QUININE 689 



QUICKSILVER. Imported in 1874, 2,988,447 Ibs. ; value 841,208. See 

 MEKCTJHY. 



QT7IXi!i. See FEATHERS. 



QUINIDINE is one of the alkaloids obtained from the cinchona barks, and is 

 found in most of them. The quantity, however, varies with the quality of the bark ; 

 Cinchona Calisaya, or yellow bark, which is the most prized, containing quinine, with 

 but little, if any, quinidine, while some of the Loxa barks contain quinidine, and some 

 cinchonine, and little or no quinine ; such are the H.O. Crown barks. 



Quinidine was discovered in 1833 by MM. Henry and Delandre. It has the same 

 composition as quinine, C 40 H 24 N 2 4 (C^H 24 !* 2 2 ), but is nevertheless a distinct 

 alkaloid. 



It is obtained from the barks containing it in the same manner as quinine from the 

 quinine-yielding barks ; and owing to the employment of the inferior barks in the 

 manufacture of this latter alkaloid or its sulphate, some quinidine is always present 

 in it, but from the greater solubility of the salts of quinidine, they principally remain 

 in the mother-liquors, from which the sulphate of quinine has crystallised. 



QUININE. This alkaloid is found, together with four other alkaloids, in the 

 cinchona barks, of which there are numerous varieties, some containing principally 

 quinine, as the Calisaya or yellow bark, which is the most valuable of all the barks 

 on that account; others containing principally quinidine and cinchonine, with but 

 little quinine. 



Quinine is the principal of these alkaloids, and is now manufactured on a very 

 large scale for medicinal purposes, it being a valuable tonic and febrifuge. 



It was usually prepared from the C. Calisaya, but, owing to the scarcity and high 

 price of this bark, several of thfc inferior barks have been employed in its manu- 

 facture, and on that account the quinine of commerce frequently contains some of the 

 other alkaloids. The sulphate is the only salt of quinine which is manufactured for 

 commercial purposes, and is generally known, though improperly, as ' Disulphate of 

 quinine.' 



The following is the process most generally followed in the manufacture of this 

 salt : The coarsely-powdered bark is digested with hot dilute sulphuric or hydro- 

 chloric acid for one or two hours; the liquor is strained off, and the bark treated 

 with a fresh portion of still more dilute acid for the same time. This process may be 

 repeated a third time, but the liquor then obtained, containing so little quinine, is 

 used for a fresh portion of bark. The liquors from the first and second digestions are 

 strained and mixed, and are then mixed with lime, magnesia, or carbonate of soda, 

 until the liquid acquires a slight alkaline reaction, which may be known by its 

 turning red litmus-paper blue. Owing to the solubility of quinine, to a certain 

 extent, in milk of lime and chloride of calcium, carbonate of soda is the best to be 

 used for this purpose. A precipitate is formed, which is separated from the super- 

 natant liquid by straining through a cloth. This dark-coloured mass, which contains 

 the alkaloids, colouring-matter, some lime, and some sulphate of lime, these latter, of 

 course, only when both lime and sulphuric acid have been used in the process, is 

 treated with boiling ordinary alcohol, which dissolves the alkaloids and colouring- 

 matter. This solution is filtered, and the greater part of the alcohol removed by 

 distillation, when a brown viscid mass remains ; this is treated with dilute sulphuric 

 acid, till the solution remains slightly acid ; this solution is then digested with animal- 

 charcoal, filtered, evaporated, and allowed to cool, when the sulphate of quinine 

 crystallises out, together with some sulphate of quinidine or cinchouine, according to 

 the barks which have been employed ; but, owing to the greater solubility of these 

 latter salts than the sulphate of quinine, they principally' remain in the mother- 

 liquors. When pure animal-charcoal has not been used, the sulphate of quinine is 

 likely to be contaminated with some sulphate of lime, formed by the action of the 

 sulphuric acid on the lime in the animal-charcoal; and in this process also some 

 quinine is likely to be precipitated by the lime and lost in the animal-charcoal. 



In order to separate the sulphate of quinine thus obtained from the sulphates of 

 qiiinidine and cinchonine, advantage is taken of the greater solubility of the two 

 latter salts, as above mentioned, and by several crystallisations the sulphate of quinine 

 may be obtained nearly free from these salts. The quantity of sulphate of quinine 

 obtained from each pound of bark of course varies with the bark used. Some of the 

 best Calisaya bark will yield half an ounce of the sulphate from every pound of bark, 

 while many other barks which are used in the manufacture of sulphate of quinine 

 do not yield a quarter of an ounce. 



A process has been patented by Mr. Edward Herring for the manufacture of 

 sulphate of quinine without the use of alcohol, and it yields the article known as 

 'hospitalsulphate of quinine' at the first crystallisation and without the use of animal- 

 charcoal.. The following is the outline of the -process : 

 VOL. III. Y Y 



