven planets cannot be questioned, when a telescope that will 
show a diameter of ^ of a second of a degree, leaves it unde- 
cided whether the disk we perceive is a real or a spurious 
on6. 

A distinct magnifying power, of more than 5 or 6 hundred, 
has been applied to Ceres, Pallas, and Juno, but has either left 
us in the dark, or at least has not fully removed every doubt 
upon this subject. 

The criterion of the apertures of the mirror, on account of 
the smallness of these objects, has been as little successful ; 
and every method we have tried has ended in proving their 
resemblance to small stars. 

It will appear, that when I used the name asteroid to denote 
the condition of Ceres and Pallas, the definition I then gave of 
this term * will equally express the nature of Juno, which, by 
its similar situation between Mars and Jupiter, as well as by 
the smallness of its disk, added to the considerable inclination 
and excentricity of its orbit, departs from the general condi- 
tion of planets. The propriety therefore of using the same 
appellation for the lately discovered celestial body cannot be 
doubted. 

Had Juno presented us with a link of a chain, uniting it to 
those great bodies, whose rank in the solar system I have also 
defined,'f by some approximation of a motion in the zodiac, 
or by a magnitude not very different from a planetary one, it 
might have been an inducement for us to suspend' our judgr 

* See Phil. Trans, for i8o2> p. 2tg, line lo. 
f Ibid, page 214* line 5 of the same Paper.. 



6^ Dr. Herschel's Experiments^ &c. 

ment with respect to a classification ; but the specific difference 
between planets and asteroids appears now by the addition of 
a third individual of the latter species to be more fully esta- 
blished, and that circumstance, in my opinion, has added more 
to the ornament of our system than the discovery of another 
planet could have done. 

Slougb» near Windsor, 
Pec. I, 1804. 



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C«5 3 



ML . An Essay on the Cohesion of Fluids. By Thomas Young, 

M. D. For. Sec. R. S. 



Read December so, 1804. 



I. General Principles. 

It has already been asserted, by Mr. Monge and others, that 
the phenomena of capillary tubes are referable to the cohesive 
attraction of the superficial particles only of the fluids em- 
ployed, and that the surfaces must consequently be formed 
into curves of the nature of lintearias, which are supposed to be 
the results of a uniform tension of a surface, resisting the 
pressure of a fluid, either uniform, or varying according to a 
given law. Segner, who appears to have been the first that 
maintained a similar opinion, has shown in what manner the 
principle may be deduced from the doctrine of attraction, but 
his demonstration is complicated, and not perfectly satisfactory ; 
and in applying the law to the forms of drops, he has neglected 
to consider the very material effects of the double curvature, 
which is evidently the cause of the want of a perfect coinci- 
dence of some of his experiments with his theory. Since the 
time of Segner, little has been done in investigating accurately 
and in detail the various consequences of the principle. 

It will perhaps be most agreeable to the experimental phi- 
losopher, although less consistent with the strict course of 
logical argument, to proceed in the first place to the comparison 

MDCCCV. K 



€6 I>. Young's Essay 

of this theory with the phenomena, and to inquire afterwards 
for its foundation in the ultimate properties of matter. But it is, 
necessary to premise one observation, which appears to be 
new, and which is equally consistent with theory and with 
experiment ; that is, that for each combination of a solid and a 
fluid, there is an appropriate angle of contact between the 
surfaces of the fluid, exposed to the air, and to the solid. This 
angle, for glass and water, and in all cases where a solid is 
perfectly wetted by a fluid, is evanescent : for glass and mer- 
cury, it is about 140"*, in common temperatures, and when the 
mercury is moderately clean. 

II. Form of the Surface of a Fluid. 

It is well known, and it results immediately from the com-- 
position of forces, that where a line is equably distended, the 
force that it exerts, in a direction perpendicular to its own, is 
directly as its curvature ; and die same is true of a surface of 
simple curvature; but where the curvature is double, each 
curvature has its appropriate effect, and the joint force must be 
as the sum of the curvatures in any two perpendicular direc- 
tions. For this sum is equal, whatever pair of perpendicular 
directions may be employed, as is easily shown by calculating 
the versed sines of two equal arcs taken at right angles in th^ 
surface. Now when the surface of a fluid is convex externally^ 
its tension is produced by the pressure of the particles of the 
fluid within it, arising from their own weight, or from that of 
the surrounding fluid ; but when the surface is concave, the 
tension is employed in counteracting the pressure of the at- 
mosphere, or, where the atmosphere is excluded, the equivalent 
pressure arising from the weight of the particles suspended 



on the Cohesion of fluids. 67 

from it by means of their cohesion, in the same manner as, 
when water is supported by the atmospheric pressure in an 
mverted vessel, the outside of the vessel sustains a hydrostatic 
pressure proportionate to the height ; and this pressure must 
remain unaltered, when the water, having been sufficiently 
boiled, is made to retain its situation for a certain time by its 
cohesion only, in an exhausted receiver. When, therefore, the 
surface of the fluid is terminated by two right lines, and has 
only a simple curvature, the curvature must be every where 
as the ordinate ; and where it has a double curvature, the sum 
of the curvatures in the different directions must be as the 
ordinate. In the first case, the curve may be constructed by 
approximation, if we divide the height at which it is either 
horizontal or vertical into a number of small portions, and 
taking the radius of each portion proportional to the reciprocal 
of the height of its middle point above or below the general 
surface of the fluid, go on to add portions of circles joining 
each other, until they have completed as much of the curve as 
is required. In the second case, it is only necessary to consider 
the curve derived from a circular basis, which is a solid of 
revolution ; and the centre of that circle of curvature, which is 
perpendicular to the section formed by a plane passing through 
the axis, is in the axis itself, consequently in the point where 
the normal of the curve intersects the axis : we must therefore 
here make the sum of this curvature, and that of the generating 
curve, always proportional to the ordinate. This may be done 
mechanically, by beginning at the vertex, where the two cur- 
vatures are equal, then, for each succeeding portion, finding 
the radius of curvature by deducting tlie proper reciprocal of 
die normal, at the beginning of the portion, from the ordinate, 

K2 



€8 Dr. Young's Essay 

and taking the reciprocal of the remainder. In this case the 
analysis leads to fluxional equations of the second order, which 
appear to afford no solution by means hitherto discovered; 
but the cases of simple curvature may be more easily subjected 
to calculation. 

III. Analysis of the simplest Forms. 

Supposing the curve to be described with an equable angulaf 
velocity, its fluxion, being directly as the radius of curvature, 
will be inversely as the ordinate, and the rectangle contained 
by the ordinate and the fluxion of the curve will be a constant 
quantity ; but this rectangle is to the fluxion of the area, as 
the radius to the cosine of the angle formed by the curve with 
the horizon ; and the fluxion of the area varying as the cosine, 
the area itself will vary as the sine of this angle, and will he 
equal to the rectangle contained by the initial ordinate, and the 
sine corresponding to each point of the curve in the initial circle 
of curvature. Hence it follows, first, that the whole area in-' 
eluded by the ordinates where the curve is vertical and where it is 
horizontal, is equal to the rectangle contained by the ordinate and 
the radius of curvature; and, secondly, that the area on the 
convex side of the curve, between the vertical tangent and the 
least ordinate, is equal to the whole area on the concave side 
of the curve between the same tangent and the greatest 
ordinate. 

In order to find the ordinate corresponding to a given 
angular direction, we must consider that the fluxion of the 
ordinate at the vertical part, is equal to the fluxion of the circle 
of curvature there, that, in other places, it varies as the radius 
of curvature and the sine of the angle formed with the horizon 



m the Cohesion of Fluids. 69. 

ronjointiiy, or as the ordinate inversely, and directly as the 
sine of elevation ; therefore the fluxion of the ordinate multi- 
plied by the ordinate is equal to the fluxion of any circle of 
curvature multiplied by its corresponding height, and by the 
sine, and divided by the radius : but the fluxion of the circle 
multiplied by the sine and divided by the radius, is equal to 
the fluxion of the versed sine ; therefore the ordinate multi- 
plied by its fluxion is equal to the initial height multiplied by 
the fluxion of the versed sine, in the corresponding circle of 
curvature ; and the square ofMie ordinate is equal to the rectangle 
contained by the initial height and twice the versed sine, increased by 
a constant quantity. Now at the highest point of the curve, the 
versed sine becomes equal to the diameter, and the square of 
the initial height to the rectangle contained by the initial height 
and twice the diameter, with the constant quantity : the con- 
stant quantity is therefore equal to the rectangle contained by 
the initial height and its difference from twice the diameter : 
this constant quantity is the square of the least ordinate, and the 
ordinate is every where a mean proportional between the greatest 
height and the same height diminished by txvice the versed sine of the 
angular depression in the corresponding circle of curvature. Again, 
at the vertical point, the square of the ordinate is equal to the square 
of the greatest height diminished by the rectangle contained by this 
height and the diameter of the corresponding circle of curvature, a 
rectangle which is constant for every fluid, and which may be 
called the appropriate rectangle : deducting this rectangle from the 
square of the ordinate at the vertical point, we have tJie least ordinate; 
which consequently vanishes when the square of the ordinate at 
the vertical point is equal to the appropriate rectangle; the horizontal 
surface becoming in this case an ^asymptote to the airve^ and the 



70 J>'. Young's Esiix^ 

square of the greatest ordinate being equal to twice the appropriate 
rectangle J and the greatest ordinate to twice the diameter of the tcr-^ 
responding circle of curvature: so that, if we suppose a circle to he 
described J having this- ordinate for a diameter, the chord cf like 
angular elevation in this circle will be always equal to the ordinate 
at each point, and the ordinate will vary as the sine of half the angle 
of elevation, whenever the curve has an asymptote, Mr. Fuss has 
demonstrated, in the third volume of the Acta Petropolitana^ 
some properties of the arch of equilibrium under the pressure 
of a fluid, which is the same as one species of the curves 
here considered. The series given by Euler in the second 
part of the same volume, for the elastic curve, may also be 
applied to these curves. 

IV. Application to the Elevation of particular Fluids. 

The simplest phenomena, which afford us data for deter- 
mining the fundamental properties of the superficial cohesion 
of fluids, are their elevation and depression between plates and 
in capillary tubes, and their adhesion to the surfaces of solids 
which are raised in a horizontal situation to a certain height 
above the general surface of the fluids. When the distance of 
a pair of plates, or the diameter of a tube, is very minute, the 
curvature may be considered as uniform, and the appropriate 
rectangle may readily be deduced from the elevation, recol- 
lecting that the curvature in a capillary tube is double, and the 
height therefore twice as great as between two plates. In the 
case of the elevation of a fluid in contact with a horizontal 
surface, the ordinate may be determined from the weight 
required to produce a separation ; and the appropriate rectangle 

* • 

may be found in this manner also, the angle of contact being 



an thi Ooiesiofi cf Fbdds. j% 

properly considered m this a$ well as m the fofmer case. It 
\viU appear that these experiments by no means exhibit; an 
immediate measure of the mutual attraction of the solid and 
fluids as some authors have supposed. 

Sir Isaac Newton asserts, in his Queries, that water ascends 
between two plates of glass at the distance of one hundjradth 
of an inch, to the height of about one inch ; the product of the 
distance and the height being about .01 ; but this appears to 
be much too little. In the best experiment of Mussch^kbroek, 
with a tube, half of the product was .0196; in several of 
Weitbrecht, apparently very accurate, .0214. In Monge's- 
experiments on plates, the product was 2.6 or s.7 lines, 
about .0210. Mr. Atwo6i> says that for tubes, the product is 
^058^> half of which is ^0265. Until more accurate experimmts 
shall have been made, we may be contented to assume .oa for 
the rectangle appropriate to water, and .04 for the product of 
the height in a tube by its bore. Hence, when the curve be-» 
comes infinite, is greatest ordinate is .», and the height of the 
vertical portion, or the height of ascent against a single ver^ 
tical plane .14, or nearly one-seventh of an inch* 

Now when a horizontal surface is raised from a vessel of 
water, the surface of the water is formed into a lintearia to 
which the solid is a tangent at its highest point, and if the 
solid be still further raised, the water will separate : the sur- 
face of the water, being horizontal at the point of contact,, 
cannot add to the weight tending to depress the solid, which 
is therefore simply the hydrostatic pressure of a column of 
water equal in height to the elevation, in this case one-fifth of 
an inch, and standing on the given surface. The weight 
of such a column will be 50^ grains for each sqjaare inch; and. 



7» Or. YoVfu^G^s Essay 

in Taylor^s well known eiperrraent the weight required wa$ 
go grains. But when the solid employed is small, the curva* 
ture of the horizontal section of the water, which is convex 
externally, will tend to counteract the vertical curvature, and 
to diminish the height of separation ; thus if a disc of an inch 
in diameter were employed, the curvature in this direction 
would perhaps be equivalent to the pressure of about oiie- 
hundredth of an inch, and might reduce the height from .2 to 
about .19, and the weight in the same proportion. ^ There is 
however as- great, a diversity in the results of different experi- 
ments on the fdrde required to elevate a solid frc«n the surface 
of a fluid; ^ in those of the experiments in capillary tubes : 
and indeed the sources of error appear to be here more 
numerous. Mr. Achard found that a disc bf gkss, 1 4- inch 
French in diameter, required, at ^9° of Fahrenheit, a weight of 
91 French grains to raise it from the surface of water ; this is 
of^V 37 English grains for each square inch ; at 4,4^^^ the force 
was y^g. greater, or 39^' grains', the diflference being -i-^. for 
each degree of Fahrenheit. It might be inferred from these 
experiments, that the hfeight of ascent in a tube of a given 
bore, which varies in the duplicate ratio of the height of ad- 
hesion,is diminished about j|^ for every degree of Fahrenheit 
that the temperature is raised above 56*; there was however 
probably some considerable source of error in Achard's ex- 
periments, for I find tliat this diminution does not exceed -j^^^. 
The experiments of Mr. DuTour make the quantity of water 
raised equal to 44. i grains for each square inch. Mr. Achard 
found the force of adhesion of sulfuric acid to glass, at 69'' of 
Fahrenheit, 1.26, that of water being 1, hence the height 
HV9S jas .69 to J, and its square as .47 to 1, which is the 



ontyiCgfmjm^^.Phitds. 73 

icorrespondihg proj>ortion far the ascent of, the. a^id' in ja/»pil- 

.iary tntie, .and which does Jiot. yery. mateffiaily diflfer fram Jh© 

^/jpoitipn of ^895 to ,i, assigned. tiyiBA«Av£L for tWs.AJcettt. 

3Mu^scii£Nop<BjD£K/fQVi^iit^ to .i,:but.his.a<:id wds.{xral>a|^ 

..weak. FQT.alcdibl the adhesion .was as t^figj.theJt^jght as 

•715^-^^d its square. as .^10 : the Qba^rYed.prppprtionin.at3j^, 

^acQoitding to .411 .experiment of Mu£(SCH£k&so£Ki Wi^s ^aiwUt 

' iS50f a(»:Qrding|[XQrCARB£' from 490 j to 440. /Th&eKperijntals 

.on sulfuric, ethercdo. not .agree jquite so well, but its^quati^iis 

liaUe to very icohsiderahle variations. jDutoujR found .the 

adhesion of alcohol .58, that of water being !• 

With respect, to merpuj^y, it .l)as ^cen , sho\yn by Professc^ 
Casbojs of Metz, afid jt|y others,„thatjjs, depression in tube* 
o£ glass depends on the. imperfjpction of the. contact, and that 
wjien it hasJbeen boiled in the ^ube often,enougl\tp expel .all 
foreign particles, the surface m^ even b€;.q9me coii9^ve instead 
of convex, and the depression be con vei^tfid .into an elevat;ion. 
But in barometers, ccm^tructed accordingjjqithe usuaLmethods, 
the angle of- the m^xairy willvjt;^& founds to differ 1 little f^om 
i/^d'-y andiiix>ther experiments, when pjrqper precautions ju:e 
taken, the inclination .will be nearly the :same. The detei^mi- 
natk)n of this angle is. necessaxyi for finding the;^ appropriate 
rectangle for the curvature of the surface of mercury, together 
with the observations ef the quantity of depression in tubes of 
a given diameter. The table published by^Mr. CAVENDisHfrom 
the experiments ef his father. Lord Charles Cavendish, ap- 
pears to be best suited for this purpose. I have constructed a 
diagram, according to the [Hrinciples already laid down,^for 
each case, and I find that the rectangle which agrees best with 
the phenomena is .oi. The mean depression is always .015, 

MDCCCV. L 



74 ^- YdUNG's Essay ^ 

divided by the diameter of the tube : and in tvbes less than 
half an inch in diameter, the curve is very nearly elliptic, and 
the central depression in the tube of a barometer may be found 
by deducting from the corresponding mean depression the 
square root of one-thousandth part of its diameter* There is 
reason to suspect a slight inaccuracy towards the middle of 
Lord Charles Cavendish's Table, from a comparison with the 
calculated mean depression, as well as from the results of the 
mechanical construction. The ellipsis approaching nearest to 
the curve may be determined by the solution of a biquadratic 
equation. 



Diameter 
in inches. 

* 


Gniot in 
an inch. 

c. 


Mean depres- 
sion by cal- 
cutation.Y« 


Central depres- 
sion by ob- 
servation, c. 


Central de- 
pression by 
formula. Y. 


Central de- 
presson by 
diagram. Y. 


Marginal de* 
pression by 
diagram. Y* 


.6 


d7« 


.025 


.005 


( -001 ) 


.005 


.066 


5 


675 


.030 


.007 


.008 


.007 


- .067 


•4 


43« 


.037 


.015 


.017 


.012 


.069 


•85 


331 


•043 


,o«5 


.024, 


.017 


.072 


'SO 


«43 


.050 


.036 


.033 


.027 


•079 


•»5 


169 


.060 


.050 


.044, 


.638 


.086 


.so 


108 


.075 


.067 


.061 


.056 


.096 


•'5 


61 


.100 


.' '^692. >' 


. ' .088 . 

• 


.085 


.116 


.lO 


a? 


.150 


.140 


.140 


.140 


.161 



The square root of the rectangle .oi, or ,1, is the ordinate 
where the curve would become vertical if it were continued ; 
but in order to find the height at which it adheres to a vertical 
surface^ we must diminish this ordinate in the proportion of the 
sine of 85"^ to the sine of 45^, and it will become .06, for the actual 
depression in this case. The elevation of the mercury that 
adheres to the lower horizontal surface pf a piece of glass, arid 



on the Cohesion of Fluids. 75 

« 

the thickness at which a quantity of mercury will stand when 
spread out cm glass^ supposing the angle of contact still 140*, 
are found, hy taking the proportion of the sines of ao° and of 
70' to the sine of 45**, and are therefore .0484 and -1330 
respectively. If, instead of glass, we employed any surface 
capable of being wetted by mercury, the height of elevation 
Would be .141, and this is the limit of the thickness of a wide 
surface of mercury supported by a substance wholly incapable 
of attracting it. Now the hydrostatic pressure of a column of 
mercury .0484 in thickness on a disc of one inch diameter 
would be 131 grains ; to this the surrounding elevation of the 
ilaid will add about 11 grains for each inch of the circum-- 
ference, with some deduction for tiiie effect of the contrary 
curvature of the horizontal section, tending to diminish the 
height; and the apparent cohesion thus exhibited will be 
about 160 grains, which is a little more than four times as great 
as the apparent cohesion of glass and water. With a disc 1 1 
lines in diameter Mr. Dutour found it 194 French grains, 
which is equivalent to 152 English grains, instead of 160, for 
an inch, a result which is suiBcient to confirm the principles of 
the calculation. The depth of a quantity of mercury standing 
on glass I have found by actual observation,- to agree precisely 
with this calculation. Segner says that the depth was .1358, 
both on glass and on paper : the difference is very trifling, but 
this measure is somewhat too great for glass, and too small 
for paper, since it appears from Dutour's experiments, that 
the attraction of paper to mercury is extremely weak. 

If a disc of a^ substance capable of being wetted by mercury, 
an inch in diameter, were raised from its surface in a position 
perfectly horizontal, the apparent cohesion should be 381 

L2 



7<S IV. Youi^G's Essay 

grains; taking' .141 as tft'e he:ght: and for a French circular 
mt\\\ 433' grains, or 528 French' grains; No^v, hi the experi- 
ments of MoRVEAU,'the cohesion of a circular inch of gold to 
the surface of mercury appeaffed to te 446 grains, of silvef 
429, of tin 418, of lead ^qj, 6f bFsmiith 372, of tmc 204, of 
Copper 142, df mettlllfc antimony 126, 6f ifoft 115, of cobfilt 
8 : iiiSi this order is the salme with that in which the ihetals 
&fe most Easily ariisflgamated ^ith mfercufy. It is probable? 
that sUth Sir amalgaftiatiori actuilly took place ih sonid of 
the e^tperiments, ^d dflfecterf their results, fdr the ptocess 
of amdlgaftiatlort may often be observed to begirt silttloM 
at the instant df corititt of silver '^♦ith inercui'y ; attd the 
want of perfect horizorttality appears in a shght degree to 
hkve afftcted them ail. A' deviation Of ohe-fiftifeth of ah inch 
would be suftibient to h^e produced tifie diffei^ehce between 
446 graihs and ^^ ; aiid it is not im'possiible iShAt all the dif- 
fei-erices, as far down ai bishiuth, rtidy hav^e b6fen acddentd. 
Biit if we iSiipifese the gbM only to have beert pferftctly wetted 
by the mercury, and all the oither ntifaibers tO bei ill du6 pHo- 
i)Ortiohs, we may find thte a^i^ojiWAte anglfe for each i&ubManfc^ 
by dediictShg from iS'o', ttWce t!hte ih^le <!>f which the ^6 is 
id the radiljrs is tfe apparent cAhe'sldri M e«ch «6 l^^ gr^Sris ; 
Ait is, M gold .r, fdr silver aft6ut .97, for Iftt -^s, m 4*a« 
.p6,Wt htsr^m is, fdr ziric .'4.^, for cop^ .^i.Tw %iflftridhy 
M^, fcA- Udh M6, 'arfd for Cobalt .bfi, Hegiedtrng tM A*- 
MAiding eTevafibn, 'whifc'h hiis less effect in pro'portibft ^"S «te 
surface eifii^loyed fs Ik¥ger! 'GELLifRT Tdwnd the afe-fS^^^ df 
ifteTted Ikaid m a tifbe df "gla^s iriultrpfi^d % iJie bdife 'fiq^id to 
abdtft ;6o5^. 
tt v(*ula perhaps be 'fibsSTble to piii^iue Afe^ pi'iriCipefe %ii 



071 the Cohesion of Fluids. 77 

fer as to determine in many cases the circumstances under 
which a drop of any fluid would detach itself from a giw^en 
sin^face. But it is sufficient to infer, from the law of the super- 
ficial cohesion of fluids, that the linear dimensions of similar 
drops depending from a horizontal surface must vary pre^* 
cisely in thfe same ratio as the heights of ascent of the re&pec^ 
live fluids against a vertical surface, or as the square root of 
the heights of ascent in a given tube : hence the magnitude 
of similar dtops of different fluids must vary as the cubes of 
the square roots of the heights of ascent in a tube. I have 
measured the heights of ascent of water and of diluted spirit 
of wine in the same tube, and I found them nearly as 100 to 64 : 
a drop of water falling fr<Mn a large sphere of glass weighed 
i.S grains, a drop of the spirit of wine about .Sg^ instead of 
.84, which is nearly the weight that would be inferred from 
the consideradota of the heights of ascent, comUned with that 
of tlte specific gravities. We may form a conjecture respecttfig 
the pfob^le magnHude of a drop by inqmring what must be 
tht chrumference of ^e fluid, that would support by its 
cohesion the weight of a hemisphere depending from it : this 
must be the same as fhsft of a tube, in which i&\e fl^iid would 
rise to llie haght of ^ne-^third of ite diameter ; and the <square 
of the 4»neter iHu^t be three tinies as great as the aippropriate 
Ifawhict; or, for wafter .12; whence the diameter twoudd be 
•^5> w a liMle more thai one-third of an inch, «nd the weight 
of Ihe henrisfphere would be 2.8 grains. If more w»t^ 'were 
added hltemally, the cohei^osi would be overcome, and the 
drop wouM no longer be suspended, bat it is not easy toxal^ 
c»Aate what precise quantity of water would be separated with 
it. The form of a bubUe of air rising in water is determined 



J 



yS Dr. Young's Essay 

by the cohesion of the internal surface of the water exactly in 
the same manner as the form of a drop of water in the air. 
The delay of a bubble of air at the bottom of a vessel appears 
to be occasioned by a deficiency of the pressure of the water 
between the air and the vessel ; it is nearly analogous to the 
experiment of making a piece of wood remain immersed in 
water, when perfectly in contact with the bottom of the vessel 
containing it. This experiment succeeds however far more 
f eadily with mercury, since the capillary cohesion^ of the mer- 
cury prevents its insinuating itself under the wood. 

V. Of apparent Attractions and Repulsions. 

The apparent attraction of two floating bodies, round both 
of which the fluid is raised by cohesive attraction, is produced 
by the excess of the atmospheric pressure on the remote sides 
of the solids above its pressure on their neighbouring sides: 
or, if the experiments are performed in a vacuum, by the eqi^-; 
valent hydrostatic pressure or suction derived from the weight 
and immediate cohesion of the intervening fluid. This force 
varies ultimately in the inverse ratio of the square of the dis^ 
tance ; for, if two plates approach each other, the height of 
the fluid that rises between them is increased in the, simple 
inverse ratio of the distance ; and the mean action, or negative 
pressure, of the fluid on each particle of the surface is also 
increased in the same ratio. When the floating bodies are both 
surrounded by a depression, the same law prevails, and \X9 
demonstration is still more simple and obvious. The repulsk>Q 
of a wet and a dry body does not appear to follow the same 
proportion: for it by no means apjH'oaches to infinity upoji 
the supposition of perfect contact ; its maximum is measured 



tn the Cohesion of Fluids. 79 

by half the sum of the elevation and depression on the remote 
sides of the substances, and as the distance increases, this 
maximum is only diminished by a quantity, which is initially 
as the square of the distance. The figures of the solids con- 
cerned modify also sometimes the law of attraction, so that, 
for bodies surrounded by a depression, there is sometimes a 
maximum, beyond which the force again diminishes : and it is 
hence that a light body floating on mercury, in a vessel little 
larger than itself, is held in a stable equilibrium without 
touching the sides. The reason of this will become apparent, 
when we examine the direction of the surface necessarily 
assumed by the mercury in order to preserve the appropriate 
angle of contact, the tension acting with less force when the 
surface attaches itself to the angular termination of the float 
in a direction less horizontal. 

The apparent attraction produced between solids by the 
interposition of a fluid does not depend on their being partially 
immersed in it ; on the contrary, its effects are still more power- 
fully exhibited in other situations ; and, when the cohesion 
between two solids is increased and extended by the interven- 
tion of a drop of water or of oil, the superficial cohesion of 
these fluids is fully sufficient to explain the additional effect. 
When wholly immersed in water, the cohesion between two 
pieces of glass is little or not at all greater than when dry : 
but if a small portion only of a fluid be interposed, the curved 
surface, that it exposes to the air, will evidently be capable of 
resisting as great a force as it would support from the pressure 
. of the column of fluid that it is capable of sustaining in a ver- 
tical situation ; and in order to apply this force, we must employ 
in the separation of the plates, as great a force as is equivalent 



{80 Dr. Young's Esiay 

to the ptessuve of -a column ^approprkte to their 
^MoRVEAU ifound rthat two discs of gk&s, .3 dnehes {French in 
^diameter, at the distance of one-^tenth of a line, af^ared flo 
Coheite with -a i force of 4,719 grains, . which is equt^coat tDjtiie 
tpressuf e of ta.'C€ilumn 93 lines in height: *. hence the prddiictof 
the^height ^and the distanceof the plates i5^;2.3 lines/ instead df 
^.65, whieh was the result of Monge's experiments on the 
actual ascent of \va*er. The dHFcrence' is much amailer ithfth 
the differettce of the .various /experiments on the ascent <Jf 
fluids ; and it may easily have arisen from a want of perfect 
paralleli:sm m the plates; for there is no force tendk^ to 
preserve' this* parallelism. The error, in the extrejjie case of 
the plates coming into contact at one point,, may reduce- the 
apparent cohesion to one half. 

The same theory is sufficient to explain the law of the force 
by which a drop is attracted towards the jxmction of two plates 
inclined ti>each other ^ and which isfound ta vary in thetinver^e 
ratio' of the squareof the distance ; whence it was < inferred by 
^Newton that the primitive force of cohefiion varies in the 
-^mple inverse ratio of the distance,, while other expenments 
lead us to suppose that cohesive forces in general, vary in the 
xiirect ratio of the . distance. But the difficulty is. remove by 
considering the state of the marginal surface of the.tftr^p. If 
the plates were parallel, the capillary action would be equal 
on both sides of the drop: but when they are inclined, the 
curvature of the suiface at the thinnest part reqijures- a fiai^oe 
proportionate to the appropriate height to counteract it ; afid 
this force is greater than that which acts on the opposite side. 
' But if the two plates are inclined to the horizon^ the deficiency 
may be made up by the hydrostatic weight of the. drop itself; 



} 



on the Cohesion of Fluids. 8 1 

and the same inclination wiW serve for a larger or a smaller 
drop at the same place. Now when the drop approaches to 
the line of contact, the drflference of the appropriate heights for 
a small drop of a given diameter will increase as the square of 
the distance decreases ; fo*r the fluxion of the reciprocal of any 
quantity varies inversely as the square of that quantity : and, 
in order to preserve the equilibrium, the sine of the angle of 
elevation of the two plates must be nealrly in the inverse ratio 
of the square of the distance of the drop from the line of 
contact, as it actually appears to have .been in Hauksbee's 
experiments, ^ 

• . ' ' , , - • • • 

« 

VI. Physical I^ndation ef the Law (f supeif^ 

We have now examined the principal phenomena which are 
reducible to the simple theory of the action of the superficial 
particles of a fluid. We are next to investigate the natural 
foundations upon which that theory appears ultimately to rest. 
We may suppose the particles of liquids, and probably those 
of solids also, to po^ssess that power of repulsion, which has 
been demonstratively shown by Newton to exist in aeriform 
fluids; aiid which varies^ ih the simple inverse ratio of the 
distance of the paH^lcles frt3*n each other. In airs and vapours 
this force appears to aCt uhfipntrolled ; but in liquids, it is over- 
come by cohesive force, while the particles still retain a power 
of moving freely in all directions; and in solids the same 
cohesion is accompanied by a stronger or weaker resistance to 
all lateral motion, which is perfectly independent of the co- 
hesive force, and which must be cautiously distinguished from 
it It is simplest to suppose the force of cohesion nearly or 
perfectly constant in its magnitude, throughout the minute 

MDCCCV. M 



I 



distance to vihich it extends^ and owing; its a^jj^rent diversslt}^ 
lp. the contrary acticm o£ the repulsive foree, which wiea^ 
with the distance. Nqw 19 t^e ifitemal: pafta oS ar ^qwd ti^ese 
forces hold each ot^her ip a perfect equilijimum, th^ pair^lea 
being brought soneaif tj^t the repulsion, becons^e^ precisely equ^I 
to the Gohf^sive fosce tba|; ^rges them, together : but whetjij^ver 
there isr a cujrv^d or angular sui:face,. it njay be found by coir 
Ijsctingdie actionSfOf the ^iffl^Tent p^rticj^s^ thaFt ^^ <K)he$t<:H> 
inv&t npce3i¥a|-ijy pi^vail oyer the i^epul.sionj,.and,inu«!turgQ the 
s^perSd^l f aytp ii>\v3rdsr with %. forijp propoirtionate to the 
curvature, and thus produce the effect of a uniform tenaiiaBiof 
the surface. For, if we consider the effect of any two particles 
in a. curved- line on* 9 third at> an equal dfstemce beyond them, 
w^ s^l iij^ ^i9A the result, of their eq^ajL aiMariictiyer foroes 
bl^ectei th^ angle. fonm^> by the Knes of dinectioD;; but that the 
result of tjh^ir ifep«l^iv€[ ^c)ei9,^oi)« of ivhicjfe ia twcs: as. great 
as, tbp othei^, 4f vi49$ ijt i» tfe^ r^^ of opfl t« two^ forjning with 
the U>Fimti ijepMlt m apgtei eqjial to* onp-siiKth: of the whole ; 
sp th^t th)^ a^tipQ Qf' % thi^rd; force i* necwsisaBy ul order to 
ret^n th^sft tVM>^^rei5^^ci?^.eqj)4iUbriW3if;. wA thfe:f«K»fiiM«st be 
ina|Consit»»tfrra^to the ev^^nesiqent aoglfirvsrfMBh-is th« raear 
sprfr of the Qi^rv^pre^ tfe^ dSjatfip^ of tfeft paitdckas betng 
con^ita^itf Th» saii^ rjijfisqiwng i^^y bp applied to aH the par*- 
tid^a which' aa?e :^i^yf\ thft iafkience of/ the- coheflive fiorcci: and: 
th(^ Qondusipps v^ eqUftHy^wft if ^ Qohosioni^jaot pnedflKly 

qon^ta^rtr b^t v^iiie^ Ief§ ^^gif^y tlmi» the ztcimlstoDi 

VII. Cahejsm Attraction of SQli4s. and Fluids. 

AYbfin) th^ a^^VM^oD) c^: ^ pairtic]efi< o£ a flukL for a solid is» 
les;^ tt^uH tHeic ^ittr/^on, fiw €t«[^ othen, tfame* vdl% be: an^ 



on Hu Qihmon tf Skids. 83 

tel|ifilftnu]lti <of tht supedniial .fdraen. If the surfiuce of tjhe fluid 
imdcfe With ^kM. icrif dae sodid a ^oertasn amgie, the versed ^te of 
wkieh is to the dkmefter^ as the mutual attraction of the fluid 
9kid solid partides is to the atbraibtion of die psrtacles of the 
fluid among teioh ol:her . Foir, when the fluid is surrounded by 
a vacuum or by n gas, the xx^hesion of its superficial pardcies 
acts with fuU force m producing a pressure ; but when it is 
any where in contact with a solid sub^nce of idire same 
attractive power With itself, the effects of this action must be as 
much defiStroJred as if it were ah internal portion of the fluid. 
Thus, if we imagined a cube of water to have one of its halves 
congealed, without any odier alteration c^ its properties^ it is 
eVideht that its form aind the equililniimi of tiie cohesive forces 
would Remain undistiurbed : die tendency of the new angular 
8Cirface of the fiutd water to contract would therefore be con^ 
jdeftely destroy^ by the oomact of a solid of equal attractive 
force. If the solid were of sriialkr dtfractive forck, the ten- 
dency to contract wouid only be propbrtioi:fflte to the diflerence 
of the attractive forces or densfttfes, the effect of as many of 
the athractiVe particles of lite fluid being neutralised, as ar& 
equivalent to a solid of a like density or attractive power. 
For a simikdr reason, the tendetvby of a fluid to contract the 
aum of the surfaces of itself aiad a contiguous solid, will be 
simply as tite detishy of the soKd, or as the mutual attractive 
f0rC:e of the scHid and fluid. And it is^ indifierent whether we 
consider the pressure produced by these suppoisec^ superficial 
tensions^ or fdte farce acdng in the direction of the surfaces 
to be compared. We may therefore inquire into the conditions 
of equilibrium of the three forces acting on the angular par- 
Ifdtes^ one in die direddon of the surfoce of the fluid only, a 



84 Dr. Young's Essay 

second in that of the commoa sbfEace of the solid and fluid, 
and tlie third in that of the exposed surface of the solid. Now, 
supposing the angle of the fluid to be obtuse, the whole super- 
ficial cohesion of the fluid being represented by the radius, the 
part which acts in the direction of the surface of the solid will 
be proportional to the cosine of the inclination ; and this force, 
added to the force of the solid, will be equal to the force of the 
common surface of the solid and fluid, or to the differences of 
their forces ; consequently, the cosine added to twice the force 
of the solid, will be equal to the whole force of the fluid, or to 
the radius : hence the forcie of the solid is represented by half 
the difference between the cosine and the radius, or by half the 
versed sine ; or, if the force of the fluid be represented by the 
diameter, the whole versed sine: will indicate the force of 
the solid. And the same result follows when the angle of the 
fluid is acute. Hence we ihay infer, that if the solid have half 
the attractive force of the fluid, the surfaces will be perpendi- 
cular ; and thiSiaeems in itself reiasonable, since two rectangular 
edges of the solid are* equally liear to die angular particles 
with one of the fluid, and we may expect a fluid to rise and 
adhere to the surface of every solid more than half as attractive 
as itself; a conclusion which Clairaut has already inferred, in 
a different manner, from principles wliich he has but cursorily 
investigated, in his treatise on the figiire of the earth. 

The versed sine varies as the square of the sine of half the 
angle : the force must therefore be as the square of the beirght 
to which the fluid may be elevated in contact with a horizontal 
surface, or nearly as the square of the niunber of grains ex* 
pressing the apparent cohesion. Thus, according to the expe- 
riments of MoRVEAU, on the suppositions already premised. 



'^ 



ofi the Cohesion of Fluids. ^5 

we may infer that the mutual attraction of the particles of 
mercury being unity, that of mercury for gold will be .1 or 
more, that of silver about .94, of tin .90, of lead .81, of bis- 
muth .73, of zinc .21, of copper .10, of antimony .08, of iron 
.07, and of cobalt .0004. The attraction of glass for mercury 
will be about one-sixth of the mutual attraction of the particles 
of mercury : but when the contact is perfect, it appears to be 
considerably greater. 

Although the whole of this reasoning on the attraction of 
solids is to be considered rather as an approximation than as a 
strict demonstration, yet we are amply justified in concluding, 
that all the phenomena of capillary action may be accurately 
explained and mathematically demonstrated from the general 
law of the equable tension of the surface of a fluid, together 
with the consideration of the angle of contact appropriate to 
every combination of a fluid with a solid. Some anomalies, 
noticed by Musschenbroek and others, respecting in particular 
the effects of tubes of considerable lengths, have not been 
considered : but there is great reason to isuppose that either 
the want of uniformity in the bore, or some similar inaccuracy, 
has been the cause of these irregularities, which have by no 
means been sufficiently confirmed to afford an objection to any 
theory. The principle, which has been laid down respecting 
^:he contractile powers of the common surface of a solid and a 
fluid, is confirmed by an observation which I have made on 
the small drops of oil which form themselves on water. There 
is no doubt but that this cohesion is in some measure inde- 
pendent of the chemical affinities of the substances concerned : 
tallow when solid has a very evident attraction for the water 



J 



^ Dr. Young's Essay 

out of which k is raised ; and the same attractioai Huxst ojperate 
upon an unctuous Hoid to cause it to i^ead on water, the 
fluidity of the wmter allowing this powerful agent to exert 
itself widi an wiresisted velocity. An oil which has thus 
been spread is afterwards ooUected, by some irr^uiarlty of 
ftttFftotiiw^ into thin drops, which the slightest agitation again 
dissipates: their surface forms a very regular curve, whic^i 
terminates abruptly in a surface perfectly horizontal : now it 
follows from the laws of hydrostatics, that the lower surface 
of these drops must constitute a curve, of which the extreme 
incIiDation to the horizon is to the inclination of the upper 
mrfftce as the specific gravity of the oil to the difierence be- 
tween its specific gravity and diat of water: consequently 
^ioce the contractile forces are held in equilibrium by a force 
which is perfectly horizontal, their magnitude must be in the 
ratio that has been already assigned ; and it may be assumed 
as ccaafsonant both to theory and to observation, that the am- 
tractile force of the common surface of two substances, is 
{MTOportional, other things being equal, to the difference of 
their densities. Hence, 4n order to explain the experiments 
g[ Boyle on the effects of a combination of fluids in capillary 
tubes, or any other experiments of a similar nature, we have 
only to apply the law of an equable tension, of which the 
magnitude is determined by the difference of the attractive 
powers of the fhiids. 

I shall reserve some further illustrations of this subject for 
a work which I have long been preparing fcH* the press, and 
which I flatter myself will contain a clear and simple exj^a- 
nation of th? most important puts of natural philosophy/. I 



on the Cohesion of Fluids. 87 

have only thought it right, in the present Paper, to lay before 
the Royal Society, in the shortest possible compass, the parti- 
culars of aa original investigation, tendiiig to explain some 
facts anid establish some analogies, which have hitheitQ been 
ohsciu^e and unintelligible. 



C88] 



IV. Concerning the State in which tlie true Sap of Trees is depo- 
sited during Winter. In a Letter jrom Thomas Andrew 
Knight, JE^g. to the Right Hon. ^S/r Joseph Banks, Bart. K. B. 
P.R.S. 



Read January 24, 1805. 

MY DEAR SIR, 

It is well known that the fluid, generally called the Sap in 
trees, ascends in the spring and summer from their roots, 
and that in thie autumn and winter it is not, in any considerable 
quantity, found in them; and I have observed in a former 
Paper, that this fluid rises wholly through the alburnum, or 
sap-wood. But Du Hamel and subsequent naturalists have 
proved, that trees contain another kind of sap, which they 
have called the true, or peculiar juice, or sap of the plant. 
Whence this fluid originates does not appear to have been 
agreed by naturalists ; but I have offered some facts to prove 
that it is generated by the leaf;* and that it differs from the 
common aqueous sap owing to changes it has undergone in its 
circulation through that organ : and I have contended that from 
this fluid (which Du Hamel has called the sue propre, and 
which I will call the true sap, ) the whole substance, which is 
annually added to the tree, is derived. I shall endeavour in 
the present Paper to prove that this fluid, in an inspissated 
state, or some concrete matter deposited by it, exists during 

• See Phil. Trans, of 180 1, page 336. 



Mr. Knight concertdng the State^ &xl 39 

tbe winter in the alburnum, an4 that from this fluic), pr $ul»- 
stance, dissolved in tlie ascending aqueous sap^ is deiriv^d the 
ma.tter which enters into the composition of tlp^ new leaves in 
the spring, and thus furnishes those organs, which were acA 
wanted during the winter, but which are essential to th^ 
further progress of vegetation. 

Few persons at ^U conversant with timber ve ignorant, that 
the alburnum, or sap-wood of trees, which are feUed in the 
autumn or winter, is much superior in quality to th^t of other 
t^es of the same species, which are suffered to stand till the 
spring, or summer : it is at once more firm and tenacious in 
its texture, and more durable. This superiority in winter- 
felled wood has been generally attributed to the absence of the 
£i^ at that season ; but the appearance and qualities of the 
v\rood seem more justly to warrant the conclusion, that some 
svibstapce has been added to, instead of taken frofti it, ^d 
many circumstances induced me to suspect that this substance 
is generated, and deposited within it, in the preceding summef" 

and autunm- 

Qy lj[ AMSJ. h^s remarked^ and is evidently puzzled with th^ 
fdr^ums^nce, that trees pq^;^pire more in the month pf August, 
)vhen ^ leaves ^re full growr^, and when the annual shoots 
have pea^d to elongate, than at any earlier period ; an^ w? 
cannot suppose the powers of vegetation to be thus actively 
eniplqyed, but in thp expputiqn of some very in[xportant oper^-r 
latipn. Bulbous and tuberous roots are almost whqlly generated 
fift^r the leaves and stems of the plants, to which they belong, 
h^y^ attained their full growth ; and I have constantly found, 
in my practice as a fanner, that the produce of my meadows has 
been imm«ns*ly increased when the herbage of the p;rejceding 

MDCCCV. N 



go Mr. Knight concerning the State in which 

year had remained to perform its proper office till the end of 
the autumn, on ground which had been mowed early in the 
summer. Whence I have been led to imagine, that the leaves, 
both of trees and herbaceous plants, are alike employed, during 
the latter part of the summer, in the preparation of matter 
calculated to afford food to the expanding buds and blossoms 
of the succeeding spring, and to enter into the composition of 
new organs of assiniilation. 

If the preceding hypothesis be well founded, we may expect 
to find that some change will gradually take place in the 
qualities df the aqueous sap of trees during its ascent in the 
spring ; and that any given portion of winter-felled wood will 
at the same time possess a greater degree of specific gravity, 
and yield a larger quantity of extractive matter, than the same 
quantity of wood which has been felled in the spring or in the 
early part of the summer. To ascertain these points I made 
the experiments, ah account of which I have now the honour 
to lay before you. 

As early in the last spring as the sap had risen in the syca- 
camore and birch, I made incisions into the trunks of those 
trees, some close to the ground, and others at the elevation of 
seven feet, and I readily obtained from each incision as much 
sap as I wanted. Ascertaining the specific gravity of the sap 
of each tree, obtained at the different elevations, I found that 
of the sap of the sycamore with very little variation, in dif- 
ferent trees, to be 1.004 when extracted close to the ground, 
and 1.008 at the height of seven feet. The sap of the birch 
was somewhat lighter ; but the increase of its specific gravity, 
at greater elevation, was comparatively the same. When ex- 
tracted near the ground the sap of both kinds was almost free 



tlie true Sap of Trees is deposited during WiMer. ^x 

from taste; but when obtained at a greater height, it was 
Sensibly sweet. The shortness of the trunks of the sycamore 
trees, which were the subjects of my experiments, did not 
permit me to extract the sap at a greater elevation than sewea 
feet, except in one instance, and in that, at twelve feet from 
the ground, I obtained a very sweet fluid, whose specific gra- 
vity w;as 1,01 a. 

I conceived it probable, that if the sap in the preceding cases 
derived any considerable portion of its increased specific gra- 
vity from matter previously existing in the alburnum, I should 
find some diminution of its weight, when it had continued to 
flow some days from the same incision, because the alburnum in 
the vicinity of that incision would, under such circumstances;, 
have become in some degree exhausted : and on comparing 
the specific gravity of the sap which had flowed from a recent 
and an old incision, I found that from the old to be reduced to 
i.oos, and that from the recent one to remain 1.004, ^^ ^^ the 
preceding cases, the incision being made close to the ground. 
Wherever extracted, whether close to the ground, or at some 
distance from it, the sap always appeared to contain a large 
portion of air. 

In the experiments to discover the variation in the specific 
gravity of the alburnum of trees at different seasons, some 
obstacles to the attainment of any very accurate results pre- 
sented themselves. The wood of different trees of the same 

* 

species, and growing in the same soil, or that taken from 
different parts of the same tree, possesses different degrees of 
solidity ; and the weight of every part of the alburnum ap- 
pears to increase with its age, the external layers being the 
lightest. The solidity of wood varies also with the greater or. 



^ ^r. Ksribttt cancemng the State in Tvhich 

less rkpiflky ttf its growth. These ^ou4*ces of ^r6r tnigHt ^^ 
parently have ^eWi avoided by ttrttiftg off, "at diljfeirerit seicsttos, 
pontons of lJr6 same trmrk or %rarich : btit tTie wormd thus 
taade might, fe some decree, haVe impeded fte Aie )prdgtess 
of 'the ^ap ?h its accent, aitd iJte part l)elow might have bedh 
m&Ae heavier %iy the sta^ation t)f the sap, tmd ifcft aflboSre 
Ughter by privation of its proper quantity of nutriment. The 
mcfet eligible ^method therefore, tvhich occurred te me, was to 
select and mark in the winter some ^f the poles of an oak 
cdppice, where all are of «qual age, and where miny, ^f the 
same Sizre and growing with equal vigour, spring fixym tlie 
same stool. 'One half of thepoles which I marked and num- 
bered were cuft on the gist of December, 1B05, and the 
remainder on the 15th of the foHo\s4ng May, when ^he leaves 
Xvere tteatly half grown. Proper marks wet'c put to'distinguish 
atie wimer-felled from the summer-felled poles, the bark being 
ieft on all, ahd ail being placed in the same situation to dry. 

In the beginning of August T cut off nearly equal portions 
from a winter and summer-felled pole, which had both grown 
on the same stool ; and both portions were then put in a 
situation, where, during the seven succeeding weeks, they 
were kept very warm by a fii'e. The sunlmer-felled wood was, 
when put to dry, the most heavy ; but it evidently contained 
much more water than the other, and, partly at least, from 
this cause, it contracted much more in drying. In the 'begin- 
ning of October both kinds appeared to be perfectly dry, and 
I then ascertained the specific gravity of the winter-felled 
wood to be 0.679, and that of the siimmer-felled wood to be 
0.609 ; after each had been immersed five minutes in water. 

This difference often per cent, was considerably more than 



fhe Hmt ^ap ^ -trees is ^imteU itim^- Writer, ^5 

I k^ m^i^&fB&A, and it wjis^tMf ^ft'^^pbtiSediaria MeA 
dlSrti^rti fl¥e Wa}a|iice «ajch p^ik^bn, at le^t t^ ^tifries, th^ 1 
(H^ased to %«ieve that some «rrdr had occurred m tite «xperi- 
iherit : arid indeed I was not at fest safSsfied tilH fead aseettamed 
feyraearis of compasses adapted to the measurefneift df ^dlids, 
that the winter-felled pieces of wood were much less than the 
dfters M4iich they ^uaHed in weight. 

The pieces of wood^ \vfaich had been the subj^dts of ^ese 

«■ 

Experiments, weri* agsSn put to dry, wiSi other pieces of the 

• '^ . . * * * ' * , 

ifai^e poles, and I 'yeJirtenlay ascertained ¥he ^specific gravity of 
boA wrth scarcely aAy Variation in the result. But when \ 
omitted the T^Atffla; ^tnd jiitrts adjitelfrt to it, and used the 
Isr^rers of woiid w^ch had'b^eh more recently fortned, Tfoimd 
the i^ecffic gravity of the wirfter-feTled wood to be CMily 0.583, 
artd thaft of the summer-felled to be 0.533 ; and trying the 
same experimertt with siiYiilar pieces of wood, 1)ut taken from 
poles which had grown on atirfferent stool, the specific gravity 
of the winter-felled wood was 0.588, and that of the suAimer- 
felled 0.534. 

It is evident that the whole of the preceding difference ill 
the specific gravity of lh6 winter and ^summer-fdled wood 
might have arisen from a greater degree bf contraction in the 
Former kind, "whilst drying ; 1 therefore proceeded to aScertaifi 
^vhether -a(ny given portion of it, "by weight, \vould aflbrd a 
greater quantity of extractive matter, when steeped in waiter. 
JHaving therefore reduced to small fragments 1 000 grains of 
each kind, I poured on each portion six ounces of boiling 
^vater ; and at the end of twenty-four hours, when the tem- 
J)erature of the water had sunk to 6o*, I found that the winter- 

< 

felled wood had communicated a much deeper colour to fhe 



94 Mr. Knight concerning the State in which 

water in which it had heen infused, and had raised its specific 
gravity to i.ooa. The specific gravity of the water in which 
the summer-felled wood had, in the same manner, been infused 
was i.ooi. The wood in all the preceding cases was taken 
from the upper parts of the poles, about eight feet from the 
ground. 

Having observed, in the preceding experiments^ that the sap 
of the sycamore became specifically lighter when it had con- 
tinued to flow during several days from the same Incision, I 
concluded that the alburnum in the vicinity of »ich indsion had 
been deprived of a larger portion of its concrete or inspissated 
sap than in other parts of the same tree : and 1 therefore sus- 
pected that I should find similar effects to have been producecjL 
by the young annual shoot? and leaves ; and that any gi ve^ 
weight of the alburnum in their vicinity would be found to coar 
tain less extractive matter than an equal portion taken from 
.the lower parts of the same pole, where no annual shoots or 
leaves had been produced^ 

No information could in this case be derived from the dif;^ 
ference in the specific gravity of the wood; because the sub- 
stance of every tree is most dense and solid in the lower parts 
of its trunk : and I could on this account judge only from the 
quantity of extractive matter which equal portions of the two 
kinds of wood would afford. Having therefore reduced to 
pieces several equal portions of wood taken from different 
parts of the same poles, which had been felled in May, L poured 
on each portion an eqyal quantity of boiling water, which. I 
suffered to remain twenty hours, as in the preceding experir 
ments : and I then found that in some instances the wood from 
the lQ>yer, and in others that from the upper parts of the poles^ 



the true Sap of Trees is deposited during Winter. ^5 

• r 

had given to the water the deepest colour and greatest degree 
of specific gravity ; but that all had afforded much extractive 
matter, though in every instance the quantity yielded was 
much less tfian I had, in all cases, found in similar infusions of 
winter-felled wood. 

• #■ 

It appears, therefore, that the reservoir of matteir deposited 
in the alburnum is not wholly exhausted in the succeeding 
spring : and hence we are able to account for the several suc- 
cessions of leaves and biids which trees are capable of producing 
when those previously protruded have. been destroyed by 
insects, or other causes ; and for the extremely luxuriant 
shoots, which often spring from the trunks of trees, whose 
branches have been long in a state, of decay. 

I have also some reasons to believe that the matter deposited 
in the alburnum remains unemployed in some cases during 
several successive years : it does not appear probable that it 
can be all employed by trees which, after having been trans- 
planted, produce very few leaves, or by those which produce 
neither blossoms nor fruit. In making experiments in 1802, 
to ascertain the manner in which the buds of trees are repro-^ 
duced, I cut off in the winter all the branches of a very larg^ 
old pear-tree, at a small distance from the trunk ;^ and I pared 
off, at the same time, the whole of the lifeless external bark. 
The age of this tree, I have good reasons to believe, somewhat 
exceeded two centuries : its extremities were generally dead ; 
and it afforded few leaves, and no friiit ; and I had long ex- 
pected every successive year to terminate its existence. After 
being deprived of its external bark, and of all its buds, no 
marks of vegetation appeared in the succeeding spring, or 
early part of the summer: but in the beginning of July 



gl$ Mr. BCnigbt concerning the $t^te, m wlwh 

numerous buds penetrated through the bark in. ?very part^ 
many leaves of large size every where appeared, and i^ thje 
autumn every part was covered with very vigoroys &Ik>^ 
exceedinga^ in the aggregate, two feet ip lengthy The mflnb^ 
of leaves which, in this case, sprang at once from the. triyil^ 
and branches* ajppe^red to me gif^^y to exceed the whole of 
those, which the tre^ had born in the three preoec^ng seasons \ 
apd I cannot believe that the matter wluch co^nppsed ^^es^ 
buds and leaver could have be^n» whoUy PT^^af^ by^th^ feeUl^ 
vegetatix)n and scai^y ipl^g^ S^ ^!^ pr«cediqg year. 

But whether the substance whi^h is ioitf^d in the alburnuQl 
of winter-felled trees, a^d which cbsappears in part ii^ t^i^ 
spring and early part of the summer, b^ genera^^ in o^ <ff 
m several preceding years^ t^^ere seem to be strong grpuBds 
of probability, that tlfis substance enters into the composition 
C(f t][\f kf^f : for we have ^bundqnt reason to believe that tl;i§ 
organ is the principal agent of assimilation ; and scarcely ai\y 
iiu^g ca^i be morecontr^y to every conclusion we shp^ld 
<|r^w from analogic^ reas9l\inga|nd coxQpafis9n of the vegetable 
with the ^imal ecppomy , or in itself more improbable, th^ 
that the Leaf^ or apy other organ, sl^ould singly pi*epare an4 
|issi»^k^^ immediately fxf^ ^he crudi^ aqueous sap, that matter 
^liich composes itself^. . 

It has been contended^ that the buds themselves cont^ip 
the qytriment necessary for tl^e minute unfolding leaves : but 
tre^s possess a power to fepro4u^ their buds, ^nd the ma^t^F 
necessary to form these buds must evidently be dierived froiii 
som^ other source : nor do^s it appjear probable that the yoi^ng 
leaves y^y soo^ ei^ter on this office : for the experiments o£ 



the true Sap of Trees is deposited during Winter. 97 

Ingekhouz prove that their action on the air which surrounds 
them is very essentially different from that of full grown 
leaves. It is true that buds in many instances will vegetate, 
and produce trees, when a very small portion only of albur- 
num remains attached to them ; but the first efforts of vege- 
tation in such buds are much more feeble than in others to 
which a larger quantity of alburnum is attached, and therefore 
we have, in this case, no grounds to suppose that the leaves 
derive their first nutriment from the crude sap. 

It is also generally admitted, from the experiments of 
Bonnet and Du Hamel, which I have repeated with the same 
result, that in the cotyledons of the seed is deposited a quantity 
of nutriment for the bud, which every seed contains ; and 
though no vessels can be traced* which lead immediately 
from the cotyledons to the bud or plumula, it is not difficult to 
point .out a more circuitous passage, which is perfectly similar 
to that through which I conceive the sap to be carried from the 
leaves to the buds, in the subsequent growth of the tree ; and 
I am in possession of many facts to prove that seedling trees, 
in the first stage of their existence, depend entirely on the 
nutriment afforded by the cotyledons; and that they are 
greatly injured, and in many instances killed, by being put to 
vegetate in rich mould. 

We have much more decisive evidence that bulbous and 
tuberous rooted plants contain the matter within themselves 
which subsequently composes their leaves ; for we see them 
vegetate even in dry rooms, on the approach of spring ; and 
many bulbous rooted plants produce their leaves and flowers 
with nearly the same vigour by the application of water only, 

♦ Hedwig. 
MDCCCV. O 



g8 Mr. ICNiGHt concerning the State in which 

as they do when growing m tJie *best mould. But the water m 
this case, provided that it be perfectly pure, prdb&bly af?brds 
Ktde or no food to the plant, and acts only by ^tfssolving the 

matter prepared and deposited in the preceding year; and hence 

• __ 

the root becomes exhausted and -spoiled: and HASStNttiATzTound 
that the leaves and flowers and roots of strch ^plants affi!*dfed no 

• • • . 

more carbon than he had proved to exist inlnilbous jrootis of <he 
same weight, whose leaves and flowers Tiad never expanded. 

As the leaves and flowers of the hyadnth, in the preceding 
case, derived their matter from the bulb, it appears extremely 
probable that the blossoms of trees receive fteir nutriment firom 
the alburnum, particularly as the blossoms of many spedes 
precede their leaves : and, as the roots of plants become weak- 
ened and apparently exhausted, when they have aflbtded mttri- 
ment to a crop of seed, we may suspect that a tree, which has 
borne much fruit in one season, becomes in a similar way 
exhausted, and incapa^ble of affording proper nutriment to a crop 
in the succeeding year. And I am much inclined to befieve that 
were the wood of a tree in this state accurately weighed, it 
would be found specifically lighter than that of a similar tree, 
which had not afForded nutriment to fnut or blossoms, in the 
preceding year, or years. 

If it be admitted that the substance which enters into the 
composition of the first leaves in the spring is derived from 
matter which has imdei^one some previous preparation within 
the plant, ( and I am at a loss to conceive on what grounds this 
can be denied, in bulbous and tuberous rooted plants at least, ) 
it must also be admitted that the leaves which are generated in 
the summer derive their substance from a similar source ; and 
this cannot be conceded without a direct adnnssion of the 



the true S^ of Trees is deposited during Winter. 99 

existence of vegetable circulation, which is denied by so many 
eminent naturalists. I have not, however, found in their writings 
a single fact to disprove its existence, nor any great weight in 
thdr arguments, except those drawn from two important errors 
in the admirable works of Hales and Du Hamel, which I have 
noticed in a former memoir. I shall therefore proceed to point 
out the channels^ through which I conceive the circulating fluids 
to pass. 

When a aeed is deposited in the ground, or otherwise exposed 
to a proper degree of heat and moisture, and exposure to air, 
water is absorbed by the cotyledons and the young radicle or 
root is emitted. At this period, and in every subsequent stage 
of the growth of the root, it increases in length by the addition 
of new parts to its apex, or point, and not by any general dis- 
tension of its vessels and fibres ; and the experiments of Bonnet 
and Du Hamel leave little grounds of doubt^ but that the new 
matter which is added to the point of the root descends from the 
cotyledons. The first motion therefore of the fluids in plants is 
downwards, towards the point of the root; and the vessels 
which appear to carry them, are of the same kind with those 
which are subsequently found in the bark, where I have, on a 
former occasion, endeavoured to prove that they execute the 
same oflice. 

In the last spring I examined almost every day the progressive 
changes which take place in the radicle emitted by the horse ches- 
nut : I found it, at its first existence, and until it was some weeks 
old, to be incapable of absorbing coloured infusions, when its 
point was taken off, and i was totally unable to discover any 
albumous tubes, through which the sap absorbed from the 
ground, in the subsequent growth of the tree, ascends: but 

Os 



I 



100 Mr. Knight concerning the State in which 

when the roots were considerably elongated, albumous tubes 
formed; and as soon as they had acquired some degree of 
firmness in their consistence, they appeared to enter on their 
office of carr)ing up the aqueous sap, and the leaves of the 
plumula then, and not sooner, expanded. 

The leaf contains at least three kinds of tubes : the first is 
what, in a fonner Paper, I have called the central vessel, through 
which the aqueous sap appears to be carried, and through which 
coloured infusions readily pass, from the albumous tubes into 
the leaf-stalk. These vessels are always accompanied by spiral 
tubes, which do not appear to carry any liquid: but there is 
another vessel which appears to take its origin from the leaf, 
and which descends down the internal bark, and contains the 
true or prepared sap. When the leaf has attained its proper 
growth, it seems to perform precisely the office of the cotyledon; 
but being exposed to the air, and without the same means to 
acqirire, or the* substance to retain moisture, it is fed by the al- 
bumous tubes and central vessels. The true sap now appears to 
be discharged from the leaf, as it was previously from the cotyle- 
don, into the vessels of the bark, and to be employed in the for- 
mation of new albumous tubes between the base of the leaf and 
the root. From these alburnous tubes springother central Vessels 
and spiral tubes, which enter into and possibly ^ve existence to> 
other leaves ; and thus by a repetition of the same process the 
young tree or annual shoot continues to acquire new parts, 
which apparendy are formed from the ascending aqueous sap; 

But it has been proved by Du Hamel that a fluid, similar to 
that which is found in the true sap vessels of the bark, exists 
also in the alburnum, and this fluid is extremely obvious in the 
fig, and other trees, whose true sap is white, or coloured. The 



the true Sap of Trees is deposited during Winter. loi 

vessels, which contain this fluid in the albumuni, are in contact 
ivith those which carry up the aqueous sap ; and it does not 
appear probable that, in a body so porous as wood, fluids so 
near each other should remmn wholly unmixed. I must there- 
fore conclude that when the true sap has been delivered from 
the cotyledon or leaf into the returning, or true sap vessels of 
the bark, one portion of it secretes through the external cellular, 
or more probably ^ndidar substance of the bark, and gene- 
rates a new epidermis, where that is to be formed ; and that 
the other portion of it secretes through the internal glandular 
substance of the bark, where one part of it produces the new 
layer of wood, and the remainder enters the pores of the wood 
already formed, and subsequently mingles with the ascending 
aqueous sap; which thus becomes capable of affording the 
matter necessary to form new buds and leaves. 

It has been proved in the preceding experiments on the 
ascending sap of the sycamore and birch, that that fluid does 
not approach the buds and unfolding leaves in the spring, in the 
state in which it is absorbed from the earth : and therefore we 
may conclude that the fluid, which enters into; and circulates 
through the leaves of plants, as the blood through the lungs of 
animals, consists of a mixture of the true sap or blood of the 
plant with matter more recently absorbed, and less perfectly 
assimilated. 

It appears probable that the true sap undergoes a considerable 
change on its mixture with the ascending aqueous sap ; for tliis 
fluid in the sycamore has been proved to become more sensibly 
sweet in its progress from the roots in the spring, and the liquid 
which flows from the wounded bark of the same tree is also 
sweet ; buti have never been able to detect the slightest degree of 



iosl Mr. Knight concerning the State in xiuhich 

sweetness in decoctions of the sycamoire wood in winter. I am 
therefore inclined to believe that the saccharine matter existing 
in the ascending sap is not immediately, or wholly, derived 
from the fliiid which had circulated through the leaf in the 
preceding year ; but that it is generated by a process similar to 
that of the germination of seeds, and tiiat the same process is 
always going forward during the spring and summer, as long 
as the tree continues to generate new corgans. But towards the. 
conclusion of the summer I conceive that the true sap simply 
accumulates in the alburnum, and thus adds to the spedfic 
gravity of winter*felled wood^ and increases the quantity of its 
extractive matter. 

I have some reasons to beUeve that the true sap descends 
through the alburnum as well as through the bark, and I have 
been informed that if the bark be taken from the trunks of trees 
in the spring, and such trees be suffered to grow till the fol- 
lowing winter^ the alburnum acquires a great degree of 
hardness and durability. If subsequent experiments prove that 
the true sap descends through the alburnum, it will be easy to 
point out the cause why trees continue to vegetate after all 
communication between the leaves and roots, through the bark, 
has been intercepted : and why some portion of alburnous 
matter is in all trees^ generated below indsions through the 
bark. 

It was my intention this year to have troubled you widi some 
observatioiis on the reproduction of the buds and roots of trees ; 

* I have in a former paper stated that the perpendicular shoots of the vine form an 
exception. I spoke on the authority of numerous experiments ; hut they had been 
made late in the summer ; and on repeating the same experiments at an earlier period, 
1 found the result »n conformity with my experiments on other trees. 



the true Sap of Trees ti ^deposited during fVinter, 103 

btit as the subject of the Paper, which I have now the honour 
to address to you, appeared to be of more importance, I have 
deferred tho$e observatione to af^tuFe^0|>portu)^jty ; and |.shaU 
at present oiilyK)b^efve, .that Idtonq^ve^nyselft^ beiii jpossessbn 
of facts to prove diat both buds' and roots originate from the 
albumous substance of plants, and not, as is, I believe, generally 
supposed, from the .liafk. i . i 



• 1 • 

£lton« Dec. 4, 






I am, &c. 

T, ANPRE W KNIGHT. . 



i A 



• . : 



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< f. 



( ■ • 



i,. . 



C 1043 






_ _ 4 , 

V. On the Action of Platina and Mercury upon each other. By 
Richard Chenevix, Esq. F. R. S. M. R.I.A. &c. 



Read January 10, 180^. 

Frqrberg, June 3d, 1804* 

On the 12th of May, 1803, 1 had the honour of presenting a 
Paper to the Royal Society, the object of which was to discover 
the nature of palladium, a substance just then announced to 
the public as a new simple metal. The experiments which I 
had made for this purpose led me to conclude that palladium 
was not what it had been stated to be, but that it was a com- 
pound of platina and mercury. 

It was natural to suppose that a subject so likely to spread 
its influence throughout the whole domain of chemistry, and 
which tended even to the subversion of some of its elements, 
would awaken the attention of philosophers. We find accord- 
ingly, that it has become a subject of enquiry in England, 
France, and Germany ; but the experiments which I had re- 
commended as the least likely to fail, have been found insuf- 
ficient to insure the principal result ; and I have had the 
mortification to learn that they have been generally unsuc- 
cessful. I have even reason to believe that the nature of 
palladium is still considered by chemists, at least with a very 
few exceptions, as unascertained; and that the fixation of 
mercury by platina is by many regarded as visionary. 

The first doubts were manifested in England; and Dr. 



Mr. Chenevix on the Action^ &c. 105 

WoLLAanroN very early deiied the accuracy of my inquiries. 
But as he has not published his experiments, I have had no 
opportimity of discussing them. His opinion, however, must 
have such weight in the learned world, that I should have 
neglected a material fact in the history of palladium, if I had 
not mentioned it in this place. 

In France the compound nature of palladium has been more 
generally credited. When the National Institute was informed 
of my experiments, a report was ordered to be made upon 
them, and M. Guyton was the person appointed for the 
purpose. He repeated some of the experiments, and produced 
«ome of his results. His general conclusion was the same as 
mine. 

Messrs. Vauquelik and Fourcroy then undertook the 
subject, • and they were led by it to the confirmation of the 
recent discovery of Mons. Descotils. The existence of a 
new metal, which that chemist had found in crude platina, 
received gr^at sanction from their experiments ; and thus the 
discussion \xpon palladimn has established a fact which will be 
considered as interesting, but which would be much more so, 
were we not already overburthened with substances which our 
present ignorance obliges us to acknowledge as simple. 

No sooner were these celebrated chemists convinced of the 
existence of a new metal in platina, than they concluded that 
it must play a prindpal part in the composition of palladium. 
Shordy after this, in a note to a letter from M.' Proust to M. 
Vauquelin, in which M. Proust expresses his astonishment 
concerning all he has read upon palladium, Mess. Fourcroy 
and Vauquelin further declare, as their opinion, that this com- 
pound metal does not contain mercury, but is formed of platina 

MDCCCV. P 



xo6 Mr. Chenevix on the Action of 

and the new metal. Whether this new substance does or does 
not play a principal part in the formation of palladium/ could 
not be ascertained at the time my experiments were made, 
because the new metal itself was not then known. But from 
all that Mess. Fourcroy and VAUgftJELiN have stated, in such of 
their different memoirs upon this subject as I have seen, the 
grounds of their supposition have not appeared. May we. not 
refer their opinion, then, to that Common propensity of the 
mind, against which M. FourCroy has himself warned us 
with equal justness and eloquence 0(1 another occasion, namely, 
a proneness to be allured by novelty Beyond the bounds of 
rational belief, and to convert prindples which are new into 
principles of universal influence. 

Mess. Rose* artd Gehlen ♦ were the first among the German 
chemists who instituted experiments upon palladium ; and M. 
RicHTER has also published a paper on the same subject. 

