BLOOD. 209 



posit themselves and form a dark coagulated clotted mass under 

 the sm'facc of the serum, from which no additional fi])rin can 

 be obtained by further stirring; and upon allowing it to rest, 

 the same phenomena are again exhibited. On placing a little 

 of the blood, immediately after stirring, on a glass slip, the 

 blood-corpuscles may be seen to collect into minute islets or 

 spots ; at least I observed this to occur in three specimens of 

 this sort of blood that I analysed at different times. 



In one instance I found that the Idood had actually coagu- 

 lated, but slowty, after the removal of fibrin by whipping, and 

 upon renewed stii-riug I obtained a small quantity of stringy 

 or coriaceous fibrin. 



Microscopic anahjsis. On examining a specimen of this 

 blood, not diluted with the ordinary solution of salt, the swollen 

 corpuscles were observed moving about; some were distinct, 

 some partially united with others; these gradually attached 

 themselves to one another and formed irregular groups of various 

 sizes, in which the outlines of the individual corpuscles could 

 no longer be recognized. It appeared as if the corpuscles 

 exuded a plastic matter, which might possibly be the ciiuse of 

 their adhering to each other. 



On diluting the blood with a solution of hydrochlorate of 

 ammonia, I once observed that the medium-sized corpuscles 

 appeared studded with minute pearly beads, (vide supra, page 

 105.) The following observation which I made upon two 

 occasions interested me extremely. I saw a great excess of 

 small blood-corpuscles, about one fourth or one sixth of the 

 ordinary size, whose true natui'e could only be recognized 

 by their well-marked yellow colour, and by their passing from 

 a spherical into a flattened form, when rotation was excited. 

 The motions of these minute blood-corpuscles resembled those 

 of Brown^s molecules, and were much more active than those 

 of the ordinary corpuscles in common blood. 



The analysis of the blood of the hepatic vein gave in 1000 

 parts — 



14 



