322 Relation between the Specific Gravities of [Nov, 
Oxygen a-iiejeid sate Liss ost pig dal. Ayers 
be he 
Azotebuuat.aw. seh ween Skee a, ie 
Hence, then, it must be considered in the light of a pure che- 
mical compound; and indeed nothing but this supposition will 
account for its aniformity all over the world, as demonstrated by 
numerous experiments. From these data the specific gravities of 
oxygen and azote (atmospheric air being 1°000) will be found to be,* 
QR TRIED a poste Fine wr vip jovsins al c's wiode nyse 0) LLL 
A ZOEE., (Bde fea ah ah aceite Oe 6 Bimal vege are 
2. Hydrogen.—The specific gravity of hydrogen, on account of 
its great levity, and the obstinacy with which it retains water, has 
always been considered as the most difficult to take of any other 
gas. These obstacles made me (to speak in the first person) despair 
of arriving at a more just conclusion than had been before obtained 
by the usual process of: weighing ; and it occurred to me that its 
specific gravity might be much more accurately obtained by calcu- 
lation from the specific gravity of a denser compound into which it 
entered ina known proportion. Ammoniacal gas appeared to be the 
best suited to my purpose, as its specific gravity had been taken 
with great care by Sir H. Davy, and the chance of error had been 
much diminished from the slight difference between its sp. gr. and 
that of steam. Moreover, Biot and Arrago had obtained almost 
precisely the same result as Sir H. Davy. Thesp. gr. of ammonia, 
according to Sir H. Davy, is *590164, atmospheric air being 1°000, 
We shall consider it as *5902; and this we are authorized in doing, 
as Biot and Arrago state it somewhat higher than Sir H. Davy. 
Now ammonia consists of three volumes of hydrogen and one volume 
of azote condensed into two volumes. Hence the sp. gr. of hydrogen 
will be found to be -0694,+ atmospheric air being 1°0000, It will 
be also observed that the sp. gr. of oxygen as obtained above is just 
16 times that of hydrogen as now ascertained, and the sp. gr. of 
azote just 14 times. f 
3. Chlorine.—The specific gravity of muriatic acid, aecording 
to Sir H. Davy’s experiments, which coincide exactly with those of 
* Let x =sp.egr. of oxygen, 22°22 =a 
y = sp. gr. of azote. Vil =b 
4 
Then roi tahda =], 
0 
Andx:4y:a:b 
4 
Hence 5 — 4y = ae - 
And y= oe = 9722, Anda=5—4y=1:111i1 
ith Aa+4b a? # r 
+ Let x = sp. gr, of hydrogen, 
. “O796 
Then <a = "DOU, 
“1804 — +9722 
pens O18) A bkod, 
$ M1111] + -0694 = 16. And +9722 + -0694 =.14, 
Hence x = 