The first attempt oi Mess. Rose and Gehle)) to form pal- 
ladium was by the precipitation of a mixed solution of platina 
and mercury by green sulphate Of iron. Their result waspr^ 
cisely that which I had observed when my operations failed 
altogether, and which of course was the most frequent This 
^method was repeated twice. The second time the precipitate 
of platina and mercury was boiled with muriatic add, in order 
to free it from iron; but the latter trial was not more: succeM- 
ful than the former. 

Their third experiment was, what they have callM, a repe- 
tition of that in which I had obtained palladium bypassing a 

* Neucs Algimtines Journal dir Cbemie beramsgegeben vau Htrmstadi, 
Klaprotr, RicMTBR, ScQERER, TromsdorFs und Gbhlbm. Ersten banits 
fnnfles bijt. 



Platina arid Meromy upon each other. 107 

current of dulphuretfed hydrogen ga$ through a mixed solution 
of platina arid mercury. Their mbtiiiod Ivfts the following^ 
They diss6lyed one hundred and fifty grains of platina with 
four hundred and fifty of mercury., and added a solution of 
hydrosulphuret of potash. They obtfiined a precipitate which, 
at first, was'blauck, afterwards ^ gray ; but the whole became 
black by being stirred. To be ce^tajin that all the metal was 
precipitated, they addied an excess of sulphuret of potash, and 
perci^ii^ed that a part i of' the precipitate was redissolyed. The 
liquor was then filtered, and to that part of it, which contained 
the redissolved ]iredpita&, 4a acid was added; From this pro- 
cess they obtained, a. yellow precipitate weighing ninety-one 
grains ; ^dfifty^ ^ains of this, exposed tO;a strong heat, left 
tiireei^ghths of !a gr^ of;pjlatii).a. They obtained no palla^ 
dium from that part df^the fa:eci|>itate which had not been 
redissc^ved ; and the result of th^ experiment was complete 
foilure; .. : i . 

r dhadUi . no): make any obsery^ticm upon the issue of this 
inrocess, since^ i^iUus caite; theb^st cogtidufled. i^ bnt^ too liable 
to be unaiccessfbl^ and that without any ai^arent fault in the 
opc9ra|br:. But as it has b^en gplvjen as a rep^titicm of one of 
mine, it may riot be fruftLess to examitie hovr far the repetition 
waS' exact. . . : • .L . 

I had passed a current of sulphuretted hydrogen gas through 
a mire^ jsolution of pdatina and mei^cury , by which means they 
were preajHtatfed together. .My QJ^je^t was so intimately to 
combine sulphur with these metals, that when exposed to heat^ 
they might (if I may be allowed the expre^ion ) be in chemical 
contact with It at the mom^t of their nascent metallic state ; 
and as a iovf temperijtiure! sUiSSces, as well to reduce those 

Pa 



I 



ic8 Mr. Chenevix Ofi the Action of 

metals, as to combine palladium with sulphur, I hoped that 
those efiects might be produced before the total dissipation of 
the mercury. How far my expectation was fulfilled has been 
stated in my former Paper. 

The sulphuretted hydrogen gas which Mess. Rose and 
Gehlen presented to thoise metals was combined with potash. 
Now, in the course of dodmastic lectures annually delivered by 
M. Vauquelin at the Ecole des Mines in Paris, when he wius 
Professor at that establishment, it was his constant custxnn to 
exhibit an experiment to prove that mercury, predpitated from 
its solution by many of the alkaline and earthy hydrosulphurets^ 
was redissolved by adding an excess of them. 

It is moreover well known, that there is a strong affinity 
between potash and the oxide of platina, and also that when 
those substances are brought together in tolatsm, a triple salty 
but little soluble, is the result. It was to avoid these difficulties, 
that I had employed uncombined sulphuretted hydrogen gas; for 
the method adopted by Mess. Rose and Gehlen apt>earing to me 
to be the application of two divellent forces, I presumed that it 
would produce a separation. The result of their experiment^ 
which, it appears from their paper, they had.not anticipated^ 
shews the necessity of the precaution I had used. The opera* 
tion which they performed to unite platina and mercury waa, 
in fact, nearly the reverse of that which they supposed they 
had repeated from me, and might have been ap)^ed perhaps 
with a better prospect of success towards the decomposition of 
palladium. 

Mess. Rose and Gehlen seem, in many parts of their paper, 
to question my having fused platina; and inform us that 
although they had exposed this metal in the furnace of , the 



Ptatina and Mercury upon each other. 109 

Royal'Porcelain Manufactory of Berlin, in which Wedgewood's 
pyrometer ceased to mark the degree of heat, they could not 
accomplish its fusion. Many of my friends in England have 
however seen the buttons which I obtained, and which were 
not few in number. The flux which I had used was borax. 
But no mention is made in any one of the operations of Mess* 
Rose and Gehlen of borax having been employed. 

In many of their attempts they obtained an irregular and 
porous mass, which of course was of a specific gravity much in- 
ferior to that of platina ; and it might be inferred from their paper 
that the diminution of specific gravity, which I had observed, 
was owing to the same cause. It is true, not only that I had 
very often obtained such a mass, but that I had frequently also 
observed no diminution whatsoever in the specific gravity of 
the button which resulted from my operations. But all those 
upon which I had founded the conclusions alluded to by Mess. 
Rose and Gehlen were performed in the following manner, 
and have been repeated since. A Hessian crucible was filled 
with lamp-black, and the contents pressed hard together. The 
lamp-black was then hollowed out to the shape of the crucible 
as far as one^third from the bottom, leaving that much filled 
with the compressed materials ; this lining, which adhered 
strongly to the sides of the crucible, was made extremely thin 
in order not to obstruct the passage of caloric. A cylindrical 
piece of wood, as a pencil, was then forced into the centre of 
the thick mass of lamp-black at the bottom, and the diameter 
of this rod was determined by the quantity of metal to be 
fused, or varied according to other circumstances at pleasure. 
In general the axis of the cylindrical hole was about three or 
four times the diameter of the basis. After withdrawing the 



no Mr. Chenevix on the Action of 

tod the crucible was about half filled with borax. Upon thu^ 
was placed the metal to be fused ; and if it had been before 
melted into a cylindrical form, the axis of the metallic cylinder 
was placed horizontally, and was of course perpendicular to 
the axis of the cylindrical excavation at the bottom of the 
crucible. More borax was then added to cover the piece of 
metal, and another quantity of lamp-black was pressed hard 
over the whole in order to keep it tight together. An earthen 
cover was finally luted to the crucible, and in this state it was 
exposed to heat in a forge, in which upon another occasion, I 
had, in the presence of Mess. Hatchett, Howard, Davy, and 
others, completely melted a Hessian crucible lined and pre* 
pared in the same manner. The fuel which I used was the 
patent coak of Mess. Davey and Sawyer. In the present ex* 
periments I moderated the heat so as not materially to injure 
the crucible, and upon taking it out of the fire, the lining was 
generally found so compact and so firm that it remained m a 
solid mass after the crucible was broken. When the metallic 
cylinder occupied the space at the bottom, it was natural to 
suppose that it had been fused ; because in no other state but 
that of liquidity could it have run into the mould. In order 
however to prevent all objections I had the precaution to make 
the hole of a different diameter from the metallic cylinder, 
and to observe whether the necessary change in the shape of 
the latter ensued. If, after such a test, repeated as often as 
required, I perceived that the metal did not vary in its specific 
gravity, I thought myself authorised to conclude that it was 
exempt from air. 

M. RicHTER says that he had hoped to have put himself in 
possession of a consklerable piece of palladium, by repeating 



Platina and Mercury upon each other. 1 1 1 

with minute accuracy the process which I had recommended 
as the best. He precipitated a mixed solution of platina and 
mercury by a solution of green sulphate of iron ; and after 
varying the subsequent operations, to which he submitted the 
product he had obtained by this method, he was led to the 
following important conclusions amongst others of less conser 
quence. ist, That two metals, the separate solutions of which 
are not acted upon by a third body, may be acted upon, and 
even reduced to the metallic state, by that same body when 
presented to them in one and the same solution. 

sdly. That mercury is capable of entering into combination 
with platina so, that it cannot afterwards be separated by fire. 
•From the first of these conclusions it is evident, that njetals in 
their metallic state are not incapable of chemical action upon 
each other ; and from the second, that merpury can be fixed 
(if is purposely that I use the alchemical expression) by 
platina. 

In addition to the chemists abovementioned, I mus|: name 
two more who in Germany have been occupied by palladium. 
M. Tromsdorff, in a letter to the authors of the journal 
already quoted, mentions his having made sonie fruitless at- 
tempts to form this combination ; and M. Klaproth, in a letter 
to M. Vauquelin published in the idnnales de Chimie, for 
Ventose, an 12, likewise says that he could not succeed in 
producing palladium. 

Mess. Rose and Gehlen, as well as M. Richter, had con- 
ceived from my Paper a reJOiance ort the success of their 
experiments, which no words of mine had authorised, and 
have accused me of enforcing the truth of my results with a 
degree of certainty which their observations do not countenance. 



112 Mr. Chenevix an the Action of 

M. RicHTER supposed that the formation of palladium was 
attended with no difficulty ; and in general they have laid so 
much stress upon this charge, that I should be inclined to 
think my Paper had not been read by these chemists. In 
referring to it again, I find there is hardly a page in which I 
do not mention some failure, and no experiment, of the very 
fev/ which occasionally succeeded, is related without my 
stating at the same time that it was repeatedly unsuccessful. 
As far as regards palladium, it is ratjier a narration of fruitless 
attempts than a description of an infallible process, and more 
likely to create aversion to the pursuit than to inspire a confi- 
dence of success. The course of experiments which I had 
made, as well before as after reading my Paper to the Society, 
took me up more than two months, and employed me from 
twelve to sixteen hours almost every day. 1 had frequently 
seven or eight operations in the forge to perform daily, and I 
do not exaggerate the number of attempts I made during this 
time, as well in the dry as in the humid way, in stating them 
to have been one thousand. Amongst these I had four suc- 
cessful operations. I persevered, because even in my failures 
I saw sufficient to convince me that I should quit the road to 
truth if I desisted. After all my labour and fatigue I cannot 
say that I had come nearer to my object, of obtaining more 
certainty in my processes. Their success was still a hazard on 
the dice, against which there were many chances; but till 
others had thrown as often as I had done, they had no solid 
right to deny the existence of such a combination. On this 
foundation none, I believe, have established such a right. 
Mess. Rose and Gehlen do not say how often their experi- 
ments were repeated ; but it is probable that if they had been 



Platina and Mercury upon each other . 113 

' )>erformed very often, these authors would not have neglected 
to mention it. M. Richter states his merely as preparatory 
to more extensive researches; and M. Tromsdorff, as well as 

• M. Kx APROTH, mention little more than the fact. If the German 
chemists have concluded against my results, they have done 
so without just grounds, and without having bestowed upon 
them that labour and assiduity for which they are usually so 

• remarkable. ^ 

In this state of uncertainty the compound nature of palla- 
dium received an indirect, but a very able, support from some 
experiments of M. Ritter, the celebrated Galvanist of Jena. 
M. Ritter had ascertained the rank which a great number of 
substances hold in a Galvanic series, arranged according to 
the property they possess of becoming positive or negative 
when in contact with each other. He had established the 
following order, the preceding substance being in a minus 
relation to that which comes next. Zinc, lead, tin, iron, bis- 
' ninth, cobalt, antimony, platina, gold, mercury, silver, coal, 
galena, crystallized tin ore, kupfer nickel, sulphur pyrites, 
copper pyrites, arsenical pyrites, graphite, crystallized oxide 
of manganese. He had the goodness to try palladium in my 
presence, and found it to be removed, not only from what I 
believed to be its constituent parts, but altogether from among 
the metals, and to stand between arsenical pyrites and graphite. 
This result led M. Ritter into a new and general train of 
reasoning,' and induced him to undertake the examination of a 
great number of alloys, and of a variety of amalgams. He 
considered the subject as a philosopher; and his operations 
were those of a consummate experimentalist. It would be 
doing him an injustice to attempt an extract of his ingenious 

MDCCCV,, Q 



114 Mr. Chenevix on the Action of 

paper, which contains a series of the most interesting experi- 
ments. I diall merely observe for the present purpose, that 
it very rarely happened that the mixture of two metals bore 
any determinate relation to the same metals when separate ; 
that in every case the smallest variation in the proportions 
produced the most marked eflfects ; and that M. Ritter has 
furnished us. with an instrument calculated to detest the pre- 
;sence of such small quantities as have hitherto been considered 
as out of the reach of chemistry. As palladium presents a 
very striking instance of the anomaly, to which all compounds 
seem to be more or less subject, by being removed altogether 
from the series of simple metals, this may serve to support the 
other proofs of its compound nature. 

One of the principal objections of those who dispute the 
truth of my conclusions with respect to palladium, is grounded 
upon the repeated failure of all the methods I had made use of 
in forming it ; but this cannot be of very great weight, when 
we consider the uncertainty of many other operatk)ns of che- 
mistry. The most simple are sometimes liable to fail : and the 
easiest analyses have often given different products in the 
hands of different chemists, who yet enjoy indisputable and 
equal rights to the title of accuracy. The progress which we 
have made in some parts of the science has not removed the 
obstacles which impede our advancement in others. We have 
no method of proving the truth of an experiment except by 
repeating it : yet this often tends to show nothing more than 
contradictory results, and consequently the fallibility of the 
art. 

But a recent case has occurred which is perfectly analogous 
to that of palladium. A few years ago Professor Lampadius^ 



Platina and Mercury upon each otiier. 115 

in distilling some substances which contained sulphur and 
charcoal, obtained a liquid product of a peculiar nature. He 
repeated his experiments, but in vain : and after many fruitless 
attempts abandoned his researches, and confined himself to 
stating the fact to the chemical world. little notice was taken 
of it, and not much interest was excited by an experiment so 
likely to fail. Some time after this Mess. Clement and Desokmes 
obtained the same result, and attempted to produce the sub- 
stance a second time. They performed a vast number of ex- 
periments ; but their success bore no proportion to their ' 
diligence and zeal. They published an account of their process 
and its consequences, but gained little credit, as no person 
was fortunate enough to proitace the* same substance: Many 
disbelieved the experiments altogether, and denied the ex- 
istence of such a combination ; whilst others, less inclined to 
doubt, attributed- its formation to fortuitous circumstancesr 
which might never again occur together. In February, 1804, 
Professor Lampadius, in distilling some pyritized wood, though 
with a different intent, obtained the osame substance. As he 
had it now in his power to observe the phenomena that at- 
tended its formation, he discovered, and lias communicated to 
the world, a method of producing it, which^ never fails. Since 
his late paper upon the subject, as the necessary precautions ^ 
can be followed by every chemist. Mess. Clement and Des- 
ORMES have obtained that credit to which their experiments 
had',' in truth, always been entitled; and the formation, of 
what Professor Lampadius terms his sulphur-alcohol is no 
longer a result of chance, or accounted for by being supposed 
one of those subterfuges to which human pride resorts, in order 
to spare itself the confession of human, weakness. 



ii6 Mr. Chenevix on the Action of 

The observation of any new fact becomes a matter of general 
concern, and truly worthy of philosophic contemplation, th^ 
only, when its influence is likely to be extended beyond the 
single instance to which it owes its discovery- Whether water 
were a simple body or a compound could have been of little 
importance as an insulated fact ; but, connected with the vast 
chain of reasoning it gave rise to, it opened a new field for 
genius to explore. If in the present case our researches were 
to be confined merely to ascertaining whether palladium were 
a simple metal or a compound, all the advantages likely to 
arise from the facts observed during the inquiry would be lost; 
and an object of the most comprehensive interest would thus 
sink into a controversy concerning the existence of one more 
of those substances, which we have dignified with the name of 
elements. It was in this point of view that Mess. Richter and 
RiTTER considered the subject as far as they went, and a few 
facts are stated in my first Paper in support of the opinion, that 
palladium is but a particular instance of a general truth. 

By taking the reasoning cm this subject then, in its widest 
extent, we shall be led, I think, to the following conclusion : 
That metals may exercise an action upon each other, even in 
their metallic state, capable of so altering some of their prin* 
dpal properties as to render the presence of one or more of 
them not to be detected by the usual methods. In this is con* 
tained the possibility of a compound metal appearing to be 
simple ; but to prove this must be a work of great time and 
perseverance ; and can only be done by considering, singly 
and successively the different cases which it contains, and by 
instituting experiments upon each. When an affinity which 
unites two bodies, and so blends their different properties as to 



Platina and Mercury upon each other. 1 17 

make them apparently one, has taken its full effect, it will not 
be easy to separate them ; and this will be more particularly 
the case when neither of those substances is remarkable for 
exercising a powerful action upon others. The method of 
analysis therefore does not promise much success; and the 
labour of synthesis is sufHcient to deter any individual from 
the undertaking. , 

It is my intention now to exhibit one example of my position, 
and to prove that platina and mercury act upon each other, in 
such a manner as to disguise the properties of both. I shall 
therefore wave for the present all consideration of palladium, 
whichis in fact but a subordinate instance of the case before us.. 

. When a solution of green sulphate of iron is poured into a 
solution of platina, nb precipitate, nor any other sensible- 
change ensu6s. This Ihad already observed, and it has since 
been confirmed by all who have written upon the subject. But,, 
if a soluticHi of silver or of mercury be added, a copious preci- 
pitate takes place. This precipitate contains metallic platina 
and metallic silver or mercury ; some muriate of one or other 
of the latter metals is also present, as it is not easy to 'free the • 
solution of platina from all superfluous muriatic acid. But 
these salts are of no importance in the experiment, and can. . 
be separated by such methods as a knowledge of their chemical - 
properties will easily suggest. The proper object of consider 
ration is the reduction of the platina to the metallic state, . 
which does not happen when it is alone. I have tried to pro- 
duce the same effect widi other metals and platina, but I have 
not observed any thing similar. It is therefore fair to conclude,, 
that when a solution of platina is precipitated in a metallic state. 



ii8 Mr. Cmenevix on the Action of 

by a. solution of green sulphate of iron, either silver or mer^ 
cury is present. 

The precipitation of admixed solution ofplatina and silver 
requires no further caution than to fr^e thb' salt of platiha as 
much as possible from i muriatic' add ; fol* as I observed in; 
my former Paper, the eflfect of nitrate of silver : poured' into 
muriate of platina, is to produce a precipitate, not of muriate 
of silvery but of a triple muriate of platina and silver; It was 
by this experiment that I then proved the affinity of these two 
metals ; for when silver is not present, muriate of platina is 
among the most soluble salts* The best method of presenting 
the three solutions of platina, silver, and green sulphate of iron 
to each other, is first to pour the filtered section of the last 
into the solution of platina, and then, after mixing them tho* 
roughly together, to add the solution of Jsilver by degrees, and 
to stir them constantly. In this, as in all similar operations; 
the presence of all acids, salts, &c. excepting those necessary 
for the operation, should be avoided ; and if proper proportions 
have been used, and all drcumstances attended to, the pred-^ 
pitation of these two metals will be very complete. 

But the precipitation by a soluticm of mercury requires to be 
further considered, as the state of oxidizement of this metal, 
as well as the acid in which it is dissolved) produces a consi- 
derable modification in the result. In the first place the oxide> 
at the minimum of oxidizement, dissolved in muriatic acid, is 
unfit for the experiment ; and even* the red oxide dissolved in 
the same acid, or corrosive sublimate, is not the most advan- 
tageous. When a warm solution of the latter is poured into a 
mixed solution of platina and green sulphate of iron also 



Platina and Mercury upon each other. 119 

warm, as in the case ofsilver, these substances are brought 
into contact under the most favourable: circumstances. Yet 
even thus the precipitation is slowly and imperfectly formed, 
often not till several hoiu*s have elapsed; and sometimes a 
very great deficiency of weight is observed, between the quan- 
tities used and those recovered directly by this .method. If a 
solution of nitrate of tmearoury be us6d, the eflfect is produced 
more rapidly, and the precipitate is more abundant. The pre- 
cipitation of muriate of platina by nitrate of silver, and the 
combination which ensues from it, suggested to nie an experi- 
ment which I must state at length, as from the result of it 
consequences are deduced which modify some of the experi- 
ments of piy former Paper. 

It occurred to me that a method .of uniting platina and 
mercury without the intervention of any other metal, or of any 
substance but the solvents of these metals might be accom-* 
plished as in the case. of silver and platina. I therefore poured 
a solution. of nltrale of mercury, which solution being at the 
minimum of oxidizement, consequently formed an insoluble 
muriate with muriatic acid, into a solution of muriateof platina. 
The result was a triple salt of platina and mercury, which 
.when the mercury was completely ahd totally at th^ minimum 
of oxidizement was nearly insoluble: To procure it in this 
state it is sufficient to put more metallic mercury into dilute 
nitric acid tban the nitric acid can dissolve, and to boil them 
together. This triple salt of platina and mercury shall be pre- 
sently examined. From this it is evident that to produce the 
union of .pJatina and mercury, the latter being at its minimum 
of oxidizement in mtric add the addition of green sulphate of 
iron is superfluous. 



ISO Mr. Chenevix on the Action of 

But if mercury be raised to its maximum of oxidizement In 
nitric acid the case is different, for no precipitation occurs till 
the green sulphate of iron is added. The most advantageous 
method for preciprtating platina and mercury by green Sulphate 
of iron is, I believe, the following. Mix k solution of platina 
with a solution of green sulphate of iron, both warm^ and add 
to them a solution of nitrate of mercury at the maximum of 
oxidizement! also warm. It is necessary to avdid excess of add, 
sialt, 8cc. in this as in all such cases. With due care the preci- 
pitation of both metals will then be complete. 

By comparing the experiments made with mercury and 
platina with those made with silver and platina, a striking 
resemblance will be found. This induced me to pursue the 
analogy, and to examine whether, independently of the action 
^ of platina, mercury had not the same property of being preci- 
pitated by greien sulphate of iron as silver. Nitrate of silver is 
precipitated by green sulphate of iron, but muriate of silver is 
hot sensibly acted upon by the same reagent. The insolubility 
of muriate of silver might be alleged as the cause of this, if I 
had not tried the experiment by pouring nitrate of silver into 
green muriate of iron, in which case all the substances were 
presented to each other in solution. The result was not re- 
duction, but muriate of silver and nitrate of iron. This fact 
rests upon a much more extensive basis than mere mechanical 
circumstances ; and, if pursued with the attention it deserves. 
It would lead us into the wide expanse of complicated affinities 
and their relations. From reasoning alone we should be dis^ 
posed to IJiink that an acid, so easily decomposed as the nitric, 
would be suffident to prevent the reduction of a metal which 
it can dissolve. But on the one hand it can spend its oxygen 



Platina and Mercury upon each other. 121 

upon a part of the oxide of the green sulphate of iron, while 
on the other its affinity for oxide of silver is not powerful 
enough to retain it, when there is another part of the oxide of 
iron {M-esent to deprive it of oxygen. But the affinity of mu* 
riatic acid for oxide of silver, one of the strongest at present 
known, is sufficient to counterbalance all the other forces. 
There are many other instances of the same kind. 

If then a solution of green sulphate of iron be brought into 
contact with either soluble or insoluble muriate of mercury, 
no reduction takes place ; but if mercury, whether at the maxi* 
mum or the mininlum of oxidizement, be dissolved in nitric 
acid, and green sulphate of iron be added, the mercury is 

* 

precipitated in the metallic state. 

These experiments are much stronger examples than the 
former of the effects produced by complicated affinities. They 
are of importance not only as objects of general consideration 
but in their application to the present subject. They most nu^ 
terially modify and are indispensable to the accuracy of the 
results I formerly stated ; but I was not aware of them at 
the time I first engaged in the investigation of this subject . I 
can also now explain a very material difference between some 
proportions observed by M. Richter and myself in an expe* 
riment which that chemist had made as a repetition of one of 
mine. 

I had poured a solution of green sulphate of iron into a 
solution of 100 parts of gold and itoo of mercury, and had 
obt^ed a precipitate consisting of 100 of gold and 774 of 
mercury. M. Richter repeated, as he terms it, this experi- 
ment ; that is, he used 100 of gold and 300 of mercury, and 

MDCCCV. R 



129 ' Mr. Chenevix on the Action of 

obtained a precipitate weighing los. He is surprised at the 
difference of weight between our results, which might be 
owing to his method of repeating the experiment ; but die real 
cause of this difference lies, as I suppose, in my having acci- 
dentally used nitrate instead of muriate of mercury. I had 

« 

never observed that with mercury and silver this operation 
had failed, and it must have been, because, on account of the 
known effect of muriatic salts upon those of silver, I had 
naturally avoided using a muriate of mercury. 

But the state of the nitrate of mercury which is used with a 
solution of gold is not indiiferent. As green sulphate of iron 
reduces mercury when dissolved in nitric acid, as well as gold, 
it is necessary to mix the solutions of those metals before t][ie 
green sulphate of iron is added, in order that both may be 
acted upon tc^ether. If the nitrate be at the minimum of oxir- 
'dissem^ht, a precipitate is immediately formed upon mixing the 
solutions of gold and mercury* Calomel is produced by the 
muriatic add of the solution of gold and the oxide^of mercury; 
whilst the gold is reduced to the metallic state by a portion of 
the oxide of mercury becoming mor^ oxidized, and formipg 
the soluble muriate. The precipitate consists of calon^el, of 
metallic gold, and of a very sqiall portion of mercury which 1 
believe to be in the same state ; my reason for thinking so, is, 
that I have often observed, that a glass vessel in which I had 
sublimed sotne of it, wa9 lined with a thin gray metalhc coat. 
'If, on the contrary, a nitrate pf mercury be highly oxidized, 
JK) precipitate nor reduction of gold takes place until the green 
sulphate of iron is added. 3ut at any rate the precipitation of 
'gdid and mercury, or of silver and mercury by green^ sulphate 



Platina and Mercury upon each other. it$ 

ef iron cannot be adduced as an argument to support the 
affini^ of these metals, since the effect is the same, whether 
they are separate or united. 

These preliminary considerations were necessary as well 
for the rect^cation of my former experiments as for the pur- 
suit of my present object ; and now to return to platina. 

Exper. 1 ! If a solution of highly oxidized nitrate of mercury 
be poured into a mixed solution of platina and green sulphate 
of iron, the first action which takes place passes between 
the muriatic acid of the solution of platina and the oxide of 
mercury, by which a muriate of mercury is formed, but retained 
in solution. This effect makes it advantageous to use a greater 
quantity of tihe solution of mercury than is merely capable of 
drawing down the' given quantity of platina along with itself 
ki the form of a metallic precipitate. When this precipitate is 
washed and drited, it will be found to weigh much more than 
file original quantity of platina ; and the augmentation of weight 
has no limit but those of the mercury and the green sulphate 
of iron employed, j^ut even after nitric acid has been boiled 
for a long time and in great quantities upon this precipitate, 
until it no longer dissolves any part of it, there still re- 
I mains more undissolved matter than the original weight of the 

platiha used in the experiment. By exposure to heat little 
more is left in general than the original platina ; and some* 
times even a diminution may be observed ; for as the experi- 
ment is not attended with uniform success, it does not always 
happen that the whole of the platina is precipitated, but a 
portion of it will sometimes resist the action of the green sul- 
I^ate of iron, even when sufficient mercury has been used. 
Before the }»recipitate has been exposed to heat it is dissolved 



A 



1S4 Mr. Chenevix on the Action of 

more easily than platina by nitro-murlatic acid ; and the solu* 
tion when nearly in a neutral state gives a copious metallic 
precipitate, (yet not equal to the quantity employed,) when 
boiled with a solution of green sulphate of iron. 

Exper. 2. When a mixed solution of plsrtina and mercury is 
precipitated by metallic iron, a quantity equal to the sum of the 
former metals is generally obtained. After nitric acid has been 
boiled for a long time upon the precipitate so formed, the original 
weight of platina, together with a considerable increase, remains 
behind, nor can nitric acid sensibly diminish it. It yields morb 
easily than platina to the action of nitro-muriatic acid, and its 
solution in that acid, when neutralized, gives a precipitate, as 
in the former experiment, by green sulphate of iron. If this, 
precipitate be exposed to a strong heat after it has been boiled 
with nitric acid, it loses a great part of its weight, and the; 
platina alone will generally be found to remain. 

Exper. 3. When a quantity of ammoniacal muriate of platina 
is treated according to the method of Count Mufifsm Pushkik. 
to form an amalgam, and, after being rubbed for a considerable 
time with mercury, is exposed in a crucible to a heat gradually 
increased till it becomes violent, a metallic powder remains in? 
the crucible. This powder is acted upon by nitro-muriatic acid, 
and when the solution is neutralized, a copious precipitate is 
formed upon the addition of green sulphate of iron. This effect 
takes place even after the metal has been fused in the manner 
described in the former part of this Paper. 

Exper. 4. If sulphur be added to the ingredients recom- 
mended by Count Mussin Pushkin, and the whole treated as 
in the last experiment, the quantity of precipitate caused by 
green sulphate of iron in the nitro-muriatic solution of tije: 



Ptatind atd Mercury upon eofh^l^. t35 

button which results from the operationr is generally more 
considerable. 

. Exper. 5. If sulphur be rubbed for some time with ammo- 
niacal muriate of platina^ and the mixture be introduced into a- 
small Florence flasks it can be melted on a sand-bath. If 
mercury be then thrown into it, and tber whole be well stirred 
together and heated^ it may afterwards bjB exposed to a very 
strcmg fire, and melted into a button. If this be dissolved in 
nitro-muriatic add, it will give a precipitate, as in the former 
cases, by green sulphate of iron. 

Exptr. 6. If a current of sulphuretted hydrogen gastbe sent 
through a mixed solution of pladna and mercury, ^d the 
predpitate which eitisup^ rbe collected, the metal may be re- 
duced by heat; imd wjt^ the addition; of borax^ it may be^ 
melted into a button which will not contain any sulphur. Green* 
sulphate of iron €au$es a predpitate in the solution of this* 
metal also. 

Exper. 7. If to a mix^ solution of platina and mercury^ 
phosphate of ammonia be added, a precipitate takes place. If 
this be collected and reduced, it will be acted upon by green^ 
sulphate of iron poured into its solution, in the same manner as. 
the metallic button? in the preceding examples. 

Exper. 8. I have already mentioned that when a solution of 
nitrate of mercury ; at the minimum of pxidizement,is pouredinto 
a solution of muriate of platina, a mercurial muriate of platina is^ 
precipitated. The supernatant liquor may be decanted and the. 
residuum washed ; if this be reduced and afterwards dissolved 
HI nitro-muriatic acid, it will yield a precipitate with green; 
sulphate of iron. This method appears to me to be the neatest' 
£Qjr combining platina and, mercury, as the action wliichtakesci 



iftS Mr. Chenevix m The' Action of 

place is independent of every kubsfance «xcspt the vm^tolfi 
themselves. 

Exper: g. One of the most delicaite tests that I have observed 
in chemistry is recent muriate of tin, which detects the pre- 
sence of the smallest portion of mercury. When a single drop 
of a saturate solution of neutrailized nitrate or murfeite of 
mercury is put into 500 grains of water, and a few drops of a 
saturate solution of recent muriate of tin are added, the liquor 
becomes a little turbid, and of a sinoke-gray colour. If these 
500 grains of liquid be diluted With ten times their weight of 
water, the effect is of course diminished, but still it is per- 
ceptible. I had oh a forttier occasittn observed the action of 
recent muriate of tin upon a solutioh of plsitina. If a solution 
6f recent muriate of tih be poured iht6 ia mixed sdliition of 
platina and mercury, not too concentrated, it can hardly be 
distinguished from a^siihple solutic^ of pktiha. 'But if too 
much mercury be present the excess is acted upon asfiaercury \ 
and the liquor assumes a darker o^lotirthail with plaltna alone. 

From all these experiments it is evld^t.diat mercury ooi 
sex Upon pktina,'and confer upon it the property of being pre- 
cipitated in a metallic state by greeti sulphate of iron. By 
Experiments 1 and s, it is proved, 1st, That platina can protect 
a considerable quantity of meix;ury from the action of nitric 
add ; and sdly. That mercury can increase the action of nitro- 
muriatic acid upon platina. From Experiments 3, 4, 5, 6, 7, 8, 
it appears that merciiry dan conibine with platina in such a 
manner as not to be separated by the degree of heat necessary 
to fuse the compound, since after the fusion it retains that 
property, which is essentially characteristic of the presence of 
mercury in a solution of platina. The 8th Ea^eriment proves 



ma /mdMn^ury upon each other. 1^7 

th^tUie^actipn of mercury upp)i pl»^|ia is not conimed to the 
i^etallic state ; l>ut tint the^e metals can combine and form an 
insoluble triple s^t wjth ian acid which produces a very soluble 
pGopgppund with.platina 2()Qne. Tl^ gth Experimmt /shows that 
^lat^n^ c»^ rje^;^ in solution a cerjtainiqiiantity pf mercury, 
^d prev€;nt its ^reduct^on by a substance wh^ch acts most 
l^pv^eir^ly to thf^ ^%cit, when platina is not present. That 
part of thq ^ general pos^flRrtl^QrefQre whidi is the object of 
.tfai^ P.^V^TJ^^ffcgtYfid^ if, d>^se r^xpierixoentSf upon being repeated 
by other ch^p^^f^^ §lf^l.|)e fpund.to be accurate. 

One qr, tyfQ pf^hei^jboye experiments seem to be in contra*- 
rdicto tpj^pqfip, ijUt I i^ ,?tet^4 in my Paper upon palladium ; 
.foTrin^th^ j^espi^tj^^n^ples^.plafii^a protfjcts mercury against 
thj^racti9n of nitric acjd ;; whereas in palladium the mercury is 
jiot only^acted upon iUelf« but it conduces to the solution of 
platina. ip the swp^ aqidr (I, am w;ell^ aware of this objection ; 
.but ,fi9*ifraiijg /myself l;a myj^pre^aep-t, object, I shall wave all 

'%ltei4i?9VWP-ft^ jt tjllj^Qther. oppoiptmiity. In.the meap 
.time,.hf)wever,.it may be laid dawn as an axiom in chemistry, 
that;.^)xe,.$tYO]^gei^tftai!initjes are those^ which, produce in any 
.^hstahQe:t^]gire^e^,t .d^atioii -firoQi its usual properties. 

When a bijtt$» pfi^hp ^Upy pij patina and mercury as ,pre- 

pared by apy of the above methods, is dissolved in nitro- 

. muriatic, ^d^a^jd Bftfprwards, i^edpit^^ed by green sulphate pf 

>^^ %f«tire;flHaptitytof,^ used i^ J}eldpm:ol>taujed. 

A ,cpi>«deral[%, portipn^pf plaj^^ .r^sjsts th^^'actjion of green 

sulphate, of ffQni;;^d reqiainjB |n solution. This may be looked 

..upon as the excess. of platiaa, and cap be recovered by a plate 

of iron. Hence it appears that less mercury is fixed, than can 

4et^ip93|ine the <pi5^JBi^twn pf tl^ entire quanfity of platina; 



Ufi8 Mr. CheneviX M the Action of 

yeit m this tstate it can draw down sl greater cjuantity df tlie 
latter, than when it i^ merely poured into a mixed solution of 
platina, not before so treated. Indeed the whole of these 
experiments tend, not! tehly to show that these tw6 metals 
exercise a very powerful action upon each other, but that they 

. r 

are capable of grekt variation in the state of their combihatidn; 
and also that substances pos»sessing different properties have 
resulted from my attempts to combine platina with mercury/ 
This observation furnished me with a -method of atscer- 
taining, or at least of approaching to the knowledge of, Ae 
quantity of mercury thus fixed by platiha, and in combination 

m f • • • 

with it. The experiment, however, having been seldoin attended 
with fuH success, I m'ehtidh the. result with the entire consci* 

* • • • > 

ousness of the uncertainty to which it is subject. I observed 
the increase of weight, which the original quantity of platina 
had acquired in som6 cases after it had been treated with 
mercury, and fused into a button. I counted that augmenta- 
tion as the quantity of mercury fixed, I then determined how 
much was jprecipitated by green sulphate of iron from a solu- 
tion of this alloy, and supposed it to contain the whole quantity 

• * • • • 

of mercury found as above. But, even if attended with complete 
success, there is a chemical reason which must make us refuse 
our assent to this estimate. It is possible, and not unlikely^ 
that a portion of mercury may be retained in solution by the 
platina, as well as that a portion of the platina may be preci- 
pitated by means of the mercury.. The mean result, however, 

♦ * • • • 

was that the precipitate by grieeh sulphate of iron consisted of 
about 17 of mercury, and 83 of platina, when the specific 

gravity was about i6\ 

. • • * 

With regard to palladium, lest it should be supposed thgt 



Platina and Mercury upon each other. 1 29 

either my own observations, or those of others have given me 
cause to alter my o{»nion. I will add that I have as yet seen 

« 

no argum^its of sufficient weight to convince me, in opposition 
.to experiment, that palladium is a simple substance. Repeated 
failure in the attempt to form it I am too well accustomed to, 
not to believe that it may happen in well conducted operaticms ; 
but four successful trials, which were not performed in secret, 
are in my mind a sufficient answer to that objection. By deter- 
mining the present question we may overcome the prepos- 
session conceived by many against the possibility of rendering 
mercury as fixed, at an elevated temperature, as other metals : 
we may be led to see .no greater miracle in this compound 
than in a metallic oxide, or in water, and be compelled to 
take a middle path between the visions of alchemy on the one 
hand, and the equally linphilosophical prejudices on the other, 
which they are likely to create.. In the course of experimients 
just now related, I have seen nothing but what tends to con- 
firm my former results, yet the only means which I can, after 
all, prescribe for succeeding, is perseverance. 

To ascertain whether the opinion of Mess. Fourcroy and 
VAUguELiN, that the nev/ metal was the principal ingredient 
jn palladium had any jUst foundation, I observed the methods 
they have recommended for obtaining pure platina ; but I did 
not perceive any difference in the facility with which either 
kiiiid of platina coinbined with mercury. 
' : r might have add^ some more experiments to corroborate 
the evidence I have adduced to prove my assertion of the 
fixation of mercury by platina; but Mess. Vau^uelin and 
Fourcroy have promised the Institute of France a continuation 
of their researches, and M. Richter concludes his paper with 

MDCCCV. S 



igp Mr. Chenevix tm the Action^ &c. 

saying that he vnM return to the subject* From the labourb of 
such persons some great and important fact must issue^ and I 
«hope that the present subject will not be excluded from their 
consideration. The facts contained in this Paper cannot be 
submitted to too severe a scrutiny ; and no judge can be more 
rigid or more competent than the very person who was the 
iirst to doubt my former experiments. But it is necessary to 
be observed by whoever shall think them worth the trouble of 
verifying, that even these experiments are liable to fail unless 
proper precautions axe used : that I have never operated upon 
less than one himdred grains ; and that the results, which I 
have stated, however simple they may appear, have been the 
constant lahpur of ;some weeks. 

POSTSCRIPT. 

Since this Paper was written Dr. Wollaston has published 
some experiments upon platina. He has found that palladium 
is contained in very small quantities in crude platina. This fact 
was mentioned to me more than a year ago by Dr. Wollaston. 
I have not yet seen a copy of his Paper ; but I dhall merely 
observe here that, whatever be the quantity of palladium found 
' in a natural state, no conclusion can be drawn as to its being 
simple or compound. Nothing is more probable thah tbtt 
nature may have formed this alloy, and formed it much betteor 
than we can do. At all events the amalgamation to which 
platina is submitted befwe it reaches Europe is sufficient to 
account for a small portion of palladium. 



C »si 3 



VI. Jtn Investigation tf all the Changes of the variable Star in 
Sobieski's Shield, from five Tear^s Observations, exhibiting its 
proportional illuminated Parts, and its Irregularities of Rota-^ 
rtbn ; toith Conjectufes rejecting tmenlightened heavenly Bodies. 
By Edward Pigott, Esq. In a Letter to the Right Hon. Sir 
Joseph Banks, AT. JB. P.R.S. 



Read February 7, 1805- 

; HE object of the lltst part of ^s Paj^ieor is a further in- 
vesication of the periodicaLdnd other changes of brightness 
of one of the variable stars I discovered in 1795, *hat in 
SdBiESKL's shield^ ^n aecount of v^mh the Royal Society dSI 
me th^ honour of publishing in their Transactions. Those 
determinations being deduced from a few periods made mat 
the time of discovery, must of couitte remain ^msatisfactory, 
however exact tiie^cfbeervations thbiiiselves may be, until con- 
firmed by an additiortal: set, or by others madid at a greater 
interval of time.; for \\fhich purpose I occasionally continued 
keejfung ^ journal of its-ehanges for near five 3rears, and' am" 
happy to find tibat they have answeited my eitpeetation, parti- 
culajrly by giving us ^ insist into- ite irr&gidadties, as wilJt 
be shewn heroaftoiv. 

Variable Stkr in Sobieski's Shield. 

S 2 



13« 



Mr. Pigott's InvesfigattM of the Changes 



Its rotation on its axis was, in 1796, estimated at 6sl\ days, 
from a mean of six observations of its greatest and least 
brightness. Here follow about 26 similar determinations, most 
of them the results of very accurate observations ; and as they 
probably will in future be compared with others, I have exa- 
mined them repeatedly with the utmost care, attending parti- 
cularly to the progression of their changes. 

Table 1. 



Dates when at its greatest 
Brightness. 


Maanw , 
tildes. 


DateSs wfae^ at its least 
Brightness. 


Magni- 
tudes. 


1796. September 17 
November 13 


5 
5- 


1 796. September 3 
October 22 > - 


6. 
6' 


1797. May 14: - 
August 7 
October 15 - 


5+ 
65 


1797- J^y 10 *- - 

September 15 
November 6 


$.6 
6 
6 


179^- July 29 . - 
October 25 - 

December 5 : : 


5+ 
5.6 

5-6 


1798. Jaiy 10 - - 

September 15 
November 10 


6 
6 


1^99- J^^ ^ • • 
August 7 

October 11 - 

1801. July 14: 

September 24 


6.5 

5 

5+ 
5 
5 


^799' July 4 

September 16 

November 5 : 

1801. June (middle): 

August 21 - 

October 1^ - 


7 
6 

6.7 

6 

6.7 

6.5 



The + and — annexed to the magnitudes denote them to 
be more or less bright ; the doubtful I'esults are marked 
with dots ; all the others are esteemed exact, except those of 
August 7, 1797, ^™1 August 21, 1801, which are in a small 
degree less so. From these determinations the rotation on its 
axis may be computed as follows. 



i8oi. 



of the variable Star in Sobieski's Shield. 133 



Table 11. 



Middle of its greatest Brightness. 



Dates. 



Interval in Number of 

Days* Periods. 



1796. &ptemberi7i _ j _ 
November 13/ ^' ^^uax vw 

1797. May 14, : 1 g^ . _ 
August 7 - J ^ "" " 



} 69 
} 88 
} 65 



August 7 - 
October 15 

1798. July 29 - 
October 25 

1799. August 7 - 
October 11 

1796. November 131 182 

1797. May 14 : - / or 61— 

1796.. November 13-1 267 
1797. August 7 - J or 67— 

1797. October 15 -i 287 

1798. July 29 - - J or 5^^ 

1 798. October 25 n 286 

1799. August 7 - / or 57+ 



July 14 : ^ 1 
September 24/ ' ' 



igi| 1 Mr. Pi ojott's. hvettigatim of tA# Changes 



TaUe m. 



Middle (^ its least BriglUness. 



Dates. 

1796.^ Septeml?^r a 
October 22 - 

1797. July 10 .r 

September 15 

September 15 
November 6 

1798.. July 10 - - 
September 15 

, September 15 
November 10 

1799- My 4 ^ 

September 16 

September 16 
November 5 : 

1801. August ar- 
Octo^ber ift - 

1 796. October 2F& - 

1797. Jul}rio - 

1797. November 6 

1798. July 10 - - 

1798. November 10 
1799- July 4 - - 



Intctfind 
Dayt. 

49 



67 



Number of 
Periods. 



5* 



6f 
5^ 



1^. . 

^ ■ 

s6i 
or 65+ 

or 6ii 
or 59 



- equal to - 



€^ibe 



Star in Sobieski's Shield. 



136 



From all these results it appears, that the disagreements 
between them are far greater when at its full brightness than 
at its least ; I shall therefore^ in summing up the first set, 
omit two of them, as they evidently differ considerably from 
the others. 



Table IV. 



Rotation froip Observations of its 


Rotation from Obsenrations of its 


foil Brightness* 


least Brightness. 


Days. 


Day*. 


S7 


49 


69 


67 


65 


5« 


«i— 


€7 


S^j^ 


74 


S7i 


so 


57+ 


56 


7« 


5« 




6S+ 


by it* Aill Inightnes* 03-{' on a mean. 


6ii 




59 




By its least ditto 59^ on a mean. 



A mean of these two means being 6ij^ days, agrees with the 
first deductions to 1^ day, a coincidence that certainly I could 
not flatter myself would have happened : yet it must be re- 
membered> that the intervals with ccmsiderable perturbations 
were omitted; for, .had they been included, the length of 
period resulting from its maxima oi brightness would have 
varied much mcure from that obtained from its minima. I shall 
now proceed to examine some of its other changes. 



136 



Mr. Pigott's Investigation of the Changes 



fable V. 



Decrease from the Middle of its full 
firightness to the Middle of itB 
least. 

See Table I. 



22 



1796. September 17 1 ,.^-. 
October 22 /S5 ^ays. 

1797. May 14: - -I 
July 10 - J ^7 . 

August 7 . 1 
September 15/^^ 
October 15 - t 
- November 6 J 

1798. July 29 - ig 
September 15/* 
October 25 -1 g 
November 10 J 

1799- August 7 - n 
September 10 J* 
October 11 t 
November 5 J ^ 

1801. July 14 - 1 g 



August 2 
September 24 n 
October 16 J 



22 



Increase from the Middle of its least 
Brightness to the Middle of its 
full. 

Sec Table I. . 



|22 



October 22 
November 13 

1797. July 10 . 1 g 
August 7 - J 
September 15i^q 
October 15 J ^ 

1798. July iQ - I 

July 291 - - J ^ 

September 15 1 
October 25 J^ 

1799. July 4 - - 13. 

August 7 - J^^ 
September ^6^ 
October 11 J ^ 
1801. August 21 - -I 
September 24)^* 



27+ on a 
mean I 



S4onaffiean. 

The sum of these two means (61-f ), agreeing so satisfac- 

. • . 

torily with the whole rotation (61^), no correction is requisite, 
as was the case with the former determinations of 1796 to 
reduce them to 28 and 35 days, results that differ considerably 
from the above (34 and 27-f-) ; but as they were deduced 
from only two intrvals, the disagreement cannot be of any 
consequence, provided the number of each set ht proportionally 



of the variable Star in Sobieski's Shield. 



137 



attended to in the computation, and then the mean of the whole 
will be 33-4- and 29— days : thus it appears that the time of 
the decrease is longer than that of the ijicrease^ and consequently 
that the places of the full and the least brightness are not 
situated at the distance of half the circumference from each 
other : the like circumstance will be found to be the case with 
most, if not all, of the variable stars. The next particulars 
to be reviewed are the durations of its brightness without any 
perceptible change^ while at its maximum and minimum. These 
determinations require a tolerable succession of observations ; 
where therefore that is not the case, they are omitted. 

Table VI. 



Duration of Brightness at its Maximum. 



September 17 
November 13 

October 15 
1798. 
July 29 
October 25 - 
December 5 

June 1 
August 7 - 
October 11 - 
1801. 
September 24 



Days. 

9 

8 



3« 



Magni- 
tudes. 

5 
5— 



- 6.S 



6 
10 - $.6 

10 or more 5*® 



16: : 
8 
8 



- 6.5 

- 5 



15:* - 



Duradon of Brightness at its Minimum. 



1796. 

September 3 
October 22 - 

1797- 
July 10 

September 15 

5+pfovember 6 

1798. 

July 10 

September 15 

November 10 



^799' 

5+|July 4 

September 16 
November 5 
1801. 
October 16 - 



Days. Magni- 

tuoes. 

7 - 6 
8-6 

24 - 5-6 
18 : - 6+ 

6-6 

12-6 

9-9 
8-6+ 

9-7 
10-6 

16 : - 6.7 
9 - 6.5 



MDCCCV. 



138 Mr. Pigott's Investigation of the Changes 

It appears in general by my journal, and from these results, 
that when the degree of brightness at its maximum is less than 
usual, and its minimum not much decreased, the changes take 
place but very slowly, and cannot be settled with much accu- 
racy, unless the observations have been made frequently, and 
with great attention ; therefore, in summing them up, I think 
four of the first set and three of the second may be omitted, 
and theft the duration at its maximum will be on a mean 8 + days, 

and ditto so— days 
when it does not attain its usual brightness ; 
and at its minimum - - - on a mean 9— days, 

and ditto 20 — days 
when its decrease is not so great as usual ; the former obser- 
vations make them 14 and 9 days. 

Some of its degrees of brightness annexed to the results, 
have occasionally been noticed, as far as it was necessary, but 
the list of them I am going to give, is more exact and full. 
It will be there seen, that its brightness is seldom the same for 
two or three successive periods ; that the change in half a 
rotation is sometimes from the 5th to the 7th magnitude, and 
sometimes. only half a one or scarcely perceptible : its decrease 
has also be^n greater than by the former observations, parti- 
cularly on September 15, 1798, and August 9, 1803,* when it 
was less than the 9th magnitude, or had even disappeared. 

• Added since the Paper was writtea. 



f^the variable Star in Sobieski's Shield, 



139 



Table VIL 



Dates* 



r Magnitudes when at 
\ its fall Brightness. 



1796. September 17 
November 13 

1797. May (middle) 
August 7 
October 15 

1798. July 29 
October 25 
December 5 

August 7 
October 11 
1801. July 14 

September 24 



5 
5 
5 

& 

6.5 

5 
5.6 

6.5 

5 
5 
5 
5 



small 
bright 

bright 



bright 



Dates. 



r Magnitudes when at its 
\ least Brightness. 



1796. September g 
October 2 a 

1797- July 10 

September 15 
November 6 

1798. July 10 

September 15 
November 10 

1799- My 4 

September 16 
November 5 

1 801 • June ( middle ) 
August 21 
October 16 

1803. August 9* - 



6 
6 
5.6 
6 bright 

6 

9or o 
6 bri^t 

7 
6 

6 

6.7 
6.5 
9 or o 



In concluding these determinations I shall collect together, 
as follows, in one view, all the different changes that have been 
examined ; the first column describes them, the second exhibits 
the present results, the third the former ones, and the last 
column a mean of both, computed proportionally according to 
the number of observations of each. 

* Added since the Paper was written. 



/^ 



Ta 



140 



Mr. Pigott's Investigation of the Changes 



Table VIIL 



Rotation on its axis - - 

Duration of brightness, at its maximum, 

without any perceptible change 
Ditto, when it does not attain its usual 

brightness - - - 
Duration of brightness at its minimum, 

without any perceptible change 
Ditto, when it does not decrease so much 

as usual - 
Decrease in time, from the middle of its 

full brightness to the middle of its 

least - - - - - 
Increase in time, from the middle of 

its least brightness to the middle of its 

full .... 




Days, 
onameaxi. 

62— 

9i 



33+ 



29— 



Extremes of its different degrees of "| 
brightness ; with a mean of its usual [ 
variations - - - - J 



5+ 
9or 

o 



I 5+ 
7.8 



5. 
6 



of the variable Star in Sobieski's Shield. 141 



SECOND PART. 

Fontainbleau> iSoj* 

These essential variations of the star being thus settled with 
considerable precision, we may proceed to examine some of 
its other phenomena, particularly one common to most of the 
variables, as likewise in some degree to our sun, viz. that the 
times of their periodical returns of brightness are, in general, 
IRREGULAR, a circumstance I apprehend sufficiently interesting 
to engage our attention, at least I have ever thought so, and 
was thereby induced a few years past to make a succession of 
observations on one of them, in hopes of finding in what 
manner such irregularities took place, or at least to leave to 
future astronomers determinations, that might lead them to 
form some ultimate opinion thereon. I therefcfre chose for 
that purpose the star in Sobieski's shield y on account of the 
time of its revolution on its axis being comparatively of a 
moderate length, viz. 62 days, and shall here have the honour 
of laying before the Society the appearances that occurred, 
point out the various results deduced from the observations, 
and attempt to explain them. The two following Tables are the 
observed middle times of its full and least brightness, with de- 
ductions of the star's apparent rotation from single intervals, 
which in the present examination can alone be admitted, be- 
cause a mean taken of two or several would in general make 
such irregularities disappear, by the long and the short ones 
compensating each Other. The remarks for the present need 
not be attended to, as they are chiefly to explain the reliance 
tliat may be put on some of the observations. 



14* 



Mr. Pigott's Investigation of the Changes 



Table IX. 



The observed middle Times of 
lis full Brightness. 



1795. October 1 
December 10 : 

1796. April 10 
June 18 - - 

July 27 

September 17 
NovemJ)er 13 

1797. May 14 : 
August 7 
October 15 - 

1798. July 29 - 
October 25 - 
December 5 : 

1799- Ju^ei: 

August 7 - 
October 11 - 

1801. July 14: 

September 24 
November 1 



} 



Apparent 

Rotations 

in Days. 



70 



69 



39 



5« 



57 



85 
69 



88 



41 



67 
65 

7a 
38 



Remarks^ 

chiefly to illustrate some of the 

Observations. 



{By the observations of November^ &c. it 
seems probable it had not obtained its full 
brightness before December io« although 
possibly much later. 



r The increase towards Jul^ 27 was so 
1 slight that I had much hesitation in adopt- 
ee ing it as a full brightness ; if omitted* the 
J interval will be 91 days. See Phil. Trans. 

Li797- 



{The fill! brightness in May is doubtful 
to only about 6 days; the observations 
afterwards* to August the 7thj were made 
with tolerable regularity. 



{ 



A regular succession of observations 
were made between July and October 25. 

{The last observation made, was onDe- 
cember io» when it shewed no appearance 
of decreasing, although it had been 16 
days at its full brightness. 

The full brightness lasted a fortnight. 



f The observation of July 14, is doubtful 
< to a few. days, to which perhaps the excess 
[ may be attributed. 

A regular succession of observations 
were made between September and the 
middle of November. This last determi- 
nation was deduced after the first part of 
this Paper was finished. 




of the variable Star in Sobieski's Shield, 



143 



Table X. 



The observed middle Times of 
. its least Brightness. 



1796. March 4 
May 10 

July 19 

September 3 
October ss - 

1797- July 1^ 

September 15 
November 6 
1798. July 10^ 

September 15 
November 10 

1799- July 4 

September 16 
November 5 : - 
1801. Middle of June: : 



August 21 - 
October 16 



. } 



Apparent 

Rotations 

in Days. 



67 

70 

46 



49 



67 



5« 



67 
56 



74. 



50 



5^ 



Remarks, 

chiefly to illustrate some of the 
Observations. 



The decrease of July 19 being so very 
slight, I for a long time omitted it, and 
took the interval from May to September 
of 116 days as a double revolution, but 
have here preferred the separate ones of 70 
•and 46 days. See Phil. Trans. 1797* 



C The increase and decrease observed by a 
I succession of good observations. 



It thus appears, that the periodical returns of bright- 
ness are uncommonly fluctuating, and that the differences 
between the extremes are very considerable ; to account for 
which, I shall presume to offer the following explanations. 



144 M^' Pigott's Investigation of the Changes 

suggesting previously a few plausible conjectures, and some 
inferences arising from the observations themselves. 

ist. That the body of the stars are dark and solid. 

2d. Their real rotations on their axes are regular. 

3d. That the surrounding medium is by times generating 
and absorbing its luminous particles in a manner nearly similar 
to what has been lately so ingeniously illustrated by the great 
investigator of the heavens, Dr. Herschel, with regard to the 
sun's atmosphere. 

4th. That these luminous particles are but sparingly dispersed 
in the atmosphere surrounding the variable star of Sobieski, 
appears from the star being occasionally diminished to the 6.7 
magnitude, and much less. July 4, 1799, it was of the 7th; 
September 15, 1798, and August 9, 1803^ of the gth, if not 
invisible. (See Table VII. ) Does not this indicate a very small 
portion of light on its darkened hemisphere ? 

5th. And may we not with much plausibility consider them 
as spots, somewhat circular, or of no great extent ? for even on 
its brightest hemisphere the duration of its full lustre is, on a 
mean, only 9^ days of the 62, or about one-sixth and \ of its 
circumference. (See Table VIII. page 140.) The dimensions 
therefore of the parts enlightened seem much circumscribed, 
and can be tolerably estimated, and consequently may be re- 

ft 

presented very small, particularly if the powerful effect of a 
little light and the length of time a bright spot is remaining in 
view be taken into consideration. 

6th. And a further ground of presumption that those principal 
bright parts are but slight patches is, that they undergo perpe^ 
tual changes y and also that such changes are very visible to us, 
for most probably they would be imperceptible, were not the 



oj the variMe Stan in Sobi^ski'^ Shitld. 14^ 

bfi^tparts dontra5ted:by considerable ihter vials or diminiitnanft 
of light r. ! r 

7th, and last. We may obtain some idea of the relative 
situation or intervals between these bright parts, by the observa-. 
tions of the increase and decrease of brightness, as thereby the 
changes and times eiapsed are porateid out. (See Tabjle V. 
page 136.; and Phil. Trans^. for 1797. ) v , 

I have tried practically the efiectof the above siipfiq^itions^ 
by placing small ivhite spot^. on a: daxk. sphere, which. bev!^ 
revolved rounds repnesented the .vai^ibasibhai^es a& nearly raa 
could be' expected :t proceeding tiieref6reinritii i^nse ihd other 
cohsidetratiohs, I shaiU make ideal dralwiitigs of the stajr.with the 
srpall illununated paitsr.sniits^atiiiiosphere^ and apply to/diem; 
some of the actual observations from both the pI'ededu^Tables^ 
having always in view that each period may, more or less, 
require a different disposition of spots, in conseqaevice of their 
cohstant chjaihgeabillty. ' • '^ : . ' ": ^ " ' 

[ Plate tl. Fig; )i,^ A^; the* star 'a p^itAsii^ rduisdiwhic* its 
rofetion t&kes plade in 6^ days from C to D: ' - 

€D/its equator, the i^So deleft bf Xvhich being rettolved 
in 6i' daysi gives n*ai*lyj^ d^gl-eelsi fof eaeh dtfy 's.ftiolion ; the 
brightest 'part or Isfiit' is 'i-epreserijted as qentrally fiicihg us, 
arid accordingly sheyrihgTthe istar in its greatest lustre. Were 
this bright spot and the oth^i-pattfrtcJ reniaih ti/^^»g^i26/^ 
they wottld after haviflg completed AecrevdUtteti q^^Go de* 
grees or '02 days, ^ ( the :$tsr^$^ tt>tiitiow/ on' its' axis, ) appear 
again as at first, and at ^every-ffettiml contintie 'to give exact 
periodical times, as Wa& nearly the Ctt«e4n' 1799 between August 
andXtetober, (^e T^fe IX. p. 14^,) but if the 'spot becomes 

MDCCCV. * U 



ob8Cilre:ahd'<.«i6tfaer b^^ op in ai dif&gMnb pbof^/^iB 
latter will make the star appear at its next full splendour: rfithdr) 
sooner or dtter thabi therrealnttation acccoi^ng to. Ksrpo^itiQny 

.TigciV A f ]|)ill .briglitncssf^disvki^ JK^efij sl^^ bjrlhe game 
spot, it afterwards loses it; light and ranothixi as! br^he is pjxH 
4uced.5day8 modoa:(oit ^ ^degress ^.preoedip^ iti^-EJ aee 
^^. s. ' This Jbtteri-^wfieil) tunBte(l'ceDBtr8lly7t6 the ^intlu wi^lf 
appear: g ^days ^sopmp fthan' l3ie <f odA^^cmfr, now dhsoosed, ( Imkq 
marked P,)^aiDkl ihow. tli&^siktr at it&fidl hts!i^,^makjiig tho 
rotations ^. days. instead; a£€b^ which teai tihe^$e ia I796t tho 
obsciirved reyqlution hetwieai^rSeptcitiibiinjy.Qnd Noyembiet \^^ , 






» » » 



f^i. s. .Wei wall now .apfily a case. of an hitffirval of (oo-gmt 
length, that of 72 days: the spot m alone Jiaying^hewiiusk 
the star in its full lustre, itS; ^ht disappears during the revo- 

lirtiQjDt, and jjwothep fecighltiep^ forth tfip, '4Nffs t( or; 58 .^^[^eqs ) 
follcfwing it at H; ^w ;9 i'9tMni9 to f^ice UB 9£^ h); $» «ii^ra^ 
it beuitg ohlitevtited^ tbei9tar ¥9U fntitU appi^iir/ohscur^, aii4 not 
zfiCDver its si^enfjbur i9>til the new j^ghib^Q^d pjprt H hi^Kx^^ 
c«atral, wMch l^ing fm.^s Utter thsin the positii^ in whic^ 
m was seen, joakes ^e r^volMtioji, 79 days imstead oS 6iii9» 
was ohserv«dibetwoen July t^aoA SepSeipih^r 24, 1801. (See 
Tables IX. ) In the above cuk the altearattons foplii place, whil^ 
beUnd the fitar^ citherwis^ dom^ inregvlartti^s would >h9.ve been 
perceived^ as will Ifiter he noticed. The aame reascmkig with 
proper alterations wUl^ I apprehend* aoooimt for the other re- 
volutions, yet I shall sow^ again, r^ttme the aitgect witi) 



regard to a series of the greatest irregularities ; at present let u* 
proceed to take a few views of the intervals of its least bright^ 
9^5^ 'IvhiblUoontrary: toi my eXpectatiQiii V&^ f^W^ more 
difl^ltio ^xpLftin dismt ^s^ of thesfi^U althq^gh the r^ult^ 
(iisagrbe fess among thcSmaslTefil. The Mrkm^4:> &pe: of th^ 
star is here represented* with it few $mall changealile bright 
spots, placed in gen^eral; ^t .a-ygroper j^stanoe^ se.a$; tQjkieep up 
an iudnterriipted intrease ati4 decreasi^ of i^^t-wk^ regard 
fo us,, and are a}so^,made to con^^spond wittx severd otji^f 

(d>servation!s. ; . ! . ' 

,. A^h Vietv. ,. ,. / , 

J Fig. 4 is to expbia the gjeate^l/ ipferyjil; pf> 74^ daysi 
btttween July 4th, and Septenrfx^ iQ^%T&9^\ (S^TWeX.) 
The darkened hdinispher^/here eX'htbited is its mnimum Jidy 
4th> with liie fdlbwing lspoti^,3c;.ng^ly:^onei€fS(^ next a small 
ode /vthbn. another P of a fmlS^gx ivf^^^^.p;^^^^^ 
day br tvi^o, (-or a few.di^i*6e9») mdr kstly^4il)r^ht|i^ne at JP^ 
jtist al^peffitang. Dudngr the rotation, D loskig its l^t and the 
P ibegdifiing muth brighter, the star at its next retuip in S^ ^yS} 
whrn at ite first p(>^tiofti must (^cQisr^^ app^r. ptuch j}rlght«sri 
(See fig- 5;) fcuti J)yr4hi!ft retirif^:Qf 7 and P.c^ijtinuj^s to dimift 
tu^h^in iiistire t91 f he; ippedSrdit^e. cH" ^^eme large ;spp^frojni th^ 
6tlter hdmibpfaereriwhii^ teking pli^ee. is days laftorwards, 
trail, (wheii thi) tuae is added to the6sf jdready revolved), 
make the lievohitidif of 74 da^s^rdts reqinre^; fcH* a view of a 
sltorl interval, for tiie present let that of. 56' d^yrs he ^ taken, 
between Ai^ust sist and Oetdber 16th 1801. (SeeTableX. ) 






U s 



»48 ^. Pl«?q.TiF'9:ffef«ff%^!(^ (^tl^^^Pmg^ 

p. 4. r 4^» .,. t\'frt V . . ,,^ I »\-, ', .. ,, ' 4.,, .4 ^'>^f^^ *- -f » T .N ..'•...<.. .4 f . ...... .. 

- ",.; '• ' •••A i-i >•■ ■■;•.•"•:' :6'A:f1^./' • ' ■ ■/: ■: - .•./ • * ' . . .•••' 

' ■ Tfeo'teast br%l*tn»fj "fti- tniftkntm fai re|»^ented>ivf figi ^i> 
when the bright sp6ts 'y ind' a: '«t eAch «5ttrfei«ity' trf >th&'equa«» 
toi^i^ diat^e^r'iire' mutually l)uvju^ in sight and a mSmitemiej 
r alonfe on it$ surface preceding^ jf by o dafys motion : i li /are 
other mklcMihg" siz^d sJK)ts <n^iar •>j:,'but* precedihg^ it ; , they 
feahftbt for th6 present be seen- feeiftg on the opposite dr bright 
hemisphere. The spot i dicing ^he stars revolution; having 
lost its light, and r being considerably increased, the next 
minimum will be between tin and n^ (instead of x and j'.) See 
fig: "J ; ' and by the retiring of fi n the diminutiotn of the star's 
light wiH-c6htiiiue'ta %ake iplace only until cth^ riappearailod 
of r, at the place whete jy was, which being 6 da j^s sooner than 
the fdrnier positiort, (See fig. €,^) reduces the rotkidri to '5^ 
days. All fhe^ f<^reg<^g viewciidre from uncoboectedifiejKodsj 
where'ohly t4je ukiihaibe^ r^flrhs df^wJi appearai^ce^haVebeeti 
attended to; • but' now, I sh&ll ex&nwde a l^ngT^fttervftl :wth, 
many intermediate changes^, tfiat- between Jxme : I'&th^ antf 

• • 

September i^th 15^96, wherein are ihdluded the ^ost intricate 
irregularitiiis and vicii^siftides^ : ; th6se ofesefvatlons 'are : already 
printed at full lenglJi in the Phflosophital TfansactioaisrTap 
1797, and therefore cart at any time be' inspected r* indeed^ I 
tiien little thought th^ would ever^becomeoffurther.Ti9e,Tnit 
that of stating facts, t6 which, however, I hirvie always been 
very partial, arid particularly so, after having experieilced the 
advantage of Maraldi's printed observations on the variable 
star in Hydra, as it was partly by them that I ascertained the 
periodical returns of brightness of that star, and which flattered 
me the more, as Maraldi himself had been less successful in 



, ^ihfipidiahle Star in Sobieski's Shield. 14^ 

tl^^attemptj; See WiiL Trans: for 1786. Yet in the present 
Paper I have omitted all such details, being aware they might 
•^ thoi^ht^ too* va}uminous, but hope at some future time the 
Socicjty will honour them with a place in their library. 

The first sketch, Plate III. represents, for June 13, 1796, the 
comparative size of the bright spots supposed to surround the 
star, but here extended at full length ; the next eight following 
are spherical views, on an enlarged scale, for each quarterly 
rotation or less, shewing the principal changes, as expressed 
in the adjoining remarks, and corresponding with the observa^ 
tions ; these being taken from my printed paper, as already 
mentioned, are marked in italics. It will be seen that the spots 
by which the changes are principally regulated, are placed at 
equal distances, yet intermediate ones might also frequently be 
insjeirted without occasioning any objection^ but that of render^ 
yng the epcplanatbns more complex. 



REMARKS ON PLATE III. 

Fig. s. •* ^une \%th. Full brightness Mag. bright sth,*' before 
or after whidh date the star would appear less bright, by the 
spot E being removed from the centre, and one of the others 
out df view. 

Fig. 3. " July Qd, 15 days or ^ rotation being elapsed sincfi 
June i8^fe, 5th Mag. a little decreased"' by the removal of the 
brightest spot £, the h being much less. 

Fig. 4. " July igth, 16 days or i rotation s^ Mag. still de-- 
.creased" N being much less than A, now gone off. A slight 
minimum/' 

Fig. 5. " July ajth^ 8 days of the rotation, 5 Mag. rather 



i;5ro Mr. Pi Gorr's Investigation of the Changes 

increased^' by the considerable increase of "N OTioe four daj^, 
wfth the addition of F, a slight full brightness. 

tig. ^. " Aug. grf, 7 lifljy^ of rotation^ S.€ Mag: ieartasei \tf 
the going off of N, the E, which is now reappearinfg^ being 
reduced to much less thwi F. 

Fig. 7. " Aug. 19th, 16 days or ^ Potation, g.S Mag. agmh 

• « 

decreased," by the removal of F, by E being much less, and by 
the h also being considerably ffiminiished. 

Fig. 8. " Sept. s/i, 15 days or J rotation, 6 Mag. stilt mofi^ 
decreased," by the h being muc^ less than E, which is noi# 
going off, and N scarcely reappearing, another fttinimum. 

