A Manual of the Chemistry of the Carbon Compounds

THE CARBON COMPOUNDS. 867
7 DiamMobtwxnc Add crystallizes in long yellowish-white needles,
and forma an almost insoluble sulphate 2[C9H8(C0jH)(NHi)g]SO4H,
.+ 1^0.
The /3 and y acids yield, when heated, utetadianidobenixne (page
327).
8 Diamidotenzoic Acid.—This body has been obtained by reducing
dinitrobenzoic acid. It differs from its isomerides by its physical
properties, as well as by not yielding a diamidobenzene, being by
beat completely carbonized, with the evolution of ammonia.
MpMemnc Add C6H41 ^^.—This strong bibasic acid is
formed by passing gaseous sulphur trioxide over benzoic acid. It is
a crystalline, very deliquescent, sour mass. The neutral barium salt
is freely soluble in water, but the acid salt (C^SO^BaCCOjHJj,
which crystallizes in monoclinic prisms, dissolves but sparingly.
Distdplwbinzoic Add CeHg -I >?Q S J?'»is obtained by heating benzoic
acid with fuming sulphuric acid and phosphorus pentoxide to 250°.
It forms hygroscopic crystals. The acid barium salt C6Ha j g^^
+ 2H8O, is sparingly soluble in water, and forms microscopic needles;
the normal salt ^[CgTUSOj^COJBftj + 7H2O, crystallizes in priams.
The lead-salt is insoluble in water.
OXYBENZYL- AND OXYBENZOYL-COMrOUNDS,
The compounds belonging to this group contain one or more
hydroxyls, combined with the aromatie nuoleus, and have therefore
the character of phenols.
f OH
Saligenin, or 1-2 Oxybemyl Alcohol C6H4 i XJJ QH*—"^ e ^ ^ °^
*"f OH"
different kinds of willow contains Salicin C^H4a
glucoside which, by the actions of certain ferments, takes up water,
and is resolved into saligenin and grape-sugar.
Saligenin crystallizes from alcohol or hot water in brilliant, small,
rhombic plates, melting at 82°, and subliming above 100°, Its aqueous
solution gives with ferric chloride a deep-blue colour. Oxidizing
agents convert it into salicyl aldehyde and salicylic acid. Saligenin
is isomeric with orcin and homopyrocatechin, and metamerio with
guaicacol:—