FATS. 245 



There are certain ferments which resolve the fats into glycerine 

 and the corresponding fatty acid, in the same manner as sugar is 

 resolved into alcohol and carbonic acid, or salicin into saligenin 

 and sugar, or amygdalin into sugar, hydrocyanic acid, and oil of 

 bitter almonds. Albuminous substances which have already under- 

 gone a certain degree of decomposition (putrefaction) act in this 

 manner as ferments to the fats. 



If we mix putrid fibrin, which forms an albuminous fluid, with 

 water, or putrid casein with fat, so as to form an emulsion, and 

 digest the mixture for some time at a temperature of 37> the cor- 

 responding fatty acids separate from the oxide of lipyl, which very 

 soon undergoes further alterations. In the fermentation of milk, 

 where sugar is present, it appears from my investigations* that the 

 fats are decomposed in precisely the same manner as if merely the 

 putrefying protein-compounds were acting as ferments, and as if no 

 sugar were present. Cl. Bernardf on digesting fats with pancreatic 

 fluid observed that they were decomposed into fatty acids and gly- 

 cerine, from which he concluded that during the act of digestion 

 the fats are constantly decomposed into glycerine and fatty acids 

 a conclusion, however, still admitting of considerable doubt. 



By dry distillation certain fats yield other fatty and inflammable 

 substances, and leave a little charcoal ; others are in part converted 

 into peculiar fatty acids. When very rapidly heated or thrown on 

 incandescent bodies, they carbonise and develope olefiant gas. 



The fats are decomposed by prolonged contact with chlorine, 

 bromine, and iodine ; while, on the other hand, they take up sul- 

 phur, selenium, and phosphorus, without undergoing any change ; 

 with the former, they only undergo decomposition on the appli- 

 cation of heat. 



By concentrated mineral acids they are for the most part con- 

 verted into fatty acids, and on the application of sulphuric acid, 

 they yield acid sulphate of glycerine. 



S tear ate of oxide of lipyl, stearin, occurs as a pure white sub- 

 stance ; it separates on cooling from its alcoholic solution in snow- 

 white, glistening scales ; under the microscope it appears chiefly in 

 the form of quadrangular tablets, which although almost square are, 

 according to Schmidt, J rhombs with angles = 90 5', but sometimes 

 in the form of short rhombic prisms (thick rhombic plates,) whose 

 surfaces, according to Schmidt, are inclined to one another at 



* Simon's Beitr. Bd. 1, S. 63-76. 



t Arch, ge'iie'r. de me'd. 4 Se'r. T. 19, p. 73, 



t Entwurf u. s. w. S. 84. 