^S- 9- " Sept. lyth, 14 days ornear ^ rotation. 5 Mag. full 
brightness considerMy increased," by N having retained its iti^ 
creased brightness of July vj, and now facing us centrally. 
- 1st, Thus are exhibited, the two short intervals 6^ lis foil 
brightness, one between June 18 and Jfaly ^7, of 39 days^ UtA 
the other between July 27 and Sept. 17, of 52 days. See 
Table IX. 

sdly. The interval oif 46 days between the two minima of 
J^y 19 and Sept. 3 ; See Table X. ^ 

gdly, The long decreaise of §8 days betv*«en Jiity «7 aftd 
Sept. 3> 83^^ 

4thly, The rapid increases of 3 and 14 days betwefeft thd t^ 
iand tTtfi of July, Jtod the 3d and 17th o^ September, 

As also tihe ot^r intermediate chartges, 3Fet I itiuM again 
repeat, particularly as a few days ^rf of may dcetision^y "ptth 
ceed from the bbservations, that by thelse sketches it is not 
meant to give exact drawings df the mze, d}£teintes or altseiti^ 
tions of the spots, but merely to shew how the cHartges may 
«ake place, as, I believe, nothing of^ the k&id has luthfrto been 



i^thevariahk Star in Sobibski*s Shield. 151 

ofleir0d'to the public, either with or without cwroborating ob^ 
nervations ; nor do I presume to think, that the explariations 
ai^e the cmly ones or best that can be imagined, the more so^ 
as they solely refer (for greater simplicity) to the star's 
equator, while possibly, were tjie spots placed in a northern or 
southern latitude, or permanent ones near the poles, or were a 
proper inclination, given to the polar axis, they might be more 
satisfactory : however, the materials themselves, the obsena-^ 
tioHs and deductions will I flatter myself ever be acceptable, and 
contiribute to facilitate future conjectures, which from an allow- 
able analogy may extend to similar parts of the starry system, 
wkh regard to the probability of establishing whether any of 
the most irregular or particular changes may not return at fict 
pmodsy or after a certain number of rotations. I think we can 
entertain but slight hopes of it, owing to the great fluctuation, of 
the luminous matter, as shewn by the perpetual varying of the 
apparent revolutions, magnitudes &c. See Tab. IX. X. and VIL 
Still it is natural to suppose, that some parts of the atmosphere 
of this star may have a less tendency than others to become 
luminous, so a& to promote at different times, similar appear^ 
ances ; and indeed this is strongly indicated by the intervals of 
the minima being far more regular than those of the full brightness^ 
which, with other reasons induce ua to suspiect that even one 
of its hemispheres is less favourably constituted or qualified, 
than the other for the generating of these particles, although 
Aey do occasionally encroach on both sides, as appears by the 
observations between June and August, See Phil. Trans, for 
J797, or the eight sketches of 1796, and likewise in 1797, ^^ 
Tab. VII. when during three months it was only reduced to the 
5 or 6 Mag. by which the degree of brightness that surrounded 



15« ^r- PtGOTT's Investigation of the Changes 

ity must have, been nearly equal : had the causes of varying its 
light then ceased, it would ever have continued to appear as an 
unchangeable star of the 5 or 6 Mag. and such is the case of 
several others that/onner/yAov^ been variables^ but for many years 
retain a steady brightness, as (^ Geminorum, i Ursas majoris, 
m Draconis, and perhaps that in the Swan's breast, while others, 
after shewing their changes , have entirely disappeared^ owing to a 
total absorption .of light, as the famous one in Cassiopea, in 
Serpentarius of 1604, that near the Swan's head, and doubtless 
many^more. Does not this induce us to presume that there 
are also others, that have never shewn a glimpse of brightness ? 
Lastly, new variables may become so at different periods, by an. 
unusual and partial increase or diminution of their bright parts, 
as not unlikely was the case of Ceti, Algol » Herculis, Sec. for 
these stars being by times very conspicuous, their changes, had 
they been always equally great, might have been easily noticed 
by the ancient astronomers, who observed only with the naked 
eye. A few lines above, I mentioned the probability that there 
existed primary invisible bodies or unenlightened stars ( if I may 
be allowed the expression) that have ever remained in eternal 
darkness ; how numerous these may be, can never be known. 
Would it then be too daring or visionary to suppose their num- 
bers equal to those endowed with light ? particularly when we 
take into contemplation the ample set of bodies visible only by 
reflected rays, that appertain to our own system, such as the 
planets, asteroides, comets, and satellites. Do not these, al-» 
though but of a secondary nature, lead us to venture on the 
foregoing more enlarged conjecture ; and moreover to suspect, 
that the enlightened stars are those that have already attained 
the highest degree of perfection ? granting, therefore, such 



. of the variable Star in Sobieski's Shield.. r5$ 

multitudes do really exists dusters of them, by being collected 
together 2s in the milky- way, must: intjercept all more distant 
rays, and if free from any intervening lights, they would ap-; 
pear as dark spaces in the heavens, similar to what has bcjen 
observed in the Southern Hemisphere. That so few of these 
obscure places are perceived, may be attributed to their being 
obliterated by the presence either of some scattered stars, or 
of other slight luminous appearances. 

I have thus fully investigated the nature of this distant sun, 
a single one among many millions, and scarcely perceptible 
to the sight, yet of no less importance than our own grand 
luminary. But ours is still supplied abundantly with resplen- 
dent particles, while Sobieski's variable star has them most 
sparingly dispersed over its sphere : a scantiness that apparently 
must occasion to its surrounding planets, constant vicissitudes 
of uncertain darkness, and repletion of light and heat. How 
far more enviable seems our situation ! I mean that which 
we enjoy at present ; there being strong reasons to believe, 
that the sun's luminous appearance has been at times consi- 
derably diminished ; and I have little hesitation in conceiving 
that it may also be reduced at some future period to small 
patches, and then the apparent irregularities of its periodical 
rotations, which at present are only perceived by the obser- 
vations of trifling dark spots, would become evidently conspi- 
cuous, particularly when seen at a distance as remote as the 
variable stars are from us. But such conjectural flights of 
fancy cannot too soon be dropt. I therefore shall conclude 
with observing, that these inquiries on the alterations of light 
of the stars have been so little discussed, that it is to be hoped 
they will not be discontinued ; and although I have already 

MDCCCV. 



154 Mr. Pioorr's Investigation of the Changes^ &c. 

troubled the Society with many papers concerning such 
changes, I nevertheless propose, ere long, having the honour 
of presenting them with one more, most probably my last, oh 
diis subject. 



EDW. HGOTT 



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C 155 3 



yiL An Account of some analytical Experiments on a mineral 
Production from Devonshire, consisting principally of Alumine 
and Water. By Humphry Davy, JE^^. F. JR. $. Professor tf 
Chemistry in the Royal institution. 



'\ 



Head February 98, 1805. 



1, Preliminary Observations. 

Tl { - • * ' 

HIS fossil waa found paany years ago by Dr. Wavel, in a 

quarry ja^ Barnstaple :,,Mr. Hatchett, who visited the place 

in 1;7S|6, desqibed it as .filling some of the cavities and veins 

|n a rop}c' of soft argillaceous shist. When first made known^ 

it was considered as a zeolite ; Mr. Hatchett, however, con- 

V . • Jit ■ 

eluded, from its geological position, that it most probably did 
^t belong to that class of stones ; and Dr. Babington, from 
its physical characters, and from some experiments on its 
solution in acids, made , at his request by Mr. Stockler, ascer- 
tained that it was a mineral body, as yet not described, and 
that it ocmtained a considerable proportion of aluminous earth* 
It is tp Dr. Babington that I am obliged for the opportu- 
nity of making a general investigation of its chemical nature ; 
and that gentleman liberally supplied me with specimens for 
analysis. 



Xs 



J 



156 Mr. Davy's Account of some analytical Experiments 

II. Sensible Characters of the Fossil. 

The most common appearance pf the fossil is in smali 
hemispherical groups of crystals, composed of a number of 
filaments radiating from a,. common centre, and inserted on 
the surface of the shist ; but in some instances it exists as a 
collection of irregularly disposed prisms forming small veins 
in the stone : as yet, I believe, no insulated or distinct crystal 
has been found. Its colour is white^ in, a few cases with a 
tinge of gray or of green,' and in some pieces (apparently 
beginning to decompose ) of yellow. Its lustre is silky ; some 
of the specimens possess semi-transparency, but in general it 
is nearly opaque. Its texture is loose, but its small fragme^iv'? 
possess great hardness, so as to scratch agate. ' : 1 1 jl 

It produces no effect on the smell when breathed upori^ has 

410 taste, does not become electrical of phosphorescent by heat 

« . . • 

or friction, and does not adhere to the tongue till after it hks 
been strongly ignited. It doeS not decrepitate before the ftame 

of the blow-^pipe j but it loses its hardness, and becomes quite 

■ • ■•'.».. 

opaque. In consequence of the hiiriiit6nesS of the portions in 
which it is found, few of them exceeding the size of a pea, it 
is very difficult to ascertain its specific gravity with any pre- 
cision; but from several trials I am dispersed to 'believe, tiiat 

It does not exceed 2,70, that of water being considered as 

• * • ■ • 

1,00. 

III. Chemical Characters of the ^Fossil. ' 

The perfectly white and semi-transparent specimens of the 
fossil are soluble both in the mineral acids and in fixed alka- 
line lixivia by heat, without sensibly effervescing and without 



an a mineral Production Jhm Devonshire. 157 

leaving any notable residuum ; but a small part remains un- 
cUssolved, when coloured or opaque specimens are exposed to 
the alkaline lixivia. 

A small semi-transparent piece, acted on by the highest 
heat of an excellent forge, had its crystalline texture destroy- 
ed, and was rendered opaque ; but it did not enter into fusion. 
After the experiment it adhered strongly to the tongue, and 
was found to have lost more than a fourth of its weight. Water 
and iiloohol, whether hot or cold, had no effect on the fossil. 
When it was acted on by a heat of from 212'' to 600"* Fahrbn*- 
HEiT in a glass tube, it gave out an elastic vapour, which when 
condensed appeared as a clear fluid possessing a slight em^ 
P3nreumatic smell, but no taste different from that of pur* 
water. 

The soluticHi of the fossil in sulphuric add, when evaporated 
sufficiently, deposited crystals which appeared in thin plates, 
and had all the properties of sulphate of alumine ; and the 
9d&A matter, when redis^olved and mixed with a little carbo- 
iiate eS potash, slowly depooted octahedral crystals of alum* 
The solid matter precipitated from the saLatioon of the white 
and s^ni-transpiurent fossil in muriatic acid, was in no manner 
acted ttppn by soludcm of carbonate of ammonia, and therefore 
it could not contam any glodnie or ittria; and its perfect 
solubility without residuum in alkaline lixivia shewed that it 
was^ alumiiie. 

When* the opaque varieties of the fossil were fully ex- 
posedft^the agency of alkaline lixivia, the residuum never 
amounMid td* more than- one-twentieth part of the weight of 
the whole. In the white opaque variety, it was merely calca- 
reous earth, for when dissolved in muriatic add, not in excess^ 



158 Mr. Davy's Account of same analytical Experiments 

k gave a white precipitate when mixed with solution of oxalate 
of ammonia, and did not afiect solution of prussiate of potash 
and iron. 

In the green opaque variety, calcareous earth was indicated 
by solution of oxalate of ammonia : and it contained oxide of 
manganese ; for it was not precipitated by solution of aouno* 
nia ; but was rendered turbid, and of a gray colour, by solution 
of prussiate of potash and iron. 

The residuum of the alkaline solution of the yellow variety, 
when dissolved in muriatic acid, piroduced a small quantity of 
white solid matter when mixed with the solution of the oxalate 
of ammonia, and gave a light yellow precipitate by exposure 
to ammonia ; but after this, when neutralized, it did not afiect 
prussiate of potash and iron, so that its colouring matter, as 
there is every reason to believe, was oxide 6/ iron. • 

IV, Analysts of the Fossil. 

Eighty grains of the fossil consisting of the Whitest and most 
transparent parts that could be obtained, were introduced inta 
a small glass tube having a bulb df sufiident capadty to receive 
them with great ease. To the end of this tube, a small glass 
globe attached to another tube, cotnmunicating with a pneuma* 
tic mercurial apparatus, was joined by fusion by means of the 
blow-pipe. 

The bulb of the tube was exposed to the heat of an Argand 
lamp ^ and the globe was preserved cool by being placed in a 
vessel of cold water. In consequence of this arrangement;, the 
fluid disengaged by the heat, became condensed, and no elastic 
matter could be lost. The process was continued for half all 
hour, when the glass tube was quite red. 



on a mineral Production frwn Tkvonshire. 159 

A very minute portion only of permanently dasftic fluid 
passed into the pneuinatic apparatus, and when examined, it 
proved to be common air. The quantity of clear fluid collected, 
when poured into another vessel, weighed 19 grains, but when 
the interior of the apparatus had been carefully wiped and dried, 
the whole loss indicated was si grains. The 19 grains of fluid 
had' a faint smell, similar to that of burning peat ; it was trans- 
parent, and tasted like distilled water; but it slightly reddened 
litmus paper. It produced no cloudiness in solutions of muriate 
of barytes, of acetite of lead, of nitrate of silver, or of sulphate 
of iron. 

The 59 grains of solid matter were dissolved in diluted sul- 
phuric add, which left no residuum ; and the solution was mixed 
with potash, in suffident quantity to cause the alumine at first 
precipitated again to dissolve. What remained undissolved by 
potash, after being collected and properly washed, was heated 
strongly and weighed ; its quantity was a grain and quarter. It 
was white, caustic to the taste, and had all the propertfes of lime. 
The solution was mixed with nitric add till it became sour. 
Solution of carbonate of ammonia was then poured into it till 
the efiect of deconqx>sition ceased. The whole thrown into a 
^trating apparatus left solid matter, which when carefully 
washed and dried at the heat of ignition, weighed 56 grains. 
They were pure alumine : hence the general results of the 
experiments, when calculated upon, indicated for 100 parts of 
spedmen. 

Of alumine ^- ^ ^ 70 
Of lime - - - 1.4 

Of fluid ... - »6.« 

Loss - • - a. 4^ 



i6o Mr. Davy's Account of some analytical Experiments 

The loss lam inclined to attribute to some fluid remaining 
in the stone after the process of distillation ; for I have found, 
from several experiments^ that a red heat is not sufficient to 
expel all the matter capable of being volatilized, and diat the 
full eifect can only be produced by a sfrong white heat. 

Fifty grains of a very tran;sparent part of the fossil, by bang 
exposed in a red heat for fifteen minutes, lost 13 grains; but 
when they were heated to whiteness, the defidency amiounted 
to 15 grains, and the case was similar in other trials. 

Different spedmens of the fossil were examined with great 
Care, for the purpose of ascertaining whether any minute por- 
tion of fixed alkali existed in them ; but no indications of this 
substance could be observed ; the processes were conducted 
by means of solution of the imaltered fossil in nitric add ; the 
earths and oxides were preciptated from the solution by being 
boiled with carbonate of amn\pnia ; and after thdr separaticm, 
the fluid was evaporated to dryness, and the nitrate of ammonia 
decomposed by heat, when no residuum occurred. 

A comparative analysis of 30 grains of a very pelludd sped* 
men was made by solution in lixivium of potash. This spedmeh 
lost 8 grains by long continued ignition, after which it easfly 
dissolved in th6 lixivium by heat, leaving a residuum of a 
quarter of a grain only, which was red Oxide of iron. The pre- 
dpitate from the solution of potash, made by means of muriate 
of ammonia, weighed, when properly treated, si grains. 

Several spedmens were distilled in the manner above de- 
scribed, and in. all cases the water collected had similar proper- 
ties. The only test by which the presence of acid matter in 
ft could be detected, was litmus paper ; and in some cases the 
effect upon this substance was barely perceptible. 



on a mineral Production found in Devonshire. \6x 

V. General Observations. 

I have made several experiments with the hope of adoer^ 
taining the nature of the add matter in the water ; bttf; from 
the impossibility of procuring imy Considerable quatitky of the 
ibssil, they have been wholly unsuccesaful. It is, however, 
evident^ from the experiments already detailed, that it i^ not 
one of the known mineral adds. 

I. am ifisposed to believe, from the minutetieal of its pmpw^ 
tion, and from the difference of this proportion in different 
cases, that it is not essential to the composition of the stone ; and 
that, as well as the oxide of manganese, that of iron, and the 
lime it is only an accidental ingredient, and on this idea the pure 
matter of the fossil must be considered as a chemical combina* 
tion of about thirty parts of water and seventy of alumine. 

The experiments of M. Theodore de Saussure on the pre- 
cipitation* of alumine from its solutions, have demonstrated the 
affinity of this body for water ; but as yet I believe no alumi- 
nous stone, except that which I have just described, has been 
found, containing so lai^e a proportion of water, as thirty parts 
in the hundred. 

The diaspore, which has been examined by M. Vauquelin, 
and which loses sixteen or seventeen parts in the hundred by 
ignition, and which contains nearly eighty of alumine, and only 
three of oxide of iron, is supposed by that excellent chemist to 
be a compound of alumine and water. Its physical and chemical 
characters differ however very much from those of the new 
fossil, and other researches are wanting to ascertain whether 
the part of it volatilized by heat is of the same kind. 

• Journal de Physique, Tom. LII. p. 280. 
MDCCCV. 'Y 



i62 Mr. Davy's Account of some analytical Experiments j &c. 

I have examined a fossil from near St. Austle, in Cornwall, 
very similar to the fossil from Barnstaple in all its general 
chemical characters ; and I have been informed, that an analysis 
of it, made by the Rev. William Gregor some months since, 
proves that it consists of similar ingredients. 

Dr. Babington has proposed to call the fossil from Devon- 
shire fVavellite^ from Dr. Wavel, the gentleman who discovered 
it ; but if a name fomided upon its chemical composition be pre- 
ferred, it may be denominated Hydratgillite, from uJm^ water, 
and afy$>iXog clay. 



C i«s 3 



VIIL Experiments on JFootz. By Mr. David Mushet Om-- 
tnumcaUd by the Right Hon. Sir Joseph Banks^ K. B. P. R. S. 

Read February 14, 1805. 

Xhe following experiments were made at the request of Sir 
Joseph Banks, on five cakes of wootz, with which he supplied 
me for that purpose. As the cakes, which were numbered 
i» 2> 3> 4> S» were not all of the same quality, it will be proper 
first to describe the 'differences observable in their external 
form and appearance. 

No. 1 was a dense solid cake, without any flaw or fungous 
appearance upon the flat, or, what I suppose to be, the upper 
side. The round or under surface was covered with small pits 
or hollows, two of which were of considerable depth ; one 
through which the slit or cut had run, and another nearly as 
large towards the edge of the cake. These depressions, the 
effects, as I suppose, of a species of crystallization in cooling, 
were c(mtinued round the edges, and even approached a little 
way upon the upper surface of the wootz. 

The cake was a quarter of an inch thicker at one extremity 
of the diameter than at the other, from which 1 infer, that the pot 
or crudble, in which this cake had been made, had not occupied 
the furiiace in a vertical position. Its convexity, compared to that 
of the other five, was second. Upon breaking the thin fin of steel, 
which omnects the half cakes together, I found it to possess a 
very small dense white grain. This appearance never takes 



164 ^^' Mushet's Ej^rifflents on Wootz. 

place but with steel of the best quality, and is less frequent in 
very high steel, though the quality be otherwise good. 

Upon ;exaittiAing ^e hc&sik with attention, I perceived several 
laidnag and minute cells filled with rust» which in working are 
never expected to unite or shut together. The grain other- 
wise was uniformly regular in point of colour and size, and 
possessed a favourable appearance of steel. 

No. 2. This cake had two very different aspects ; one side 
was dense and regular, the otfier hollow, Sfkongy) and protube- 
rant. The under surface was more uftifoftnly honey-corabed 
l!han Ko. 1 ", the cotivttxity in the middle w« greater, but to- 
wards thfe Bdges, particularly on one side, it became flatter. 
The grain exposed by Ijreaking was lwg«r, bluer in coloor, 
and more sparkling than No. 1. In breakings tliefkactore tori 
bat slightly otft:, tind displayed tiie ^me untoimected landnse 
Vith ^rusty surfetes, as wwe observed in No. 1, Benie dieec, 
twt) thm fins of malleable iron projected from the unsound 
*«!fe,'and seemed incorporated wMi the ttia«« of steel thraugh- 
t)tifc To\vlards the -centre of the break, and near to the excres^ 
tence common to all the cakes, groi^ of malleable gratis were 
cBstinctly visible. The same appearance, though in a slighter 
degree, manifested itself in ^ouiotts ^aees tiumighout the 
break. 

No. 3. The upper surface of thas bakectMt^ed seven! 4eep 
pks, which seemed to result from the wattt of premier fluicfit^ 
in (Vision. They differed materially from those des^bed upon 
tlie tonvex sides of No. 1 smd ^, and were of th^ kind that 
\votild materially eflfect the steel in forging. 

The under or convex side of tJris cake jnresented a few 
trystalline depressions, and those Tery small ; the convexity 



Mr. Mushet's Experiments (m ff^oott. \t^ 

itiait greater tiiiais that 6f Na i md s^.the fracture of tho Hn 
almost smooth^ and oeky iikione plaoe exhibited a «tilaU degree 
of tenacity in the act of partjbg. In the middle of the break, 
abotst half an inch of soft steel was evident ; and in different 
spots throughout numerous groups of malleable grains, and 
thin laminae of soft blue tough iron made their ^ppeaftmoe. 

No. 4. Was a thick dense cake possessed of the greatest 
convexity ; the depressfons upon the under side were neither 
-fo large, nor so numerDUs as thote in No. 1 and a^ n<^ did they 
approadi the upper snr£u3e of the cake futth^ than the acute 
edge. This surface had the most evtdmt watks of hammering 
to depress the feeder, or fungous part of the metal» wb^ in 
the manufacturing seems the gate or orifice by which the metal 
descends in the act of gravitation. 

The iMreedc of this' caka^ howeyer fiiVoUraUe aa to. extarnal 
ajppearance, waafsLV from being solid; . Towards the feeder it 
aeeoiyed looae^and crumbly, and much oxidated. The grain 
4i^ided itself intD two dratincA strata; doe of a dense wbttiflh 
colour, the other large and bluish, cojataining a number of small 
apedca of great brilliancy* Several irregular lines of malleable 
jvoh pervaded the mass in various places, which indicated a 
compound too heterogeneous for good steeL 

5th cake. This was materially different in appearance from 
'way of die finrmer. It had received but little hammering, yet 
was smooth and free from depressions, or honey*«omfo on 
lidiih surfaces. The feeder^ instead of being an excrescence, 
i^esented a dsepxxmcsve beautifully orystaUized. 
' in breaking, the fracbnre tore out considerably, but pre* 
Mtttied a very iraogular quality of grain. That towards t]^ 
under surface was small and uniform, but towards the ilst or 



i66 Mr. Mushet's Experiments on Wootx. 

upper surface it increased in size, and in the blueness of its 
colour, till it passed. into the state of malleable iron. 

The break of this steel, though appar^itly soft, was the 
least homogeneous of the whole, and throughout it presented 
a very brilliant arrangement of crystal, which in other steel is 
always viewed with suspicion. 

General Remark. 

Uniformly the ^ain and density of the wootz are homoge- 
neous, and free from malleable iron towards the under or 
round surface ; but always the reverse towards the feeder or 
upper side. 

Remarks in Forging. 

No. 1 . One-half of the cake was heated slowly by an anneal* 
ing heat to a deep red, and put under a sharp broad-mouthed 
chissel with a small degree of taper. It cut with difficulty, was 
reheated, and cracked a little towards one end of the slit or 
cut ori^ally in the cake. 

The heat in this trial was so moderate, that I was afraid diat 
the crack had arisen from a want of tenacity, occasioned by 
the heat being too low. 

The other half was heated a few shades higher, and sub- 
jected to the same mode of cutting; before the cMssel had 
half way reached the bottom, the piece parted iii two in the 
direction of the depression made by the cutting instrument 
The additional heat in this instance proved an injury, while 
the cracking of the steel in both cases, particularly the foriQer, 
was a certain proof of the abundance, or rather of the excess 
of the steely principle. 



Mr. Mushet's Experiments on Wbotz. i6^ 

The fractures of both half cakes, now obtained for a second 
time, were materially different from that obtained by the simple 
division of the cake. The grain was nearly uniform, distinctly 

r • 

marked, but of too gray a colour for serviceable steeL Two 
6f the quarters being drawn into neat bars under hand ham- 
mers at a low heat, one of them contained a number of crack» 
and fissures. The fracture was gray, tore out a little in break- 
ing, but was otherwise yolky arid excessively dense. A small 
bar of penknife size was improved greatly in drawing down, 
and had only one crack in thirteen inches of length. The 
grain and fracture were both highly improved by this addi- 
tional labour; the tenacity of the steel was greater, and it 
stood firmly under the hammer at a bright red heat 

The other two quarters of this cake were squared a little^ 
and successively put under a tilt hammer, of two hundred 
weight, going at the rate of three hundred blows per minute, 
and drawn into small penknife sdze. One of the bars from an 
outside piece, always the most solid, was ^itirely free from 
cracks, and had only one small scale running upon one side. 

These bars exhibited a tougher break, than those drawn by 
hand ; the colour was whiter, and the grain possessed a more 
regular and silky appearance. 

Forging No. «. 

One half of this cake was heated to a scarlet shade, and put 
under the cutting chissel ; it was at first struck lightly, then 
reheated, and cut comparatively soft ; but a small crack had 
over-run the progress of the chissel. Its softness in cutting 
was attributed to an evident want of solidity. The other half 
cake felt harder under the hammer, but proved afterwards 



itSS Mr. Mu&et'^s ExpmiAents nH fFbQtA 

spongy throughout the mass. In th6 act of euttki^i a loose 
pulverized matter Was disengaged from some of the cells, 
possessed of a shining appearance. . 

The fractures obtained in consequence of the division of the 
half cakes, presented a flattish crystallized. appearance, more 
resembling very white cast iron, than steel capable of being 
extended under the hammer. One of the middle cuts was 
entirely cellular with crystallized interiors, and incapable of 
drawing; the correspondinj^ cut of the other half cake was 
drawn into a straight bar three quarters of an kich in breadth^ 
and three^eighths thick, but was covered with cracks and flaws 
from <end to end. The colour of tha break was oiie shade 
lighter than No. i , it tor« less out, was equally yolky, and 
possestei ot) the whole an aspect very unfavourable for good 
steel. JJ i • 

The<:fther two outside cyuarters were also, drawn into shape^ 
ovie uniier the ^It hammer, and thfe 40jthGT by hand. These 
Avere more, soBd in the fracture, possessed fewer surface* 
cracks, stood a holier degrtee of heat, tore out tnbre, and ex- 

r - 

hibited a silky glossy grain, at least tw^o shades lighter in the 
colour than the centre. pieces. 

Forging Qd Cake. 

One half of this cake, first subjected to be cut, was found 
softei* than «iy of the precedmg, and exhibited no symp- 
tom of cracking. The other half was cut at three heats^ 
but found loose and hollow in the extreme. A considerable 
portion of the same brilliant powder, formerly noticed, was 
here again disengaged. It was carefully taken up for exami^ 
nation, and found to be very fine ore of iron in a pnlTeriescefxt 



Mr. Mushet's Experiments on Wootx, iSg 

state, very obedient to the magnet, and without any doubt an 
unmetallized portion of that from which wootz is made. 

This curious circumstance, led me to examine every pore 
and cell throughout the whole fragments. On the upper sur- 
face of two of them I found small pits containing a portion of 
the ore, which had been slightly agglutinated in the fire, but 
still highly magnetic. The upper surface of the present cake, 
close by the gate or feeder, contained a large pit filled with a 
stratum of semi-fused ore, surmounted by a mass of vitrified 
matter, which bore evident marks of containing calcareous 
earth. 

Those who have devoted sufficient attention to the affinities 
of iron and earths for carbon, will be surprised to find that, on 
this particular subject, the rude fabricators of steel in Hindostan 
have got llie start of our more polished countrymen in the 
manufacture of steel. 

Two bars of wootz were formed from this cake, and these 
in point of quality inferior to any of those formerly produced. 
The appearance of the metal was more varied, less homoge- 
neous, and ccmtained more distinct laminae with nisty surfaces^ 
than either of the two former cakes. 

It appeared highly probable, from die observations that oc- 
curred in forgmg, and in the examination of the cake, that the 
original proportion of mixture was such as would have formed 
a quality of steel softer than No. i and s ; but as steel of such 
softness requires a* greater heat to fuse it, than when more 
f<illy saturated with carbonaceous matter, it is probable that 
the furnace. had not been sufficiently powerful to occasicxi 
complete fusion of the whole mass, and generate a steel homo-: 
geneous in all its parts. 

MDCCCV, Z 



170 Mr. Mushet^s ExperitMnts on JFootz^ 

Forging 4ffh Cake. 

Both halves of this cake cut pleasantly, and with a degree 
of tenacity and resistance, mixed at the same time with soft-* 
ness beyond what was experienced in any of tb? former cakes. 
Two quarters of this cake were drawn under the tilt hamnier} 
and one by hand. The resulting bars were nearly perfects 
A slight scale was observable upon the bar, from that quarter 
which contained the figure. The fracture Was solidly thoii^ 
not homogeneous as to quality and colour, and it appeared 
pretty evident, that a considerable portion of one side throng 
the whole bar was^ in the state of malleable iron, and of course 
not capable of beinig. hardened. It was a subject c^ con^ilerT 
able regret, that the cake the most perfect and the most tcata-^ 
cious of thewhol^ in the pix)cej3« of forg^Qf^, should get an 
imperfection which rendered it useless for the perfect purposes 
ofsteeL . 



. < 



first half of thii) cake cut unoommcmty soft lor wootsv 
but by cracking before the chissel still exhibited a Warit of 
proper tenacity^^ Th« n^?ct half cut eqnall^' Soft, iM^ with more 
^beliaeitiy. Two qtMrter^ ^ lihis. cake dt^w readHy. out under 
^ tilt hammekr, and. a; third wais drawn by hand; a^ a farigfat 
red, sometimes approaching to a'faint.whitie heal None.af tha 
bars thus ohiniaed were unifc^cmfy free horn caraidpi:aiHl acak^ 
addiough ^ fiiacture. exhihitBd a faiv break of a ligfat Unil 
colour, and the graifi ivaa distiiactiy madked^ and ficee from 



Mr. Mushet's Experiments (m Wootz. 171 

General Remarks. 

The fcMrmalion of wootz appears to me to be in consequence 
of the fusion of a peculiar ore, pei'haps ^Icareous, or rendered 
highly s6 by tnixture of calcareous earth along with a por- 
tion of carbonaceous matter. That this is performed in a clay 
or other vessel or crucible, is' equally presumable, in which the 
separated metal is allowed to cool ; hence the crystallization 
that occupies the pits and cells found in and upon the under 
or rounded surface of the wootz cakes. 

The want of homogeneity, and of real soli<fity in almost 
every cake of wootz, appears to me to be a dffect consequence 
of the want of heat sufficiently powerful to effect a perfect 
reduction ; what strengdiens this? supposition much is, that 
those cakes that are the hardest, L e. that contain the greatest 
ijuantity of carbonaceous matter, and of course form the most 
fusible steel, are always the most solid and homogeneous. On 
the contrary, those cakes, into which the cutting chissel most 
easily finds its way, are in general cellular, replete with laminae, 
and abound in veins of malleable iron. 

It is probable, had the native Hindostan the means of ren- 
dering his cast steel as fiuid as water, it would have occurred 
to him to have run it into moulds, and by this means have 
acquired an article uniform in its quality, and convenient for 
those purposes to which it is applied. 

The hammering, which is evident around the feeder and 
upon the upper surface in general, may thus be accounted for. 
When the cake is taken from the pot or crucible, the feeder 
will most probably be slightly elevated, and the top of the 
cake partially covered with small masses of ore and steel iron, 



i7« Mr. Mushet's Experiments on Wootz. 

which the paucity of the heat had left either imperfectly sepa- 
rated or unfused. These most probably, to make the jnroduct 
more marketable, are cut off at a second heatings and the 
whole surface hammered smooth. 

I have observed the same facts and similar appearances in 
operations of a like nature, and can account satisfactorily for 
it as follows. 

The first portions of metal, that are separated in experi- 
ments of this nature, contain the largest share of the whole 
carbon introduced into the mixture. It follows of course, that 
an inferior degree of heat will maintain this portion of metal 
in a state of fluidity, but that a much higher temperature is 
requisite to reduce the particles of metal, thus for a season 
robbed of their carbon, and bring them into contact with the 
portion first rendered fluid, to receive their proportion of the 
steely principle. Where the heat is languid, the descent of the 
last portions of iron is sluggish, the mass below begins to lose 
its fluidity, while its disposition for giving out carbon is reduced 
by the gradual addition of more iron. An accumulation takes 
place of metallic masses of various diameters, rising up for 
half an inch or more into the glass that covers the metal ; 
these are neatly welded and inserted into each other, and 
diminish in diameter as they go up. The length, or even the 
existence of this feeder or excrescence, depends upon the heat 
in general, and upon its temperature at different periods of the 
same process. If there has been sufficient heat, the surface 
will be convex and uniformly crystalline ; but if the heat has 
been urged, after the feeder has been formed and an affinity 
established between it and the steelified mass below, it will 
only partially disappear in the Jatter, and the head or part of 



Mr. ytunYi&SViEsi^ermehts mJFoaiz. 173 

the upper end of the feeder will be found suspended in the 
glaiss4:hat covers the steeL ' 

The same or similar phenomena take place m separating 
crUde^ iron -from its ores, when highly carbonated^ and difficult, 
from ah ekcei^ of c^rbon^-cf being fused. - > ^ 
' Thfe division, of the v^6ptz cake by thfe manufacturers of 
Hindostan, I apprehend is merely to facilitate its subse^ttent 
application to the purposes ;0(f *be,. artist ; it may serve at the 
sam<9 time as a test of the- quality -of the.ateel. ! . 

To ascertain, by -direct experiment, whether wootz ow^ its 
Hardness to an vextraquantitgr oT ktarbonV' thp fbUowing expe- 
Hnidtuis w«re p^i/onrie^ pcurtions bf woota of 

common cast steel, and of white crude iron, preimsing tlitt 
in operations with iron and its.oir^, I have always found the 
comparative measure of carbon best ascwrtained by the quan- 
tity T3f lead- which was reduced from flint glass. : . 1 

..^IStCake. , ^^, .Graios. 

Fragments of wootz - ^ - ''^"'''^ - 65 

Pounded flint gl^s ^hree tknes^the weigl^tv - > 195 

This mixture was exposed to a heat. of 100* Wedgewood, 

and the wootz fused into a well crystallized spherule of steel. 

A thin crust of revived lead was found below the wootz,, which 

weighed q grains, or -f^^'the weight of the wootz. 

^d Cake. 
Fragments of wootz - - - "80 

Flint g?ass, same proportion as above - - a^o 

The fusion of the mixture in this experiment wasproducfive 

of a mass of lead weighing 10 griunSi equal to ^th thfe weight 

of the wootz. 



- .^ 



174 Mr, Mushef 8 Expmmentt ote Wootn, 



% 



2fl Cake. Grtiiit. 

Fragments of wootz - - - - 75 * 

Flint glass - - « - . ^ 93^. 

The mass of lead precipitated beneath the steel in this ex<^ 

periment, amounted to 9 grains, or ^^ the wdght of the wootz 

employed. 

j^kCake. 
Fragments of wootz '— -* - * ^ 

Flint glass - '^ - ^ *. 979 

Lead obtained, predpitated from tiie glass by means of th^ 

barbon of the wootz 14! gndns, equal to xi4o ^ wdght of 

the wootz. ' : . 

gthCake. 
Fragments of wdotz •* .^ «- ^ ^ - 

Flint glass - ^ •• - V -, 407 

The lead revived in this experiment amounted to 7 grains, 

which is equal to Yuis ^® weight of the wootz. 

6th. (^t Steel formed with ^h part its freight o/C^^ 

• » » • • • • 

Fragments - - - - - 90 

Crystal glass - ! - - - a 70 

Iiead revived 8^ grains equal to t|^ ^^ weight of the steel 
introduced. 

. . "/th. White cast Iron dropt while Fluid into Water. 

Fn^ments - - - - - 103 

Crystal glass - - • - - 309 

. ' Th« fu^on of this precipitated »s^ iprains of lead which i< 

equal to y^V^ the weight of the cast iron. 



Mr. Mushet's Experiments an Wootz. 175 

Recapitulation of these Experime?its. 

cake of wootz revived of lead - - ,139 

sd ditto ----- ,125 

gd ditto - - - - ,120 

4th ditto ----- ,156 

5th ditto - - - - ,10a 

Steel containing ^ of its weight of carbon - ,094, 

Cast iron ----- ,228 

It would appear to result from these experiments, that wootz ' 

contains a greater proportion of carbonaceous matter, than the 

common qualities of cast steel in this country, and that some 

particular cakes approach considerably to the nature of cast 

iron. This drcumstance, added to the imperfect fusion which 

generally occurs in the formation of wootz, appear to me to 

be quite sufficient to account for its refractory nature, and 

unhomogeneous texture. 

Notwithstanding the many imperfections with which wootz 
is loaded, it certainly possesses the radical principles of good 
steel, and impresses us with a high opinion of the ore from 
which it is formed. 

The possession of this ore for the fabrication of steel and 
bar iron, might to this coimtry be an object of the highest 
importance. At present it is a subject of regret, that such a 
source of wealth cannot be annexed to its capital and talent. 
Were such an event practicable, then our East India Company 
might, in their own dominions, supply their stores with a valu- 
able article, and at a much inferior price to any they send from 
this country. 



' •» 



. i 1 .. 



/ 



• » .. • 



,► ; . ♦ 



PHILOSOPHICAL 



TRANSACTIONS, 



OF THE 



ROYAL SOCIETY 



OP 



LONDON. 



FOR THE YEAR MDCCCV. 



PART II. 



LONDON, 



FKINTED BY W. BULMER AND CO. CLEVELAND-ROW, IT. JAMES*8 ; 
AND SOLO BY G..AND W. NICOL, PALL-UALL, BOOKSELLERS TO HIS MAJESTY, 

AND PRINTERS TO THE ROYAL SOCIETY. 

MDCCCV. 



CONTENTS. 



ea 



• 



IX. Abstract of Observations on a diurnal Variation of the 
Barometer between the Tropics. By J. Horsburgh, jfog. In a 
Letter to Henry Cavendish, Esq. F. R.S. p. 177 

X. Concerning the Differences in the magnetic Needle^ on Board 
' the Investigator y arising from an Alteration in the Direction of 

the Ship's Head. By Matthew Flinders, Esq. Commander of 
his Majesty's Ship Investigator. In a Letter to the Right Hon. 
Sir Joseph Banks, K. B. P. R. S. p. 186 

XL The Physiology of the Stapes^ one of the Bones of the Organ 
of Hearing ; deduced from a comparative View of its Structure, 
and Uses, in different Animals. By Anthony Carlisle, Esq. 
F.R.S. p. 198 

XIL On an artificial Substance which possesses the principal cha- 
racteristic Properties of Tannin. By Charles Hatchett, J^sq. 
E.R.S. - . p. ^11 

XIII. The Case of a full grown Woman in whom the Ovaria were 
deficient. By Mr. Charles Pears, F. L. S. Communicated by 
the Right Hon. &> Joseph Banks, K. B. P. R. S. p. £25 

XIV. A Description of Malformation in the Heart of an Infant. 
By Mr. Hugh Chudleigh Standert. Communicated by Anthony 
Carlisle, Esq. F. R. S. p. 228 

XV. On a Method of analyzing Stones containing fixed Alkali, by 
Means of the Boracic Acid. By Humphry Davy, F^q. F. R. S. 
Professor of Chemistry in the Royal Institution p. 231 



IV CONTENTS. 

XVL On the Direction and Velocity of the Motion of the Sun^ and 
Solar System. B^ WiUiamrHerschely^XI/.D. F.R.S. p. 233 

XVII. OntheReproductionofBuds. By Thomas Andrew Knight, 
Esq. F.R.S^ Li a. L et t e r to the Rigkt Hon., Sir Jj>5ephr Ba&ks# 
K. B. P. R. S. p. «57 

XVIII. Some Account of two Mummies of the Egyptian Ibis, one 
of which zfiof in a r^mffrkably perfect State;, ^y John Pearson^ 
Esq. RR.S. p. ^^4 

%V3^. Observations on, t^, lingular Figuf» of the^ Planet Saturn. 
By WUliaipv B&eroscbpl, hL.JX F.R.S^ p. . a 7A 

XX. On the magnetic Attractiw^ of Oxides of hxm. By Timothy 
Lanej Esq. F, ^, S. p. «8i 

}^X|; AdditiMof Experiments (md\ Hemnnft; on an art^al Sub^ 
stance, zvluch possesses the principal characteristic Properties^ of 
Tannin, By Chafes Hatehett, Esq. F. R. 5. p. 285. 

XXIL On the Disctruery of Palladium ; mi^ Observations on 
obiter Snifitianoes found with PlatimL, By William Hyde 
Wollaston, M.D. Sec. R.S. P- 5^^ 

XXIIL Experiments an a Mineral Sjibdance^formiriy supposed to^ 
be Zeolite;, wthseme Remarks on tzuo Species of Urah^Hmmer. 
J^the Rev. William Gregor. Communicated by Charles 
HatchcstTv Esq. E. Ri Sv p. 331^ 



• - ) 



PHlLOSOfHICAL 



TRANSACTIONS. 



/- • * •» ^ »-> •■ 



f 



IX. Ahstracl ^ p^s«rv^tims m fl ^m^i K^vitigfi of ihf 
Barometer b^mem tii^ Tropic^. By J- jtfer$J?Hrghi ^q, fy. f. 
Lfifter to Hwry <^av.«cidisl), J?j$. F, R.^. 



Rqad March 14, 180^. . 

SIR^ .Bombay, April to, 1304. 

Whbn I was in London ?t :the conclu^iqn pf thp year iSgiji , 
I had the pleasure qf being ia^Qduced .to you by fay ifri^nd 
Nfr. Daiaymfle, at which time h^ jxreseot^d yoi^ jvith ^prae 
sheets of meteqrological pbseryatiops, wi^h barometj^r and 
thermometer, made by me in India, and .d^ifing 9. rP^figc 
from India to England. 

Being of opinion that ie>v jegist^rs of the barometer are 
kept zt sea, especially ^ Ipw latitudes, I have hesn induced to 
coptinue my^hserv^tioflts ;sinqe J left England, Judging 4:h^t, 
even if they w?re jfoiwd to be qfno .utility,. they m^ght^t.lea^t 
be entertaining 40 ypu a^ oth^ ^ntlem^n^ who hftve bee^i 
making observations .of a sin^ilar ;jature. 

During ray ijast voyage I .have emjplqy^ two jnaarine 
MDcccv. A a 



178 Mr, Horsburgh's Observations on a 

barometers, one made by Troughton, the other by Ramsden, 
and a thermometer? by; Fh azer. ^ These were placed exposed 
to a free current of air in a cabin, where the basons of the 
barometers were 13 feet above the level of the sea. 

The hours at which the heights of the barometers, and ther- 
mometers were taken, viz. noon, iv hours, x hours, xii hours, 
XVI hours, and xix hours, were chosen, because'at these times" 
the mercury in the barometer had been perceived to be regu- 
larly stationary between the tropics, by former observations 
Aiade in India in 1800 and 1801. It was found that in settled 
weather in the Indian seaS, from SAM to noon, the mercury 
in the barometer was generally stationary, and at the point of 
greatest elevation ; after noon it began to fall, and continued 
falling till 4 afternoon, at which time it arrived at the lowest 
point of depression. Firohi' iV or \rPM the mercury rose again, 
and continued rising till about ix or x PM, at which time it 
had again acc][uired its greatest point of elevation, and con^ 
tiiriued stationary nekrly till midnight ; after which it began to 

fall, tillat IV- AM it was again as low as it had been at iv after- 

, . . . 

noon preceding ; but from this time it rose till 7 or 8 o'clock, 
when it reached the highest point of elevation, and continued 
stationary tall noon. 

Thus was the mercury observed to be subject to a regular 
elevation and depression twicfe in every 24 hours in settied 
weather ; and the lowest station was observed to be at about 4 
o'clock' in the morning and evening. I remarked that the 
mercury never remained long fixed at this low station, but 
had a regular tendency to rise from thehce till towards 8 
in the morning and about 9 in the evening, and from those 
times continued \3tationary till noon and midnight. 



• diurnal Vyoriation ojtht Barometer between. the Tropics. 1 79 

In unsettled blowing weather, especially at Bombay during 
the rains, these regular ebbings and fk? wings of the mercury 
could not, he perceived ; but ^»i*?^dency to them was at som.e- 
times observable when the weather was .more settled. 

In the sheet;s, which I, formerly .presented to you, were 
evinced these elevations and depressions twice every 24 hours 
within the tropics, in steady weather;,%as. had been observed 
by Mess, CAssANrapd PEYRousJE^rby Dr. Balkoujql of Calcutta, 
and others. But sipce my last arrival in. India, Lhave observed 
that the atmos]^ere appears to produce a different effect on the 
barometer at sea from what it does on shqre. 

As I am ignorant whether this phenomenon has been noticed 
by any person before, I will here give you an abstract, of my 
journal, shewing how the barometer has been influenced 
during the whole time since I left England, which will enable 
you to form an idea whether I am right in concluding that the 
barometer is really differently, affected at sea from what it is 
on shore, at those places in India where the observations have 
been made. 

The first sheet begins with the observations made on board 
ship, in my voyage from London towards Bombay, in the 
months of April and May, iSoa, 

From the time of leaving the Land's End, April igith, the 
motion of the mercury in barometers was fluctuating and irre^ 
gular until we were in latitude 26° N, longitude 20* W, oij 
April 29th ; the mercury in barometers then became uniform in 
performing two elevations and two depressions every 24 hours, 
{ which for brevity in mentioning hereafter I will call equatro- 
pical motions.) From latitude 26* N to latitude 10* N, the 
difFerence of the high and low stations of the mercury in the 

Aa 2 



i86 A^. HoRsBUftGH's Observations on a 

bafdttietets W2te hat so great, as it was from latitude lo** N 
acrdss the dqiiator, and from thence to latitude 25*^ S. Within 
these last-mentioned limits, the differencie of high and low 
stations bf the mercury m the barometers was vefy consi- 
derablie, generally from five to r&ne hund^red parts of an 
inth, both in the daily and nightly motions. 

When we reached the latitude of 28^ S, longitude sty"* W, 
June 7th, the mercury in barometers hb l<5iiger Adhered to 
the equatropical motions ; but then, as in high hbrth latitudes, its 
rising and falling became irregular and fluctuating during our 
run from latitude 28"* S^ longitude 27** W, (mostly between 
the parallels of 35** and 36** S,) tihtil We were in latitude 27° S, 
and longitude 51* E, dn the 11th of Jidy. 'tYte mercury then 
began to perfbrm the equatropical motions, and continued 
therii uniformly, during our run from the last-mentioned po- 
isitioh, \xp the Madagascar Archi{)elago, acrross the Equator, 
until our arrival at Bombay July 3 1st, 1802, 

August 6th, 1802. When the balrometers were placed on 
shore in Bombay, the mercury, for the first six days, appeared 
to have a small tendency towards performing the equatropical 
motions, but not equally perceptible as when at sea, the dif- 
ference between the high and low stations of the mercury in 
^he baromieters being grfeat to the day we entered the harbour 
T>f Bombay. From the 12th of August to the 22d the mercury 
4BofuId not in geherd be observed to have any inclination to 
^pefrfdfm the equatropical motions, akhough at times a very 
^mall tehdtettcy towards performing them might be perceived. 

Oh the 2^d of August the barometers were taken from the 
Siftore to the ship. Ihimediately on leaving Bombay harbour, 
Augtist ^ifh, 1802, the ttietcury in the barometers performed 



diurnal Variation of the Barometer between the Tropics. 181 

fhfi ^quatropical itiotiond, and continued them with great uni- 
tortnity, during our passage dbwn the Malabar coast, across 
the bay of Bengal, in the Strait of Malacca, and through the 
China Sea, until our arrival in Canton river on the 4th of 
Ortober. When in the river, the mercury became nearly sta^ 
tiofnary during the ^4 hours, except a small inclination at times 
towards the equatro{Mcal motions, but they were not near so 
perceptible as at sea ; this chaoige taking place the day we got 
ihto the river. 

During our stay in China, the barometer on shore, at Canton, 
had very little tendency towards the equatropical motions, 
throughout the montlks of October and November that we 
remained there. At times, while in China, a small inclination 
towards performing the e<}uatr(^ical motions appeared : but, 
as in Bombay, the difference of rise and fall was of so small 
a quantity, as to be frequently imperceptible. 

December 2d, 1802. On our departure from Canton river, 
the equatropical motions were instantly performed by the 
mercury, and with great regularity continued during the whole 
of the pasaage to Bombay, until our arrival in that harbour on 
the 11th of January, 1809. 

On January 18th, the barometers were plaoed on shore, and 
drd not appear in the smallest degree subject to the equatro- 
pical motions ; although, whh great regularity, they liad be«n 
performed while at sea, even to the day we entered the harbour. 
One of the barometers was left on board for a few days, and, 
like that on shore, seemed to haye no tendency towards 
the equatropical motions. During the months of February 
Mid March, in Bombay, the mercury wais nearly stationary 
throughout the 24 hours. But about the latter part of Marcl\ 



iB2 Mr. Horsburgh's Observations on a 

the mercury seemed to incline towards the equatropical mo- 
tions in a very small degree ; and, during the mondi of April, 
and to the 20th of May, this small tendency of the mercury to 
perform the motions appeared at times, but was hardly dis?- 
cemible, the rise and fall being of so small a quantity. From 
the 18th of January to the 20th of May, the mercury in the 
barometers was in general stationary, except a very small ten- 
dency towards the equatropical motions at times. At other 
times some change in the atmosphere disturbed the mercury 
from its stationary position ; but this was seldom the case, as 
it was then the fair weather season, or north-east monsoon. 

We sailed from Bombay on the 23d of May, 1803. The 
instant we got out of the harbour, the mercury in the baro- 
meters conformed to the equatropical motions with great 
« 

regularity, and the difference between the high and low stations 
was very considerable during the whole of the passage to 
China, excepting a few days in the eastern parts of Malacca 
Strait, where the land lay contiguous on each side of us ; the 
difference between the high and low stations of the mercury 
was then not so great as in the open sea. On clearing the 
Strait, and entering the China Sea,, the equatropical motions 
were performed in greater quantity, and continued regular 
during our passage up the China Sea, until July sd, 1803, We 
then entered Canton river, and the equatropical motions of 
the mercury in barometers entirely ceased. 

From July 8th to September 7th, the barometers were placed 
on shore in Canton, during which time the mercury appeared 
to have no tendency towards performing the equatropical 
motions ; but it inclined to a stationary position, except when 
influenced by changes of weather. After the barometers were 



diurnal Variation of the Barometer between the Tropics. i8g 

taken from Canton to the ship, we were four days in getting 
clear of the river, in which time the mercury inclined to be 
stationary, excepting that a small inclination towards the equa- 
tropical motions seemed to evince itself at times. But no 
sooner had we cleared Canton river, September igth, 1803, 
than the mercury in the barometers began to conform to the 
equatropical motions, of two elevations and two depressions 
every 24 hours, at equal intervals of time, (although we were 
near the land until the 15th September.) And the mercury, 
with great regularity, continued to perform the equatropical 
motions, from September igth, 1803, the day we cleared the 
river of Canton, until October isth, when we entered Sincapore 
Strait, excepting a small degree of irregularity, which affected 
the mercury on the asd September, when it blew a gale on 
the coast of Isiompa. 

October r3th, 1803. On entering the Strait of Sincapore,, 
which is about 3^ leagues wide, the mercury in the barometers 
was then a little obstructed, and did not perform the equatro- 
pical motions, in the same quantity of rise and fall, as when 
we were in the China Sea. But on the following day, October 
i4,th, when we had passed the narrow part of the Strait, the 
mercury conformed to those motions with regularity until 
October 21st, when we arrived in the harbour of Prince of 
Wales's Island; then a great retardation took place in the 
equatropical motions ; for, during the time the ship remained 
in the harbour, from October 20th to November 5th, 1803, the 
mercury in barometers seemed only in a small degree subject 
to them, the difference between the high and low stations of 
the mercury, being in general not more than half the quantity, 
that takes place in the open sea, or at a considerable distance 



iB4 ^' HQR.fi^uROH's Oheroations on a 

from hxA. Wh^re ^ ship \z^ at this ticae In tijys I^tarbour, 
Uae land, <m one side, was a full quarter of a igjile diftjHit;^ ^ 
on the other side aJknit e^I^ inile. 

Oil NoveBaber ^tfc^ being <flear of the harbour <)f Pmice pf 
Wales's Island, the ^u^itiiopical motions w«re instantly per- 
formed hy the mea'ctiry, in the uaual ^atttky ^xperienqed at 
sea, wh^ich continued with uniiforiajty until December ^. Qn 
this, and the following day, the mercury fell considerably 
d-uring our passage over the tails of the sands at the entcanoe 
of Hoogly river, in latitude ^i"* 06' N ; and ovi December 5th, 
the 4ay of the moon's la§t quarter, a gale of wind commenced 
from NNE^ with miioh lightniiig and rain in the night. During 
die l^ter part of this day, the mercury began to rise, and 
there soon foMowed a change of settled weather. When we 
were in the lower part of the river, the mercury appeared to 
conform in a small degree to the equatropical motions ; but 
when well up the river, at Diamond Harbour, the mercury 
inclined to be nearly stationary during the 24 hours, as has 
formerly been observed to happen in Canton river, Bombay 
harbour, ^c. 

On January 13th, 1804, ^^^^^ we had cleared the river 
Hoogly, the mercury in the barometers began to perform 
its motions with uniformity, which continued duri];\g the 
passage to Bombay, until our arrival there on February isth. 
The barometers being then placed on shore, the m^^cury in- 
clined to a stationary position, without evincing any propensity 
towards the equatropical motions from the i^th to the 18th 
February, 1804, as has been noticed in the foregoing descrip- 
tion, to happen frequently, on entering a harbour from «ea. 

On February i8tb, 1804. The meteorological journal ceases, 



diumal Variation of the Baxxmuter between the Tropics. 185 

at which time it comprises the observations of as monthsi, 
having commenced April 6th^ 1809, in Margate Road. 

I have taken the liberty of sending you this abstract from 
the journal, to exhibit the apparent difference of the mercury 
in the barometerat sea,, from what has been observed on shore, 
at those places mentioned in the preceding description. As I 
have not seen any account indicating the phenomenon, I 
thought it might be interesting to you, or other gentlemen of 
the Royal Society to forward tliis imperfect abstract, the 
journal itself being too cumbersome to send home at present. 
But as^ I am in expectation of returning to England hy the 
ships, from China next, season, I hope I. shall be enabled to 
present you with the meteorological sheets alluded to above. 

I am^ &c. 

J. HQBSBUBGH. 

P. S. Since I wrote the foregoing dbstract,.! haire received 
a IcMer fsont my frieiad Mr. Daieymple^ intimating that a 
c<^ of the metecwological joiin^l itgrelf wcoild' be aGceptaUe, 
>idiieh has induced me to transmit to him the original sheets, 
with a. ntqeest to del^iwr them to you^ I regret that I could 
nolt find kianre tintt to make- out a £air copy,, to have sent. 
t<D you, m pBsbcerirf the oi%inal sheets in. tfieir roughi state; 

June I St, 1804. 



MDCCCV. B b 



Cise:] 



X. Concerning tJie Differences in tJie magnetic Needle^ on Board 
the Investigator y arising from a?i Alteration in the Direction of 
the Ship's Head. By Matthew Flinders, Esq. Commander of, 
his Majesty's Ship Investigator. In a Letter to the Right Hon. 
Sir Joseph Banks, K. B. P. R. S. 



Read March 28, 1805. 

AVhilst surveying along the south coast of New Holland, 
in 1801 and i8o«, I observed a considerable difference in the 
direction of the magnetic needle, when there was no other 
apparent cause for it than that of the ship's head being in a 
different direction. This occasioned much perplexity in laying 
down the bearings, and in allowing a proper variation upon 
them, and put me under the necessity of endeavouring to find 
out some' method of correcting or allowing for these diffe- 
rences ; for unless this could be done, many errors must una- 
voidably get admission into the chart. I first removed two 
guns into the hold, which had stood near the^ compasses, and 
afterwards fixed the surveying compass exactly a-midships 
upon the binnacle, for at first it was occasionally shifted to the 
weather side as the ship went about ; but neither of these two 
arrangements produced any material effect in remedying the 
disagreements. 

The following Table contains the observations for the varia- 
tion of the compass in which the differences are most remark- 
able, and from which I shall beg to point out such inferences 
as I think may be drawn from them. 



Mr. Flinders on certain IXfferences of the magnetic Needle. 187 









Number of 


Number of sets cf 


Pkcoof 


Supposed 


Obicrred 


Ship's 




Time^ 


Latitude. 


Longitude, 


cotnpai^es 


observatioas taken. 


the 


true 


variation 


head. 


Observer* 








ufed. 


, 


compass. 


variation. 








1801. 


t 


/ 






< 


/ 


1 






Dec. AM 


Pnncess Rp] 


116 28 £ 


two 


4 azimuths 


binnacle 


7 oW 


5 S9W 


NWb. N 


Commander 




r^I Harbour 


three 


onshore' 


61$ 


6 ^3 


— 




-« 


-. 


theodolite 


I — 


.— 


-« 


6 8 


•^ 




1802. 






* 


* 
• • 


* ' 










Jan. Q, PM 


34 » 


121 20 


one 


2 — 


binnacle 


5 


9 22 


ESE 




16, AM 


Goose Jslana Bay | 


one 


2 — 


^^ 


4- 


54 


W 




1803. 









. 


• 


■E 








May to, AM 


— 


— « 


• 


2 — 


»- 


% 


6 8 


£ 


• 


1802. 


« 


» 




t ^ 




m 








Jan, 18, PM 


'33 37 . 


,"4 1.0 


— 


2 -.- 


— 


4 30 


5 44 


NNE 




20, PM 


32 33 


»25 3S 


— .' 


a* — 


— 




7 ^5 ' 


Eb.N 




21, PM 


32 30 


125 48 


— . 


2 — 


— 


— 


4 45 


S 




22, PM 


3* 30 


126 7 


.«• 


2 — 


— - 


4 »5 


6 13 


NEb.£ 




23, PM 


32 21 


126 33 




I amplitude 


— 


4 


6 4 


Sb. £ 




24, AM 


32 5 


128 15 


..« 


2 azimuths 


— 


3 <^ 


Eb.N 




26, PM 


•32. .15 


128 15 


, three 


6 _ 


-« 




3 7 


Sb. £ 


Lt. Flinders 


30, AM 


32 18 


132.20 


one 


2 — 


-» 


30 


1 41 


SSE 


Commander 


Feb. 4, AM 


No. 4* bay iii inland e 


■^■^ 


2 — . 


— i 


15 


2 23 


Easterly 




5. AM 


32 39 


133 55 


— 


I amplitude 


— 




1 56 


£ b. S 




6, AM 


•32 36 


>33 58 


three 


6 azimuths 


•^ 


»» 


I £ 


NW 


Lt. Flinders 


16, PM 


34 3 


135 20 


one 


2 -» 


— 


I 5E 


I 33 W 


SEb. £ 


Commander 


— , PM 


34 5 


135 24 


— 


I amplitude 


— 


» 5 


3 56E 


SW 




18, AM 


34 50 


135 32 


three 


6 azimuths 


•» 


I 12 


I 12 


s 


Lt. Flinders 


Mar. u PM 


[n No. 10, bay 


theodolite 


I — 


on shore 


I 39 


' 39 


-^ 


Commander 


5.PM 


.*-. 


— 


one 


2 — 


binnacle 


" 39 


53 


Sb. £ 




17, PM 


34 12 


137 20 


-.. 


I amplitude 


— 


2 15 


4 38 


SWb.S 


Commander 


18, PM 


34 23 


137 36 


one 


2 azimuths 


binnacle 


2 15 


35 


S£ 




21, AM 


35 33 


«37 15 


three 


6 ^ 


— 


2 4o£ 


I 10 


SEb.S 




23. AM 


Kanguroo Island 


two 


4 — 


— 


2 58 


6 31 


SSW 


/ 


26, AM 


35 «o 


137 4> 


one 


I amplitude 


— 


2 45 


1 49 


NEb. N 


r 


27, AM 


35 21 


137 52 


one 


1 — 


— 


2 50 


I 49 


SSE 




April 69 AM 


Kanguroo Island 


— 


2 azimuths 


on shore 


2 58 


2 58 


•— 




10, AM 


35 47 


'39 «5 


— 


I amplitude 


binnacle 


3 


5 " - 


Wb.S 




ii,PM 


35 53 


139 26 


— 


2 azimuths 


— 


3 


50 


SE 




13, PM 


36 45 


140 5 


— 


2 — 


— 


3 30 


1 25 


SEb.S 




16, AM 


37 55 


^39 55 


— 


L I amplitude / 


— 


4 »5 


2 20 


— 




17, PM 


37 57 


139 56 


— 


2 azimuths 


— 


4 ^5 


2 2 


NE 




22, AM 


39 38 


144 50 


— • 


2 — * 


— 


7 45 


II 52 


WSW 




26, PM 


38 35 


144 25 


*— 


2 — 


— 


7 30 


3 4» 


NEb. £ 




— ,AM 


38 38 


>44 35 




I amplitude 


■^w 


7 30 


6 48 


NEb. N 


' * 



Note. All the compasses made use of on board the Inyestigator were of Walksr's construction, one excepted^ . 
which was made by Apams, and used only oj July 22d^ i8qi. 



Bba 



tfiS Mr. FLi\Na>BR's m.i€&iam i!^efwc» 

It is apparent that some of the observed variation fi m 4he 
above Table are 4* less and dtheirs 4^ greater than the truth ; 
and it may be remarked, that when this lerror is westward, 
the ship!^ Ihead was east> or nearly s(o, and when it was east- 
ward the head was in the epposite ^iredtion. When the 
observations agree nearest with wTialt was taken on shore, or 
with what may be deemed the true variation, the ship's head 
waJs nearly north or south ; and a minute inspection of the 
Table will favour the opinion, that the excess or diminution of 
the variation was generally in proportion as the chip's head 
inclined on either side from the magnetic meridian. 

Aftef % had well ascertained the certainty of a difference in 
die compasses, arising from an alteration in the point steered, 
I judged it necessary, when I wanted a ^fet of bearings from a 
'point where we tacked the ship, to take one set just before and 
another immediately after that operation: some specimens of 
these here follow. 

Head £S£« Mead SW b. W. 

1802. April 13th r Lc Ocographe Rocks, N 55** to 71® E 

II* 32', AM< «point . - N 4 W . after tackiii|; N 9»W 

— [npoint - - S 32 £ - - • S 40 E. 

H§ad S£ b. E. Head W. 

April 14th in pomt rocky, inner part N 39® E - - :after tacking* N 30* £ 
5^ 29', AM /— — - projecting part N67E - - - -N59E 

— Farthest visible extreme from 

deck • - -S51E • • . -Ss^E. 

A^aiENE. ifr^rfSWb. 6. 

.April i;tb In, the western .part - N I5*W • - after taofcing, N i-i* W 

11*^ 50', AM jA peaked hummock -N19E • -• N15E 

— Jnrthesr extreme from deck .S53'E •• • • S61E 

— Centre of a naked sandy patch •£. . . * EjN. 

Variation per amplitude April 15, AM, 7 o j,' i? •k;«»« 4««** 4«.;««. « 
taken with the surveying compass C "^ ^ ^' ^^'P ^ ^"^ ^"^^ ^' 

Head E. 2Ie4id SW b. S. 

April » 5th, 7 The peaked hummock - N .1 2^ W - after tacking, N iS* W 
5** PM \ Former extreme, a {projection S59E - - S64E 

— Naked sandy patch, distant 3j'N33E - - - N3i£. 



6f the magnetic Needle. 1 8^ 

From ficmie Idtfile change of place alter tacking the ship, and 
from the part who6e bearing was set not being perhaps the 
HiAvidual spot in both instances^ ^tibe difiference between the 
separate bearings in any set will not be always tiie same : to 
these causes for ^rror also may be added inaccuisffcies in taking 
the angles arising from the motion cif the ship and compass^ 
from the view of the object Ibeing obstructed by the T^ging, 
masts, or ship's upper works, and irom too much haste rto get 
the bearings before the ship's place was materially altered. 
Even in the Table of azimuths and amplitudes greater accuracy 
than one degree must not be looked for ; and in ship-bearings 
ft or even 3 degrees is not, I believe, too great an allowance 
for error, unless in very favourable circumstances. 

Without attending to small differences, it is evident that the 
bearings correspond with the observations in requiring a l^^s 
east variation to l>e applied when the ship's head was easterly, 
and a greater when it was to the westward, in order to get at 
the true direction of the object.* When examining the norfli 

^ A%z specimen of the pltn I followed in protracting such bearings at the above, 
take the set of April i$» AM, when the true variation appears to have been 4*^ K. On 
the first bearings the ship's head was six points on one side of the meridian, and on 
the second it was three poiifts on the other side, the mean is one point and an half 
on the east side ; now for this one point and an half I allow 'i^ of ef ror, which, as it is 
on the ettst skleof themeridian, and the variation is easterly, must be subtracted : the 
variation then to be allowed upon the mean between the hearings before and after 
tacking Will be 3^ E» from wliich the true bearings will stand as follows : 
April 15th, AM in western part * - - - N I5°£ 

11^50^ J A^pctd^edhimiiaooli * - ^ - .N^o E 

M«. Fartheat extivme fram^deok *- ^ - 8 ^4 -fi 

•^ Centre of a naked sandy pQCtch - - £ d| 6. 

In diesamcmanner upon smgle sets of bcavings I was obliged 'to all6w a vH^iiitioR 
diflgrent iirom what I. supposed the true to bd« unkss the ship's head was nearly nofth 
or south : but^ that I might proceed as littk upon conjecture as possible, I always 



n 



190 



M7\ Flinders on certain Differences 



and east coasts of New Holland, I always endeavoured to take 
the angles on shore with a Troughton's portable theodolite, 
and to observe for the variation in the same places, that all the 
errors might be done away or corrected ; and as I was fre- 
quently fortunate enough to carry on my surveys in this 
manner for weeks together, instances that might corroborate 
or contradict the preceding remarks are neither very numerous 
or pointed ; the following are the most remarkable. 









Number of 


Number of 


Place of 


Supposed 


Observed 


Ship's 




T\mt4 


Latitude. 


Loogitude. 


coropatset 
used. 


sets of observa- 
tions taken. 


the 
compass. 


true 
variatioD. 


variation. 


head. . 


Observer. 


1802. 


1 


/ 








/ 


/ 






Aug. 5, PM 


23 SI s 


151 42 E 


one 


I amplitude 


binnacle 


8 o£ 


12 7E 


wsw 


Commander 


— AM 


23 51 


151 40 


— 


— 


— - 


— 


10 15 


WNW 




12, PM 


23 30 


151 II 


three 


6 azimuths 


... 


.._ 


6 50 


SSE 


Lt. Flinders 


i8>PM 


23 23 


151 16 


one 


2 — 


— 


7 45 


7 52 


W 


Commander 


31 


22 23 


150 38 


two 


4 — 


•^ 


7 30 


4 49 


£ 




Sept. 6, AM 


Upon Pier 


Head 


theodolite 


I — 


on shore 


8 


8 2 


^ 




Oct. I4» PM 


20 44 


150 42 


one 


I amplitude 


binnacle 


7 


6 40 


SSE 


Lt. Flinders 


20, PM 


19 22 


148 40 


r— 


I — 


-— 


6 


5 39 


S 


Commander 


2i> AM 


18 15 


148 38 


three 


6 azimuths 


— 


•^ 


5 42 


Nb. E 


Lt. Flinders 


Nov. 2, PM 


10 30 


14* 32 


one 


2 — 


.-« 


4 ^ 


3 3^ 


E 


Commander 


7, AM 


12 II 


142 


— 


2 — 


— 




4 4 


S 


Lt. Flinders 


9*PM 


12 37 


142 2 


_ 


I amplitude 


— 


— 


■ 1 

5 H 


w 


Commander 


1803. 




















Jan. 3, PM 


14 20 


136 16 


— 


I — 


— 


2 30 


58 


E 




7, PM 


14 20 


136 37 


— 


I — 


_ 


— 


» 9 


SE 




I4» AM 


J3 38 
Ini^V^ Bay 


137 20 

(Gr. EyL) 
Bay 


— • 


2 — 
I — 


— 


3 


3 47 
5 5" 


Westerly 
WSW 


Lt. Flinders 
Commander 


itf, PM 


theodolite 


I azimuth 


on shore 


.-I. 


36 


— 




Feb. 3» AM 


ArnhemS 


three 


6 — 


binnacle 


2 20 


2 26 


NWb.W 




9, AM 


«M 


— 


theodolite 


I — 


on shore 


•« 


2 20 


... 




Mar. io« AM 


" 5 


134 «S 


one 


2 — 


binnacle 


I 


» 55 


WNW 





endeavoured to get observations for the variation when the ship's head waa in the 
same direction as when I had taken or wished to take a particular set of hearings^ and 
I then allowed that variation exactly, whatever it was. The perplexity arising from 
disagreements in bearings was by these means much alleviated, and happy agreements 
were frequently produced* when* without sucb corrections^ there was nothing hut 
discord. 



of the magnetic Needle. . ^ 191 

In the latter of these observations, the cfiflferences arising 
from a change in the direction of the ship's head is less consi- 
derable than in the higher latitudes; indeed, oYi approaching 
the line of no variation upon the south coast, the differences in 
the variation were smaller than before and afterwards ; but that 
these differences shall be greater in a large variation and smaller 
in a less, both places being equally distant from the magnetic 
pole, I will not venture to assert. The inferences that I think 
may be safely drawn from the above observations are as fol- 
lows : 1 St. That there was a difference in the direction of the 
magnetic needle on board the Investigator when the ship's 
head pointed to the east, and when it was directed westward. 
«d. That this difference was easterly when the ship's head was 
west, and westerly when it was east. 3d. That when the ship's 
head was north or south the needle took the same direction or 
nearly so that it would on shore ; and shewed a variation from 
the true meridian, which was nearly the medium between what 
it showed when east and when west. 4th. That the error in 
variation was nearly proportionate to the number of points 
which the ship's head was from the north or south. Constant 
employment upon practice has not allowed me to become much 
acquainted with theories, but the little information I have upon 
the subject of magnetism has led me to form some notion con- 
cerning the cause of these differences, and although most 
probably vague and unscientific, I trust for the candour of the 
learned in submitting it, as well as the inferences above drawn, 
to their judgment. 

