358 
PROFESSOR GRAHAM ON THE MOTION OF GASES. 
of hydrogen 534 and 534 seconds ; thermometer 58°‘5, barometer 30'068. These 
observations give the transpiration time 0’7275 for carbonic acid and 0*4355 for 
hydrogen. 
(3.) The times of air being 1109 and 1109 seconds, the times of carbonic oxide 
were 1070 and 1070 seconds ; thermometer 67°*5, barometer 29*808. 
Transpiration time of carbonic oxide 0*8683 
(4.) The times of air being 1098 and 1099 seconds, the times of nitrogen were 
1064 and 1062 seconds ; thermometer 64° to 65°, barometer 29*904. 
Transpiration time of nitrogen 0*8708 
(5.) The times of air being 1084 and 1084 seconds, the times of hydrogen were 
529 and 529 seconds ; thermometer 69°, barometer 30*242 inches. 
Transpiration time of hydrogen 0*4392 
In the present experiments with hydrogen, the precautions formerly referred to for 
excluding as much as possible the access of a sensible trace of air from the water of the 
pneumatic trough were put in practice. The times obtained for this and all the other 
gases, with the present capillary, will be observed to be in the highest degree normal. 
(6.) The times of air being 1095 and 1096 seconds, those of olefiant gas were 641, 
641 and 641 seconds; thermometer 69°, barometer 30*102. 
Transpiration time of olefiant gas 0*5265 
The time formerly obtained for the same gas by the capillary H of small resistance 
was 0*5186. This new capillary M was afterwards very fully employed in determining 
the times of various other gases and vapours, and in examining the influence of 
pressure and temperature. It is therefore desirable to have the preceding results 
which this capillary gives with the more familiar gases. 
(7.) The times of air being 1120 and 1120 seconds, those of protocarburetted hy- 
drogen (the gas of the acetates) were 684, 686 and 685 seconds ; thermometer 61°*5, 
barometer 29*844. 
Transpiration time of protocarburetted hydrogen . . . 0*5504 
The time 0*5515 was formerly obtained for this gas by capillary E, which was a 
long tube of small resistance, very like capillary IT. 
(8.) The times of air being 1110 and 1111 seconds, those of binoxide of nitrogen 
(NO 2 ) were I070, 1070 and IO7O seconds; thermometer 60°*5, barometer 29*948 to 
29*782 inches. 
Transpiration time of binoxide of nitrogen 0*8672 
This result is in accordance with the conclusion drawn from my former experi- 
ments upon the same gas, made with capillary E, namely, that the time of nitric 
oxide gas coincides with that of nitrogen and carbonic oxide. 
(9.) Observations were made with the same capillary M a little reduced in length, 
namely, to 50*5 inches, and with a smaller aspirator-jar ; the range observed of the 
attached barometer being still from 28*5 to 23*5 inches. 
It now gave for the transpiration time of air 0*8984. 
