Intelligence and Miscellaneous Articles. 83 
is disengaged, and a very minute portion of azote is absorbed.— 
Journal de Chimie Médicale, Oclobre 1835. 
_— 
ALDEHYD—A NEW COMPOUND. 
This substance, composed of hydrogen, carbon, and oxygen, was 
discovered by M. Liebig ; it was procured by distilling with a gentle 
heat a mixture of, 
Alcohol (80 per cent. real) ...... 4 parts 
NOEED at. « Cet oles MiieEY haeieis on, ote 4 do. 
BSPNBCU ACAD occ cic cea re cba ae oie a 3:2 6 do. 
Peroxide of manganese ......... 6 do. 
Aldehyd, mixed with alcohol and some other products, comes over, and 
some carbonic acid is disengaged. As the new product is extremely 
volatile, the receiver must be kept very cool to prevent the great loss 
of it which would otherwise occur. When about six parts have been 
distilled, they. are to be withdrawn and redistilled, mixed with an 
equal weight of well-dried chloride of ealcium, from a retort in a salt- 
water bath ; when three parts have come over, these are to be again 
distilled with an equal weight of chloride of calcium, and then one 
part and a half, which is aldehyd, completely free from water, and 
partly so from alcohol and ether, is to be distilled. To this aldehyd 
its volume of zther is to be added, and ammoniacal gas is to be passed 
through it to saturation, taking care to surround the vessel with cold 
water, on account of the great heat disengaged. It is requisite to 
place a safety bottle between the vessel from which the ammonia is 
evolved and that which contains the aldehyd and ether, in order to 
prevent the passage of vapour of the aldehyd into the apparatus used 
for disengaging the ammonia, the absorption of this latter gas being 
so extremely rapid, that it would be impossible to prevent its rise. 
As the absorption of the ammoniacal gas proceeds, the liquor becomes 
turbid, and numerous transparent colourless crystals are precipitated, 
which are a compound of ammonia and aldehyd; these are to be 
purified by two or three washings with ether ; they are then to be 
dissolved in an equal weight of water, and to the solution is to be 
added a mixture of three parts of sulphuric acid and four of water. 
At a gentle heat the aldehyd distils with brisk effervescence, and the 
operation ought to be stopped as soon as the water in the bath begins 
to boil ; the aldehyd comes over mixed with water, and is to be re+ 
distilled with an equal volume of chloride of calcium in large pieces ; 
surrounding the apparatus carefully with cold water, on account of 
the heat generated by the union of the aldehyd and chloride: tne 
product is to be again distilled from a salt-water bath with chloride of 
calcium in powder, and the aldehyd has then the following properties : 
it is liquid, colourless, transparent ; its odour is ethereal and suffoca- 
ing, and its specific gravity is 0°790; it boils at 71+24 Fahr.; it combines 
with water in all proportions, much heat being evolved ; if chloride of 
calcium be added, the aldehyd separates and floats on the surface ; it 
combines in the same way with alcohol and with ether ; its solutions 
produce no change on vegetable blue colours ; it is very inflammable, 
burning with a blue flame ; if it be kept in a bottle containing air, it 
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