366 
PROFESSOR GRAHAM ON THE MOTION OF GASES. 
accidental, but the circumstances that 14, which expresses the density and time of 
nitrogen, is double the time of hydrogen 7? and that 22 expresses the density of car- 
bonic acid, to which carburetted hydrogen presents a certain chemical analogy in 
composition, appear to afford some physical basis for it. 
The time of protocarburetted hydrogen may also be stated to be one-fourth more 
than 0’44, the usually observed time of hydrogen itself. 
2. Olejiant Gas. 
The circumstance that olefiant gas has the same theoretical density as nitrogen and 
carbonic oxide, and yet differs greatly from these gases in transpirability, gives a 
peculiar interest to the transpiration time of that gas. The olefiant gas used was 
always prepared in the following manner : — Fifty-four volumes (water ounce mea- 
sures) of oil of vitriol were mixed with twenty- eight volumes of water and cooled, 
which gave an acid of specific gravity T600. To this twenty-four volumes of alcohol, 
generally of specific gravity 0*84, were added, and the mixture allowed to stand over 
night. The gas was evolved by a heat of about 320° Fahr., and transmitted, for the 
purpose of purifying it through five wash-bottles, the first containing potash, the 
second water, the third oil of vitriol, the fourth potash, and the fifth oil of vitriol. 
The process yielded a good deal of ether, with a large product of gas. 
My old experiments, with capillary H of great length but small resistance, gave 
0'5186 as the transpiration time of this gas. I subsequently obtained the number 
0’5241 with capillary K of 8‘75 inches in length, and also of small resistance. With 
capillary M of 52’5 inches in length, and of considerable resistance, I also obtained 
the number 0‘5265 ; the gas in all these cases passing into the nearly vacqous jar 
under the pressure of the atmosphere. But the most complete series of experiments 
was made upon this gas in a compressed state, in the globular digester of 72 cubic 
inches in capacity, the gas escaping into air. The capillary M was employed of 50*5 
inches in length. 
Table XI. — Transpiration of Olefiant Gas and Air (into air). 
Height of gauge barometer 
above 1 atmosphere. 
Air. 
Olefiant gas. 
Experiment I. 
Experiment 11. 
Experiment I. 
Experiment II. 
inches. 
// 
// 
20 
0 
0 
0 
0 
15 
198 
196 
116 
116 
10 
285 
285 
165 
165 
8 
l6l 
l6l 
93 
93 
6 
213 
213 
120 
121 
4 
307 
307 
174 
174 
2 
530 
530 
301 
301 
1 
529 
530 
299 
300 
The fall from 20 to 10 inches requires 482 seconds in air and 281 in olefiant gas, 
