ARTIFICIAL ULTRAMARINE. 
105 
marking ink, which I think will be found to realize all the 
above conditions ; it is thus prepared: — 
p. Nitrate of Silver gj. 
Carbonate of Soda, crystallized, giss. 
Tartaric Acid 9ij- 
Strong Liquor Ammoniae f.^ij. or q. s. 
Archil f.gss. 
White Sugar 3iv. 
Powdered Gum Arabic 3xij. 
Distilled Water q. s. 
Dissolve the nitrate of silver and carbonate of soda sepa- 
rately in distilled water : mix the solutions: collect and 
wash the precipitate on a filter ; introduce the washed pre- 
cipitate, still moist, into a Wedgewood's-ware mortar, and 
add to it the tartaric acid, rubbing them together until 
effervescence has ceased; add liquor ammonias in suffi- 
cient quantity to dissolve the tartrate of silver; then mix 
in the archil, white sugar, and powdered gum arabic, and 
add as much distilled water, if required, as will make f.gvj. 
of the mixture. 
It will be observed that the essential difference between 
this formula and those which have been already published, 
consists in the use of tartrate of silver, instead of nitrate of 
silver. — Pharm. Journ. 
ART. XXXIV. — ARTIFICIAL ULTRAMARINE : ITS COMPOSI- 
TION AND CHEMICAL PROPERTIES. 
Ultramarine, whether native or artificial, always con- 
sists of silica, alumina, sulphur, and a little oxide of iron ; 
but no two specimens contain these substances in the same 
VOL. XIII. — NO. II. 10 
