184 OF THE BLOOD. 



destroyed by water than are those of the blood of most other vessels ; while in 

 the blood of the portal vein there are 141 parts of moist blood-cells to 100 

 parts of plasma, in the blood of the hepatic vein there are 317 parts of moist 

 blood-cells to 100 of plasma. The cells in the blood of the hepatic veins are 

 poorer in fat and in salts, and especially in haematin, or at least iron, but some- 

 what richer in extractive matters. The specific gravity is higher than that of 

 the cells of the portal blood, notwithstanding the diminished quantity of iron. 

 The plasma of the blood of the hepatic veins is far denser than that of the blood of 

 the portal vein, for it contains a much larger amount of solid constituents gene- 

 rally, although little or no fibrin is to be found in it (?). While 8.4 parts of 

 solid matter correspond to 100 of water in the serum of portal blood, there are 

 11.8 parts of solid matter to an equal quantity of water in the serum of the 

 blood of the hepatic veins. If we compare the solid constituents of the serum 

 of both kinds of blood, we find less albumen and fat, and far less salts, in the 

 blood of the hepatic veins, while the quantity of extractive matter, including 

 sugar, is perceptibly augmented." 1 It cannot be doubted that, when the secre- 

 tion of urine is proceeding with rapidity, the blood of the renal vein must con- 

 tain a smaller proportion of water than that of the renal artery, and that the 

 quantity of salines also must be diminished; since a separation of these ingre- 

 dients takes place in the passage of the blood through the renal capillaries. So 

 far as regards the quantity of water, this d priori conclusion has been confirmed 

 by the analyses of Simon, who found 790 parts of water in 1000 of blood 

 drawn from the renal artery, and only 778 in blood drawn from the renal vein 

 of the same animal. 2 The proportion of salts, however, has not been analyti- 

 cally determined to be different. 



170. Alterations in the Composition of the Blood in Disease. Under this 

 head it is intended here to consider, not the state of the Blood in every princi- 

 pal type of disease (which it is the duty of the Pathologist to investigate), but 

 the most important facts which the study of its morbid conditions has afforded, 

 towards the determination of the conditions under which decided variations 

 take place in the quantity or quality of its principal components, and of the 

 effects which those variations produce upon the system at large. The first series 

 of such connected researches, as afford the requisite materials for this inquiry, 

 was that of MM. Andral and Gravarret, 3 which is still cf standard value; this 

 was followed by the investigations of MM. Becquerel and Rodier; 4 and many 

 additional analyses have been made by Popp, Simon, and other observers. For 

 the purpose of comparison, however, as already remarked, it is desirable to em- 

 ploy those results only which have been obtained by processes essentially the 

 same ; and hence the following summary will be chiefly based on the statements 

 of the French experimenters whose researches have been just referred to. It is 

 necessary, however, in the first place, to assume some standard of composition, 

 which may be regarded as sufficiently characteristic of health, to lead us to rank 

 any variation which passes beyond its limits as essentially morbid; and this 

 standard must be fixed according to the method of analysis employed. Thus, 

 although it has been shown ( 154) that the calculation of the proportionals of 

 the principal constituents of the blood, from the results obtained according to 

 the method of MM. Andral and Gavarret, must be held to be in itself errone- 

 ous, yet as the same method was followed in all the analyses of morbid blood 

 made by them and their successors, the requisite standard must be erected upon 

 this foundation ; and the following may thus be considered as the normal range 



1 "Lehrbuch der Physiologischen Chemie," band ii. p. 250. 



2 "Animal Chemistry," translated by Dr. Day, vol. i. p. 214. 



3 "Essai d'Hsematologie Pathologique." 



" Recherches sur la Composition du Sang dans 1'Etat de Sante et dans 1'Etat de Maladie." 



