ON ANIMAL MATTER. 83 



animal blood, produces that effect on this concrescible part. 

 Several causes, and many different, are capable of effecting 

 this coagulation j such as contact of air, heat, alcohol, earth, 

 alum, and some of the metallic salts. The more perfect 

 neutral salts are found to prevent coagulation, such as com- 

 mon salt and nitre. 



Of the fluids secreted from the blood, there a great variety 

 in men and other animals. 



The excrementitious and redundant fluids are those which 

 afford, in general, the greatest quantity of volatile alkali, and 

 empyreumatic oil. There are, also, some of the secreted 

 fluids which, on a chemical analysis, yield products in some 

 degree peculiar to themselves. Of this kind is the urine, 

 which is found to contain phosphoric acid and volatile alkali.' 

 The fat, too, has been said to differ from other animal mat- 

 ters in yielding, by distillation, a strong acid, but no volatile 

 alkali. There is also much variety and state of the combi- 

 nations of the saline and other matters, in different secreted 

 fluids. 



Animal oils and fats, like the gross oils of vegetables, are 

 not soluble in water, but may be united with water by the 

 intervention of gum or mucilage. 



Most of them may be changed into soap by fixed alkaline 

 salts, and may thus be rendered mixible with both spirit 

 and water. 



The odorous matter of some odoriferous animal substances, 

 as musk, civet, castor, is, as well as essential oil, soluble in 

 spirit of wine, and volatile in the heat of boiling water. 



It is said that an actual essential oil has been obtained from 

 castor in a very small quantity, but of an exceedingly strong, 

 diffusive smell. The blistering matter of cantharides, and 

 those parts of sundry animal substances in which their pecu- 

 liar taste resides, are dissolved by rectified spirit, and seem to 

 have some analogy with gummy resins. 



The gelatinous principle of animals, like the gum of vege- 

 tables, dissolves in water, but not in spirit or in oils j like 

 gums, also, it renders oils and fats mixible with water into a 



