;6 



THE BLOOD. 



By heat, mineral and other acids, alkalies, etc., haemo- 



Fig. 28. ; 



globin is decomposed 

 into an albuminous 

 matter (resembling 

 globulin) and liama- 

 tin. The latter, now 

 known to be a pro- 

 duct of the decom- 

 position of haemo- 

 globin, was once 

 thought to be the 

 natural colouring 

 matter of the blood. 



The Wliite Corpuscles of the Blood or Blood Leucocytes. 



The white corpuscles are much less numerous than the 

 red. On an average, in health, there may be one white 

 to 400 or 500 red corpuscles ; but in disease, the propor- 

 tion is often as high as one to ten, and sometimes even 

 much higher. 



In health, the proportion varies considerably even in 

 the course of the same day. The variations appear to 

 depend chiefly on the amount and probably also on the 

 kind of food taken ; the number of leucocytes being very 

 considerably increased by a meal, and diminished again on 

 fasting. 



They present greater diversities of form than the red 

 ones do ; but the gradations between the extreme forms 

 are so regular, that no suflicient reason can be found for 

 supposing that there is in healthy blood more than one 

 species of white corpuscles. In their most general appear- 



* Fig. 28. Hexagonal crystals from blood of squirrel. On these 

 six-sided plates, prismatic crystals, grouped in a stellate manner, not 

 imfrecjuently occur (after Funke). 



