J_86 LECTURE VII. 



most frequently presents itself at those points where the 

 number of the bodies is normally the largest, namely in 

 the interval between the orifice of the thoracic duct, and 

 the capillaries of the lungs. The naked eye can with 

 tolerable ease detect in these clots the greater or less 

 quantity of colourless corpuscles. Under circumstances 

 inducing the presence of a very large number of them, 

 whole heaps of them may be seen, investing different 

 parts of the coagulum like a sheath, and if one of these 

 heaps be placed under the microscope, many thousands 

 of colourless corpuscles are seen crowded together. 



If the coagulation of the blood takes place, when it is 

 more at rest, another appearance is presented with great 

 distinctness, as may be seen in the vessels used to receive 

 the blood after venesection. When the fibrine does not 

 coagulate very quickly, as is the case in inflammatory 

 blood, the blood-corpuscles begin, in consequence of 

 their greater specific gravity, to sink through the fluid. 

 This subsidence proceeds, as is well known, to such a 

 pitch, that, after the fibrine has been removed by stir- 

 ring, the serum becomes perfectly clear, in consequence 

 of the corpuscles' falling to the bottom. On defibrinating 

 blood rich in colourless corpuscles, and allowing it to 

 stand, a double sediment forms, a red and a white one. 

 The red one constitutes the deeper, the white one the 

 more superficial stratum, and the latter looks exactly as 

 if a layer of pus were lying upon the blood. When the 

 blood has not been deprived of its fibrine, yet coagulates 

 slowly, the subsidence of the corpuscles does not take 

 place so completely, but only the highest part of the 

 liquor sanguinis becomes free from corpuscles ; and when 

 after this the fibrine coagulates, we obtain the well-known 

 crusta phlogistica, the buffy coat, and on looking for the 

 colourless corpuscles, we find them forming a separate 

 layer at the lower border of the bufiy coat. This pecu- 



