320 GYPSUM. 



and in connection with crops that elsewhere derive the highest amovinl 

 of advantage from its use. This anomaly has been explained by 

 assuming, without proving experimentally, however, that the fact ia 

 so, that the soil in these districts naturally contains a sufficient dose 

 of gypsum. It has also been said that gypsum produces no effect on 

 low-lying and damp soils. 



The quantity of gypsum employed in different places, varies great- 

 ly : from li to 16 cwts. per acre have been recommended. The 

 quality of the article employed has a great influence on this question, 

 to say nothing of the price, which in many places is high. 



The opinions of practical men, with regard to the advantages and 

 propriety of applying gypsum, although they agreed in certain de- 

 terminate circumstances, were still far from being unanimous upon 

 every point. A particular inquiry into the subject was therefore 

 held worthy of its attention by the French government, and a com- 

 prehensive report on all the information collected, was made by M. 

 Bosc to the Royal Central Agricultural Society of France. This 

 report shows in a striking manner the advantage that may be deriv- 

 ed from the lights of practical men ; in a single line or sentence wo 

 frequently find a summary of twenty or thirty years of experience. 

 It is, however, indispensable to go to these gentlemen for their in- 

 formation ; the agriculturists who devote themselves to cultivation, 

 it is notorious, write very little, and those who spend very little 

 time in this way, on the contrary, write a great deal. It may be 

 that the reason for the silence of the one, is that also for the elo- 

 quence of the other. 



The following series of questions and answers I believe to em- 

 brace most of the points connected with the employment of gypsum, 

 that are of interest. 



1st. Does plaster act favorably on artificial meadows? Of 43 

 opinions given, 40 are in the affirmative ; 3 in the negative. 



2d. Does it act favorably on artificial meadows, the soil of which 

 is very damp? Unanimously, no. Ten opinions given. 



3d. Will it supply the place of organic manure, or of vegetable 

 mould 1 i. e. will a barren soil be converted into a fertile one by the 

 use of plaster ? No, unanimously. Seven opinions given. 



4th. Does gypsing sensibly increase the crops of the cereals'? Of 

 32 opinions, 30 negative, 2 affirmative. 



The information thus obtained, valuable as it is, cannot yet be held 

 to embrace every thing that seems desirable. Happily, all that was 

 wanting has been supplied by the individual inquiries of Mr. Smith 

 in England, and of M. de ViMle in France. 



The soil upon which Mr. Smith made his experiments was light, 

 with a substrate of chalk ; the vegetable earth was a yard in depth 

 at the top of the field, and lessened gradually, in such a way that at 

 bottom it was but three inches thick. Every precaution was taken 

 that the respective breadths contrasted should be as nearly as possi- 

 ble in the same circumstances. The following table shows the 

 teeulta : 



