100 
of British and Foreign Salt. 
Each specimen of salt was reduced to a fine powder, and 
was dried, in the temperature of i8o° of Fahrenheit, during 
the space of two hours. '1 his was done in order that the 
different experiments might be made on precisely equal quan- 
tities of salt. 
I. To separate the earthy Muriates. 
( A) On 1000 grains of the dried and pulverized salt, (ex- 
cept in the case of the foreign salts . when only 500 grains 
were used,) four ounce measures of alcohol were poured, of a 
specific gravity, varying from 815 to 820, and at nearly a 
boiling temperature. To insure the access of the fluid to 
every part of the salt, they were ground together for some 
time in a mortar, and then transferred into a glass mattras, 
where they were digested for some hours, and frequently 
agitated. The alcohol was next separated by filtration, and 
the undissolved part was washed, as it lay on the filtre, with 
4 ounce measures of fresh alcohol. 
(B ) The united washings were evaporated to dryness,* 
and to the dry mass a small portion of fresh alcohol was 
added, to separate the earthy muriates from a little common 
salt, which had been dissolved along with them. This solu- 
tion might, however, still contain a minute portion of muriate 
of soda. It was therefore again evaporated, redissolved in hot 
water, and mixed with a solution of carbonate of soda. By boil- 
ing ft r some minutes, the whole of the earths were precipitated, 
and after being well washed, were re-dissolved in muriatic 
acid. This solution, being evaporated to dryness, gave the 
* In this and all similar cases, the heat was very cautiously regulated towards the 
close of the process. 
