CHEMICAL COMPOSITION. xxxvii 



the dried corpuscles too much, viz. to 129 parts per 1000 of blood. Le- 

 canu also gives it at from 120 to 130 : Becquerel and Rodier at from 131 

 to 152. Schmidt, from three modes of calculation, which it is needless here 

 to explain, arrived at the conclusion that the proportion of moist red cor- 

 puscles in 1000 parts of blood is from 480 to 520 ; but there are reasons 

 for regarding this as too high an estimate. He considers that in the moist 

 state they consist of 31 per cent, of solid matter and 69 per cent, of water : 

 on this understanding, of course, much of the water estimated by the loss in 

 drying blood must be assigned to the corpuscles.* 



Different observers agree that, as a general rule, the proportion of red particles is 

 greater in the blood of the male sex than in that of the female. Lecanu gives the 

 following mean result, derived from numerous analyses, exhibiting the proportion of 

 dry crassamentum and water in the blood of the two sexes. No deduction is made 

 for the fibrin ; but, considering its small relative quantity, any possible variation in 

 it cannot materially affect the general conclusion. 



Male. Female. 



Crassamentum, from . 115-8 to 148 . . 68'3 to 129'9 



Water . . . . 778 to 805 . . 790 to 853 



Becquerel and Rodier state the crassamentum in the female at from 113 to 137. 

 Lecanu found the following differences in the crassamentum according to 

 temperament : 



Male. Female. 



Sanguine temperament . . . 136'4 . . . 126-1 

 Lymphatic temperament . . 116'6 . . . 117'3 



As regards age, Denis found the proportion of crassamentum greatest between the 

 ages of 30 and 40. Sudden loss of blood rapidly diminishes it. In two women who 

 had suffered from uterine haemorrhage, the crassamentum amounted to only 70 parts 

 in 1000. The same effect may be observed to follow ordinary venesection. In a 

 person bled three times in one day, Lecanu found in the first drawn blood 139, and 

 in the last only 76 parts of crassamentum in the 1000. This effect may be produced 

 very suddenly after a bleeding. Prevost and Dumas bled a cat from the jugular 

 vein, and found 116 parts of crassamentum in 1000, but in blood drawn five minutes 

 afterwards, it Avas reduced to 93. The sudden loss of blood probably causes a rapid 

 absorption of serous and watery fluid into the vessels, and thus diminishes the relative 

 amount of the red particles. It is found that the blood of warm-blooded animals is 

 richer in crassamentum than that of the cold-blooded ; and, among the former, the 

 proportion is highest in the class of birds. 



Liquor Sanguinis. The fluid part of the blood, as already described, 

 separates spontaneously into fibrin and serum. The fibrin may be obtained 

 by stirring the blood as soon as possible after it is drawn, or by washing 

 the crassamentum with water, to free it from cruor. Procured in either 

 of these ways, the fibrin contains pale corpuscles and a small portion of fat. 

 From dried fibrin of healthy human blood, Nasse obtained near 5 per cent, 

 of fat, and still more from the fibrin of buffy blood. The proportion of 

 fibrin in the blood does not exceed 2^ parts in 1000 ; indeed, according to 

 the greater number of observers, it is not more than 2J-. As a general rule, 

 the quantity is somewhat greater in arterial than in venous blood, and it is 

 increased in certain states of the body, especially in inflammatory diseases 

 and in pregnancy. Nasse thinks that the whole fibrin cannot be separated 



* For an account of Schmidt's method, see Lehmann's Physiological Chemistry 

 (Cavendish Society's Translation), vol. ii. 



