100 
NATURE 
vJ 
[| Mov. 30, 1882 
the auroral display, the extremely singular phenomenon which 
has been described by several of your correspondents. It 
looked exactly like a white cloud, about 20° long and 2° wide, 
tapered somewhat from the middle to each end ; but it was more 
luminous thana cloud could well have been at that time. When 
first seen, its nearest end may have been 30° east of the moon. 
Its length was nearly parallel to the horizon, and continued so till 
lost sight of about as much to the west of the moon; and its 
passage over an area of some 80° occupied probably less than a 
minute. It passed very near to the moon, but I cannot say 
whether over it or not. CHARLEs J. TAYLOR 
Toppesfield Rectory, Halstead, Essex, Nov, 25 
FOLLOWING up my last week’s letter concerning the electric 
meteoroid, if one may so term it, of the 17th inst., I have sifted 
all the testimony within my knowledge, assigning a numerical 
weight to each report from internal evidence of its probable 
value, and correcting for latitude where the altitude of the moon 
was made the standard of comparison. With dataso precarious, 
and triangles so ill-conditioned, the results can of course only be 
regarded as a very rough approximation to the truth ; for what 
they are worth, however, they are as follows :—1. That the 
course of the meteoroid was about S. 70° W. Probably it was 
71° 45’, the complement of the magnetic declination. 2. That 
there was a proper motion of a little more than a mile a minute. 
3. That the path was vertically over a line upon the earth’s sur- 
face, whose least distance from Greenwich was 72 miles. 4. 
That the actual elevation was 44 miles. On this reckoning the 
body would seem to have crossed in the zenith in North Bel- 
gium, the Boulogne district, Cherbourg, and the north coasts of 
Brittany. STEPHEN H. SAxBy 
East Clevedon Vicarage, Somerset, November 28 
My observation at Ramsbury, near Hungerford, was to the 
effect that while watching the northern aurora, my attention was 
called, at ten minutes past six, to this monster meteor, then 
slowly approaching in a direct line to the moon, which was 
shining most brilliantiy. It seemed to pass exactly over the 
disc, and reappeared on the side, much reduced in size, as if 
going away from us; and at a distance of about 6° from the 
moon, scarcely seemed to measure more than 5° in length, it 
being then about 6h. 8m., which corresponds with the position 
over Sidmouth at that time. It was very definite In form, like 
a torpedo. I estimated its length at 15°, and 3° in breadth. I 
hope to have a hand-made photograph of its appearance ready 
for publication, by the Autotype Company, in a few days, and 
on the same sheet is a hand-delineation of the great comet to the 
same scale. ALFRED BATSON 
The Rookery, Ramsbury 
Lavoisier, Priestley, and the Discovery of Oxygen 
In the‘last number of this journal my friend Mr. Tomlinson 
has criticised my observations on the respective claims of 
Lavoisier and Priestley to the discovery of oxygen. Without 
examining, or attempting to refute one of my arguments, and 
without the citation of any warrant, or authority, he has stated 
his opinions with an asseveration worthy of a 15th century 
Professor of Dogmatic Theology, His letter consists of five 
general statements, and zie dogmatic assertions. I have 
endeavoured to show that of the former, ‘wo are self-evident 
truths, or at least universally-admitted conclusions, while the 
remaining ¢hree are misstatements; and that of the latter five 
are completely erroneous,’ while ¢ivee are open to question, and 
onz is correct. 
1. The universally admitted conclusions are:—(a) that 
“*chemistry has no nationality,” and that ‘‘discoverers are 
mutually dependent.” Nothing that I have said can possibly 
be construed into the expression of a shadow of doubt con- 
cerning the truth of either of these statements. 
2. The three misstatements are that (a2) I have “thought it 
necessary to revive the old oxygen quarrel,” (¢) that I have 
‘*taken an unpatriotic part against Priestley,” and (c) *‘ endorsed 
the complacent statement of Wurtz, that chemistry is a French 
science founded by Lavoisier.” If it be reviving a quarrel and 
acting an unpatriotic part against a man, to show that by the 
light of evidence hitherto overlooked one of the greatest scien- 
tific men of the last century has been unfairly accused of dis- 
honesty, I am quite willing to be considered unpatriotic and a 
quarrel-monger. As to endorsing the statement of M. Wurtz, 
all I say is that he did not say it ‘‘ without reason.” Many 
people regard the assertion as quite unreasonable. I confess I 
co not, but at the same time I do not mean to say that I fully 
accept it. 
