16 THE BLOOD. 



This liquid, entirely free from anatomical elements, was enclosed in little sacs formed 

 of an animal membrane (gold-beater's skin) and introduced under the skin of a living 

 rabbit. At the end of twelve hours, a few small leucocytes and granulations had made 

 their appearance ; at the end of twenty-four hours, the fluid had become somewhat 

 opaque, and contained a large number of leucocytes and granulations ; and, at the end 

 of thirty-six hours, the fluid was white, milky, and composed almost entirely of leucocytes 

 and granulations. The leucocytes, which were examined also by Prof. Kobin, presented 

 all the characters by which these corpuscles are ordinarily recognized. These experi- 

 ments were repeated with more than forty different specimens of fluid from blisters. 



The experiments were then varied in order to show the influence of the membrane 

 and the composition of the blastema upon the development of leucocytes. By modify- 

 ing the membrane in which the blastema was enclosed, it was found that the corpuscles 

 were rapidly developed in proportion to the activity of the osmotic action. When thick 

 animal membranes were used, their development was slow, and, in some instances, did 

 not take place at all. There was no development of leucocytes in a clear blastema en- 

 closed in a sac of caoutchouc or in glass tubes hermetically sealed ; and from this it was 

 concluded that osmotic action is a necessary condition, and that the mere heat of the 

 body is not sufficient to develop these corpuscles, even in an appropriate blastema. The 

 influence of this constant molecular movement is in striking contrast to the conditions 

 of absolute repose which are so essential to the formation of crystals from ordinary 

 saline solutions. 



One of the most interesting points in these experiments is connected with the influ- 

 ence of the composition of the blastema upon the development of leucocytes. It was 

 found that these bodies were never developed in a blastema in which the fibrin had been 

 coagulated. Experimenting with two liquids, the only difference in their constitution 

 being that in one the fibrin had been coagulated by repeatedly plunging the glass tube in 

 which it was contained into cool water, while the other was kept at the ordinary tem- 

 perature, a little bicarbonate of soda being added to prevent coagulation, it was found 

 that leucocytes were developed as usual in the fluid which contained the fibrinous elements, 

 and that none appeared in the other. On placing the liquid with its coagulum enclosed 

 in a sac under the skin, it was found that, after a time, the fibrin was redissolved, but 

 no leucocytes made their appearance. 



The theory which has for its motto, omnis cellula e cellula, receives no support from 

 these experiments. Onimus added to fluids which had been deprived of fibrinous matters, 

 epithelial cells and pus-corpuscles, but, even after thirty-six hours, he never found any 

 additional development of corpuscular elements. Leucocytes added to fluids in which 

 the fibrinous elements were unchanged did not seem to exert any influence upon the de- 

 velopment of new corpuscles. 



Elementary Corpuscles. Little granules are found in the blood, especially during 

 digestion, which, as they were supposed to take part in the formation of the white cor- 

 puscles, have been called elementary granules or corpuscles. They probably are little 

 fatty particles of the chyle which come from the thoracic duct, and are not positively 

 known to have any connection with the formation of the other corpuscular elements of 

 the blood. 



Composition of the Red Corpuscles. 



The red corpuscles of the blood contain an organic nitrogenized principle, called 

 globuline, combined with inorganic principles and a coloring matter. The composition 

 of the leucocytes has not been accurately determined. The inorganic matters contained 

 in the red corpuscles are in a condition of intimate union with the other constituents. 

 and can only be separated by incineration. It may be stated, in general terms, that 

 most, if not all of the various inorganic constituents of the plasma exist also in the cor- 



