Thus in cows' butter, tributyrin, C 3 H 5 (O C 4 H 7 0) 3, and the analogous glycerides of other readily volatile acids closely resembling butyric acid, are present in small quantity; the production of these acids on saponification and distillation with dilute sulphuric acid is utilized as a test of a purity of butter as sold.
Normal butyric acid or fermentation butyric acid is found in butter, as an hexyl ester in the oil of Heracleum giganteum and as an octyl ester in parsnip (Pastinaca sativa); it has also been noticed in the fluids of the flesh and in perspiration.
Bacillus amylobacter usually accompanies the lactic acid organism, and decomposes lactic and other higher acids with formation of butyric acid.
It may be obtained in small quantity by passing ethylene or acetylene into boiling sulphur; by passing ethyl sulphide through a red-hot tube; by heating crotonic acid, butyric acid or erythrite with phosphorus pentasulphide; by heating succinic anhydride with phosphorus pentasulphide or sodium succinate with phosphorus trisulphide (J.
The cellulose membranes showed traces of subjection to butyric fermentation, such as is produced at the present day by Bacillus Amylobacter; he also claimed to have detected the organism itself.
Fitz (Ber., 1878, 11, p. 52) found that the butyric fermentation of starch is aided by the direct addition of Bacillus subtilis.
In addition to the fatty acids mentioned already there occur also, although in much smaller quantities, other fatty acids combined with glycerin, as natural glycerides, such as the glyceride of butyric acid in butterfat, of caproic, caprylic and capric acids in butter-fat and in coco-nut oil, lauric acid in coco-nut and palm-nut oils, and myristic acid in mace butter.
Glucose also undergoes fermentation into lactic acid in the presence of the lactic acid bacillus, and into butyric acid if the action of the preceding ferment be continued, or by other bacilli.
Two acids are known corresponding to this formula, normal butyric acid, CH 3 CH 2 CH 2.
Bacillus chauvaei ferments cane-sugar solutions in such a way that normal butyric acid, inactive lactic acid, carbon dioxide, and FIG.