536 



LIQUID PARTS OF ANIMALS. 



To determine whether it contained lactic acid, so common in 

 animal fluids, the dried extract was digested in alcohol of 0-870. 

 The alcohol, after being separated by the filter, was strongly co- 

 loured, and reacted as an acid. It was mixed with sulphuric 

 acid diluted with alcohol, which caused a crystalline precipitate 

 of sulphate of soda and potash. The filtered liquid was digested 

 with carbonate of lead, till it ceased to be precipitated by chic- 

 ride of barium. It was now distilled, after separating the lead 

 by sulphuretted hydrogen. What came over contained no acid, 

 showing the absence of acetic acid from the pus. What remain- 

 ed in the retort had the consistency of a syrup, was of a dark- 

 brown colour, and strongly reddened litmus-paper. It was di- 

 luted with water, and boiled with carbonate of zinc, as long as 

 any carbonic acid was disengaged. The excess of oxide of zinc 

 was then removed by the filter. The liquid, after being digested 

 with some animal charcoal, was evaporated, and left a crust of 

 lactate of zinc, which is exceedingly soluble in water. The 

 oxide of zinc was thrown down by carbonate of potash, the po- 

 tash by tartaric acid, and the excess of tartaric acid by carbonate 

 of lead. The lead being removed by sulphuretted hydrogen and 

 the liquid evaporated, a colourless acid syrup was obtained, pos- 

 sessing all the properties of lactic acid. 



The slimy matter not taken up by the alcohol contained fat, 

 gelatin, and some albumen. 



A portion of pus was left in contact of ether for six months. 

 It was converted into a cheesy magma, over which the yellow 

 ether floated. The ether contained in solution much yellow fat 

 of the consistence of butter. 



The present opinion of physiologists is, that the globules con- 

 stituting pus are nothing else than the globules of blood modi- 

 fied by the inflammatory process. Many experiments have been 

 made by M. Gendrin and Mr Gulliver to prove the truth of this 

 opinion.* 



II. Dr Becquerel made an imperfect analysis of pus from an 

 abscess, the result of which was as follows :f It was white, with 

 a shade of yellowish-green, opaque, very thick and viscid, and 

 having a peculiar smell. With water it formed an emulsion, 

 from which the pus precipitated very slowly to the bottom in 

 white clots. The water is clear and limpid, but it had dissolved 



* Phil. Mag. (third series), xiii. 198. t Semeiotique des Urines, p. 108. 



