CHAP. III.] THE BLOOD IN DISEASE. 163 



The pigment is considered to be altered haematin, and, ac- 

 cording to the older view (Frerichs, Virchow), its presence in the 

 blood is due to a breaking up of the red blood-corpuscles in the 

 spleen and liver. According to Arnstein, however, the pigment 

 originates in the blood itself, from the destruction of the red blood- 

 corpuscles during the attack of fever, and penetrating into the 

 leucocytes of the circulating blood becomes deposited along with 

 them in the spleen, liver and medulla of bone 1 . 



The formation of black pigment has lately been observed going 

 on within the coloured corpuscles by Marchiafava 2 , whose observations 

 have been confirmed by Klebs and Tommasi-Crudeli ; in the process, 

 iron is set free from the state in which it exists in haemoglobin, so 

 that when the corpuscles which have become black are treated with 

 dilute hydrochloric acid and potassium ferrocyanide they acquire a 

 blue colour. 



Scarlet Fever, Measles, Small-pox, Erysipelas. 



In the first of the above diseases there is primarily no alteration 

 in the proportion of blood constituents. In scarlet fever, however, 

 when kidney complications set in, there is a tendency to accumu- 

 lation of urea in the blood, which often attains a high degree, and 

 subsequently a great diminution of the proteids of the blood occurs. 



In small-pox, coincident with the inflammatory changes in the 

 skin, there occurs a moderate increase in the amount of fibrin. 



In erysipelas, the blood at first presents in a characteristic manner 

 the appearances which i't always assumes when an acute inflamma- 

 tory process involves an organ of any magnitude, t>r implicates any 

 considerable extent of one of the tissues ; the blood, in consequence, 

 yields much fibrin. There is, however, no other constant alteration, 

 unless there be any truth in the very doubtful statement of Schonlein 3 

 that the serum which separates from the blood, in erysipelas, is always 

 tinged yellow by the colouring matter of bile. 



The Blood in Cholera. 



A very elaborate investigation into the changes which blood 

 undergoes in cholera was made by Professor Carl Schmidt 4 during the 

 epidemic of that disease which ravaged Dorpat in the summer and 

 autumn of 1848. 



In consequence of the very great transudation of water and 

 albumin from the alimentary canal, the blood in cholera becomes 

 excessively poor in water and relatively rich in solid constituents, so 



1 Virch. Arch. Vol. LXI. p. 494. 



2 Marchiafava, " Commentario clinico di Pisa. Fascicolo del gennaio 1879. Quoted 

 by Klebs and Tommasi-Crudeli, op. cit. p. 57. 



3 Schonlein, quoted by Simon, Animal Chemistry, Vol. I., p. 278. 



4 Carl Schmidt, " Charakteristik der epidemischen Cholera gegenuber verwandten 

 Transudationsanomalien." Leipzig und Mitau, 1850. 



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