266 CHEMISTRY. 



is also called calomel. Mercuric chloride is commonly call- 

 ed corrosive sublimate ; it contains twice as much chlorine 

 as the first-named chloride, and is written HgCl 2 . 



Calomel is an insoluble and mild substance ; but corro- 

 sive sublimate, merely by having this additional quantity 

 of chlorine, is soluble, and acts as a corrosive poison, burn- 

 ing and eating wherever it goes. It is much used for the 

 destruction of vermin. It has sometimes been swallowed 

 by mistake. It produces most distressing symptoms, end- 

 ing very commonly in death. The accident happens usu- 

 ally in one or the other of two ways : either a bottle which 

 has had a solution of corrosive sublimate in it is carelessly 

 put aside, and is afterward used for some other purpose, 

 perhaps for bottling cider ; or the bottle containing the so- 

 lution is put among other bottles without being properly 

 labeled, and, if the solution is made with alcohol, some of 

 it may be swallowed on the supposition that it is some kind 

 of liquor. It is in this latter case that such intense suffer- 

 ing is produced, because the poison is so concentrated. 

 But little is swallowed, for the individual is affected at 

 once by an intense burning in the throat, extending down 

 into the stomach. Every one ought to know the effectual 

 antidote which they have to this poison, for the earlier it is 

 used the better, and every moment's delay adds to the dan- 

 ger of the case. Fortunately the antidote is generally at 

 hand. It is the whites of eggs, which should be swallowed 

 freely. The albumen in this substance acts chemically 

 upon the corrosive sublimate, producing a compound that 

 is not poisonous. If there be no eggs at hand, give milk, 

 or flour stirred up in water, for there is some albumen in 

 these. 



377. Amalgamation. You have already learned ( 278) 

 that mercury forms with some of the metals alloys called 

 amalgams. This fact is made use of in freeing certain 



