56 Ayr ('cultural Irnpkments and Froduce. 



obligations, has snatclied a few moments from his professional 

 pursuits to furnish mo with the following sketch of tlie general 

 progress of agricultural chemistry. 



This department of applied science is now attracting to itselJ 

 the attention of able chemists in all countries ; and the contribu- 

 tions to knowledge resulting from the various investigations have 

 during the last few years been very considerable. To attempt 

 anything like an account of these results in this place is obviously 

 out of the question, and we content ourselves Avith little more 

 than an enumeration of the principal and most interesting inves- 

 tigations. 



In tliis country Mr. Lawes has continued his experiments om 

 the laws concerned in the feeding and fattening of animals, 

 taking, for the objects of trial, pigs and sheep. The number of 

 animals experimented upon, the intelligence and care brought to 

 bear upon every detail of the experiments, and the very consider- 

 able expenditure Avhich has evidently accompanied them, place 

 these investigations far in advance of any of a similar kind thai 

 have been undertaken elsewhere. Although the results are of a 

 practical character, the experiments of Mr. Lawes must not be 

 classed with the very numerous trials on the feeding of animals 

 that are to be found dispersed through agricultural publications, 

 and which are merely practical, being undertaken without refer- 

 ence to general principles. The results of Mr. Lawes' inquiries 

 are too numerous to be stated here, but they seem to point out 

 that a just balance of the different constituents of food is of more 

 importance in the feeding and fattening of cattle than a predomi- 

 nance of any one ; that neither the albuminous nor the farinaceous 

 elements of food have an exclusive value for the purposes to 

 which they are applied ; and that the classes of vegetables which 

 are peculiar in containing a high proportion of nitrogenous 

 matter are not necessarily, from that circumstance, the most 

 adapted in practice to produce that part of the animal body 

 (muscle) which most resembles them in composition. According 

 to Mr. Lawes, therefore, the valuation of foods in relation to their 

 contents in nitrogen is attended with much fallacy. 



Amongst other papers. Dr. Voelcker, of Cirencester College, 

 has published an account of experiments made Avith a view oi 

 ascertaining the cause of the fertility produced by burnt clay 

 when used as manure. He has arrived at the opinion that the 

 effects are partly mechanical, but principally due to the libera- 

 tion of potash from silicates of that alkali existing in the soil, 

 but only slowly available until released by torrefaction. 



Mr. Way has published two further papers on the Important 

 subject of the absorption of manure by soils, in continuation oC 

 his first research on this subject, which Avas published in 1850.. 