1st. I suppose the attractive power of the different bodies in 
a ship, which are capable of affecting the compass, to be col- 
lected into something like a focal point or center of gravity. 



J 



igt9 Mr. FuKStERs m certain Differences 

and that ihiA pomfl is nearly in the center of the fthip^ where the 
shot are deposited^ for here the greateist. quantity of ircHi is col*- 
lected together. 

dd. I suppose this point to be endued with the same kind of 
attraction as^ the pole of the hemisphere where the ship i^i 
consequently, in New Holland the south end of the needle^ 
would be atts!acted by it and the north end repelled. 

$d. That &e attractive power of this point is sufficiently 
strong in a ship'of war to interfere with the action of the mag<- 
isstic poles upon a compass placed upon or in the binnacle.. 

if diese suppositicxis are consistent with the laws of mag- 
netismt, established by experiments, I judge that they will 
account for all the differences above noticed ; for the interfe- 
rence will necessarily be most perceptible upon a compas& 
when, the* attvactive- point is at right angles to the magnetic 
mendiait, ^ueb is^ when the ship's head is east or west, and will 
altogether vsmish or become imperceptible when the attractive 
point and mendian coincide, or wh^i the ship's head is^ north 
o9 sooth. That fix pc^ver of t^is point should become less as. 
dtt ship increases her distaiice from the ms^pietic pole has not 
indeed entered into my suppositions ; but it may j^baUy be 
true, and is indeed almost a necessary consequence of the 
second supposition. If the above hypothesis> so to call it, be 
true, it ransfi foilow,. that die differences in the variation, of the 
magnetic, needle,, arising from at change in the ship's h^d, 
ought to be directly eontraary to those before recited, when the 
ship is on the north side of the magnetic equator,, for the 
nor^ point of the needle shoiidd then be attracted, and 
the swAh end repelledi. I have no* observations which are very 
dedaixe' upon ^bi^ head,, but those that were taken on board 



of ih magnrtic I^ilk. ' i^ 

the Investigator seem to bespeak that it is so; thej are as 



■k 



Time. 



Ltdtttde. 



Lon^tado. 



ofcom- 



ttted. 



Nuffiher of 
sets of obur- 
vattont taken. 



Place of the 
eempast. 



X 



■««■ 



SappoB- 
cd irnc 
tttria- 
tion. 



^M*i*aM 



Observed 
vsriaciott. 



**MMM 



Ship's 
head. 



Obterrer« 



iSoi. 
Julyai, PM 

22«PM 

— ,AM 
s8, PM 

3~PM 

Aug. 24, AM 

29, AM 

Sept. 5t AM 



Start Point m sight 
to tbe N£ 



49° 10' N 
48 15 
38 I 



5*25* W 
14 20 



Porto Santo in sight 
to Hie NW 

10 20 22 15 

5 40 r6 30 

2 15 14 00 



two 
on/: 
two 
one 
five 

two 

one 
two 



$ stztmuths 
f amplitude 
4 azimuths 
t amplitude 

10 azimuths 

11 . — 

4 — 

4 — 

2 — 

4 — • 

a • — 



bmnsde 



the y 

ship J 



r Dpon the 
J booms *~ 

X of the ship 

binilac)# 

boom 
binnacle 



I 



«9 34 W 

29 30 
24 12 

H49 
20 57 

P5' 54 

22 45 

19 51 
12 45 

12 18 

H 54 



W 

wnW 

W&W 

sw 



SEb.S 

wsw 



Mr. Thistle 



Commander 
Mr. Thistle 

Jommander 
Lt. Flinders 
Mr. Thistle 



Tliese observations, particularly those of July t8^ seem to 
be decisive in showing that the variation is more westerly 
when taken upon the binnacle of a ship whose head 4s west- 
ward in north latitude, than when observed in the center of 
the ship, which is a strong confirmation of the suppositions 
before given ; but the observations on the change of the ship's 
head are too few to be satisfactory. 'Almost every sea officer 
can tell whether he has observed the variation of the compass 
to be greater when going down the English Channel than 
when coming up it : and indeed it wotdd be very easy for a 
ship lying in harbour to ascertain tlie point beyond controversy. 
ShcMild this point be well established, I think it would follow, 
that from a high south latitude where the diflferences are great 
on one side, they are most likely to decrease gradually to the 
equator, and to increase in the ssaae way to a high north lati-* 
tude, where they are great on the other side ; thus the smaller 



MDCCCV. 



Cc 



194 -^^- Fi-iNDERs on certain Differences 

differences on the north coast of New Holland will be accounted 
for. I shall leave it to the learned on the subject of magnetism 
to compare the observations here given with those made by 
others in different parts of the earth, and to form from them 
an hypothesis that may embrace tlie whole of the phenomena : 
tlie opinion I have ventured to offer is merely the vague con- 
jecture of one who does not profess to understand the subject. 
Some account of the magnetism of Pier Head, upon the east 
coast of New Holland, may not perhaps be thought an unap- 
propriate conclusion to this Paper. I was induced to attend to 
this from the following passage in Hawkesworth, Vol. III. 
p. 126. " At sun-rise I went ashore/' says Captain Cook, " and 
" climbing a considerable hill,"" Pier Head, " I took a view of 
** the coast and the islands that lie off it, with their bearings, 
" having an azimuth compass with me for that purpose ; but I 
" observed that the needle differed very considerably in its 
" position, even to thirty degrees, in some places more, in 
" others less ; and once I found it differ from itself no less 
" than two points in the distance of fourteen feet.* I took up 
" some of the loose stones that lay upon the ground, and 
'* applied them to the needle, but they produced no effect; 

* In a set of angles taken near the head of Amhem north bay, on the west side of 
the gulph of Carpentariaj I found the needle of the theodolite had been drawn 50* from 
its proper direction. The shore consisted of grains of iron ore caked into a stony 
mass ; and a piece of it, when applied to the needle, drew it 6 or 8 degrees from its 
direction, but it then swung back to its error of 50^ where it was stationary. In 
Arnhem south bay a small piece of similar stone drew the needle of the theodolite 
entirely round, yet the bearings taken in this place did not show any disagreement 
from the variation and bearings taken in the neighbouring places^ where the stone did 
not produce any such effect. In most places on shore> where I had occasion to take 
angles, it was my practice to try the effect of a piece of the stone upon the theodolite* 
in order to detect the presence of iron ore« as wdl as on account of my suri:ey. It 



of the magnetic Needte. fgg 

** and I tWeforc concluded tfiat there was iron ore in the hilk, 
^ of which I had remarked other indications, both here ' and 
" in the neighbouring parts." 

On landing at Ber Head I found die stones lying on the 
surface to be porphyry, of a dark bluish colour ; but although 
I understand this spedes is usually found to possess some 
magnetic power, a piece did not produce any sensible effect 
upon the needle of the theodolite when applied. to it. In the 
following observations the theodolite always stood about four 
feet from the ground, thai being nearly the length of its legs. 
I first took an extensive set pf bearings from the top of the 
hill, amongst which were two stations whence Pier Head had 
been before set. The first, called Extensive Mount, distant 34, 
miles, differed from its back bearing 4*" 35' to the right, and 
the second, island a, distant 29I- miles, differed 4"" 45' the same 
way. I now moved the theodolite three yards to the westward, 
and the same two objects bore 2° 10' to the right of their back 
bearing ; on moving it three yards to the south-eastward from 
the first place, they differed »° to the left ; and on moving the 
theodolite four yards to the northward, the same two objects 
bore 1** 10' to the right of their back beaiings. On the fol- 
lowing morning I determined to try the magnetism more par- 
ticularly. Taking the theodolite and dipinng-needle, I landed 
upon the shore of the Head, whence the top of the hill bore 
N 50"* W, about one-third of a mile. The variation of the 
theodolite in this place I observed to be 8"" a' E, and the 

commonly happened that no effect was apparent, but yet I could not trust implicitly 
to the angles^ (particularly on the main land,) unless observations for the variation 
were taken before the instrument was moved, or I had a back bearing of some station 
where such observations had been made. 

Cca 



igS Mr. Flinders m certain Differences 

inclinadon of the south end of the dip{»tig needle 50"* 50^ the 
needle stood vertical when the face of the instrumeiH w^s 
S 2** £• I then took the following bearings : Extensive Mount 
loS"" 30'; tiie same exactly a;3 by back bearing. Double Peak 
143'' 90^; from henoe T rowed round the Head, and landed 
on a rods:, whence the top of the hill bore SSW one^aixth of 
a mile ; Extensive Mount bore ild" 14% the inclination of the 
dipping-needle 50^29', and the needle stood vertical when 
the instrument faced S 3^ E. Thus the difierence was i^"" ia 
the horizontal, and ^"^ in the vertical direction of the needle. 
Ascending the hill, I made the . following observations an the 
top: Extensive Mount 113* so\ a island 133^ 5*', Double 
Peak 148*" 3a' ; the inclination of the needle was 53"* 20', and 
it stood vertical at S 3* E. The cfiflferences here are 5*" 10' in 
die horizontal, and d"* 30' in the vertical direction, from what 
tlie needle stood at in the first morning's place. On moving 
ten yards SSE, the bearings were. Extensive Moimt 108"* 44% 
Double Peak 143* ^5'; the inclination was g^"" 18', and the 
needle was vertical when the instrument faced S 5^ W. fn this 
4th set of observations, the horizontal direction of the needle 
is only a few minutes different from the first place, but the 
vertical direction Is 1* a8'. From the top of the bill I now^ 
moved twenty yards to the north-eastward, when Extensive 
Mount bore 110% Double Peak 144'' 4^'; the inclination of the 
dipping needle was now 50" 35', and it stood vertical at S 3** W. 
Thus it appears that the polarity of the nvagnelic needle i& 
most interrupted at the top of the hill, both according to 
the theodolite and dipjmg-needle. Whether this may arise 
from some particular magnetic substance lodged in the heart 
of the hill, or from the attractive powers of all the substances 



of the magnetic Needle. 197 

which compose Pier Head being centered in a similar point to 
what I have supposed to take place with all the ferruginous 
bodies lodged within a ship^ I shall not attempt to decide. The 
greats differences in the horizontal direction of the needle 
observed by Captain Cook^ might have arisen from his using 
a common azimuth compass, which was probably not fiirther 
elevated from the ground than to be placed on a stone. 

MATTHEW FLINDERS. 

Isle of France, 
March 5tb, 1S04. 



C 198 3 



XL The Physiology of the Stapes^ one of the Bones of the Organ 
of Hearing ; deduced from a comparative View of its Structure^ 
and Uses, in different Animals. By Anthony Carlisle, Esq. 
F.R.S. 

Read April 4, 1805. 

Anatomical descriptions of the mechanism of the eye have 
importantly contributed to the advancement of optics, a branch 
of science which has conferred numerous benefits on mankind. 
Whether a more intimate knowledge of the structure of the 
organs of hearing may illustrate the doctrines of acoustics, 
and thus become a source of similar advantages, can only be 
determined by future investigations, and experiments. The 
following is an attempt to exhibit a part of the instrument of 
hearing, taken from several orders of animals, with an inten- 
tion to shew the office it holds, and the relation it bears to 
other parts of the auditory mechanism. The minuteness of 
this research will not require any apology to that learned 
Body, who for a long series of years have witnessed the de- 
pendance of all the systems of natural knowledge on simple 
particulars, well chosen, and applied to the establishment of 
general laws. 

Doubtless the whole organ of hearing is an apparatus to 
collect occurring sounds, and to convey them to the seat of 
that peculiar sensation, regulating their intensity, or facili- 
tating their progress, according to the degree of impetus. In 
these respects the ear resembles the eye. 



L 



Mr. Carlisle on the Physiology of the Stapes. 1^9 

The ossicula auditus in man, and in the mammalia, form a 
series of conductors, through which sounds are transmitted, 
from the membrana tympani, into the sensitive parts of the 
organ. The number, forms, and relative junctions of these 
ossicles are various ; but, in all cases, their office seems Umited 
to the conveyance of sounds received through the medium of 
air; because fishes have no parts corresponding with them. 
In two classes of animals, the aves, and amphibia, of LiNNiEus, 
one bone, in the situation of the stapes, is the only ossicle of 
the tympanum : in all other animals it is placed next to the 
seat of sensible impression, and most remote from that part of 
the organ on which sounds first impinge. 

The ossicula auditus are formed of bone, resembling that of 
teeth ; it is close in texture, and brittle : in the growing state, 
composed of a vascular pulp, the ossification of which is com- 
pleted soon after birth ; and, like the teeth, they cease to grow 
after that process is finished. The malleus and incus are 
hollow, and possess an internal periosteum; and the whole 
series is covered by a reticular membrane which has no red 
blood-vessels in the adult. It has been asserted by many 
authors that fat, or marrow, is contained in these bones, but I 
am induced to attribute their occasional greasy appearance to 
transudation from the neighbouring parts, during the stage of 
putrefactive maceration, seeing that all such bones when taken 
from recent subjects, are free from the marks of ^t. Although 
density seems to be a requisite condition, yet it is convenient 
that the bones should not be massive, as their figures and rela* 
tive adaptations evidently show. 

The malleus is united to the n>embrana tympani throughout 
half its long diameter, by a process called manubrium ; its. 



afoo Mr. Carlisle on the Physiology of the Staptf^^ 

detached end forms a rounded enlargeiiient, which is articu- 
lated by a sort of hinge joint to the body of tlw mcQs. Three 
mtrscles are fixed to the malleus, the most powerful of whidi 
draws the manubrium, and membrant tympani perpendicnkrly 
inward; the next in strength is ins^erted upon a slender 
stem of bone which forms a right angle with the manubnum, 
and dn the plane of the membrana tympani. The smallest 
muscle is fixed to the processus Iflajor, pulling the malleus 
backward, and pressing its head against the joint of the incus. 
These muscles are all restricted in their actions to the changes 
produceable on the membrana tympani, because the strong 
connections of the joints between the malleus and incus, and 
the incus and stapes, admit of little motion ; indeed the former 
joint is deficient in many animals. The incus has no muscles, 
and forms only a passive intervention between the malleus 
and stapes, which last bone has a peculiar muscle appropriated 
to itself. Hence it appears, that the first series of ossicula 
auditus has a different office from the stapes, as will be subse- 
quently explained. 

The bone, to be now particularly considered, has been called 
stapes, staf&, stapha, or stapeda, from its resemblance to the 
stirrup of a saddle. It was first observed about the middle of 
the sixteenth century; and Philip ab Ingrassias, Realdus 
Columbus, and Bartholomaus Eustachius, have contested 
the honour of its discovery. 

The human stapes is JL of an inch in height, and ^3 in 
width at its basis : it weighs, when dried, y^ of a grain. 

It is divided into the following parts, viz. 

The capitulum, or articulating head, which joins the os 
lenticulare. 



Mr. CARU«i£i M the Physhlcgy cfthe Stapes. soi 

The coUuiTii which unites the capitulum to the two aura. 
And ' 

The bQ^9, on which the expanded crura re&t and terminate. 

The capitulum stapedis has a shallow, concave surface^ to 
receive the os lenticulare, or epiphysis connected to the long 
l^g of the iftcua. ( Vuk Plate IV. letter c. ) Around this joint 
a strong membrane is applied in the manner of a capsular 
ligament. The capitulum is seldom placed exactly on the top 
of the Gothic arch formed by the crur^, and the cms imme- 
diately under the stapedeus muacle^is always the thickest, and 
most curved. ( Vide letter a.) 

The collum is hollow, being only a thin shell of bone ; on 
its side is a small tubercle, to which the tendon of the stape- 
deus muscle is affixed. See letters a and b. 

The crura are curved, and their interior surfaces are groofved, 
leaving only a thin osseits plate. 

The basis is exactly adapted to the the fenestra ovalia, 
more properly called fenestra vestibuli by modern anato* 
mists, and the two ends project beyond theenini. The uj^r 
surface is generally concave, the under surfoce sHghtly convex; 
and here a rising IxHtier marks the msertion of Ae membrane 
which connects it to the edges of the fenestra vestibuli. Vick 
letter c. The outline of the basis somew^ resembles a long 
semi-ellipsis, one side being nearly straight, and the other 
ccmvex. This .figure appears adapted to the expansion of the 
basis, without increasing the bulk of the bone, whilst it gives 
leverage to the muscle. 

When the stapes rests cm its basis, with the straight side 
next to the observer, if the more curved leg be toward the 
left, then it is the stapes of the right ear ; but if on the right, 

MDCCCV, D d 



«02 Mr. Carlisle on the Physiology of the Stapes. 

then it is the left stapes. The arch above the straight side of 
the basis is more rounded than that above the curved side ; the 
latter being an intersection of two curves hke the Gothic arch, 
I. have never seen that expansion of membrane across this 
arch, described by Du Verney ; and, from the great number 
of ears which I have attentively examined, am induced to think 
that a pellicle of mucilaginous fluid, which often covers the 
recent bone, has been mistaken for a membrane. 

The stapes stands perpendicular to the plane of the mem- 
brana tympani; a plane drawn through the crura, parallel to 
the length of the basis^ equally bisects the cavity of the 
tympanum. 

The stapedeus muscle arises within a special cavity in the 
petrous portion of the temporal bone ; it is a short, thick mass 
of red fibres, covered by fascia; and sends forth a round 
tendon through a small osseous aperture at the point of the 
pyramidal eminence, which unites to the collum stapedis in an 
angle of 50 degrees, toward a line drawn perpendicular to the 
plane of the basis, and obliquely across its convex side, in an 
angle of 5 degrees from the bearing of its straight side. The 
action of the stapedeus muscle is to draw the capitulum down- 
ward, and toward the curved side of the blsis. This oblique 
motion depresses the end of the basis under the curved cms, 
whilst it rotates the incus upon its short leg, and presses its 
articulation with the malleus into closer contact : but the stapes 
is not withdrawn from under the long leg of the incus, being 
prevented by the strong connecting ligaments. 

The smaller angle of the tendon crossing the parallel of the 
crura over the convex side of the basis, necessarily depresses 
that edge, the straight side acting as a hinge. The extemus 



Mr. Carlisle on the Physiology of the Stapes. 203 

muscle of the malleus rotates the incus back again, and restores 
it to its passive perpendicular situation; becoming on such 
occasions the antagonist of the stapedeus. It is worthy of 
remark, that all the muscles of the ossicula auditus act nearly at 
right angles, or in straight lines, contrary to the ordinary 
course of muscular application, by which their forces are com- 
paratively augmented. 

The varieties in the human stapes are few : they appear in 
the relative curvature of the crura, and in the degree of slen- 
demess or symmetry of its general form. 

The fenestra ve^tibuli admits the basis of the stapes to 
pass into the vestibulum, when the connecting membrane is 
destroyed, there being no other obstacle to its descent. 

None of the external similitudes in form, nor any corre-: 
spondence in the habits, or voices of animals, appear to govern 
the configuration of these ossicles, except in those mammalia 
inhabiting the waters, such as the seal, walrus, and whale, 
tribes,* where the stapes is always more massive : but in the 
otter, which only dives occasionally, the stapes does not vary 
from that of the fox. In the tiger, dog, and other ferae, the 
crura are straight, meeting in an acute angle ; but the same 
figure occurs in the horse, beaver, goat, and many more her- 
bivorous quadrupeds ; so that no inference can be drawn from 
these different habits of life. 

In the cete, exemplified in the Plate by the porpoise, whose 
organs of hearing precisely resemble those of whales which 
I have seen, and agree with the descriptions of others by Pro- 
fessor Camper, the muscle of the stapes pulls the capitulum 
at an angle of 45 degrees, with the plane of the basis, so as 

* I have not had an opportunity of examining the ossicles of a hippopotsimus* 

Dd2 



204 ^' Carlisle on the PhysUdogy qf the Stapes, 

remarkably to depress its subjacent eiid into the fenestra 
vestibuli; besides the thickness of the basis^ and its exact 
adaptation to the fenestra, exhibit a joint of considerable 
motion. In those animals there is only a small perforatiOTi, 
instead of the crural arch.. Vide letter n.* 

I have discovered a very remarkable singularity, -in tradng 
the comparison of this bone, in the marmot, and Guinea-pig. 
The stapes in these animals is formed with slender Crura, con- 
stituting a rocmded arch, through which an osseus bolt passes, 
so as to rivet it to its situation. This bolt I have named pes^ 
suhis. Vide letter /• It is placed near the top of the arch, so 
that by the action of the sta^deus muscle the upper part of 
the straight crus is brought into contact with the pessu/us; 
and by iiAs mean^s the ^deprfessioh of the basis is limited. It 
does not seem obvious for what further ^d this provision is 
des^ned, because, exceptir^ the shrill whistle, there is nothing 
peculiarly different in the habits of those miinials from othets 
which arc destitute of sudh mechanism. 

Hfie kanguroo has this bone like the correspondii>g osade 
in birds, called Cohimelk; but it has also the malleus and 
incus, which birds have not. 

In the om]thorh3mchifis paradoxus, and ornithorhynchus hys- 
trix, the resemblance Id the oolumelk is still more striking ; 
and forms an additional point of similarity between these 
strange quadn^ieds tmd birds. Their columellse are not, how- 

• The stapes of the seal has Solid rcninded crura> and a small apertnre; that of the 
wttlins is entrrdy solid» afrd the ediges as weH as th« plane of the sides, are a little 
twisted^ agreeing wkh fhc observation of M. Cvvisr« Logons d*Anaiomie comfar^i» 
Tome II. p. 5Q5. In all these aquatic mammalia the fenestra rotunda, called also 
fenestra cochks^ is large^ being three or four diameters more than in other animals 
of similar bulk. 



Mr, CarusLe on ihe Physiology of the Stapes, 265 

evefi articulated to a cartilage, as in birds ; but to a small 
bcme performing the office of the manubrium of the malleus. 

In birds, a slender bone passes to the fenestra vestibuli, 
from a cartilage iixed to the membrana t^ympani : it is called 
columella, having received that name from Julius Casserius. 

Th^e capitulum of the colimiella in birds is slightly expanded, 
and is joined to an obtuse^angled triangular plate of cartilage, 
"vvhich I have called cartilago columellae, (vide letter t,) the 
longest side of the triangle is attached to the membrana 
tympani. In some species of birds a small foramen occurs in 
the middle of this plate, but in many others it is entire. 

A strong muscle is inserted into the shorter angle of the 
cartilage, which draws it downward, and thus ekvaftes the 
opposite angle .in the center of the mentbrana tympani, so as 
to render it conical externally. Two lateral ligaments steady 
the articulation of the cartilage with the head of tiie columella. 

The columellas in birds are less brittle than the ossicula 
auditds in the mammalia ; their bases are 'exactly fitted to the 
fenestra vestibuli ; and that part of those columellas nearest 
the base is generally of a reticulated texture. 

The amphibia are provided with cdiumellae, m their form 
and adaptations resembling those of bkrds: the cartilage is 
here, however, united to the under i^orface of the true skin, 
without any apparcsnt application of musdes to alter its tension. 
The substance of the columella is ev^ less hard than in birds ; 
and its basis is considerably smaller than the fenestra vesti- 
hwli. The cavity of tJie t3rmpanum has no lateral cells, and the 
Eustachian tube is short, and wide, seiemingly for the purpose 
of receiving soimds conveyed through the ftieditim of air. 

From the evidence of these facts, together with the com- 



2o6 Mr. Carlisle on the Physiology of the Stapes. 

parative view exhibited in the Plate, I am led to the following 
conclusions. In man, and the most numerous orders of the 
mammalia, the figure of the stapes is an accommodation to that 
degree of lightness which, throughout the series of ossicles, 
seems a requisite condition. It is also a conductor of vibrations 
in common with the other ossicles : but most especially it is 
designed to press on the fluid contained in the labyrinth by that 
action which it receives from the stapedeus muscle, and the 
hinge-like connection of the straight side of its basis with the 
fenestra vestibuli ; the ultimate effect of which is an increase 
of the tension of the membrane closing the fenestra cochleae. 

It does not appear that any degree of motion ever subsists 
between the ossicula auditus as wholes, which bears any 
relation to the peculiar vibrations of sounds ; but rather that 
the different motions of these bones only affect the membrana 
tympani, and alter the degrees of contact in their articulations, 
so as to influence the intensity of violent impulses ; sounds of less 
impetus, not requiring such modulation, are transmitted through 
the conducting series by the vibrations of the integrant parts 
of these bones, unaccompanied by muscular action. 

This reasoning is suggested by the columella in the aves 
and amphibia: and as many birds are known to imitate a 
variety of artificial sounds with great accuracy, it may be in- 
ferred that they hear such sounds as acutely, and with the 
same distinctness as mankind. 

It seems that all the muscles of the ossicula auditus are of 
the involuntary kind, and the peculiar stimulus to their action 
is sound. The chorda tympani, which supplies them, is a gan- 
gKated nerve: if this supposition be true, then the muscles 
should be considered as all acting together^ and it is well 



• Mr. Carlisle on the Physiology of the Stapes. 207 

known that persons who hear imperfectly are more sensible 
to sounds in a noisy place, as if the muscles were by that 
means awakened to action. 

The office which the basis of the stapes holds, and which 
the stapedeus muscle is especially destined to perform, seems 
to throw considerable light on the use of the cochlea. It cannot 
be allowed that the pressure of the watery fluid in the labyrinth 
is a requisite condition to produce the sensation of hearing, 
since all birds hear without any mechanism for that purpose, 
but as such pressure must ultimately give increased tension to 
the fenestra cochlear, it follows that we inquire at this part 
for the principal use of the stapes. 

As the membrane of the fenestra cochleae is exposed to 

the air contained within the cavity of the tympanum, it appears 

adapted to receive such sounds as pass through the membrana 

tympani, without exciting consonant motions in the series of 

ossicula auditus. 

Experiment. 

My head being laid on a table, with the meatus auditorius 
extemus perpendicular to the horizon, my friend, Mr. William 
Nicholson, pulled the tragus toward the cheek, and dropped 
from a small vial, water, at the temperature of my body, into 
the meatus. The first drop produced a sensation like the report 
of distant cannon, and the same effect succeeded each follow- 
ing drop, until the cavity was filled. 

In this experiment the vibrations of the membrana tympani 
must have been impaired, if not wholly destroyed, by the 

« 

contact and pressure of the water; yet the motions of the 
whole membrane, from the blow of each drop of water, affected 



9o8 Mr. QAXii$ni QH ihg Physiology (fthi Stafus, 

the air captained in the tympanum aufficiently to. produce a 
sensible impression. 

That something like this occurs in many kinds of sounds is 
more than probable ; and as ^e cochlea coijisists of two hollow 
half cones, winding spirally, and uniting at their apices, it fol- 
laws that the sounds affecting either the cone terminating in the 
vestibulum, or that which forms the fenestra cochlear, must 
each pass from the wide to the narrow end ; jmd the tension 
of the parts, in either case, will necessarily aid the impression. 

I have already trespassed beyond the usual limits, and must 
reserve the more ample details of this subject for a work 
expressly directed to the anatomy aad physiology of the 
organs of hearing. 



Explanation of Plate IV. 

a, The left* stapes of a human ear magnified two dia- 
meters; presenting the curved edge of the basis, and the 
more elevated and pointed arch. 

b, The opposite side of the same stapes, shewing its rounded 
axch* 

c, Two figures, the uppermost being the articulating sur* 
£ice of the capitulum, and the one beneath shewing the under 
surface of the basis, of the same stapes. 

d, Staphs of a hedge-hog, (Erinaceus Europausy) magnified 
four diameters. 

e, Stapes of a mole, ( Talpa Europaa^) magnified six times, 
/, Stapes of the musk ox, (Bos moschatus,) twice magnified 

• Th^ other stqiedes aoe all from Ac right ears. 



Mr CARtrsiE on the Physiology of the Stapes. 209 

gy Stapes of the elephant, ( Elephas maximusy) natural sizCt 

hy Stapes of the tiger, (Felis Tigris^) twice magnified, 

/, Stapes of the dog, ( Cams familiaris , ) three times mag- 
nified. 

J, Stapes of the horse, (Equus Cabalius,) twice magnified. 

k. Stapes of the pig, (Sus Scrofa,) three times magnified. 

/, Stapes of the marmot (Arctomys Marmota) with its pes- 
sulus, magnified four times. 

m, Stapes of the seal, (Phoca vitulma^) twice magnified. 

n. Stapes of the porpoise, (Delphtnus Phoa^naj) twice mag- 
nified. 

0, Stapes of the walrus, (Trichechus rosmaruSy) natural size. 

/>, Stapes of the kanguroo, (Macropus Kanguroo,) four times 
magnified. 

q, View of the under surface of its basis. 

Sy Columella of the duck-bill, (OmitJiorhynchus paradoxus^) 
magnified four times. 

r. Basis of the same columella. 

ty Columella and cartilago columellas of a goose, (Anas 
AnseTy) twice magnified. 

Uy Columella of the Egyptian ibis, (Tantalus IbtSj) taken 
from a mummy, three times magnified. 

Vy Columella of a turtle, (Testudo Midas,) natural size, with 
its cartilage. 

Wy Columella of the Gangetic crocodile, (LacertaGangeticay) 
natural size. 

Xy Columella of a turtle, (Testudo coriacea,) natural size. 

yy Columella and cartilage of a frog, (Rana temporariay) 
twice magnified. 

z. Columella of a toad, (Rana BufoJ twice magnified. 
MDcccv. E e 



210 Mr. Carlisle on the Physiology of the Stapes. 

•The third and last lines of objects in the Plate, exhibit the 
outlines, and under surfaces, of the bases of the stapedes, and 
columellas, immediately above. In some, the surface is convex, 
in others concave, Jbut neither the one nor the other are con-- 
stant attendants on any common affinity. 



jyiiios Tmns.^tDQCCM.FlaUlVp Xii?. 




A.iu**€W/r 



C «" 3 



XII. On an artificial Substance which possesses the principal cha- 
racteristic Properties of Tannin. By Charles Hatchett, Esq. 
F. R. S. 

Read April 85, 1805. 

The discovery of the principle on which the effects of 
tanning essentially depend, may be partly attributed to Mr. 
Deyeux, who obtained a substance from galls which he con- 
sidered as a species of resin,* but which was afterwards 
proved by Mr. Seguin to be that which renders the skins of 
animals insoluble in water, and imputrescible, and thus to be 
the principle by which they are converted into leather, -f- 

The chief characteristic property of this substance was 
ascertained by Mr. Seguin to be that of precipitating gelatine 
or glue from water in a state of insolubility, and as it was evi- 
dently different from any vegetable substance hitherto disco- 
vered, he gave it the name of tannin. 

This discovery of Mr. Seguin at once unveiled the theory 
of the art ; an easy and certain method was afibrded by which 
tannin could be detected, and its relative quantity in different 
substances be determined, whilst the nature and properties of 
this newly discovered vegetable principle could be subjected 
to accurate investigation. 

* M/moire sur la Noix d4 Gaile, par M. Dbtiux ; AnnaUs deCbimie, Tome 
XVII. p. 23. t ^i^' Tome XX, p. 15. 

£ e s 



413 Mr. Hatchett on an artificial tanning Substance, 

The former has derived elucidation from the experiments- 
of Mr. Biggin,* and much has been contributed in every 
respect by Mr. PRousT,-f but the subject has received the 
greatest extension and some of the most valuable additions 
from the ingenious labours of Mr. Davy, particularly the 
discovery of the important fact, that catechu or terra japonica 
consists principally of tannin* J 

The united results of the experiments made by these and 
other eminent chemists, appear therefore to have fully esta- 
blished, that tannin is a peculiar substance or principle which 
is naturally formed, and exists in a great number of vegetable 
bodies, such as oak-bark, galls, sumach, catechu, &c. &c. 
commonly accompanied by extract, gallic acid, and mucilage. 

But no one has hitherto supposed that it could be produced 
by art, unless a fact noticed by Mr- Chenevix may be consi- 
dered as 5ome indication of it. 

Mr, Chenevix observed, that a decoction of coffee-berries 
did not precipitate gelatine unless they had been previously 
roasted ; so that tannin had in this case either been formed or 
had been developed from the other vegetable principles by 
the effects of heat. § 

Some recent experiments have however convinced me, that 
a substance possessing the chief characteristic properties of 
tannin may be formed by very simple means, not only from 
vegetable, but even from mineral and animal substances. 

* Phil. Trans. 1799^ p. 259. 

f Annates de Cbimit, Tome XXV. p. 225, Ibid, Tome XLI. p. Jji. Ibid. 
XLIL p. 89. I Phil. Trans. 1803, p. 233. 

\ Nicholson's Journal for 1802, Vol. IL p« ii4. 



Mr. Hatcrett on an artificial tanning Substance, 215 

§11. 

In the course of my experiments on lac, and on some of the 
resins, I had occasion to notice the powerful effects produced 
on them by nitric acid, and I have since observed, that by long 
digesti(m, almost every species of resin is dissolved, and is so 
completely changed, that water does not cause any precipi- 
tation, and that by evaporation a deep yellow viscid substance 
is obt^ned, which is equally soluble in water and in alcohol, 
so that the resinous characters are obliterated. 

When I afterwards had discovered a natural substance, 
which was composed partly of a resin similar to that of recent 
vegetables, and partly of asphaltum,* I was induced to extend 
the experiments already mentioned to the bitumens, in the 
hope of obtaining some characteristic properties by which the 
probable original identity of these bodies with vegetable sub- 
stances might be farther corroborated. In this respect I 
succeeded, in some measure better than I expected; but I 
observed a very material difference between the solutions of 
the resins and those of many of the bitumens, such, for in- 
stance, as asphaltum and jet. The first effect of nitric acid, 
dunng long digestion with these substances, was to form a 
very dark brown solution, whilst a deep yellow or orange 
coloured mass was separated, which by subsequent digestion 
in another portion of nitric acid was completely dissolved, and 
by evaporation was converted into a yellow viscid substance, 
equally soluble in water and in alcohol, so as to perfectly 
resemble that which by similar means had been obtained from 
the resins, excepting, that when burned, it emitted an odour 
somewhat resembling that of the fat oils. 

* Phil, Trans. i8o4> p. 385. • 



ft 14 Mr. Hatchett oh an artificial tanning Substance. 

It therefore appeared to me, that the first or dark brown 
solution had - been formed by the action of the nitric acid on 
the uncomhined carbonaceous part of the bitumens, or that by 
which they are rendered black, and that. the deep yellow 
portion which was separated, was that which constituted the 
real or essential part of these bituminous substances. This 
opinion was confirmed by some experiments which I purposely 
made upon amber, and having every reason therefore to 
believe, that the dark brown solution obtained from asphaltum 
and jet was in fact a solution of coal, I repeated the experi- 
ments on several varieties of the pit or mineral coal, from all 
which, I obtained the dark brown solution in great abundance ; 
but thosfe coals, which contained little or no bitumen, did not 
yield the deep yellow substance which has been mentioned. 

In each experiment I employed lOo grains of the coal, 
which I digested in an open matrass with one ounce of nitric 
acid diluted with two ounces of water. ( The specific gravity 
of the acid was i .40. ) 

After the vessel had been placed in a sand-bath, and as soon 
as it became warm, a considerable effervescence attended with 
much nitrous gas was produced ; after about two days I com- 
monly added a second and sometimes a third ounce of the add, 
arid continued the digestion during five or six days, or until 
the whole, or nearly the whole, was dissolved, excepting in 
those cases when the deep yellow substance was formed ; for 
this I constantly separated. 

The next experiment was made upon charcoal, which was 
more readily dissolved than the preceding substances, without 
leaving any residuum ; the solution was perfect, and the colour 
was reddish-brown.* 

* 

♦ The solubilhy of charcoal in aitric acid, and some of its properties when thus 



Mr. HatcheTt on an artificial tanning Substance, 215 

Having thus by means of nitric acid obtained solutions from 
asphaltum, from jet, from several of the pit-C9als, and from 
charcoal, I evaporated them to dryness in separate vessels, 
taking care in the latter part of the process to evaporate very 
gradually, so as completely to expel the remainder of the 
acid without burning the residuum ; this, in every case, proved 
to be a brawn glossy substance, .wluch exhibited a resinous 
fracture. 

The chemical properties of these residua were as follows, 

1. They were speedily dissolved by cold water and by 
alcohoL 

2. Their flavour was highly astringent. 

3. Exposed to heat, they smoked but little, swelled much, 
and afforded a bulky coal. 

4. Their solutions in water reddened litmus*paper. 

5. The same solutions copiously precipitated the metallic 
salts, especially muriate of tin, acetite of lead, and oxysulphate 
of iron. The colour of these precipitates was commonly browny 
inclining to that of chocolate, excepting the tin, which was 
blackish-gray. 

6. They precipitated gold from its solution, in the metallic 
state. 

7. They also precipitated the earthy salts, such as the 
nitrates of lime, barytes, &c. &c. 

8. The fixed alkalis, as well as ammonia, when first added 

dissolved^ liave been noticed by Professor Lightens tb in in Grill's Chemical 
Annals, 1786; by Mr. Lowitz ; (Crbll*s Chem. Journal* translated into English,. 
Vol. II. p. 255;) and by Mr. Jambson, in his Outline of the Minendogyof the] 
Shethud Islands^ 5(C. 8vo. edit. p. 167. 



ai6 Mr. Hatchett on an artificial tanning Substance. 

to these solutions only deepened the colour, but, after some 
hours, rendered them turbid. 

Q. Glue or isinglass was immediately precipitated by these 
solutions from water, and the precipitates were more or less 
brown according to the strength of the solutions. The pre- 
cipitates were also insoluble in cold and in boiling water, so 
that in their essential properties they proved similar to those 
formed by the varieties of tannin hitherto known, with the 
difference, that this factitious substance appeared to be exempt 
from gallic acid, and mucilage, which commonly accompany 
the varieties of tannin, and which occasion modifications in the 
colour and appearance of some of their precipitates. 

Having thus had the satisfaction to discover that a product 
resembling tannin could be formed by such a simple method, 
not only from vegetable but also from mineral coal, I was 
induced to examine how far the same might be extended to 
animal coal, and I therefore reduced a portion of isinglass 
to that state in a close vessel, and having rubbed it into fine 
powder, I digested it with nitric acid in the manner which 
has been described. At first the acid did not appear to act 
upon it, but at length it was slowly dissolved excepting a small 
quantity, which however was in every respect unchanged; 
and here we may remark, that as animal coal is incinerated 
with much more difficulty than vegetable coal or charcoal, so 
was the same difference to be observed, when oxygen was 
presented to these bodies in the humid way, 

. The solution resembled those which have been described, 
excepting, that the brown colour was more intense^. It was 
evaporated to dryness, and was then dissolved in distilled 



Mr Hatchett on an artificial tanning Substance. 217 

water, after which, the solution being examined by the re- 
agents which had been employed in the former experiments, 
was found to produce similar effects, excepting some diffe- 
rence in the colour of the precipitates. 

I next added some of the liquid to a solution of isinglass, 
and obtained a copious precipitate. Thus it is evident, that 
a tanning substance may be formed from animal as well as 
from vegetable and mineral coal ; and it is not a little curious, 
that this enables us to assert as a matter of fact, although not 
of economy, that one portion of the skin of an animal may be 
employed to convert the other into leather. 

In the course of these experiments, I also subjected coak to 
the action of nitric acid, and obtained a product which re- 
sembled that which had been afforded by pit-coal ; but in this 
case ( as might be expected ) there was not any appearance of 
the deep yellow substance which has so often been men- 
tioned. 

These experiments therefore prove, that a tanning, substance 
may be artificially formed by exposing carbon to the action of 
nitric acid ; and it also appears, that this is best effected when 
the carbon is uncombined with any other substance excepting 
oxygen. The following experiments seem to corroborate this 
opinion. 

1 . A piece of Bovey coal, which had perfectly the appearance 
of half-charred wood, was reduced to powder, and was digested 
with nitric acid until the whole was dissolved. 

The colour of the solution was deep yellow ; and, by eva- 
poration, a yellow viscid mass was obtained, which was 
dissolved in distilled water. This solution was then examined 
by various re-agents, and particularly by gelatine, but not any 

MDCCCV. F f 



ti% Mn. HAXCMBtT on Oft artificial tanning Substance^ 

vestige of taiEnttng matteir could be discovered^ and the pm^ 
^nuxtant substance apipearedl to^ be oxalic acidx 

s. Aijotibier piece of Bovey coal, which had less, of tiie' cha^ 
racters of wood, and was. more perfectly carbonized, was 
treated in the way wjiich has been described ; the solution was 
browni, and, unlike the former, aflbrded a considerabie pred*-* 
pitate with gelatine. 

3- A portion of the first sort of Bovey coal was exposed to^ 
a. ved heat in a close vessel, and: was^ then reduced to powdsp 
and digested with nitric acid; here a remarkable difi^rence' 
was to be observed, for nearly, the whole was- thus coilverfjiscl 
into tiie tannings substance. 

4. A coal from Sussex, extremely like the second sort ofi 
fiovey coal, alsoaffbrded the same product. 

5« A inece. of the Surtiirbrand^ fn3m Iceland yield»ii a similar 
r-esult. 

6. Some deal saw-dust was digested with the nitric acid until 
it was completely dissolved ; by evaporation a yellow visdd 
mass . was obtained, the solution of which^ in water afibrded 
i>esults.like those of the first experiment on the Bovey coal^ 
for oxalic add was found^ in it, but not' any of the tanning 
substance. 

7. Another portion of the same deal saw-dust was converted 
into charcoal in a dose vessel; the charcoal was then treated 
in the manner already described, and was thereby formed into 
a liquid which copiously precipitated gelatine. 

8^* Having, previously ascertained that teak wood dods not 
contain gallic add nor tannin, I reduced some of it into chm*- 
coal^ which was afterwards readily converted into the substance 
above mentk>ned 



Mr. Hat<:h£TT on an artificial tanning Subiiance. 919 

In these experim^its, the deal and the teak wood hdd been 
reduced to the state of coal, as usual, by fire, but as this doea^ 
not appear to have been the means generally employed by 
nature to convert organized substances into the varieties of 
mineral coal, I for a considerable time, previous to the dii^o- 
very of the artificial tanning product, had been employed in a 
series of experiments on the slow carbonization of a great 
number of vegetable stibstances by the humid wHy. 

The agent whicdi I most commonly ti^ed to produce this 
effect, was sidphnric add occasionally diluted ; and dhhough 
many of the processes were extrraoely unpleasant and tedious^ 
yet I have not any reason to regret the time which has been 
thus employed* The subject however i foresee will branch 
out into sereral details, none of which as yet I can regard m 
suffidently com|rfeted to mterit tiie hondur of being sabmkteMl 
to this learned Sodety ; but I aim m a maimer almost compelled 
in the present case to antidpate a few of the experiments^ 
w^ thdr resdfei) because iStn^y are ititimaieafy comijected with 
die subject now under cofisideratione 

in these experiments^ I have observed that concentrated 
sulphuric acid, when poured upon any of die resiftons s&b^ 
stances reduced to powder, dissolved diem in a few minutes ; 
at diis period the solution was transparent, commonly of a 
yellowish-brown colour, and of the condst^icy of a visdd oil. 
Butif, aft^ this, the vessel was placedon a sand^bath>the colot» 
of die solution became piDgressively darker, sulphureous gas 
was evolved, and at length die whole appeared like a very 
thick liquid of an intense black. I purposely for the present 
pass over many phenomena,< some of which are peculiar to the 
€Ufi^:ient aidntances when thus treated, whikft others ^a^ 

Ff a 



220 Mr. Hatchett on an artificial tanning Substance. 

general, and may be referred to those attendant on etherifica- 
tion, for my intention here is only to notice, in a concise 
manner, such as immediately tend to elucidate the subject of 
this Paper. 

When concentrated sulphuric acid is poured on the common 
turpentine of the shops, it almost immediately dissolves it like 
the solid resins ; and if a portion of this solution be poured into 
cold water, the turpentine is precipitated in the solid brittle 
state of common yellow resin. But if a second portion of the 
same solution, after the lapse of an hour or more, be in like 
manner poured into cold water, the resin thus formed is not 
yellow but dark brown ; and if four or five hours are suffered 
to elapse before a third portion is poured into water, the resin 
is found to be completely black. After this, supposing the 
digeistion to be carried on during several days, or until there 
is no longer any productiort of sulphureous gas, the turpentine 
or resin will be found converted into a black porous coal^ 
which, if the operation has been properly conducted, does not 
contain any resin, although a substance may frequently be 
separated by digestion in alcohol, which I shall soon have 
occasion to notice. 

When common resin was thus treated, I obtamed about 43 
per cent, of the coal, which, after being exposed to a red heat 
in a loosely covered platina crucible, still amounted to s^per 
cent, and by the slowness of its combustion and other circum^ 
stances which need not here be related, approached very 
nearly to the characters of some of the mineral coals.* 

• The difference of the quantity of carbon, which may be obtained in the state of 
coal from resinous substances by the humid and by the dry way, is very considerable; 
we may take common resin as an example, for when 100 grains were exposed to simpk 



Mr. Hatchett on an artificial tanning Substance. Aei 

The effects produced by sulphuric acid upon turpentine aind 
resin are manifestly caused by the union of the two constituent 
principles of the latter (namely, hydrogen and carbon) with 
part of the oxygen of the former, so that sulphureous acid, 
water j and coal are produced. I therefore availed myself of 
this process, by which coal could be progressively formed 
whilst the original substance was gradually decomposed, to 
make the following experiment. 

A quantity of common turpentine was treated with sulphuric 
acid in the way which has been described, and different por- 
tions of the solution b^g poured at different periods into 
water whilst the remainder was digested during several days, 
I thus obtained from the same original substance, yellow 
resin, brown resin, black resin, and coal. I then digested 
a portion of each of these, as well as some of the turpentine, in 
separate vessels with nitric acid until they were completely 
dissolved, and afterwards reduced them to dryness. The 
different residua varied in colour from yellow to dark brown, 
corresponding, to the substances which had been employed. 
These were then dissolved in distilled water, and were exa- 
mined by solution of isinglass and other reagents. 

1. The solution of the residuum of turpentine was pale 
straw colour, and did not precipitate gelatine.* 

s. That of yellow resin resembled the former in every respect. 

3. That of the brown resin was of a deeper yellow, but in 
other particulars resembled the above. 

4. That of the black resin on the contrary yielded a consi-< 
derable portion of the tanning substance, — and 

distillation in a small glass retort placed over an open charcoal fire, the residuum of 
coal only amounted to } of a grain. 



^3d Mr. Hatchett m «n artificial tanning Suktancf. 

g. Tfa^t of th^ CQ^l ^fibrdfsd it in gre»t abun({fui«e, 

Hence i^ apjpe^$, th?it these ^iff^ent modifiQadons of tUi^ 
poiitine yielded thp tanning substance only in proportion to 
tl»e qiwntity of their Qrigii^ftl farbon, which, by oxidizein«it, 
bgd hew progroissiY^ly converted into coal.^ 

Q^b^ 9ub$;t^C!e8, 'v^hsn reduced into coal in the humid way, 
w?re iq lilce mjiiiner formed into t^ tanning mfo^tance by nitric 
acid. In fact I found this to be the wnatant rosuh, and amongat 
^? iH^ny sub^taivjeft which were examiniNU I shall mention 
Vi|rjk>i|¥ kindfii of wopd, copal, amber, and wax, all of which, 
y^h^ reduced to. ooal by sulphuric add, yielded similar pio* 
ductS;, hy suhiseQuent treaH^rat with nitric acicL 

£iv^ thill sibstttice may likewise.be. ardfictally produced 
vitboiit the hielp of nitric zeid, although in a less proportion, 
afi[ w^U a^ with some slight variations in its chafacteristic proi* 
per|i^ ; for, a&I hgve already observed, when any of the resins 
Of gum refills ( such as common i^sin, derai, asa fbetida, &c. ) 
hffV9 b^en long digested with s^huric add sa as to assume 
tbe appearance and. general chanacters of coal, if afbeirwards 
tlM^ysur^ digested with alcohol, a portion, is (fissohred^ and a cfaurk 
brown solution is formed which by evaporation yielde a mass 
solvblh m water as well as in alcohol, and which precipitates 
gelatine, acetite of lead, and muriate of tin^ but produces cmly 
s^ veify slight effect on oxy sulphate of iron. This substance, 
t^r/9fore, which may thus be separated by alcohol from the 
coal formed from resinous bodies by sulphuric acid, evidently 
contains, soma of the. tanning matter, which has been produced 
during the carbonization of those substances. 

* Some late experiments have however convinced roe that carbon need not be abso- 
lutely converted into coal in order to produce the artificial tanning substance; but this 
will be more fully explained in a subsequent Paper; 



Mr.. HAficiiCtT w c^ ctrtificM trnntr^ Sudstafici. 2S3 

A ilMuiial proo^ss^ vef y sutular tcf thi&, I mUbh suspect takes 
place in some cases where peat is formed ; I say in some 
tastes^ becauis^ tke production of tanning matter does not seem 
to^ be absoltitely ar nebessary consequence attendant 6n the 
foralation of peat'; for inman^y places wiiere the'latter abounds, 
thei former cannot be detected, whilst in others, it is very 
abnndanty and acts powerfully on animal bodied which* have 
accidentally been exposed W itsf effects. 
• . There are many facts of this kir^'upon recofd, such as the 
aocount of the bddies' of the man and- woman^ preserved m 
ifte- moors near the woodlands- in Derbyshire, said alsaof the 
woman found in the ntorass at Axholm, in LanOolhShffe,* 
Now I^aiti moch iriclined to believe, that the tanning, substance 
wivch'so much abounds in tbese ancT some other peat moors, 
did not originally exist in the vegetable sttbstancesl from' which 
tile: pteat has been produced, but tbat it hks h€en and continues 
to be progressively formed ( under certiain favourable drcmD* 
stances ) during the gradual carbonizalidn and cbaMer&ioii of 
the; vegetable matter intd peat. 

Iirmost of the former pilpers which I hav^ had iJie hbiiour 
to lay befbre the Royal Society, I haverfor greater pfeirspicnity 
generally concluded- with a^ recarpitidatron of the contents, but 
inthe ptesent case, this uf^peats tb be sitperfluouii, as the whole 
may be ODncentrated inta one simpie^fkct;. namely, thairasub* 
stanee viery analogous to tiannin, whrds-has^hidierto been con^ 
sidered asone of the proximabe principled'of vegetables^ may 
at any time be produced, by expo^g carfoonaceoixs sUbstaiiees, 

• PhU. Tnuis. Vd, XXXVIII. p, 413. Ibid. Vol. XLlV. p. 571* 



224 ^^' Hatchett an an artificial tanning Substance. 

whether vegetable, animal, or mineral, to the action of nitric 
acid. 

Since the preceding experiments were made, I have farther 
proved the efficacy of this substance* by actual practice, and 
have converted skin into leather by means of materials which, 
to professional men, must appear extraordinary, such as, deal 
saw-dust, asphaltum, common turpentine, pit-coal, wax candle, 
and a piece of the same sort of skin. 

Allowing, therefore, that the production of this substance 
must for the present be principally* regarded only as a curious 
chemical fact not altogether unimportant, yet as the principle 
on which it is founded appears to be developed, we may hope^ 
that a more economical process will be discovered, so that 
every tanner may be enabled to prepare his leather even from 
the refuse of his present materials. 

The organized bodies and their products have only of late 
years much attracted the attention of chemists, many of whom, 
even at this time, ( although the modes of chemical examina«< 
tion have been so much improved,) seem disgusted and 
deterred by the Proteus-like changes which take place when-^ 
ever these substances are subjected to experiment. 

But these variable and endless alterations of their properties 
seem rather calculated to operate as incitements to investi- 
gation ; for by the accumulation of facts resulting from the 
changes produced in these bodies by disuniting and by re* 
combining their elementary principles, not only will chemistry 
as a science become farther illumined and extended, but it 
will, as it has hitherto done, render great and essential services 
to the arts and manufactures. 



L 



C ««*!] 



* I 



XIII- Tfe Case ofafattgmwn ff^anum in whom the Ovarid were 
deficient^ By Mr. Charles Pears, F. L. S: Cammunicated by 
the Right Han. Sir Joeepfh Banks, K. B. P. R. S. 



Read May 9, 1805, 

1 H£ following case is. laid before this learned Sodety, as an 
additieii to those ^eady registered in the Philosophical Trans- 
actions, with the view of eluddating such i^ysblogical inqi&ies 
as are connected with the state of the organs of generation, 

Ann Joseph was born at Diserth, in Radnorshire, North 
Wales, August 4, 1770. She was of a fair florid complexion, 
and blue eyes, dark-brown hair, a flat nose, and thick Kps; 
She was naturally mild, but when irritated, was sometimes 
malicious and revengefuL In. her diet she was remarkably ab- 
stemious, eating little of animal food, no fresh vegetables, and 
so small a portion of bread, that she often did not consume a 
j^enny loaf in the course of a week. If at any time she was 
prevailed upon to take several kinds of food, her stomach was , 
so much affected by it, that she fainted away ; and if she ^ad 
eaten a hearty meal, these faintings would be repeated. 

She was of a costive habit^ seldom having a passage inr her 
bowels oftener than once in nine days, and sometimes only 
<»ice in fourteen* She slept well,.and could endure hard work, 
but was slow in performing it. Having ceased to grow at ten> 
years of age^ she was in stature not more than 4 feet 6 inches^ 

MDCCCV. G g 



8ft6 Mr. Pears on the Ca^^ f^ full grown Woman 

high. Her breadth across the shoulders was as much as 14 
inches, bu* her />^/vw, (contrary to what is usually observed in 
<b« pjFCjHirtvms of the jfejo^le ^fceieton,) meftsured only ^ 
inciyes, \6:<i«o[i the o^a ilia 9prfiS^ ^;««7yw. Her brewft$>and 
nipples never eijlitrg^^ pioiie rl^^vii w ^h^/jiwte subjeet; she 
never menstruated : there was no appearance of hair on the 
pubes, nor were there any indications of puberty either in 
mind or body, even at ^bar^y-tnine years of age ; on the con- 
trary, she always expressed aversion to young men who were 
too^fiunjliar Miiiih hen 

At the age of twenty-one she eicpressed much uneasmess at 
findh^ hera^ Afferent >f]7om other young women » which she 
attrijbirted to iiat having menstruated ; and was so desirous of 
xielief that she frequently took^medical advice for that purpose. 
V Fron^ her infancy also she was liable to cpmplaints in her 
€hpst, attended .withxough, that came upon her at intervals in 
^^dent attacks, and increased in violence as sihe advanced in 
life. In her twenty-^ninth year one of these attacks came cm, 
attended with convulsions^ of which she died after a few hours 
illness. 

After death, die female organs were taken out and pre^ 
served. :In this sitate they were ^hown to l^r Jos^k Banks, 
at whose request their intemal structure was accurately exa- 
mined, and the following appearances were observed, which 
are illus^ted in the annexed drawing of them, made by Mr. 
Clift. 

The psiincae and uterus had the usual form, but had never 
increased beyond the^r diae in the infant state; the passage 
mto the uterus through the <:ervK was oblique. The cavity cf 



IfiifosTnint.ltia CCC\ flatfX.p. 7jtf 




in whom the Ovaria were deficient. S27 

the uterus was of the common shape, and the Fallopian tubes 
were pervious to the fimbriae ; the coats of the uterus were 
membranous. 

The! evarik were sa indistinct as rather to show the rudiments 
which ought to have formed them, than any part of their 
natural structure. All these appearances will be better under- 
stood by their representation in the annexed drawing ( Plate 
V. ) than from any description that can be given. 

The history of this case, with the account of the dissection, 
becomes valuable, as it shows that an imperfect state of tBte 
cAraria is not only attended with an absence of all the cha- 
racters belonging to the female after pub rty, but that the 
uterus itself, although perfectly foimed, is checked in its 
growth for want of due structure of those r arts. 

That there is an intimate connection between the ovaria and 
uterus has long been ascertained ; but that the growth of the 
uterus should so entirely depend upon that of the ovaria, f 
believe to be a new fact ; at least it has not been. puBiiished ht 
any v/ork that has come under my observation. 



G g 2 



IMS 3 



XIV. A Description of Malformation in the Heart of an Infant. 
JSy Mr. Hugh Chudleigh Standert. Qmmtmicated ly Anthony 
Carlisle, Esq. F.R.S. 



Read May 9, 1805. 

_ ^ < • 

1 HE child, from whom the subject of the present description 
was taken, died at the age of ten days ; during which period 
all the animal functions seemed to have been regularly dis- 
charged, with this exception, that the skin exhibited the purple 
or blue colour^ so often noticed in cases of imperfect pulmo- 
nary circulation. 

V The body was fleshy, somewhat less than the usual size, 
and the extremities were livid. All the viscera were in a 
natural state, except the heart, which presented the following 
remarkable structure. 

On viewing it externally, only one auricle could be observed, 
into which the pulmonary veins, and venae cavae, entered in 
their ordinary directions. The pulmonary artery was wholly 
deficient ; and, on dissection, it appeared that the body of the 
heart possessed but one ventricle, separated from the auricle 
by tendinous valves, and opening into the aorta. 

The auricle was also single, having a narrow muscular band, 
which crossed the ostium venosum, in the place of the septum. 
The aorta sent off an artery, from the situation of the ductus 
arteriosus, which divided itself into two branches, supplying 
each mass of the lungs. These vessels were of small diameter. 



Mr. Standert's Description, &c. 229 

The arterial system had been injected with wax, and, in 
removing the heart from the thorax, this pulmonary branch of 
the aorta was unfortunately cut away. 

The pulmonary veins were four in number ; but neither the 
area of these veins, nor that of the vessel which acted as the 
pulmonary artery, exceeded half the common dimensions. 
•• This child, when alive, came under the observation of Dr. 
Combe, who did not perceive that its respiration, temperature, 
or muscular action, were materially affected. In the records 
of malformation of the heart, the present case is extraordinary, 
resembling in organization the amphibious animals, rather than 
the mammalia. That an infant should have existed so long, 
under such circumstances, carrying on all the vital functions, 
appears a physiological fact of some importance, especially as 
the dependence of life on respiration, and the changes pro- 
duced in the vascular system, are so imperfectly understood. 

EXPLANATION OF THE DRAWING. (Plate VI.) 

Fig. 1 . A view of the left side of the heart, the common 
ventricle being opened by a simple incision, showing the valves 
of the ostium. 

a, The aorta. 

b, The common trunk of the two branches of the right pul- 
monary veins. 

c, The vena cava superior. 

d, e. The two trunks of the left pulmonary veins. 

Fig. 2. A view of the right side of the heart, exhibiting the 
common cavity of the auricle, a portion of its parietes being cut 
away, with the vena cava inferior. 



«3o Mr. Stanbert's Description , &c. 

a, c, The two ti'unks of the left pulmonary vein, 

b, The vena cava superior. 

d, The aorta. 

e, The trunk of the right pulmonary veins. 
/, The muscular band in the auricle. 

These drawings are of the natural size, and the subject of 
them is preserved in the collection of Dr. Combe. 



J^i/p^.Tn//i.'\MDC C CT.J'/iifeVIp.i3c 




C «si 3 



V. Ona MeAod tfmalyxing Stones (^oMginmg fixed Alkali^ fy 
Means of the Boracic Acid. By Humphry Davy, Esq. F. R. S. 
Professor of Chemistry in the Royal Institution. 



Read May 16, 1805. 

I HAVE found the boradc acid a very useful sujbtstaape for 
bringing the constituent parts of stones ccmtainiag a fixed alkali 
into solution* 

Its attraction for the different simple earths is co^$ideraUe 
at the heat of ignitipn, hut the compounds that it iorjfis with 
them are easily decomposed by the mineral acids dissolved in 
v^atear, and it i« (Hi thi$ circuj^kstance Jtljiat the me^tho^ qf analysis 
is founded. 

The processes are very simply. 

100 grains of the stone to he exmnined in very fine powder, 
must be fused for about hjdf .an .h(^r,;iit a s^rops^g ^§^ heajt, in 
a crucible of plsitina w «ilv/er, with %<f9 gr^inp ctf tigya^ afii^- 

An ounce and half of nitric acid, diluted with sey^ ,or ,eig^t 
times its quantity of water, must be digested upon the fused 
mass till the whole is decomposed. 

The fluid must be evaporated till its quantity is reduced to 
an ounce and half or two ounces. 

If the stone contain silex, this earth will be separated in the 
process of solution and evaporation ; and it must hz collected 
upon a filter, and washed with distilled water till the boracic 
acid and all the saline matter is separated from it. 



2$2 Mr. Davy on a Method of analysing Stones^ 8cc. 

The fluid, mixed with the water that has passed through the 
filter, must be evaporated, till it is reduced to a 'convenient 
quantity, such as that of half a pint ; when it must be saturated 
with carbonate of ammonia, and boiled with an excess of this 
salt, till all the materials that it contains, capable of being pre- 
cipitated, have fallen to the bottom of the vessel. 

The solution must then be separated by the filter, and the 
earths and metallic oxides retained. 

It must be mixed with nitric acid till it tastes strongly sour, 
and evaporated till the boracic acid appears free. 

The fluid must be passed through the filter, and subjected 
to evaporation till it becomes dry ; when, by exposure to a 
heat equal to 450* Fahrenheit, the nitrate of ammonia will be 
decomposed, and the nitrate of potash or soda will remain in 
the vessel. 

It will be unnecessary for me to describe minutely the 
method of obtaining the remaining earths and metallic oxides 
free frcm each other, as I have used the common processes*. 
I hav^ separated the alumine by solution of potash^ the lime by 
sulphuric acid, the oxide of iron by succinate of ammonia, the 
li^ganese by hydrosulphuret of potash^ and the magnesia by 
pure soda. 



C «33 3 



XVL On the Dtrectian and Velocity of the Motion of the Sun, and 
Solar System. By William Herschel, LL. D. F. R. S. 



Read May 16, 1805. 

Our attention has lately been directed again to the construc- 
tion of the heavens, on which I have already delivered several 
detached papers. The changes which have taken place in the 
relative position of double stars, have ascertained motions in 
many of them, which are probably of the same nature with 
those that have hitherto been called proper motions. It is well 
known that many of the principal stars have been found to 
have changed their situation, and we have lately had a most 
valuable acqidsition in Dr. Maskelyne's Table of proper 
motions of six and thirty of them. If this Table affords us a 
proof of the motion of the stars of the first brightness, such as 
are probably in our immediate neighbourhood, the changes of 
the position of minute double stars that I have ascertained, many 
of which can only be seen by the best telescopes, likewise 
prove that motions are equally carried on in the remotest parts 
of space which hitherto we have been able to penetrate. 

The proper motions of the stars have long engaged the 
attention of astronomers, and in the year 1783, 1 deduced from 
them, with a high degree of probability, a motion of the sun 
and solar system towards x Herculis. The reasons which 
were then pointed out for introducing a solar motion, will now 
be much strengthened by additional considerations; and the 

MDCCCV. H h 



834i ^' Herschel on thf Direction of the 

above mentioned Table of well ascertained proper motions will 
also enable us to enter rigorously into the necessary calcula- 
tions for ascertaining its direction, and discovering its velocity. 
When these points are established, we ^hall be prepared to 
draw some consequences from them that will account for many 
phenomena which otherwise cannot be explained. 

The scope of this Pap^r, wherein it is intended to assign 
not only the direction, but also the velocity of the solar motion, 
embraces an extensive field of observation ai>d calculation ; 
but as to give the whole of it would exceed the compass of the 
present sheets, I shall reserve the velocity of the solar motion 
for an early future opportunity, and proceed now to a disqui- 
sition of the first part of ipy subject, which is the direction of 
the motion of the sun and solar system. 

Reasons for admitting a solar Motion. 

It may appear singular that, after having already long ago 
pointed out a solar, motion, and even fixed upon a star towards 
which I supposed it to be directed, I should again think it ne- 
cessary to show that we have many substantial reasons for 
admittii^ such a motion at all. What has induced me to enter 

« 

into this inquiry is, that spme of the consequences hereafter to 
be drawn from a solar motion when established, seem to con- 
dradict the very intention for which it is to be introduced. The 
chief obi ect in view, when a solar rtMtion was proposed to be 
deduced from observations of the proper motionis of stars, was 
to take away many of these motions by investing the sun with 
a contrary one. But the solar motion, when its existence has 
been proved, will reveal so many concealed real motions, that 
we shall have a greater sum of them than it would be necessary 



t 

Motion of the Sun, and solar System. 235 

to admit, if the sun were at rest ; and, to remove this objection, 
the necessity for admitting its motion ought to be well 

established. 

Theoretical Considerations. 

* . - ' * 

A view of the motion of the moons, or secondary planets, 

round their primary ones, and of these again round the sun, 

may suggest the idea of an additional motion of the latter 

round some other unknown center; and those who like to 

• • • . • - , 

indulge in fanciful reviews of the heavens, might easily 
build a system upon hypotheses not altpgether without some 
plausibility in their favour. Accordingly we find that Mr. 
Lambert, in a work which is full of the most fantastic imagi- 
nations, has framed a system wherein the sun is supposed to 
move about the nebula in Orion.* But, setting aside the extra- 
vagant idea of making this luminous spot a center of motion, 

■ * • - 

it must certainly be admitted that the solar motion itself is at 
least a very possible event. 

I have already mentioned, in a note to my former Paper ,-[• 
that the possibility of a solar motion has also been shown from 
theoretical principles by the late Dr. Wilson of Glasgow ; and 
its probability afterwards, from reasons of the same nature, by 
Mr. De la Lande. The rotatory motion of the sun, from 
which he concludes a displacing of the solar center, must cer- 
tainly be allowed to indicate a motion of translation in space ; 
for though it may be possible, it does not appear probable, that 
any mechanical impression should have given the former, 
without occasioning the latter. But, as we are intirely unac- 
quainted with the cause of the rotatory motion, the solar 

• See SysUme iu Monde di Mr. Lambbrt, page 15X1 and 158. 
t Sec Phil, Trans, for the year 1783, page 283. 

Hh 9 



f 3® Jf^- Herschel on the Direction of the 

translation in space from theoretical reasons, can only be 
admitted as a very plausible hypothesis. 

It would be worth while for those who have fixed instru- 
ments, to strengthen this argument by observing the stars 
which are known to change their magnitudes periodically. 
For as we have great reason to ascribe these regular changes 
to a rotatory motion of the stars,* a real motion in space may 
be expected to attend it ; and the number of these stars is so 
considerable- that their concurring testimony would be very 
desirable. 

Perhaps Algol, which according to these ideas must have a 
very quick rotatory motion, may be found to have also a con^ 
siderable progressive one ; and if that should be ascertained, 
the position of the axis of the rotation of this star will be in a 
great measure thereby discovered. 

An argument from the real motion to a rotatory one ia 
nearly of equal validity, and therefore all the stars that have a 
motion in space may be surmised to have also a rotation on 
their axes. 

Symptoms of parallactic Motions. 

But, setting aside theoretical arguments, I shallnow proceed 
to such as may be drawn from observation ; and, as all pjsiral- 
lactic motions are evident indications that the observer of them 
is not at rest, it will be necessary to explain three sorts of 
motions, of which the parallactic is one ; they will often engage 
our attention in the following discussion* 

Let the sun be supposed to move towards a certain part of 
tl^e heavens, and since the whole solar system will have the 

« 

^ See Phil. Tram, for the year 1795, pa2;c 6Si. 



Motion of the Sufty and solar System. 237 

Mme motion, the stars must appear to an inhabitant of the 
earth to move in an opposite direction. In the triangle sp a^ 
Plate VII. Fig. 1, let s p represent the parallactic motion of a 
star ; then, if this star is one that has no real motion, sp will 
also be its apparent motion ; but if the star in the same time, 
that by its parallactic motion it would have gone from s to p^ 
should have a real motion which would have carried it from s 
to r, then will it be seen to move along the diagonal s ay of 
the parallelogram srpa; and p a, which is parallel and equal 
to sVy will represent its real motion. Therefore, in the above 
mentioned triangle sp j, which I suppose to be formed in the 
concave part of the heavens by three arches of great circles, 
the eye of the observer being in the center, the three sides will 
represent, or stand for, the three motions I have named : sp the 
parallactic, /> a the real, and sa the apparent motion of the star: 
The situation and length of these arches, in seconds of a degree, 
will express, or rather represent, not only the direction but 
also the quantity of each motion, such as it must appear to an* 
eye in the above mentioned central situation. And calling the 
solar motion S, the distance of the star from the sun rf, and 
the sine of the star's distance from the point towards wliich the 
sun is moving (p, the parallactic motion, when these are given, 

A S' 

will be had by the expression ^-^- = sp. This theorem, and its 
corollaries, of which frequent use will be made hereafter, it 
will not be necessary here to demonstrate. 

