412 



BLOOD. 



From these experiments it follows that of all 

 animals birds are those whose blood is richest 

 in globules and in fibrine, as they are those 

 also whose temperature is highest and whose 

 respiration is most active. The blood of the 

 mammalia contains rather less, and there is a 

 difference to be noted in this respect between 

 the carnivorous or omnivorous tribes, and the 

 herbivorous, the proportion of solid particles 

 being larger in the two former than it is in the 

 latter. We see, indeed, that in man, the dog, and 

 the cat, they enter in the proportion of twelve 

 or thirteen per 1000, whilst in the horse, sheep, 

 calf, and rabbit, they form no more than from the 

 seventh to the ninth per 1000 of the general 

 weight of the blood. But the number of species 

 hitherto examined is not so considerable as to 

 enable us to say that the circumstance, now 

 announced, is to be regarded in the light of a 

 physiological law. Among the cold-blooded 

 vertebrate animals the blood becomes much 

 poorer in solid particles ; the tortoise, indeed, 

 seems, from the results in the table, to form 

 an exception to this fact, but the circumstances 

 under which the estimates were made in regard 

 to it, and which it would be too long to enter 

 upon here, explain the anomaly.* 



The proportion of serum and of solid parti- 

 cles also presents considerable varieties in the 

 blood of different individuals of the same 

 species. From the investigations of M. Lecanu 

 we observe that the proportion of water in the 

 human blood varies from 853 to 778 in 1000, 

 and that of the solid particles from 148 to 68. 



The differences of sex have also a certain 



* Ann. dc Chimic, t. xxiii. 



influence on the composition of the blood : M. 

 Lecanu found in regard to 



The blood of man (in 1000 parts.) 



Solid particles. Water. 



Maximum ... 148 805 



Minimum ... 115 778 



132 791 



The quantity of albumen did not appear to 

 differ in the blood of the two sexes. 



The richness of the blood also varies ac- 

 cording to the temperament of individuals, 

 as may be seen by the following table. 



Men. 



Women. 



