BLOOD. 32 i 



THE FOURTH FORM OF DISEASED BLOOD : HETEROCHYMEUSIS.^ 



I arrange under this form all those states of the blood in 

 which a substance is present that does not exist in the normal 

 fluid : wlien^ for instance, the blood contains urea (in appreci- 

 able quantity), sugar, colouring matter of the bile, fat, or pus. 

 The circumstances that lead to the establishment of this diseased 

 condition of the blood are far less natiu'al than those which are 

 connected with the production of the three former classes. The 

 arrangement is artificial, and merely adopted for convenience, 

 since this class of diseases has simply this property in common, 

 that the composition of the blood is here qualitatively changed, 

 whilst in the three former it was only altered quantitatively. 

 The putrid form of typhus, the yellow fever, and the plague, 

 certainly might have been placed in this class, since colouring 

 matter of the bile, and a salt of ammonia, are often found in 

 the serum. I have, however, thought it best to place these dis- 

 eases in the third class, because, in the first place, the presence 

 of the abnormal constituents is not constant ; and because, se- 

 condly, in consequence of the deficiency in the solid constitu- 

 ents of the blood in these disorders, they naturally occur under 

 the class spansemia. 



I. BLOOD CONTAINING UREA: URyEMIA, 



a. Morbus Briffhtii. 



Andral and Gavarret describe the blood in this disease as 

 characterized by a deficiency of albumen in the serum. 



It is evident, however, both from my own and fromChristison's 

 researches, that the decrease of the solid constituents of the 

 serum is not always the leading character in this disease. I 

 have thought it right, therefore, to arrange this disease, on ac- 

 count of the nearly constant presence of urea in the blood, 

 under the form heterochymeusis. 



Christison,^ who has attentively studied the blood in this dis- 

 ease, describes it in the following manner : The blood in the 

 first stage of the disease coagulates with a thick, firm, and cupped 

 bufiy coat. The serum is usually rather turbid, and when shaken 



' From iripoQ and \viiivciQ. 



* Oa the Granular Degeneration of the Kidnevs, etc., hy R. Christison. Edin. 1839. 



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