398 Scientific Intelligence. (May, 
for the Mathematical Sciences; le Chevalier Cuvier, Perpetual 
Secretary for the Physical Sciences. 
V. Fermentation. 
Gay-Lussac conceives that during fermentation sugar is con- 
verted into nearly equal weights of alcohol and carbonic acid. His 
reasoning is as follows: sugar, he conceives, is composed by weight 
of 0:4 carbon and 0°6 water, or of 
1 volume vapour of carbon 
1 volume vapour of water 
or of......1 volume vapour of carbon 
1 volume of hydrogen 
1 volume of oxygen. 
Alcohol is composed of 
__ § 2 volumes vapour of carbon 
1 volume of olefiant gas = { 2 volumes hydrogen 
1 volume hydrogen 
4 volume oxygen. 
Let us triple all the elements of sugar to render the quantity of 
hydrogen the same in both, it will then be 
3 volumes vapour of carbon 
3 volumes of hydrogen 
3 volumes of oxygen. 
It is obvious that in order to convert sugar into alcohol we must 
withdraw 
1 volume vapour of water = 
1 volume of the vapour of carbon 
1 volume of oxygen gas, 
which, by combining, form 1 volume of carbonic acid. If we reduce 
these volumes to weights, we find that 100 parts of sugar are con- 
verted by fermentation into 51°34 alcohol and 48°66 carbonic acid. 
{See Annales de Chimie, xcv. 317, 
VI. Composition of Gum Tragacanth. 
According to Bucholz, gum tragacanth is composed of 
GOB eee Kyi geeie hb ayeiarb's)esn panne dele, iio ee 
sally cai viniags wiblonaie chs Belg ml ER, goose 
100 
The jelly is the substance which makes tragacanth swell when it 
is put into water. The gum is soluble in cold water, but not the 
jelly; but the jelly dissolves in boiling water, and then loses the 
property of gelatinizing. 
VII. Method of obtaining pure Sulphate of Manganese. 
I am not sure that Fischer’s mode of obtaining this salt in a state 
of purity is known to British chemists. On that account I shall 
