ITS QUANTITY IN THE BODY. 269 



in such a relation to the blood that the state of the latter is almost 

 immediately reflected in them (as indeed we see from the different 

 composition of the separate portions of the blood in one and the 

 same venesection, see p. 262), if the blood did not continually 

 give off water to the kidneys and other excretory organs, and 

 lastly, if the vessels were mere waterproof canals, without openings 

 for the escape of the water, and for the importation of solid parts. 



The discrepancies in the views of different physiologists 

 in reference to the quantity of blood contained in the body of 

 an adult man, are sufficiently obvious, when we remember that 

 Blumenbach estimated it at 4 or 5 kilogrammes [from 8*5 to 11 

 pounds], and Reil at fully 20 kilogrammes [or 44 pounds]. In 

 the present day the blood is generally estimated at 10 kilogrammes 

 [or 22 pounds], which is equal to about the 8th part of the weight 

 of the whole body. If I may advance the opinion at which I have 

 arrived from experiments prosecuted on the bodies of two executed 

 criminals, I should estimate the blood in the body of a young man 

 as somewhat below the above quantity, namely, at from about 8 

 to 8'5 kilogrammes [or from 17'5 to nearly 19 pounds]. 



My friend, Ed. Weber, determined, with my co-operation, the 

 weights of two criminals both before and after their decapitation. 

 The quantity of the blood which escaped from the body, was 

 determined in the following mariner : water was injected into the 

 vessels of the trunk and head, until the fluid escaping from the 

 veins had only a pale red or yellow colour ; the quantity of the 

 blood remaining in the body was then calculated, by instituting a 

 comparison between the solid residue of this pale red aqueous fluid, 

 and that of the blood which first escaped. By way of illustration, 

 I subjoin the results yielded by one of the experiments : the living 

 body of one of the criminals weighed 60140 grammes, and the 

 same body after decapitation 54600 grammes; consequently, 5540 

 grammes of blood had escaped. 28'560 grammes of this blood 

 yielded 5*36 grammes of solid residue ; 60'5 grammes of sangui- 

 neous water collected after the injection, contained 3'724 grammes 

 of solid substances. 6050 grammes of the sanguineous water that 

 returned from the veins were collected, and these contained 37*24 

 grammes of solid residue, which corresponds to 1980 grammes of 

 blood ; consequently, the body contained 7520 grammes of blood 

 (5540 escaping in the act of decapitation, and 1980 remaining in 

 the body) ; hence, the weight of the whole of the blood was to that 

 of the body nearly in the ratio of 1 : 8. The other experiment 

 yielded a precisely similar result. 



