316 Scientific Intelligence. [Oct. 



dissipated in vapour. It is, therefore, advisable to procure hops recently 

 picked, at the present season of the year (before they are placed on the 

 kiln), when, by distillation from ten pounds (with ten gallons of 

 water) placing in the receiver or separator, a saturated solution of alum, 

 the essential oil will saturate. I am, Sir, 



Your obedient servant, 



J. T. S. 



II. Process Jar extracting Cinchonin from Cinchona. 



The following process is given by M. Badolier (Ann. de Chimie et 

 de Physique, torn. xvii. p. 273) : A pound of yellow bark, bruised, is to 

 be boiled in three pints of a very dilute solution of caustic potash (eau 

 alcalise par la potasse caustique). After the ebullition has continued 

 for a quarter of an hour, the liquor is to be suffered to cool, and strained 

 through a fine cloth with pressure ; the residuum is to be repeatedly 

 washed and pressed. 



The cinchona thus washed is to be slightly heated in a sufficient 

 quantity of water, adding gradually muriatic acid until litmus paper is 

 slightly reddened, and stirring the mixture. When the liquor is near 

 the boiling point, it is to be strained, and the cinchona strongly pressed ; 

 then add to the strained liquor while it is hot, an ounce of sulphate of 

 magnesia ; after this, precipitate the whole with caustic potash, slightly 

 in excess. When the liquor is cold, the precipitate is to be collected 

 on a filter, washed, and dried, and then treated with alcohol, as directed 

 by MM. Pelletier and Caventou, in order to obtain the cinchonin. 



When sulphuric acid is added to the cinchonin immediately after the 

 separation of the alcohol, crystals of sulphate of cinchonin are obtained, 

 which, when washed with a little water, are of a very fine white colour. 



III. Analysis qftlie Sulphates of Cinchonin. 



M. Robiquet has analyzed three sulphates of cinchonin in the fol- 

 lowing manner, and with the annexed results. Equal quantities of 

 each of the sulphates, which had been dried by the heat of a salt water 

 bath, were dissolved in distilled water ; and to each solution similar 

 quantities of pure caustic potash are added. This decomposition 

 effected with heat is attended with some peculiar characters. The 

 solution becomes at first milky; and afterwards small oily drops swim 

 on its surface ; at last, when the heat has been long continued, the cin- 

 chonin coagulates, and unites into large white masses, which are opaque 

 and very porous, and when these occur, the decomposition is complete. 

 In order to finish the analysis, it remains only to filter the liquor, to 

 separate it from the cinchonin, to wash the filter in the common man- 

 ner, to supersaturate it with nitric acid, and to add a small quantity of 

 nitrate of bary tes. 



The sulphate of barytes thus obtained indicates, of course, that of 

 the sulphuric acid contained in the salt under examination. 



By this process, M. Itobiquet analyzed the acidulous sulphate of the 

 third crystallization, subsulphate of the first crystallization, and subsul- 

 phate of the third. The cinchonin, separated from the acid, did not 

 contain any portion of sulphuric acid. 



100 acidulous sulphate of cinchonin, third crystallization : 



