, EtrLORESCENCES OF WALLS. HI 



charaders of the faline efflorefcence from the ftable, and when of foda nearly 

 fubmitted to the fame chemical re-agents, differed from ii^'^'^^' 

 only in exhibiting flighter traces of the muriatic acid ; this 

 fait was therefore a fulphate of foda nearly in a ftate of 

 purity. 



The walls of the fait water baths in this town are covered Fourth effloref- 

 with a ftucco, which is in feveral places bliftered and moulder- ^^"^"^ oTa'fea- 

 ingaway. The parts of the plaifter which are decaying, are water bath, was 

 covered with a copious efflorefcence, which has the appear-'"''""'**^ <'^'°'^*» 

 ance of a fine white down. Some of this I colledted and 

 examined. It was diffolved in warm water and filtered ; the 

 folution was not capable of being regularly cryftallized, but 

 formed a white mafs, eafily foluble, polfefling the acrid tafte 

 of a fixed alcali, and affeding the colour of tefl papers in the 

 fame manner. A brifk efFervefcence was excited by the ad- 

 dition of an acid, and from this circumflance and the effied of 

 the different re-agents, I conceived it to be one of the fixed 

 alcalies. In order to determine whether it Was an uncom- 

 bined alcali, and to which of thefe bodies it ought to be re- 

 ferred, I afcertained what quantity of the fulphuric acid was 

 requifite to faturate a known weight of the fait, and after- 

 wards, employing the fame acid, compared it with the quan- 

 tity which the fame weight of alcali required. As the fait 

 had not attraded any moiflure from the atmofphere during a 

 period of fome weeks, I eoncluded it to be foda, and I ac- 

 cordingly found that the fame quantity of fulphuric acid fafu- 

 rated equal weights of foda, and of the fait under examina- 

 tion; the folution being flowly evaporated, formed well- 

 marked cryflals of the fulphate of foda. That part of the 

 walls of the bath on which the fait had efflorefced in the 

 greateft quantity, was out of the reach of the immediate 

 adlion of the fea water ; but it is probable that tlie fand of 

 the Ihore had been mixed with the lime, for by examining a 

 quantity of water which had been digefi-ed upon a portion of 

 the plaifler, it yielded a very copious precipitation by the ni- 

 trate of filver, and this rendered it highly probably that the protably formed 

 mortar contained the muriate of foda. It might therefore be by procefs for- 

 conjedured that the foda in this cafe was accidentally formed fj^^^^^ mxei. 

 by the fame procefs which, according to Mr. Accum's sCcount 

 in the 2d vol. of the Journal, p. 24'3, is employed defignedly 

 in PfuHia for obtaining it, by the decoropofition of common 

 fait. 



I fhall 



