BLOOD. 175 



as is sufficient to precipitate the dissolved hsematoglobulin in 

 distinct flocks. If the whole is now allowed to stand for 12 — 18 

 hours, all these flocks will be deposited at the bottom of the 

 vessel, and there will remain above them a clear yellow fluid, 

 which must be removed Avith a syphon, and the last remaining 

 portion with a pipette. The flocks must be washed two or three 

 times with fresh spirit of from '89 to "90, which must be re- 

 moved by the same means. 



If these spirituous solutions are of a yellow or citron colour, 

 we may assume that they contain only salts and extractive 

 matters tinged ^vitli htemaphaein : if they are of a reddish tint, 

 then hsematoglobulin is also present, which must be precipitated 

 by the addition of stronger spirit. 



We have now to analyse (i) the flocculi, and (ii) the spi- 

 rituous solution. 



I. a. One or two ounces of alcohol of -83 or -80 (the 

 stronger the better) are poured over the flocks ; the mixture is 

 then well stii-red, and a sufficient quantity (usually from three 

 to eight drops) of dilute sulphuric acid is added (juttatim, until 

 a decided change of colour of the flocks is observed. The flocks 

 are now allowed to settle, and the deep red alcoholic solution is 

 decanted. The decolorized flocks are then treated Avith pure 

 alcohol until they cease to give ofli" any more colouring matter. 

 If, after this, the flocks have still a reddish tinge, they must be 

 treated with a httle more acidulated alcohol. If the flocks are 

 as free from hsematin as possible, they assume a more or less 

 clearly defined gray colour ; when dried, they appear as a dirty- 

 gray powder, and on incineration they leave a yellow or orange- 

 coloured ash. 



b. The flocks must be washed with alcohol until they 

 cease to exhibit an acid reaction ; they must then be washed 

 out of the glass flask (with the aid of a feather and a little 

 water) into a porcelain basin, be diied first upon the water- 

 bath, and subsequently at a temperature of 230", and then 

 weighed. They are estimated as globulin. 



c. The red alcoholic solutions are mixed and saturated 

 with ammonia to such an extent as to emit a decided ammo- 

 niacal odour; they are allowed to stand for some hours, in 

 order to allow of the separation of the sulphate of ammonia ; 



