AGRICULTURAL CHEMISTRY. 85 



tis. The salts formed by nitric acid are easily soluble. 

 Hence they are uncommonly quick in their operation 

 on plants. The Chinese gardener understands that by 

 means of old plastering, which contains much nitrate 

 of lime, he can force the growth of vegetables almost 

 at pleasure, and cause an immense produce. In our 

 country, such old plastering is too often thrown away. 



51. Muriatic Acid (HCl) is 1 atom of Chlorine, 

 to 1 of Hydrogen. Thirty -seven lbs. of it would give 

 36 lbs. of chlorine and one of hydrogen. It was for- 

 merly called Spirits of Salt. Its more appropriate name 

 is Hydrochloric acid, because this name indicates the 

 materials of which it is composed. But it is more com- 

 monly known in England as Spirit of Salt, and in this 

 country as Muriatic acid. 



52. Water (HO) is composed of i atom of Hy- 

 drogen, to 1 of Oxygen. Could you decompose a pint 

 of water, it would give 1000 pints of Oxygen, and 

 2000 of Hydrogen. The Oxygen would weigh just 8 

 times as much as the Hydrogen, showing it to be just 

 16 times as heavy, by equal bulks. If now you should 

 mix the two together, they would condense into 2000 

 pints ; and if you then send an electric spark through 

 them, they will combine into Ipint of water. Conse- 

 quently you perceive, that water must be just 1000 

 times heavier than Oxygen, and just 2000 times 

 heavier than Hydrogen. Hydrogen is 16i tiipes lighter 

 than Oxygen and 14 times lighter than air, being, as 

 before stated, the lightest of all known substances. 



This is a well-known substance, and yet much is 



