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had deposited a large portion of salt, out of which 

 sprung at a small distance from each other, about forty 

 branches, which exactly resemble fern, putting out 

 many leaves on each side, from one stem. They were 

 of different sizes, but the figures of all were pre- 

 cisely the same. And these artificial vegetables, tak- 

 ing care not to shake them, I preserved for many 

 weeks." 



And yet the following account is stranger still. 

 " I mixed equal parts of sal ammoniac and pot-ashes 

 which were put into a tall glass body, with plenty 

 of volatile salt sublimed. I expected no unusual ap- 

 pearance from this, having often repeated the opera- 

 tion. Being called out just as the salt began to ap. 

 pear, how was I amazed at my return, to see in the 

 glass-head a forest in perspective, so delineated, as 

 scarce to be equalled by the greatest masters. They 

 were a representation of firs, pines, and another sort 

 of tree which I had never seen. But of this delightful 

 spectacle, 1 was soon deprived by the sublimation of 

 more salts. 



" The next day I related this to Sir Robert Murray. 

 He told me, one Davison, an experienced chymist, 

 at Paris, had frequently shewed him in a glass a great 

 company of firs and pines, full as lively as any can be 

 painted. But in a little time they disappeared. He 

 produced them again at pleasure. But herein his ope. 

 ration differed from mine: the substance out of 

 which he raised those shapes was of a more fixed na- 

 ture ; that which afforded mine, was volatile to the 

 highest degree. Again, He could constantly and re. 

 gularly produce those beautiful representations: 

 whereas mine unexpectedly appeared ; nor have I any 

 hope of seeing them again." 



Sal ammoniac is made of the soot arising from the 

 dung of four-footed animals, as sheep, oxen, arid ca- 

 mels, so long as they feed only on green vegetables. 

 This dung is collected in the fo'ur first months of the 

 year, when all these feed on fresh spring grass. This 



