112 TOWN GEOLOGY. [v. 



prodigy ; and the settlers coming back to look for the 

 dropped sack, saw a sight which told the whole tale. 

 For the poor creatures, in their terror, had thrown 

 away their pans and calabashes, each filled with that 

 which it was likely to contain, seeing that the sack 

 itself had contained, not flour, but quick-lime. In 

 memory of which comi-tragedy, that creek is called to 

 this day, " Flour-bag Creek.-" 



Now I take for granted that you are all more 

 learned than these black fellows, and know quick-lime 

 from flour. But still you are not bound to know what 

 quick-lime is. Let me explain it to you. 



Lime, properly speaking, is a metal, which goes 

 among chemists by the name of calcium. But it is 

 formed, as you all know, in the earth, not as a metal, 

 but as a stone, as chalk or limestone, which is a 

 carbonate of lime ; that is, calcium combined with 

 oxygen and carbonic-acid gases. 



In that state it will make, if it is crystalline and 

 hard, excellent building stone. The finest white 

 marble, like that of Carrara in Italy, of which the most 

 delicate statues are carved, is carbonate of lime altered 

 and hardened by volcanic heat. But to make mortar 

 of it, it must be softened and then brought into a state 

 in which it can be hardened again ; and ages since, 

 some man or other, who deserves to rank as one of the 

 great inventors, one of the great benefactors of his 

 race, discovered the art of making lime soft and hard 

 again ; in fact of making mortar. The discovery was 

 probably very ancient ; and made, probably like most 

 of the old discoveries, in the East, spreading Westward 

 gradually. The earlier Greek buildings are Cyclopean, 

 that is, of stone fitted together without mortar. The 



