The examination of the contents of the filter, and of the filtrate, 

 is conducted according to II., Ä, b; but, besides the low acids of 

 the fat-acid series named there, other acids, as angelic, salicylous, 

 &c., acids, must not be neglected, or even the investigation of as 

 yet unknown acids. 



The discovery and estimation of (with water) non-volatile acids 

 is not effected with the liquid remaining from the distillation of 

 the volatile acids, on account of the great amount of phosphoric 

 acid contained in it; but, with the liquid c, ß of the preceding 

 (VIII.) section; whereas the acid remnant, if necessary, may be 

 employed for the investigation of volatile alkaloids (X.) 



X. — Distillation with Alkaline Water, 



For a thorough investigation of volatile alkaloids, at least 1 

 kilogram of the dried raw material is requ.ired. Similar to 

 volatile acids, their separation is efiected best by distilling the 

 aqueous extract of the respective vegetable substance with an 

 alkali, for the reason given before, and in order to prevent rising 

 of the liquid and evolution of much ammonia. The latter is 

 obtained, indeed, even in distilling the extract, because no vege- 

 table extract is free from ammonia-salts or from other nitrogenised 

 compounds, but in much less quantity. 



Exti'act the substance by a warm digestion with four to six 

 times its quantity of water (which, in presence of tannic acid, is 

 mixed with l-25th its weight hydrochloric acid of 1*12 specific 

 gravity), press, pour the whole liquid into a copper-boiler (well 

 adapted for this purpose is the boiler of the Beindorf 's apparatus) ; 

 saturate with slaked lime, add as much lime, slaked and mixed 

 with water to the finest pulp, as to eifect an excess of 50 grams 

 quick-lime to every kilogram of raw material, and distil by 

 means of a good refrigerator, until the distilling water is void or 

 nearly void of alkaline reaction. 



In case of any scarcity of raw material, the investigation of 

 volatile alkaloids may be effected by means of the acid residue 

 left from the distillation under IX., but modified in such a way as 

 to use caustic soda instead of quicklime, in order to prevent the 

 formation of insoluble phosphate of lime. 



Saturate the whole distillate exactly with diluted sulphuric acid, 

 evaporate on the water-bath, and after due concenti-ation in a 

 weighed dish under the receiver of an air-pump, until no further 

 loss of weiglit be observed. Weigh the salty remnant, triturate if 

 necessary, shake in a flask with absolute alcohol ; collect the in- 

 soluble portion (sulphate of ammonia) on a filter, wash with 

 absolute alcohol, dry by means of the air-pump, and weigh. By 

 subtracting the latter weight from that of the whole remnant, the 

 quantity of the sulphate of the alkaloid is obtained ; and by deter- 



