1273 



a. antipyretic alkaloids ; 



b. salicylic acid and its derivatives ; 



c. the other anodynes and the medicines that lower the temperature. 



Group a. The antipyretic alkaloids are on the whole sparingly 

 soluble, at the most up to yoW ^^- ^^^^ surface tension is distinctly 

 lowered by chinin, chinidin, cinchonin ; it was not demonstrable in 

 cinchonidin, chinamin, conchinamin. Volatility is undoubtedly a pro- 

 perty of cinchonin (according to sublimation test) and of chinamin 

 (in consequence of the loss of electrifying power subsequent to the 

 suction of air). The saturated aqueous solution, sprayed under an 

 overpressure of two atmospheres, distinctly electrifies a screen ar- 

 ranged in the way of the nebula at a distance of about 25 cm. 

 The sign of this charge is positive (as in the case of most odorous 

 substances) and the air round il and at some distance from it is charged 

 negatively. Though clearly noticeable, the phenomenon falls behind 

 that of the odorous substances. 



Group b. Salicylic acid and its derivatives represent a group 

 of chiefly crystalline substances, whose solubility differs much. 

 Amongst them there are two that are completely insoluble, viz. 

 salol and benzylsalicylate, and on that account have no or hardly 

 any electrifying power. Of the remaining only salicylas chinini is 

 soluble to less than -^-^-^^n, the others at least to 2.5 millinormal ; 

 some of the salts of salicylic acid are even extremely soluble in 

 water. The lowering of the surface tension is on the whole slight, 

 even absent in the case of the salts (after the trickling method); 

 only with the liquid substances of this group and with aspirin is 

 the lowering very distinct. Volatility is noticeable with salicylic acid, 

 for it sublimes (consequently also with the salts of salicylic acid for 

 they are dissociated in the dilute solutions), and also decidedly with 

 the liquid representatives of the group (judging from the boiling 

 point). 



The intensity of the electrical phenomenon they evoke, varies 

 very much. With the insoluble ones the charge, as has been said, 

 is or very near it; with the salicylic acid and the benzoic acid 

 salts it is moderate, at the least 4 scale-divisions of our electroscope; 

 with the others it is stronger, often even maximal, as with the 

 typical odorous substances (camphor, alcohol, etc.). 



The salicylic acid salts owe their electrifying power to the anion. 

 The attending cation even lessens the charge of the nebula, pro- 

 bably because it is detrimental to the surface activity of the liquid. 



