ITS COMPOSITION. 227 



that such scanty materials could aid us in obtaining any insight into 

 the obscure mysteries of morbid processes. We will riot deny that 

 thanks are due to those who have prosecuted the most compre- 

 hensive investigations with minute carefulness and disinterested 

 labour; but we should be untrue to the cause of science, did we 

 fail to set forth the real character of these results. 



We have already attempted, at the beginning of this chapter 

 (see page 160), to give a general view of the quantitative composition 

 of the blood ; and we will now proceed to consider the varying pro- 

 portions of the individual constituents under different physiological 

 and pathological conditions. 



The ratio of the blood-cells (in the morphological sense) to 

 the intercellular fluid, appears to undergo very slight fluctuations 

 in the normal state when the physiological conditions are analo- 

 gous. In an adult healthy man, we find on an average 512 parts 

 of moist blood-corpuscles in 1000 parts of blood ; the fluctuations 

 do not exceed a difference of more than 40 in either extreme, so 

 that while 472 would be a very low number, 552 would be a very 

 high one for the proportion of cells in the blood of a man. 



According to the above described method, the dry blood- 

 corpuscles found by Prevost and Dumas, amounted to 129 p.m., 

 by Lecanu* to 132-5, by Andral and Gavarretf to 127, by 

 Richardson^ to 134'8, by Becquerel and Rodier to 141-1, by 

 Nasse|| to 116'5, by Popp^f to 120, and by Scherer** to only 112. 



It is scarcely necessary to observe that no conclusion regarding 

 the proportion of the cells to the plasma can be drawn from the 

 proportion of the serum to the clot : as we have already seen in the 

 preceding remarks the sinking capacity of the blood-corpuscles on 

 the one hand, and the contractility of the fibrin on the other, present 

 such variations that we may readily comprehend how one volu- 

 minous clot may contain very few blood-corpuscles, whilst another 

 which is less voluminous may contain a proportionally larger 

 number of cells. 



In the blood of women we find on an average fewer cells 

 than in that of men ; their number is still more decreased during 



* Etudes chimiques sur le sang humain. Paris, 1 837. 



t Recherches sur les modifications de quelques principes de sang, &c. 

 Paris, 1842. 



t Thomson's Record of General Science, vol. iv., pp. 116135. 

 Recherches sur la composition du sang, &c. Paris, 1844. 

 II Op. cit. 

 ^1 Op. cit. 



** Op. cit. 



Q2 



