206 



^ 



MANURES. 



Sect. X. 4. 8. 



neral waters. And this I fuppofe to be the great ufe of lime in agri 

 culture. 



+ 



For the purpofe of afcertaining the probability of this mode of fo 



lution of carbon I 



\ 



made the followinsf experiment 



to 



About two 



of lime in powder were mixed with about as much ch 



in powder, put into a crucible, and 



red with an inch or two of 



filiceous fand. The crucible was kept red hot for an hour or Ion 



^^ 



and then fufFered 

 lime and charcoa 



On the next day water was poured on th 



which then flood a day or two 



and 



quired 



open cup 



fcum 



filrface. And though it had 



not much tafte, except of the caufticity of the lime, yet on dropping 

 one drop of marine acid into a tea-fpoonful of the clear folution a 



* 



flrong fm ell like that of hepar fulphuris was perceived, or like that 



of Harrogate water ; which evinced, that the carbon was thus ren- 

 dered foluble in water. 



Perhaps the fulphureous fmell of Harrogate and Kedleflon waters. 



and other fimilar fp 



may be owin 



th 



of the alkali 



of decompofing marine fait with the carbon of the earth, they run 

 through ? and this kind of water might thus poflibly be ufed as a 

 profitable manure 



8. Another mode by which vegetable roots acquire carbon, I fuf- 

 pe(St to be by their difuniting carbonic acid from limeftone in its fluid 



? 



not its 



G 



(Teous ftate ; which the limeftone again attracts from th 



atmofphere and confolidat 



from other matters included 



th 



foil 



Firft, becaufe lime is believed by fome agricultors, who much 



employ 



do more ferv 



the fecond year th 



the firft 



that is in its mild ftate, when it abounds with carbonic acid, than in 

 its cauftic ftate, when it is deprived of it. 



Secondly, that the ufe of burning lime feems hence to be fimply 

 to reduce it to an impalpable powder, almoft approaching to fluidity; 



litate the application of the innumerable extremities 



which muft facilitate 



of vegetable fibres to this uncalculablc increafe of its furface 



which 

 may 



