2S6 Oft Gypsum. 



ragement, — Sir H. Davy's Elements of Agricul- 

 tural Chemistry ; — I cannot refrain from adding 

 to that note ; although I may not be justified by the 

 importance of my observations. 



When the paper of Mons. Berard{s^t Vol. 2d, 206) 

 on the ^^ Efficacy o/" Sulphur, as a Manure,'^'' v^2i^ 

 shewn to Mr. Davy^ he observed to a friend of mine, 

 who related to me the circumstance, that he expected 

 he should soon prove, that Mr. Berard was mistaken 

 in his ideas of the operative causes, both of Sulphur 

 and Plaster, I confess my curiosity was strongly ex- 

 cited, when I saw Sir // Davy's work announced, 

 I have the highest opinion of Mr. D's talents as a che- 

 mist, and able investigator, into all subjects he under-, 

 takes. But \ was completely disappointed, in all my 

 expectations on the subject of Gypsum ; whatever may 

 be their weight with others. It most assuredly appears, 

 to nie, the least satisfactory of any part of this estimable 

 and popular performance ; and causes me to despair of 

 any profitable assistance, in this desideratum, from the 

 most eminent chemists. Little or nothing (so far as I am 

 capable of judging) can be collected from it, decisively 

 settling any, useful question. To us, who are so well, 

 and have been so long, acquainted with results, that 

 we need no further experimental speculations ; the 

 facts or conjectures, are really unimportant. What I 

 expected to see luminously treated (after what I had 

 heard) is either not touched on, or by no means (as I 

 conceive) proved. He finds Gypsum (its component 

 parts not mentioned) in all animal manure, grasses, 

 and in the earth of cultivated, as well as soddy, fields. 

 When the plaster strewed does not operate, it is be^ 



