24 ORGANISED FLUIDS. 



that this occurrence is far less unfrequent than is generally 

 supposed, and that for each discovered case, a hundred occur 

 in which the fatal mistake is never brought to light, it being 

 buried with the victim of either ignorance or carelessness.* 



We have now to proceed to the anatomical consideration 

 of the blood : we have to pass to the description of the solid 

 constituents of that fluid, the globules; to describe their 

 different kinds, their form, tlieir dimensions and their struc- 

 ture ; their origin, their development, and their destination 

 their properties, and their uses. 



THE GLOBULES OF THE BLOOD. 



The blood is not an homogeneous fluid, but holds in sus- 

 pension throughout its substance a number of solid particles, 

 termed globules. These serve to indicate to the eye the 

 motion of the blood ; and were it not for their presence, we 

 should be unable to establish, microscopically, the fact of the 

 existence of a circulation, to mark its course, and to estimate 

 the relative speed of the current in arteries and veins under 

 different circumstances. 



These globules are so abundant in the blood, that a single 

 drop contains very many thousands of them, and yet they 

 are not so minute but that their form, size, and structure, 

 with good microscopes, can be clearly ascertained and defined. 

 They are not all of one kind, but three different descriptions 

 have been detected the red globules, the white, and certain 

 smaller particles, termed molecules. We shall take each of 

 them in order; and notice, in the first place, the red glo- 

 bules, f 



* The coagulation of the blood may be retarded or altogether prevented 

 by its admixture with various saline matters : to this point we shall huve 

 occasion to refer more fully hereafter. 



f Malpighi first signalised the existence of the red globules in the blood, 

 so far back as 1665 : he regarded them as of an oily nature. The words 

 in which this discovery was recorded were as follow : " Sanguineum 

 nempe vas in omento hystricis ... in quo globuli pinguedinis propria 

 figura terminati rubescentes et corallorum rubrorum vulgo coronam 