When I call the arch pa the real motion, it should be under- 
stood that I only mean its representative ; for it must be evi- 
dent that the absolute motion of a star in space, as well as its 
intrinsic velocity, will still remain unknown, because the incli- 
nation of that motion on which also its real velocity will: 



238 Dr. Herschel on the Direction of the 

depend, admits of the greatest variety of directions. We are 
only acquainted with the plane in which the tnotion must be 
performed, and with the length of the arch in seconds by 
which that motion may be measured. We riiay add that the 
chords of the arches representing the three motions are the 
smallest velocities of tfiese nntotions that can be admitted ; for 
in every other direction but at ri^ht angles to the line of sight, 
the actual space over which the star will m6ve must be greater 
than the arch or chorti by which its motion is represented. 

Now, since a motion of the sun will occasion parallactic 
motions of the stars, it follows that these again must indicate 
a solar motion ; but in order to ascertain whether parallactic 
motions exist, we ought to examine those stars which are most 
liable to be visibly affected by solar motion. This requisite 
points out the brightest stars as the most proper for our pur- 
pose ; for any star may have a great real motion, but in order 
to have a great parallactic one, it must be in the neighbourhood 
of the sun. And as we can only judge of the cfistance of the 
stars by their splendour we ought to choose the brightest, on 
account of a probability that, being nearer than faint ones, they 
may be more within the reach of parallax, and thus better 
qualified to show its effects. 

We are also to look out for a criterion whereby pat*allactic 
may be distinguished from real motions ; and this we find in 
their directions. For if a solar motion exists, all parallactic 
motions will tend to a point in opposition to the direction of 
that motion ; whereas real moti(His will be dispersed indiscri* 
minately to all part^ of space. 

With these distinctions in view, we may examine the proper 
motions of the principal stars ; for these, if the sim is not at 



Motion, qf tlm Sun^ and solar System. 339 

rest, musj either bfe intirtely parallactic, on at least composed of 
real and parallactic motions ; in the latter case they will fall 
under, the cjenomination ofv one of the three motions we have 
defined, namely sa^ the apparent motion of the star. 

In consequence of this principle I have delineated the meeting 
of the archesi arising, from a calculation of the proper motions 
of the 36 stars in Dr. Maskelyne's catalogue, on a celestial 
globe ; and, as all great circles of a sphere intersect each other 
in two opposite points, it will be necessary to distinguish them 
both : for, if the sun moves to one of them, it may be called 
the apex of its motion, and as the stars .will then have a paral- 
lactic motion to the opposite one, the appellation of a parallactic 
center may very properly" be given to it. The latter falling 
into the southern hemisphere, among constellations not visible 
to us, I shall only mention their opposite int^sections ; and of 
these I find no legs than ten that are made bty qtars of the first 
magnitude, in a very limited part of the heavens, about the 
constellation of Hercules. Upon all the remaining, surface of 
the same globe there is not the least appearance of any other 
than a promiscuous situation of. intersections ; and^iof these 
only a singie on^e is madei by arche9:Pf principal starSj 

The ten intersectii>g points, made. by the. brightest stars ace 
as follows. The 1st is by Sinus and Arpturus^.in the mouth of 
the Dragon. The, ad by Skius and^Capella^ near the following 
hand of Hercules.. The 3<J bySicius and Lyra,, between the 
hand and knee of .Hercul^e?. The 4th J>y Sirlus and Aldebaran, 
in the following leg , of Hercules. The 5th by Arcturus and 
Capella, north of the preceding wing of the Swan.. The 6th 
by Arcturus and, Aldebaran. in: the neck of the Dragon, The 
7th by Ai^cturus and Procyon, in the preceding foot of Hercules. 



«4,o 



Dr. Herschel on the Direction of the 



The 8th by Capella and Procyon, south of the following hand 
of Hercules. The 9th by Lyra and Procyon, preceding the 
following shoulder of Hercules. And the loth is made by 
Aldebaran and Procyon, in the breast of Hercules. 

The following Table gives the calculated situation of these 
ten intersections in right ascension and north polar distancei 

Table L 



No. 
1 


Righl 


t Ascension. 


Polar Distance. 


^55" 


39' 50" 


36- 


41' 34" 


S 


«75 


9 3« 


64 


21 48 


3 


S72 


23 58 


58 


83 «4 


4 


263 


25 38 


44 


39 47 


5 


290 


58 


32 


7 83 


6 


26y 


2 19 


33 


57 «o 


7 


835 


3 13 


46 


21 34 


8 


27s 


51 49 


73 


7 56 


9 


266 


46 49 


66 


48 11 


10 1 s6o 


1 29 


60 


59 34 



We might rest satisfied with having shown that the paral- 
lactic effect of which we are in search is plainly to be per- 
ceived in the motion of the brightest stars ; however, by way 
of further confirmation, we may take ki some large stars of 
the next order, in whose motions evident marks of the in- 
fluence of parallax may likewise be perceived. When the 
intersections made by their proper motions and the arches in 
which the stars of the first magnitude are moving, are exa- 
mined, we find no less than fifteen which unite with the former 
ton, in pointing out the same part of the heavens as a paral- 
lactic center. It will be sufficient only to mention the opposite 



Motion of the Sun, and solar System. 241 

points of the situation of these intersections, and the stars by 
which they are made^ without giving a calculated table of 
them. 

The 1st is the following leg of Hercules, and is made by 
Sirius and /i Tauri. The ad is also in the following leg of 
Hercules, by Sirius and a Andromedse. The sd is in the fol- 
lowing hand of Hercules, by Sirius and a Arietis. The 4th in 
the neck of the Dragon, by Arcturus and fi Tauri. The 5th 
between the Lyre and the northern wing of the Swan, by 
Capella and x Andromedae. The 6th near the following hand of 
Hercules, by Capella and u Arietis. The 7th preceding the 
head of Hercules, by Lyra and (3 Tauri. The 8th between the 
L)rre and northern wing of the Swan, by Lyra and a Andro- 
medae. The 9th in the following arm of Hercules, by Lyra 
and » Arietis. The loth in the following leg of Hercules, by 
Aldebaran and fi Tauri. The 1 ith in the following leg of 
Hercules, by Aldebaran and a Andromedae. The 12th in the 
head of Hercules, by Aldebaran and ec Arietis. The isth in 
the following arm of Hercules, by Procyon and (i Tauri. The 
14th in the back of Hercules, by Procyon and a. Andromedae. 
And the 1 5th near the following arm of Hercules, is made by 
Procyon and a Arietis. 

An argument like this, founded upon the most authentic 
observations, and supported by the strictest calculations, can 
hardly fail of being convincing. And though only the ten 
principal apices of the twenty-five that are given have been 
calculated, the other fifteen may nevertheless be depended 
upon as true to less than one degree of the sphere. 



MDCCCV. I i 



94* Dr. HsRCSHFi- m th Direction (^ihe 

Changes in the Position of double Stars. 

We have lately seen that the alterations in the relatiTf 
situation of 9 great number of double ^tairs mi^y jt^ apcoimted 
for by a parallactic ^lQtion. Among the s^ st;atrs which I have 
given, the changes of more thap half of them ^pp#ar to he qf 
this nature ; and it will certainly be more eligible to aiscribp 
tliem to the effect of parallax than to. admit; po ra^y separate 
motions in the different stars ; especially whisn it is cqasidexj^cl 
that if the alterations of the angle of positioix were owjing <;o fi 
motion of the largest star of each %ety the cttjreiciion of *uch 
motions must, in contradiction to all probability^ tend nearly tp 
one particular part of the heavens. •[ 

This argument, drawn from the ch^Bg^ of thq position qf 
double stars, may be considered as deriving its validity from 
the same source with the former, namely, the parallactic 
motions of at least 38 more stars, pointing out the same apejc 
of a solar motion by their direction to its opposite parallactic 

center. 

Incongruity of proper Motions. 

It m^ be remarked that the proper motions of the stars, \i 
they were in reality such as they appear to be, ^yould contiHti 
a certain incongruous mixture of great velocity and extreme 
slowness. Arcturus alone describes annually an arch of more 
than two seconds : Aldebaran hardly one-tenth and a quarte;r 
of a< second : Rigel little more than one-tepth aiid a h^lf : §ven 
Lyra moves barely three and a quarter tenths of a sQpond,^ 
while Procyon has almost four times that velocity. Out of 3^ 
stars whose proper motion we have examined, there are 15 
that do not reach two-tenths of a second : jQ Virginis moves 



MMhfn 4^ Ute ^n\ and sqUp System. 943 

s^ent^--«hren hiMdrecMis^ «k) a. Cyg^i^ cfrily t&x. But k wi(lf 
be shown, when the direction and velocity of the solaif motion 
come to be explained, that these kind of incongruities are mere 
parallac^ afypea^attiee:^ ; iftd thkt there is^ so» gefteral a? con- 
sistency^ among the i*eaJ motions of the st^^, that Aretums \b 
in no res^et singled- etal as^ a staa» wKose motion is- far beyond 
the res#. 

By giving this remark a pfece amofig d^e reasons^ for admit- 
tkig a * solar motion, it is not intended to Fay any particular 
stress upow it; for it may be objected that our idea' of the 
congruence or harmony of the eetes^al motions twct be no^ 
crfterion of their tfeaf fitness- and- symmetry. But when such 
discordant^ proper motions as- those f ha!Ve mentioned in stars 
of no very different lustre are under consideration, and may 
be easily shown to be only parslHaetic phertomena, the method 
by which thiy carr be done must certainly appear eligible, and 
when^ added to- many other inducements^ will throw somF 
share of weight into- the* scale. 

Siderenl Occultation of a smalt Stan. 

Of nearly the sttme-lmportaiice with the former argument is 
the aeeount of the occultation of a small star by a large one, 
wWch- F have giTen* m ray last Phper. When the solar motion 
has been established*, we shall prove that the vanishing of the 
small star near J^^Cygni, as far as we can judge at present, is 
only a parallactic disappearance. It must be granted that a reaf 
nfotion of the^ large star would also explain the same pheno- 
menon ; bmt then again, this star must be supposed to move to- 
wardi tJw very same parallaetic center which the changes in the 

lis 



244 -D^- Herschel w the Directim of the 

position of other double stars point out, and this cannot be 

probable. 

Direction of the solar Motion. 

From what ha<s been said, I believe the expe;(£ence of ad- 
mitting a solar moticm \^11 not be called in question ; oiu* next 

« 

endeavour therefore must be to investig^ its direction. 

To return to the before mentioned intersections of the arches, 
in which the proper motions of the stars are performed, I shall 
begin by proving that when the proper ; motions of two stars 
are given, an apex may be found, to which^ if the sun be sup- 
posed to move with a certain velocity, the two given moticms 
may then be resolved into apparent changes, arising from, 
sidereal parallax, the stars remaining perfectly at rest. 

Let the stars be Arcturus and Sirius, and their annual proper , 
motions as given in the Astronomer Royal's Tables. 

When the annual proper motion of Arcturus, which is. 
— 1",26 in right ascension, and -|-i",7s in north polar distance, 
is reduced by a composition of mtotions to a single one, it will 
be in a direction which makes an angle of 5^ 29' 42" south- 
preceding with the parallel of Arcturus, and of a velodty so as 
to describe annually »'',o87i8 of a great circle. 

The annual proper motion of Sirius, — o",42 in right ascen- 
sion, and -(- ^"»<^4 ^ north polar distance, by the same method 
of composition, becomes a motion of i'',ii528, in a direction 
which makes an angle of 68* 49' 41" south-preceding with the 
parallel of Sirius. 

By calculation, the arches in which these two stars move, 
when continued, will meet in what I have, called thdr parallactic 
center, whose right ascension is 75'' 39' 50'', and south polar 



^ 



Motion of the Sun^ and solar System. t^ 

is 8®* 41' 34''. The opposite of this, or right ascension 
^5^ 39' 5^" J ^"^d north polar distance 36* 41' 34'', is what we 
are to assume for the require4 apex of the solar motion. 

When a star i? situated at a certain distance from the sun, 
which we shall call 1 ; and 90"" from the apex of the solar 
motion, its parallactic motion will be a maximum. Let us now 
suppose the velocity of the sun to be such that its motion, to a 
person situated on this star, would appear to describe annually 
an arch of »'',84825, or, which is the same thing, that the 
star would appear to us, from the effect of parallax, to move 
over the above mentioned arch in the same time. 

To apply this to Arcturus, we find by calculation that its 
distance from the apex of the solar motion is 47* 7' 6" ; its 
parallactic motion therefore, which is as the sine of that dis- 
tance, will be £",08718; and this, as has been shown, is the 
apparent motion which observation has established as the proper 
motion of Arcturus. 

In the next place, if we admit Sirius to be a very large star 
situated at the distance 1 ,6809 ^^^^^ ^^^ ^^^ compute its elon- 
gation from the apex of the solar motion, we shall find it 
138** 50' 14'',5. With these two data we calculate that its pa- 

(b s 

rallactic motion will be y-j = sp=z i",ii528 ; and this also 
agrees with the apparent motion which has been ascertained 
by observation as the proper motion of Sirius. 

Now since, according to the rules of philosophising, we 
ought not to admit more motions than will account for the 
observed changes in the situation of the stars, it would be 
wrong to have recourse to the motions of Arcturus and Sirius, 
when that of the sun alone will account for them both ; and 
this consideration would be a sufficient inducement for us to 



94^ Dr. Herschel on the D^ection 6f the 

ftx ait once on the calculated afpex^ as well as on the relative 
^stances that have been assigned to these stars, if otiwr proper 
motions could with equal i^cility be resoWed into mniiar pasraln 
kctic appearances. But from the natuire of proper motions, it 
follows, that when a third star doea not lead uS' to the same 
apex as the other two, its apparent motion cannot be resoivedi 
by the ei¥ect of parallax alone. And to enhance our difficulties^ 
the number of apices, that wouM be required to solve all proper 
inotion«^ into par^Iactic ones, increases not as the number oi 
stars admitted to have proper motions, but> when their situar* 
tion happens to be favourable, a& the sum of an arithmetical 
series of natu^ral numbers, beginning at o, continued to as many 
terms as there are stars admitted : so that if two stars ^e 
only one apex, one star added to it will give three apices*; and 
t^n, for instance, will give no less than 45, aaid so on. 

The method of reasoning which, on this subject,^ I have 
adopted, is so closely connected with astronomical observations^ 
that I shall keep them constantly in view ; and therefore shall 
illustrate what has been advanced, by taking in Capella as^ a- 
third star. The three apices which then are pointed out wilt 
be that in the mouth of the Dragon, by Arcturus airid Sirim j 
a second under the northern wing of Cygnus:, by Arcturus andi 
Capella ; and a third in the following hand of Hercules^ by- 
Sirius and Capella. The calculation of them is in Table I, 

The annual proper motions of our third star in Dr. Maske- 
lyne's Tables are -f o",2i in right ascension,, and +o'',44 in 
north polar distance ; and by calculation these quantities give 
an annual motion of o'',46374« to Capella, in a directicm which 
makes an angle of 71** 35' 22'',4^ south*following with the 
parallel of this star. 



L 



Motion of the Sua, and solar System. 247 

The distanoe of Capella from the same calculated apex of 
the solar motion, by which we have already explained the 
apparent motions of the other two stars, is 80* 54/ 46''; and, 
admitting again the velocity of the sun towards the same point 
as stated before, it will occasion a parallactic motion of Capella, 
in a'direction 89'' 54' 48" south-following its parallel, amount- 
ing to s'',8 1 25. in this calculation Capella has been taken for 
a star of the first magnitude, supposing its distance from us to 
be equal to that of Arcturus. 

By constructing then a triangle, the three sides of which will 
represent the three motions which every star must have that 
is not at rest in space ; we have cxie of the sides, representing 
the apparent motion of the star, equal to o'',4637 ; the other 
side, being die parallactic motion of the star •^",8125 J ^^^ the 
included angle iS"* 19' 27''. From these data we obtain the 
third side, representing the real motion of the star, which will 
be 2^,3757 . By the given situation of this triangle v^th respect 
to the parallel of declination of Capella, the angle of the real 
motion will also be had, which rs 86"* 34' 11'' north-following 
the parallel of this star. A composition of the parallactic and 
the real motion in the directions we have assigned, will prodpce 
the annual apparent motion which has been established by 
observation. 

But to apply what has been said to our present purpose, it 
may be observed, that although we have accounted for the 
proper motion of our third star by retaining the same apex of 
the solar motion, which has given us an explanation of the 
apparent motions of the other two, yet in doing] this we have 
been obKged to assign a great degree of real motion to Capejla ; 
and to this it may be objected, that we can have ho authority 




S4j8 Dr. HbRschel on the Direction of the 

to deprive Arcturus and Sinus of real motions^ in order to give 
one of the same nature to our third star : and indeed to every 
star that has a proper motion which does not tend to the same 
parallactic center as the motions of Arcturus and Sirius. 

This objection is perfectly well founded, and I have given 
the above calculation on purpose to show that, when we are in 
search of an apex for the solar motion, it ought to be so fixed 
upon as to be equally favourable to every star which is jwoper 
for directing our choice. Hence a problem will arise, in our 
present case, how to find a point whose situation among three 
given apices shall be so that, if the sun's motion be directed 

« 

towards it, there may be taken away the greatest quantity of 
proper motion possible from the given three stars. The intri* 
cacy of the problem is greater than at first it may appear, 
because by a change of the distance of the apex from any one 
of the stars, its parallactic motion, which is as the sine of that 
distance, will be afiected ; so that it is not the mere alteration 
of the angle of direction, which is concerned. However, it 
will not be necessary to enter into a solution of the problem ; 
for it must be very evident that a much more complex one 
would immediately succeed it, since three stars would cer- 
tainly not be sufficient to direct us in our present endeavour to 
find the best situation of an apex for the solar motion ; I shall 
therefore now leave these stars, and the apices pointed out 
by them, in order to proceed to a more general view of the 
subject. 

We have already seen that the brightest stars are most 
proper for showing the effect of parallax, and that in our 
search after the (Erection of the solar motion, our aim must be 
to reduce the proper motions of the stars to their lowest* 



Motion of the Sun, and solar System. 



849 



quantities. The six prineipal stars» whose intersecting arches 
have been given, when their proper motions in right ascension 
and polar distance are brought into one direction, will have the 
apparent motions contained in the following Table, 

Table IL 



Names of the 
Stars. 



Sirius 

Arcturus - 
Capella - 
Lyra - - 
Aldebaran 
Procyon - 



Direction of the apparent 
Motions. 



68*" 49' 4o'',7 south-preceding 

55 ^9 4fiy^ south-preceding 
71 35 22,4 south-following 

56 20 57,3 north-following 
76 «9 37,3 south-following 
50 2 94,5 south-preceding 

} Sum of the apparent motions 



Quantities of the apparent 
Motions. 



1", 11528 per year 
2,08718 ■ 

0,4^374 

0,32435 

0,12341 — 

1,23941 



.// 



5",35337 



We must now recur to what has been said, when the con« 
struction of the triangle expressing the three motions of a star, 
that is not at rest, was explained ; and, as we are to find out a 
solar moti(»i which will require the least real motion in our 
six stars, an attention to this triangle will be of considerable 
use ; for when the line pa. Fig. 1, which represents the real 
motion, is brought into the situation ma, where it is perpendi- 
cular to sp, the real motion which is required will then be a 
minimum. It also follows, from the construction of the same 
triangle, that if by the choice of an apex for the solar motion 
we can lessen the angle made at s by the lines sp and sa, we 
shall lessen the quantity of real motion required to bring the 
star from the parallactic line spm to the observed position a. 

It has already been shown, in the case of Sirius and Arcturus, 

MDCCCV. K k 



«50 Dr* Herschel on the Directum of the 

that when two stars only are given, the line sp may be made 
to coincide with the lines sa, of both the stars, whereby their 
real motbns will be reduced to nothing. It has also been 
proved, by adding Capella to the former two, that when three 
stars are concerned, some real motion must be admitted in one 
of them. Now, since all parallactic motions are directed to the 
same center, a single line may represent the . direction of the 
effect of the parallax, not only of these three stars but of 
every star in the heavens. According to this theory; tenhe 
line 5 P or 5 S, in Fig. 2 , stand for the directbn of the paraU 
lactic motion of the stars ; and as in the foregoing Table we 
have tlie angles of the apparent motion of six stars with the 
parallel of each star, we must now also compute the direction 
of the line ^P oriS with the parallels of the same stars. This 
may be done as soon as an apex for the solar motion is fixed 
upon. The difference between these angles and the former 
will give the several parallactic angles Psa or Ssa^ required 
for an investigation of the least quantity ma, belonging to 
every star. 

For instance, let the point towards which we may suppose 
the sun to move, be x Herculis ; and calculating the required 
angles of the direction in which the effect of parallax^ will be 
exerted, with the six stars we have selected for the purpose of 
our investigation, we find them as in the following Table. 



-Motion ofiihe Sun, mi solar Systenti 



ft5t 



Table IH. 
Angles (f the parallactic Motion tuith the Parallel. 



Srius - - - 


3«' 


54' 


8",5 south-preceding. 


Arcturus - - - 


17 


23 


45,7 south-preceding. 


Capella 


85 


10 


3,9 south-following. 


Lyra - - - - 


35 


59 


49,5 north-following. 


Aldebaran 


71 


21 


354 south-following. 


Procyon 


47 


43 


44,6 south-preceding. 



The difference between these parallactic, and the former 
apparent angles, with the parallel of each star, will give the 
required angles for our aeccmd figure. They will be as follows. 



Table IV. 
jpparent with th 



Sinus 

Arcturus 

Capella 

Lyra - 

Aldebaran 

Procyon 



35' 

13 
20 

5 

2 



5^ 32",« south-following. 
5 5^j3 south-following. 
41 ,5 south-following. 

7.8 north-preceding. 

1.9 south-preceding. 
S9j9 south-following. 



34 

SI 

8 
18 



By these angles, with the assistance of the lines sa^ whose 
lengths represent the annual quantity of the apparent motions 
as given in our former Table, the Figure No. s has been con^ 
structed. When the situation of these angles is regulated as in 
that figure, we may draw the several lines ma perpendicular to 
SP, and, by computation, their value and sum will be obtained 
as follows. 

Kk2 



959 P^' IIerscbel Off thelXneetioH oftht 



Table V. 
Qjtantities and Sum of the least real Motions, 



Sirius 


0,65437 


Arcturus 


• 1,28784, 


Capella 


0,10887 


Lyra 


0,11281 


Aldebaran 


0,01104 


Procyon 


0,04998 




Sum 2'',2249i. 



The result of this investigation is, that by admitting a motion 
of the sun towards x Herculis, the annual proper motions of 
our six stars, oi which the sum is 5^,3537, may be reduced to 
real motions of no more than 2'^2S49. 

When first I proposed x Herculis as an apex for the solar 
motion, it may be remembered that a reference to future ob- 
servations was made for obtaining greater accuracy.* Such 
observations we have now before us, in the valuable Tables 
from which I have taken the proper motions of the six stars ; 
and I shall prove that, with their assistance, we may fix on a 
solar motion that will be considerably more favourable. 

We have already shown, that to ascertain the precise place 
of the best apex is attended with some difficulty ; but from 
the inspection of the figure which represents the quantities of 
real motion required when x Herculis is fixed upon, it will be 
seen that, by a regular method of approximation, we may 
turn the line SP into a situation where all the angles of the 

• Sec Phil. Trans, for 1783, p, 273^ line 8 % and page 274, line 4. 



Motion of the Sun y and solar System. 



»55 



apparent motion of the six stars, will be much reduced. The 
quantitieii which are required for constructing another figure 
tx> repres«it the threefold moticms of our six stars?, when a 
different apex is fixed upon, are to be found by the same 
method we have pursued in the instance of x Herculis ; and 
the figure that has been given with respect to that star, shows 
evidently that the parallactic line SP should, be turned more 
towards the line ia, representing the apparent motion of Sirius. 
We shall accordingly tiry a point near the following knee of 
Hercules, whose right ascension is 270° 15', and north polar 
distance 54° 45'. 

The result of a calculation of the angles and the least quan- 
tities of real moti<m of our six stars, according to this apex, is 
collected in the following Table^ an4 represented in Fig. 3. 



Table VL 



Start. 


Angles of the parallictic Motion 
with the Parallel. 


Anglea of the apparent with the 
parallactic Motion. 


I^east Quanti- 
ties of the- 
real Motion. 


Sirius - 
Arcturus 
Capella - 
Lyra - 
Aldebaran 
• Procyoa - 

• 


c 1 

68 51 5 south-preceding 
29 30 32 south- preceding 
y/ 54 south-following 
27 38 47 north-following 
66 20 17 south-following 
64 48 <7 south-following 


I 2^5 south preceding 
25 59 10 south -following 

6 18 38 south-following 
28 42 9 north-preceding 
10 921 south preceding 
14 46 I south-preceding 

Sum 


0,0004561 
0,9145072 
0,0509727 
0,1557761 
0,0217607 
0,3159051 


i'»4593779 



By this Table it appears that the annual proper motion of 
our six stars may be reduced to l'^4594l, which is ©'',7655 less 
than the sum in the 5th Table, where the apex was x Herculis. 

In the approximation to this point it appeared, that when 
the line of the parallactic motion of Sirius is made to coincide 



454 ^' Herschel on the THrection of the 

^ith its apparent motion, we may soon obtain a certain mini^ 
mum of the other parallactic motions ; but as Sirius is not the 
star which has the greatest proper motion, it occurred to ma 
that another minimum, obtitined from the line m which Arcturu9 
appears to move would be more accurate ; for, on account of 
its great proper motion, we have reason to suppose it more 
affected than other stars, by the parallax arising from the 
motion of the sun ; and, with a view to this, I soon was led td 
a point not only in the line of the appat'ent motion of Arcturus, 
but equally favourable to Srius and Procyon, the remaining 
two stars that have the greatest motions. 

If the principle of determining the direction of the solar 
motion by th^ stars which have the greatest proper motion be 
admitted, the following apex must be extremely near the 
truth ; for, an alteration of a few minutes in right ascension or 
polar distance either way, will immediately increase the re- 
quired real motion of our stars. Its place is : right ascensicm 
S45^ 5a' 30'', and north polar distance 40'' 22'. 

The calculated motions of the same stars by this apex will 
be as in the following Table, and are delineated in Fig. 4. 

I 

TaWe VII. 



Start. 



Angles of the parallactic Motion 
with the Parallel. 



Angles or.the apparent with the 
ptrallictic Motion. 



Least Ouanti- 

ties of the 
fcal Moinin. 



Sirius - 
Arcturus 
Capella - 
Lyra - 
Aldebaran 
Procyon - 



58 24 56 south-preceding 
95 19 4$ south-preceding 
83 44 17 south-preceding 
36 28 33 south following 
89 48 35 south preceding 

59 43 10 south-preceding 



O f » 

10 2444 
003 

24 40 21 

92 49 30 

13 18 58 

9 40 46 



following 

preceding 

following 

following 

following 

preceding 



Sum 



0,20157 
0*00003 
0,19358 
0.32396 
0,02842 
0,20839 



(fthe Sm, mi ^dla^ Syttem^ egg 

.' The jJum'of the jreal motions required, with the apwc of the 
volar motion above mentioned, i& less in this Table than that 
m the former by o''^s.\^. 

^ In the^e c»l<;»l»iipi^s we have proceeded upon the principle 
of obtaining the least possible quantity of real motion, by way 
of commgat the fBQst favouraUe Situation of a dolar apex, and 
have proved that the ^um of the observed proper motions of 
the fiiK principal stars, amountiiig: to 5",S5S4» may be the result 
cTa comp(^iti<>ii' of twQ ot^er motions, and that the real inotionir 
of these stars, if they cooid be reduced to theor smallest possible 
quantities, would not exceed o'\^s59' 

But as I do not intend to assert that these real motk^ns cart 
be actually brougfac iiown to the^ low quantities that have been 
meotiQiited, it will be itecesaary to show diat the validity of the 
arguments for establishing the method I have pursued will not 
be affected by that circumstance. In the first place then, we 
should consider that although the great proper motions of 
Arcturus, Procyon, and Sirius, are strong indications of their 
being aflfected by parallax, it does not follow, nor is it probable, 
that the apparent changes of the situation of these stars should 
be intirely owing to solar motion ; on the contrary, we may 
reasonably expect that their own real motions will have a 
great share in them. Next to this, it is evident that in the case 
of parallactic motions the distance of a star from the sun is of 
material consequence ; and as this cannot be assumed at plea- 
sure, we are consequently not at liberty to make the parallactic 
motion sp in Fig. i, equal to the line sm of the same figure ; 
hence it follows, that the real motion of the star cannot be 
from m to a, as the foregoing calculations have supposed ; but 
will be from p to a. It is however very evident, that if m^ be 



S5^ Dt' Herscbel on the IXrection of the Motion of the Sun, Sec. 

a mimmum, the line pa, when sp is given, will also be a mi- 
nimum ; and if all the ma's in Fig. 4 are minima, it follows 
also that all the ^^'s, whatever they may be, wiU give the pa^s 
as small as possible: and this is the point that was to be 
established. 

Whatever therefore may be the smn of real motions inquired 
to account for the phenomena of proper motions, our foregoing 
arguments cannot be affected by the result ; for, as by observa- 
tion it is known that proper motions do exist, and since no solar 
motion can resolve them intirely into parallactic ones, we ought 
to give the preference to that direction of the motion of the 
Sim which vnll take away more real motion than any other, 
and this, as we have shown, will be done \s^en the right 
ascension of the apex is 24^ 53' 30'^ and its north polar 
distance 40'' ss'« 



• >^/v,.^. 






s 

. / 

I I 



1 1 1 A 
I ' 



. '//MC,.r/ L\\ 



/ 



/ 



a'- \m 



/ 



/ 



/ 



/ 



. /. 



/r/icf. m /r 



m 



/ 



/ 




Y/ 



, ^^rf>^r/y/>/i 



/ 



/ 



I til. 



- ift 



ffiiJos. Jhms MI)C C C"V FfotrYVip iSff, 



< ^^,-/. 



S 



m 




I Uctur/^^4in 



^ VlrAr/Ai 



. // 



//'f/CK li 






in 



a 



. '/re. 



'///rf/,i iff 



€J 



6 






/ 



C«57 3 



XVIL OntheReproductionofBuds. -SyThomaS Andrew Knight, 
Esq. F. R. S. In a Letter to the Right Hon. Sir Joseph Banks, 



Read May 25, X805. 

MY DEAR SIR, 

lliVERY tree in the ordinary course of its growth generates, in 
each season, those buds which expand in the succeeding spring ; 
and the buds thus generated, contain, in many instances, the 
whole of the leaves which appear in the following summer. 
But if these buds be destroyed during the winter or early part 
of the spring, other buds, in miany species of trees, are gene- 
rated, which in every respect p^form the office of those- which 
prfeviously existed, except that they never afford fruit or blos- 
soms. This reproduction of buds has not' escaped the notice 
of naturalists ; but it does not jappear to have been. ascertained 
by them from which, amongst the various substances of the 
tree, the buds derive their origin. 

Du Hamel conceived that reproduced buds sprang froih pre-- 
organized germs ; but the existence of such germs has not, in 
any instance, been proved, and it is well known that the roots, 
and trunk, and branches, of many species c^ trees will, under 
proper management, afford buds from every part of their 
surfaces ; and therefore, if this hypothesis be well founded, 
many millions ofi^iich germs must be annually generated in 
^ery large tree ; wot one of which in the ordinary course of 

MDCCCV. L 1 



«58 Mr. Knight on the Reproduction of Buds. 

nature will come into action : and as nature, amidst all its exu-» 
berance, does not abound in useless productions, the opinions 
of this illustrious physiologist are, in this casie, probably 

erroneous. 

» ... 

Other naturalists have supposed the buds, when reproduced, 
to spring from the plexus of vessels which constitutes the 
internal bark ; and this opinion is, I believe, much entertmned 
by modem botanists : it nevertheless appears to be unfounded, 
as the facts I shall proceed to state will evince. 

If the fruit*stalks of the sea cale (crambe maritima) be cut 
off near the ground in the spring, the medullary substance, 
within that part: of the stalk which remains attached to the 
root, decays ; and a cup is thus formed in which water collects 
in the succeeding winter/ The sides of this cup consist of a 
woody substance, which in its texture and office, and mode of 
generation, agrees perfectly with the alburnum of trees ; and 
I conceive it to be as perfect alburaumt as the white wood of 
the oak or elm : and from the interior part of this substance^ 
within the cup, I have frequently observed new buds to be 
generated in the ensuing spring. It is sufficiently obvious that 
the buds in diis case do not spring from the bark ; but it is not 
equally evident that they might not have $prung from some 
remains of the medulla. 

In the autumn of 1803, 1 discovered that the potatoe pos* 
sessed a similar power of reproducing its Imds. Some plants 
of this species had been set, rather late in the preceding spring, 
in very dry ground, where through want of moisture they 
vegetated very feebly ; and the portions of the old roots re* 
mained sound and entire till the succeeding autumn. Being 
then moistened by rain^ many small tubers were generated on 



Mr. Knight on the Reproduction of Buds. zgg 

the surfaces made by the knife in dividing the roots kito 
cuttings ; and die buds of these^ in many instance, elongated 
into runners which gave existence to other tubers, some of 
which I had the pleasure to send to you. 

I h&ve in a former Paper rem&rked^ that the potatoe consists 
of four distinct substances, the epidermis, the true skin, the 
bark, and its internal substance, Which from Its mode of fornut- 
tkm, and subsequent office, I have supjposed to be albumous : 
there is also in the young tubes a trioisparent Ime through the 
cenlir, which is probably its medulla. Thie buds and runners 
si»*ang from the substance which I conceive to be the alburnum 
of the root, and neither from the central part of it, nor from 
the surface in contact with the bark. It must, however, be 
admitted, that the internal substance of the potatoe corresponds 
more nearly with our ideas of a medullary than of an albur- 
nous substance, and therefore this, with the preceding facts, is 
adduced to prove only l^at the reproduced buds of these 
^plants are not generated by the cortical substance of the root : 
and I shall proceed to relate some experiments on the apple, 
and pear, and plumb-tree, which I conceive to prove that the 
reproduced buds of those plants do not spring .from the 
medulla. 

Having raised from seeds a very considerable number of 
plants of each of these species in i8ot, I partly disengaged 
them from the soil in the autumn, by digging round each 
plant, which was then raised about two inches above its former 
level. A part of the mould was then removed, and the plants 
were cut off about an inch below the points where the seed- 
leaves formerly grew ; and a portion of the root, about an inch 
long, vathout any bud upon it, remained exposed to the air 

LI 8 



't6o Mr. Knight on the Reproduction of Buds. 

and light. In the beginning of April, I observed many small 
elevated points on the bark of these roots, and, removing the 
^vhole of the cortical substance, I found that the elevations 
were occasioned by small protuberances on the surface .6f the 
alburnum. As the spring advanced, many minute red.points 
appeared to perforate the bark : these soon assumed the cha-- 
racter of biids, and produced shoots, in every respect similar 
to those which would have sprung from the organized buds of 
the precedkig year. Whether the buds thus reproduced derived 
any portion of their component parts from the bairk or not, I 
shall not venture to decide ; but I am much dispte^ to believe 
that, like those of the potatoe, they sprang from the alburtious 
substance solely. * . 

The space, however^ in the annual root, between thef/ntidulla 
and the bark i^ very shiall ; and therefore it may be contended 
that the buds in theise instances may have originated from the 
medulla. I therefore thought it necessary to repeat similar 
experiments on the roots and trunks of old trees, and by these 
the buds were reproduced precisely in the same manner as the 
annual roots : and therefore, conceiving myself to have proved 
in a former Memoir,^ that the substance which has been called 
the medullary process does not originate from the medulla, I must 
conclude that reproduced buds do not spring from that substance. 

I have remarked in a Paper, which you did me the honour 
to lay before the Royal Sodety in the commencement of the 
present year, that the albumous tubes at their termination 
upwards invariably join the central vessels, and that these 
vessels, which appear to derive their origin from the albumous 
tubes, convey nutriment, and probably give exisfe^Ke to new 

• Phil. Tnms^of i8oj. 



Mr. Knight (m the Heproduction of Buds. %&t 

buds and leaves. It i& also evkient, from the facility with 
which the rising sap is tranferred from one side of a womided 
tree to the other, that the albumous tubes possess lateral, as 
well as terminal, orifices : and it does not appear improbable 
that the lateral as well as the terminal orifices of the albumous 
tubes may possess the power to generate central vessels; 
which vessels evidently feed, if they do not give existence to, 
the reproduced buds and leaves^ And therefore, as the pre-r 
cedmg experiments aj^ar to prove • diat the buds neither 
spring from the medulla nor the bark, I am much inclined to 
believe that they are generated by central vessels which spring 
from the lateral orifices of tl^ alburnous tubes. The practica- 
bility of pn}pagating some plants from their leaves may seem 
to stand in opposition to this hypothesis ; but the central vessel 
is always a component part of the leaf, ' and from it the bud 
^nd young plant probably originate. j j 

I expected to discover in seeds ia similar power to regenerate 
their buds; for the cotyledons of these, though dissimilar in 
organization, execute the ofike of the alburnum, and contain a 
similar reservoir of nutiiment, and at (mce supply the place of 
the alburnum and the leaf. But no experiments, which I have 
yet been able to make, have been decisive^ owing/to the diffi- 
culty of ascertaining the number of buds previously existing 
within. the seed. Few, if any, seeds, I have reason to belie ve, 
contauii : leiss than three budst, one only of which, except in 
tuuses of accident, germinates ; and sc»ne seeds appear to con- 
tain a much greater number. The seed of the peach appears 
to be provided with ten or twelve leaves, each of which pro- 
bably Covers the rudiment of a bud, and the seeds, like the 
buds of the horse-chesnutj^ contain all the leaves and apparently 



fiiGs Mr. Knight 6nJhe Btproduction of, Bw^. 

all the buds of the sticceeding year : and I have never beeii 
kble to satisfy myself that all the buds w^re eradicated withput 
having destroyedthebase of the plumule, in which the power 
of reproducing buds .probably re^ides^ if such powdr exists. 

Nature appears to have denied to araiUal and Mennial plants 
(at least to those which have been the subjects of my experi- 
ments?) the power which it has given to perennial plants to 
reproduce their buds.; but nevertheless some biennials possess, 
under peculiar circuriistances, a very singular resource, wh^i 
all their biids have been destroyed; A turnip, bred between 
the English and Swedish variety, from which I had cut off the 
greater part of its' fruit-stalks, and of which all the buds had 
been destroyed, remained some weeks in an apparently dor^ 
mant state ; after which the first seed in sach pod germinated^ 
and bursting the seed*vessel, seemed to execute the office of a 
bud and leaves to the parent plant, during the short remaining 
term of its existence, when its preternatural foliage perished 
with it. Whether this property be possessed by other biennial 
plants in commbn with the turnip or not, I am not at present 
in possession of facts to decide, not having made predsely the 
same experiment on any other plant. 

I will take this opportunity to correct an inference that I 
have drawn in a former Paper,* which the facts ( though quite 
correctly stated ) do not, on subsequent repetitk)n of the ex* 
periment, appear to justify. I have stated, that when a per- 
pendicular shoot of the vine was inverted to a depending 
position, and a porticm of its bark between two circular incisions 
round the stem removed, much more new wood was generated 
on the lower tip of the wound become uppermost by the 

• Phil. Trans of 1803. 



Mr. Knight on the Reproduction of Buds. 5t6$ 

ft 4 

Inverted position of the branch, than on the opposite lip, which 
would not have happened had the branch continued to grow 
erect, and I have inferred that this effect was produced by sap 
which had descended by gravitation from the leaves above. 
But the branch was, as I have there stated, employed as a 
layer, and the matter which would have accumulated on the 
opposite lip of the wound had been employed in the formation 
of roots, a circumstance which at that time escaped my atten-> 
tion. The effects of gravitation on the motion of the descending 
sap, and consequent growth of plants, are, I am well satisfied, 
from a great variety of experiments, very great ; but it will 
be very difficult to discover any method by which the extent 
of its operation can be accurately ascertained. ' For the vessels 
which convey and impel ^ the true sap, or fluid from which 
the new wood appears to be generated, pass immediately from 
the kaf-stalk towards the root ; arid though the motion of this 
fluid may be impeded by gravitation, arid it be even again 
returned into the leaf, no portion of it, unless it had been ex- 
travasated, could have descended to the part from which the 
bark was taken off in the experiment I have described. I am 
not sensible that in the different Papers which I have had the 
honour to address to you, I have drawn any other inference 
which the facts, on repetition of the experiments, do not appear 
capable of supporting. 

I am, &c. 

THO^. ANDREW KNIGHT. 

£lton« 
May ii» 1805. 



i: 8^4 3 






XVni. Scmie AccMnt of two Mummies of ihe E^ Ibis, one 

of which was in a remarkably perfect State. By John Pearson!, 
Esq, F, R.S, . . , 



Read June 13, 1805, 



i. 



Tnfi ancient Egyptians were not more remarkable for their 
attainments in science, than for the extraordinary attention 
they paid to the bodies of their deceased relatives, preserving 
their remains: by arts which are now either unknown, or 
imperfftQtly recorded^ and depositmg th^m in subterranean 
structin'es, which to this day excite the curiosity and wonder 
<){ the philosophic .traveller. . The practice of embalming was 
not confined, as is well kno\vn, to the conservation of human 
bodies exclusively j it was likewise employed to protect the 
renuins of several of their sacred animals fi^om that decay and 
dissolution which usually ensues, on the exposure of animal 
substances to the action of the earth, or of the atmosphere. 
We learn from Herodotus,^ that among the different animals 
which the. Egyptians honoured with this peculfar mode of 
sepulture, were the cat, the ichneumon, the mus araneus ter- 
restris, the ibis, and the hawk ; but, whether this be a complete 
enumeration or not, it is almost impossible, at this period of 
time^ to determine. Mummies of the hawk and of the ibis 
have been often drawn out of the catacombs ; and Olivier 
asserts, that he has not only met with the bones of the mus 

• Euterpe. 



Mr. Pearson's Account of two Mummies, &c. 265 

hraneus terrestris, but also with those of several of the smaller 
species of quadrupeds, and that the bones of different animals 
are not unfrequently contained within the same wrapper.* It 
is however confidently affirmed by different writers, that the 
more modem Egyptians have frequently included a single 
bone of some quadruped within the usual quantity of cloth, 
which they have artfully taken from some decayed mummy 
in the catacombs, and then fraudulently sold this sophisticated 
production as an ancient mummy. Hence, any general con- 

« 

elusions founded on meeting with the bones of other quadru- 
peds, must be received with diffidence and suspicion. -f* 

The mummies which are taken out of the catacombs of the 
birds at Saccara, and at Thebes, are included in earthen jars, 
closed with a cover of the same material. The cloth which 
envelopes the mummy is sometimes tolerably firm and perfect ; 
but, on removing this; we commonly meet with a quantity of 
dust, resembling powdered charcoal in its appearance, inter- 
mixed with the bones, or the fra^ents of bones, belonging to 
the creature which had been contained in it. The decomposition 
is often so complete, that no traces of the animal remain ; 
but, on other occasions, the intire collection of bones, with the 
bill of the bird, have been found in a condition sufficiently 
perfect to construct a skeleton with them. In the fourth 
volume of the Annates du Musium National d'Histoire naturelle, 
M. CuviER has published an interesting memoir on the Ibis, 
with an engraving of the skeleton of that bird, which had 
been formed of the bones collected from the catacombs at 
Thebes. That able naturalist, af:er comparing the ancient 
accounts of that celebrated bird with those of the moderns, 

• Voyage en Egypie, Tome III. chap. vm. f Phil. Trans. 1794^ 

MDCCCV. M m 



s66 Mr. PsAM02('s AcfwsU ef tun Mummm 

assigns it a plac« among the species of curlew, under the 
name of Numenios Ibia. 

The aooounta of the mummy of the ibis which have been 
nitherto made public, were collected from observatioQa made 
on it in a decayed state : I presume, therefore, that a descrip- 
tion of the mummy of an ibis in a condition unusually^ perfect, 
may not be unacceptable to the curious. Among the curiositKis, 
natural and artificial, which were collected by the late Major 
Hayes,^ in the years i8ca and 1803, were two small mumnnes, 
which he took out of the catacombs at Thebes in Upper Egypt. 
They were contained in earthen jars, and were enveloped in 
cloth, similar to those which are brougltf from Saccara. At the 
request of his family, I first examined the larger of the two, 
and found the oovejing to consist of bandages of cloth, strong 
and firm> Mid about three inches iNroad. The first drcumvo^ 
lutions of the roller separated easily; but, as I proceeded, 
they adhered more firmly to each other, and were at length 
so ck>sely cemented together by a resinous-like substance, that 
I was obliged to divide the fc^s of the ck>th with a strong 
knUe. Each layer of the bandage appeared to have beai im- 
bued with some bituminous or resinous substance, in a liquid 
state, and the roller was farther secured l^ strong pieces of 
thread, so that the whole mass was rendered extremely hard 
and coherent. When I had removed the greater part of the 
covering,. I found that it had contamed a bird, which was 
thickly covered mlh the same kind of substance that had 
cemeiskted the different strips of the roller. The examination 

* This accomplished young gentleman^ who served during the late campaign in 
Egypt, died July z6, 1803, at Rosetta, aged 25 years. By hir premature death, hii 
-«ouiMry ImI aa aUe officer, and a zealous pnomoter. of tfaq intfirssta of science^ 



tfthe Egyptian Rii^ ft<S7 

was now carried an more slowly, by picking out carefully all 
the loose bituminous matter that could be removed without 
injuring the mummy ; and, after the labour of many hours, I 
succeeded in displaying the whole bird, as it had been depo- 
sited by the embalmer. The operator who had embalmed this 
bird, had previously disposed its several parts with great order 
and regularity. 

The neck was twisted, so as to place the vertex of the head 
on the body of the bird, a little to the left side o( the stermmaii. 
The curved bill, with its concave part turned upwards, de^ 
ficended between the feet, and reached to the extr^nity of the 
tail. Each foot, with its four daws turned forwards, was bent 
upwards, and placed on each side of the head. The wings 
were Inrought close to the sides of the body. It was impossible 
to remove much of die bituminous matter from the back and 
wings, without injuring the mummy ; but I took away a quasH 
tity sufficient to show that the plimiage was wlute, the feathers 
bdmg tipped with dark brown at their extr^ntties ; I could 
not, however, uncover the tail feathers, so as to determine their 
colour. The bird had attsdned its full growth ; for the qidUs of 
one wing, which had sufiered son» injury in removing the 
bandage, were in a perfect state : the largest of these quills is 
delineated, of the natural size, in the uuiexed Plate. The 
following are the dimensions of such parts of the Ibis as are 
accessible. 

Lengdi of the bird, from the tenmnation of the nedk ^^^^ 
to the extremity a( the tail - • « . is| 

Length of the neck, in which ten vertebrae can be 
traced • . - - - • g^ 

Length of the head and bill, following the curve - 8 

Mm s 



s68 Mr. Pearson's Account of two Mummies 

Inches. 

Length of the sternum - - - - 4 

From the end of the metatarsal bone to the extremity 
of the longest toe - - - - "7 

The longest toe - - - - Sa 

Width of the body at the shoulders - •4a 

Circumference of the body , at its thickest part - 13 j- 
Weight of the mummy, 16^ ounces Troy. 
This mummy is in a very firm and intire state, exhibiting 
no particular marks of decay, although it is probable, that the 
greater part of 3000 years has elapsed since it was interred ; 
for the destruction of the Egyptiani Thebes is of an earlier 
date than the foundation of any city now existing. The ap- 
pearance of the mummy renders it probable, that the bird was 
immersed in the bituminous- matter, when it was in a liquid 
state, and capable of insinuating itself into all the inequalities 
on the surface of the body ; the several folds of the bandage 
must have been likewise covered with the same varnish : but 
the animal was certainly not boiled in the liquid, s^ Grew 
supposed,* since the feathers are not at all corrugated, nor 
indeed materially changed from their natural appearance. 

The examination of different mummies of the Ibis proves indu- 
bitably that the same care has not been used, nor have the same 
methods been followed, in the preparing of them ; but, whether 
the difference observed depended upon the condition of the 
bird when it was embalmed, or upon the unequal skill and 
diligence of the operators, cannot now be ascertained. This, 
however, is sufficientty evident, that the variety exhibited in 
their appearance does not depend on the place where the bird 
was deposited, since many mummies of bbds have been taken 

* MuuBum Regalis SodeiatiSt | i» 



tjf the Egyptian Ibis. itSg 

from the catacombs at Thebes, in as imperfect and decayed a 
condition as those which have been procured from Saccara. 

I have been favoured with the permission to unroll another 
mummy of the Ibis, also sent from Thebes by Major Hayes, 
which had been embalmed in a different manner from that 
I have already described. The cloth which surrounded it 
was of a coarser texture, and had not been so thoroughly 
imbued with bitumen, nor was the roller continued down to 
this body of the bird ; for> when I had removed as much of the 
bandage as reduced the mummy to about y of its original 
bulk, I found that, instead of circular bands, it was wrapped in 
several different portions o£ coarse linen cloth, each of them 
large enough to contain the whole Ibis. This Ibis was in a 
decayed state, and had so little coherence, that its several parts 
separated on handting it : there was a small portion of the 
neck, with white plumage upon it, remaining, but neither the 
head, the bill, nor any remains of them, could be discovered; 
The feathers of this bird are of a dark brown colour, in some 
parts tipped with white ; the neck and the tail have a white 
plumage, and as much of the tail as could be preserved dis- 
played the tufted appearance delineated in* the engraving of 

M. CUVIER. 

Two species of the Ibis, the black and the white, have been 
noticed by Herodotus,* Aristotle,"^ and Pliny : J but Plu- 
tarch has only mentioned the white Ibis.§ Aristotle and 
Pliny have contended that the black Ibis was found only at 
Damietta, ( Pelusium, ) and that, in all the other parts of Egypt, 
the white Ibis only was seen. Whether the two birds which I 

* Euterpe. f Hist. Animalium, lib. be. c. xxviu 

t C. Pit VII Vat.Hh^ lib* x. c. xxx. % Be I side el Osiride. 



S79 Mr. Pearson's Account of two Mummies 

have described present specimens of the black and white IIms, 
I cannot presume to determine. The anterior layer of feathers 
of the Ibis last examined is of a dark colour ; but the {dumage 
beneath is white. Many of the dark feathers are not at all 
marked with white. 

The most ancient, and probably the most authentic acoount 
which we possess of the Egyptian art of embalming, ia deln 
vered by Herodotus ;* and what is oflFered upon this 'subject 
by subsequent writers^ seems to have been copied from this 
^arly hisfoiiaQ. Their narratives relate principally to the ccn<- 
^rvation <^ hunun bodies ; and, in the preparing of these, it 
appears that the contents of the abdomen, at least, were ra^ 
^qvq4 by ip(:i8iQn, or were corroded by injecting a liquor 
#3(tr9iQte4 from: ti^ c^dar^-tree.'t But it is almost certain, that 
birds were not previously opened, nor was any art employed 
tp remove ^«i stomach snd intestmea ; for, on examkung the 
Ulterior psprts of the dark coloured Ibis, I met with a soft 
sipcngj substance^ lying qtiite loose, containing a great number 
of sgaraba^i in w imperfect state ; the&e had probably been 
taken «ts the foQcl of the bird, and were not digested at the 
lime of ita ^sith, ^t remained in the atinenkary canal to the 
present period. Cuvier also remarks, that he found: widiin the 
ip^umn^y of a^ Ibis patt of the skm and scales of a serpent. 
. As larvae of d^noestsd^st and other insects have been d^»cbed 
am^Bg ^ du$t amd boiws of a mummy, it may be presumed 
t;^2i,t the IMs w^ not nlwaya embafaned in a fresh state; whidh 
jfusky qjidi^Qd 9fif^Qim%^ » purtu for the very imperfect condicion 
in wbtch 9i wy ef these, birds, are found. 

The Ibis was held in great veneration by the Egyptians for 



J*i!cs.7hins'i£OCCCVJVa/tyVa.p ijo. 



oj the Egyptian Ibis. 271 

its singular utility in destroying serpents, and other noxious 
reptiles : * hence, the figure of this bird is seen on many mo- 
numents of Egyptian antiquity, as an inhabitant of their tcmpiev, 
and an attendant on their sacrifices.*!* It was likewise em- 
ployed as a symbol in their hieroglyphical writing ; J and the 
punishment of death was inflicted on those who killed this 
sacred bird. The other extraordinary qualities ascribed to the 
Ibis by Pliny, Plutarch, and some succeeding writers, are 
either too indistinctly expressed to be quite intelligible, or t0O 
obviously absurd to be credible. §r 



Explanation of Plate VIU* 

A, Vertetrraeoftheneck. 

B, The head. 

C, The bill. 

D, The tail. 

E, The right leg^ and f(yot. 

F, The left leg and foot. 

G, The hindf claw bent forwards 
H, The sternum. 

I, A cjuiil of the wing feather*. 

The whote is^ represented of the natural size. 

* Tfafr vmark of Cmiro oit thb subject, is perhap» dt tess true than shrev^d : 
^* Ipsi» qui uridentur, £gyptii« nuilam belluaoi^ nisi ob aliquam utilitatem, quam ex 
«' ea caperentj consecraTenint/' De Natura Deorum, lib. k 

f ExpUcathn dt divers Monumens smguliersM Calmbt. 

t ISercgtypb. Horupalbf, xxxri. RiioDidiif. Antiq. LecK lib. ir. c xW, 

§ C. Plimi^ 2£tf/; HuL lib, viiu c. xxvii.^ Ps.uta.&ch. Ds- Ulde^ &c 



C *7»3 



XIX. Observations on the singular Figure of the Planet Saturn* 

By WilUam Herschel, LL. D. F. R. S. 



9 • 

Read June 20, 1805. 

< 

There is not perhaps another object in the heavens that 
presents us with such a variety of extraordinary phenomena 
as the planet Saturn : a magnificent globe, encompassed by a 
stupendous double ring: attended by seven satellites: orna-* 
mented with equatorial belts : compressed at the poles : turning 
upon its axis : mutually eclipsing its ring and satellites, and 
eclipsed by them : the most distant of the rings also turning 
upon its axis, and the same taking place with the farthest of 
the satellites : all the parts of the system of Saturn occasionally 
reflecting light to each other : the rings and moons illuminating 
the nights of the Satumian : the globe and satellites enlight- 
ening the dark parts of the rings : and the planet, and rings 
throwing back the sun's beams upon the moons, when they 
are deprived of them at the time of their conjunctions. 

It must be confessed that a detail of circumstances like these, 
appears to leave hardly any room for addition, and yet the 
following observations will prove that there is a singularity 
left, which distinguishes the figure of Saturn from that of all 
the other planets. 

It has already been mentioned on a former occasion, that so 
far back as the y c ar 1 776 I perceived that the body of Satiirn 
was not exactly round; and when I found in the year 1781 



Dn Herschel's Observations, &c. 273 

that it was flattened at the poles at least as much as Jupiter, I 
was insensibly diverted from a more critical attention to the 
rest of the figure. Prepossessed with its being spheroidical, I 
measured the equatorial and polar diameters in the year 1789, 
and supposed there could be no other particularity to remark 
in the figure of the planet. When I perceived a certain irre- 
gularity in other parts of the body, it was generally ascribed 
to the interference of the ring, which prevents a complete view 
of its whole contour; and in this error I might still have 
remained, had not a late examination of the powers of my lOr 
feet telescope convinced me that I ought to rely with the 
greatest confidence upon the truth of its representations of the 
most minute objects I inspected. 

The following observations, in which the singular figure of 
Saturn is fully investigated, contain many remarks on the rest 
of the appearances that may be seen when this beautiful planet 
is examined with attention ; and though they are not imme- 
diately necessary to my present subject, I thought it right to 
retain them, as they show the degree of distinctness and pre- 
cision of the action of the telescope, and the clearness of the 
atmosphere at the time of observation. 



April 12, 1805. With a new 7-feet mirror of extraordinary 
distinctness, I examined the planet Satum. The ring reflects 
more light than the body, and with a pQwer of 570 the colour 
of the body becomes yellowish, while that of the ring remains 
more white. This gives us an opportunity to distinguish the 
ring from the body, in that part where it crosses the disk, by 
means of the difference in the colour of the reflected light. I 
saw the quintuple belt, and the flattening of the jSbdy at the 

MDCccv. N n 



«74 ^- Herschel's Obwvations 

polar regions ; I could also perceive the vacant space between 
the two rings. 

The flattening of the polar regions is not in that gradual 
manner as with Jupiter, it seems not to begin till a:t a high 
latitude, and there to be more sudden than it is towards the 
poles of Jupiter. I have often made the same observatioii 
before, but do not remember to have recorded it any V^here. 

April 18; 10-feet reflector, power 300. The air is very 
favourable, and I see the planet extremely well defined. The 
shadow of the ring is very black in its extent over the dtek 
south of the ring, where I see it all the way with great dis- 
tinctness. 

The usual belts are on the body of Saturn ; they cover a 
much larger zone than the belts on Jupiter generally take up, 
as may be seen in the figure I have given in Plate IX. ; and 
also in a former representation of the same belts in 1794,.* 

The figure of the body of Saturn, as I see it at present, is 
certainly different from the spheroidical figure (rf Jupiter. The 
curvature is greatest in a high latitude. 

I took a measure of the situation of the four points of the 
greatest curvature, with my angular micrometer, and power 
527. When the cross <d the micrometer passed through all 
the four points, the angle which gives the doulde .Latitude of 
two of the points, one being north the other isouth of the littg) 
or equator, was 93'' 16'. The latitude therefore of the fewr 
points is 4^ 38' ; it is th^e the greatest curvature takes plaoe. 
As neither of the cross wires can be in the parallel, it makes 
the measure so difficult to take, that very great accuracy can* 
not be expected. 

• Sec Phil. Tiwn. for 1794, Table VI. page 31, 



on the singular Figure of the Planet Saturn. 275 

^The most northern belt comes up to the place where the 
ring of Saturn passes behind the body, but the belt is bent in a 
contrary direction being concave to the north, on account of 
its crossing the body on the side turned towards us, and the 
north pole being in view. 

There is a very dark, but narrow shadow of the body upon 
the following part of the ring, which as it were cuts off the 
ring from the body. 

The shadow of the ring on the body, which I see south of 
the ring, grows a little broader on both sides near the margin 
of the disk. 

The division between the two rings is dark, like the vacant 
space between the ansae, but not black like the shadow I have 
described. 

There are four satellites on the preceding side near the ring ; 
the largest and another are north-preceding ; the other two 
are nearly preceding. 

April 19. I viewed the planet Saturn with a new 7-feet 
telescope, both mirrors of which are very perfect. I saw all 
the phenomena as described last night, except the satellites, 
which had changed their situation ; four of them being on the 
following side. This telescope however is not equal to the 10- 
feet one. 

The remarkable figure of Saturn admits of no doubt : when 
our particular attention is once drawn to an object, we see 
things at first sight that would otherwise have escaped our 
notice. 

10-feet reflector, power 400. The night is beautifully clear, 
and the planet near the meridian. The figure of Saturn is 
somewhat like a square or rather parallelogram, wi^ the four 

N n a 



276 Dr. Herschel's Observations 

comers rounded off deeply, but not so much as to bring it to 
a spheroid. I see it in perfection. 

The four sateUites that were last night on the preceding, 
are now on the following side, and are very bright. 

I took a measure of the position of the four points of the 
greatest curvature, and found it 91° 29'. This gives their lati- 
tude 45'' 44',5. I believe this measure to be pretty accurate. I 
set first the fixed thread to one of the lines, by keeping the 
north-preceding and south-following two points in the thread ; 
then adjusted the other thread in the same manner to the 
south-preceding and north-following points. 

May 5, 1805. I directed my sio-feet telescope to Saturn, 
and, with a power of about 300, saw the planet perfectly well 
defined, the evening being remarkably clear. The shadow of 
the ring on the body is quite black. All the other phenomena 
are very distinct. 

The figure of the planet is certainly not spheroidical, like 
that of Mars and Jupiter. The curvature is less on the equator 
and on the poles than at the latitude of about 45 degrees. 
The equatorial diameter is however considerably greater than ' 
the polar. 

In order to have the testimony of all my instruments, on die. 
subject of the structure of the planet Saturn, I had prepared 
the 40-feet reflector for observing it in the meridian. I used a 
magnifying power of 360, and saw its form exactly as I had 
seen it in the 10 and 20-feet instruments. The planet is flat- 
tened at the poles, but the spheroid that would arise from this, 
flattening is modified by some other cause, which I suppose to 
be the attraction of the ring. It resembles a parallelogram, one 
side whereof is the equatorial,, the other the polar diameter. 



on the singular Figure qfthe Planet Saturn. 277 

with the four corners rounded off so as to leave both the 
equatorial and polar regions flatter than they would be in a 
regular spheroidical figure. 

The planet Jupiter being by this time got up to a consi- 
derable altitude, I viewed it alternately with Saturn in the 10- 
feet reflector, with a power of 500. The outlines of the figure 
of Saturn are as described in the observation of the 40-feet 
telescope ; but those of Jupiter are such as to give a greater 
curvature both to the polar and equatorial regions than takes 
place at the poles or equator of Saturn which are compara- 
tively much flatter. 

May 12. I viewed Saturn and Jupiter alternately with my 
large 10-feet telescope of 24 inches aperture ; and saw plainly 
that the former planet differs much in figure from the latter. 

The temperature of the air is so changeable that no large 
mirror can act well. 

May 13. lo-feet reflector, power 300. The shadows of the 
ring upon the body, and of the body upon the ring, are very 
black, and not of the dusky colour of the heavens about the 
planet, or of the space between the ring and planet, and be- 
tween the two rings. The north-following part of the ring, 
close to the planet, is as it were cut off by the shadow of the 
body ; and the shadow of the ring lies south of it, but close to 
the projection of the ring. 

The planet is of the form described in the observation of the 
40-feet telescope ; I see it so distinctly that there can be no- 
doubt of it. By the appearance, I should think the points of 
the greatest curvature not to be so far north as 45 degrees. 

The evening being very calm and clear, I took a measure: 



tyS Dn Hehschel's Observaiions 

of their situation, which gives the latitude of the greatest cur- 
vature 45** si'. A second measure gives ^jS*" 41'. 

Jupiter being now at a considerable altitude, I have viewed 
it alternately with Saturn. The figure of the two planets is 
decidedly different. The flattening at the poles and on the 
equator of Saturn is much greater than it is on Jupiter, but the 
curvature at the latitude of from 40 to 48"* on Jupiter is less 
than on Saturn. 

I repeated these alternate observations many times, and the 
oftener I compared the two planets together, the more striking 
was their different structure. 

May «6. 10-feet reflector. With a parallel thread mkro- 
meter and a magnifying power of 400, 1 took two measures of 
the diameter of the points of greatest curvature. A mean of 
them gave 64,3 divisions = 11'' ,98. After this, I took also two 
measures of the equatorial diameter, and a mean of them gave 
60,5 divisions = 1 1^,27 ; but the equatorial measures are pro- 
bably too small. 

To judge by a view of the planet, I should suppose the 
latitude of the greatest curvature to be less than 45 degrees. 
The eye will also distinguish the difference in the three dia- 
meters of Saturn. That which passes through the points of the 
greatest curvature is the largest ; the equatorial the next, and 
the polar diameter is the smallest. 

May 27. The evening being very favourable, I took again 
two measures of the diameter between the points of greatest 
curvature, a mean of which was 63,8 divisions = 1 1'',88. 
Two measures of the equatorial diameter gave 61 ,3 dhriaans 
= ii'',44. 



an the smgular Figure of the Planet Saturn. S79 

Jfune 1. It occurred to me that a more accurate measure 
might be had of the latitude in which the greatest curvature 
takes place, by setting the fixed thread of the micrometer to 
the direction of the ring of Saturn, which may be done with 
great accuracy. The two following measures were taken in 
this manner, and are more satisfiictory than I had taken before. 
The first gave the latitude of the south-preceding point of 
greatest curvature 43'' 36'; and the second 43* 13'. A mean of 
the two will be 43° 20'. 

June 2, I viewed Jupiter and Saturn alternately with a mag- 
nifying power of only 300, that the convexity of the eye-glass 
might occa.sion no deception, and found the form of the two 
planets to differ in the manner that has been described. 

With 200 I saw the difference very plainly ; and even with 
t6o it was sufficiently visible to admit of no doubt. These low 
powers show the figure of the planets perfectly well, for as 
the field of view is enlarged, and the motion of the objects in 
passing it lessened, we are more at liberty to fix our attention 
upon them. 

I compared the telescopic appearance of Saturn with a figure 
drawn by the measures I have taken, combined with the pro- 
portion between the equatorial and polar diameters determined 
in the year 1789;* and found that, in order to be a perfect 
resemblance, my figure required some small reduction of the 
longest diameter, so as to bring it nearly to agree with the 
measures taken the 27th of May. When I had made the ne- 
cessary alteration, my artificial Saturn was again compared 
with the telescopic representation of the planet, and I was then 
satisfied that it had all the correctness of which a judgment of 

• Sec Phil, Trans, for 1790* page ij. 



t8o Dr. Herschel's Observations, &a 

the eye is capajble. An exact copy of it is given in Plate IX. 

The dimensions of it in proportional parts are, 

The diameter of the greatest curvature - 36 
The equatorial diameter - - - 35 

The polar diameter - - "" . " 3^ 

Latitude of the longest diameter - - 43** 20'. 



The foregoing observations of the figure of the body of 
Saturn will lead to some intricate researches, by which the 
quantity of matter in the ring, and its solidity, may be in some 
measure ascertained. They also afford a new instance of the 
effect of gravitation on the figure of planets ; for in the case 
of Saturn, we shall have to consider the opposite influence of 
two centripetal and two centrifugal forces : the rotation of both 
the ring and planet having been ascertained in some of my 
former Papers. 



Ikilos.Tmn^MD C C CY.Plaie IX .p. %8o. 




C280 



XX, On the magnetic Attraction of Oxides of Iron. By Timothy 

Lane, Esq. F. R. S. 



Read June so, 1805. 

JtIaving found by experiment, that hardened iron is not so 
readily attracted by the magnet as soft iron, and that needles 
are inferior to iron wire as indexes to Six's thermometer, I 
was proceeding to other comparative experiments, when I re- 
ceived the Second Part of last year's Philosophical Transactions, 
in which I saw an Analysis of magnetical Pyrites, with Remarks 
on Sulphurets of Iron, by Mr. Hatchett. 

This Paper led me to examine what magnetical properties 
iron possessed, when free from inflammable matter. For this 
purpose I obtained a precipitate of iron, prepared and sold at 
Apothecaries' Hall by the name of Ferrum pracipitatum. Mr. 
Moore, the chemical operator, informed me, that he pre- 
pared it by dissolving twelvis pounds of sulphate of iron in 
twenty-four gallons of distilled water, and then adding eight 
ounces of sulphuric acid to render the solution more ODmplete. 
Twelve pounds of purified Icali were mixed with the solution : 
the precipitate was weir washed with hot distilled water, and 
then carefully dried. This precipitate is similar to the sediment 
of chalybeate waters; and affords no magnetic particles; nor, 
when exposed to a continued clear red heat, does it suffer any 
. alteration beyond the acquirement of a darker colour. But if 
any smoke or flarae has access to it, then magnetig particles 

MDCCCV. O o 



t 
i 



«83 Mr. Lane on i)ie thdgnetic Attraction 

are evident. Heat, by the converging rays of the sun,* equal 
to that at which glass melts, blackens the oxide, but does not 
render it magnetic, if free from any inflammable matter. It is 
requisite, in this experiment, to protect the oxide, by glass, 
from the dust floating in the air, which otherwise will render 
many of the particles magnetic. I attributed this effect to the 
deoxidising property of light, till by eifiploying a protecting 
glass, the result proved it to proceed from the dust in the 
atmosphere. 

By repeated ^experiments i fcnmd, that heat alone produced 
no magnetic effect on the oxifle, and that inflammable matter 
with heAt always rendered some of the particles itaagnetic. 

As the inflkniriiaHe mitter in roal had this eflfect, I mixed 
some oT the oxide with a portion of coal in a glass mortar, and 
continued rubbing them together for some time without any 
magnetic eflfect. The ihixture was then plit 'into a tdbadco- 
pipe, and placed in 'the dear red lieat of a coftimon fire ; -as 
soioh as the pipe had ^acquired a red heat, it ^vas taken out. 
The mixture was put on a glasred tile ^to cool, and proved 
h^hly magnetic. 

I riiBbed a portion of the original oxide in a gliss ihortar 
with Ti variety of 'substances, as sulphur, charcoal, camphor, 
ether, alcohol, &c. and found that no eflfect was produced 
without the istssistance of heat. The heat of boiling water, 
moreover, ivas'riot isuflBcient ; biit by tlieheat of meltii^ kiKl 
I procured magnetism. Small quantities of any inflammable 
matter in a red heat have an evident eflfect on the dxide. 
Nfydrogen^ aided by a red heat, renders the oxide magnetic, 

* The lens err ployed in this experiment was twelve inches ia dia[AeUr,'ahd'tlie 
libifat its fbtvis^Wts stxffitient to Aelt iron ; from Mr.^DoA lon o* 



w^ter, vth9ugh.it xxjay.flaBie in t^ie fire,,it v^in^e/nfif^tu^l,.^s 
it is driven off before t)ie oxide becpinejs su^jenti^ heated to 
receive . i^ . action. 

