i*22 On the Density of frozen Mercunj. 



waste of spirits ; but now it may be remarkably improved 

 immediately by measures which prevent the above conta- 

 mination; and the first of these is the abstraction of the 

 putrefactive niattcf by filtration, and the immediate con- 

 veyance of the clear warm fragrant iiqiiOr to the working 

 cistern, there to undergo the most timely and productive 

 fermentation, and to sufler the least defalcation of r^pirit by 

 fotrl scum and bottoms, which are generally thrown away. 



Another source of the contanjination is in the empy- 

 reuma; but as this regards the distillation as well as the er- 

 rors in making sugar, it is unnecessary to sav more of it at 

 present than that the prescribed measures, together with a 

 judicious setting and management of the still, will totally 

 prevent the empyreumatic smell and taste. 



LVII. Letter of M. Tardy de La Buossy to Professor 

 PlCTET, vf Geneva, upon the Experiments of Mr. Bid- 

 3DLE, relative to the Density of frozen Mercury*. 



JoVeuse (Ardechc), 

 SIK, Oct. 1:J, 1805. 



J. HE e.\'ptriments of Mr. Biddle (vol. xxxix. p. 21 7 f), in 

 order to determine the density of solid mercury, having at- 

 tracted my attention, I cannot pass over in silence the se- 

 rious objections to which the results of the above gentleman 

 are liable. In communicating them to you, I am well per- 

 suaded that I shall enter completely into yo^ur views, which 

 have equally for their objects the extension of truth and the 

 removal of error. 



Mr. Biddle, after having made known the process which 

 he followed and the precautions taken by him, informs us, 

 that a thousand grains of mercurv made solid at the 40th 

 degree below the zero of Fahrenheit (— 32 of Keauniur), 

 experienced, when weighed in alcohol of the same tempe- 

 rature, a loss in weight of 5y8 grains. 



A thousand grains of pure silver, weighed bv tin- sanif 



* From B'll-liiithcquv Brit.inriqitc, vol. iii. 

 •♦■ /Vtfr Nif 'iiolson's Journal iiir April iL'.Oj. 



balancr. 



