HORTICULTURAL SOCIETY OF LONDON. 



333 



careful and often tedious experiments must be made before any 

 useful deductions can be obtained. 1 shall therefore not attempt 

 at present to produce any Keport on the experiments which have 

 already been made on this subject, but confine myself to a few 

 remarks on the way in which some of the inquiries are being 

 conducted. In order to trace out the apparent connection be- 

 tween the various vegetable productions, and the soil on which 

 the plants yielding them grow, collections have been made from 

 various parts of the kingdom of timber, fruits, seeds, 8cc., and 

 the soils on which they were raised ; these are being analysed, 

 and the results can hardly fail to be of great interest. The second 

 stage of these experiments consists in the endeavour to apply to 

 practice, the rules deduced from the experiments already made j 

 attempts are made to improve or alter the quahty of the produce, 

 by the application of those substances which were found to have 

 been absorbed from the soil by the plants which yielded the best 

 timber, or seeds. It is almost unnecessary to observe that in 

 these experiments attention must at the same time be paid to 

 many other circumstances, besides the mere chemical composi- 

 tion of the soil. The great influence of meteorological agency, is 

 not forgotten, and especial attention has been paid to the mecha- 

 nical texture of the soil. On this latter point an extensive series 

 of experiments has been made and the results obtained will be 

 shortly laid before the Committee. The influence which the state 

 of division and cohesion of the soil has on its fertility seems to 

 have been somewhat overlooked by writers on agricultural che- 

 mistry, whilst in fact there appears good reason to consider it even 

 more important than the chemical composition of the soil. 



In the course of the experiments which have been made in 

 connexion with this investigation, many facts have been ascer- 

 tained not immediately connected with the main object of in- 

 quiry. Some of these which appear new, are perhaps worthy of 

 record. At present 1 shall say nothing of those experiments, or 

 trains of investigation which are intended to form the subjects of 

 future reports, but confine my remarks to a few points which, 

 though of less importance, yet appear deserving attention. 



One of the substances of the greatest interest in vegetable che- 

 mistry is SULPHUR ; it occurs in the soil, the air^ in many vege- 

 table substances, and in several of the best manures. What in- 

 fluence has it on growing plants ? There are two compounds of 

 Sulphur with which we have to deal in this consideration, namely 

 that which it forms with oxygen, the sulphuric acid, and that which 

 it forms with hydrogen, viz. sulphuretted hydrogen or hydro- 



