148 Oxalic Acid,-^Fennentallon, — Celesllne. 



the moment these combinations are broken. Oil of vitriol is also 

 a good reactive, not only to discover the oxalic acid, but also to 

 determine the affinity; for the citric, tartaric, &c. acids, being 

 put in contact with the sulphuric acid at the ordinary tempera- 

 ture, do not give any gas. 



New experiments on fermentation have convinced M. Dobe- 

 reiner that the smallest parcels of sugar concealed in any licjuid 

 may be discovered, and their affinity determined, by adding to 

 such liquid some grains of yeast and inclosing the mixture in a 

 vessel sealed with mercury. The fermentation, which at the tem- 

 perature of from 15 to 20 degrees R. begins to manifest itself, and 

 continues as long as any sugar remains, occasions the disengage- 

 ment of a quantity of bubbles of carl)onic acid gas, from which 

 the quantity of sugar which the yeast has decomposed may easily 

 be calculated. M. D. has found that five grains of sugar, dis- 

 solved in a half cubic inch or in a whole cubic inch of water, and 

 put in contact with some grains of yeast, uniformly resolve them- 

 selves into 4 7 cubic inches of carbonic acid gas and '2"57 grains 

 of alcohol. He considers the sugar to be a saline compound 

 formed of three affinities, or 3 x 7'7 of deutero-hydroid of carbon, 

 and three proportions, or 3 x 20-7 of carbonic acid. Alcohol ac- 

 cording to him is composed of three proportions of deutero-hy- 

 droid of carbon and a proportion of carbonic acid. 



You know that in the vicinity of Jena, celestine is met with iu 

 great quantities, M. Doberenier has had occasion to ascer- 

 tain by a long series of experiments the slaccMometriqne value 

 of strontian. He has found that the number representing that 

 earth is 50, the hydrogen being 1 and the oxygen 7'5 ; Ijut this 

 number is exactly the arithmetic mean of those which represent 

 the stacchiometriqiie value of lime (27'5) and of barytes (72-5), 



he. ^~~ = '^^- M. Dobereiner was doubtful for a time 



as to the existence of strontian ; but this has satisfied him as 

 well by synthetic as analytical experiments. A circumstance 

 still more remarkable is, that the specific weight of sulphate of 

 barytes (celestine) is also the arithmetic mean of that of pure 



sulphfite of lime and of spath, viz. 1 =3'65 ; which is still 



a further proof that celestine is a mixture of equal stacchiome- 

 trique parts of anhydrite and spath. 



I ought not to omit that M. Dobereiner has discovered a 

 considerable quantity of sugar in the aqueous extract of the root 

 of the calamus, obtained by the aid of a filter-press of Real. 

 Fromsdorflf, in his analysis of the same root, speaks only of a 

 sweetish extract, which he describes as insusceptible of fermen- 

 tation. 



TEST 



