358 Contributions to Chemistry, etc. 
ten and tin. After thorough washing, it may be again fused 
with fluohydrate of potassium, and the double fluorid obtained 
mic and sulphuric acids may be precipitated together by acetate 
of lead. The precipitate after washing is to be boiled with 
eaustic alkalies, or with sulphur and carbonate of soda. 4 
From what has been said it will appear that fluohydrate 
possesses peculiar advantages in resolving those mim 
or gutta-percha. 
Cambridge, Mass., Jan. 18th, 1864. 
