184 CHEMICAL RESEARCHES ON THE ANIMAL FLUIDS. 



Alumine does '• Some pure aluniine was added to a concentrated aqueous 



not form a. solution of the colouring mattei of the blood, and after twenty- 



wiih it. ^°"'' ^ours, the mixture, which had been frequently agitated 



during that period, was poured upon a filter, and the residuum 



washed with hot distilled water. 



The filtr^-Jed liquor had lost much of its original colour j 

 ^ the alumine had acquired a red tinge ; it was dried at a tem- 

 perature between 70° and 80°, during which it became brown. 

 2. Two hundred grains of alum were dissolved in four 

 fluid ounces of a solution of the colouring matter, similar to 

 that employed in the last experiment. The colour of the com- 

 pound was bright red. Liquid ammonia was added, and the 

 precipitate collected, and carefully dried. It was ot a dirty 

 red, and after some days exposure to light, became nearly 

 brown. 



From these, and other experiments, which I have not thought 

 it necessary to detail, it appears that alumine will not form a 

 permanent red compound with the colouring principle of the 

 blood ; I was therefore next induced to employ oxide of tin. 

 Muriate of tin 3. Fifty grains of crystallized muriate of tin (prepared by 

 comb)nedwith boiling tin filings in muriatic acid, and evaporating the 

 ' solution) were dissolved in four ounces of the solution of 



colouring matter, which immediately assumed a purple tint, 

 and became afterward brown. It was diluted with twice its 

 bulk of water, and put aside in a stopped phial. On examin- 

 ing it three days afterward, a small quantity of a bright red 

 powder was observed at the bottom of the phial, which proved 

 to consist of the colouring principle combined with the metallic 

 oxide, A portion of this compound, which has been kept in 

 water for some weeks, has undergone no change of colour ; but 

 when dried by exposure to air, it loses its brilliant tint, and be- 

 comes of a dull red hue, 

 and the acid To a compound solution of muriate of tin and colouring 

 separated. matter, similar to that employed in the last experiment, I 

 added a sufficient quantity of solution of pot sh to decompose 

 the salt of tin. The precipitate thus obtained was collected, 

 and dried by exposure to the air of a warm room. It was of 

 a dull red colour, and has undergone no apparent change by 

 exposure to the joint action of light and air for three weeks. 



4. Find- 



