692 
PROFESSOR HARLEY ON THE INFLUENCE OF 
had an equal amount of powdered glass mixed with it. Both receivers were put aside 
in a place where the temperature never exceeded 7° C. At the end of five days, during 
which period they were repeatedly shaken, the air was analyzed for carbonic* acid. 
No. 5. — In 100 parts of air. 
Carbonic acid from blood, plus quicksilver . . I - 72 
„ „ „ „ „ glass . . . T30 
As it appeared from this and the foregoing that the action of the mercury was some- 
thing more than merely mechanical, in order to ascertain the influence of motion alone, 
two equal portions of the same fresh venous blood from an ox were placed in receivers 
with similar proportions of atmospheric air (1 vol. of blood to 3 vols. air) and kept at a 
temperature of 30° C. during six hours. In each receiver was placed a small quantity of 
powdered glass, in order the more effectually, when the receivers were shaken, to mix the 
blood. The first receiver was shaken only three minutes at a time, the second five. In 
all other respects they were treated exactly alike*. 
Air after being enclosed during six hours at a temperature of 30° with venous blood 
shaken with glass, three minutes at a time. Result : — 
No. 6. — In 100 parts of air. 
Oxygen . . . 
Carbonic acid . 
Nitrogen . . 
J^j-Total oxygen 18-20 
81-80 
Same blood as the preceding, under precisely the same circumstances, but shaken 
during five minutes at a time. Result : — 
No. 7. — In 100 parts of air. 
Oxygen .... 
Carbonic acid . . 
Nitrogen . . . 
It thus appears that the mere effect 
gases interchanged. 
1 4.40} 
4-44) Total ox ^ en 18 ' 93 
81-07 
of motion has an influence on the amount of 
(c) Influence of Time on the interchange of gases between the blood and air. 
It was found from a series of experiments (as might have been expected from our 
knowledge of the respiratory process) that the longer air is retained in contact with 
blood, the greater is the change worked in its chemical composition. Thus it was found 
* It may be bere mentioned that during tbe course of these experiments it was found necessary, in order to 
arrive at anything like correct results, not only to use (in the comparative experiments) the blood of the same 
species of animal, but of the same bleeding ; as for some cause or other, the state of the digestion or the health 
of the animal, different bleedings invariably gave slight differences in result. 