^di ajjtnbq&tible substances, ^s do not very .^eadily .ps^rt 
'Withr their qarjlTaiiiceleinient, require rathi^rjl^pger w^tujju^aiice 
of he^t than others : for ex^^ple, cljarco^l aijfl dpderjs, well 
burnt, must be Iqi^ger in tlje i^p,tp)l\aye ,th^ir fijll i^gct on 
the oxide, than dry wood, coal, or sulphur. 

But such substances as may be sublimed, with facility, will 
gradually quit the oxide, by a continued application even of a 
low heat, leaving it unmagnetic, as at first. 

How very small a portion of inflammable matter is requisite 
to render a considerable quantity of oxide magnetic, is evident, 
since one grain of camphor dissolved in an adequate portion of 
alcohol, and mixed with a hundred grains of the oxide in a 
glass mortar, will, by a red heat, render all the particles of 
the oxide magnetic. 

As oxides of iron therefore are rendered magnetic by heat, 
when mixed with inflammable matter, it may be imderstood 
why Prussian blue, sulphurets, and ores of iron containing 
inflammable matter, become magnetic by the agency of fire ; 
while at the same time it is observable, that these same ores 
revert to their unmagnetic state, when the heat has been con- 
tinued sufficiently long to drive off the whole of the inflammable 
matter : thus we find among the cinders of a common fire cal-- 
cined sulphurets of iron, distinguishable by their red colour, 
unmagnetic when all the sulphur is sublimed. 

My intention in this communication is to prove generally 
that mere oxides of iron are not magnetic ; that any inflam^ 

Oo 8 



284 Mr. Lane on the magnetic Attractiony &c, 

mable substances, mixed with them do not render them mag- 
netic, until they are by heat chemically combined with the 
oxides, and that when the combustible substance is again 
separated by heat, the oxides return to their unmagnetic state. 
That magnetic oxides cannot be distinguished from calcined 
oxides by their colour, I entertain a hope, however, that this 
subject may be found worthy of the accurate investigation of 
some other member of this learned Society. 



k 



C»ss3 



XXL Additional Experiments and Remarks on an artificial Sulh- 
stance J zvhich possesses the ptincipal characteristic Properties of 
Tannin. By Charles Hatchett, Esq. F. R. S. 



Rsad June 27, 1805. 

§1. 

WuEii I had ascertained that carbonaceous substances, whether 
vegetable, animal, or mineral, were capable of being converted 
into a product, which, by its effects on earthy and metallic 
solutions, on dissolved gelatine, and on skin, resembled the 
natural vegetable principle called Tannin , I was at first inclined 
to give it the name of artificial or- factitious tannin ; but some 
eminent chemists of this country, for whose opinions I have 
the highest respect, considered this name as objectionable ; for 
although the artificial substance resembles tannin in the parti- 
culars above stated, yet in one character there appears to be a 
very considerable difference, namely, the effect of nitric acid ; 
for . by this, the artificial substance is produced, whilst the 
varieties of natural tannin are destroyed. Such an objection, 
sanctioned by such authority, induced me to alter the title of 
my Paper, and to expunge the word tannin wherever it had 
been applied to the artificial product. 

In order to satisfy myself more fully on this point, I have, 
since the communication of my former Paper, made a few ex- 
periments on the comparative effects produced by nitric acid 



«86 Mr. Hatchett'b additional Experiments 

on those substances which contain the most notable quantities 
of tannin y and of these I shall now give a succinct account, and 
shall also cursorily notice other e^eriments, 'in^whld^ a [tan- 
ning substance has beenproduced^umder drcurAstanoes dtfieMnt, 
in some measure^ from those which have been alraady.desoribed. 

§11. 

Although I cannot «is '^yet assert, that i the artificial tanning 
product is absolutely indestructible when repeatedly distilled 
with different portions of nitric acid, yet the following experi- 
ments will prove, that the destructibility of it by this method 
must at least' be a work of considerable time* and ^fficulty. 

1 . Twenty-grains of this substance were ^iss^lved in* half 
^ ounce of strong nitric acid, the specific gravity ofwiiich 
wis 140. The solution was then subjected to distillation «ntil 
the \Vhole of the acid had come over, after which, * it -was 
poured back upon the residuum, and the distillation was thus 
repeated three times. 

Gare was taken not to overheat the residuum, and this, vA\&\ 
examined, did not appear to have suffered alterafion ^in any Of 
its properties. 

2. Ten grains of the artificial tanning substaneeymix^d- with 
ten grains of white siigar, were dissolved in half an ounge of 
liitric acid, and the whole was distilled to dryness. 

The residuum being then dissolved in bdling distilWd water, 
and examined by solution of gelatine and other reagents, was 
found to be unchanged in every respect. 

3. This resembled the former, only that gum arabic was 
employed in the place of sugar. The result was the same* 

4. A qiiantity of dissblved isinglass was preeipitated by. a 



on a Subrt0^e possessing the Pr&peHies OjT Tannin. 987 

aolutioi!! c^ the artificial tanning substance, and the precipitate 
having been well washed with hot distilled water, was after- 
wards gradually dried. It was then digested in strong nitric 
acid, which after some time acted powerfully upon it ; much 
nitrous gas was evolved, and a dark brown solution was 
formed. This was evaporated to dryness, and after having been 
completely dissolved in boiling distilled water, was examined 
by nitrate of lime, acetite of lead, muriate of tin, and solution 
of isinglass, all of which formed copious precipitates, similar 
m every respect to /those produced by the artificial tanning 
sufoiAance, which had not been subjected to the above described 
process. 

5. A portion of the predpitate, farmed by isinglass and the 
tanning substance, was dissolved in pure muriatic acid, and 
was afterwards evaporated to dryness. Boiling distilled water 
dissolved only a small part, and the solution, which was of a 
dark beer colour, did not precipitate gelatine, although it acted 
%ipon muriate of tin, and sulphate of iron ; for witii the former 
it produced an ash-coloured precipitate, and with the latter a 
slight deposit of a reddish-brown colour. 

6. As so small aipart of the predixtated isinglass had been 
thus rendered soluble in boiling water, the residuum was 
treated with nitric acid, as in experiment 4, after which, being 
evaporated to dryness, it was found to Jbe completely soluble 
in water, and predfMtated gelatine as copiously as at first. 

7. I dissolved to grains of the pure tanning substance in 
^bout half ' an ounce of muriatic acid ; Jbut, aft^r distillation to 
4r^)eas, ^Uie residuum in every respect appeared to be un« 
i^Kuiged. 



f88 Mr. Hatchet's Additional Experiments 

In addition to the above experiments may be added, that the 
solutions of the artificial tanning substance seem to be com- 
pletely imputrescible, neither do they ever become mouldy like 
the infusions of galls, sumach, catechu, &c. 

Having thus ascertained the very unchangeable nature of this 
substance, I made the following comparative experiments on 
galls, sumach, Pegu cutch, kascutti, common cutch, and oak 
bark. 

" 8. Twenty grains of powdered galls were dissolved in half 
an ounce of the strong nitric add ; the solution was then evapo- 
rated to dryness, and the residuum dissolved in boiling water. 
This did not produce the smallest effect on dissolved gelatine. 

9. A strong infusion of galls evaporated to dryness, and 
treated as above, was totally deprived of the tanning property. 

10. Isinglass precipitated by the infusion of galls, was dis- 
solved in nitric acid, and examined as in experiment 4, but no 
trace of tannin could be discovered. 

1 1 . Twenty grains of sumach were dissolved in half an ounce 
of the strong nitric acid, and treated as in experiment 8, after 
which it appeared that the tannin was destroyed. . ' 

1 fi . Twenty graints of Pegu cutch ( which contains a consi- 
derable quantity of mucilage ) were subjected to a similar 
process, by which much oxalic acid was obtained, but . every 
vestige of tannin was obliterated. 

13. Twenty grains of the catechu called Kascutti afforded 
results similar to the above. 

1 4. Twenty grains of the common cutch or catechu being dis* 
solved in nitric acid, evaporated to dryness, dissolved in water, 
9nd examined by solution of isinglass, rendered the latter 



on a Substance possessing the Properties of Tannin. tSg 

tinrbid,' a tenadau^ film was deposited, which was insoluble in 
boiling watery and wafe evidently coin posed of gelatine an^ 
tannin. • , - 

, 15. Twenty grains of prepared oak bark, by the like treat- 
ment, afibrded a solution in water, which still acted in some 
measure lupon gelatine, as it caused a solution of isinglass to 
become slightly turbid, and a film completely insoluble in 
boiling water was, as in experiment 14, deposited on the sides 
and bottopi of the vessel. 

• 16. Infusions were prepared as nearly as possible of equal 
^OTgth from galls; sumach, shavings of oakwood, oak bark, 
and the artifidai tanning substance ; half an ounce in measure 
of each was tlien put into separate glasses, and one drachm in^ 
measurfeof the strJongnifria add was added. '. 

- The different infusiopi were then examined by solution of 
isinglass, and I fouiidthat those of galls, sumach, and oak wood, 
were not rendered turbid, whilst the contrary happened to the 
infusions of oak bark, and of the artificial substance ; for these 
continued to precipitate gelatine, until four drachms or half an 
ounce- of the nitric acid had been added to each half ounce of 
the infusion. 

When the results of these expcriinents are compared, they 
seem to establish, that although the artificial product is by much 
the most indestructible of all the tanning substances, yet there 
is some difference in this respect even between the varieties of 
natural tannin ; and that common catechu, and the tannin of oak 
bark, resist the effects of nitric acid much longer than galls, 
sumach, kascutti, and Pegu cutch. The last, as I have ob- 
served, is replete with mucilag^e, and by nitric acid yields a 
large quantity of oxalic acid ; it also appears to be the most 

MDCCCV. P p 



3fta ^fir. Hat^hbtt'5 aMttonai Mxperimenff. 

destructible qf all the v^ieties of catechu, and oa Hug account 
I attempted, although without success, to promote the destruco 
tionof the properties of tiie artifidal substance, by adding gum 
ar^bic in one case, and sugar in another, fex diSereitt portions^ 
previous to exposing it to the action of nitric axad. I am. 
however, convinced^ that the presence of gum or mucilage 
in natural substances which cont^n tannm^ renders this more 
speedily destructible by nitric acid, and I shall soon have occa^ 
sion to notice some experiments which tend to prove, iSb^ the 
presence of gum or mucihtge in ce^^tain bodies, aiso prevents 
pr impedes more or less the formation of the artifidai tanning 
substance. The cause of this di&rence I am ixsclined to sufr*. 
pect is, &at in those bocfies the gum or mudlage is not simpIy^ 
mixed, but is present in. a state of chenjdcal combinatioci, by 
tvhicb, certain modificadonB produced by the action of nitric acid 
Upon the elementary pnncipl^s of the original substance becpzne: 
&cilitated; 

■ 

A. When sulphuric acid was added to, a solution of the artl&* 
dal tanning substance, the latter became turbid, and a copiou^; 
brown, predpitjate subsided, which WW soluble in boiling dis- 
tilled water, and then was capable of {wedpitating gelatinp. 

B. The same efiect was pixxlucedby murialic add,; so thftt 
in these particulars, the artifidal tanning substance was founds 
to resemble piedsely the taanin ot galls, and of other natui^al 
substances.* 

C. Garbonafb of potash, when added to. a solutiicxi of tb& 

• Mr. Diy vr op the Constituent Paru of Astrm|;cnt Vegetables, Phil. Trans. iSoj* 
p: 240/ 241. 



on a Substance possessing the Properties o/" Tannin. «gi 

^artificitil tanning sufoststnce, deepens die colour^ aftei* \ciiicli^ the 
solution becomes turbid and deposits a brown niagma. 
" D. Five grains of the dry substance were dissolved in half 
9n ounce of strong ammonia ; the whole was then evaporated 
to drjrn^ss, and being dissolved in water, wsLs found not to 
precipitate gelatine, unless a small portion of muriatic add was 
previously added. 

£. Another portion of the same substance which had beien 
dissdlved in ammonia wais evaporated in a long necked matrass, 
and was kept in Very hot sand during half an hour ; at first 
fiome ammonia arose, arid afterwards a yellow liquor which 
had the odour of burned horn. The x^siduum was theti ex- 
amined, and was foiirid to be nearly insoluble in water, to whic^ 
it only communicated a sKght yellow tinge. 

F. It is remarkable, that the dry artificial tailniilg substance, 
although prepared from vegetable matter, should, when placed 
<m a hot iron, emit an odour very arialogous to burned animal 
substances, such as horn, feathers, &c. ; this I found also to be 
the ca£(e in the experiment which has bden related, and I was 
desirous therefore to aseertaki mdre ajccurately the effects of 
heat cm this substance when distilled in close vessels. 

I took some very pure vegetable charcoal which hiad been 
exposed to a red heat in a retort for mote than an hbur, aind 
by nitric acM converted it into the artificial tasrmmg substance* • 

Twenty grains of this, rendered as dry as possible, wef e 

put into a small glass retcnrt, t^ which a proper nppiritas ter- 

nunatii^ lA a jar filled with quick^lver and inverted in a mer-^ 

curial trough was adapted. The retort was placed in a small 

furnace, and was gradually heated by a charcoal fire iiuitil ^he 

bulb became red hot 

Pp2 



293 Mr. Hatchett's additional Experiments 

When the retort became warm, and after the expulsion of 
the atmospheric air, a very small portion of water arose, which 
settled like dew on the sides of the vessels ; this was succeeded 
by a little nitric acid, from which the tanning substance had 
not been completely freed, and soon after a yellowish liquor 
came over, which was in so very small a quantity as only to 
stain the upper part of the neck of the retort : as nothing more 
seemed to be produced, I then raised the lire, when suddenly 
the vessels were filled with a white cloud, and so great a por- 
tion of gas was almost explosively produced, as to overseft the 
jar ; this gas, by its odour, appeared to be ammonia, which in 
the first instance had formed the white cloud, by combining 
with the vapour of the nitric acid with which the vessels were 
previously filled.* Another jar was speedily placed in the 
room of that which had been overturned, and a quantity of gas 
was slowly collected ; this proved to be carbonic acid, except- 
ing a very small part, which was not tarkeh up by solution of 
caustic potash, and which as far as the smallness of the quan- 
tity would permit to be determined, appeared to be nitrogen 
gas. There remained in the retort a very bulky coal, which 
weighed eight grains and a half ; this by incineration yielded 
one grain and a half of brownish white ashes, which consisted 
principally of lime, but whether any alkali was also present I 
cannot positively assert, as the trace which I thought I discovered 
of it was very slight. 

I shall for the present postpcme any remarks upon this expe- 
riment, as I wish to proceed in the account of others which 
have been made on die artificial tanning substance. 

G. Fifty grains of this substance were dissolved in four 

* After the experiment the receiver wa& found to be thinljp coated with a white saline 
crust* 



on a Substance posseting the Properties of Tannin. 2^5 

ounces of water, and were afferwards precipitated by dissolved 
rsinglass, eighty^ne grains of which became thus combined 
with forty-six grains of the tanning substance. 

The remaining portion of the latter was not precipitated, and 
was therefore separated by a filter, and evaporated to dr)mess. 
It then appeared in the state of a light brittle substance of a pale 
cinnamon brown colour ; and it is very singular, that although 
charcoal is an inodorous body, and although the artificial tan- 
ning substance, when properly prepared, is likewise devoid of 
smell, (unless a certain pungent sensation which may be per- 
ceived lipon first opening a bottle containing the powder after 
agitation should be so termed, but which seems rather to be a 
mechanical effect ) yet this substance possessed a strong odour 
not very unlike prepared oak bark, and this odour became much 
more perceptible when the substance was put into water, in 
which it immediately dissolved. The solution was extremely 
bitter, and acted but slightly on dissolved isinglass, with which^ 
however, it formed some ilocculi ; vsnth sulphate* of iron^ it pro- 
duced a brown precipitate ; with muriate of tin one which was 
blackish brown ; nitrate of lime had not any effect ; but acetite, 
of lead occasioned a very copious precipitate of a pftle brov^Ti 
colour. This substance therefore appeared to be a portion of 
the tanning matter so modified, as partly to possess the charac- 
ters of extract.* 

Other experiments were made on the tanning substance pre- 
pared from various bodies, which by the dry and by the humid 
way had been previously reduced to the state of coal ; but these 
I shall here omit, and shall pass to the description of a series of 

* When added to a solution of carbonate of ammonia^ it produced some efFcrres* 
ceace> but its peculiar vegetable odour did not suffer, any diminution. 



«iM ^^ Hatchktt^s adiUtianal Exptrinuntu 

lexpenntents, by whick I olitained a variety of tiie artificial taii- 
ining substance in a way diiferent from that which has bettl 
related, and with which I was unacqaainted when my fortner 
]xaper was written. 

§rv. 

I made several unsuccessful attempts to form the artificial 
:substance by means of oxymuriatic acid, and it therefore ap- 
peared certain, that although a variety of the tanning matter 
could be produced by the action of sulphuric add on resinous 
substances, yet Ae most effective agent was nitric add, which 
readily formed it when applied to any sort of coal. 

But I nevertheless suspected, that possibly tlds substance, or 
something similar to it, might be produced without absolutely 
convertmg vegetable bodies into coal ; for it seemed, as I have 
observed in my former paper, that this only served to separate 
the carbon in a great measure from the other elementary prin- 
ci{^es ( excepting oxygen ) which were combined with it in the 
original substance, and thus to expose it more oomj^etely to the 
effects of the nitric acid, as well as to prevent the formation of 
the various acid products, which are so constantly afibrded by 
the organized substances when thus treated. At first I had 
some thoughts of employing touchwood in this experiment, but 
not being able immediately to procure any, it occurred to me, 
that indigo might probably answer the purpose ; far from some 
experiments made by myself ^ as well as from those described 
by Bergman,* I well knew that the proportion of carbon in 
tMs substance is very considerable. The following experiment 
was therefore made. 

• Analysis Cbenuca Pigmtnii Indki. OpmcaUi Biro, Tom. V. p« $6. 



o» a SM$flce posseff^ Ike Fr^erides qfTdoxcm. %gs, 

X. Oh one buR<tred grains af ime! iitdigo whidi had been: put 
into 9 Id^ n3atra83, CMne oonce of nkric acid dQated with am 
equal qiiaiititj of water was iioured, and-, as die action of the< 
add WAS almost inuxiedlate aod extremely violent, another 
ounc? of wster was added. When the effervescence had nearly 
subsided, the vessel wa3 placed m » sand-bath durii^ severaSi 
days^ un;til tibe whole of ^ Uquid was evaporated. 

On the residuusEt:, whieh wa9 of a deep orange colour, three 
QiH^Ges of boiling distilled water were poured, l^ whidi a con*- 
sideral^e part was dksaolved. 

Thfi, colour of the solution was a naost beaiMilul deep yeHow^ 
and the bitter flavoor of it siorpassed in intensity that of any 
substance in my reeoUectiQn ; it was; examined by the fbllawing; 

Sulphftte of iron produced a s%ht pale y^ow pred^ate. 

NitiNUte of Uni9 only rendered it a little turbid, after whidr^ 
a snaH portion of wUlte powder subaided, which had the idia^^ 
xactera of oxalate of lunei 

Muriate of tin produced a eopbus white {nreci^tiite, which 
afiberwards. dianged to a jreUo wish<*bro v^/nv 

Acetite of lead formed a very faeautifiil deep lemon*colouredl 
precipitate, which possibly may prove* useful/ as a pigment. 

Amn^oaaaaL rendered the colour mudi deeper^ after which the 
fiquor became turbid, and a large quan^^i ofi fine yellow spi«« 
culated crystala was deposited, which being dissolved in water, 
dkbmt precipitate Ime from ita solutions. 

The flavour of these crystals was very bitter, and I suspect; 
them to be composed of ammonia combined with the bitter 
priQfiq)k first noticed, fay Wslthbiu^ 

* T!uQUtom*% System of Chemistry, 2d edit. Vol. IV. p. z^* 



9q6 Mr Hatchett's additional Experiments 

Lastly, when dissolved isinglass was added to the yellow 
solution of indigo, it immediately became very turbid, and a 
bright yellow substance was gradually deposited, and coated 
the sides of the glass jar with a tough elastic film, which was 
insoluble in boiling water, and possessed the characters of 
gelatine combined with tanning matter. 

By this experiment I therefore ascertained, that a variety 
of the artificial tanning substance could be formed without 
previously converting the vegetable body into coal ; and I have 
since discovered, that although indigo more readily yields this 
substance than most of the other vegetable bodies, yet in fact, 
very few of these can be regarded as exceptions, when sub- 
jected to repeated digestion and distillation with nitric acid. 

2. — ^A. In my former Paper I have stated, that common 
resin, when treated with nitric add, yielded a pale yellow so- 
lution with water, which did not precipitate gelatine, and that 
it was requisite to develope part of the carbon in the state of. 
coal by sulphuric acid, before any of the tanning substahce 
could be produced; but having again made some of these 
experiments, I repeated the abstraction of nitric acid several 
times, and then observed, that the solution of resin in water 
acted upon gelatine similar to the solution of indigo which has 
been described, and formed a tough yellow precipitate^ which 
vvas insoluble in boiling water. 

With other reagents the effects were as follows. 

Sulphate of iron, after i« hours, formed a slight yellow 
precipitate. 

Nitrate of lime did not produce any effect. 

Muriate of tin, after 12 hours, afforded a pale brown preci- 
pitate. 



on a Substance possessing the Properties ofTzxmm, ^q*j 

And acetite of lead immediately formed a very abundant 
precipitate of a yellowish white colour. 

I repeated tliis experiment on common resin, and remarked, 
that during each distillation nitrous gas was produced, whilst 
the strength of the acid which came over was diminished ; the 
cause therefore of the change in the properties of the resin 
seemed to me very evident, and I was induced to extend the 
experiments to various resinous and other substances ; but as 
the process was uniformly the same, I shall only notice the 
principal effects. 

B. Stick lac, when separated from the twigs, and treated as 
above described, copiously precipitated gelatine. 

C. Balsam of Peru during the process afforded some benzoic 
add, and gelatine was precipitated by the aqueous solution. 

D. Benzoin also, after the sublimation of some benzoic acid, 
yielded a residuum, which with water formed a pale yellow 
solution, of a very bitter flavour. 

This solution with sulphate of iron afforded a slight pale 
yellow precipitate. 

With nitrate of lime not any effect was produced. 

The solution with muriate of tin became turbid, and a small 
quantity of brownish- white precipitate subsided. 

Acetite of l^ad immediately produced a copious pale yellow 
precipitate. 

And solution of isinglass formed a dense yellow precipitate, 
which was insoluble in boiling water. 

£. Balsam of Tolu, like Balsam of Peru, and Benzoin, af-- 
forded some benzoic add ; and the residuum being dissolved in 
water, was found to precipitate gelatine. 

F. As the results of the experiments on dragon's blood were 
MDCccv. Q q 



dgS Mr. HatcheTt's additional Experiments 

sometvhat remarkable, 1 shall here more particularly rdate 
them. One hundred grains of pure dragon's blood, reduced to 
powder, W6re digested in a long matrass with one ounce of 
strong nitric acid ; the colour immediately changed to deep 
yellow, mlich nitrous gas was evolved, and to abate the effer- 
vescence, cAe ounce of water was added. The digestion was 
continued until a deep yellow dry mass remained, and the 
matrass being still kept in the sand^bath> a brilliant featfaer-like 
sublimate arose, which weighed rather more than six grains^ 
and had the aspect, odour, and properties of bcM2oic add** 

The residuum was of a brown colour, artd with water formed 
a golden yellow-^coloured solution, which by nitnrte of lime 
was not affected. 

With sulphate of iron it afforded a brownifiii^y«116w prea* 
pitate. 

With muriate of tin the result was similar. 

With acetite of lead a lemoi^oloure it precipitate was 
ptt)duced. 

Gold was precipitated by it in the metallic state^ whilst the 
glass vessel acquired a tinge of purpl* : 

Afid dissolved isinglass produced a d^p yidQow defK>sit, 
which was insoluble in boiling water. 

A portion of the same dragon's blood was «l*ipiy exposed 
to heat in the same matrass, but not any appearance ttf behsoic 
acid ooidd be discovered. I am therefore induced to believe, 

• Accordinjg \o these cxperiihehts, dragon's bl«Kl ought ID be attimgwl trith kcn- 
ioift and the Mstans, htrt os the oamples of this -df ug 4tt Mt atirtys pmMf similar^ 
it would be proper to examine every variety. Thit mhkh wat emptoycd ia my oxpe- 
riments^ wasaporous mass of.a dark red^ and was sent to me by Messrst Ai*liii and 
Howard* of Plough Court* in Lombard Street. 



on a Siuistan£e possessing the Pr^ertififi of Tannin* ^99 

diat m the iirst expennlent it was obtained as a ^oduct^ and 
not as an educt, a fact which as yet has not been suspected. 

G. Glim afflivoniac awarded a brownish yellow solution^ the 
flavour of wldck wias very bitter «nd astringent. 

By sulphate of iron, tWs soluticm only became of a 4arker 
colour, but did not form «iy precipitate. 

Nitrate df Jime rendered it tujrbM, and produced ^ slight 
fxrecipitate. 

Muriate of tin formed a copious yellow precipitate. 

Acetite of lead produced ,a aimilar :efieot : 

And gelatine yielded a ba-ight yellow deposit, whi;Ch was 
^completely insoluble by boiLing water. 

H. Asa foetida yielded a solution which also precipitate^ 
gelatine like the substances abo:v:e described. 

L Solutions of elemi, tacamahac, olibanum, sandarach^ co- 
paiba, mastich, myrrh, gamboge, and >caoutQhouc, were next 
examined, but these, although -they precipitated the metallic 
solutions, did not affect gelatine. It is possible, however, that 
they mi^ht have .produced this elfect, had they been subjected 
to a greater immber of repetitions of the process. 

K. Sarcoool, in its natural state, as well as the gum sepa- 
rated from it by water, when treated with nitric acid, did not 
/precipitate gelatine ; but produced eflfects on the metallic solu- 
tions similar to the above mentioned substances. 

i!U vGum arable afibrded oxalic add, but not any of the 
tanning matter. 

M. Tragacanth yielded an abundance of saclacdc acid, of 
oxalic, and of .malic acid, but not the smallest vestige of the 
artificial tanning substance. 
^. Manna, vdien treated with nitric acid in the way above 



300 Mr. Hatchett's additional Experiments 

described, afforded oxalic add^ part of which was sublimed in 
the neck of the vessel. 

The residuum with water formed a brown solution, which 
yielded a pale yellow precipitate with sulphate of iron. 

Muriate of tin produced a pale brown precipitate. 

Acetite of lead formed one of a brownish-white hue. 

Lime was copiously precipitated from the nitrate of lime in 
the state of oxalate ; but not the smallest effect was produced 
on solution of isinglass. 

O. Liquorice however afforded a different result ; for, al- 
though the solution after the process with nitric add resembled 
in appearance that which was yielded by manna, yet the effects 
were not the same. 

Sulphate of iron, after twelve hours, produced a slight brown 
precipitate. 

Muriate of tin had a similar effect. 

Acetite of lead formed a brownish-red deposit. 

Nitrate of lime also occasioned a brown predpitate : 

And solution of isinglass rendered it very turbid, and pro- 
duced a yellowish-brown precipitate, which was insoluble in 
boiling water, and possessed all the other characters of gelatine 
combined with the tanning substance. 

P. Guaiacum, the properties of which are so singular in 
many respects, afforded results ( when treated with nitric acid 
in the manner which has been described ) different from the 
resins, although its external and general characters seem to 
indicate that it appertains to those boAes. 

Nitric acid acted upon it with great vehemence, and speedily 
dissolved it. The residuum which was afterwards obtained, 
was also found to be almost totally soluble in water> and the 



on a Substance possessing the Properties ^Tannin. joi 

solution acted on the metallic salts like those which have 
already been noticed, but with gelatine it formed only a very 
slight precipitate, which was immediately dissolved by boiling 
water ; and the remainder of the solution being evaporated, 
yielded a very large quantity of crystallized oxalic acid ; so 
that in this respect guaiacum was found to resemble the gums, 
and to be totally unlike the resins.* 



As many vegetable substances when roasted, yield by decoc- 
tion a liquid, which in appearance much resembles the artificial 
tanning matter when dissolved in watejp ; I roasted some of the 
common dried peas, horse-beans^ barley, and wheat flour, the 
decoctions of which however did not afford any precipitate by 
solution of isinglass. 

Even the decoction of coffee did not yield any precipitate by 
this method, until several hours had elapsed, and I found that 
the precipitate so formed wks permanently soluble in boiling 
water. But to expl^n this, we must recollect, it is extremely 
probable, that some peculiar nicety is required in the roasting of 
such bodies before the tanning substance can be developed ; 
and this seems to be corroborated by some experiments which 
I made on the decoction of a sort of coffee prepared from 
the chicoree ( I suppose endive ) root, which was given me by 

* The properties of guaiacum which have been described* as well as those which 
were previously known, appear to indicate, that it is a peculiar substance of a nature 
distinct ^m the resins* balsams, and even the gum resins. 

So remarkable indeed is this substance, that an accurate series of experiments os 
the whole of its properties may justly be placed amongst the chemical desiderata. 



30fc Mr. HatckAtt's additional Experiments 

Sir Joi$£pfi Ba:kks -; for akhougfa tiiis decactVon did not afford 
an imftie<fia*e predpitate with solution of gelatine, and although 
the f>fedpitate was also apparently dissolved by fooiHng water^ 
yet upon feooUtig^ the same pf edpitate was reproduced in its 
original ^tate. I aim t^enefore inclined to "believe, that the 
tanning Bubstance « reaflly developed in many of the vegdtabfe 
bodies by heat, but that a certain degree of temperature, hot 
yery easy to determine, is absolutely requisite for this purpose. 

Before I conclude this section, it may be proper to observe, 
that when a small quantity of nitric acid was added to any of 
the ^fbove^m^tioned deteocticms, and when* these had been 
«ttb&e<Jfle«tly evaporated to dryness, and afterwards dissolved 
in di£rtilled water, they Were converted into a tanning substance 
))erfectly ^milar to that Which is -produced by the actbn of 
taitric add on the vftl?iet*fes of coal, 

In the preceding Paper, a variety uf the tarminj^ sttfastance 
"wbs slightly noticed, which was formed iiy die action of sul* 
]phuric acid upon common resin, elemi, ambar, &c. &c. and 
tis ^n instance itab occurred of the formation of the same sub* 
fetkntee frotn ^a*nphor, accompamed by x:ircurostances which 
%eTha to 4ncrebse our knowledge of the pi^operties of the latter^ 
I -shall here describe this experin>eht. 

Experiment on Camphor with sulphuric Acid. 

The effects produced on camphor by sulphuric add Tiave 
been but very superfidally examined ; for all that has hitherto 
been stated amounts to this, that camphor is dissolved by sul- 
phuric add, that a brown or reddish-brown solution is formed^ 



I 



im a l^ibsUmce posmsi^g the Pr^ptrtUs of Tannin. 503 

afi4 that the camphor is precipitated unchanged flrora this aoh»- 
tion by water. These facts, however, only relate to a certain 
period of the operation, for if this be long contkiued, other 
[eiiects are jn-oduced, which I $hall now describe. 

A. To om hundred graina of pftre (»mphpr put into? a small 
glass alembic, one ounce of concentrated sulphuric acid w^/s 
added. The camphor immediately became yellow, and gra- 
dually dijaolved, during which, the acid progrespiy^iy phanged 
to browhish-red, and afterwards to hto^w. At thjj periQd> 
scarcely any suiphureoui add -was evolved, bat in about onp 
hcmr the Hquid became blackish-browri ; mych sulphureous 
add gas was then produced, and cohtinued to increase during 
four hours, when the whole appeared like a tluek black jdiquid, 
.at which period not any odcmr or appearance of ismnrphor could 
be perceived, but only that of the sulphureous add- After two 
j^xy%^ duraig winch time tihetdiemlac hod notlwen heated, there 
-did not a|)peaf any Abberation/ unlnss tfaak tjbe jmiduQtion of 
jmlphtti^ite gas. was. mmh diminished. Tht aietnUio wm tiiwi 
placed in a sand-bath moderately warm, by which, more of the 

aidph»Kdi« gas wa$ Obtained, bnt lim iStm aoi^n jbcgan to 
ottoe; : After the la#se <)jf ttya tJtfeer idayg,1 addeid f3r#dmlly 
alx ounces of tiAA wMer ^>y which Ihc liqwd ^m chasged to 
reddish-brownu a iconisid^r^Je mf^^vi of the ssi»& fsolour 

subsided, the odour of sulphureous gas,iif}]9$h i^.some iasteaawe 

jbadiStiU frevaited, was jsom^iitely an»illed, Jiad ^fts isuc- 

ceeded l»y otoe iVbicfh pes(^itiji»l$4 » loi^ute ^sikf£ iawtidfer 
and peppermint. 

The whole was then subjected to gradual distillation,, 

during which, the water came over strongly impregnated with 

the odour abovementioned, accompanied by a yellowish oil 



304 Mr. Hatchett's additional Experiments 

which floated on the top of it, aiid which, as far as could be 
ascertained, amounted to about three grains. 

B. When the whole of the water was come over, there was 
again a slight production of sulphureous gas. I then added 
two ounces of water, which I drew off by distillation, but did 
not obtain any of the vegetable essential oil which has been 
mentioned, nor did the odour of it return, I therefore conti- 
nued the distillation until a dry blackish brown mass remained ; 
this was well washed with warm distilled water, by which, 
however, nothing was extracted ; but when two ounces of 
alcohol were digested on it during twenty-four hours, a very 
dark brown tincture was formed. 

The residuum was digested with two other ounces of alcohol 
in like manner, and the process was repeated until the alcohol 
ceased to act 

The residuum had now the appearance of a compact sort of 
coal in small fragments, it was then well dried, and after ex- 
posure to a low red heat in a close vessel weighed fifty-three 
grains. 

C. The different portions of the solution formed by alcohol 
were added together, and being distilled by means of a water* 
bath, a blackish brown substance was obtained, which had the 
appearance of a resin or gum with a slight odour of caromel, 
and weighed 49 grains. 

The products therefore which were thus obtained from 100 
grains of camphor when treated with sulphuric add, were. 



on a Substanoe possessing the Prop^es /fTuinin. $os 

Grains. 

A. An essential .oil which had an odour somewhat rer 

' •• ... . . , 

sembling a mixture of lavender and peppermint, about - 3 . 

B. A compact and very hard sort of coal in small 
fragments - - - - - gg 

C. And a blackish brown substance of a resinous 
appearance - - - -., 49 



105 



From this statement. it appears, that there .^vas an increase in 
the weight amounting.to five grains, which I attribute partly to 
oxygen united to the carbon, and partly to a portion of water so 
intimately combined with the. last product, that it could not b^ 
^xpell^d fromat by heat without subjecting it to decompositipn. 
The properties of this substance were as follows : 

1. It was extremely brittle, had somewhat of the odour of 
caromel, the flavour was astringent, and it speedily dissolved 
in cold water, and formed with it a permanent dark brown 
soluticMi. 

2. This solution yielded very dark Inrown precipitates by the 
addition of sulphate of iron, acetite of lead, muriate of tin, and 
nitrate of lime. 

3. Gold was copiously precipitated by it from its solution in 
the metallic state ; and 

4. By solution of isinglass, the whole was completely preci- 
pitated, so that after three or four hours, a colourless water 
only remained. 

The precipitate was nearly black, and was insoluble in boiling 
water ; from which property, as well as from the effect pro- 
duced upon prepared skin by the solution, it was evident, that 
the substance thus obtained from camphor, was a variety of 

MDCccv. R r 



So6 Mr. HATCHfiTt's additional Experiments 

the artificial tanning matter, much resembling that which may 
be obtained from resinous bodies by means of sulphuric acid. 
But it must be observed, that this sort of tanning substance 
sbems to act less powerfully on skin, than that which is pre- 
pared from carbonaceous substances by nitric acid, and the 
precipitate which the former produces with solution of gelatine 
is ^nore flocculent and less tenacious, than that which in like 
maimer is formed by the latter. 

It is however remarkable, that wheh' a small quantity of 
nitric add vras added to the solution oFthfe substance obtained 
from camphor, and When after evaporating it to drjmess, the 
Residuum Was dissolved in water, a reddish brovm liquM was 
formed, which acted ih every respect similar to the tanning 
substance obtained from the Varieties of coal by nitric acid. 



§vn. 

From the experiments which have been related, it appears, 
that thtee varieties of the artificial tanning substance may be 
formed, viz. 

ist. That which is produced by the action of nitric acid upon 
any darboiiaceous substance, whether vegetable, animal, or 
mineral. 

Sdly. Hiat, wbich is formed by ^stilling nitric add from 
c&mmon resin, indigo, dragon's blood, and various other sub^ 
stances; and, 

gdly. That'^ich is yielded to alcohol by common resin, 
ektol, asa fcBtida, camphor, &c. after these bodies have been 
for some time previously digested "Vvith sulphuric acid. 

Upon these three products tis^aH now make a few remarks. 



Qn a Substance posses&t^ the Proper^m i^Tannin* 307 

which I have hitherto postponed, in order that the account of 
the experiments might not be interrupted. 

The first variety is that which is the most easily formed ; and 
from some experiments which were purposely made, I find 
that 100 grains of dry vegetable charcoal. af&>rd 1 20 of the tan- 
ning substance ; but as it is extremely difficuk completely to 
expel moisture, or even the whole of the nitric acid which has 
been employed,^ an allowance of about three or foiur grains 
ought to be made, so that after this deducticm we may conclude^ 
that 100 grains of vegetable charcoal yield 116 or 117 of the 
dry tanning substance. 

The proportions of the constituent parts of this substance I 
have not as yet ascertained ; but from the manner by which it 
is produced, carbon \b evidently the base of it, and is the pre^ 
dominating essential ingredient 

From § III. experiment F. it also appears, that the other 
component parts are oxygen, hydrogen, and nitrogen ; for 
when the artificial tmning substance was distilled, ammonia and 
carbonic acid were obtained, exclusive of a very small portion 
of a yellow liquor, which stained the upper part of the retort, 
imd which, from its tenacity and insolubility in water and 
alcohol, appeared to be of an oily nature. 

As i had taken every precaution respecting the charcoal 
which had been employed, I was at first induced to consider 
the above facts as almost positively demonstrative of the pre- 
sence of hydrogen in charcoal, but upon farther reflexion, and 
upon weighing some of the circumstances which attend the 

* The most effectual method of expelling the nitric acid, is to reduce the tanning 
substance to powdf^r, and repeatedly evaporate different portions of distilled water 
from it io a glass or porcdtin basin* 

Rr s 



308 Mr. Hatchett's additional Experiments 

formation of the artificial tanning substance, I still feel on this 
point very considerable doubt; fori have constantly observed, 
that diluted nitric acid, acts upon charcoal more effectually, in 
the formation of the tanning substance, than when it is em- 
ployed in a concentrated state; and it appears therefore very 
probable, that hydrogen may have been afforded by a portion 
of water decomposed during the process. For admitting that 
the new compound (formed by the action of nitric acid 
upon charcoal ) may possess a certain degree of affinity for 
hydrogen, this being exerted simultaneously with the affi- 
nity for oxygen possessed by nitrous gas, may (especially 
when the last is in a hascent state ) effect a decomposition of a 
portion of water, the hydrogen of wTiich would therefore enter 
into the composition of the tanning substance^ whilst the oxygen 
would supply the place of part of that which had been taken 
from the nitric acid. 

Many of the properties of the tanning substance prepared 
from coal by nitric add are very remarkable, particularly 
those which have been noticed in § III. experiments F. and G. ; 
for surely it is not a little singular, that this substance when 
^ burned should emit an odour so very similar to animal matter, 
notwithstanding that the tanning substance had been prepared 
from pure vegetable charcoal. And again in experiment G. 
the portion which had not been precipitated by solution of isin- 
glass, was, when dried, found to possess a strong vegetable 
odour very analogous to oak bark, although charcoal is inodor^ 
ous, and isinglass very nearly so. 

But, after all, the most extraordinary properties of this sub- 
stance are certainly those which so nearly approach it to the 
vegetable principle called tannin; for it perfectly resemUes 






on a Substance possessing the Properties o/* Tannin. 309 

this principle by its solubility in water and in alcohol, by its 
action upon gelatine and upon skin, by the effects which it 
produces upon metallic solutions, upon those of the earths, and 
of the alkalis. 

The sulphuric and muriatic acids also affect the solutions of it 
as they do those of tannin ; and the only marked difference 
which as yet has been found in the characters of the artificial 
substance ^ndoi tannin, is yXhzt the former is produced, whilst the 
varieties of the latter are more or less destroyed by nitric acid. 
This, for the present at leasts must draw a line of separation 
between them, but we must not forget, that even the varieties of 
tannin * do not accord in the degree of destructibility. 

• I shall here venture to state some ideas which have occurred to me on the probable 
cause and mode of the formation of tannin, 

Mr. Biggin has proved^ that similar barks when taken from trees at different 
seasons, differ as to the quantities of tannin contained in them. (Phil. Trans. 1799; 
p. 259.) 

Mr. Davt also observes, *' that the proportions of the astringent principles in barks 
vary considerably according as their age and size are different.** 

" That in every astringent bark the interior white bark (which is the part next to 
the alburnum) contains the largest quantity of tannin. The proportion of extractive 
matter is generally greatest in the middle or coloured part ; but the epidermis seldom 
furnishes either tannin or extractive matter." 

Moreover Mr. Davy remarks ** that the white cortical layers are comparatively 
most abundant in young trees, and hence their barks contain in the same weight a 
larger proportion of tannin than the barks of old trees." Phil. Trans. 1803, p. 264. 

We find, therefore, 

I St. That the proportion of tannin in, the same trees is different at different seasons'. 

2dly. That tannin is principally contained in the white cortical layers, or interior 
white bark which is next to the alburnum or new wood : and 

3dly. That these white cortical layers are comparatively most abundant in young 
trees, and that their barks consequently contain in the same weight more tannin thai\ 
the barks of old trees. 

I shall not make any remarks on the first of these facts, as it accords with other 
similar effects, which are the natural consequences of the processes and periods of vege^ 



310 Mr. Hatchett's additional Experiments 

The second variety of the tanning substance is obtamed from 
a great number of vegetable bodies, such as indigo, dragon's 
blood, common resin, &c. &c. by digesting and distilling them 
with nitric acid. It is not, therefore, quite so readily prepared 
as that which was first described, and its relative quantity, when 
compared with that of the substance employed to produce it, is 
less. 

As resin and some of the other bodies do not a&)rd it until 
they have been repeatedly treated with nitric acid, and as dur- 
ing each operation nitrous gas is produced, whilst the strength 
of the acid which comes over is diminished, it seems almost 

tation ; but the second and third appear to be important ; for they prove that tannia 
is principally formed, or at least deposited, in the interior white bark« which is next to 
the alburnum or new wood ; so that in the very same part where the successiiw portions 
of new wood are to be elaborated and deposited, we find the principal portion of 
tannin. 

It should seem, therefore, that there is an intimate connexion between the forma* 
tion of new wood and the formation of tannin in such vegetables as afford the 
latter; and this idea is corroborated when the chemical nature of these substances is 
considered. 

From experiments nlkde on the ligneous substance of vegetables, or the woody fibre^ 
it appears to be composed of carbon, oxygen, hydrogen, and nitrogen, but of these its 
principal and essential ingredient is carbon. 

In like manner carbon is unquestionably the basis and principal ingredient of tannin. 
Considering, therefore, that both of these substances consist principally of carbon, 
that tannin is secreted in that part of barks where the formation and deposition of new 
wood take place, and that the quantity of tannin is the most considerable in yoimg 
trees;* and seems therefore to keep pace with their more vigorous growth and consequent 
rapid formation of wood, it appears very probable that those vegetables which contain 
tannin, have the faculty of absorbing more carbon and of the other principles than 
are immediately required in the formation of the di£Ferent proximate vegetable sab- 
stances, especially the woody fibre : that this excess, by chemical combination^ 
becomes tannin, which is secreted in the white interior bark : that in this state it it 
a principle peculiarly fitted to concur by assimilation to form new wood : that it is 
therefore subsequently decomposed at the proper period, and is employed in the 



on a Suhitance possessing the Properties ^Tannin. 511 

evident, that this tanning substance is formed in consequence of 
part of the oxygen of the nitric acid becoming combined with 
the hydrogen of the original body, so as to form water ; and 
the carbon being thus in some measure denuded, is rendered 
capable of being gradually acted upon by the nitric add in a 
manner nearly similar to that, which takes place when It has 
been previously converted into coal. 

The colour of tile precipitates which this taniiing substance 
yields with gelatine is constantly pale or deep yellow, whilst 
that of the precipitates formed by the first variety is always 
brown ; I am therefore induced to believe, that the different 
oolours of the precipitates produced by the varieties of tannin 
depend on the state of their carbon. 

When resin and the other bodies were treated as above 
described with nitric acid, the quantity obtained of the tanning 
substance was much less dian when an equal quantity of coal 
was employed, or even when these bodies had been previously 
converted into coal in the humid way by sulphuric acid. 

The cause of this seems to be, that a number of other pro- 
ducts are simultaneously formed, all of which require more or 
less of carbon as a constituent ingredient, so that,' in consequence 
of the affinities which prevail under the existing drciimstances, 

formation of the new wood : t)iat there h not a contnmai ftctuaiukliod «f tannin in 
the vegetables which afFofd it, as it is snCctssitely formed in and with the whke eor^^ 
tlcal layers^ and is Successively decomposed by contnrrtng to ferm new wood : and> 
lastly, that as the vegetable approaches itiore nearly tt> the full maturity of Its grawth, . 
when wood is less rapidly and leis plentifully formed, so in like manner less tannin is 
secreted, for the fabric being nearly completed, fewer materials are requit^ed. 

Sucb I am inclined to suspect, from the l^tts whtch have been adduced, to be the 
cause and mode by which tannin is formed in oaki atid other vegetables, but I mak« 
this statement only as a probable conjecture, which may be refuted or confirmed by 
future observations. 



Si» Mr. Hatchett's additional Experiments 

some bodies by treatment with nitric acid afford but little, and 
others none of the tanning substance. 

The greatest proportion of this substance was yielded by 
indigo, common resin, and stick lac. 

The quantity obtained from asa foetida and gum ammoniac 
was less. 

Benzoin, balsam of Tolu, balsam of Peru, and dragon's 
blood, were inferior to the former in this respect, so that the 
developement or rather production of benzoic acid * appeared 
partly to counteract the formation of the tanning substance. 

• The expression " production of benzoic acid** may appear objectionable* and I 
shall therefore take this opportunity to observe, that I much suspect the present esta- 
blished opinion respecting the balsams and benzoic acid to be erroneous. For the 
balsams are defined as bodies composed of resin and benzoic acid ; consequently the 
latter, when obtained in a separate state, is considered as an original ingredient or educt. 

I am however inclined to a contrary opinion, for I consider the balsams as 
peculiar substances, which, although nearly approaching to the nature of resins, are 
nevertheless different in respect to the original combination of thoir elementary prin- 
ciples, which combination however is with much facility modified by various causes, 
and especially by a certain increase of temperature, so that a new arrangement of the 
elementary principles takes place, part being formed into resin^ and part into benzoic 
acid. 

Many facts appear more or less to support this opinion ; for whether benzoic acid is 
obtained by simple sublimation, or by merely digesting benzoin in boiling water, accord- 
ing toGfiOFFROY's method,or by the addition of lime, as recommended by ScHBELB,or 
by employing alkalis in a similar manner, nothing positive can be inferred from any 
of these operations to prove that benzoic acid is obtained as an educt, but rather the 
£ontrary, when we reflect on the affinities which are most likely to prevail under the 
icircumstances of the different processes, and on the variable proportions of the benzoic 
acid ; and although benzoic acid has been discovered ia the urine of infants, in that 
of many adults, and constantly in that of graminivorous quadrupeds, such as the 
camel, the horse, and the cow, {SysUme des Connoissances Cbimigues, par Foua- 
caor, 4to edit. Tome IV. p. 158 ;) yet all this certainly appears to be in favour of its 
being a chemical product. 

J have observed, when benzoin> balsam of Tolu, and balsam of Peru, were dissolved 



on a Sul^Umee poi^ssing the Properties d/* Tannin. 315 

but oxalic add when fonned in any considerable Quantity, 
seemed absolutely to prevent the formation of this substahce; for 
whilst abundance of the former was obtained from gum arable, 
tragacanth) manna^ and guaiacam^ not any of the latter (iould 
be produced. * . 

Common liquorice appears at first to be an exception^ but 
from the smallness of the quanthy and the colour ' of the 
pfedpitate which it produced with solution of isinglass, I Itm 
almost convin^d that the tanning substance was formed by the 
action of the nitric add on a portion of unconibiAed car boh^ 

Ia SQlphimc acid» tkat a great Quantity of b^auBfuUy cryslaUtzed white* bedzdc aCid 
was sublimed during digestion ; ^ud as it is produced in so very p^re a state by this 
single and simple operation, I would ,recommend a trial oif the process to those wha 
prepare benzoic acid for eonnffer^^ btit I am not certain n^hethev this mbde may prove 
more economictti fhaiy th<M wMch at:present ai^e ^filpldydd.> 

Wli^ 4ngpvt*» blodd, b^wttvcr, w«A trealed ifi t^ same manner w.ith sulphuric acid» 
I could not obtain a particle of benzoic acid ; nor did I succeed much better when I had 
recourse to lime> according to Schrblb's process ; for although a considerable quantify 
of the substance w^s thiis-V^nden^d sbiubfe fn water, y^ by the addition of mu/iatic 
iiAA I obtamrd odly a'stigbt app^mnce of benzoic acid accovnpaniM by a copious 
precipitate of rt^ resin, notwithstanding that the solution had acquired a powerful 
and peculiar balsamic odour. 

But in a former part of thh Paper I have stated, that tvhWi dragon's blood was 
dhselved lo riitpic- slcid> and afterwards evaiporafed tordryndstf, it yielded about 6 p€r 
cent, of benzoic acid. Now if this had been originally present in dragon *s blood in the 
state of benzcHC acid, some stronger evidence of it might reasonably have been ex- 
pected in each process, bat this not being the case, I am inclined to consider it as pro* 
daced, and not educed, by the action of the nitric achl^oii the original principles of the 
dragon's h\aoA ; ani I am alsfar penuadrd that sinilay but more gisnel-al edects take 
place whefv benzoin, or any of tl4e balsams are subjected to' the different processes by 
which benzoic acid is obtained ; so that to .me, this last seems to be as much a chemical 
product, as the oxalic, the acetous, and other of the vegetable acids. 

The succinic acid also appears to be a produdf and iK>r an original ingredient of 
*aaibor« 

MDCCCV. S S 



SI 4 ^/- Hatchett's additional Experimnis 

which being in'a state approaching to'coal, is* probably the 
cause of the blackness of the common liquorice. 

< As the formation of the tanning substance has been my prin- 
cipal object, I have not thought it necessary to enter at present 
into too minute a detail of other particulars, and have therefore 
only thus cursorily noticed some of the prindpal effects pro- 
duced by nitric acid on the resins, balsams, &c. Those however 
who are conversant with chemistry, will undoubtedly perfceive 
that these effects deserve to be accurately investigated, and that 
the resins, balsams, gum rfisins, and gifans, shoiild be Regularly 
examined by every possible method, not merely on account of 
the indii^idiial substances which may become the subjects of 
experiment, but because' there is reaston to expect that from 
such an investigation, medicine, with the arts, and manufactures, 
may derive many advantages, whilst the mysterious processes 

and effects of vegetation may very probably receive ^consi- 

' ^ ' '- ' ' ' ± ' * < > * 

derable elucidation. ... 

• - • . » . ^ ' . .. .-. 

Concerning the^hird variety of the .tanning substance, which 
is produced by the action of sulphuric acid on the resins, gima 
resins, &c. I shall here add but little to that which I have 
already stated in the latter part of the second section of my 
first paper, and in the account which I have lately ^ven of 
an experiment on camphor. 

This variety appears to be uniformly produced during a 
certain period of the process^ but by a long continuance of the 
digestion, I have reason to believe that it is destroyed. 

Substances, such as the gums, which afford much oxalic 
acid by treatment with other acids, do not apparently yield any 
of this tanning substance. 

The energy of its action on gelatine and skin is certainly 



on a Substance possessing the Properties of Tannin. 315 

inferior to that of the first variety, into which however ( as we 
have seen ) it may easily be converted by nitric acid. 

From the mode of its formation, there does not appear 
to be any positive evidence that it contains nitrogen like the 
first and second varieties, and perhaps the absence of nijtro- 
gen may be the cause of its less powerful action ; this I have 
not as yet ascertained, but it is my intention more particularly 
to notice in a future Paper the general properties of this 
substance. 



{ 
/ 



Ss 3 



C«»6 3 



XXII. On the Discovery of Palladium ; with Obwvations on 
other Substances found with Platina. By WilUatyi Hyde 
Wollaston, M.D, Sec. tl.S^ 



JlIaving some time since purified a large quantity of platina 
by precipitation, I have had an opportunity of observing various 
drcumstances in the solution of this singular mineral, that have 
not been noticed by others, and which, I think, cannot fail to 
be interesting to this Society. 

As I have already given an account of one product obtamed 
from that ore,which I considered as a new metallic substance, and 
denominated Rhodium, I shall on the present occasion confine 
myself principally to those processes by which I originally 
detected, and subsequently obtained another metal, to which I 
gave the name of Palladium^ from the planet that had been 
discovered nearly at the same time by Dr. Olbers. 

In the course of my inquiries I have also examined the many 
impurities that are usually mixed with the grains of platina, but 
I shall not think it necessary to describe minutely substances 
which have already been fully examined by others. 

§ L Ore of Iridium. 

1 must however notice one ore, that I find accompanies the 

ore of platina, but has passed unobserved from its great re- 

jsemblance to the grains of platina^^ and on that account is 



Dr. WoLLASTON on the Discovery of Palladium. 517 

scarcely to be distinguished or separated from them, excepting 
by solution of the platina ; for the grains of which I speak ard 
wholly insoluble in nitro-muriatic acid. When tried by the file, 
they are harder than the grains of platina ; under the hammer 
they are not in the least degree malleable ; and in the fracture 
they appear to consist of laminae possessing a peculiar lustre ; 
so that although the greater number of them cannot, as I have 
before observed, be distinguished from the grains of platina, 
the laminated structure sometimes occasions an external form 
by wliich they may be detected. With a view to be absolutely 
certain that there exist grains in a natural state, which have 
not been detached by solution from the substance of the grains 
of platina, I have separated from the mixed ore as many aa 
enabled me to ascertain their general compositicMti. 

Their most remarkable quality is their great specific gravity, 
which I have found to be as much as i>$,5, while that of the 
crude grains of platina has not, in any experiment that I have 
made, exceeded 1 7 ,7 . From this circumstance it might naturally 
be ODHJectured that tliey conifcain a greater quantity of platina 
than the grains m general ; by ana-lysis,; hbwever,^ they do not 
appear to me to contain^ the smaJlest quantity of that metalybut* 
to-be an ore cousistiag emiTely of the metal* ti>all were found 
by Mr. Ten n ant in the black powder, which is extricated by 
9olutro£v fkoixi the g^jains of platma, arid which he has called 
Iridiwp and OBmiun. B\xt^ siaee tte specific gsravity of thes^ 
ffwna so nweb exceeds^ that of the! ^ wdler,. which by my ex*^ 
periments has appeared to be, at the utmost, J4L,si, I have 
tiK>ught it. wight desevve 'mtfimy whether their cliemical €!6m-* 
pMitk)Ck i& m- any mspect differeiMy. For this purpose I have 
selected a portion of them, and have* iseqiiested Mr. Tbknant 



31 8 Dr. WoLLASTON on the Discovefy of Palladium. 

to undertake a comparative examination, from whose well 
known skill in chemical inquiries, as well as peculiar knowledge 
of the subject, we have every reason to expect a compkte ana- 
lysis of this ore, 

§ II. Hyacinths. 

Among those bodies which may be separated from the ore 
of platina, in consequence of their less specific gravity, by a 
current of water or of air, there may be discerned a small 
proportion of red crystals so minute, that lOo of the largest I 
could collect weighed scarcely ^ of a grain. The quantity 
which I poissess is consequently too small for chemical analysis ; 
but their physical properties are such as coirespond in every 
respect with those of the hyacinth. I was first led to compare 
them with that stone by their specific gravity, which I con- 
jectured to be considerable from their accompanying other 
substances, that appear to have been collected together solely 
by reason of their superior weight. 

Like the hyacinth, these crystals lose their colour imme- 
diately and entirely when heated ; they also agree with it in 
their hardness, which is barely sufficient to scratch quartz, but 
is decidedly inferior to that of the topaz. 

The principal varieties of their form may be very well un- 
derstood by description. 

ist. In its most simple state the crystal may be considered 
as a rectangular prism terminated by a quadrilateral obtuse 
pyramid, the sides of which sometimes arise direct from the 
sides of the prism ; but, 

sdly. The position of the pyramid is generally such that its 
sides arise from the angles of the prism. In this case the sides 
of the prism are hexagons. 



•. WoLLASTON on the Discovery of Palladium: 319 

gdly. It is more usrual for the prism to have eight sides by 
truncation of each of its angles, and at each extremity eight 
additional surfaces occupying the place of the eight linear 
angles between the prism and terminating pyramid of the 2d 
variety. The complete crystal has then thirty-two sides. 

4thly. The eight surfaces last mentioned, as interposed 
between the prism and pyramid, are sometimes elongated into 
a complete acute pyramid having eight sides arising from the 
angles of an octahedral prism. 

The 3d form above described, corresponds so entirely with 
that given by the Abbe Hauy * as one of the forms of the 
hyacinth or jargon, that I have little reason to regret my inabi- 
'lity to obtain chemical evidence of the composition of these 
crystals. 

Those^ and other impurities, I usually separated, as far as 
was practicable, by medianical means, previously to forming 
the solution of platina, which has been the principal object of 
iiiy attention. 

§ III. Precipitation of Platina. 

When a considerable quantity of the ore had been dissolved, 
and I had obtained, in the form of a yellow triple salt, as much 
of the platina as could be precipitated by sal anmioniac, clean 
bars of iron were next immersed in the solution for the purpose 
of precipitating the remainder of the platina. 

For distinction it will be convenient to call this, which in fact 
.consists of various metals, the first metallic precipitate. 

The treatment of this precipitate differed in no respect from 
that of the original ore. It was dissolved as before, and a portion 

• TraiU d$ Mineralogie, PI. XLL £g. ij^r^Jonrn. dis Mines, No. 26^ fig. 9* 



jf I>. WoLLASTON OH the Dtscowfy of Palladium. 

of platina precipitated by sal ammoniac ; but it was observable 
that the precipitate now obtained was not of so pale a yellow as 
the preceding. Nevertheless the impurity was in so small quan-« 
tity, that the platina reduced from it by heat did not diiier 
discemibly from that obtained from the purest yellow preci- 
pitate. 

At this time I found it advantageous to neutralize the solution 
with soda, and to employ a solution of green sulphate of iron 
for the precipitation of the gold, of which, I believe, a portion 
may always be obtained from the mixed ore ; but I have ob- 
served in experiments upon any quantities of mere grains of 
crude platina carefully selected, that the smallest portion of 
gold could not be detected as a constituent part of the ore 
itself. 

Bars of iron were subsequently employed as before for re- 
covering the platina that remained dissolved, together with 
those substances which I have since fotmd to accompany it. 

The precipitate thus obtained, which I distinguish by the 
name of the second metallic precipitate, was to appearance of 
a blacker colour than the former, and was a finer powder. 

As f was not at first prepared to expect any new bodies, I 
proceeded to treat the second precipitate, as the former, by so- 
lution and precipitation. But I soon observed appearances 
which I could not explain by supposition of the presence of any 
known bodies, and was led to form conjectures of future disco- 
veries, which subsequent inquiry has fliUy confirmed. 

When I attempted to dissolve this second metallic preci|Mtate 
in nitro-muriatrc acid, I was surprised to find that a part of it 
resisted the action of that solvent, notwithstanding any varia- 
tions in the relative proportions or strength of Ae acids 



Dr. WoLLASTON on the Discovery of Palladium. gar. 

employed to form the compound, and although the whole of this 
powder had certainly been twice completely dissolved. 

The solution formed in this case was of a peculiarly dark 
colour, and when I endeavoured to precipitate the platina from 
it by sal ammoniac, the precipitate obtained was small in quan- 
tity, and, instead of being yellow, was of a deep red colour, 
arising from an impurity which I did not at that time understand, 
hut which we since know, from the experiments of Mr. Des- 
coras, is occasioned by the metal now called iridium. 

The solution, instead of being rendered pale by the precipita-, 
tion of the platina, retained its dark colour in consequence of 
the other metals that remained in solution ; but, as I had not 
then learned the means of separating them from each other, 
and as the quantity of fluid which accumulated occasioned me 
some inconvenience, I decomposed it by iron, as in the former 
instances, and formed a third metallic precipitate, which could 
more commpdipusly be reserved for subsequent examination. 

In this last step L committed an error which afterwards occa- 
si<med me considerable difRculty, for I found that a great part 
of this precipitate consisting of rhodium was unexpectedly ren- 
dered insoluble by this treatment, and resembled the residuum 
Qf the second metallic precipitate abovementioned. 

As I have already communicated to this society, in my Paper 
upon rhodium, the process by which I subsequently avoided 
this dilficulty, I shall at present return to a previous stage of 
my progress, and relate the means by which I first obtained 
palladium in my attempts to analyze the second metallic pre- 
cipitate. 



MDCCCV. T t 



09« JS>r. W01.X4A8TQN m the IXscmfepy: iff PqUvHum^ 



There was no difficulty in ascertaining the presence of lead 
as one of the ingredients of this precipitate, by means of mu- 
riatic acid, which dissolved lead and iron and a small quantity 
of copper. It was equally easy to obtain a larger portion of* 
copper by dilute nitrous acid, with which it formed as usual a 
blue solution. But when I endeavoured to extract the whole 
of the copper by a stronger acid, it was evident, flrora the dark^ 
brown colour of the solution, that some other metallic ingre- 
dient had also been dissolved. I at first ascribed thi? colour 
to iron ; but, when I considered that tMs substance had been 
more slowly acted upon than copper, I relinquished that hy- 
pothesis, and endeavouring to precipitate a portioai of it by a 
clean plate of copper, I obtained a black powder adhering to a 
surface of platina on which I had placed the solution. As- 
this preci^t^te was soluble in nitric add, it evidently ewisiste* 
neither of gold nor platina ; as the solution in that add was of 
a red colour, the metal could not be either silver or mercury ; 
and as Ae predpitation of it by copper excluded the supposi- 
tion of all other known metafe, I had reason^ to suspect the 
presence of some new body, but- was^ not- fully sadsfied' 
of its existence until i attempted the ^edpitatk>n of it by 
mercury. 

For this purpose I agitated a small quantity oF merewy^ in 
the nitrous solution previously warmed, and observed ^ mer- 
cury to acquire the consistence of an amalgam. After thia 
amalgam had been exposed to a red heat, there remained a 
white metal, which could not be fused before the blow pipe. It 
gave a red solution as before^ in nitrous add ; it was not 



V 



Or. W«LLA1ltOir ^ike tksc^vefy ^P^iadium. 3«3 



^VtS^xVAoA ^ ^ik\ ^Rtimotiiab, ^r t>y i»tt*e ; bat by prugfifiate of 
i^iash it gave n yeife w oT<ir}tp^% predpitate; and ifi the order 
«f Its atihiilieslt was ^l^etif^ted by misfsxsry bat i^iot by sitvw. 

Th^se ikft l3ie prdp^^ea l>y which I originalty distingui^lied 
^tladhun ; ^id hj t^ assistance of tiiese jMroperties I obtained 
a aaffident ^quantity for investigating its nature more fully. 

Tlicfre were, however, various reasons which indiiced me to 
««e%hqin&^ fhe eriginal process of solution ki nitrous acid and 
precipitatidn by meroury ; for although I found the metal thus 
obtained to be nearly pure, the necessity otf a^tating die solu- 
tSoft wiA the mercury was very tedious, and the waste was also 
considerable^ for 4n the first place it seemed that nitrous add 
wouM 4fiot extract all the palladium from any quantity of the 
second metallic precipitate, neither would mercury reduce the 
whole of what was so dissolved. I therefore substituted a 
process dependent on another of its properties. I had observed 
diat this metal (fifiered from platina in not %eing precipitated 
from fiitt*o*49iuriatic acid by nitre ^fr by other salts containing 
potash ; for alt^ogh a triple salt is thus formed, this salt is 
extremely solu)>le, while ifeat of patina on the contrary re- 
^i«s a large quantity of water for its solution. On that 
acGounft ^ GoMipotiAid menstruum consistmg of nitrate of potash 
disserved in muriatic acsd is unfit for the solution of platlna, 
but ^ssolves palladium nearly as well as common nkro-mu- 
riatic add in wliich t^iere is no potash present.^ 

bi ^ ve ounces of muriatic acid diluted with an equal quantity 
of water, I dissolved one ounce of nitre, and form^ a solvent 



* I have found that fold may 2iso be dissolved with equal facility by the same 
solvent, and nearly in the same proportion. Ten grains of nitre added to a proper 
quantity of muriatic acid asf wifliMBt for siarteea grains of either gold or palladium. 

Tta 



Sa45 Dr. WoLLASTON on the Discovery of Palladium. 

for palladium that possesses little power of acting <m platkia, 
so that by digesting any quantity of the second metallic preci- 
pitate till there appeared to be no farther action, I procured 
a solution from which by due evKpor;ati<Hi were formed cjrystals 
of a triple salt, consisting of palladium combine^ wUh muriatic 
acid and potash. These are the crystals which I have on a 
former occasion * mentioned as exhibiting a very singular 
contrast of colours, being bright green when si^en traUBveapsely, 
but red in the direction of their axis ; the >ge£ieral a^pept, 
however, of large crystals is dark brown. 

From the salt thus formed and purified by a second crys- 
tallization, the metal may be precipitated /nearly ppre by iron 
or by zinc, or it may be rendered so by subsequent digestion 
in muriatic add. 

§ V. Reasons for thinking Palladium a simple Metal. 

From the consideration of this salt alone I thought it highly 
probable that the substance combined in it with murate of 
potash was a simple metal, for I know of no instfinee in -chemistry 
of a distinctly crystallized salt containing mor^ than two bases 
combined with one acid. I nevertheless endeavoured jby a suit- 
able course of experiments to obviate all probable .objections. 
After examining by what acids it might be dissolved and by 
what reagents it might be precipitated, I combined it with 
various metals, with platina, with gold, with silver, with 
copper, and with lead ; and when I had recovered it from its 
alloys so formed, I ascertained that, after every mode of trial 
it still retained its characteristic properties, being soluble in 
nitrous acid, and precipitable from thence by mercury, by green 

* Phil. Trans. 1804, p. 428. 



. Dr. WoLLASTON on the Discovery of Palladium. 325 

, milphate of iron, by muriate of tin, by prussiate of potash, by 
each of the pure alkalis, and by hydrosulphurets. 

The predpitate obtained in each case was also found to be 

•reducible by mere heat to a white metal, that, except in very 

. small quantities, could not be fused alone by the blowpipe, but 

obuld very readily be fused with sulphur, with arsenic, or 

with phosphorus, and in all other respects resembled the 

original metal. 

The only hypothesis, on which I thought it possible that I 
could be deceived, arose from the recollection of the error, 
which subsisted for a few years, respecting the compound 
formerly called siderite. It was possible that some metallic or 
other fixed acid might unite too intimately with either a known 
or an unknown metal to be separated by the more common 
simple affinities. I consequently made such attempts as ap- 
; peared best calculated to disunite a compound so constituted. 

Having boiled the oxide with pure alkalis, and found it to be 
unaltered, I thought the affinities of lime or lead might be 
• more likely to detect the presence of the phosphoric or of any 
known metallic add ; and accordingly I made various attempts 
by muriate and nitrate of lime, as well as by nitrate of lead, to 
effect a decomposition of the supposed compound. In the ex>- 
periment on which I placed the greatest reliance, I poured 
liquid muriate of lime into a solution of palladium in nitn>- 
muriatic add, and evaporated the mixture to dryness, intending 
thereby to expel any excess of add that might have been left 
in the solution, and to render either phosphate of lime, or any 
compound of lime >vith a metallic acid, insoluble in water. The 
residuum however was very readily dissolved by water, antf 



3«S JDr. WoLLASTON m the Diseavery of Palladium. 

consisted merely of muriate of lime and muriate oT pelkfiKum, 
Without any appearance of decomposition. 

' When I found all my ^endeavours directed to that ^nd wholly 
unsuccessful, I no longer entertained any doubt of this sub- 
stance being a new simple metal, and accordingly published a 
concise delineation of its character ; but by not directii^ iiiQ 
attention of chemists to the substance from which it had iieen 
extracted, I reserved to myself an opportunity of esuunming 
more at leisure many anomalous phenomena, that had occurred 
to me in the analysis of platina, which I was at a loss to explain, 
imtil I had learned to distinguish those peculiarifies^ tJialt I 
afterwards found to arise from the presisnce of rhodium. 

§ VL Additional Properties of Palladium. 

