136 Scientific Intelligence. [Fkb. 



If I remember right, Wedgewood's clay pieces were baked in a 

 red beat. If this be the case, it is impossible that the boiliog point 

 of mercury, which is below the commencement of Wedgewood's 

 scale, can be repcesented by 2° of that scale. There is reason to 

 believe from tliis, that Morveau was not in possession of the true 

 clay pieces of Wedgewood. If so, his determination of the value 

 of Wedgewood's degrees cannot be con-idered as correct. The 

 melting point of tin is certainly stater too high in the preceding 

 table. Mr. Crighton of Glasgow, whu^e accuracy is uncommon, 

 found that this metal melts at 442'^, and that it melts at a lower 

 temperature than bismuth. 



XI. Saccharomeler. — Tkermomelt : — Slarch-Sugar. — Passage oj 



Air tkr^'igh Tubes, 



(To Ur. ThomsoB.) 

 SIR, 



I beg to make some observations on the queries in your Ammls, 

 of September, respecting the use of the saccharometer in brewing, 

 which I had delayed. 



According to the common acceptation of the word strength, in 

 beer or ale, the saccharometer foretels it sufficiently near the truth, 

 for similar processes in the savie brewbouse ; but it is not a sure 

 guide for any dissimilarity in the mode of brewing or of drawing 

 the extract : for then the constituents of malt are no/ often dissolved 

 in the same proportion to each other ; and, in all cases, the extracts 

 are superior in value according to their priority. For, let the first, 

 from the same parcel of malt, be reduced to the specific gravity of 

 the last, and equal quantities of each will give a beer or ale very 

 different in quality. 



The quantity of alcohol increases during fermentation, as the 

 specific gravity of the fermenting fluid diminishes, but in what ratio, 

 no correct experiments have as yet ascertained. The term, desig- 

 nated strength, in malt liquors, depends, however, on many inex- 

 plicable circumstances; I fancj', from the variety in quality in 

 different beers, made from equal extracts in every respect. I do 

 not mean to allude to the mixture of any deleterious drugs, because 

 I really believe the common brewers, in general, do not, and those 

 extensive establishments in London, cannot, make use of any sub- 

 stitute for malt and hops. The gentleman, who makes those 

 queries. Is perfectly correct in asserting, that the common saccha- 

 rotneters do not give the quantity of solid matter contained in a 

 barrel of wort; they express merely the dificrence of weight 

 between that and a barrel of water. The former, however, can be 

 ascertained nearly by multiplying the latter by 2, 7? according to 

 my trials, which I Ivope agree with the experiments of this gen- 

 tleman. 



It is rather a disgrace to the present state of chemistry, that tlie 

 chemical brothi^rhood of Europe should still suffer the variety in the 

 t'liern.o.netric scale to exist ; 1 therefore, as an humble individual, 

 beg to suggest, that a resolution, published by the leading chemists 



