156 



LESSONS IN CHEMISTRY. 



243. The following analyses will show you the composition 

 of several varieties of limestone, employed for agricultural 

 pui-poses in Ireland: — 



The above analyses of limestone rocks from various parts 

 of Ireland, will show you that they differ considerably in 

 their composition, and that when burned, they will convey 

 different quantities of lime to the soil. It is only lately that 

 attention has been directed to the amount of phosphate of 



paper, dried before the fire and weighed, will show the amount of earthy 

 impurities which the specimen of limestone contained. 



2. Take 100 grains of quicklime, pour water upon it as long as it 

 drinks it up ; observe the heat given out ; collect and weigh the powder 

 which it forms, and note the increase in weight produced. Drop some 

 of the powder into some diluted muriatic acid ; if the lime has been care- 

 fully burned, there should be no escape of gas. 



3. Introduce the remainder of the powder, with two or three glassfuls 

 of water, into a bottle ; cork the bottle, and shake the mixture ; allow 

 the undissolved part to settle down, and pour off the clear liquid, which 

 is lime-water^ and preserve it for experiment in a well corked vial. 

 Test the lime-water, and you will find it alkaline (12). Blow air into 

 it through a glass tube or straw, and it wall become muddy from the 

 formation of carbonate of lime, carbonic acid being contained in the air 

 from the limgs (26). 



