3*8 CUcmval Properties of Animal Fluids. [Nov. 



this opinion had often been questioned, owing to the very small 

 proportion of soda ; and lately our skilful contemporary, J he- 

 nar.!, has published an analysis of bile, in which he gives as its 

 component parts, soda, a peculiar matter named by him 

 Pieromel, and a resin, which, united, produce a fluid that has 

 the taste and other distinguishing properties ot this, secretion. 

 Nevertheless, 1 am convinced that there is no such resin as 

 Thenaro and his predecessors have described. 1 shall not here 

 relate my experiments on this supposed resin in particular, but 

 shall give the result of my inquiries on the bile itself, which will 

 enable the reader to confirm or reject my opinions, according as 

 he finds them founded on accurate experiment. 



The substance which is peculiar to bile has an excessively 

 bitter taste followed by some sweetness ; the smell is also pecu- 

 liar, and the colour in most animals varies from green to greenish 

 yellow. It is soluble in water, and its solubility is not in the 

 least promoted by the alkali of bile, since, when this is neutral- 

 ized by any acid, the peculiar matter does not separate : it also 

 dissolves in alcohol in all proportions. Like the albuminous 

 materials of the blood of which this peculiar matter is composed, 

 it will unite with acids, producing compounds of two degrees of 

 saturation, and hence, of solubility. The acetous acid, which 

 gives soluble compounds with the albumen of the blood, does 

 the same with the peculiar matter of the bile ; and hence this 

 matter is not precipitated on adding this acid to bile, though it 

 falls down on the addition of the sulphuric, nitric, or muriatic 

 acids. It is this sparingly soluble compound of biliary matter 

 with a mineral acid which has been mistaken by many chemists 

 for a resin; since it possesses the external characters of a resin, 

 melts when heated, dissolves in spirit of wine, and is again pre- 

 cipitated (in part at least) by the addition of water. The alkalies, 

 alkaline earths, and alkaline acetates, decompose and dissolve it: 

 the farmer, by depriving it of its combined acid; the latter, by 

 furnishing it with acetous acid, which renders it soluble in 

 water. 



The peculiar matter of bile will also combine with many 

 metallic oxides into a pulverulent mass ; and the above described 

 resiniform compound of this matter, and any of the mineral 

 acids, often form with the same oxides a substance like a plaster, 

 resembling in this respect also the true resins. 



The degree of insolubility possessed by these compounds of 

 2cid and biliary albumen varies both according to the species of 

 animals, and also according to the length of time that the bile 

 has been extracted ; for the longer it has been kept, the more 

 solubility these compounds acquire ; but in this case I have 

 always found that by pouring in a fresh quantity of acid, and 

 slowly evaporating the mixture, the resinous matter falls down as 

 the supernatant liquor becomes more acid. 



