PHYSICAL AND CHEMICAL AGENTS UPON BLOOD. 
697 
Two ounces of well defibrinated sheep’s blood, after being arterialized by constant agi- 
tation with renewed portions of air during twenty minutes, were put into a receiver with 
100 per cent, of atmospheric air and kept during twenty-four hours in a room the tem- 
perature of which varied from 6° to 12° C. Result : — 
No. 21. — In 100 parts of air. 
Oxygen . . . 
Carbonic acid . 
Nitrogen . . 
^.QgjTotal oxygen 15*81 
84*19 
A similar portion of the same blood as the preceding, after being exposed to the air in 
an open glass vessel during sixty hours, was treated in an exactly similar manner, and then 
placed in a receiver with 100 per cent, of air. The temperature of the room during the 
time of the experiment varied, as before, from 6° to 12° C. The blood after the sixty 
hours’ exposure had become of a dark venous hue, but it still arterialized readily on being 
agitated with fresh portions of air. It smelt slightly, as if putrefaction had begun. 
Under the microscope the red blood-corpuscles were perfectly distinct. Result : — 
No. 22.- 
Oxygen . . . 
Carbonic acid . 
Nitrogen . 
-In 100 parts of air. 
2*88 
3-69J 
93*43 
Total oxygen 6*57 
This blood, which was of a bright arterial hue when put into the receiver with the 
air, at the end of the twenty-four hours had again resumed the venous colour. On 
shaking the vessel the blood looked as if it were decomposed. It remained of a dark 
purple colour on the sides of the glass, although the blood was at this time eighty-four 
hours old. On removing it from the receiver, and shaking it with renewed portions of 
atmospheric air, it again assumed the arterial tint. After the sheep’s blood was 136 hours 
old it was of a dark purple colour, and when a thin layer was spread over a white plate 
it looked quite granular. When examined with the microscope, the blood-corpuscles 
were still found perfectly distinct in their outline, and on being measured they averaged 
4 ijo millim. (j oT o 6 o inch) in diameter. The blood arterialized readily on being shaken 
with fresh air. 
A third portion of this blood was taken and subjected in every respect to precisely the 
same treatment as in the two preceding cases. Result : — 
No. 23. — In 100 parts of air. 
Oxygen. . . . 1*01' 
Carbonic acid . . 4*31, 
Nitroeen . . . 94*68 
Total 
0X Ji 
5*32 
A fourth portion from the same blood, after it was 184 hours old, still became of an 
5d2 
