PROFESSOR GRAHAM ON THE MOTION OF GASES. 
599 
Capillary B shortened . — The tube was preserved in its last position, but its length 
reduced to 1 4*5 inches. It now allowed 1 cubic inch of air to pass into a vacuum 
in 6*4 seconds ; or twice as rapidly as when entire. 
Table XIII. — Transpiration by Capillary B (14^ inches long) into a one-pint jar. 
Baroin. 30T2. 
Gauge barometer 
Air. 
Oxygen. 
Nitrogen. 
Carburetted hydrogen. 
Hydrogen. 
Carbonic acid. 
in inches. 
x * 
II. 
III. 
II. 
III. 
i. 
II. 
i. 
11. 
III. 
i. 
II. 
in. 
I. 
II. 
62° F. 
62° F. 
62° F. 
63° F. 
63° F. 
62° F. 
61° F. 
62° F. 
62° F. 
62° F. 
62° F. 
62° F. 
62° F. 
28 
0" 
0" 
0" 
0" 
0" 
0" 
0" 
0" 
0" 
0" 
0" 
O" 
0" 
0" 
0" 
0" 
20 
75 
/o 
75-5 
82-5 
83-5 
82 
72 
72 
48 
48 
48 
34-5 
34 
34 
69 
69 
12 
89o 
89-5 
89-5 
995 
99-5 
100 
8 7 5 
88 
57 
57 
57 
41 5 
41-5 
41-5 
81 
80-5 
4 
158 
157 
157-5 
175 
175-5 
174-5 
152-5 
152-5 
98 
98 
98 
75 
75 
75 
137-5 
136-5 
2 
91-5 
91 
92 
102 
103 
1025 
91 
89-5 
56 
56 
555 
45-5 
45-5 
45 
77 
775 
From 28 to 12 in. 
164-5 
164-5 
164-5 
182 
183 
182 
159-5 
160 
105 
105 
105 
76 
75-5 
75-5 
150 
149-5 
From 28 to 2 in. 
414 
412-5 
414-5 
459 
461-5 
459 
403 
402 
259 
259 
258-5 
196-5 
196 
195-5 
364 
363-5 
Mean Results. 
Gauge barometer. 
Air. 
Nitrogen. 
Carburetted 
hydrogen. 
Hydrogen. 
Carbonic acid. 
From 28 to 12 inches 
From 12 to 4 inches ■ 
From 4 to 2 inches < 
f Time in seconds 
Time of oxygen = 1 . . . 
f Time in seconds 
Time of oxygen=l... 
Time in seconds 
Time of oxygen = l... 
164-5 
0-9023 
157-5 
0-9000 
91*5 
0-8926 
159-75 
0-8763 
152-5 
0-8714 
90-25 
0-8804 
105 
0-5728 
98 
0-5600 
55-83 
0-5447 
75-66 
0 4150 
75 
0-4285 
45-33 
0-4325 
149*7 
0-8211 
137 
0-7828 
77*25 
0-7546 
From 28 to 2 inches < 
Time in seconds 
Time of oxygen = 1 ... 
413-7 
0-8999 
402-5 
0-8755 
258-83 
0-5632 
196 
0-4263 
363-75 
0-7912 
The times are now too short for accurate numerical determinations, but it is ob- 
vious that while the relative times of air and nitrogen are little changed, particularly 
from 28 to 4 inches, the times of hydrogen and carbonic acid are sensibly affected by 
effusion, and most so in the upper part of the scale ; the coefficient of hydrogen fall- 
ing to 0-4150, while that of carbonic acid rises to 0-8211. From 4 to 2 inches, the 
rates are 0*4325 and 0*7546 ; numbers which still diverge a little from the empirical 
coefficients, but both in the direction of the effusion influence. 
Reduced to 7 inches in length and now allowing 1 cubic inch of air to pass into a 
vacuum in 3*4 seconds, this capillary was found to be still less adapted for transpira- 
tion. In a series of observations, which are not of sufficient importance to be par- 
ticularly detailed, the coefficients of the gases in the range from 28 to 12 inches, 
were, — air 0*9194, nitrogen 0*8983, carburetted hydrogen 0*6029, carbonic acid 0*9028, 
and hydrogen 0*3930 : numbers which demonstrate an increasing interference of 
effusion. In the range from 12 to 4 inches, the coefficients were, — air 0*9114, nitrogen 
0*8851, carburetted hydrogen 0*5764, carbonic acid 0*8303, hydrogen 0*4180. 
Of this last portion of capillary B, 5*5 inches were found to contain 2*78 grains of 
mercury; which gives the tube a mean diameter of 0*0137, or y^rd of an inch. 
Capillary C. — This was a tube of exceedingly fine bore; 8*3 inches of the tube 
