BEAIN. 85 



assumes a bright red colour, and evolves carbonic 

 anhydride. Identify the latter by passing it through 

 solution of baryta or lime. 



26. Shake some oxydised red blood with carbonic 

 oxyde, and observe that the latter gas is absorbed 

 while oxygen is expelled. Shake some oxydised blood 

 with carbonic acid, and observe that some oxygen is 

 expelled and carbonic acid absorbed, while the blood 

 assumes a dark red-purple colour. 



27. Expose blood enclosed in a piece of sheep's 

 gut to chlorine gas, and observe that the red colour of 

 blood passes into green. 



28. Expose blood so enclosed to a mixture of 

 ammonia and sulphide of ammonium gas, and observe 

 its decomposition and dark discoloration. 



Brain. 1. Free the brain-tissue from blood by 

 injecting water into the blood-vessels while in the 

 cranium, or after removal, and separate the mem- 

 branes. Ascertain the specific gravity of the white 

 matter to be about 1041, that of the gray matter 

 about 1034. 



2. Dry gray matter in a water bath and ascertain 

 loss of water to be from 75 to 88 %, and the re- 

 maining solids to amount to 25 to 14 % ; whereas 

 white matter will lose less than 75 % of water, 

 generally about 71 per cent., and leave 25 to 29 % of 

 solids. 



3. Extract cerebric acid with hot ether, as directed 

 under Cerebric acid, 



