266 BLOOD 



men ted at this period. From the 9th day of the disease the 

 constitution of the blood assumes a totally different character ; for 

 at this period the blood becomes lighter, chiefly owing to a dimi- 

 nution of the corpuscles ; the residue of the serum, however, dimi- 

 nishes daily through the entire duration of the disease, with a rapidity 

 proportional to the intensity of the intestinal affection. The salts 

 and extractive matters are relatively increased, rather than abso- 

 lutely diminished. If typhus be not followed by any of its frequent 

 sequelae, or by the anaemia accompanying many of the epidemic 

 forms of this disease, there is generally found to be an increase of 

 the solid constituents about the beginning of the fourth or fifth 

 week, which in some cases chiefly affects the blood- corpuscles, in 

 others the solid substances of the serum, while occasionally even 

 the quantity of the fibrin is augmented. 



In acute exanthemata., there is a diminution of the blood-cells 

 and a corresponding augmentation of the intercellular fluid. The 

 serum is denser than usual, and its salts are far more augmented 

 than the organic substances. 



In puerperal fever ', the blood varies according to the course and 

 character of the morbid process (as indeed we observe in most cases 

 of disease). There is a very considerable diminution of the cor- 

 puscles; the fibrin, especially in peritonitis, is much increased, but 

 is soft and gelatinous, and almost always forms a crust. In most 

 cases the solid constituents of the serum are considerably dimi- 

 nished (Scherer, Becquerel and Rodier); but sometimes they are 

 increased (Andral and Gavarret) ; the extractive matters are con- 

 siderably increased (Scherer) ; bile-pigment is occasionally met 

 with (Heller) ; and not unfrequently free lactic acid (Scherer.) 



In py&mia, the fibrin is diminished, and the colourless blood- 

 cells augmented ; but more than this is not known, as the blood 

 has not been carefully examined in this disease. 



The blood has not been examined with accuracy in scurvy, and 

 its composition has therefore been deduced principally from phy- 

 sical relations ; thus, for instance, its imperfect coagulation led to 

 the conclusion that it exhibited a diminution of fibrin, while other 

 causes led in the same manner to the supposition that there was 

 an augmentation of the salts. The few investigations of scorbutic 

 blood which we possess, give but little idea of the true constitution 

 of this fluid in the condition which we term scurvy. 



The admixture of the blood in tuberculosis does not seem to 

 differ greatly from the normal condition, for the modifications 

 which it undergoes, appear, as far as our chemical investigations 



