226 ELEMENTARY PHYSIOLOGY. [XXI. 



I. Add drop by drop HC1 1 p.c., the haemo- 

 globin will be split up and the proteid 

 constituent precipitated ; add an equal bulk 

 of ether and shake, the colouring matter 

 (haamatin) will be largely dissolved in the 

 acid-ether ; with a pipette remove the lower 

 stratum of fluid, add a few drops more acid 

 and place at about 40 C., the proteid precipi- 

 tate will be converted into acid-albumin and 

 dissolved ; neutralize, it will be precipitated 

 and may be examined for the ordinary cha- 

 racters of acid-albumin. 



11. Place a drop of blood on a glass slide, and by 

 gently warming evaporate it to dryness : add to 

 it a grain of salt, and thoroughly mix it with the 

 blood, rubbing the whole to a fine powder. 

 Cover with a cover-slip, and let a little glacial 

 acetic acid run under it. Warm the slide, not 

 too rapidly, over a flame till bubbles appear 

 under the cover-slip ; then let it cool, and ex- 

 amine under a microscope with a high power. 

 A large number of crystals of haemin as 

 brown-red rhombic prisms will be seen. 



DEMONSTRATIONS. 



1. The spectra of 



a. Hsematin in acid and alkaline solutions. 



b. Hasmatin reduced in an alkaline solution. 



2. The gases of the blood. 