In my former Paper on that subject I also ^ded some ob- 
servations upon the properties and origin ofpalladaira,desaribai^ 
only such a mode of obtaining it from f^ina as should avoid 
llie introduction of any unnecessary ingredient whidi m^ht 
possibly be misinterpreted, and omitted one of the most dis- 
tinguishing properties of paUadium, by means -of which it may 
be obtained with the utmost facility by any one who possesses 
a sufiBcient quantity of tlie ore of platina. 

To a solution of trude platina,. whether rendered neutral hy 
^eitfiaporation of redundant acid, or saturated by addition of 
jx>tash,'df soda, or ammonia, by lime^or magnesia, by men^iiy, 
Jby copper, or by iron, and also whether the pladna has or has 
not been precipitated from the solution by sal ammoniac^ it is 
merely necessary to add a solution of pmssiate of mercury, iouc 
i^pRexapitaftion of the palladium. Oenwallyliorafewseooiids, 



Dr. WozxASTow on iJk Wsccmery (f Ptdladiunh ^^^ 

and sometimea for a few mimites^ there will be m> appearance^ 
of any jNrecipitate ; bitt in a short time tte whole aolutapni be^ 
ooHies. sligl^ turbid^ and a flboculent i»'epipitate ib graduaUy 
femned, of a pafe yellowisK-white colour;. Tlv» precipits^ter 
consists^ wholly of prussiate of paUadium^ and when heated 
will be found to yield that metal m a pure, state., «aiountin^ 
ta about .4 or 5 tenths per ceat. upoa die quantity; oC ore 
dissolved. 

The prussiate of mercury is peculiarly^ adapted ta tbe^ pne- 
capitation of' palhcKum, exclusive of all oAer metals, on afccount 
of tile gpeat affinity of mercury for the pmssic acid, whif^ iir 
tikis, case pvev^its. the precipitation of iron or copp^ ; but thft 
pr4>portion o^ mercury dbes not by any means influence thft. 
quMMqfty of palladium, for I have in vain endeavoured; m: 
the above- experiment on crude platina, tQ^ obtain a largeir 
quantity of palladium than I have stated by using more of thei^ 
pniesiate of mercury, or to procure any precipitate by the: saiQlst 
means £rom a solution of pune platina. 

The decomposition of muriate of palladium; by pniasiate of 
mercuxy is not efi^cted solely by the superieir affinity of mfiX-- 
CHry fbr; the; muriiEitic acid, but is assisted also by ^ greaj^ 
ailnity- of pmssic aqid ton palladfurn; for I have found that 
prussiate of palladium may be formed by boiBng* a parec^piiliit^ 
oxide of pi^Uadium in. a solution of prussiate of m^reury^ 

The prussiate of mercury is consequently a test by whicli; 
the presence of palladium may be detected in any of its solu- 
tions; but it may be worth observing^, that the precipi$a$« 
obtained has not in all cases the same properties. In geqeraji^ 
this compound is aflfected by heat nmilarly to other prussxates^ 
but wh^n^ the palladium has been dissd^ed innil^oua a<ffd:9Bdi^. 



3«8 Dr. WoLLASTON on the Discovery of Palladium. 

precipitated from a neutral solution by prussiate of mercury, . 
the precipitate thus formed has the property of detonating 
when heated. The noise is similar to that occasioned by firing 
an equal quantity of gunpowder, and accordingly the explo- . 
sion is attended with no marks of violence unless occasioned . 
by close confinement. The heat requisite for this purpose lis 
barely sufficient to melt bismuth, consequently is about 500"" of 
Fahrenheit. The light produced is proportionally feeble, and 
can only be seen in the absence of all other light. 

In endeavouring to dissolve a piece of palladium in strong 
colourless nitric acid for the purpose of forming the detonating 
prussiate, I found that, although the acid shortly acquired a red : 
colour surrounding the metal, the action of the acid was ex- 
tremely slow, and I was surprised to observe a fact that appears 
to me wholly singular : the metal was taken up without any 
extrication of nitrous gas ; and this seemed to be the cause of 
the slow solution of this metal, as there was not that circula- 
tion of the fluid, which takes place in the solution of other 
metals until the add is nearly saturated. 

As the want of production of gas appeared to retard the solu- 
tion of palladium, I tried the effect of impregnating a quantity 
of the same acid previously with nitrous gas, and observed its 
action to be very considerably augmented, although the expe- 
riment was necessarily tried in the cold, because the gas would 
have been expelled by the application of heat. 

Beside those properties which are peculiar to palladium there • 
are others, not less remarkable, which it possesses in common . 
with platina. I have on a former occasion mentioned that these 
metals resemble each other in destroying the colour of a large 
quantity of gold. Their resemblance, however, in other. 



Dr. VfoLLAktOi^ on ^Discovery of Palladium. 329 

properties is not leSs' reniarkable, morfe e^pfecially in the little 
power they possess of <x>nductiiig heat, and in the small degree 
of expansion to which they are liable when heated. 
•. I For the ptrrpose of nutking a comparison of the conducting 
powers of different matalfe, I endeavoured, to employ them in 
such a nianner, that the same weight of each metal might ex- 
pose the same extent of surface. With that view I selected 
pieces of silver, of copper, of palladium, and platina, which had 
been laminated so thin as to weigh each 10 grains to the square 
inch. Of these I cut slips -^ of an inch in breadth, and four 
inches long ; and having covered their surfaces with wax, I 
heated one extremity so as to be visibly red, and, observing 
the distance to which the wax was melted, I found that upon 
the silver it had melted as far as 3:^ inches : upon the copper 2^ 
inches : but upon the palladium and upon the platina only 1 
inch each : a difference sufficient to establish the peculiarity of 
these metals, although the conducting power cannot be said to 
be simply in proportion to those distances. 

In order to form some estimate of the comparative rate of 
expansion of these metals, I rivetted together two thin plates of 
platina and of palladium ; and observing that the compound plate, 
when heated, became concave on the side of the platina, I ascer- 
tained that the expansion of palladium is in some degree the 
greater of the two. By a similar mode of comparison I found 
that palladium expands considerably less than steel by heat ; so 
that if the expansion of platina between the temperatures of 
freezing and boiling water be estimated at 9 parts in 10,000, 
while that of steel is known to be about 12, the expansion of 
palladium will probably not be much more or less than 10, or 
one part in 1000 by the same difference of temperature. 

MDCCCV. U u 



$QO Dr. WolLASTON on the Discovery of Palladium. 

It must, however, be acknowledged that the method I have 
pursued is by no means sufficient for determining the predse 
quantity of expansion of any substance ; but I have not been 
induced to bestow much time on such an inquiry, since the 
extreme scarcity of palladium precludes all chance of any prac- 
tical utility to be derived from a more acx^urate investigation. 



. N .1 



t I 



C m 2 



XIII. Experiments on a Mineral Substance fomterfy supposed Ut 
be Zeolite ; with some Reinafia on two Species of Uran-glimmer. 
By the Rev. William Gi^gor. Omimunicated by Charles 
Hatchett, Esq. F. R. S. 



" Read July 4, 1805; 

Ti « 

H I s mineral is^ paised in a mine called Stenna G wyn, in the 

parish of St. Steyhe^^^ m Bran well, in the county of Cornwall } 

the princip4 jproduQticm of whidi i& the compound sulphuret of 

tin^ copper; .^id iron; 

DescriptiM. 

Two spedes of thrs mineral are fdtirid, assurfiihg a marked 
diflference in external character. 

The first and most common one consists of an assemblage of 
minute crystals, which are attached to quartz crystals, in tufts, 
which diverge from the point of adherence, as from a centre. 
These tufts vary, as to the number of crystals, of which they 
are composed, and are fight and delicate in the forms which 
they assume, or they are grouped together according to a 
variety of degrees of proximity and compactness. Sometimes 
they fill the whole cavity of a stone, with little or no interrup- 
tion ; in other specimens they are seen partially spreading over 
the sides and pointed pyramids of quartz crystals. 

In some cases these grouped tufts adhere very pertinaciously 
to the stone which bears them ; in others, they are easily se- 
parable, in comparatively large pieces, from the quartz, he 

Uua 



33^ A^^'- Gregor's Experintents on a Mineral Substance 

impressed form of which the pieces thus separated, retain. The 
surface of these, which was in immediate contact with the 
qudrtz, exhibits the Sieveral minute crystals of which the masks' 
consists, matted together in various, directions. 
, Th^se crystalline a^sembjgges are, iSx general, white ; a 
nearer inspection of the individual crystals proves that they 
are transparent. Sometimes they are stained of a yellowish 
hue by ochry water. 

The size of these crystals varies considerably in different 
specimens. Sometimes they assume the appearance of a whjite 
powder raised up in small heaps, upon the surface of the stone, 
to which they adhere. In other specimens they resemble a 
tender down. And the larger sort variefs, in relative size, in ^e 
proportion, perhaps, in which a human haii*, horse-hair,. arid a 
hog's bristle, severally differ from each other in magnitude. 
They seldom exceed a quarter of an inch in length. The 
figure of these crystals is not easily ascertainable,, on accoijmt 
of their minuteness. By the help of a very powerful rnicros- 
cope, they appear to consist of four-sided prisins; where these 
are broken off, the section exhibits a rhomboidal, approaching 
indeed to an elliptical figure, from the circumstance of the 
angles of the prism being worn away ; but that the prism itself 
is rhomboidal, cannot be inferred from hence, unless we 
could be certified, that the section were at right angles with 
the axis of it. 

Imbedded amongst these crystals two species of crystalline 
laminae are frequently discoverable : the one consisting of par- 
allelopipedon plates with truncated angles, applied to each 
other, of a green colour of various tints, from the emerald to 
the apple-green : the other species, consisting of an assemblage 



formerly supposed to be Zeolite, &c. 333 

of square plates, which vary in thickness. The angles of the 
several ^uare laminae, which are applied to each other are not 
always coincident. They are of a bright wax yellow. The 
sides^ of the largest of these square laminae is about a quarter 
of an inch. This last species is frequently found adhering to 
the sides of quartz crystals, in the cavities of granite. 

The other species of this mineral consists of an asisemblage 
of crystals closely compacted together in the form of mam- 
millary protuberances, in general, of the size of small peas, 
intimately connected with each other. A stratum of these 
about -|^ of an inch thick is spread upon a layer of quartz, in 
the cavities or fissures of a species of compact granite^ The 
strias of which these mamillse consist diverge from a centre, 
like zeolite. Some of the individual striae, in some cases, over- 
top their fellows, in these globular assemblages, and evidently 
assume, on their projecting points, a crystallized form, 

A. 

( 1 . ) The detached crystals of the former species are easily 
reduced to powder, of a brilliant whiteness. At the temperature 
S,^ of Fahrenheit, its specific gravity was found to be 2,22. » 

( 2. ) The hardness of the more compact species is sufficient 
to scratch calcareous spar. At the temperature ^s"", its specific 
gravity was 2,353. '^ ^^^^ ^^^ imbibe water. 

( 3. ) Some of the crystals exposed, on charcoal, to the flame 
of the blowpipe suddenly and strongly driven upon them, 
decrepitate : if they are gradually exposed to the flame they 
grow opaque, and become more light and tender : but they 
show no signs of fusion under the strongest heat. 

(4.) The phosphate of soda and ammonia takes up a piece 



334 ^^' Gregor's Experiments on a mineral Substance 

of this mineral without effervescence, but it swims about die 
fused globule, unaltered. Borax dissolves a fragment of a 
crystal, and the globule remains transparent. 

( 5. ) Some of this mineral, reduced to a fine powder, was 
mixed with about half its weight of pounded quartz, and kneaded 
with water into a ball : but as aoon as the mass became drj, 
all cohesion was destroyed, and it fell into powder. 

(6.) Sulphuric acid, poured ' upon some of it, caused no 
effervescence, nor was there any perceptible vapour extricated. 

(7. ) Some of the pulverized crystals were put into a crucible 
of platina, and sulphuric acid was poured upon them. The 
crucible was covered with a piece of glass, and placed in warm 
sand. On examination of the crucible and its contents, after 
some time, it appeared that the greater part of the mineral 
had been dissolved, but the surface of the glass cover was not 
in the least afiected. 

( 8. ) Some of the crystals were introduced into a small glass 
retort, to which a receiver was adapted. The retort was ex- 
posiedto the heat of a charcoal fire. A fluid distilled over into 
the receiver, which had a peculiar empyreumatic smell. It 
changed litmus^paper to a faint red. It produced no change 
in a solution of nitrate of silver ; but it caused a white preci- 
pitate in a solution of nitrate of mercury. I attributed these 
phaenomena, at the time, to a small bit of the feather with 
which I had swept the powder into the retort, and which, I 
thought, had fallen into it. A slight whitish crust was also 
produced in the neck of the retort, but the smallness of the 
quantity did not admit of examination. 

(9. ) Some of this mineral exposed to a red heat, for about 
ten minates, lost in weight at the rate of q^^ per cent. Another 



formerly supposed to he Zeolite^ &c. 335 

portion^ exposed to a stronger heat for more than an hour, 
lost 30^ per cent. This operation was performed in a crucible 
6i platina ; the cover of which gave some indications as if a 
slight portion of the finer parts had been volatilized. 

Some of the compact species, after exposure to a red heat 
for one hour, experienced a diminution in weight of 30 per 
cent. 

(10.) The sulphuric, muriatic and nitric acids, aided by a 
long digesting heat, efiect nearly a complete solution of this 
substance. The quantity of the undissolved residuum is dimi- 
nished in proportion to the purity of the mineral employed. 

(11.) The nitrate of silver, as well as the muriate of barytes, 
produce no change in the solution of this substance in nitric 
add. 

. ( 19. ) The solutions of this substance in mmiatic and nitric 
acids, cannot be buought to crystallize. 

B. 

( 1 . ) I selected some of die crystals of this substance, as free 
as it was possible from extraneous matter. 50 grains grossly 
pcumded were exposed, in a platina o-ucible, to a red heat for 
one hour. They weighed, whilst still warm, ^^ grains, which 
is a loss of 26^ per cent. 85 grains of the same parcel, from 
which I had taken the former, exposed to a heat of longer 
continuance and greater intensity, were diminished in weight, 
at the rate of 30^ per cent. 

( fi. ) The powder still preserved its pure whiteness. It was 
transferred into a matrass, and nitric acid poured upon it, 
wiiich soon began to act upon it. The matrass was placed, 
for many hours, in a digesting heat. A solution of the whole 



53^ Mr. Gregor's Experiments m a mineral Substance 

of the substance, except a small portion, was effected. I added 
a few drops of muriatic acid, and continued the digestion.. 

(3.) The acid was now diluted with distilled water, and 
poured off from the residuum, which consisted partly of a fine 
spongy earth, and partly of fragments of quartz. It was caught 
on a filter and sufficiently edulcorated. The last portion of 
edulcorating water dropped through the filter of an opalish 
hue. 

The residuum, dried and exposed to a red heat, for tjen. 
minutes, = J^ of a grain, ^ of which consisted of fragments 
of quartz, -jj was found to be silica, and -^ alumina. 

( 1 . ) The clear solution and the edulcorating water were 
poured into a large matrass and boiled, and whilst boiling; ^e 
contents were precipitated, in white flakes, by ammonia^ 

( 2. ) When the ammonia had ceased to produce any further 
precipitate, the clear fluid was decanted, and assayed with 
carbonate of ammonia. But its transparency was not in the 
least disturbed. 

( 3. ) This clear fluid, together with the edulcorating water, 
with which the subsided precipitate had been washed, was 
gradually evaporated. When its volume was considerably di- 
minished, a separation of a spongy earth took place, more 
^piously than I had reason to expect, and the quantity of it 
was still further increased by a few drops of ammonia. This 
earth, thus separated, was suffidently edulcorated, and added 
to the former precipitate. 

( 4. ) The fluid was again evaporated, and at last transferred 
to a crucible of platina, and the salt reduced to a dry state : on 



' formerly supposed to be Zeolite^ Ac. 537 

redissolving this salt in distilled water a minute portion of 
eiarthy matter was separated, which, after edulcoration, was 
aidded tothe rest. The fluid from which it had been separated, 
and the edulcorating water, were again evaporated to dryness, 
and the ammoniacal salt expelled by heat, in a platina crucible. 
( 5. ) After the crucible had been made red hot, it was exa- 
mined. I discovered on the bottom of it, some traces of eardiy 
matter, and some spots, which had a glassy appearance. 
Water boiled upon it, dissolved nothing ; from which circum- 
stance, the absence of both of the fixed alkaline salts maty, be 
inferred. Neither did nitric add produce any alteration. A few 
drops of sulphuric acid ejected a solution of the substance, 
which axlhered to the bottom of the crucible. Ammonia preci- 
pitated from it a small quantity of earth, which was transferred 
to the rest, and the sulphate of ammonia and edulcorating 
water' were agaki evaporated and expelled by heat. A few 
spots of the same glazing still appeared. I had observed the 
same phasnomenon in a former experiment : but in that, as 
well as in the present instance, the substance, was in too small 
a quantity to become the subject of experiment. 

D. 

( 1 . ) Upon the precipitate ( C 1 ) , and the earths collected at 
different times, whilst they were in a moist state, I poured a 
solution of potash in alcohol mixed with distilled water ; in 
a short time, the greater part of it was dissolved. 

The clear solution was decanted, and the undissolved sedi- 
ment was transferred to a bason of pure silver, and boiled with 
a solution of potash. . 

( 2. ) When the potash ceased to act upon it, it was diluted 

MDCCCV. X X 



3^ Mr. GREiZMsni's EJi^mtntnki ^$n awmmd Substance, 

with ^ssfiilled watw wA deoanted from a hr^wiii po wder» wl^eli 
had subskied. This potwdtar edulcarated, dried, and ignited 
weighed -^oi^ grain ; ;{: of a graiOb>ms aluinina^i^ jitica^ aod 
•^ oxide of Iron. 

(:t.) Thfi fidutiioii effected by potash wa£i<ijecompoi5e.d and 
cedi^adived b}C' iBiiriatiP acid, and the contents of the solution 
were pired^toted by ammosoav The subsided prtepkate way 
ftcKiilcorated, 

(s. ) The flt&d and the 'odulcbirating twater were evaporated: 
to drjniitsa, and redtsaolved in distilled Water. Here agam, txi» 
my surprise^ a sepaoration tocdc place of a: whiter eartii!^ ttknw 
^MnduMr than is iDsual in cases whme aimmciiHaLi& employed aa 
% piwapitoDt. 

(3.) Thi» earth and ihe precipitate were edidcorated with 
distiUed water, until ils ceased to affect a solution of nitrate of 
mercury. Coltected, dried^ and ignitedy far one hour it weighed 

mhiisi itiU W0ai $/a^ YT- 

F. 

(1.) This earth was placed in a crucible of platina, and 
repeatedly mdistened with sulphuric acid» which was abstracted 
from it in the sand bath ; distilled water effected the sdiution 
of the vdiole, except a white powder which weighed, after 
ignition, 2-^ grains. It was proved to be sHica^ 

(9.) This acdution was now mixed with some acetat of 
potash and: gradually evaporated ; large and regular crystals \ 

of alum were from time to time formed. A small portion of 
which wdgbed after igniti<m ^ cf grain was deposited ; 



fwmnty nippased to be ZeotiUf CocL 539 

some Bulpkut of lime abo made its appearance, AK^eh washed 
Ynth diluted akohol and dried in a low faeat ces^ of a grai^. 

(d* } ^ portion of the fitad remained which neitliferthe addi- 
1km of potash nor the lapse of nahy weeks eould induce to 
crystaUlza Suspecting that it might oonlain glucine, I pred- 
pitaeed die contents by carbonat of aounonia, added tB excess, 
and shook the mtitmre tepeatedfy and strongly. The precipi- 
Cited earth was collected and die. fluid boiled, but it was found 
to ccmtain nothing but a minute partioa of alumma. 

( 4. ) The edulo(»ra«^d earth was nsdissolved in sulphuric acid, 
except f of s grain of ignited sfilica* 

The solution was mixed with a little potash, md gradually 
evaporated. Sulphat of of lime was separated at several times 
and after long intervals, which sufficiently washed and dried in 
a low heat ss ^. Some silica bUbo separated, but too minute in 
quantity to be ascert^ned by weight. The remaming fluid at 
length crysfidlkced into regulariy fisnrmed alunt. 

(5.) The wliok, therefore, of the 3^ ^ (E. 3.) eonsistad 
of dmnina except 9 J- of silica, and the Hme contaihed iu || of 
sulphat of Htne, whidh ttiay he eslAnaated: about -f^ of a grain ; 
line alumina, therefore, ear 99 ; the alumina in B. and D.^m^; 
the silica in B, D, and- F, ===3-1^ ; the oxide of iron ( D. ) 
=^, and lime F, ^; the volatile paints <iffhifir6ttlntaras33 ig} 
in the 50 grains employed. 

■ The sum total' of these is - « - - ^^^ 

Loss . ^ - - - - 2^ 

SO 

I have subjected tfiese cry stab, as well as^the harder spedes 
of this mineral, to analysis by means of direct solution in 

XX2 



^4P M^' Grii6or's Experiments on a mineral Substance 

sulphuric acid, and have found in each case the same fixed ingre- 
dients, viz. alumina, a small portion of silica, and a very mmute 
quantity of lime. Both these latter ingredients are, I think, 
essential to the composition of this fossil, as I have always dis- 
covered them in the purest specimens. In this mode of analysis 
I experienced the same difficulty and tediousness of delay in 
bringing the last portions of the solution to crystallize into 
alum. This anomalous circumstancel have reason to attribute 
to a particular combination, which takes plaCe between the 
sulphat of alumina and lime, silica, and potash. In my exami- 
nation of the compact species there was no appearance of the 
sulphat of lime imtil the last ; and in every experiment, previ- 
ously to the fresh appearance of crystals of alum, that had 
been long delayed, silica and sulphat of lime were deposited^ 

I forbear entering into any further details concerning my 
former experiments on this curious fossil, as I have reason to 
think that it will still require a more particular and minute ex- 
amination, on account of another ingredient which eluded my 
notice, and which may possibly impart to it its peculiar character. 
The scarcity of it has been hitherto a great, bar to my experi- 
ments ; I shall record, however, a few facts which I have 
lately observed, in the hope that at a future time I may be able 
to resume my examination of it. 

I was induced to pay more attention to the volatile ingre- 
dients of this substance.* With this view, I introduced some 

of the crystals into a small retort, adapted a receiver unto it, 

» 

* Mr. Humphry Davy> whose well known skill and sagacity have probably ren* 
dered the researches of another person superRuous, had, I found, been engaged in the 
analysis of a mineral which is thought to be ideoiical wifh the subject of these obser* 
vations. He informed me that he had observed a peculiar smelly and acid p^operries 
in the water distilled from the substance which he e^camined. 



formerly supposed to he Zeolite, &c. g^i 

and exposed the retort to a charcoal fire. The neck of the 
retort was soon covered with moisture, which passed into the 
receiver ; and I observed a white crust gradually forming in 
the arch and neck of the retort. 

On examination of the fluid in the receiver, it was found to 
have the same empyreumatic smell that I had observed before. 
It resembles very much the smell which that fluid is found to 
have which is distilled from the white crust that surrounds 
flint as a nucleus. 

It changed litmus paper to a faint reddish hue. It produced 
no change on a solution of nitrat of silver, and scarcely a per- 
ceptible one, on that of nitrat of mercury. 

The crust formed in riie neck of the retort consisted of thin 
scales, which after the vessel had been dried, were disposed 
to separate from the glass in some places, but in others they 
firmly adhered unto it. They were opaque, like white ena- 
mel, and reflected the colours of the rainbow. A portion 
of this subtance exposed to the flame of the blow-pipe upon 
charcoal turned at first black, and then melted into a globule, 
that exhibited somewhat of a metallic splendor which soon 
grew dull. This substance is soluble in water ; on evapora- 
tion of it, it assumes, at the edges of the fluid, a saline appear- 
ance, which, as the moisture evaporates, becomes earthy, 
opake, and white. Some of the solution changed litmus paper 
to a faint red. Lime and strontian waters produce in it 
white cloudsi which a drop of nitric acid removes. Muriats of 
lime and barytes produce no change in it. Nitrat and acetat 
of barytes disturb its transparency, the effect produced by the 
latter is more evident. Nitrat of silver produces no effect, but 
nitrats of mercury and lead cause copious precipitates, which 



^ Mr. Grboor's^ MJspminunU m « mmwU Substance 

«re white^ 9114 f^luU^^ in nitcic acid, PboBphat of amaonia 
anq[ $CK|a produced a whijte precipitatq. Oxalate tartritQ> aa4 
pru6»4t: of potaish did not aifect it, nor did aulphat of soda. 
Ammonia was dropped into it,, but the fluid preseyv^ it« 
tpanapavency. But carbonat of ammcmia in;sti»itly cauMd a 
w^te pce^^tate, which wa$ not redissolved by dsx exce&s of 
the precipitant ; up^ aorae of this subsided f^edpitate a con* 
centcated sdiatioa of potajsh was poured and shaken with it« 
but it was not sensibly diminished. But if afteir edulcoration k 
be dissolved in^ mtrjec acid, mA potash be added« no {Mrecipitate 
is: prod«iced- 

Carbonat of potash causes a white precipitate: when dropped 
into die aqueou3 sohiHon of the scaly 3ubliBiate. 

The 9upematanjfc fluid was poured off and gradually evapo^ 
rafeed, but it became repeatedly turbid, nor could I by means 
eiti»r of t^e filter ot AixA»\ prevent a. recurrence of the same 
effect. Nearly the 9KmB result takes place when carbonat of 
ammonia is used as the precipitant. 

Some of die white scales were moistened: with sulphucic acid. 
No vapour arose. 

Some of the precipitate obtained by means of carbonat of 
potash from the watery solution of this substance^ was, after 
suffident edulcoration, dissolved in sulphuric add ; liie solutiofi, 
on due evapor^ion, produced permanent crystals, some of 
whrch resembled alum, but others seemed to di6fer from it in 
external character. Ammonia decomposed the solution of 
them in* water, and a few drops of liquid potash dissolved the 
predpitirt:ed earth. The quantity was too small for further 
experiment. 

If distilled water be poured into the retort and: boiled iait^ so 



ftfrHoHy mppos»d to be ZeoSte<, tee. 345 

1 

as to dissolve what adheres to the neck and cavity of it, a fur- 
ther solution is effected, but differing in some measure from 
the solution of Iht sublimaite colle^^d from the neck of the 
vessel. TMs lastefr sdiution is foimd to contain lead. If nitric 
or mufittttid ^d be poured into <be i^etort, so as to diss^lte 
what stiU remains adhering to it, the presence of k^ad becoiftes 
more evident Whence does this metal arise ? I have reason 
to believe that it arises from the glass retort, which is corroded 
by the aidd of the fossil extricated by heat. But what acid is 
it? R dbes not seem tb be either the phosphoric or fluoric 
aci^, the latter of which beciune the first object of my stM^ 
pieion. 

The opinion which Mr. Davy suggested V& me seems more 
probable, that it is of vegetable origin. Oxalic acid, on the 
authority of Bergman, may be volatilized ; yet some of its 
properties are very extaraordinary and do not aceoifd with thi* 
idea. 

I decomposed the watery solution of the scsles by nit^at of 
lead, and after a sufficient edulcoration of the subsided precipi- 
tate, I dropped upon it some sulphurfe add. No futties \^ete 
perceptible. The stilphat of lead was separated by the fihfe^, 
aad the dear fltrid, which passed through it, was grhd^ially 
evaporalted; smaH ci^tftallizations were fbrrtied, the figure c^ 
which! cbuW wot ascertain ; some of them were exposed t& 
the flame of Ae blowpipe in a gold spo<m ; they dfid not butft 
» «d. «,r giv* out any empy^umatie StteD nor fu.., but 
tfiey asstimed bxi earthy appearance.* 

^ I sBbjected some of the Barnstaple mineral* with which Mr.RASHLixoH kindly fut^ 
nished me out of his cabinet, to e3q)eriment« with a view of ascertaining whether it 
woold prtdwc the isame volatilized ^aBne ctix$t, as the Stenn^ Gwyn fossil^ and t 
fi>iiBd that it cKd» 



344* -^^- Gregor's Experiments on a mineral Substance 

Uran-glimmer. 

I shall add a few desultory remarks upon the yellow and 
green crystals, which frequently accompany this fossil. 

I considered them to be the two species of Uran-glimmer, 
which had been examined by the celebrated Klaproth. 

The yellow gubic crystals are light. Their specific gravity, 
taken at temperature 45'' Fahrenheit, was 2,19. 

Exposed to the flame of the blowpipe on charcoal, they 
decrepitate violently. A piece of this substance is taken up by 
phosphate of ammonia and soda, without effervescence, and 
communicates a light emerald-green colour to the fused globule. 

By exposure to a red heat, this substance loses nearly a 
third part of its weight. It then becomes of a brassy colour. 

It is soluble in the nitric and muriatic acids : but I could pro- 
cure no crystallized salt from the solution of either of them. 

By evaporation to dryness, and redissolving the mass, some 

silica is separated. 

A. 

( 1 . ) A certain quantity of the yellow crystals were dis- 
solved in nitric acid. Muriatic and sulphuric acids successively 
dropped into the solution produced no sensible change. The 
contents of the solution were precipitated by ammonia, in white 
cjiots, mixed with some of a yellowish hue. Ammonia, added 
in excess, betrayed no sign of the presence of copper. 

( 2. ) The ammonia, on evaporation, was found to have held 
a portion of the mineral in solution. A fresh portion of am- 
monia dissolved more, but in a less quantity, at each succeeding 
affusion of it. 

(3.) The precipitate, which had resisted the ammonia, was 
boiled in a silver crucible, with a solution of potash in alcohol, 



formeriy supposed to he Zeolite^ &c. 345 

diluted with distilled water, and a considerable portion of the 
substance was dissolved by it : the potash and the ammonia had 
dissolved rather more than half of the fixed ingredients of it. 

( 4. ) The edulcorated residuum, which was of a dirty yellow 
colour, was transferred to a crucible of platina, and moistened 
with sulphuric acid, which was abstracted from it, in the sand- 
bath. The brownish-gray mass was elixated with distilled 
water, which dissolved nearly the whole of it. The residuum 
consisted of a white heavy powder, which, tried in different 
ways, was found to be sulphate of lead. 

( 5. ) The solution effected by sulphuric acid was greenish. 
On evaporation, a salt was produced, of uncommon brilliancy, 
resembling scales of mica, or silver leaf. These diminished in 
quantity at every fresh solution and evaporation, and at last 
they could not be reproduced ; but a confused crystallized mass 
remained. How far the platina crucible may have contributed 
to this phsenomenon I cannot ascertain. 

( 6. ) The solution of the saline mass was precipitated by 
potash, of a dark brown colour. The potash held nothing in 
solution. I redissolved the precipitate in nitric acid, and preci* 
pitated the solution by ammonia, of a bright yellow colour, 
peculiar to the oxide of uranium, with which it agreed in other 
properties. 

(7.) What was dissolved by ammonia (».) Amounted to 
nearly ^ part of the fixed ingredients. It was white, inclining 
to ash-colour. It tinged phosphate of soda and ammonia of a 
light green. It was soluble in sulphuric acid, except a few ge- 
latinous flakes. The solution was greenish; gradually eva- 
porated, it shot into a mimber of minute stellated crystallizations, 
whidi were circular, and c^isisted of rays diverging from a 

MDCccv. Y y 



S4i6 Mr. Gregorys Experiments on a mineral Stibsta?ice 

centre. They were, in general, colourless : a few of them were 
tinged of a smoke-colour. They soon became deliquescent. 
Upon evaporation, the same crystallizations were produced. 
After a time, some detached, regular, and permanent crystals 
were formed, which were colourless. Their figure I could not 
accurately ascertain. They were exposed to a red heat in a 
platina crucible. No ammoniacal vapour was perceptible. The 
crystals melted into opaque globules: some of these were 
transferred to a small glass, and distilled water was poured 
upon them. No solution took place, apparently : on shaking 
the glass, the globules fell to pieces into gelatinous flakes, which 
were white. Some of the supernatant fluid was tried with 
muriate of barytes, which produced a cloud. But neither am- 
monia nor prussiate of potash caused any change in it. It is 
soluble also in nitric acid : the solution formed a confused crys- 
tallized mass, which soon became deliquescent. Zinc, inunersed 
in it, caused the separation of white gelatinous flakes. Iron 
caused no change. Ammonia and potash threw down white 
precipitates, a portion of which were redissolved. The carbo- 
nates of soda, potash, and ammonia produced white precipitates. 
Prussiate of potash threw down the contents of the solution in 
distinct flakes, of the colour of mahogany ; and the solution of 
galls in alcohol caused a light yellow powder to subside. It is 
soluble also in muriatic acid; the solution is a very dilute green. 
It requires an excess of acid to hold the substance in solution ; 
which, after a time, deposits crystalline grains of a yellowish 
colour, which require a large quantity of water to dissolve them. 

Acetic acid does not dissolve this powder. 

( 8. ) What was dissolved by potash ( 3. ) was of an Isabella 
colour: it was tried with nitric, muriatic, and sulphuric adds. 



fonnerly supposed to be Zeolite ^ &c. 54,7 

rteither of which could dissolve the whole of it. What resisted 
the two former acids was found to be silica. That which re- 
mained undissolved by the latter, was silica and sulphate of 
lead. Evaporation of the latter solution, betrayed also the pre- 
sence of lime, in the state of sulphate. The nitric and muriatic 
solutions, on evaporation, deposited nitrate and muriate of lead ; 
and sulphuric acid dropped into them produced a small quan- 
tity of sulphate of lime. 

The nitrate and muriate of lead were decomposed by sul- 
phuric acid, and the lead reduced on charcoal. 

Ammonia precipitated what remained in these solutions, and 
redissolved a part of the precipitates, which agreed in properties 
with that substance before mentioned ( 2. ) ; the remainder was 
of a brighter yellow. But I could not bring the solution of it 
in nitric acid to crystallize. 

B. 
( 1 . ) Some of the yellow crystals, which had not the slightest 
appearance of being contaminated with extraneous matter, were 
dissolved in sulphuric acid. Silica was separated ; and the pre- 
sence of lime and lead proved by the appearance of their 
respective sulphates. 

• ( fi. ) If sulphate of ammonia is dropped into a solution of this 
mineral in nitric or muriatic acids, no change takes place, /m- 
mediately. But on evaporation, a yellowish crust is deposited, 
which is insoluble in water. A solution of carbonate of soda in 
water, boiled on it, becomes yellowish-brown, and the greater 
part of it is dissolved. The residuum, which is white, is reduced 
on charcoal to a globule of lead. What the carbonate of soda 
had dissolved was found to be oxide of uranium. Sulphuric 
acid alone^ does not produce tliis deposited crust. 



g^S Mr. Gregorys Experiments on a mineral Substance ^ &c. 

( 3. ) Some perfectly pure crystals were dissolved in muriatic 
acid. Some silica was separated. A few drops of sulphuric acid 
were dropped into the solution, which produced no immediate 
change : on evaporation a white powder separated, which con- 
sisted in part of sulphate of lime. The remainder, exposed to 
the flame of the blowpipe, was reduced to globules of lead. 

The solution was decomposed by ammonia, which redissolved 
a part of the precipitate ; and, after edulcoration, the preci- 
pitate was dissolved by nitric acid, and precipitated again by 
ammonia, which held a less quantity in solution. The edul- 
corated precipitate was now boiled with a solution of carbonate 
of soda, which dissolved a large portion of it. The solution 
was yellowish-brown, and contained oxide of uranium. What 
was undissolved by the carbonate of soda was dissolved in sul- 
phuric acid, and seemed to be the same substance as that wluch 
the ammonia held in solution. A. (s.) 

The scarcity of this beautiful mineral has precluded me from 
operating on such a sufficient quantity, as a regular and rigid 
analysis required. 

The substance, which is held in solution by ammonia, has 
some peculiar properties that seem to distinguish it from ura- 
nium. And if this mineral be the Uran-glimmer, I have cer- 
tainly detected the oxide of lead, lime, and silica in it, which 
have not hitherto been considered as ingredients of tliat fossil. 
The green crystals differ in no respect from the yellow, except 
in containing a little of the oxide of capper*- 

Creed» 
3une 14th, 1805. 



•^ 



PRESENTS 



RBCSIVBD MX TUK 



ROYAL SOCIETY, 



From November 1804 to July 1805; 



WITH TUi 



NAMES OF THE DONORS. 



1804* PRfiSEKTS. 

Nov. 8. Transactions of the Linnean Society* Vol. VIL 
London, 1804. 4» 

Transactions of the American Philosophical So* 
ciety> held at Philadelphia. Vol. VI. Part. I. 
Philadelphia, 1804. 4'' 

The Philosophical Transactions abridged. Vol. III. 
Part IV. and Vol. IV. 

General Zoology, by G. Shaw. Vol. V. London, 
1804. 8« 

Observations on the Plague, the Dysentery, the 
Opthalmy of £gypt» by P. Assalini, translated 
by A. Neale. London^ 1804. iz® 

A Journal of Natural Philosophy, by W. Nichol- 
son. No. 31^35. 

Dissertations, Essays, and Parallels, by J. R. Scott. 
London, 1804. 8<* 

The Philosophical Magazine, by A. Tilloch. 

No. 73—77- 

The Narrative of Captain David Woodard and 

Pour Seamen, who lost their Ship while in a 

Boat at Sea, and surrendered themselves up to 

the Malays, in the Island of Celebes. London, 

1804. 80 

15. Morborum puerilium Epitome, Auctore G. Heber- 

den. Londini, 1804. 8® 

Bibliotheque Britannique. No. 179-^204. 



DONORS. 

The Linnaean Society, 

The American Philoso* 
phical Society. 

Messrs. C. and R. Bald- 

. win. 
Mr. George Kearsley. 

Mr. Adam Neale. 



Mr. William Nicholson. 

The Rev. John Robert 

Scott, D. D. 
Mr, Alexander Tilloch. 

William Vaughan, Esq. 



William Heberden* 

M. D. F. R. S. 
Professor Pictetj F. R,/S. 



C 350 3 



PRESENTS. 

tz, Commentationes Societatis Regiae Sctentiarum 
Gottingensis ad A. 1800—3. Vol. XV. Got- 
tingxy 1804. 4* 

On the Cultivation and Preparation of Hemp« by 
R. Wissett. London, 1804. S® 

An Account of the Fall of the Republic of 
Venice, translated from the Italian, by J. Hinck- 
ley. London, 1S04. 8^ 
Dec. 6. Fasciculus V. of a Synopsis of the British Con- 
fervae, by L. W. Dillwyn. 
A Reply to the Animadveirsions of the Edinburgh 
Reviewers on some Papers published in the 
Philosophical Transactions^ by T. Young. 
London, 1804. 8^ 
The Philosophical Transactions abridged. Vol. V. 

Part I, 
Meteorological Journal kept at Nottingham-house, 
near the Athapescow Lake, from Oct. i, 1802, 
to May 21, 1804. MS. fol. 

A Journal of Natural Philosophy, by W. Nichol- 
son* No. 36. 
Report of a Medical Committee on the Cases of 
supposed Small -pox after Vaccination, which 
occurred in FuUwoods Rents. London, 1804. 8^ 
The Philosophical Magazine, by A. Tilloch. 
No. 78. 
13. State of the Thermometer at Quebec^ fkom Nov. 
I, 1803, to July 27, 1804. ^S- 
A Catalogue of Books contained in the Library of 
the Medical Society of London. London. 8°" 
20. A View of the Old Palace at Hampton Court. 
1805. 
^an. 10. Scriptores Logarithmici, or a Collection of Tracts 
on the Nature and Construction of Logarithms. 
Vol. V. London, 1804. 4* 

The Nautical Almanack for the Year 1809. 
London, 1804. 8^ 

The Philosophical Transactions abridged. Vol, 

V. Part IL 
A Journal of Natural Philosophy, by W. Nichol- 
son. No. 37. 
The Philosophical Magazine, by A. Tilloch. 
No. 79. 
17, A Meteorological Journal of the Year 1804, kept 
in London, by W. Bent. London, 1805. 8® 
24. Meteorological Journal kept on board the Marine 
Society's Ship in 1804. MS. fol. 

31. Annals of Medicine for the Years 1803 — 4, by A. 
Duncan, sen. M. D. and A. Duncan, jun. M. D. 
Vol. IlL Lustrum If. Edinburgh, 1804. 8** 
Nuovo Metodo di applicare alia Sintesi la Solu- 
zione analitica di qualunque Problema geo- 
metrico, di A. Romano. Venetia, 1793. S^ 



DONORS. 

The Royal Society of 
Sciences of Gottingen. 

Robert Wissett, Esq. 

F. R. S. 
John Hinckley, Esq. 



Lewis Weston Dillwyn» 

Esq. F. R. S. 
Thomas Young, M. D*. 

F. R. S. 



Messrs. C. and R. Bald- 
win. 
Joseph Colen, Esq. 

Mr. William Nicholson. 
Mr. Charles Pears. 

Mr. Alexander Tilloch. 

Lieut. Gen. Dwnes, 
F.R.S. 

The Medical Society of 
London. 

The Society of Anti- 
quaries. 

Francis Maseres, Esq. 
F. R. S. 

The Commissioners of 
Longitude. 

Messrs. C. and R« Bald- 
win. 

Mr. William Nicholson. 

Mr. Alexander Tilloch. 
Mr. William Bent. 
The Marine Society. 

Andrew Duncan, sen. 
M. D. and Andrew 
Duncan, jun. M. D. 

Sig. Antonio Romano. 



C 351 3 



PRSSBNTS. 



Feb* 7% Abbozzi di Fenomeni del Vesuvia> da iz Sept. 
17799 al so Agosto, >795« ^^ P* Antonio 
Piaggio. MS. 7 Vols. 4* 



Descrizione dell* Incendio del Vesuvio degli 8 
Agosto i779> dal P. Antonio Piaggio. MS. 4^ 

The Philosophical Transactions abridged. VoL 
V. Part 111. 

A Journal of Natural Philosophy, by W. Nichol- 
son. No. 38. 

The Philosophical Magazine^ by A. Tilloch. 

No. 80. 

21. Acta Academiae Scientiarum Imperialism Petro- 

politanx pro Anno I779> P^**^ prior et posterior; 

et 1782 Pars posterior. Petropoli i782> 1786. 

Indian Serpents. Vol. II. Part II. 



Observations on Cancerj by E. Home. London, 
1805. %• 

28. The Report of R. Mylne on the proposed Im- 
provement of the Drainage and Navigation of 
the River Ouze« by executing a straight cut 
from £au Brink to King's Lynn. London, 
1702. 40 

Eau Brink, new River, or Cut Deed Roll, stating 
the Opinion (in the Nature of an Award) of 
Jos. Huddart, Esq. London, 1 804. 4* 

The Philosophical Transactions abridged* Vol. 
V. Part IV. 

Important Discoveries and Experiments elucidated 
on Ice, Heat and Cold, by J. Hall. London, 
1805. 8« 

Mar. 7. A Journal of Natural Philosophy, by W. Nichol- 
son. No. 39. 

The Philosophical Magazines by A. Tilloch. 
No. 81. 
14. Transactions of the Society for the Encourage- 
ment of Arts, Manufacures, and Commerce. 
A'ol. XXII. London, 1804. 8"" 

A short Account of the Cause of the Disease in 
Com, called by the Farmers the Blight, the 
Miidtw, and the Rust London, 1805. 40 

Observations tendant a prouver que TAcide mu- 
riatique oxigene n'est pas une Combinaison de 
I'Acide muriatique ct de I'Oxigenc, par S. 
Pugh. Rouen, 1804. ^^ 

21. Memoires de; TAcademie Royale des -Sciences et 
Belles Let tres, 1801 • Berlin, 1804. 4^ 



DONORS. 

The Right Hon. Sir 
Joseph Banks, Bart, 
k. B. P. R. S. in con- 
sequence of the direc- 
tions of the late Right 
Hon. Sir William Ha- 
milton, K. B. 



Messrs. C. and R. Bald- 

win. 
Mr. William Nicholson. 

Mr. Alexander Tilloch. 

The Imperial Academy 
of Sciences of Peters* 
burg. 

The Committeeof Ware- 
houses of the East-In- 
dia Company. 

Everard Home, Esq. 
F. R. S. 

Robert MylQe« Eaq^ 
F. R. S. 



Messrs. C. and R. Bald- 
win. 
Rev. James Hall, A. M. 

Mr. William Nicholson, 
Mr. Alexander Tilloch. 

The Society for the En- 
couragement of Arts, 
Manufactures, and 
Commerce. 

The Right Hon. Sir Jo- 
seph Banks, Bart. 
A., o. I . K.. S. 

M. Pugh, of Rouen. 



The Royal Academy of 
Sciences of Berlin. 



C353 n 



PRESENTS. 

Astronomical Observations made at the Royal Ob- 
servatory at Greenwich, from 1750 to 1 762, by J. 
Bradley, Vol. II. together with a Continuation 
of the same by N. Bliss. Oxford, 1805. fol. 

Astronomisches Jahrbuch fiir das Jahr 1807, von 
J. £. Bode. Berlin, 1804. 8<» 

Journal de Chemie et de Physique^ par J. B. van 
Mons. No. 15. 
Jpril 4. Connaissance des Tems pour V An 15, publiee 
par le Bureau des Longitudes, Paris, 1804. 8* 

Letters on Chinese Literature. London, 1804. 8* 

25. Elementary Treatises on the fundamental Prin- 
ciples of practical Mathematics, by S. Lord 
Bishop of Rochester. Oxford, 1801. 8^ 

Euclidis Elementorum Libri XII. priores, edidit, 
auxit et emendavit S. Episcopus Roffensts 
Oxonii, i8o2. 8^ 

Euclidis Datorum Liber, nee non Tractatus alii ad 
Geometriam pertinentes ; edidit S. Episcopus 
Asaphensis. Oxonii, 1803. 8° 

Plantarum Guianae rariorum Icones et Descrip- 
tiones hactenus tneditx, Auctore £• Rud^e. 
Vol.1. Londini, 1805. fol. 

Chirurgical Observations relative to the Bye, by 
J. Ware. London, 180$. 2 Vols. 8^* 

A Journal of Natural Philosophy, by W. NichoU 
son. No. 40. 

The Philosophical Magazine^ by A. Tilloch. 
No. 82. 

Journal de Chemie et de Physique, par J. B. van 
Mons. No. 1 6. 
May 2. The Philosophical Transactions abridged. Vol. VI. 
Parti. 

A Journal of Natural Philosophy, by W. Nichol- 
son. No. 41. 

The Philosophical Magazine, by A. Tilloch. 
No. 83. 
9. Plants of the Coast of Coromandel, by W. Rox- 
burgh, M. D. y<A. II. No. 4. 

16. Part the First of the General Survey of England 
and Wales, by the Surveyors of his Majesty's 
Ordnance, under the Direction of Lieut. Col. 
Mudge. 4 Sheets. 

Table of Meteorological Observations on Sea and 
Land in various Climates, by James Horsburgh. 
MS. 4* 

Kongl. Vetenskaps Academiens Nya Handltngar. 
Tom. XXIII, for Ar 1802, 4th Quarter; Tom. 
XXIV. for Ar 1803; and Tom. XXV. fdr Ar 
1804, ist and 2d (garters. Stockholm. 8« 
to. The Philosophical Transactions abridged. V<rf>VI» 
Part Ilr 



DONORSt 

The Delegates of the 
Clarendon Press at 
Oxford. 

Mr. J. E. Bode, F. R. S. 

M.van Mons, of Brussels. 

Le Bureau des Longi- 
tudes de France. 

Antonio Montucci, 
LL.D. 

The Lord Bishop of St. 
Asaph, F. R. S. 



Edward Rudge, Esq. 
F. R. S. 

JamesWare, Esq. F. R. S. 

Mr. William Nicholson. 

Mr. AkxaAder Tilloch. 

M.van Mons, of Brussels. 

Messrs. C. and R. Bald- 
win. 
Mr. William Nicholson. 

Mr. Alexander Tilloch. 

TheComraittee of Ware- 
houses of the East-In- 
dia Company. 

Lieut. Colonel Mudge, 
F. R. S. 



Alexander Dalrymple, 
Esq* F. R. S. 

The Royal Academy of 
Sciencesof Stockholm. 



Messrs. C. and R* Bald* 
win* 



C353 3 



PRiSBNTa. 

yun€ii* Werneria» or Short Characten of Earths. London, 
1805. 12^ 

Reflections on the Commerce of the Mediterranean» 
by J. Jackson. London, 1804. 8® 

A Journal of Natural Philosophy, by W. Nichol- 
son. No. 42. 

The Philosophical Magazine, by A. Tilloch. 
No. 84. 
20. Plates 15, 16 and 17 of the 4th Volume of Vetusta 
Monumenta. 

The Critical Review, February— May 1805. 8^ 

Relazione del Fenomeno accaduto in Scilla 1790, 

la Mattina de* 24 Marzo» dal Dr. Rocco Bovi. 

MS. foU 

17. Roval Humane Society. Annual Report, 1805. 

London. 8^ 

A Genend View of the Writines of Linnseus, 
by R. Pulteney ; the second Edition, with Ad- 
ditions and Corrections, by W. G. Maton* 
London, 180^. 4* 

Plantarum Guianae rariorum Icones et Descrip- 
tiones hactenus ineditK, Auctore £. Rudge. 
Faciculus IL et IIL 
yuly 4« A complete Collection of Tables for Navigation 
and Nautical Astronomy, by J. de Mendoza 
Rios. London, 1805. ^ 

The Philosophical Transactions abridged. Vol. Vl. 
Part HI. 

A Journal of Natural Philosophy, by W. NichoU 
son. No. 43. 

The Philosophical Magazine, by A. Tilloch* 
No. 85. 

The Critical Review, June 180^. 

Sulla Inutilitil della Questione mtomo alia Misora 
delle Forze vive per la Risoluzioni de' Problem! 
dinomici, Memoria dell* Ab. A. Zendrini. Ve- 
nezia, 1804. 8^ 



DONOati 

The Author. 

John Jackson, Esq. 

Mr. William Nicholson. 

Mr. Alexander Tilloch. 

The Society of Anti* 

quaries. 
The Editor. 
Don Rocco BovL 



The Royal Humane So- 
ciety. 

William George Maton, 
M. D. F. R. S* 



Edward Rudge, Esq, 
P.R.S. 

Joseph de Mendoza Rios, 
Esq. F. R. S. 

Messrs. C. and R. Bald- 
win. 
Mr. William Nicholson. 

Mr. Alexander Tilloch* 

The Editor. 
Abbate ZcndrinL 



MDCCCV. 



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INDEX 



TO TMt 



PHILOSOPHICAL TRANSACTIONS 



t 



FOR tHE YEAR 1805. 



I » *■ 



page 

j4i)//£5/(7iV of sulphuric add and of alcohol to glass, - - TsU 
i.fci I » " ■ oFmercury to^gla^,* -^ • - - * - 75 

*(o 6t'her dubstaBces, - . .- 7^ 



I ' '* ■ I 



JM&kntum, variations of its density, >- .- - 9t 

Asteroid^ term applied to the stw lately discovered by Mr. 
Harding, - - ' - - - - 57 

AHraclion and repubion, apparent of floating bodies, - 7S 

1 > '» • * * . . ' . 

Barometer^ its diurnal variation at sea between the tropics, 177 

ri fyjwj ) *■! i • ■■ ni ii « jdoes iiot appear 4^n Bh6fe, - 1 J 1 

;B^722atc<rrt4t'&nnedi)bcmi dragcm's bl^^ • * i^i 

JStnd^ its <tempera^H». dii vmiioim ;aiiiin»ls; < • -* « , ^^ 

Mcracic acidf its -use in ihe analysis of -stones that oontaui a 

fixed alkali, - - , - - - 231 

Buds^ on the reproduction of, • • - 257 

Cawphory experiments upon it ivitli suljpkuric acid, - ^2 

Carbonaceous substances acted upon by nitric acid yield a sub- 
stance resembling tannin, y - - * 215 
Carlisle, Antho^y^ £sq« Qroanian Lecture on rmuscular . 
"tootion,"* . " • '" - ^ . ' . i* 

-7-; '- ^- 'On tbe pliysiolqgy-of tlie sta^pes^one 

^ tff thetones (rf*th6 organ ftfliearing,; deduced from a compa- 
rative v^ew df5ts structure, and uses, in different animals, I9X 
(^HiiNEVix," Richard, Esq. On (he action of platina and 
' inercufy upon eac^ other^ - - - - * 104 

Cohestjon vfjluids^ essay oa, - - - - 65 

Coluntdla^ a bone in the ear of birds, . - . 205 

Z S 



INDEX. 

page 
Conducting powers^ relative of platlna, palladium, silver, and 

copper, - • - - . -S29 

Crimping offish^ experiments on, - - - S3 

Cfyrsialline lens of the eye^ probably muscular, - - 14 

Davy, Humphry, Esq. An account of some analytical expe- 
riments on a mineral production from Devonshire, consisting 
principally of alumine and water, ' * - ' * . - 155 

. On a method of analyzing stones con- 
taining fixed alkali, by means of the boracic acid, «> 231 

Diameters^ spurious, of terrestrial objects, - - 44i 51 

:^ differ according to the portion of miiTor 

employed to view them^ . • »- ; . . • . • - $s( 

of celestial objects, , - •-.. 54f 5& 



' ' criterion for distixiguishing spurious from real, . . i£ 

Dragon' J 6/00^ experiments on, .,,..•- - - igj 

' E 



4 < i • 



Elevation ojfiuidsy by adhesion, -* . - - 7P. 

Expansion^ comparative, of platlna, palladiunii and steel, • 329 

pLiNDEks, Matthew, Esq. GoikerHifig thediSe renc es In 

the magnetic needle, on board the Investigatot, arising from 
\ an alteration in the direction of the 8kip*s hsad, • : 18^^ 

Fluids^ cohesion of, - .. - . t . ; : - •. .»/ ,• j : 65^ 

G ^ 

Gregor, Rev. William. Experiments on a mineral sub- 
stance, formerly supposed to be zeolite ; with some remarks , 
on two species of uran-glimmer, - - -^ SSI 

H . •• . •■ .. 



t ' J . 



Harding^ Mr. his star observed by Dr. Herschel, * - , . 57 

Hatghett, Qharlesi Esq. On an artificial substance, which 

possesses the principal characteristic properties of tannin, 211 
■ Additional experiments and re- 
marks on the same substance, • - * 2^5 
Hearty malformation of, in an infant, ' - - . - 2S8 
Herschel, William, LL. D. Experiments for ascer^iaing 
how far telescopes will enable us to determine very small 



INDEX- 

page 
angles, and to distinguish the real from the spurious diame- 
ters of celestial and terrestrial objects : with an application 
of the result of tliese experiments to a series of observations 
on the nature and magnitude of Mr. Harding's lately disco- 
vered star, - - - - - -31 

Herschel, William, LL. D. Experiments on apparent mag- 
nitudes of pins heads, - - - « 32 

* globules of sealing wax, 33 

-: :: of silver, 35, 44 



' — qf pitch, bees- 
wax, 8cc. - - ' - - - - 36 
■ illuminated globules, 40 



globules of quicksilver, 48 

— — — On the direction and velocity of the 

motion of the sun and solar system, . . . «. . s^^^ 

Observations on the singular figure of 



the planet Saturn, . .. - • -, • - 872 

Hibernalion of animals^ remarks on, - - - 1 7 

HoRSBURGH, J. Esq. Abstract .of observations on a diurnal 

variation of the^ barpmeter between the tropics, «* 1 7 7 

Jly acini hs found among crude platina, - - 3 1 1 

I 

^Jbisy Egyptian; mumvcAts off - - - - 264 

-^ — two species, --,--. jgg 

Indizo^ yields a tanning substance by action pf nitric add, 294 

Iridium^ ofe of, mi\ed with crude platina, - - 317 

JunOf its magnitude estimated byv Dr. Herschel, - - 61 

'KnichT, Thomas Andrew, Esq. Concerning the state in 

which the true sap of trees is deposited during winter, - 8S 
.— ^ ' On the reproduction of buds, 257 

Lttcteals^ whence they receive their' ftuids, - - 8 

Lampadius\ observations on his formation of sulphur-alcohol, 11 5 
'Lane, Timothy, Esq. On the magnetic attraction of oxides 

of iron, *- - - - • -281 

Z^oi^^i contain three kinds of vessels, • - • 100 

Lecture^ Croonian, - - - - - I 

Lymphducts arise from cellular membrane, - « 8 



INIDEX. 

Magnetic needle observed to vary on ^hip-board, according to 

the posrtion of thfe sbip's head, ^ - - 186 

MarfMt^ a peculiarity in the bones of its earr, « - 204 

Mercury^ its adhesion to glass and other bodies, - S6 
Mirror of reflecting telescopes^ boiv its difiercnt parts afiect the 

spurious diameters of objects, - ^ - - 46 
MorveaUj remarks on his experiments upon the adhesion oT 

metals to mercury, • - - - - 76 

Mummies^ account of two of ttie Egyptian Ibis, - - 264 

Muscles^ often both red and colourless in the same animal, - 4 

»- their bulk varied by exertion, - ~ - - SJ 

— their specific gravity altered by crimping, - S3 

— their irritability destroyed by various agents, - S6 
their cohesive attraction is less when they cease to be 



irritable. 



3 



MvsHET, Mr. David. Experhnents on wootk, - 163 

N 

^trves dii^tributed in greartet proportion to voluntary muscles, 

than to Other parts, except the organs of sensation, • 'S 

■■■ their extreme fibrils transparent, . • 9 

■ possess powers of restoration, « - * to 

O 

Xharia deficient in a Full grown womaUi - • tiS 



Palladium^ attempts to form it artificially, • - I06 

- — — ^ by Tromsdprff and Klaproth unsuoBessCuli 111 

' out of lOOD atteiQptSy four successful, • ' 112 

— — — * its compound nature supported by Ritterj - II3 

on the disccrvery of, - - • 316 

r- the separation of, . \- - - • 322 

detonating prussiate of, •• ,• *- 328 

— — • its conductiK^g power, • • - 529 

reasons for considering it a simple metal, • 325 

P£ARs, Mr.Xjharles. The case of a full grown woman in 

whom the ovaria were deficient, » .. . jfiS 

Pearson, John, Esq. Some account of two mummies of the 

Egyptian Ibis, one of which was in a Femarkably perfect state^ 264 



INDEX. 

Pessntus^ a ()de)»li»r bone so named in the ear of the marmot 
and Gn'med-iHgi * - - - - 504 

PicoTT, Bdwarh, Esq. "An mve»t?gatton of all the changes 
ef the variable star in~Sobieski*s Shield, from five ye^rs ob« 
servations^ exhibiting its proportional illuminated parts, and 
ks irregularities of n>tatiert ; with conjectures respecting un- 
enlightened heavenly bodiesi - ' ' • - 131 

P/a/iW, on the fusioh of it, - - - - lofl 

•— precipitated by g^reen sulphate of iron, under what cir- 

cumstance^) -•^ - - - 117 

■ . how to be united most adviinta^eously with mercury, \2Q 

' m other methods, • • - • 123, fctf. 

iCepulsion^ apparent oriloating bodies, - - - 78 
Richlet\ remarks upon his attern^ts to combine platina with 

: mercury^ - - . - - •* lit 

RiUer's gaJivanic ^irra^gem^nt of metaU mA nlloya, ^ its 

Ro$e and Gghlen^ Messrs. attempt to form palladium, ^ 106 

/2oo/4i t];ieu m^da 4^ eJVQWths • * - • ^ 

. , S 

Sap^ aqueous, from high incisio^i sweeter and heavier than 
from low incision^ . - - - . . • g^| 

■ *■ • . true, concerning the state in which it is deposited during 

winter, - - - . - - %t 

iSahim, dn the singular figuk*e of that planet, - - ^8 

STANDEKf, Mr« ^uoh Chudlei'ch. A desqriptioB of msX- 

formation in the heart of an infant, -^ * - j! j^t( 

Stapes y the physiology of, " - - - - I98 

the bone described, * - - - 201 

iS/^r, oa th^ . magnittti^e ^f that lately cti^cfiYe|!e4 t>y Mr* 

Harding, ... . • SI, 55 

variable in Sobieski's Shield,* - - • 131 

^eel^ experiments on that called w^oXz^ «* - 163 

tSu/^Aur^-ar^coir^/ of Ivamp^idius^ - .1 . ** • n^ 

4$uiAi oh the^directibn and velocity of its motion, ^ itSS 

T 

Tanniriy on a substance which resembles it, - . 811 

properties of that substance, - - - Sfl5 

■ formed by action of nitric acid on carbonaceous suhstaAces, 2 15 

■ whether animals Y^efc^e» 

or mineral, - - - -. - . . ^ SXfl 



INDEX. 

Tannin f formed by action of nitric acicJi on substances reduced 
to the state of coal, whether by fire, or by sulphuric acidi 219 

'' additional remarks on it, - - - 2iS 

its indestructibility, - - - - f 86 

— its imputrescibility, - • - - 288 

on the destructibiiity of various kinds of natural tannin, 288 

artificial substance distilled, . . « irgg 

— — — — — : formed by action of nitric acid on va- 
rious substances not carbonized, - *. - 295 

probably formed by simple 



T ' 9 



exposure of some substances to a certain temperature, • ^02 
Telescopes^ experiments on their power of ascertaining the mag* 

nitudes of very small celestial objects, - - 31 

Torpedo J its battery probably governed by a vol untary muscle, 11 

u 

UmU' glimmer, experiments on, - » • 331 

Variation of compass on board ship, arising from position of the 
^ ship's head, - . - . . - . igfi 

*^«r of the magnetic needle at Sootterset-^hcmse, at the end 

of the Meteorological Journal, • ! - - - [27] 

• • • • 

w 

Wavellife, on a fossil from Devonshire so calledt * 155l 

WoLLASTON, William Hyde, M. D. On the discoveiry of 
' palladium ; with .observations on other substances foiind with 

platina, - , - - - ' - . ^l 316 

Wood^ winter-felled more dense than summer-felled, - 93 

WooiZj experiments on, ^ - * . • ' . I63 



• » . 



Young, Thomas, M;D; An essay on the cohesion of fluids, 65 

Ziolite^ experiments on a mineral substante resembling it, I55, 53 1 

'^ » ■ :— = =— yielding a peculiar 

, Mblimate, . * ' . . . . 334 

'^— properties of the sublimatei - - ^341 



mssssBaammmmaaBSsmBBmmm 
From ibt Press of 

W. BULhtEH ^ Co. 

doveland-Row, St yam$t*s*' 



METEOROLOGICAL JOURNAL, 



KEPT AT THE APARTMENTS 



or THB 



ROYAL SOCIETY, 



IT O&DBH OF TBI 



PRESIDENT AND COUNCIL. 



no 



METEOROLOGICAL JOURNAL 

for January, 1804. 



1804 



Six's 
Therm, 
least and 
greatest 

Heat. 



Jan. I 

2 

3 
4 

5 

6 

7 
8 

9 
10 

II 

12 

>3 
»4 

'S 

16 



37 

43 
36 

42 

32 
40 

30 

35 
30 

38 
28 

34 

27 

35 

27 
36 

28 

42 
40 

45 

JS 

43 
49 
47 
52 
5' 
54 
48 
55 
50 
53 



Time. 



H* Mt 



8 





2 





8 





2 





8 





2 





8 





2 





8 





2 





8 





2 





8 





2 





8 





2 





8 





2 





8 





2 





8 






Therm, 
without. 



2 O 

8 o 

2 O 

8 o 

2 O 

8 o 

2 O 

8 o 

2 O 

8 o 

2 O 



37 

43 

39 
42 

32 
40 

3i 

35 

32 

38 
28 

34 
28 

35 
32 
36 

39 
42 
38 
45 
35 
43 
45 

49 
52 

5* 
51 
54 
54 
55 
50 
53 



Therm, 
within. 



56 

53 
56 

5* 
53 
50 

49 

5» 
49 

48 

5* 
47 
5« 

48 
5° 
49 
52 
48 

50 
50 
5a 
52 
54 
53 
55 
53 
56 

54 
57 



Barom. 



Inches. 



Hy- 
gro- 
me- 
ter. 



29*73 
29,82 

29^82 

29,92 

30,13 

3«>'>5 
36,16 

30,12 

29,85 

29,72 
29,76 

29,79 
29,82 
29,72 
29,56 1 85 



*9'55 
29,68 

29>73 
29,92 

29*99 
29192 

29,88 

29,64 

29,48 

29,32 

29,22 

29.25 

29>43 
29,56 

29,54 

29,51 

29>45 



o 

81 

86 

9» 

83 
88 

83 

83 

83 
88 

92 
85 
83 
89 
85 



89 

9' 

9> 

84 
80 

90 

96 
88 
96 

95 

9i 
8 

9 
96 

2i 



I 



Rain. 



Inches. 



0,132 



o**3S 



0,023 
0,060 
0,197 
0,075 



Winds. 



Points. 



NNE 

NNE 

NE 

NE 

NE 

NE 

E 

ENE 

W 

w 

WNW 

NW 

W 

WNW 

s 

SSE 

£ 
SE 
SE 
SE 

E 

£ 
SE 
SSE 

S 

S 

S 

S 

S 

S 

E 
SSE 



Str. 



2 
1 

2 
2 



2 
2 
2 
2 
2 
2 
I 
1 



Weather. 



Cloudy. 

Cloudy. 

Cloudy. 

Fine. 

Fair. 

Fair. 

Fair. 

Cloudy. 

Snow. 

Cloudy. 

Fine* 

Fair. 

Cloudy. 

Cloudy. 

Cloudy. 

Cloudy. 

Cloudy. 

Cloudy. 

Cloudy. 

Cloudy, 

Cloudy. 

Cloudy. 

Cloudy. 

Rain. 

Cloudy. 

Cloudy. 

Rain. 

Rain. 

Cloudy. 

Rain. 



C33 











METEOROLOGICAL JOURNAL 














for January, 1804. 








Six'a 


Time, 


Thi,rm. 


Thrrm. 


Barom. 


Hy- 


Rain. 


Windi 


1* 






Therm. 






\vith')'.it. 


within. 




rro- 












leatt and 























i8o4 


grcatcit 






— 






me- 
ter. 








Weather. 


















Heat. 


H. 


M. 








Inches. 




Inches. 


Poinis. 


Str. 

I 




Jan. 17 


e 

49 


8 





49 


5$ 


29,41 




95 




E 


Rain. 




54 


2 





54 


$7 


*9*37 


94 




SE 


I 


Rain. 


18 


50 


8 





SO 


57 


29,58 


92 


0,025 


S 


2 


Cloudy. 




51 


2 





S» 


58 


a9>55 


9» 




S 


2 


Cloudy. 


«9 


47 


8 





49 


57 


*9>7« 


94 




S 


I 


Cloudy, 




53 


2 





SO 


58 


29*54 


92 




SE 


I 


Cloudy. 


20 


48 
50 


8 

2 






48 
50 


56 


29,30 


84 
84 


0,265 


SSW 
SSW 


2 
2 


Cloudy.r*;»*»»wind 
Cloudy."- ^'"*''- 


21 


45 


8 





SO 


56 


*9»43 


94 


0,055 


s 


2 


Cloudy. 




54 


2 





$4 


58 


29.49 


94 




s 


2 


Cloudy. 


22 


48 


8 





48 


56 


29,38 


89 




s 


2 


Fine. 




53 


2 





5| 


$9 


29,46 


78 




sw 


2 


Fair. 


*3 


46 


8 





46 


$6 


*9>7i 


90 


0,158 


sw 


1 


Fair. 




52 


2 





$« 


58 


2978 


84 




ssw 


2 


Cloudy. 


24 


50 


8 





50 


S6 


29,52 


88 




SSE 


2 


Cloudy.r»f«rf> r''^ 
Fair. •- i"t mght. 




53 


2 





$3 


S8 


29,41 


83 




SSE 


2 


25 


48 


8 





48 


56 


29,37 


90 




SE 


2 


Cloudy. 




5* 


2 





S* 


5* 


29^34 


94 




SE 


2 


Cloudy. 


26 


47 


8 





48 


56 


29.18 


9» 




SE 


2 


Cloudy. 




5* 


2 





$« 


58 


29. '7 


83 




S 


2 


Cloudy. 


27 


47 


8 





47 


57 


29,01 


92 




SSE 


I 


Rain. 




5« 


2 





51 


58 


29,12 


88 




S 


1 


Cloudy. 


28 


47 


8 





5« 


56 


28,88 


92 




s 


2 


Rain. 




53 


2 





S> 


57 


28,68 


93 




S 


2 


Rain. 


29 


45 


8 





45 


56 


*9'77 


81 


0,170 


WNW 


2 


Fair. 




51 


2 





5« 


58 


30,05 


77 




w 


2 


Fine. 


30 


43 


8 





47 


57 


30,18 


9' 


0,068 


SSE 


1 


Cloudy. 




51 


2 





S« 


$7 


30,06 


90 




S 


2 


Cloudy. 


3> 


48 


8 





50 


56 


29,78 


90 


0,210 


SSE 


2 


Cloudy. 


• 


54 


2 





54 


58 


29,68 


9> 




S 

• 


2 


Cloudy. 



a 2 



C4:] 









METEOROLOGICAL JOURNAL 










for February, 1804. 


' 




Six's Time. 


Therm. 


Therm. 


Barom. 


