234 Dr. y\.K'9.z^i on an Aluminous Chalyheate Spring 



3. It was therefore necessary to separate the Iron previous to 

 the precipitation of the lime. This was done in one instance by 

 prussiat of potash, and in another by succlnat of ammonia. I 

 shall not trouble the society with the detail of these operations. It 

 will be sufficient to state, that the two most unexceptionable experi- 

 ments indicated the one 8 grains, and the other 8,3 grains of 

 oxalat of lime, dried at 160°, for each pint of the water, making an 

 average of 8,15 grains of oxalat of lime, or 10,17 grains of sulphat of 

 lime dried at 160° j or 7,94 grains of the same salt dried at a red 

 heat*. 



§ XI. Inferences obtained from the application of Alcohol. 



1. Having ascertained (§ III. k), that a small quantity of muriatic 

 acid was present in the water, it became desirable, before proceeding 

 any farther, to discover, by the agency of alcohol, which has the 

 well known property of dissolving the earthy muriats, with what 

 bases this acid was combined. With this view, 20 grains of 

 residue were digested In successive quantities of alcohol of great 

 purity, and the solution filtered. The residue, by this operation, 

 acquired a lighter colour and a more pulverulent appearance. Part 



4. If a solution of potash be added to the washed precipitate, previous to the appli- 

 cation of heat, a strong smell of ammonia arises, and the oxyd passes to a dark greyish 

 colour, showing that the precipitate is a triple salt of oxalic acid, iron, and ammonia. 



* I avail myself, in forming these various estimates, of the proportions given by Dr. 

 Henry, in his valuable' Analysis of s&vcral varieties of Sea Salt' (published in the Philo- 

 sophical Transactions for 1810, page 114), where he states that 100 grains of ignited 

 sulphat of lime (which he finds to be equal to 128 grs. dried at 160°), give 102,5 grs. of 

 oxalat of lime dried at 160°; so that 100 grs of oxalat of lime dried at 160°, corres- 

 pond to 124 grs. of sulphat of lime dried at the same temperature. 



1 



