818 CONTRIBUTIONS TO OUR KNOWLEDGE OF SOIL-FERTILITY, 



very dark brown substance. It is possible that the petroleum- 

 ether dissolves waxes and fats, while the darker bodies may be 

 resins. A mixture is to be expected from such a substance as 

 soil, but, as the bulk is soluble in petroleum-ether, and as the 

 substance is of a wax-like nature, I propose, for convenience' sake, 

 to name it " agricere." 



The agricere (0"39 grra.) was obtained from 500 gras. of garden- 

 soil by means of hot chloroform, and distilled in a small retort, 

 previous observation having shown that .some of the wax could 

 be volatilised. Several drops distilled over, varying in colour 

 from white to brown, but about one-thii d of the quantity remained 

 behind, condensing as it volatilised, while a portion charred The 

 wax or fat was separated from the carbon residue, and both 

 volatile and residual fatty matters were boiled with alcoholic 

 potash. After expulsion of the alcohol, ether extracted an 

 unsaponifiable portion; and the liquid, after treatment with 

 sulphuric acid, yielded brown fatty acids. The heating appeared 

 to destroy the substances of rather high melting point, as both 

 volatile and residual portions melted at 52°, and were identical. 

 The unsaponifiable matter melted at 43°, and the fatty acids at 

 53° to 54°. 



The portion of a hot alcoholic extract, insoluble in petroleum- 

 ether, melted at 95°, and yielded a non-sapotiifiable portion melting 

 at 64°, and fatty acids at 68°. The ethereal solution was lost. 



Petroleum-ether dissolved an agricere melting at 73°. This 

 gave an unsaponifiable portion, m. p. 57°, and fatty acids,m.p.69°-70°. 

 The former was again saponified, and yielded unsaponifiable 

 matter,m.p.54°-55°, and fatty acids,m.p.57°-58°. 



The agricere is evidently a complex substance, the components 

 of which are found to differ according to the solvent used. The 

 components appear to be of the nature of waxes or fats which 

 yield fatty acids upon saponification, and of parafiin-like bodies 

 which are not saponifiable. 



The observation that led to the discovery of agricere, also made 

 it evident that the solvent caused a redistribution of tliis sub- 