Hy. 


Rain. 


Winds. 






Therm. 






without. 


within. 




gro- 










1 

i 1804 


least and 
greatest 














me- 
ter. 








Weather. 




« 
















Heat. 


H. 


M. 








Inches. 




90 


Inches. 


Points. 


Str. 
1 




Feb. I 




45 


7 





45 


57 


29,62 




ssw 


Cloudy. 




s» 


2 





5» 


5f 


29>55 


82 




ssw 


2 


Fair. 


2 


4+ 


7 





44 


56 


29.47 


89 


0,160 


s 


I 


Rain* 


• 


50 


2 





50 


58 


29^57 


77 




w 


1 


Fair. 


3 


4S 


7 





45 


56 


29^38 


92 


0,310 


s\v 


I 


Rain. 




49 


2 





49 


57 


^9>45 


78 




wsw 


1 


Cloudy. 


4 


34 


7 





34 


54 


29,41 


83 


0,022 


WNW 


1 


Cloudy. 




38 


2 





37 


55 


29,61 


87 




NW 


2 


Fair. 


5 


3» 


7 





32 


5* 


30.05 


83 




WNW 


2 


Fair. 




43 


2 





43 


55 


*9.93 


77 




WNW 


2 


Fair. 


6 


»7 


7 





27 


52 


30,10 


76 




NW 


2 


Pine. 




32 


2 





3* 


54 


30,13 


7» 




NW 


2 


Fine. 


7 


*5 


7 





26 


49 


30,34 


87 




NNE 


2 


Cloudy. 




35 


2 





35 


52 


30,46 


82 




NNE 


» 


Fair. 


8 


z6 


7 





28 


48 


30,49 


84 




WNW 


1 


Cloudy* 




40 


2 





39 


50 


30,37 


80 




W 


1 


Cloudy. 


9 


39 


7 





43 


49 


30,05 


93 


0,090 


sw 


1 


Cloudy. 




50 


2 





48 


52 


29,95 


92 




sw 


1 


Rain. 


10 


43 


7 





43 


S« 


29,68 


95 


0,123 


wsw 


I 


Fair. 


• 


S« 


2 





5* 


53 


29«55 


84 




s 


2 


Cloudy. 


11 


43 


7 





43 


5' 


29,05 


9» 


0,310 


ssw 


2 


Rain. 




50 


2 





48 


53 


29,05 


92 




w 


1 


Rain. 


12 


42 


7 





4* 


5a 


29.65 


93 


0,252 


NE 


1 


Cloudy. 




44 


2 





39 


52 


30,02 


78 




NE 


I 


Snow. 


13 


H 


7 





3« 


50 


30,26 


79 




NNE 


2 


Fine. 




36 


2 





36 


53 


30,3* 


74 




NE 


2 


Fine, 


H 


27 


7 





28 


48 


30,38 


78 




NNE 


2 


Fine. 




36 


2 





36 


50 


30,37 


69 




NE 


2 


Fine. 


>5 


*7 


7 





28 


48 


30,39 


85 




NE 


1 


Fine. 




4> 


2 





41 


5> 


30,35 


86 




N 


1 


Cloudy. 


16 


35 


7 





36 


49 


30,32 


90 




NNE 


1 


Cloudy. 




4» 


2 





41 


5« 


30,30 


JiL 




NNE 


I 


Cloudy. 



C53 







• 


METEOROLOGICAL JOURNAL 








i 


for February, 1804. 




Six's 


Time. 


Therm. 


Therm. 


Barom. 


Hy- 


Rain. 


Winds. 






Therm. 






without. 


within. 




gro- 








i8o4 


least and 
greatest 














me- 
ter. 






Weather. 




















Heat. 


H. 


M. 








Inches. 




Inches. 


Points. 


Str. 


• 


Feb. 17 



29 


7 





30 


48 


30,32 




88 




NNE 




Fine. 




3B 


2 





37 


51 


30,33 


74 




NNE 




Fair. 


18 


34 


7 





38 


48 


30,20 


89 




N 


2 


Cloudy. 




42 


2 





42 


52 


30,31 


n 




NE 


2 


Fair. 


19 


33 


7 





35 


49 


3o»33 


91 




NE ■ 




Cloudy. 




43 


2 





43 


51 


30,28 


87 




NNE 




Cloudy. 


20 


38 


7 





38 


50 


30,34 


92 




NE 




Cloudy. 




44 


2 





44 


52 


30,37 


85 




NE 




Cloudy. 


21 


38 


7 





38 


50 


29,48 


82 




NNE 




Cloudy. 




46 


2 





46 


53 


30,51 


79 




N 




Cloudy. 


22 


42 


7 





42 


52 


30,46 


82 




N 




Cloudy. 




46 


2 





46 


53 


30.41 


78 




NNW 




Cloudy. 


23 


58 


7 





38 


5« 


30,25 


86 




NNW 




Fine. 




48 


2 





47 


53 


30,16 


73 




NW 




Fair. 


24 


3* 


7 





32 


5« 


30,20 


75 




WNW 




Cloudy. 




45 


2 





45 


52 


29,83 


78 




NW 


2 


Cloudy. 


25 


3« 


7 





31 


50 


29,87 


1^ 


0,070 


NW 


2 


Cloudy. 




38 


2 





38 


52 


29,84 


72 




NNW 




Fair. 


26 


28 


7 





29 


49 


30,03 


80 




NW 




Fine. 




4» 


2 





4» 


52 


30,05 


1^ 




NW 




Cloudy. 


27 


39 


7 





40 


50 


29,91 


91 




W 




Cloudy. 




47 


2 





47 


52 


29,92 


82 




NW 




Cloudy. 


28 


37 


7 





37 


50 


29,91 


87 




W 




Cloudy. 




44 


2 





38 


52 


29.93 


80 




NNE 




Cloudy. 


• 29 


29 


7 





29 


49 


29,95 


83 




NNE 


2 


Fine. 




38 


2 





38 


52 


30,01 


77 




NK 


2 


Fair. 



n63 



METEOROLOGICAL JOURNAL 

for March, 1804. 





Six'i 


Time. 


Therm. 


Therm. 


Barom. 


Hy- 


Rain. 


Winds. 






Therm. 






without. 


within. 




gro- 








1804 


leatt and 
greatest 






- 






me- 
ter. 






Weather. 




















Heat. 


H. 


M. 








Inches. 




Inches . 


Points. 


Str. 

I 




Mar. I 



29 


7 





3? 


49 


29,92 




85 




WNW 


Cloudy. 




36 


2 





36 


5« 


29,91 


74 




E 


I 


Fair. 


a 


28 


7 





28 


48 


29,91 


85 




NE 


I 


Fine. 




35 


2 





3* 


50 


29,88 


86 




NE 


2 


Fair. 


3 


29 


7 





3* 


48 


29,65 


78 




W 


I 


Cloudy. 




4' 


2 





38 


50 


29,50 


84 




SE 


1 


Cloudy. 


4 


34 


7 





H 


48 


29,42 


90 


0,085 


ESE 


2 


Cloudy. 




37 


2 





36 


49 


29,40 


90 




E 


2 


Snow. 


5 


36 


7 





39 


48 


*9»35 


88 




E 


Ik 


Cloudy. 




46 


2 





46 


5' 


29,32 


84 




E 


I 


Cloudy. 


6 


39 


7 





39 


48 


29*30 


92 


0,128 


ESE 


I 


Fair. 




46 


2 





46 


5J 


«9'33 


82 




SE 


2 


Cloudy. 


7 


37 


7 





38 


49 


29,58 


91 


0,185 


SSE 


I 


Cloudy. 




50 


2 





50 


S* 


29,68 


81 




SSE I 


Fair. 


8 


37 


7 





37 


. 50 


«9'73 


90 




E I 


Fair. 




5' 


2 





5J 


54 


29,67 


78 




ESE 


2 Fair. 


9 


4S 


7 





46 


52 


29'53 


88 




E 


1 Cloudy. 




5« 


2 





51 


53 


29,47 


9' 




ESE 




Rain. 


10 


45 


7 





45 


^ 


29,76 


95 




S 




Cloudy, 




55 


2 





5+ 


56 


29,82 


9> 




S 




Fine- 


II 


45 


7 





46 


54 


29,78 


96 




E 




Foggy. 




54 


2 





54 


57 


29.7 < 


86 




E 




Fine. 


12 


43 


7 





43 


55 


29,68 


90 




E 




Fine. 




57 


2 





57 


5^ 


29,78 


82 




SE 




Fine. 


13 


46 


7 





47 


56 


29,82 


90 




E 




Cloudy. 




59 


2 





59 


«! 


29,85 


73 




SE 




Fair. 


•4 


44 


7 





44 


56 


29,86 


83 




E 




Fine. 




62 


2 





62 


59 


29,85 


68 




S 


1 


Fine* 


«S 


17 


7 





48 


58 


29,80 


79 




SE 




Cloudy. 




62 


2 





62 


60 


29,75 


68 




S 




Fair. 


16 


45 


7 





45 


58 


29,76 


9> 




SE 




Foggy. 




58 


2 





58 


60 


*9.75 


83 




SE 




Hazy. 



C73 



- 








METEOROLOGICAL JOURNAL 












for March, 1804. 




Six's 


Time. 


Therm. 


Therm. 


Barom. 


Hy- 


Rain. 


Winds. 






Therm. 






without. 


within. 




gro- 








i8o4 


least and 
greatest 












me- 
ter. 






Weather. 




















Heat. 


H. 


M. 








Inches. 




Inches. 


Points. 


Str. 




Mar. 17 


^6 


7 





46 


58 


29,74 




9> 


0,028 


£ 




Cloudy. 




S8 


2 





58 


60 


29,68 


85 




£ 




Cloudy. 


18 


44 


7 





44 


58 


29*55 


92 


o*J3S 


NE 




Rain. 




44 


2 





4> 


59 


29.63 


93 




N£ 




Rain. 


»9 


36 


7 





36 


H 


29,58 


92 


0,238 


N 




Snow. 




40 


2 





39 


S6 


«9'53 


85 




NN£ 




Rain. 


20 


34 


7 





34 


55 


29,58 


86 


0,02 2 


NE 




Cloudy* 




35 


2 





34 


55 


29,66 


83 




NE 


2 


Cloudy. 


21 


3> 


7 





3* 


53 


29.87 


82 




NE 


2 


Cloudy. 




38 


2 





38 


54 


29,89 


76 




NE 


2 


Fine. 


22 


30 


7 





3« 


52 


29,81 


80 




NE 


2 


Cloudy. 




39 


2 





39 


54 


29»74 


72 




ENE 


2 


Fine. 


23 


3* 


7 





32 


52 


29.67 


78 




NE 


2 


Cloudy. 




4» 


2 





4* 


5« 


29,66 


73 




NE 


1 


Fair. 


*4 


33 


7 





^ 


5« 


29,72 


!5 




NW 


I 


Fine. 




46 


2 





54 


29.81 


68 




NW 


I 


Fine. 


*5 


37 


7 





43 


52 


29,61 


79 




SW 


2 


Cloudy. 




49 


2 





48 


54 


29.43 


78 




SW 


2 


Cloudy. 


26 


4« 


7 





44 


5' 


29,27 


9« 


OSO65 


S 


2 


Cloudy. 




50 


2 





SO 


54 


29. > 5 


81 




SSE 


2 


Cloudy. 


27 


36 


7 





39 


5* 


29,22 


89 


0,300 


SSW 


2 


Cloudy. 




49 


2 





47 


55 


29>3» 


71 




SSW 


2 


Cloudy. 


28 


38 


7 





38 


5* 


29»S4 


9> 




NE 


2 


Cloudy. 




44 


2 





43 


S3 


29,64 


86 




NE 


I 


Cloudy. 


29 


33 


7 





35 


5* 


29,78 


87 




NE 


I 


Pair. 




S> 


2 





51 


55 


29,76 


77 




W 


I 


Cloudy. 


30 


45 


7 





47 


5| 


29.63 


89 




W 


I 


Cloudy. 


^ 


56 


2 





55 


56 


29,58 


79 




w 


2 


Cloudy. 


3» 


43 


7 





44 


53 


29,21 


90 


0.353 


w 


I 


Rain. 




49 


2 





49 


56 


29,18 


78 




WNW 


I 


Cloudy. Thiidtf 

there hu been mow, 
hail, rain, and thno- 














'1 • 1 




4er and lightning. 



C^l 









METEOROLOGICAL JOURNAL 










for April, i8o4,. 




Six's 


Time. 


Therm. 


Therm. Barom. 


Hy. 


Rain. 


Winds. 






Therm. 






without. 


within. 




gro- 








1804 


least and 
greatest 












me- 
ter. 






Weather. 




















Heat. 


H. 


M. 








Inches. 



80 


Inches. 


Poinu. 


Str. 




April I 


• 
36 


7 





36 


S3 


29^33 


0.345 


WNW 


2 


Fair. 




45 


2 





44 


55 


29*39 


70 




NW 


2 


Fair. 


2 


35 


7 





37 


5* 


29,29 


81 




WNW 




Cloudy. 




47 


2 





47 


55 


29,22 69 




NE 




Hazy. 


3 


34 


7 





38 


52 


29»35 


87 




NE 




Cloudy. 




48 


2 





47 


54 


29,51 


7« 




NW 




Cloudy. 


4 


36 


7 





39 


5« 


29,67 


85 




W 




Fine. 




52 


2 





50 


55 


29»59 


79 




ssw 


2 


Cloudy. 


5 


38 


7 





40 


5* 


29,49 


83 




ssw 


2 


Cloudy. 


« 


48 


2 





46 


55 


29»47 


77 




w 


2 


Cloudy. 


6 


37 


7 





39 


5» 


30,00 


80 


0,100 


WNW 


I 


Fine. 




52 


2 





51 


55 


30,14 


70 




NW 


2 


Fair. 


7 


41 


7 





4" 


53 


30,25 


78 




NW 




Cloudy. 




53 


2 





53 


56 


30,28 


67 




N 




Cloudy. 


8 


4» 


7 





42 


53 


30.27 


84 




E 




Fine. 




53 


2 

1 





52 


56 


30*24 


65 




E 




Cloudy. 


9 


37 


7 





39 


51 


30,14 


85 




NE 




Cloudy. 




49 


2 





49 


56 


30*03 


76 




NE 




Cloudy. 


10 


4« 


7 





41 


53 


29,89 


90 


0,022 


NE 




Rain. 




45 


2 





45 


55 


29.92 


80 




NE 




Cloudy. 


II 


39 


7 





40 


53 


29,96 


87 


/■ 


NE 


^ 


Cloudy. 




43 


2 





43 


55 


29>95 


82 




NE 




CloLdy. 


12 


39 


7 





41 


53 


29,87 


90 




NE 




Cloudy. 




44 


2 





44 


55 


29,85 


^1 




NE 




Cloudy. 


13 


39 


7 





40 


53 


29*74 


86 




NE 




Cloudy. 




45 


2 





45 


55 


29*72 


80 




ENE 




Cloudy. 


H 


41 


7 





4* 


5| 


29,69 


89 




NE 




Cloudy. 




54 


2 





54 


56 


29,67 


74 




ENE 




Fair. 


>5 


42 


7 





4+ 


54 


29,62 


90 




NE 




Cloudy. 




^l 


2 





58 


57 


29,58 


80 




NE 




Cloudy. 


16 


46 


7 





46 


57 


29,58 


86 




NE 


2 


Cloudy. 




50 


2 





50 


57 


29,58 


80 


NE 1 


2 


Cloudy. 



C93 











METEOROLOGICAL JOURNAL 












for April, 1804. 




Six's 


Time. 


Therm. 


Therm. 


Barom. Hy- 


Rain. 


Winds. 






Therm. 






without. 


within. 


'gro- 








i8q4 


least and 
greatest 










t 


me- 
ter. 








Weather. 




















Heat. 


H. 


M. 





Q 


Inches. 


Inches. 


Points. 


Str. 




Apr. 17 




43 


7 





^ 


ss 


29«6a 




86 




NE 


2 


Cloudy. 




47 


a 





46 


57 


29,62 


86 




NE 


3 


Cloudy. 


18 


41 


7 





4* 


55 


29,70 


88 


0,075 


NE 


3 


Cloudy. 




49 


2 





+! 


56 


a9,77 


73 




NE 


3 


Cloudy. 


'9 


34 


7 





36 


55 


29.87 


81 




N 


2 


Fine. 




47 


a 





4f 


56 


39,80 


7a 




NW 


2 


Cloudy. 


20 


35 


7 





36 


5+ 


39,60 


83 


0,095 


NW 


2 


Cloudy. 




45 


a 





43 


56 


39,67 


82 




NW 


2 


Cloudy. 


21 


36 


7 





37 


54 


39,64 


77 


0,055 


NW 


2 


Fine. 




48 


a 





48 


56 


39,66 


65 




NW 


2 


Hazy. 


aa 


34 


7 





37 


5+ 


39,65 


86 




WNW 


I 


Fine. 




5» 


a 





50 


56 


39,66 


65 




WSW 


I 


Hazy. 


a^3 


35 


7 





4* 


53 


29*55 


90 


o>i55 


SW 


2 


Cloudy. 




49 


a 





47 


57 


39,61 


87 




W 


I 


Rain. 


24 


44 


7 





50 


55 


39,63 


94 


0,390 


S 


2 


Rain. 




58 


a 





58 


57 


^9»^7 


81 




s 


2 


Cloudy. 


*5 


SI 


7 





5» 


s! 


29*5 » 


90 


0,050 


£ 


1 


Cloudy. 




56 


a 





5» 


s! 


a9,44 


84 




S 


2 


Rain. 


26 


47 


7 





^? 


56 


29-45 


87 


0,062 


SSW 


2 


Cloudy. 




58 


a 





58 


59 


29'55 


75 




W 


2 


Cloudy. 


27 


50 


7 





P 


1^ 


29*34 


93 


0,190 


SSW 


2 


Cloudy. 




61 


a 





61 


61 


29*49 


7« 




WSW. 


a 


Fair. 


28 


50 


7 





5« 


$9 


a9,6i 


87 




SSE 




Cloudy. 




60 


a 





60 


60 


39,66 


86 




S 




Rain. 


*9 


5« 


7 





51 


59 


39,88 


90 


0,027 


SSW 




Cloudy. 




66 


a 





66 


61 


39,93 


7» 




SSW 




Fair. 


30 


5* 


7 





53 


fio 


29,90 


88 


0,038 


SSE 




Cloudy. 




7' 


a 





70 


61 


39,86 


75 




SE 




Fair. 



Cio^ 









me'i:eorological journal 


i 






for May, 1S04. 


1 ' 
1 


Six's 


TiirfC. 


Therm. Therm. 


Barom. 


Hy. Rain. 


Winds. 




1 
J 


Therm. 






without. 


within. 




gfO- 








1 

1804 


lean and 












me- 






Wealbcr. 


greatest 










tcr. 1 










Heat. 


H. 


M. 








Inches. 




87 


Inches. 


Points. 


Str. 




May 1 



56 


7 





58 


6z 


29,80 




ESE 


Cloudy. 


^ 


7» . 


2 


D 


70 


63 


29,78 


76 




6W 




Hazy. 


2 


52 


7 


b 


53 


62 


29,92 


86 




SW 




Fine, 




68 


2 





68 


64 


29-93 


7« 




£ 




Fair. 


3 


S3 


7 





53 


6z 


'-^9' 80 


86 




E 


2 


Cloudy. 




7' 


2 





70 


64 


29,82 


77 




SSE 


2 


Fair. 


4 


58 


7 





60 


63 


29,86 


86 




NW 


I 


Cloady. 




71 


2 





70 


64 


29,84 


79 




NNE 




Cloudy. 


5 


56 


7 





58 


!i 


*9.84 


$2 


0,016 


«.NNE 




Cloudy. 


r "^ 


73 


2 





13 


66 


29,98 


70 




ESE 




Fair. 


6 


^8 


7 





60 


^J 


30,17 


88 




SSE 


* 


Cloudy. 




70 


2 





70 


65 


30,20 


75 




SW 




Cloudy. 


7 


58 


7 





61 


55 


30,27 


87 




W 




Cloudy. 




72 


2 





7« 


!^ 


3<5/^7 


73 




(NW 




Fair. 


8 


51 


7 





57 


66 


30,29 


81 




.NE 




Fair. 




65 


2 





6$ 


67 3o,»« 


68 




NE 




Fair. 


9 


SO 


7 





53 


64 


30,12 


81 




NE 




Cloudy. 




67 


a 





67 


65 


29*99 


69 




ssw 


m 


Fair. 


10 


53 


7 





53 


63 


29,91 


87 


0,178 


WNW 




Fair. 




63 


2 





62 


64 


29>93 


67 




NW 




Cloudy. 


11 


49 


7 





50 


63 


29-93 


Bo 




NW 




Fine. 




62 


2 





59 


64 


29*94 


67 




NW 




Cloudy. 


12 


46 


7 





4* 


61 


30,05 


7* 


0,075 


NNW 




Fair. 




58 


2 





57 


62 


30,06 


66 


i 


l^NW 




Fair. 


>3 


44 


7 





47 


61 


30,08 


78 




W 




Fine. 




64 


2 





62 


63 


30,08 


64 




NE 




Fair. 


H 


J? 


7 





5* 


60 


30,05 


74 




£ 




Hazy. 




2 





64 


62 


30.07 


70 




SSW 




Fair. 


15 


so 


7 





53 


61 


30,06 


7J 




SSE 




Cloudy. 




70 


2 





70 


62 


30,02 


68 




S 




Fair. 


16 


S6 


7 





60 


62 


29,88 


77 




SSE 




Cloudy. 




69 


2 





68 


62 


29,78 72 




SE 




Cloudy. 



C "3 



«^ 



METEOROLOGICAL JOURNAL 

for May, 1804. 



1804 



May 17 
18 

»9 

ao 

21 
22 

^3 

26 

27 
28 

29 

30 

3> 



Six's 

Therm. 

least and 

greatest 

Heat. 



53 

67 

54 
68 

5» 

70 

5> 

66 

56 
65 

I! 

5» 

65 

54 

67 

5« 
66 

?; 

54 
66 

48 

64 

53 

68 



Time. 



H. M. 



Therm, 
without, 



7 





53 


2 





67 


7 





54 


2 





66 


7 





56 


2 





68 


7 





57 


2 





69 


7 





5+ 


2 





65 


7 





58 


2 





63 


7 





53 


2 





67 


7 





56 


2 





61 


7 





5« 


2 





«55 


7 





54 


2 





67 


7 





53 


2 





65 


7 





56 


2 





63 


7 





55 


2 





66 


7 


D 


51 


2 





64 


7 


D 


53 


2 


D 


68 



Therm. 

within. 



62 

63 
62 

63 
62 

63 

62 

64 

62 

64 

63 

63 
62 

63 

62 

62 

61 

62 

62 

62 

64 

62 

61 

62 

61 

62 

60 

61 

61 

62 



Barom. 



Inches. 



29.67 
29,78 
30,03 
30,01 
29,86 

29.77 
29,74 

^9'77 
29,83 

29.73 
29.78 

29,85 

30,07 

30,07 

29,80 

29,64 

29,68 

^9'7S 
2^,6j 

29,69 

29,86 

29,90 

29,86 

29,78 

2971 

29,91 

30,10 

30,06 

29.96 

29>99 



b 2 



Hy. 
gro- 
me- 
ter. 



o 
88 

67 
86 

70 

81 

69 

77 

67 

73 

7' 
90 

73 
86 

69 
88 

87 
82 

70 
87 
67 
82 
68 
80 
69 

87 
70 
84 

72 
81 
68 



Rain« 



Inches. 



o»373 



0,033 



Winds. 



Points. 



0,058 



0,047 
O1O9O 



o>333 
0,045 



SW 
W 

ssw 
s 

S£ 

SE 
NNE 

NE 
ENE 

E 

SE 

W 
SSW 

S 

S 

S 
SW 
SW 

S 

S 

S 

S 

S 
SSE 

W 
WNW 

w 

s 

WNW 



Str. 



Weather. 



2 

2 

2 

2 

2 

I 

I 

2 

2 

2 

2 

2 

2 

2 

2 

2 

2 

2 

2 

2 

2 

I 

2 



Fair, 

Fair. 

Cloudy* 

Fair. 

Cloudy. 

Hazy. 

Fair. 

Fair. 

Fair. 

Fair. 

Rain. 

Cloudy. 

Cloudy. 

Fair. 

Rain. 

Rain. 

Fair, 

Fair. 

Fine, 

Hazy. 

Fair, 

Fair. 

Fair. 

Qoudy. 

Cloudy, 

Fair. - 

Fine. 

Fair, 

Fine. 

Fair. 



C 1^ 1 



METEOROLOGICAL JOURNAL 

for June, 1804. 



1804 



June I 

2 

3 

4 
5 



Six's 
Therm, 
least and 
greatest 

Heat. 



7 

8 

9 
10 

11 

12 

>3 

H 

>5 

16 



o 

5' 

70 
53 

56 

79 
60 

81 

60 

61 

71 

69 

5» 
66 

67 

SO 
63 

47 
66 

49 

70 

57 
70 

61 

69 

57 
70 

5* 

70 



T 



Time, 



H. M. 



7 

2 

7 

2 

7 

2 

7 

2 

7 

2 

7 

2 

7 

2 

7 

2 

7 

2 

7 

2 

7 

2 

7 

2 

7 

2 

7 

2 

7 

2 

7 

2 



o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 



Therm, 
without. 



55 
70 

55 
74 
58 
78 
66 

80 
61 

75 

63 
70 

69 

64 

67 

53 
63 

50 
65 

53 

70 

58 
70 

62 

64 

57 
69 

54 
do 



Therm, 
within. 



61 

63 
61 

63 

63 

66 

65 

7» 

67 
68 

67 
68 

66 

68 

^61 

tt 
64 

«+ 
A* 

64 

66 



Barom. 



Inches. 



30* H 
30,14 

30,12 

3o>o6 

30>02 

30>oi 
29,97 
29,94 
30,03 
30.04 
30,02 

«9'94 
29,91 

29^09 
29,68 
29,94 
30,04 
30,12 
30,10 

30,36 
30,38 

.30,40 
30,40 

30,36 

30,31 
30,20 

30,13 
30,00 

29,94 

29,83 

^9,76 



Hy- 
gro- 
me- 
ter. 



o 
82 

67 

li 

81 

61 

76 

72 
81 

72 
82 

73 
80 

68 

78 

70 

77 
66 

82 

82 

• 79 
168 

83 
70 
76 

73 
83 
83 
87 
7a 

84 
78 



Rain. 



Inches . 



0,260 



Winds. 



Points. 



0,262 



wsw 

wsw 

wsw 

ssw 

sw 

s 

E 

s 

w 
wsw 
wsw 

s 

s 
ssw 

sw 

sw 

w 

WNW 

sw 
wsw 

NE 
NE 
NE 
ENE 
ESE 
ESE 

E 

N 
NE 
NE 

E 

E 



Str 



2 
2 
2 
2 
2 
2 
2 



Weather. 



Fair. 

Fair. 

Cloudy. 

Fine. 

Fine. 

Fine, 

Cloudy. 

Fine. 

Cloudy. 

Cloudy. 

Cloudy. 

Cloudy. 

Cloudy. 

Cloudy. 

Cloudy. 

Cloudy. 

Fair. 

Fair. 

Cloudy. 

Cloucfy. 

Fine. 

Fair. 

Fair. 

Fine. 

Cloudy. 

Cloudy. 

Cloudy. 

Rain. 

Fine. 

Cloudy. 

Cloudy. 

Fair. 



C ^3 2 











METEOROLOGICAL JOURNAL 










for June, 1804,. 




Six's 


Time. 


Therm. 


Therm. 


Barom. 


Hy- 


Rain. 


Winds. 






TTierm. 






without. 


within. 




gro- 








1804 


least and 
greatest 












me- 

tcr. 






Weather. 




















Heat. 


H. 


M. 








Inches. 




Inches. 


Points. 


Str. 




June 17 


» 



56 


7 





5« 


64 


29,83 




87 




sw 


Fine. 




7a 


2 





7» 


66 


29,92 


69 




WNW 




Cloudy. 


18 


57 


7 





58 


H 


30,10 


83 




w 




Fine. 




73 


2 





7* 


66 


30,19 


70 




w 




Pine. 


>9 


55 


7 





57 


^3 


30»37 


80 


■ 


sw 




Hazy. 




68 


2 





68 


65 


30,36 


73 




ssw 




Cloudy. 


20 


60 


7 





62 


^5 


3o»34 


83 




sw 


2 


Cloudy. 




76 


2 





75 


68 


3o»33 


72 


1 


WNW 




Fair. 


21 


58 


7 





66 


66 


3o»3^ 


88 




wsw 




Cloudy. 




8ii 


2 





81 


68 


30^3 « 


7> 




ssw 




Fine. 


22 


61 


7 





64 


68 


30.33 


81 




WNW 




Fine. 




7« 


2 





77 


70 


30.30 


70 




NE 




Hazy. 


*3 


56 


7 





58 


68 


30»34 


77 




E 




Fine. 




S8 


2 





68 


68 


30*30 


70 




E 




Pine. 


«4 


56 


7 





60 


63 


30,25 


83 




E 




Fine. 




75 


2 





75 


69 


3o>2i 


66 




E 




Fine. 


*5 


59 


7 





63 


68 


30,18 


79 




ENE 




Fine. 




87 


2 





85 


Z' 


30,17 


63 




SE 




Fair. 


26 


S7 


7 





60 


68 


30,24 


83 




NE 




Cloudy. 




68 


2 





68 


69 


30,20 


75 




E 




Cloudy. 


27 


56 


7 





58 


68 


30,04 


77 




NE 




Fair. 




68 


2 





67 


68 


30,00 


70 




-NE 




Fair. 


28 


49 


7 





53 


67 


30,11 


78 




NE 




Fair. 

ft 




63 


2 





61 


^7 


30,16 


71 




NE 




Cloudy. 


29 


48 


7 





5» 


^5 


30.14 


78 




W 




Fair. 




. 7* 


2 





72 


67 


30,02 


64 




WSW 




Fine. 


30 


54 


7 





56 


66 


29.97 


?7 




WSW 


I - 


Fair. 




74 


2 





74 


67 


29,90 


66 




SW 




Fine. 



ChI 











METEOROLOGICAL JOURNAL 












for July, 1804. 




Six's 


Time. 


ThTcrm; 


TbcTin. 


Bftrom. 


Hy: 


R«itt. 


r 

Windsi 






Therm. 






without. 


within. 




ero- 








IS04 


least and 
greatest 














me- 
ter. 






Weatlier. 




















Heat. 


H. 


M. 








Inches. 




Inchci. 


Foinu. 


Str. 




July 1 




58 


7 





60 


66 


29,81 




73 




SSE 


ff 


Pine^ 




73 


2 





73 


68 


29,82 


67 




ESE 




FinCf 


2 


56 


7 





61 


67 


29,86 


80 




E 




Fain 




7a 


2 





72 


68 


29,80 


67 




E 


\ 


Fain 


3 


57 


7 





62 


67 


29,70 


78 




ENE 




Cloudy. 




65 


2 





65 


68 


29,68 


81 




NW 




Cloudy. 


4 


54 


7 





55 


^s 


29,82 


82 


0,032 


NW 


2 


Fine. 




7> 


2 





7« 


67 


29.85 


63 




NW 


1 • 


Fine. 


5 


5S 


7 





56 


63 


29,82 


79 




8W 




RaiiK 




65 


2 





65 


^5 


29^75 


72 




SSE 




Cloucfy. 


6 


54 


7 





55 


^5 


29J71 


90 


0,200 


NE 




Rain. 




63 


2 





63 


^5 


29,83 


8J 




ESE 




Cloody. 


7 


57 


7 





60 


^5 


29,83 


90 


0,075 


SE 




Cloudy. 




63 


2 





6z 


f5 


29^75 


90 




S 




Rain.. 


8 


56 


7 





58 


^J 


29,68 


90 


0,415 


SW 




Pair. 




7» 


2 





7« 


66 


29,68 


71 


w 


sw 




Pair, 


9 


55 


7 





57 


^1 


29,78 


8'7 


0,105 


WSW 


• 


Cloudy. 




73 


2 





73 


66 


29.?7 


71 




SW 




Fain 


10 


1* 


7 





58 


^s 


29»74 


86 


0,035 


E 


« 


Rain* 




62 


2 





62 


65 


29,64 


94 




E 


* 1 


Rain. 


11 


5« 


7 





53 


64 


29,98 


8i 


2,09b 


NNE 




Pine. 




60 


2 





60 


64 


30,11 


67 




NE 




Cloady. 


12 


5° 


7 





il 


63 


30,23 


7« 




N 




Cloudy. 




64 


2 





^ 


30,21 


64 




N 


• 1 


Cloudy. 


13 


49 


7 





53 


63 


30,21 


n 




Nfi 




Fair. 




68 


2 





68 


65 


30, i 7 


63 


> 


NE 


\ 


Fair. , 


14 


53 


7 





57 


62 


30,1^ 


78 




E 


1 


Cloudy. 




66 


2 





66 


64 


30,10 


69 




E 


I < 


Cloudy. 


15 


5' 


7 





53 


63 


30,08 


8-2 




E 




Pine. 


^ 


73 


2 


c 


7» 


65 


50,04 


65 


■ 


ENft 




Fine. 


16 


58 


7 





60 


64 


30,11 


80 




NE- 




Pine. 




78 


Is 


6 


77 


67. 


3013 


62 




NE 


£ 


Pine. 



t:»5:3 







METEQROLCKJJCAL JOURNAL 

for July, 1804. 


Six'i 


Time. 


Therm, 


■ 

Tbprm. 


.B.arom. 


Hy. 


lUiui* 


Winds. 






Therm. 






withqut. 


within. 




geo- 








i8o4 


lejutand 
greatest 












me- 
ter. 






Weather. 


















Heat. 


H. 


M. 








iitfhcs. 




78 


Inches. 


Points*. 


Str. 


• 


July 17 


it 







■64 


66 


30aU 


( 


wsw 


Fair. 




80 







79 


68 


30,0$ 


63 




s 




Fiue. 


iB 


63 







.68 


68 


29,83 


71 


, 


sw 




Cloudy. 




75 







74 


69 


29,76 


68 




^sw 




Cloudy. 


>9 


.61 







61 


67 


29,57 


83 


0,062 


ssw 




Rain. 




74 







7» 


69 


29-55 


68 




wsw 




Fair. 


20 


58 







61 


67 


29.65 


77 


0,190 


NB 




Fair. 




67 







63 


67 


29.7.2 


83 




NE 




Cloudy. 


21 


• 5< 







58 


66 


29,79 


83 




NNE 




Cloudy. 




67 







67 


63 


29,85 


70 




NE 




Fair. 


22 


55 







58 


66 


29>73 


78 




E 




Cloudy, 




69 







67 


^^ 


29^53 


78 




SSW 




Cloudy, 


23 


55 







57 


66 


29,4.4 


81 


0,053 


SSE 




Fair. 




68 







67 


66 


29*^4 
29,62. 


73 




SSE 




Fair. 


«4 


57 







60 


66 


&o 




.ENK 




Clpudy. 




73 







70 


67 


29*64- 


66 




NW 




Cloudy. 


as 


56 







57 


64 


29,61 


175- 




WNW 




Cloudy. 




71 







7' 


^^ 


29*54 


63 




WNW 




Fair. 


26 


58 







60 


66 


29,44 


00 


0,390 


NE 




R^n. 




• 70 







70 


67 


29*51 


66 




NE 




Fair. 


a? 


55 







57 


66 


29,54 


81 




SW 




Fine. 




66 







66 


66 


29^48 


73 




S 




Cloudy. 


28 


H 







57 


^1 


29,50 


Hi 


0,942 


s 




Fair. 




. 68 







67 


66 


29iSS 


■73 




s 




Fair. 


»9 


57 







5« 


65 


2.9,65 


79 




s 




Fair. 




•7« 







72 67 


29,76 


69 




iT 




Fair. 

« 


30 


55 







56 


fs 


30,03 


83 


0,916 


s 




Cloudy. 




76 







75 


68 


30*05 


66 




WSW 




Fine. 


31 


$8 







59 


^s 


30,20 


75 




w 




i?ine. 




7« 


- 





77 


69 


30,20 


60 

1 




W I 


Fine. 



cis:] 



METEOROLOGICAL JOURNAL 

for August, 1804. 





Six's 


Time. 


Therm. 


Therm, 


Barom; 


Hy. 


Rain. 


1 

Winds. . 






Therm. 






without. 


within. 




gro- 








1804 


least and 
greatest 












me- 
ter. 






Weather. 




















Heat. 


H. 


M. 








Inches. 




Inchei. 


Pointa. 


Str. 




Aug. 1 




68 


/ 





70 


69 


3o;27 




78 




NB 


1 

I 


Cloudy. 




79 







79 


It 


30,27 


67 




NB 


1 


Cloudy. 


2 


61 







62 


30,16 


78 




N£ 


1 


Cloudy. 




7' 







7« 


69 


30>o6 


75 




NE 


I 


Cloudy. 


3 


61 







63 


68 


29,92 


9' 




NE 


1 


Cloudy. 




81 







81 


70 


29,83 


74 




ENR 


I 


Fair. 


4 


64 







65 


69 


29,78 


87 




NNW 


I 


Cloudy. 




7+ 


• 





7* 


70 


2976 


78 




NW 


I 


Cloudy. 


5 


57 







61 


69 


29.84 


84 


0,090 


W 


I 


Cloudy. 




74 







73 


70 


29,81 


67 




SSW 


2 


Fair. 


6 


S8 


M 





59 


66 


29,91 


80 


• 


wsw 


a 


Pair« 




73 







7* 


69 


29,98 


62 




WNW 


I 


Fair. 


7 


53 







54 


67 


30,10 


78 




W 


I 


Fair. 




7» 







7' 


68 


30»" 


63 




NW 


z 


Fair. 


8 


58 







58 


65 


29,6s 


86 


0,300 


S 


a 


Raiiu 




73 







73 


68 


29.55 


67 




w 


a 


Fair. 


9 


54 







55 


67 


29,86 


79 




wsw 




Fair. 




73 







7* 


68 


29,81 


65 




s 




Cloudy. 


10 


58 







58 


65 


29,56 


80 




s 




Fair. 




70 







69 


67 


29,66 


7" 




_ 

w 




Cloudy. 


II 


55 







56 


66 


30,00 


78 




SSW 




Fine. 




70 







70 


66 


29,01 


65 




sw 




Cloudy. 


12 


57 




O' 


57 


!l 


29,70 


80 


0,016 


s 




Cloudy. 




65 







63 


66 


29,62 


71 




8 




Cloudy. 


»3 


53 







56 


^5 


29,61 


80 


0,072 


s 




Cloudy. 




63 







57 


^+ 


29,18 


93 




E 




Rain. 


14 


49 







50 


63 


*9*47 


55 


0,880 


W 




Fine. 




70 







70 


65 


29.53 


65 




S 




Fair. 


>5 


54 







55 


63 


29,58 


88 




S 




Cloudy. 




7« 







7« 


g 


29>S7 


77 




SSW 




Cloudy* 


16 


57 







57 


29.57 


91 


1*030 


SSW 


I 


Rain. 




69 


2 





68 


66 


29,64 1 72 




WSW 


2 


Fair. 



I 



Ci7 3 







METEOROLOGICAL JOURNAL 






for August, 1804,. 




Six't 


Time. 


Therm. 


Therm. 


Barom* 


Hy. 


Rain. 


Winda. 






Therm* 
least and 




without. 


within. 




gro- 








1804 


greatest 










me> 
ter. 






—— 


Weather. 
















Heat. 


H. M. 


e 


o 


Inches. 




Inchei. 


Points. 


Str. 




Aug. 1 7 




54 


7 


55 


64 


29*80 




83 


0,075 


wsw 


2 


Cloudy. 




68 


2 


«4 


65 


29,87 


73 




wsw 


2 


Fair. 


18 


50 


7 


5* 


63 


30»oo 


80 


0,135 


sw 




Rain. 




63 


2 


62 


64 


29,92 


73 




w 




Cloudy. 


«9 


54 


7 


55 


63 


29,77 


!♦ 


0,110 


NE 




Cloudy. 




67 


2 


65 


64 


29,80 


69 




N 




Cloudy. 


20 


51 


7 


I* 


62 


29,87 


82 




W 




Cloudy. 




64 


2 


64 


63 


29,88 


71 




NW 




Cloudy. 


SI 


53 


7 


54 


62 


29,92 


83 




W 




Cloudy. 




63 


2 


62 


63 


29.94 


7* 




NW 




Cloudy. 


22 


56 


7 


I** 


62 


29.97 


77 




N£ 




Cloudy. 




66 


2 


66 


64 


30,00 


66 




NB 




Fair. 


»3 


54 


7 


54 


62 


30»" 


78 




N 




Cloudy, 




63 


2 


63 


63 


30,13 


7? 




NE 




Cloudy. 


»4 


1^ 


7 


55 


62 


30.17 


7j 




W 




Cloudy, 




2 


66 


63 


30,17 


67 




WNW 




Cloudy. 


»5 


53 


7 


55 


62 


30,14 


80 




N 




Cloudy. 




J 


2 


P 


63 


30,17 


68 




NNE 




Cloudy. 


26 


7 


62 


30,28 


77 




NE 




Cloudy. 




67 


2 


66 


63 


30,30 


68 




NE 




Fair. 


«7 


S* 


7 


S* 


62 


30,2A 

30,16 


^' 




SW 




Fine. 




71 


2 


70 


64 


65 




W 




Fair. 


28 


59 


7 


60 


63 


30.17 


83 




WSW 




Cloudy. 




72 


2 


7* 


65 


30,19 


7» 




WSW 




Fair. 


29 58 


7 


58 


^5 


30.17 


85 




sw 




Fine. 


77 


2 


?5 


67 


30,12 


7« 




s 




Fine. 


30 63 


7 


64 


^7 


29,90 


88 


0,093 


NE 




Fair. 




80 


2 


80 


69 


29,89 


75 




s 




Fine. 


3> 


63 


7 


63 


68. 


30,07 


80 




NE 




Fair. 




73 

• 


2 


7* 


69 


30*09 


73 




NE 




Cloudy. 



t»o 



MEtEOROtOGIGAL JOUkfjAt 

for Se^tehlBeri 1B04. 


1804 


Six's 

Therm. 

least and 

greatest 

Heat. 


Time. 


Therm, 
without 


Tlifcnn. 
within. 


fitr<nn. 


Ity- 
gro- 
me- 
ler, 



76 
63 

8d 

67 
81 

SI 

68 

85 
68 

82 

68 
60 
70 
82 

!l 

?8 

83 

70 

86 

83 
73 
9» 


Rain. 


Iftrindi. 


Wodie^. 


H. Al« 


< 







Inchet. 

36iOO 
30,10 

30i20 

30,18 

30^21 
30,28 

30>3» 
30,30 

30,»7 

30,13 
30,02 

*9*94 

*9'97 
30,16 

30,20 

30,42 

30,1$ 
30,0b 
39,98 

30,14 
30,17 
30,18 
30,12 
30,0© 
30,00 
30,02 
29,92 
29,96 
29,96 
30,01 
j0,07 


lochei. 


Pdinta. - 


Str; 

2 

2 
2 


Sept. I 

2 

3 

4 

5 

6 

7 
8 

9 
to 

II 
12 

»3 
»4 

«5 

16 

1 




68 

?l 

73 
57 
7* 
55 

7* 

53 
70 

54 
70 

5» 

74 

69 
55 

62 
81 
62 

79 
63 

62 


7 
2 

7 

2 

7 
2 

7 
2 

7 
2 

7 

2 

7 
2 

7 
2 

7 
2 

7 
2 

7 
2 

7 

2 0! 
7 0! 
2 0' 

7 
2 

7 

t 

7 
2 


58 

68 

58 
73 
58 

5f 

7* 

55 

70 

55 

70 

55 

74 

li 

64 
81 ' 
62 

64 

78 

63 
81 


66 
68 

67 
68 

67 
66 

67 
68 

65 

70 

69 
68 
69 
66 

68 ' 

69 , 
68 

72 

70 

11 

73 

70 

73 
70 




w 

wKw 
sw 
sw 
sw 
ssw 
sw 
ssw 

WNW 

s 

NE' 

ENE 
E 

sw 

W 

S 
ENE 

E 
NE 

S 

SW 
SSW 
SW 
SSE 

TS 
S 

9E 

6 

^ 

NE 
E 


Flnei 
Fine. 
Fine^ 
Fdn 
Fine» 

aoddy. 

Cloudy. 

Cloudjr. 

Fain 

Cloiidy. 

Fain 

Fine. 

Finek 

Faifi 

Fain 

Fine; 

Fine. 

Pine. 

Fine. 

Cloudy* 

Fain 

Fidn 

FInet 

Fine. 

Fine; 

Fine. 

Cloudy. 

Fine. 

Clouiy. 

Fine^ 

Cloudy. 

Fine. 






C»»D 



• 






UETUQtiOhQQlCAh JOUENAJU 

for Septeinilier, 180^1. 




SU'i Time. 


Tfa^rm. 


Tbenn* 


»»n»P»' 


Hy- 


Kaiii. 


Winds. 






Therm. 




without. 


withm. 




gTO- 








1804 


least and 
greatest 












me* 
ter. 






Weather. 






• 






- 


■ 


' 




Heat. 


H. 


M. 








Inch^. 




Inches. 


Points. 


6tr. 




Sep. 17 


^3 


7 





Ss 


72 


30>l8 




88 




NE 


1 


Cloudy. 




67 


2 





70 


30,18 


83 




NE 


2 


Cloudy. 


18 


S9 


7 





60 


70 


30,18 


81 


• 


NE 


2 


Cloudy. 




63 


2 





<» 


69 


30,20 


78 




NE 




Cloudy. 


»9 


^S 


7 





59 


69 


30'.« « 


80 




ENE 




Cloudy. 




68 


2 





6S 


68 


30*07 


74 


- 


S 




Fair. 


20 


6t 


7 





6x 


68 


30,10 


84 




wsw 




Cloudy. 




7« 


2 





70 


70 


30,oiJ 


66 




NW 




Fine. 


21 


S* 


7 





55 


68 


Jo,io 


79 




WNW 




Cloudy, 




66 


2 





,65 


68 


30,05 


66 




W 




pair. 


22 


5° 


7 





5* 


66 


30,14 


V^ 




WSW 




[Cloudy. 




63 , 


2 





6} 


65 


29>q8 


69 




wsw 


1 


Cloudy. 


23 


49 


7 





5° 


65 


?9»58 


76 




WNW 




Cloudy. . 




59 


2 





58 


64 


?9'96 


65 




NNW 


2 


Fair. 


*4 


4« 


7 





50 


63 


30,02 


78 




NfJW 


I 


Cloudy. 




59 


2 





57 


63 


30,05 


70 




N 


2 


Cloudy. 


»S 


If 


7 





5* 


62 


30* « 8 


84 




NE 


2 


Cloudy. 




2 





61 


63 


30.20 
30,46 


70 




NE 


2 


Fair. 


26 


45 


7 





47 


61 


80 




NE 


2 


Fine. 




59 


2 





5! 


63 


3o>47 


70 




NE 




Fine. 


a? 


49 


7 





f* 


61 


30*37 


84 




NE 




Cloudy. 




62 


2 





j62 


62 


30,34 


77 




NE 




Cloudy. 


28 


53 


7 





53 


61 


30,34 


88 




NE 




Cloudy. 




60 


2 





60 


62 


30,32 


68 




NE 




Cloudy. 


*9 


5« 


7 





5* 


61 


30,27 


88 




NE 




Cloudy, 




59 


? 





59 


61 


30,18" 


83 




£ 




Cloudy. 


30 


t 


7 





i: 


60 


30,00 


87 




£ 


M 


Foggy. 




2 





61 


29,92 


84 




£ 

• 




M^n. 



C 2 



Cao^ 











METEOROLOGICAL JOURNAL 

for October, 1804. 




Six'i 


Time. 


Therm. 


Therm. 


Barom. 


Hy- 


Rain. 


' Winds. 


. 




Therm. 






without. 


within. 




gro- 








1804 


leaic and 
greatett 












mc« 
ter. 






Wettherw 




















Heat. 


H. 


M. 








Inches. 




90 


Inchett 


Poinu. 


Str. 




Oct. 1 




57 


7 





57 


60 


«9»77 


a,077 


ESE 


Rain. 




64 


2 





64 


61 


29,76 


87 




NE 




Cloudf. 


2 


53 


7 





53 


60 


29,89 


92 


0i045 


SW 




Cloudy. 




64 


2 





64 


62 


29,96 


86 




SW 




Cloudy. 


3 


57 


7 





59 


61 


29,96* 


94 




S 




Cloudy. 




68 


2 





68 


63 


29,89 


74 




s 




Fair. 


4 


S» 


7 





s;« 


62 


29'97 


90 




s 




Foggy. 




63 


2 





62 


63 


29,92 


77 




s 




Fine. 


5 


57 


7 





57 


62 


a9»57 


92 


0,142 


&w 


1 


Cloudy« 




63 


2 





62 


63 


29,72 


69 




w 




Fak. 


6 


45 


7 





45 


61 


30.«4 


83 




SW 




Fine. 




63 


2 





63 


63 


30,16 


70 




SW 




Fair. 


7 


56 


7 





57 


62 


30,03 


90 




SW 




Cbudy. 




61 


2 





61 


62 


29,90 


80 




s 




Cloudy, 


8 


46 


7 





47 


60 


«9>77 


85 


0,045 


SW 




Fine* 




59 


2 





58 


61 


29,76 


70 




w 




Fair. 


9 


?i 


7 





n 


59 


29.84 


83 




WNW 




Fine. 




2 





61 


29,95 


68 




NW 




Fair. 


10 


38 


7 





40 


58 


3o>"3 


82 




W 




Fair. 




58 


2 





56 


60 


30,02 


77 




S 




Rain. 


11 


|3 


7 





1* 


l^ 


29,52 


95 


o'>345 


SSW 




Radn. 




61 


2 





61 


61 


29,38 


§5 




s 




Cloudy. 


12 


44 


7 





46 


|5> 


29>37 


86 


0,350 


SW 




Fair. 




55 


2 





54 


60 


29,29 


77 




SW 




Rain. 


>3 


38 


7 





38 


1^ 


29,46 


85 


0,037 


w 




Cloudy. 




S« 


2 





5« 


60 


29,52 


78 




w 




Fair. 


H 


44 


7 





5* 


1* 


29,27 


95 


0,023 


S 




Rain. 




58 


2 





58 


60 


29,27 


7S 




SW 




Cloudy. 


«S 


48 


7 





48 


1^ 


29.25 


86 


0,048 


SW 




Fair. 




55 


2 





55 


61 


29.33 


68 




wsw 




Fine. 


16 


39 


7 





39 


57 


29,61 


84 




wsw 




Fine. 




54 


2 





S+-, 


61 


^9ilL 


70 




wsw 




Fine. L 



n«o 



tm 



METEOROLOGICAL JOURNAL 

for October, 1804. 



1804 



Oct. 17 

18 

20 

21 
22 

«4 

*5 
26 

a; 

28 

29 
30 

3> 



Six's 

Therm. 

least and 

greatest 

Heat. 



o 

60 
t 

11 

5+ 

59 

56 

4+ 

53 

45 

53 

49 
60 

50 
54 
43 
55 
49 
52 
50 
55 

1^ 
00 



Time. 



n» m* 



7 





2 





































b 






































































































2 






Therm, 
without. 



K 



48 

59 

t 

64 

It 
56 
57 

4' 

56 

44 

5» 
46 

53 
50 
58 

50 
53 
44 
55 
49 
5» 
50 
55 

1: 



Therm, 
within. 



& 

58 
59 

pi? 

I? 
60 

6z 
61 
62 
60 
62 
60 
62 
60 
60 

61 

I' 

60 

61 

II 
I? 



Barom* 



Inches. 



29,67 
29,66 
29,97 
29,96 
30,01 
29*96 
29,85 
29,88 

*9'77 
29,66 

29'43 
29,41 

*9»57 
29,61 

29,77 

29,78 

29,80 

29,78 

29,76 

29,78 

29,76 

29»74 
29,68 

29,62 

29»55 
29,52 

29,30 

29,18 

29,38 

*9»S5 



Hy. 

gro- 
me- 
ter. 



o 
88 

72 
84 

78 
90 

76 

86 
82 

9» 
81 

87 
84 

77 

83 

83 

83 
82 

89 
81 

93 

87 
90 

80 

90 

90 

90 

80 

81 



Rain. 



Inches. 



0,030 

0,063 



Winds. 



Points. 



a,072 



0,290 



0,330 



0^22 



0,042 
0,085 



ssw 
ssw 
sw 

WNW 
SSW 

s 
s 
s 

E 

E 

E 

S 
SW 
NE 
NNE 
NE 
NE 
NE 

£ 
SE 

E 
S£ 

£ 
£SE 

£ 

E 
ENE 

£ 

S 

S 



Str. 



2 

2 
2 
£ 
2 
2 
2 
2 



Weather. 



n • rLightning with 
rair. |_ Uioadcr. 

Cloudy, 

Cloudy. 

Cloudy. 

Cloudy. 

Fair. 

Fair. 

Fair. 

Cloudy. 

Cloudy. 

Cloudy. 

Rain* ^^AuiormBo- 
— , . rcftlitWMvlnble 

rair. from 6^09? M; 

Rair *' timei, it wm 
^. ▼•ry brllliABt, 
Fine, buthadaotmach 

Fine. 

Cloudy. 

Cloudy. 

Fine. . 

Cloudy. 

Rain. 

Rain. 

Foggy, 

Fair. 

Cloudy. 

Rain« 

Fair. 

Cloudy. 

Fair. 

Fair. 



c»o 









MBTeOROLQOICAL JOUKNAL 










for November, 1804,. 




Six't 


Time. 


llterm. 


Therm. 


fiUDIB. 


Hy. 


RttD* 


Wiadt. 




1804 


Therm, 
greatett 






without. 


witlun. 




gro- 






W«idicr. 




















Heat. 


H. 


M. 








Inches. 




Incfaea. 


Pbinu. 


Str. 

1 




Nor. I 


^ 







49 


59 


*9'5S 



90 


o»5>S 


5 


Fine. 




59 







58 


61 


29,60 


82 




8W 


I 


Cloudy. 


2 


5' 







51 


60 


2973 


90 




« 




Rain. 




56 







56 


62 


29,83 


88 




NE 




Qoudy. 


3 


47 







47 


I'' 


30.23 


85 


•*"33 


N£ 




CloiM^. 




49 







48 


61 


30,27 


73 




N£ 




Fane. 


4 


4» 







4* 


58 


30,15 


77 




N£ 




Cloudy. 




45 







44 


59 


30,03 


77 




N£ 




Fair. 


5 


40 
45 









40 
45 


57 
57 


29,90 
29,90 


80 

n 




N£ 
N£ 




Uoudy.r»f««hwi-i 


6 


3« 







38 


55 


^9,98 


77 




ENE 




Cloudy. 




4« 







4a 


56 


29,98 


74 




ENE 




Cloudy. 


7 


38 







39 


54 


29,90 
29,81 


77 




ESE 




<4oudy. 




46 







46 


55 


7« 




6£ 




Cloudy, 


8 


45 







49 


55 


29,53 


92 


0,063 


S£ 




Rain. 




54 







S» 


s^ 


29,41 


88 




ESE 




Cloudy. 


9 


4* 







4» 


56 


29,38 


92 




ESE 




foggy. 




5a 







52 


57 


29.43 


91 




ESE 




Foggr. 


10 


49 







50 


57 


29*24 


93 


0,160 


ESE 




Rain. 




5« 







57 


59 


29,22 


9' 




SW 




Rain. 


11 


5* 







S» 


5« 


»9»25 


94 


0,560 


N£ 




Rain.- 




5a 







5« 


59 


29*37 


94 




NE 




Rain. 


12 


47 







^l 


57 


29.94 


92 


o,jio 


ENE 




Rain. 




56 







56 


59 


29,96 


89 




$ 




Cloudy. 


>3 


5» 







5* 


58 


29,70 


92 


o,too 


^E 




Rain. 




59 







59 


60 


29,66 


93 




SSW 




Cloudy. 


»4 


5« 







53 


5« 


»9o7 


94 


0.093 


^ 




Rain. 




54 







54 


60 


29>SS 


94 




S 




Rain. 


>S 


45 







♦1 


58 


29,78 


9> 


0,37s 


NE 




Cloudy. 
Cloudy. 


_^ 


46 




•0 


46 


59 


29>«4 


89 




NE 




16 


44 


7 





44 


58 


29,98 


92 




NE 




Cloudy. 




-J»- 


2 





48 


.,f8 


30,00 


liaj 




NE 




Rain. 



C*d 3 





AfBTEOROLOGICAL jOURNAt. 




fof Kovember, 1864,4 

. . _ .i . ._ ^ _ ^ 1 ^ . 




Six'* 


Time. 


Therxti. 


irh^m.' 


Barom. 7Iy- 


Rain. ! 


Winas. 






Therm 




without. 


within. 


gro- 


1 






1 8(54 


Itaitand 
greatest 




• 






ne>- 


* 




Weather. 


. ' 








»er. 




3 




Heat. 


Il< m. 


.0 





Inchcs. 




losbet.. 


PoinU. 


Su. 


• 


Nov. 17 


45 


>'« 


46 


57 


• 

30,09 


* 




£ 


• 

I 


Cloudy. 




50 


2 « 


♦? 


59 


30*12 


86 




£ 


1 


Pair. 


18 


45 


7 « 


46 


57 


30,18 


90 




£ 


1 


Cloudy. 




5* 


2 « 


s» 


59 


30, ro 


88 




SE 


I 


Cloudy. 


»9 


48 


7 


5> 


57 


30*1^ 


93 




S 


2 


Cloudy. 




S3 


2 


53 


60 


a9'94 


93 




S 


1 


Rain. 


to 


-H . 


7 6 


44 


57 


30**3 


<n 


0,56+ 


SW 


I 


Cloudy. 




55 


2 « 


50 


60 


30*05 


86 




S 


I 


Pair. 


31 


48 


7 • 


53 


l^ 


29,50 


as 


0,275 


WSW 


2 


Cloudy. 




ft 

S3 


2 


5' 


60 


39.76 


73 




w 


2 


Pair. 


22 


44 


7 


45 


57 


39.76 


86 




w 


I 


Pine. 




4« 


2 d 


♦« 


58 


39,89 


73 




NW 


I 


Pair. 


*3 


38 


7 


4* 


57 , 


29,97 


25 




WSW 


I 


Cloudy. 




50 


2 


50 


5! 


39,84 


85 




SW 


I 


Raia. ; 


a4 


39 


70 


39 


56 


39.85 


87 


6,235 


ENE, 


I 


Raia. 




39 ,, 


2 


37 


57 


39,80 


93 




,NB 


I 


Raia. 


as 


36 


7 «* 


43 


55 


39.84 


81 


Jtl,5io 


. E 


2 


Raia. 




44 


« » 


44 


56 


29,89 


76 




E 


2 


Cloudy. 


s6 


35 


7 


37 


5| 


30.04 


So 




NB 


2 


Cloudy. 1 




44 


2 4 


44 


56 


30,08 


8b 




NB 


I 


Pair. ; 


»7 


35 


7* 


36 


s* 


30,00 


9« 




NB 


1 


Cloudy. 




4« 


2 4 


♦« 


55 


30.05 


77 




NB 


I 


Pair. 


28 


ir 


70 


H 


5* 


30,02 


77 




£NE 


2 


Cloudy. 




2 


.36 


5i 


29 98 


78 




ENE 


2 


Cloudy. 


*9 


3* . 


7 <» 


35 


5« 


39.98 


88 




NE 


I 


Cloudy. { 




3« 


2 


98 


53 


29.97 


^3 




N£ 


I 


Cloudy. 1 


30 


34 


7 


34 


so 


29.9s 


82 




NE 


I 


Pair. 




4*' 

1 


2 


4» 

t 


5> 


5^9,96 

• 


»i 




NE 


I 


Cloudy. 

1 




'J 


— 




♦ 




• 











C«4 3 



i • 


METEOROLOGICAL JOURNAL 


( 


for December, 1804. 




Six'i 


T^me. 


Thenn. 


Therm. 


■ 

Barom. 


Hy- 


R«a. 


Windf. 


- 




Therm. 




without. 


within. 




gro- 




• 




1804 


leait and 
greateat 










me- 
ter. 






Weather, 




. 


, 










1 


Hett. 


H. M. 








Incbei. 




Inches* 


Points. 


Str. 




Dec. I 




35 


8 

• 


1 

35 


so 


a9»96 




90 




NE 




Cloudj. 




4* 


2 


42 


S3 


30,05 


83 




NE 




Cloudy. 


2 


35 


8 


35 


SO 


30,28 


90 




NE 




Cloudy. 




39 


2 


38 


S3 


30,30 


88 




N£ 




Cloudy. 


3 


36 


8 


37 


S> 


30,33 


86 




E 




Cloudy. 




38 


2 


37, 


53 


30,31 


80 




£ 


- 


Fine. 


4 


28 


8 


*9 


49 


29,98 


84 




£ 




Fine. 




39 


2 


39 


5» 


29,78 


83 




£ 




Cloudy. 


5 


39 


8 


45 


5» 


29'33 


93 


0,035 


£ 




Foggy. 


. 


48 


2 


48 


$3 


29,08 


94 




£ 




Cloudy. 


6 


37 


8 


37 


5» 


29,05 


95 




S 




Foggy. 




4' 


2 


41 


53 


29,11 


94 




S 




Foggy- 


7 


38 


8 


43 


5* 


29'43 


94 




NNfi 




Cloudy. 




45 


2 


45 


54 


29,54 


9' 




NNE 




Clouc^. 


8 


43 


8 


43 


5* 


29,83 


93 




N£ 




Cloudy. 




45 


2 


45 


$4 


29,90 


90 




£NE 




Cloudy. 


9 


40 


8 


40 


S* 


29,88 


90 




£ 


I 


Fair. 




45 


2 jP 


45 


53 


29,86 


90 




SE 




Rain. 


10 


40 


8 x> 


40 


S3 


*9'94 


94 


0,093 






Fogfir. 




47 


2 


47 


54 


29,92 


94 




S 




Cloudy. 


11 


44 


8 


44 


53 


29,78 


94 




S 




Fair. 




SO 


2 


SO 


55 


29>7i 


93 




S 




Cloudy. 


12 


4* 


8 


4> 


53 


^9>S^ 


9a 


0,112 


SSW 




Fine, 


t 


5> 


2 


47 


55 


29,50 


88 


1 


S 




Cloudy. 


«3 


4« 


8 p 


46 


5| 


29,06 


90 


0,030 


S 




Fair: fM^'^Jri?* 
Fine. L !«'-•»«. 




48 


2 


48 


56 


29,07 


!3 




S 




H 


44 


8 


44 


54 


*9>3i 


83 


0,030 


WSW 




Fair. 




48 


2 


48 


5<» 


29*49 


8q 




WNW 




Fair. 


«S 


4* 


8 


43 


5+ 


29,78 


83 




WNW 


2 


Cloudy. 




47 


2 


47 


58 


29,92 


81 


1 


NW 


2 


Fine. 


16 


35 


8 


35 


S3 


30,10 


87 




N 




Fine. 




4« 


> 


-11^ 


St. 


30,10 


8? 


1 


NNW 




Qoudy. 



n«5D 











METEOROLOGICAL JOURNAL 












for December, 1804. 




Six's 


Time. 


Therm. 


Therm. 


Barom. 


Hy- 


Rain. 


Winds. 






Therm. 






without. 


within. 




gro- 








1804 


least and 
greatest 












me- 
ter. 






Weather. 




"^^^ 
















Heat. 


H. 


M, 








Inches. 




Inches. 


Pointt. 


Str. 




Dec. 17 




3« 


8 





3« 


5« 


29,95 


• 

83 




NE 


1 


Pair. 


* 


35 


2 





35 


55 


29,96 


83 




N£ 


2 


Fair. 


18 


31 


8 





3« 


5« 


3o>i5 


87 




NE 


2 


Cloudy. 




37 


2 





37 


54 


30.2I 


84 




NE 


2 


Fair. 


»9 


*9 


8 





29 


49 


30,39 


87 




ENE 


2 


Snow. 




3« 


2 





30 


5« 


30,40 


84 




NE 


2 


Snow. 


20 


28 
3« 


8 

2 






88 

30 


48 


30'«5 
30,18 


82 
79 


' 


ENE 

ENE 


2 


Cloudy. fM-fri;^ 


21 


26 


8 





38 


^ 


30,04 


8s 




NE 




Fine. 




35 


2 





35 


s? 


30,02 


81 




NE 




Fine* 


22 


33 


8 





34 


46 


29,84 


li 




NNE 


^ 


Cloudy. 




35 


2 





35 


^ 


29,60 


82 




NNE 


m 


Cloudy. 


23 


29 


8 





3« 


4^ 


*9'S7 


88 




ENE 




Snow. 




35 


2 





35 


48 


29,6x 
29,76 


90 




S 




Cloudy. 


«4 


>9 


8 





20 


44 


88 




E 




Fair. 




3» 


2 





30 


47 


29,72 


88 




NE 




Fair. 


*5 


*2 


8 





^1 


45 


29,63 


90 




NE 




Cloudy. 




38 


2 





38 


47 


»9>55 


9« 




£ 




Cloudy. 


26 


35 


8 





35 


45 


*9»47 


93 


0,130 


E 




Cloudy. 




37 


2 





37 


48 


»9»47 


93 




NE 




Cloudy. 


^7 


33 


8 





34 


45 


*9*55 


9* 


o»075 


NE 




Cloudy. 




37 


2 





37 


48 


29,60 


90 




NE 




Cloudy. 


28 


34 


8 





34 


45 


29,69 


84 




NE 




Cloudy. 




35 


2 





34 


48 


29,68 


82 




NE 




Clou<ty. 


29 


3» 


8 





3« 


45 


29,80 


80 




NE 




Cloudy. 




34 


2 





33 


47 


29,96 


77 




NE 




Cloudy. 


so 


*7 


8 





*7 


44 


30,18 


81 




NE 




Pine. 




32 


2 





3* 


47 . 


30,16 


82 




ENE 




Fine. 


31 


28 


8 





3» 


44 


30,06 


92 




ENE 




Fine. 


_ 


36 


2 





36 


48 


30,01 


74 




ENE 




Pine. 










, 


« 


^^^^ 


- 1 1 


■ 





t»S3 



m 




• 
•• 


ft 


r^ 


ov 


" 


00 


N 


i^ 


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1 


en 


m 


tn 


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1 


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n 


en 








vn 


8. 






OS 
OS 



us 


OS 










»H 


*m 


M 


N4 


M 


M 





to 


M 




N 


en 





8 


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i ■ 

1 


•148134 
nB3W 


• 


00 

00 


0. 

00 


00 




- *• 

00 




-vo " 


• NO : 

-• ^ 


>o- 




en 

00 


ts 

00 


OS 

NO 
00 


00 




mjfraif - 


? 


rv 


.2^ 


00 


tn 


-^ 


M 


n8 


N 


en 


00 


<fs 








1««37 





/t>* 


SO' 


>o . 


vo 


>o 


yj 


NO 


NO 


NO 


K 


r^ 




1 

1 




•IHSwh 


if 


rv 


!^ 


vo 


^ 


N 


00 


^ 


en 


^ 


u^ 


^ 


us 






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CN 


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OS 






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NO 








00 
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00 


en 





jt 

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u^ 
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• 


nesyj 


a 


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On 


OS 


OS 


0. 


o\ 


OS 





OS 


OS 


OS 


OS 







• 




»4 


N 


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N 


M. 


M 


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^ 


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1 




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M 

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2 

ft 


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• 
• 


& 


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N 

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5 


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OS 
N 






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en 






en 

6 


OS 
0" 


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1 

1 

1 




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0. 


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Thermomete 
within. 


ue3|^ 





^ 


mm 


♦0 

% 

v2 








tn 
SO 

OV 


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us 




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v% 

1 


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Mr 



vn 


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n 


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tTk 


vo 


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NO 


^^ 


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rs. 


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vo 


us 








1^ 


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if 




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1% 


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■ft 


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tout. 


UMW 


Q 


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^ 


vg 





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10 


v> 


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1 


00 


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00 


M3 


N 


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00 


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1' 


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M 


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tn 


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^ 


«^ 


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tn 


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6 


W^ 


»^, 


VO 


r>. 


tv 


00 


K 


00 


00 


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v\ 






i 
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1 




Six'i Therm, 
without* 


•148134 

UB3W 


t 





ov 

00 


«n 




NO 
0; 




00 

NO 


H 

^ 


'ts. 
NO 


m 

en 


Ov 
us 


en 


00 

UN 




•148134 
1M37 




1% 


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00 


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ts. 


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9 


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ob 
en 


St 


2* 

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;f 


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n 


M 


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t^ 





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1 


1t31c'3JO 


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t^ 


rs* 


0» 


00 


00 


00 


3 


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1 






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1. 


c 

9 


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1 

J. 


1 

J. 


j_ 


1 
^ 


5 

£ 


1 





C 27 3 



Variation of the Magnetic Needle , 

1804. 

March - - - 24^ n'.g 

June - - - - 24^ 8'.4 

July - - - 24*. 10'. 8 

September « - - 24'. 11 '.3 

December * - 34^ll^4 



X 



■^f- • 



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