LEUCOCYTOSIS AND LEUK^M.A. 201 



of one, and now of another, kind in the lymphatic glands, 

 but do not produce any local exudation of fibrine. Thus 

 typhoid fever causes these changes not only in the spleen, 

 but also in the mesenteric glands. 



The condition in which the increased proportion of 

 colourless corpuscles in the blood appears to be depend- 

 ent upon an affection of the lymphatic glands, I have de- 

 signated by the name of Leucocytosis. Now you know 

 that another matter has long been the subject of my stu- 

 dies, the affection named by me Leukcemia, and our next 

 business must be to determine how far genuine leukae- 

 mia differs from these leucocytotical conditions. In the 

 very first cases of leukaemia which came before me, a very 

 essential property was discovered to exist, namely, that 

 there was no essential variation in the proportion of 

 fibrine in the blood. Afterwards itwas found out that 

 the proportion of fibrine might, according to the parti- 

 cular circumstances of the case, be greater or less than, 

 or the same as, usual, but that a continually augmenting 

 increase of the colourless blood-corpuscles invariably took 

 place ; and that the coincidence of this increase with a 

 diminution in the number of the coloured (red) corpus- 

 cles became more and more marked, so that as a final 

 result a condition was attained, in which the number of 

 the colourless corpuscles was almost equal to that of the 

 red ones, and striking phenomena were displayed, even 

 when the coarser modes of observation were employed. 

 Whilst in ordinary blood we can seldom count more than 

 one colourless corpuscle to about three hundred coloured 

 ones, there are cases of leukaemia in which the increase 

 of the colourless ones reaches such a height, that to every 

 three red corpuscles there is one colourless one, or even 

 two ; or in which indeed the greater numbers are in 

 favour of the colourless corpuscles. 



In dead bodies the increase in the colourless corpus- 



