FARMER'S ASSISTANT. 221 



After the burning, it is easily reduced to powder ; and as 

 a proof of its great value, as a manure, he observes it is 

 carried forty and fifty miles into the country, on the backs 

 of Asses. 



Mr. Livingston is of opinion that the sulphuric acid in 

 this, as well as in gypsum, is the fertilizing principle; that 

 in this slow combustion this acid is absorbed in the burnt 

 earth, while the inflammable matter is dissipated; and t> at 

 the union of the alkali and the acid forms a salt not unlike, 

 in its chemical relation, to gypsum, or perhaps one that is 

 more soluble, more impregnated with the acid. 



Refering also to a circumstance mentioned by Duhamcl^ 

 where this acid being scattered over weeds, with the view 

 of destroying them, only made them grow with additional 

 vigor, he observes, that probably if it were diluted, and 

 applied to the soil, or mixed with woodashes, and applied 

 in that way, it might answer the purpose of gypsum. And 

 in order to find an acid that would be cheaper and better, 

 as being already composed of a constituent part ot vegeta- 

 bles, he observes that the pyro-ligneous acid may be obtain- 

 ed, at a trifling expense, by converting wood into charcoal, 

 and condensing the vapor; as the charcoal would of itself 

 repay the expense of the operation, particularly where wood 

 is cheap. 



Mr. Livingston further observes, that he has seen pyrites 

 on his own estate ; and advises that experiments be made 

 of this earth. It is to be laid in beds about four feet thick, 

 and while burning should be stired with a rake. When 

 cooled, pound it fine and sift it. If the earth should prove 

 tbo inflammable, he advises to give it a mixture of lime, 

 which, by the process of burning, would be converted into 

 gypsum ; or wood-ashes would be found useful. If the 

 pyrites be in lumps, it must be reduced to a coarse gravel, 

 before burning. 



A due attention to, the recommendation of Mr. Living* 

 ston on this subject might be productive of very beneficial 

 results, as no doubt many parts of the interior of this Coun* 

 try may be found, abounding in pyrites which are destitute 

 of gypsum. 



Mr. Chapman, of Pennsylvania, tried sulphuret of barytes* 

 calcined, as a manure, and found that it even exceeded 

 gypsum in its effects, not only on dry gravelly lands, but 

 also on clays. It drove insects from his garden. He con- 

 siders it the most powerful manure ever yet discovered. 

 Care must be taken, however, not to strew it on the grow- 

 ing plants, lest it kill them. 



In preparing some, for the purpose of making an experi- 

 ment, he took twenty-four pounds of this earth, mixed it 

 wU> ihree pounds of powdered charcoal, and put the whole 



