LIME. 13 



plants that vegetate in it. The power that -lime has of 

 absorbing moisture will be better understood, when we 

 say, that one hundred weight will, in five or six days, 

 when fresh, absorb five pounds of water, and that it 

 will retain in the shape of powder, when slackened, or 

 loosened, as is commonly said, nearly one-fourth of its 

 weight.* 



That lime rehardens after being made soft, as in mor- 

 tar, is owing to the power which it has of acquiring 

 carbonic acid the fixed air of Dr. Black from the at- 

 mosphere ; when the stone is burned, it loses this prin- 

 ciple, but re-absorbs it, though slowly, yet in time, and 

 it thus becomes as hard as stone again : we unite it 

 with sand to promote the crystallization and hardening. 

 The utility of lime in various arts, agriculture, manu- 

 factories, and medicine, is very extensive, and in many 

 cases indispensable ; and the abundance of it spread 

 through the world seems designed as a particular pro- 

 vision of Providence for the various ends of creation. 

 Lime, and siliceous substances, compose a very large 

 portion of the dense matter of our earth ; the shells of 

 marine animals contain it abundantly ; our bones have 

 eighty parts in one hundred of it ; the egg-shells of 

 birds above nine parts in ten during incubation, it is 

 received by the embryo of the bird, indurating the 

 cartilages, and forming the bones. But the existence 

 and origin of limestone are pre-eminent amongst the 

 wonders of creation ; nor should we have been able, 

 rationally, to account for the -great diffusion of this sub- 

 stance throughout the globe, however we might have 

 conjectured the formation, without the Mosaical revela- 

 tion. It may startle, perhaps, the belief of some, who 

 have never considered the subject, to assert what is ap- 



* The weight of lime is very variable, differing in different places ; 

 but taking our lime at the average of eighty pounds to the bushel, 

 Borne idea may be conceived of the cooling nature of this substance. 

 Lime, to be used as manure, must be in a pulverized state ; and by 

 drawing on the land the quantity that we do, we convey to every 

 acre so dressed equivalent to two hundred and fifty gallons of water, 

 not to be evaporated, but retained in the soil as a refrigerant to the 

 fibres of vegetation. 



B 



