no Dr. Henry’s Analysis of several Varieties 
weight of the earthy muriates, which had been extracted by 
alcohol.* 
( 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, mu- 
riate of magnesia alone was indicated, and any further process 
was rendered unnecessary. Muriate of lime was in no instance 
found uncombined ; but in the majority of cases (as in the 
earthy muriates obtained from Cheshire salt) was mixed with 
muriate of magnesia. 
(B.b. ) To the solution of two earthy muriates was added 
fully saturated carbonate of ammonia, which has the property 
of throwing down lime in combination with carbonic acid, blit 
has no effect on the muriate of magnesia at ordinary tempe- 
ratures. The solution of the latter salt, alongwith that of the 
excess of carbonate of ammonia, was therefore separated by 
filtration ; and to the filtred liquor a solution of phosphate of 
soda was added, according to the formula of Dr. Wol- 
laston. - f 
■* By the analysis of artificial mixtures of pure muriate of soda with the earthy mu- 
riates in known quantities, I afterwards found that the full amount of the earthy 
muriates was not ascertained in this way of proceeding. The deficiency of the latter 
salts was about one sixth ; but as the error must necessarily have been the same in 
all, it does not affect the comparison of different varieties o f salt, as to their propor- 
tion of this ingredient. If the numbers in the 5th column of the table (indicating 
the total earthy muriates) be increased in the proportion of six to five, we shall then 
obtain the true quantities in each variety of salt. 
f See Dr. Marcet’s analysis of the Brighton Chalybeate, published in the last 
edition of Saunders on Mineral Waters. 
