APPEKDIX TO THE DISEASES OF THE SPLEEN. 



WE do not propose to treat of leuchaemia and melanaemia, in the 

 second volume, among diseases of the blood, but to class them among 

 diseases of the spleen, as they generally depend on affections of that 

 organ. But, as there are also cases of leuchsemia, and even, some of 

 melanaemia, where the blood-affection cannot be referred to disease of 

 the spleen, these affections must be described in an appendix. 



CHAPTER I. 



LEUCHAEMIA (LETTCOCYTH^EMIA Bennett). 



ETIOLOGY. A temporary increase of the colorless corpuscles of 

 the blood takes place in a number of physiological and pathological 

 conditions, as during pregnancy, inflammatory diseases, or after great 

 loss of blood. This variation of the blood from its normal state is no 

 more an independent disease than hyperinosis and hypnosis, anaemia, 

 or hydraemia, but it is the result of various states. 



The case is different with leuchaemia. This very interesting dis- 

 ease is defined by Virchow as a " change in the constitution of the 

 tissue of the blood," the blood being classed among the tissues ; in it 

 white corpuscles are to a great extent formed instead of red ones, so 

 that the number of the former increases, while that of the latter dimin- 

 ishes. We found our description on the classical work of Virchow, 

 who has shown that leuchaemia may depend either on disease of the 

 spleen, or of the lymphatic glands, and that there are two forms of 

 leuchaemia, the splenic and lymphatic. The changes of the spleen in 

 the former, and of the lymphatic glands in the latter, consist chiefly in 

 an increase of the cellular elements composing the pulp of the spleen, 

 or filling the cells of the lymphatic glands. 



Since in leuchaemia we find the blood loaded with the elements, 

 whose accumulation in the spleen and lymphatic glands causes the 

 swelling of these organs, it would appear that the leuchaemic tumors 



