434 Dr. Norris on the Aggregation of Blood- corpuscles, [May 27, 



which water will not mix, such as oil of turpentine or petroleum, they will 

 run together in piles or rouleaux, very much in the same way as the 

 blood-disks. 



To understand this result, a few simple primary principles must be 

 called to mind. In the first place, the particles which compose any liquid 

 have a mutual attraction for each other ; but between the particles which 

 compose different liquids a mutual repulsion may exist, e. g. water and oil, 

 or chloroform and water. It is likewise true that there is a mutual attrac- 

 tion between certain liquid and rigid bodies, and also a mutual repulsion 

 between others. Any rigid body which can be wetted by a liquid is re- 

 garded as having a cohesive attraction for it, while one which cannot be 

 wetted is said to have no such attraction, or to exert a repulsive influence, 

 as the case may be. 



These phenomena therefore depend upon what might be justly termed 

 double cohesion — cohesion in the first place between the rigid body and 

 the liquid, and in the second place between the particles of the liquid 

 itself. 



If, now, we examine into the cases in which we have complete sub- 

 mergence, viz. the blood-rolls, the gelatine disks, and the loaded cork disks, 

 we find the same law to be in operation. These bodies must all be regarded 

 as localizers of liquids, either by their cohesive attraction for liquids, or, as 

 in the case of the blood-corpuscles, by being receptacles containing liquids. 



If the cork disks, bubbles, or other bodies are entirely submerged in 

 water, all attraction ceases, and this because a cohesive equilibrium is 

 established ; there is no longer any differentiation such as exists between 

 water and air. If, however, after having wetted these bodies in water, we 

 completely submerge them in a liquid which has a cohesive antagonism to 

 water, or even a liquid which has simply no cohesion for water, which may 

 be known by the insolubility and immiscibility of one liquid in the other, 

 such as turpentine or petroleum, we get the phenomena of attraction pre- 

 cisely as in the atmosphere. This fact is illustrated by taking the cork 

 disks from the water in which they are non-adherent, and placing them in 

 the vessel of petroleum, in which they become instantly attractive of each 

 other. 



This principle is further illustrated by the gelatine disks, which are first 

 made to absorb as much water as possible, and are then submerged in 

 petroleum. 



In all these cases there are present, therefore, two dissimilar or antago- 

 nistic liquids ; and upon the presence of these the phenomena depend. 



My idea of the blood-corpuscle is that its contents are something essen- 

 tially different, so far as cohesive attraction is concerned, from the liquor 

 sanguinis — that is to say, not'readily miscible with liquor sanguinis. This 

 is of course self-evident, if, according to some modern views, we regard the 

 corpuscles " as tiny lumps of a uniformly viscous matter," inasmuch as 

 such matter must be insoluble in and immiscible with the liquor sanguinis. 



