Chemical Examination of American Minerals. 1 1 



2. Those which, in order to dissolve in muriatic acid, 

 must be heated to redness, with a mixture of thrice their 

 weight of dry carbonate of soda. 



3. Those which require to be heated with caustic potash, 

 in order to render them soluble in muriatic acid. 



1. The greater number of the minerals formerly con- 

 founded under the general name of zeolites, are readily solu- 

 ble (if in sufficiently fine powder) in muriatic acid. These 

 consist of various hydrous silicates, united together in very 

 different proportions. Silicates of alumina, of lime, of iron, 

 of potash, or of soda, are the most common of these bodies. 



a. I usually operate on 25grs. or 30 grs. when the mineral 

 contains much water. The mineral, previously reduced to a 

 fine powder, is put into a flask, and digested on the sand bath 

 with diluted muriatic acid till a solution is obtained. Great 

 care must be taken to prevent any of the silica contained in 

 the mineral from adhering to the inside of the flask. This is 

 best done by agitation, which should be almost constant. 

 And as soon as the mineral is dissolved, the whole contents of 

 the flask should be poured into an open evaporating dish, 

 before the silica begins to gelatinize. Should the silica from 

 inadvertence be allowed to adhere to the inside of the flask, 

 it cannot be washed out by water or acids. A little potash- 

 ley, assisted by a gentle heat, will readily dissolve it. But 

 great care must be taken not to act upon the glass flask. 



The acid solution is evaporated to dryness, and water aci- 

 dulated with muriatic acid, is digested on the dry residue, 

 till every thing is taken up except the silica ; the whole is then 

 carefully washed into a filter. 



The filtering paper which I use, is unsized printing paper, 

 procured from the papermaker. Our paper, from the great 

 diversity of materials employed in its manufacture, and from 

 the process of bleaching the rags by means of chloride of 



