-58 Of the hifluence of Solar and Lunar 



The committee carefully repeated the experiments de- 

 tailed in the above memoirs. Jr' we except the whitening 

 effects on exposing the acetate to the sun, which did not 

 succeed with them, they pronounced them to be all cor- 

 rect ; indeed, the principal agent in the. whitening process 

 was already known. Lowitz has recommended the use of 

 charcoal, in order to obtain an acetate of potash less coloured 

 than by the ordinary process ; but whether he has not suffi- 

 ciently described the method of using it, or employed vine- 

 gar of a bad quality, ill distilled or ill saturated, over which 

 the depurating qualities of the charcoal had no influence > 

 several chemists have been unsuccessful. 



From these considerations, and particularly from the sa- 

 tisfactory results obtained by the committee, they think 

 themselves warranted in concluding, that the authors of the 

 two memoirs would have done better by making known the 

 principle and the causes of the colouring of this salt, at the 

 same time that thev indicated the means of preventing and 

 removing them. 



By following carefully the rules which they prescribe, 

 and by taking all the precautions which they point out, 

 we shall easily obtain, without having recourse to fusion, 

 an acetate of potash very white and perfectly saturated. 

 The society has therefore decreed a gold medal of the 

 value of 100 francs to each of the authors of the memoirs. 



The author of the memoir first mentioned is M. Ber- 

 noully of Bale; and of the second, M, Fremy of Versailles. 



VIII. Of the Influence of Solar and Lunar Attraction on 

 Clouds and Vapours, By Salem Harris, Esq, 



To Mr. Tdloclu 



Sir, In perusing the theory of the tides as originally laid 

 clown by Kepler, and subsequently improved upon by Sir 

 Isaac Newton, I was forcibly struck with an idea, that if 

 the attraction of the sun and moon (more particularly the 

 latter) is capable (as the ebb and flow of the sea appears to 

 have proved beyond dispute) of acting with sufficient 

 power upon that immense and ponderous mass the ocean, 

 to raise its waters on those parts which the revolutions 

 of the heavenly bodies alternately place in the focus of 

 their attraction ; its effects upon the clouds, the lighter and 

 exhaling particles, or comparatively speaking the steam of 

 those waters-, must be still greater; and sufficient to pro- 

 duce, in conjunction with or opposition to the wind, those 

 frequent and apparently uncertain changes which we. 



hourly 



