P1AT1NA. '243 



phthisis. The dose is from ^ to { of a grain, mixed with 

 sugar or formed into a pill with crumb of bread. According to 

 the French physicians, the best mode of exhibiting the salts of 

 <rold is by means of friction on the gums, and the chloride of gold 

 and soda is the preparation which ought to be preferred.* 



Chloride of Gold and Soda. — The following is the formula 

 for preparing this salt, which is given by Mr. Faraday in the Journal 

 of Science for 1816: — Dissolve 96 grs. of pure gold in nitro- 

 muriatic acid, evaporate and crystalize ; dissolve the crystals of the 

 chloride of gold obtained in distilled water ; add 30 grs. of decre- 

 pitated chloride of soda ; evaporate the solution and crystalize. 

 The crystals are long quadrangular prisms, of a fine yellow colour, 

 which deliquesce on exposure to the atmosphere. The chloride 

 of gold and soda may be used in the same manner and in the same 

 cases as the oxide and chloride of gold. The dose is from T V to 

 | of a grain, mixed with a little refined sugar. 



Ammoniuret of Gold. — This is a compound of ammonia and 

 the oxide of gold. It is prepared by adding liquid ammonia to a 

 solution of gold in nitro -muriatic acid, diluted with about three 

 times its weight of water ; a brown precipitate is formed, which, 

 if carefully dried at a temperature of k 212 c , explodes violently when 

 struck with a hammer, and is commonly called fulminating gold. It 

 was formerly employed, in very minute doses, as a remedy in some 

 convulsive diseases, particularly in chorea. When taken into the 

 stomach in too large a dose, the ammoniuret of gold causes 

 griping, diarrhoea, vomiting, great anxiety, fainting, convulsions, and 

 sometimes has proved fatal. f 



Genus II.— PLATINA. 



This metal is found in grains and rolled pieces, alloyed with 

 small portions of three other metals, viz. palladium, iridium, and 



* Orfila, ToxuolopUGenirule, i.r»3. t Wenk'l T»xkolo M ia. 