[As to my ‘‘forgetting, perhaps, that the title ‘La Chimie 
Francaise’ was invented by Fourcroy, and objected to by 
Lavoisier,” I may say that I do not see that this bears the least 
upon the question. Lavoisier’s own words are ‘‘Cette théorie 
n’est done pas, comme je l’entends dire la theorie des chimistes 
francais, elle est Ja mienne, et c’est une propriété que je réclame 
aupres de mes contemporains et de la postérité.” (uvres de 
Lavoisier, tome 2, 1862, p. 104.) Dr. Thomas Thomson 
(Aist. of Chem. p. 101, vol. ii.) says, ‘‘ Lavoisier’s objection, 
then, to the phrase Za Chimie Francaise, is not without reason, 
the term Lavoisterian Chemistry should undoubtedly be substi- 
tuted for it.” But this does not affect the question whether or 
no chemistry is a French science as M. Wurtz puts it, for surely 
Lavoisier was a, Frenchman of the French. I say nothing, 
however, as to the justification of the remark that chemistry zs 
a French science.] 
3. ‘‘ That the compound is always equal to the sum of its 
elements was known long before Lavoisier” remarks Mr. Tom- 
linson, I have nowhere asserted that it was not, but the state- 
ment is new to me, and I should like to have references. 
4... . ‘So early as 1630 Rey gave the true explanation of 
the increase of the weight of metals by calcination.” Any one 
who will take the trouble to read through Rey’s essay “‘ sur da 
recherche dela cause pour laquelle Vestain et le plomb augmentent 
de poids quand on les calcine,” cannot fail to observe how very 
vague his ideas on the subject were. He indeed attributed the 
increase of weight to thickened air (7azr espessi), but the fol- 
lowing, as I have elsewhere stated, seems to have been his mode 
of reasoning :—Air possesses weight ; it may be produced by 
heating water, which during distillation separates into a heavier 
and a lighter part ; hence as air approximates to a liquid nature, 
it may be supposed to be separated into a heavier and a lighter 
part by the action of heat ; now the heavier part (the ‘‘ dregs ”) 
of air is more nearly allied to a liquid than air, for it has as- 
sumed a ‘‘ viscid grossness,” and this part attaches itself to calces 
during the process of calcination, and causes such of them as 
possess much ash to be heavier than before calcination. If we 
calcine a vegetable or animal substance there is no gain of 
weight, because the assimilated thickened air weighs less than 
the volatile matter expelled by heat; but in the case of a metal 
the assimilated air weighs more than the volatile matter expelled, 
hence there is a gain of weight. Thus he imagined that all 
calces, from a vegetable ash to a metallic calx, attract this thick- 
ened air. It can scarcely be said that a man with these ex- 
tremely crude notions ‘‘ gave the true explanation of the increase 
of weight of metals by calcination.” 
5 and 6. ‘‘ Lavoisier’s note of 1772 was, as he admitted, 
based upon Priestley’s earlier experiments, begun in 1744.” I 
can nowhere find in Layoisier’s writings any admission of the 
kind alluded to. (Will Mr. Tomlinson give references ?). On 
the other hand, I do finda note by Lavoisier at the end of Chap. 
VI. De la calcination des metaux, published in the Opuscules 
Physiqgues et Chimigques (1774), (Geuvres, Vol. I., p. 621), in 
which he says, ‘‘ Je n’avais point connaissance des experiences 
de M. Priestley, lorsque je me suis occupé de celles rapportées 
dans ce chapitre. Ila observé, comme moi et avant moi, .. . 
&c., &c.’’ This would seem to sufficiently disprove the former 
statement. 
Mr. Tomlinson speaks of Priestley’s ‘‘ earlier experiments 
begun in 1744.” Now Priestley was born in 1733, and although 
no doubt a clever fellow he certainly did not begin to experi- 
ment at e/even years of age! His first paper on gases was pub- 
lished thirty-nine years later, viz. in 1772. 
7. That ‘*the acceptance of Lavoisier’s doctrine was mainly 
due to the capital discovery of the composition of water by 
Cavendish in 1784,” I utterly deny ; and if desirable will shou 
cause why. Nevertheless, as it has been so asserted, we may, 
for the present at least, regard it as an open question, 
8. Mr. Tomlinson calls Black, Priestley, and Cavendish, ‘‘the 
founders of pneumatic chemistry.”’ Surely John Mayor and Stephen 
Hales have a better right to the title. 
g. ‘‘ Priestley discovered oxygen in 1774.” This, no doubt, is 
true in a sense because everybody says so. If it means that he 
got a gas from red oxide of mercury it is true. But let us not for- 
get :—(a) that he discovered it by a random experiment, ‘‘ by 
