240 Dr. Marcet on an Aluminous Chalybeate Spring 



soda ,: but the circumference was strewed with numerous and per- 

 fectly regular crystals of muriat of soda.* 



3. This saline mass being dissolved in water the solution had 

 the following properties : 



a. It was neither acid nor alkaline, 



b. Its most obvious taste was that of muriat of soda. 



c. It formed copious precipitates with nitrat of barytes, nitrat of 

 silver, and nitrat of lime. 



d. Oxymuriat of platina, oxalat of ammonia, and prussiat of 

 potash, produced no precipitate whatever. 



Therefore the only salts contained in this solution were sulphat 

 of soda, and muriat of soda. 



4. As to the proportions of those two salts, it would have been 

 easy to ascertain them by precipitating their acids. But it occurred 

 to me that the sulphat of ammonia formed in the solution by the 

 ammoniacal salts which had been introduced for the precipitation of 

 the earths, had probably reacted upon the muriat of soda when 



* This result shews the compatibility of muriat of soda with sulphat of iron, the latter 

 being in excess, m hich has been questioned by some chemists. Being desirous of ol)tain- 

 ing a confirmation of this by a direct experiment, I mixed together solutions of two parts 

 of sulphat cf iron and one part of muriat of soda. The mixture became yellowish, and 

 on applying heat reddish flakes subsided. On separating these by filtration, and repeat- 

 ing this process two or three times, I nevertheless obtained by evaporation distinct 

 crystals of muriat of soda, partly cubic, partly octohedral, deposited in the centre of a 

 saline yellowish mass, without any appearance of efflorescence or of any thing resem- 

 bling sulphat of soda. Therefore muriat of soda is compatible with sulphat of iron, 

 although these two salts evidently exert some degree of action on each other, as appeared 

 from the change of colour and the formation of reddish flakes, which I suppose to be 

 sub-sulphat of iron. I may take this opportunity of mentioning that by an analogous 

 experiment on sulphat of iron and muriat of alaminc, and by the assistance of alcohol, I 

 Mtisfied myself that those two sails could not exist together. 



