VIII. ACIDS. 291 



ensues, the liquid must be filtered, and the phosphate of quina 

 must be speedily washed with cold distilled water. 



loDATE OF sTiiYCHNiA. Obtained by saturating a concen- 

 trated solution of powdered strychnia with iodic acid, on which 

 the mixture swells, absorbs the water, and becomes thick : treat the 

 mass with boiling alcohol, filter and leave to evaporate : the result 

 is a beautiful crystallization of iodate of strychnia. It may also 

 be got by the double decomposition of a salt of strychnia, and 

 some soluble iodate — muriate of strychnia and iodate of soda for 

 :istance. Iodate of strychnia is white, crystallized in beautiful 

 prismatic needles, is slightly soluble in cold water, very soluble 

 in hot water and in alcohol. Has been found serviceable in para- 

 plegia ; it may be given in pills of one eighth of a grain each, 

 one at night and the other in the morning, and the dose is 

 increased gradually until eight are taken in twenty-four hours. 



Sulphate of stkychnine. Dissolve strychnine in dilute 

 ulphuric acid, evaporate and crystallize ; proposed to be 

 employed, or any other salt of strychnine, when the system is 

 accustomed to the action of pure strychnine, but not in use. 



Sulphate of bkucine. Prepared in the same manner, and 

 as well as other salts of brucine for the same purpose ; not used 

 as yet. 



Sulphate of morphia. Dissolve morphia in oil of vitriol, 

 previously diluted with a considerable quantity of water ; evapo- 

 rate and crystallize : narcotic, a quarter of a gr. to gr. j, in a aay 

 and night. ' 



Acetate of morphia. Dissolve morphia in acetic acid q. s. 

 and evaporate to dryness ; narcotic, a quarter of a gr. to gr, j, in 

 a day and night. 



VIII. ACIDS. 



of liquid acids is usually expressed in England by 



11 of their specific gravity, water being considered 



* unity ; and in France and the neighbouring countries, by the 

 'OH of Baume's hydrometer, on account of its easy construe- 

 but this does not answer for all acids, for the experiments 

 )lcrat, a manufacturer of acetic acid, showed that the 

 th of acetic acid cannot be determined by the mere consi- 

 ration of its s|>ecific gravity ; and the case is probably the same 

 nth some other acids formed in or from organic Iwdies. 

 ( Hence the French chemists have introduced a fictitious stan- 

 ird, founded upon the capability of the acid to saturate a deter- 

 ■Alinate weight of well-crystallized subcarbonate of soda: the 



V 2 



