378 PROFESSOR ARTHUR BOETTCHER. 



takes place in about twenty-four hours, but the process can be 

 much accelerated by renewing the solution of corrosive sublimate. 

 1 preferred, however, before submitting the blood-corpuscles to 

 further operations for the purpose of histological investigation, 

 to leave them in the solution of corrosive sublimate for forty- 

 eight hours. 



At the expiration of this time the latter is decanted from the 

 sediment, which has a grey appearance, and is replaced by pure 

 alcohol. The blood-corpuscles having been thoroughly washed 

 with this by agitation, are allowed to remain in it for at least 

 twenty-four hours. The alcohol is then simply decanted and 

 replaced by water. 



The blood-corpuscles which sink to the bottom now represent 

 a white mass, which has a slight tinge of grey and somewhat the 

 appearance of pus. They have entirely lost their colouring matter, 

 and have become so capable of resistance that they are no longer 

 acted on by water. I have let them stand in it for eight days or 

 more without being able to notice any change in them. 



The subsequent treatment with water offers many advantages 

 for the microscopical examination of the blood-corpuscles, and is 

 of especial service, when artificial staining is undertaken, if for 

 that purpose alcoholic solutions of the colouring matters are not 

 used. 



The structural relations, which will be immediately considered, 

 are already partly visible in the decolourised blood-corpuscles. 

 They stand out more clearly, however, after artificial staining, 

 for which purpose I have employed chiefly carmine, but also 

 eosine, hsematoxylin, and picric acid. All these colouring matters 

 are available ; the carmine, however, allows the different com- 

 ponents of the blood-corpuscles to be most easily recognised by 

 means of the various shades of colour. 



The blood-corpuscles now about to be described were treated 

 according to the method given above. 



I. The Red Blood-corpn8cles of 3Ian. 



Whereas these, in the fresh state, as is well known, strongly 

 resemble one another, after having been in the alcoholic solution 

 of corrosive sublimate, and being thus deprived of their colouring 

 matter, they appear extremely varied, and present great differ- 

 ence in regard to their composition. They may, however, be 

 divided into the following distinct classes : 



1. Blood-corpuscles which appear homogeneous and shining 

 (Fig. 1). 



These do not usually collect in heaps, but swim about free in 

 the fluid. Their shape is generally changed in a remarkable 

 manner. Their form, namely, as a rule, is not even tolerably 



