SCIENTIFIC SUMMAEY. 
189 
The Chemical Properties of Nitro- Glycerin have been thus defined by 
M. F. Tilberg. Nitre-glycerin (from the works at Stockholm) is decomposed 
when acted upon by potassium hydrate j amongst the products of decom- 
position are potassium nitrate, glycerin, ammonia, cyanogen, oxalic, humic, 
and nitrous acid. When ignited in a vacuum with copper oxide and copper, 
two volumes of carbonic anhydride and one volume of nitrogen are obtained, 
from which numbers the formula G 3 H 5 (N 02)30 is deduced. Nitro-glycerin 
dissolves in concentrated sulphuric acid, forming with it a new compound acid 
which yields crystalline salts. A combustion gave three volumes of carbonic 
anhydride to one volume of nitrogen. If nitro-glycerin is regarded as a sub- 
stituted glycerin, and the relation between it and the new acid the same 
as that between glycerin-sulphuric acid and glycerin, the new compound 
will be dinitro-glycerinsulphuric acid. — Oefvers. af Ahad. Fdrh.j 1868, 25, 
No. 2, 75 ; and Journal f. Ch. cv. 254 ] and Chemical News, Jan. 8. 
Preparation of Ellagic Acid hy means of Gallic Acid. — By heating (says 
M. J. Lowe, in the Chemical News, Jan. 22) nearly to the boiling-point for 
several hours in an aqueous solution of two equivalents of gallic acid and 
one of arsenic acid, a crystalline precipitate is deposited, which is none other 
than ellagic acid ; the best way is to mix the two acids in the proportion 
indicated above, add water, evaporate to dryness, heat in an air-bath to 120° 
and extract with alcohol at 90°, which does not dissolve ellagic acid. The 
reaction is the following — 
^28^12020 + 20 = CggHgOjg + 6HO. 
In commercial tannin there is always gallic acid, and consequently ellagic 
acid proceeds from it. A cold extract of oak bark gives by degrees a yellow 
deposit of ellagic acid, and it is, indeed, this same acid which constitutes 
that gelatinous covering which is formed over tanned hides. 
Extraction of Sugar from Molasses. — At a recent meeting of the French 
Academy M. Dumas exhibited some crystals of sugar extracted by a process 
of M. Margueritte’s from molasses. M. Margueritte has been enabled to 
extract from 100 kilogrammes of molasses 35 to 38 kilogrammes of true 
sugar, which brings up the total product of the beet-root to 25 per cent. 
M. Margueritte treats the molasses by alcohol at 85 degrees, which dissolves 
the sugar. He also obtains a supersaturated solution of sugar. By project- 
ing powdered sugar into this solution it crystallises, and nearly double the 
weight of sugar introduced into it is obtained from it. This sugar only con- 
tains one-hundredth part of impurity, and can consequently be immediately 
subjected to the refining process. — Vide Comptes-Pendus, Feb. 21. 
Carhonic Acid decomposed hy Plants. — From a large number of experiments 
recently made, M. Boussingault concludes that the chlorophyll is the agent 
of decomposition, and he states that wherever the chlorophyll exists it has 
the power of decomposing carbonic acid. 
The Chemical Food of Plants — In the Comptes-Pendus (March 1) M. Peli- 
got has a note on the employment of sea- salt in agriculture which relates to 
this subject. M. Peligot thinks that scientific agriculturists labour under 
delusions in reference to the action of salt ; he believes that in the case of 
impermeable soils, through which water passes slowly, the influence of salt 
is more hurtful to crops than beneficial. Analyses have shown him, con- 
