38S Walen of Baden. — Distillation of Sea IVater. 



I shall feel particularly obliged to any of your correspondents 

 who will inform me whether any experiments on felspar have 

 given results favourable to tiie above hvpothesis. 

 i am, sir, yours respecfully, 



LiTHOPHlLUS. 



P.S. In the Nlviiith volume of the Philosophical Miigazine you 

 have affirmed that the Waterloo or Strand Bridge is evLlre.Ly con- 

 structed of granite. This is not exactly the case, as, though gra- 

 nite is by far the predominating material of that structure, it 

 contains a considerable quantity of re J calcareous gritstone, and 

 of white, laminated, micaceous sandstone. 



*.^;* Our correspondent is right respecting the materials of the 

 Strand Bridge : but we meant only that the principal material 

 was granite; everv part of t'.ie visible exterior of the structure is 

 composed of that species of stone. — Editor. 



WATERS OF BADEN. 

 M. Gimbcrnat has found on analysis, that the gas of these ce- 

 lebrated waters is not, as has been generally believed, carbonic 

 acid, but azote. By collecting and condensing the vapours which 

 rise from the principal spring, he has obtained a mineral water 

 which differs essentiallvin its chemical properties from the water 

 which issues from the rock. It is more gaseous, and more im- 

 pregnated with animal principles ; whence ]\i. G. believes it will 

 be found even more salutary than the baths themselves, into 

 which the v;ater does not flow till after a great portion of its vo- 

 latile properties has evaporated, in consequence of its high tem- 

 perature, and its exposure to the air. In this opinion he has been 

 confirmed bv the singular fact, that the whole interior of the 

 chimnev above the spring, and through which its vapours have 

 passed from time immemorial, has become covered with a thick 

 and greasy tegument, which is evidently of a vegeto-animal na- 

 ture, and proves the sanatory quality of gas volatilized by thermal 

 heat. 



DISTILLATION OF SKA WATER. 



M. Freyconet, to whom the King of France lias given the com- 

 mand of a scientific expedition, which is preparing to proceed 

 round the world, being convinced from experience of the fitness 

 of distilled sea-water for all potable purposes, has furnished his 

 vessel with a sfill capable of supplying water to the whole crew, 

 consisting of 120 men. On a trial of this still, which was made 

 in presence of a connnittee apjiointed by the minister of marine, 

 it was found that by one killogram (two pounds) of coal they 

 could obtain (rJS killograms (loj pounds) of fresh water of 

 good quality. The water had at first an empyreumatic taste^ 



but 



