1813.] o.nd some other Animals. 33^ 



To dry this oil after washing it, we may expose it for softie 

 time to the open air, or to a gentle heat. 



Let us examine the properties of this matter thus purified^ 

 leaving to another section the examination of the water frbtti 

 which it has been separated. 



1. It has a reddish brown colourj an odonr sfimilar to that of 

 the brain itself, but stronger. Hence it is probably this sub 

 stance which gives its peculiar odour to the brain. 



2. Its taste is similar to that of rancid fat. 



3. When agitated with cold water it mixes with tliat liquid, 

 and forms a sort of homogeneous emulsion, which separates 

 dnly v6ry slowly. The mineral acids, mixed in a certain quan- 

 tity with this emulsion, immediately precipitate an oily matter, 

 under the form of white opake flocks; and the liquor then 

 passes clear through the filter, which was not the' case before. 

 The muriatic acid which has thus served to coagulate this species 

 of emulsion, lets fall very light white flocks, when mixed %itli 

 ammonia ; but when nitric acid is employed, it neither can be: 

 made to precipitate by ammonia nor lime-water. 



The infusion of nutgalls likewise coagulates this emulsion. 



4. If the water be decanted off as soon as the fatty matter 

 is deposited, and it be left to itself, it putrifies, and exhales ^ 

 fetid odour, indicating the presence of an aninfial matter. 



5. It dissolves in hot alcohol, some light flocks excepted, 

 which do not amount to the hundredth part of it. The greatest 

 part of it separates from the alcohol when it cools, and renders 

 it milky, as would happen to a solution of resin. 



6. Exposed on burning coals it melts, blackens, swells up, 

 and emits an odour of burning animal matter^ and afterwards 

 that of greaselin the state of vapour. 



7. When burnt in a platinum crucible, either alone or mixed 

 with potash or nitrate of potash, it always furnishes phosphorid 

 acid, either uncombined or combined with the alkali, according 

 to the process ; just as happens to the fatty matter deposited 

 from the alcohol during its cooling. Hence we must form the 

 same opinion respecting the origin of this acid. We must admit 

 the presence of phosphorus in the fatty matter. 



From 400 grammes of brain employed in this process we have 

 obtained about 3 gram meg of this matter, which amounts to 

 about 0-75 of a gramme per cent. 



We ought now to inquire in what this substance differs from 

 that which falls spontaneously from the alcohol during its cool* 

 ing, the properties of which have been already described. 



Though it remains in solution in the cold alcohol, it is not 

 very soluble in that liquid; for when alcohol^ at a boiHiig 

 temperature, is saturated with it, a portion is deposited, as the 

 alcohol cools, in the f6rn> of flocks. In this sespect it approacto 



y 2 



