made to his labours in Agricultural Chemistry, he would 

 state here some of the results at which he had arrived. 



He had, in 1839 and 40, detected the presence of crenic and 

 apocrenic acids in soils and peats ; and, since then, other substances 

 of an important character. In the Report on the Geology and 

 Agriculture of Rhode Island, he announced the discovery of an 

 undescribed substance, which he had, during the past winter, ex- 

 amined more thoroughly. It was obtained from a solution of 

 organic matters in the soil, the crenic and apocrenic acids having 

 been previously separated; the copper of the solution was precipi- 

 tated by sulph. hydrogen, and from the remainder an extractive- 

 like mass was obtained, soluble in distilled water, which yielded an 

 ash grey precipitate on addition of sub-carbonate of lead, which 

 consisted of 15 parts of an oxide of lead, and 6 parts of a new 

 substance. While examining this substance, he received the in- 

 formation that the same substance had been discovered by Berze- 

 lius, and denominated by him Humic acid, the same tests having 

 been used as in the present analysis. 



The following substances were now known to exist in all fertile 

 soils ; apocrenic acid, crenic acid, humic acid, Humin, extract 

 of Humus, and carbonate of Humus. To these Dr. J. thought 

 Glairin might be added, as he had discovered it in three fertile 

 soils. Thus we have the bodies formerly known as ulmic acid, 

 Ulmin, Geine, and Apotheme resolved into seven distinct sub- 

 stances. 



Dr. J. stated that he had noticed the fact that glasses in which 

 Hyacinth bulbs had been grown, were corroded. He had also 

 noticed the same effects on bottle glass, which had lain in garden 

 mould. He supposed that the plants had the power of decompos- 

 ing glass as well as the felspar of granite, and of appropriating to 

 their use the potash contained in it, and that this was the source of 

 the potash contained in the ashes of plants. 



Dr. J. thinks that Liebig's work contains many interesting 

 observations, and some important errors. With regard to the ex- 

 istence of ammonia in the rain, he thought it was to be regretted 

 that Liebig had not experimented on water taken from the interior 

 of a mountainous country, where it would have been less liable to 

 derive this substance from the combustion of coal and other sub- 

 stances. Carbonate of ammonia has long been distinguished foi 

 2 



