Manufacture of Neutral Aluminium Salicylate and of a Soluble Compound of the same.
Year: 1893

page_text: Date of Application, 9th June, 1893-Accepted, 2nd Sept., 1893
Manufacture of Neutral Aluminium Salicylate and of a Soluble
Compound of the same.
I, JASPER WETTER, Patent Agent, of 433 Strand, in the County of London,
do hereby declare the nature of this invention and in what manner the same is to
be performed, a communication from the Firm of J. D. Riedel, Manufacturing
Chemists, of Gerichtstrasse, Berlin, in the German Empire, to be particularly
described and ascertained in and by the following statement :-
Hitherto the utilization of a whole series of salts of alumina with organic acids,
for therapeutic purposes, has been hindered by the fact, that the composition of the
said compounds as hitherto produced, has not been uniform, and that in the shape
of insoluble precipitates they have been suitable for therapeutic purposes to a very
limited extent.
With regard to one of these salts, the aluminium salicylate, which hitherto has
only been described as a precipitate of variable composition, my correspondents
have ascertained, that it can be easily obtained of a constant composition, in the
shape of a neutral compound containing for one molecule of alumina six molecules
of salicylic acid.
Moreover, by treatment with ammonia, they have succeeded in converting the
insoluble neutral aluminium salicylate thus obtained into an easily soluble and
likewise uniform (as regards composition) ammoniated double salt.
The composition of the compounds obtained, when anhydrous, is as follows ;—
Found by analysis
Calculated for A₁₂(CH
). + 3 aq.
coo
Al,O, 10.88 per cent.
10.97 per cent.
ALUMINIUM SALICYLIC. AMMONIATUM.
1. Dried in the atmosphere (air dry);
1.6220 grammes yielded 0.1620 grammes of Al,O,.
2. Dried in the exsiccator;

page_text: MINIUM
Dissolve 6.65 kilos. of aluminium sulphate, Al,(SO), + 18 aq. (or 9.48 kilos. of
crystallized potash-alum) in 100 kilos. of water, filter, and pour the liquid into a
solution of 96 kilos. of sodium salicylate in 100 kilos. of water.
After the crystalline precipitate thus obtained has been allowed to stand for
some time, draw it off by suction and wash again with water, until the filtrate
contains only traces of sulphuric acid. Subsequently dry the mass at about 50° C.
.II. PRODUCTION OF ALUMINIUM SALICYLICUM AMMONIATUM.
a. Mix 10 kilos. of aluminium salicylic. neutrale with 20 kilos. of water, and add
gradually, while stirring, 5 kilos. of spirit of sal-ammoniac of 0.910 specific gravity..
Filter the reddish yellow liquid thus produced, and evaporate it to dryness on a
water bath, at a temperature not exceeding 60°.
b. Expose 10 kilos. of aluminium salicylicum neutrale to the action of gaseous
ammonia in a suitable apparatus, until the original reddish white turbidity of the
mass has changed to a uniformly yellow tint and a sample (even after its excess of
ammonia bas been removed over sulphuric acid) forms with water a clear solution.
The aluminium salicylicum neutrale, shortly called "salumin," is a fine crystalline
and slightly reddish powder, insoluble in water.
The aluminium salicylicum ammoniatum, shortly called by the manufacturer
"salumin solubile," is a yellowish white powder, easily soluble in about 9 parts of
water, and still more easily soluble in glycerine diluted with water.
have a neutral reaction.
The solutions

page_text: The new alumina salts combine the effects of aluminium with those of salicylic
acid and are suitable for therapeutic applications.
The soluble ammonium compound has a much more marked therapeutic effect
than the insoluble salt.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The manufacture of neutral aluminium salicylate by adding aqueous solutions
of aluminium salts to solutions of alkali salicylates at a medium temperature and in
such proportions, that for each molecule of alumina there are 6 molecules of
salicylic acid taking part in the reaction, substantially as described.
2. The manufacture of a soluble ammoniated double salt of the neutral alumina
salicylate obtainable as specified under 1, by treating the latter with gaseous or
liquid (aqueous) ammonia in the proportion of 1 molecule of the insoluble salt to
6 molecules of ammonia, substantially as described.
3. As a new article of manufacture, aluminium salicylicum ammoniatum, having
the composition and properties substantially as described.
Dated this 9th day of June 1893.
FAIRFAX & WETTER,
433, Strand, London, Agents.