LAMPIC ACID OF DANIELL IDENTICAL WITH ALDEHYDIC ACID. 167 
filled with ether, the aldehyde is retained in 
solution. If ammonia passed through a tube 
filled with fused potash and quicklime, is 
allowed to saturate the ether, the sides of the 
vessel are speedily covered with brilliant cry- 
stals, which are compounds of aldehyde and 
ammonia. Aldehyde may be also procured by 
distilling four parts of spirit of wine, six parts 
peroxide of manganese, six of sulphuric acid, 
and four of water. I'he receiver must be kept 
very cool, as aldehyde is extremely volatile. 
I'he process should be stopped whenever the 
product becomes acid, which happens when 
six parts have come over. 'I’his product mixed 
with its weight of chloride of calcium, is dis- 
tilled to three parts. The three parts are 
again rectified with their own weight of the 
chloride, when the resulting product is free 
from water and alcohol. It should then be 
mixed with twice its volume of ether, and 
saturated with a stream of ammoniacal gas, 
taking care to cool the receiver and to place 
between the vessel supplying the ammonia, 
and the ether vessel, a safety jar, so as to avoid 
tlie danger from the rapid absorption : Crys- 
tals speedily appear, which, when purified 
by ether, consist of ammonia and aldehyde, 
and are termed by Liebig, ommovial dehyde. 
The same compound may be obtained by pas- 
sing chlorine through dilute alcohol, distilling 
and rectifying over chloride of calcium, and 
saturating with ammonia. A considerable 
quantity of aldehyde is also formed by the 
action of spongy platinum upon the vapour 
of alcohol, as ascertained by Dbbereiner. 
Aldehyde is easily prepared, from its amrao- 
niacal combination, by dissolving two parts 
of the compound in its weight of water, and 
heating it, mixed with three parts of sulphuric 
acid and four of water, in a retort over a 
water-bath. The product is hydrous alde- 
hyde, which is rectified over chloride of cal- 
cium . It is necessary to cool the vessel when 
these two substances are brought in contact ; 
because, much heat is disengaged, and the 
aldehyde boils, when re-distilled, at a tem- 
perature of 86“. 
It is a colourless liquid, limpid like water; 
very volatile; sp. gr. *790 ; boiling point, 
7^1 at 28‘82 ; smell ethereal and peculiar. 
When its vapour is respired the power of 
breathing the air for some seconds is lost. It 
mixes in all propcrtions with water. It 
inflames readily. When mixed with spongy 
platinum, acetic acid is formed. It dissolves 
sulphur, phosphorus, and iodine, but without 
altering them, chlorine and Bromine are con- 
verted into muriatic and hydro-bromic acids. 
With nitric acid, acetic acid is formed ; with 
potash a reddish-brown resin is formed, which 
Liebig designates by the awkward name of 
Aldehy dharz . When aldehyde is heated with 
water and oxide of silver, the latter is reduced, 
and covers the inside of the tube with a metal- 
lic coat. Aldehyde consists of 
Carbon 5.5*024 Oxygen 35-993 Hydrogen 8*983 
'1 he derisity of its vapour is, by experiment, 
1-532, which corresponds with 
2 vols. vapour of carbon ..-8333= 1-5 
2 ,, hydrogen *1388 . .1388= -25 
5 ,, oxygen ..-5555= 1- 
Liebig gives its formula C4 Rs O. 
Ammonialdehyde crystallizes in acute rhom- 
bohedrons. 3'he crystals are colourless, pos- 
sess a hardness equal to sugar, and a smell 
like that of ammonia and turpentine ; they are 
volatile; inflammable; melt between 158® 
and 176®. 'I'hey have an alkaline re-action; 
they dissolve readily in water, with greater 
difficulty alcohol, and wdth difficulty in ether. 
With the acids and alkalies they act like alde- 
hyde and consist of Carbon 39'700 Oxygen 
25-969 Azote 22 987 Hydiogen 11 342 
100-000 
This is equivalent to 
1 atom aldehyde, C2 H2 0= 2-75 
1 atom ammonia N Hs =2-125 
I atom ammonialdehyde . . . 4-875 
Inflammable Gas. — The gas which comes over 
with aldehyde burns with a clear flame. It 
consists of carbon, 82-3; hydrogen, 17*6. 
When heated with perchloride of antimony 
(readily formed t'y passing chlorine through 
fused butter of antimony) olefiant gas was 
condensed in the form of the well-known oily 
chloride, and the remaining gas possessed all 
the properties of carburetted hydrogen. 
The products of the distillation of alcohol, ' 
sulphuric acid and peroxide of manganese, are 
carbonic acid, formic acid, acetic acid, alde- 
hyde, and traces of ether. 
With spongy platinum alcohol is converted 
into acetal, aldehyde, acetic acid, and acetic 
ether. 
Resin of Aldehyde is formed by the action 
of potash upon aldehyde. When the latter 
is introduced into a liquid containing alde- 
hyde, a brown colour is produced, and speedily 
brown flocks fall, when a weak acid or water 
is added. They consist of carbon, 73*340 ; 
oxygen, 18 “900 ; hydrogen, 7*759. 
Aldehydic dcid.— When oxide of silver is 
heated with a solution of aldehyde a soluble 
salt is formed, which is not an acetate, and is 
permanent when evaporated. I'his salt, when 
mixed with barytes water, is decomposed, 
giving off oxide of silver, and, when heated 
with the salt of barytes formed, produces pure 
acetate of barytes, and no other products: 
the oxide of silver being completely reduced. 
A similar result is obtained by the action of 
ammonialdehyde upon oxide of silver. 
From Liebig's experiments it appears tha^ 
the formula of aldehydic acid is, C4; H3 02 , 
and, therefore, a true acetous acid ; the com- 
postiton of acetic acid being H3 03. He 
considers the lampic acid of Daniell to be 
identical with aldehydic acid, d he combina- 
tions may be explained in two ways, accord- 
ing to Liebig : 
1st, Aldehyde may be considered as alcoho| 
deprived of an atom of hydrogen, and alcoho* 
as a hydrate of ether; or, 2nd, Aldehyde may 
be a deutoxide of binolefiant g-as. The for- 
mulae will, therefore, be, 
1st, Unknown compound of carbon 
and hydrogen. . .. C4 H3 
Aldehyde..' H3 O + HO 
Aldehydic acid . . . . C* H3 02 4-. HO 
Hydrous acetic acid Hs 03 HO 
1*5276 2-75 
