1 72 Analysis of several Varieties of 



Each specimen of salt was reduced to a fine powder, and 

 was dried, in the temperature oi 180°. of Fahrenheit, during 

 the space of two hours. This was clone in order th 

 different ex peri men: s might be made on precisely equal 

 quantities of salt. 



I. To separata the earthy Muriates. 



(A.) On 1000 grains of the dried and pulverized salt, 

 (except in the case or' 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 toge- 

 ther for some time in a mortar, and then transferred into a 

 glass matrass, 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 

 jay oti the filter, with four 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 so- 

 lution might, however, still contain a minute portion of 

 muriate or soda. It was therefore again evaporated, redis- 

 solved in hot water, and mixed with a solution of carbonate 

 of soda. By boiling for some -minutes., the whole of the 

 earths were precipitated, and, after being well washed, were 

 re-dissolvcd in muriatic acid. This solution, being eva- 

 porated to dryness, gave the weight of the earthy muriates, 

 wh re h had bee hex trae ted b y al coh ol f . 



(B.a.) The dry mass thus obtained might consist either 

 of muriate of magnesia, of muriate of lime, or of both. 

 An aliquot part, therefore, was dissolved, separately, for 

 the purpose of assaying it by the usual tests. Sometimes, 

 as in the case of the earthy muriates procured from sea salt, 

 muriate of magnesia alone was indie/, .- d, and any further 

 process was rendered unnecessary. Muriate of lime was 



* In this and all similar cases, the heat was very cautiously regulated to- 

 wards the close of the piob 



•j* By the analysis of arrificia: mixtures of pure muriate of soda with the 

 earthy muriates in known quantities, I afterwards found- that the frill 

 amount of the earthy muriates was not ascertained in this w.iy of .proceeding. 

 The deficiency of the latter salts was ahout one sixth; but as the error must 

 necessarily have bee:* the samy in all, it does not affect the comparison of 

 different varieties of salt, as to their proportion of this ingredient. If the 

 numbers in the 5th c : . table (indicating: the total earthy mu- 



riates) be increased in the proportion of six to five, we shall then obtain the 

 *rue quantities in each variet 



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