ON THE COMPOSITION OF SOILS, &C. 197 



" posed entirely of hydrogene, oxygen, and car- 

 *' bon. Mr. Cruikshank made many experi- 

 ** ments on fermentation, and invariably found 

 " that whenever he added a fourth substance to 

 " the three which compose saccharine matter, no 

 " fermentation took place ; he tried limej and at 

 " another time a small quantity of potash, and 

 " the addition of eiXhQV prevented fermentation.^^ 



Sir Humphry Davy also says, *• Quick lime 

 " in its pure state, whether in powder or dis- 

 ** solved in water, is injurious to plants.*' 



I have found slacked lime, when sown or 

 spread over plants of all kinds and stages of 

 growth, to destroy slugs, effectually perform this, 

 and without in the least injuring the plants. 



As it must appear from these observations, 

 that I cannot practically and beneficially, further 

 apply the inferences of Sir Humphry Davy, 

 regarding the uses of lime in agriculture ; I shall 

 not obtrude any further remarks on his ideas 

 on the subject ; but shall give an extract from 

 the Encyclopaedia Britannica, which appears to 

 me, to be more clearly, if not correctly, explan- 

 atory of the uses and effects of lime in agri- 

 culture : but even this author, seems either not 

 to have understood the principles of the action 

 of lime, or to have erroneously described them. 

 He speaks of lime as a septic^ and of its assisting 



o 3 



