DR. DALTON ON THE CONSTITUTION OF THE ATMOSPHERE. 
355 
namely, multiply the three leading decimals in the specific gravity of the liquid by 13, 
and the product will give the aggregate weight in grains of sulphur and lime in 1000 
water grain measures of the liquid ; of this aggregate -j^-th will be sulphur, and T 4 3 th 
lime. 
With regard to the residue after boiling and its analysis, it is obvious the residue 
must consist chiefly of sulphur and lime, which for want of due continuance of the 
ebullition have escaped combination ; and there may be some impurities in the 
sulphur, or the hydrate of lime may not be free from carbonate, &c. ; but when the 
residue is comparatively small no material disturbance of proportions in the qnadri- 
sulphuret can take place. If the residue be chiefly sulphur, its quantity may be ap- 
proximated by ignition ; but if lime is in excess, it may be estimated by the quantity 
of muriatic acid required to saturate it. 
The following Table exhibits a selection of the principal varieties in the proportions 
of ingredients and products obtained so as to illustrate the foregoing statements. 
Table of Proportions in Quadrisulphuret of Lime. 
Quantities of hydrate of lime and 
sulphur mixed. 
Proportions 
of lime and 
sulphur. 
Quantity of liquor obtained in water grain measures, 
and quantities of lime and sulphur in it. 
Measures 
of oxygen 
required to 
saturate 
100 liquid. 
Quantity of residue when dried. 
1 
Hydrate. Sulphur. 
120 = 90 lime + 210 
Lime. 
4 : 
Sulph. 
3100 of 1 '056 containing 70 lime + 156 sulph. 
900 
56 = 16 lime + 40 sulph. 
2 
50 = 2,11 lime + 50* * * § 
4 : 
2200 of 1-0240 containing 21 lime + 47 sulph. 
400 
20 = 12 lime + 4 sulph. + loss. 
3 
150 = 112f lime + 200 
4 : 
7 + 
1450 of 1-146 containing 85 lime + 190 sulph. 
2350 
f20 = 7 lime + 13 sulph. 
4 
96 = 72 lime + 168 sulph. f 
4 : 
H 
2800 of 1-056 containing 63 lime + 141 sulph. 
900 § 
34 = 9 lime + 25 sulph. 
5 
35 = 26 lime + 140 sulph. 
4 : 
21-6 
1600 of 1-037 containing 23-7 lime + 53 - 3 sulph. 
600 § 
83 all sulph. 
On the Quantity of Oxygen in the Atmosphere. 
Since the commencement of the present century it has been ascertained beyond 
dispute that the chief constituents of the atmosphere, oxygen gas and azotic gas, are 
in the same proportion in all countries and at all times, except when influenced by 
local circumstances ; namely, 21 per cent, of volume of oxygen, and 79 per cent, of 
azote, neglecting fractions : other elements are found in the atmosphere, but they 
are comparatively insignificant in quantity, namely aqueous vapour, carbonic acid, 
&c. The experiments have generally been made on air collected at the surface of 
the earth ; and it may be remembered that I have endeavoured to prove in various 
essays that the diffusion of gases one amongst another as well as in vacuo, is owing 
to the repulsive powers peculiar to the particles of each particular gas, otherwise we 
* Boiled in a flask loosely corked. 
t Lost some of the ingredients by boiling over ; hence a deficiency. 
1 Boiled in a flask with great care. 
§ The oxygen was determined by especial care in these two cases. 
MDCCCXXXVII. 3 A 
