142 On the Application 



stituents of his land, so far as to determine its proper place in our 

 system of arrangement. 



Let me, however, remind you that such a rude analysis as I 

 recommend tells you nothing respecting the presence or absence 

 of many ingredients, which exist indeed in minute quantities 

 in the soil, but which nevertheless occasion the most decided 

 differences in its equalities as affecting vegetation. Such are the 

 alkalies and the phosphoric acid, both of which necessarily escape 

 detection whenever we examine such small quantities of the soil 

 as usually are submitted to analysis. It is therefore no reflec- 

 tion upon Sir H. Davy, in the last age, or on any chemist of 

 the present, if, under such circumstances, he is silent as to the 

 presence of these ingredients in the samples which he had under- 

 taken to analyse.* If, therefore, information be sought on these 

 points, larger portions of the soil must be sent, and a greater 

 amount of chemical skill v^ill be called into requisition ; but 

 where the object is merely to determine the sort of soil which 

 exists on a given property, then a small quantity only need be 

 examined, and a degree of science, such as would be easily 

 attainable by most farmers, will suffice. 



Furnished, then, with this species of universal language, the 

 agriculturist would be enabled to speak intelligibly, whenever 

 he attempted to convey to others the results of his own experi- 

 ments on the culture of land of a particular quality : he would 

 then stand in the position occupied by a physician of a remote 



* Thus Sir C. Lemon last autumn expressed to me his surprise that a 

 sample of the soil taken from the Serpentine of the Lizard was pronounced 

 by Mr. R. Phillips, to whom it had been sent for examination, to be totally 

 destitute of magnesia. I told him that I could myself state that no quan- 

 tity of that earth considerable enough to be detected in a sample consisting 

 of only a few hundred grains was present in it, having some time back 

 executed a rough analysis of this soil. It would have been rash, however, 

 to have concluded from this that magnesia was e7itirely absent, for ]\Ir. E. 

 Solby has since informed me, that by operating on a much larger amount 

 he has succeeded, not only in detecting ihe existence of the earth in ques- 

 tion, but even of estimating the proportion it bears to the other ingredients. 

 It has been remarked in the text, that phosphate of lime is another con- 

 stituent of soils often overlooked, owing to the small quantity usually 

 submitted to analysis. I may add, that several years ago I detected its 

 presence in a great many specimens of secondary limestones in which 

 Dr. Buckland had suspected the existence of coprolitic matter (one no 

 doubt, but by no means the only source, from which it is derived). Within 

 the last month I have been favoured by a letter from Mr. Schweitzer, the 

 intelligent Director of the German Spa at Brighton, in which he states that 

 he has discovered it in the proportion of one-thousandth part in the chalk of 

 Brighton, and I have since found the phosphate in a somewhat larger 

 quantity in the same formation, from the neighbourhood of Sudbury in 

 Suffolk. 



