IMPORTANCE OF SUCH EXPERIMENTS. 363 



tained from that to which no application was made, are also highly de- 

 serving of notice. 



Mr. Burnet has transmitted to me samples of the flour from these 

 several growths of wheat, with the view of determining the relative 

 proportions of gluten they contain. The result of this examination, 

 which cannot fail to be interesting, will be given in a succeeding Lec- 

 ture — before which, however, I hope the whole of Mr. Burnet's experi- 

 ments will be laid before the public. 



It will be observed that Mr. Burnet has exercised a sound discretion 

 in making and trying mixtures not hitherto specifically recommended. 

 It is by the result of such varied experimental trials, made by intelli- 

 gent practical men, on different soils and crops, and with mixtures of 

 which the constitution is exactly known, that we shall be able hereafter to 

 correct our theoretical principles — as well as to simplify and render 

 more sure our general practice. 



[Since writing the above, lam informed that the silicate ofpotashj re- 

 ferred to at p. 349, is manufactured by Messrs. Dymond, of London, and 

 may be obtained from the London dealers at 56s. a cwt. I expect also, 

 that a silicate of soda will soon be brought into the market by the Messrs. 

 Cooksons, of the Jarrow Alkali Works, at a much lower price. The 

 probable efficacy of these substances, as manures, has, no doubt, been 

 extolled too highly by some — their real efficacy, however, is well de- 

 serving of investigation. I insert in the Appendix No. VII, therefore, 

 some suggestions for experiments with these substances, in the hope that 

 during the spring of 1843, some experiments on the subject may be 

 made. 



