86 
Miscellany. 
are transformed into oxalic acid, and at a higher heat, into carbonic acid. 
This is the case with sawdust, cotton, starch, gum, tartaric, citric and 
malic acids, silk &c. Some vegetable substances give out hydrogen and 
carbonic acid at the same time ; and animal bodies, in addition to these 
two, afford ammonia and cyanogen. It is remarkable, that tartaric acid 
disengages scarcely any hydrogen, and does not become blackened. Tar- 
tar may be transformed into oxalate of potash by a very simple process ; 
this consists in dissolving the tartar in water, with a suitable quantity of 
potash or soda, and forcing the solution by means of a pump, into a thick 
tube of iron or brass, heated to 400° F. The pressure would be but about 
twenty-five atmospheres, as no gas is disengaged. 
Ann. de Chim. 
Cause of Crystallization. M. Gaudin, in his investigations on the pro- 
perties of atoms, has been led to some interesting conclusions. Accord- 
ing to him, those bodies crystallizing in a cube have for their primitive 
molecule a point or right line ; either an atom, as in metals ; two dis- 
similar atoms, as in sulphuret of lead ; three atoms, one of one kind, and 
two of another, as chloride of sodium ; again, those molecules having for 
their form a double simple pyramid, or a prism of a number of sides, 
which are a multiple of forms, may be assimilated to points, when under 
different circumstances the} 7 form in groups around an accidental nucleus, 
and in this way sometimes crystallize in cubes. Those bodies whose 
cleavage gives a right prism, with any base whatever, have for their 
primitive molecule, either the polygon of the base, or a double simple 
pyramid, or a prism of a number of sides, equal or double. When the 
primitive prism is not cleavable perpendicularly at the axis, it is because 
the molecules are polarized, that is, retained together either by an 
electric force, or by the force of affinity. The tetrahedron, octahsedron and 
rhomboihedron, have respectively for their primitive molecule, the first a 
square, or a rhomb, the second a double tetrahedral or octahedral pyra- 
mid, either simple or with an intervening prism, and the third a double 
hexahedral pyramid of the same nature. Finally, the absence of cleav- 
age in these bodies is owing to want of continuity of the molecules. But 
in the tetrahedron, the want of continuity depends solely on the state of 
polarization, whilst in the octahedron and rhombohedrcn, it results from 
the aggregation of the molecules. Journ. de Chim. Med. 
Citrate of Quinine. Dr. Galvani gives the following process as afford- 
ing a pure article. One part of sulphate of quinine is to be dissolved in 
forty parts of pure boiling water, and acidulated citrate of soda, added 
gradually to the solution ; at first litmus paper is not reddened by the 
liquor, but on the addition of more of the citrate, that paper is changed to 
