1835. Lymph, Blood, and Chyle. 429 



In blood extracted from men and cats, half an hour scarcely 

 elapses before the globules sink 4 or 6 lines beneath the 

 surface of the serum, while in that from oxen and sheep 

 an interval of 12 or 24 hours occurs before the globules 

 have subsided a line and a half. 



If water, however, is added to blood extracted from mam- 

 malia, a portion of the colouring matter dissolves in that 

 liquid, and a great proportion of the globules sinks to the 

 bottom. In the blood of the frog the globules sink so 

 rapidly that it is necessary to stir up the coagulum in order 

 to have the globules mixed with the serum for the purposes 

 of examination. When water is added to a mixture of 

 serum and globules, and agitation employed, the colouring 

 matter of the globules dissolves, and a light coloured preci- 

 pitate falls to the bottom of the vessel, which appears under 

 the microscope to consist of roundish globules, much smaller 

 than those of the blood. This residue, from the action of 

 water, is soluble in alkalies, but insoluble in acetic acid. 



That the colouring matter of the globules is completely 

 soluble in water, and is not suspended in that liquid, may 

 be easily demonstrated, not only in human blood and in 

 that of mammalia, but also more readily in the blood 

 globules of the frog. Berzelius considers the insolubility 

 of colouring matter in serum to depend on the presence of 

 albumen. M tiller, although he agrees in considering the 

 colouring matter of the globules soluble in water, does not 

 attribute the insolubility of the colouring matter in serum 

 solely to the presence of albumen rendered soluble by soda, 

 but more especially to the salts of the serum. When he 

 placed under the microscope a drop of the blood of the frog, 

 mixed with a drop of a solution of the yolk of an egg in 

 water, he observed the blood globules change their form as 

 rapidly as when he employed pure water. But when a 

 drop of the same blood was joined with a solution of carbo- 

 nate of potash or common salt, the form and size of the 

 globules was not altered. 



Water renders the globules smaller than the long dia- 

 meter of the original ellipse, but larger than the broad 

 diameter. But water containing carbonate of potash, or 

 common salt, sal-ammoniac or sugar, in solution, produces 



