166 On Gypsuin. 



decomposes the plaister ; and any undue admixture of 

 other acids or the gasses, though no salt air may exist, 

 may destroy its agricultural uses. It is so with the soil; 

 which, to be productive, must have a due proportion of 

 the parts administering to its fertility. Lands become 

 lime-sick, as it is called, after much of that manure has 

 been applied, for a great length of time. They recover, 

 so as to admit of new applications of it, after intermis- 

 sion and proper culture, with vegetable or animal ma- 

 nures, ploughed in. 



It is not strange, that, on the first appeai'ance of the 

 plaister, with bad properties ascribed to it, people 

 should have been incredulous. The prejudices and 

 want of faith should have ceased, when experiment had 

 verified facts, in proof of its qualities. But both incre- 

 dulity and prejudice continued, for a great length of 

 time. — Circumstances not uncommon, being too often 

 the attendants on thfe first introduction of all improve-* 

 ments ; however important and salutary. It was called 

 € objuring powder, magical dmt, &c. &c. by those who 

 amused themselves, with the supposed folly of the ad- 

 vocates for its efficacy and usefulness. 



Among its uses, I have lately been informed of one, 

 I had not before discovered. It has been given to horses 

 for the cure of the heaves; which is a cough and asthma, 

 the precursors of broken wind. Ha\'ing an horse 

 afflicted with this complaint, I followed, without preju- 

 dice for, or against them, the directions of my inform, 

 ant. A small handful of ground plaister is to be given 

 in the feed, four or fi^ e successive mornings ; when it 

 will operate as a strong purgative. The dose is to be re=. 



