ya Salt-Werh •without Hfat.— 'Terra AuJraUi, "" 



trlvance, and endeavoured, though at that time without fuccefs, to carry It into effeft. I 

 apprehend that his refcrvoir may not have been fufficiently capacious. Attempts have 

 been made in England, to render the a£tion of fmall ftreams more Ready and conflant by 

 the intervention of a refervoir, which fliould retain a large portion of the water when wet 

 weather rendered it plentiful, and fupply the defeft at fuch times as the water failed for 

 want of fuflicient rain. 



6. An experiment has been made in the large way at the fall-work of Artern, fituated ia 

 the circle of Thuringia, dependent on the ele£lorate of Saxony, on the poflibility of obtain- 

 ing fea fait merely by the heat of the fun, after having brought the fait water to as high a 

 degree of concentration as the procefs of graduation is capable of affording. This fait work 

 was the firft eftabliftiment of the kind in Saxony, by Mr. Borlach, to whom the undertakings 

 of this nature are fo much indebted ; and it will probably have the honour of being the firft 

 in which this new procefs fhall fucceed. Experiments on a fmaller fcale have already af- 

 forded the highefl hopes of fuccefs. Thofe which have been attempted in the large way, 

 though at the end of the warm weather, have afforded encouraging refults. 



For this purpofe a number of veflels of wood have been placed in a field upon polls, at 

 the height of five or fix feet from the ground. They can be covered or uncovered in an 

 inftant by a moveable roof made of thin boards, accordingly as the weather is clear or 

 rainy. Though the fummcr was nearly over when the experiments began, fait was obtained 

 in this manner by the mere heat of the fun ; and this fait was much purer, and of a more 

 lively and agreeable tafte, than that which is obtained by evaporation in boilers. There is 

 every reafon to expeft that the whole of the fait which can be obtained at thefe works, will 

 be feparated in this manner without the ufe of any combuftible. A great number of thefe 

 cafes are accordingly prepared, to give all the necefTary adlivity to this method of operating 

 next year. 



Citizen Charles Coquebert, in a note on this fubje<5t, remarks that the celebrated 

 Haller publifhed, in the Memoirs of the French Academy for the year 1764, a fet of expe- 

 riments on the evaporation of falt-waters made at the works in the canton of Berne, of 

 which he was the direflor; and adds, that the experiments are interefting, but that the eco- 

 nomical calculations are grounded on fuch erroneous foundations, that they would ferve only 

 to miflead thofe who from the reputation of the author might ufe his calculations relative 

 to any undertaking in the large way. 



V. 



An Attains of the Earthy Suhflance from New South Wales, called Sydneia^ tr Terra Atijl rails. 

 By Charles Hatchett, Efq. F.R.S.* 



I 



N I'pfij tbc Right Hon. Sir Jofeph Banks, P.R.S. favoured me with a fpecimen of the 

 Sydneia, which had been lately brought to England. A portion of this I foon after examin- 

 ed, 



• Fr«in the Philof. Tranf. 179S. The introduftory part of Mr. Hatchett's paper concifely ftates the refults 

 »f Wedgwood'i paper (from which an eztraft i« copied in Philof. Journ. 1.405); — that ProfeiTor Blumenbach, 



