EXTRACTIVE MATTERS. 31 



For the purpose of tlioroiiglily examining tlie extract of flesh 

 in all its chemical bearings, Simon experimented on eight 

 pounds of the thickest part of a leg of pork, which he freed as 

 much as possible from sinew, fat, cellular tissue, and every- 

 thing that was not absolutely muscular flesh. It was then cut 

 in small pieces, and cold water was poured over it. After being 

 allowed to stand in water for some time, it was removed and 

 boiled three successive times in fresh water. These boilings were 

 collected, and a little fat skimmed oft'. The cold water in which 

 it was first placed, was then boiled and mixed with the rest. 

 The whole was then filtered, and appeared as a light yellow 

 fluid, with a strong smell and taste of broth. This fluid was 

 evaporated to the consistence of a thin syrup. After cooling, it 

 did not gelatinize, and contained no glutin, or at most, a mere 

 trace. 



Alcohol was added to this thin syrup, imtil all the constituents 

 insoluble in spirit, appeared to have separated, and deposited 

 themselves at the bottom. 



We thus separate the extractive matter into two distinct 

 parts, one, soluble in water, but not in dilute alcohol, the other 

 soluble in the latter menstruum. 



The former, when evaporated at a gentle temperature is of 

 a brownish yellow coloiu', and is tolerably firm, tenacious, and 

 tough ; it is termed water-extract. 



The latter must be evaporated to the consistence of an 

 extract, and treated with from twelve to sixteen times its 

 volume of absolute alcohol. The mixture must then be heated, 

 and well shaken, so as to mix the alcohol with the deposited 

 portion as thoroughly as possible. The alcoholic solution clears 

 on standing, and assumes a yellow colour. It must be 

 removed from the insoluble residue, and gently evaporated to 

 a clear brown syrup, which after cooling and standing for 

 some time assumes a solid form ; it dissolves freely both in 

 water and absolute alcohol. By repeatedly treating the 

 insoluble residue with hot absolute alcohol we remove all that 

 is soluble in that fluid, and there is left a tolerably firm, tough, 

 brown extract, which is soluble only in aqueous alcohol, and to 

 Avhicli the term spirit-extract is given. We distinguish the 

 portion which is soluble in absolute alcohol Isy the term alcohol- 

 extract. 



