124 FOURTH REPORT — 1834. 



blood; Scudamore half a cubic inch from six ounces; Sir Humphry 

 Davy rather more than one cubic inch from twelve cubic inches 

 of blood. Dr. Clanny finds that the gas developed is principally 

 nitrogen. Dr. J. Davy asserts, from his experiments, that in no 

 case is carbonic acid ever developed from fresh-drawn blood ; 

 that, on the contrary, it absorbs one fourth of its bulli of carbo- 

 nic acid, which becomes combined. Miiller has repeated the 

 analysis, both with fresh sheep's blood and with that of man. 

 Even under a heat which amounted to 200° F., one pound of the 

 former gave oif only 1*8 cubic inch of gas : of this quantity 

 not one fifth cubic inch was absorbed by lime water ; and this 

 small quantity of carbonic acid he attributes to the action of the 

 air contained in the tube of his apparatus upon the blood. He 

 repeated the experiment in such a way as to exclude the air, and 

 obtained no trace of carbonic acid, nor any, except the merest 

 bubble, of any other gas. He further found, that blood artifi- 

 cially impregnated with carbonic acid did not yield it again un- 

 der the air-pvmip*, and thus has confirmed the same observation 

 of Dr. J. Davy. Mitscherlich, Gmelin, and Tiedemann have lately 

 performed another experiment with the same result. They in- 

 troduced small metallic tubes, provided with stop-cocks, into the 

 artery and vein of a Dog. After all air was evacuated from the 

 tubes, by allowing the blood to flow, they were brought under 

 glass cylinders inverted over mercury. The cylinders, half filled 

 with blood, were placed under the air-pump. On exhausting, 

 bubbles arose, so that the quicksilver, which had stood half an 

 inch above that in the cup, sunk about an inch. But when 

 the air was gradually readmitted to the bell of the pump, they 

 disappeared ; showing that they did not consist of gas, but of 

 watery vapour which had filled a vacuum. Both kinds of blood 

 comported themselves similarly. The authors found that the 

 blood contains carb. acid combined ; for blood mixed with vine- 

 gar gave bubbles under the air-pump, which, when venous blood 

 was emploj^ed, did not entirely disappear on readmission of the 

 air : hence the alkaline nature of the blood depends not upon 

 caustic alkalies, but upon their carbonates t> 



The proportion of solid to fluid matter in the blood has been 

 determined by Prevost and Dumas, in agreatnumber of animals. 

 They find that in Man the solid are to the fluid : : 1 : 9. 



In carnivorous animals there are more cruor and fibrin together 

 than in graminivorous : in young animals less than in old of the 

 same species :}:. 



* Miiller, Phys'wlogie, i. 313. 



t Archiv.fur Anat. utid Phys., Miiller, 1834, 103. J J.Davy. 



