in the Isle of Wight, ^41 



urged by heat, so as to decompose it partially, and form the sulphat 

 of soda obtained by the process just described ; so that muriat of 

 soda might perhaps in fact be the only alkaline salt contained in the 

 water. 



5. In order to ascertain this, another portion of the chalybeate 

 having been treated in the way just described with succinat of am- 

 monia, the residue was gradually desiccated, and then heated to red- 

 ness in a platina crucible, which was at first kept closed, in order to 

 retard the escape of the sulphat of ammonia, and thus promote its 

 action on the muriat of soda. The remaining mass being dissolved 

 >and very slowly crystallized, assumed the form of clusters of regu- 

 lar prismatic efflorescent crystals of sulphat of soda, amongst which 

 scarcely any vestige of muriat of soda could be discovered. 



6. The decomposition of muriat of soda by the above process 

 being thus well established, it became necessary to determine the 

 proportions of sulphat and muriat of soda by some less direct method; 

 and the expedient which appeared the most appropriate was that of 

 inferring the point in question from a reference to the quantities of 

 acids as estimated in the preceding section. Thus as it was obvious 

 that, whatever the case might be with regard to sulphat of soda, the 

 presence of muriat of soda in the water was unquestionable ; and as 

 the whole quantity of muriatic acid discovered in the water (§ XIII, 

 2), corresponded to a quantity of muriat of soda which fell far short 

 of the sum total of alkaline salts, 1 naturally inferred that the whole 

 of the muriatic acid was united with soda, and that the water 

 must also contain a quantity of sulphat of soda sufficient to complete 

 the 20 grains of alkaline salts which the experiments just related had 

 shewn to exist in each pint of the water. 



2 if 



