412 STARCHES, GLANDS, &c. 



which is changed to deep blue by sulphuric acid. It burns easily, 

 leaving less than 1 per cent, of ash. 



Constituents. Cotton wool consists principally of cellulose 

 (C 6 H 10 O 5 ) n , associated with traces of inorganic matter, albuminoids, 

 &c. The fatty matter is partly a wax soluble in alcohol and ether, 

 and melting at 86, partly a mixture (apparently) of stearic and 

 palmitic acids. 



Cotton wool is best identified by microscopic examination. It may 

 be distinguished from animal fibres by being insoluble in hot 8 per cent, 

 solution of potassium hydroxide, by not being stained permanently 

 yellow by a solution of picric acid, and by containing only traces of 

 nitrogenous substances. It differs from many other vegetable fibres 

 by the blue colour it yields with iodine and sulphuric acid, but its 

 ultimate identification can be effected only by the microscope. 



Allied Drug. Cibotium or Penghwar Djanibi is a brownish woolly 

 substance consisting of the hairs from the bases of the fronds of 

 Cibotium Barometz, Link, O. glaucum, Hooker and Arnold, Alsophila 

 lurida, BL, &c. (N.O. Filicinece), Java, Sumatra, &c. ; it is used as a 

 haemostatic (Pili haemostatic!) . 



GALLS 



(Qalla) 



Source, &c. Galls are excrescences on the twigs of Quercus 

 infectoria, Olivier (N.O. Cupuliferce), resulting from the deposition 

 of the eggs of Gynips gallce tinclorice, Olivier. 



Under the generic term of galls a large variety of excrescences and 

 other abnormal formations are included, that are produced not only 

 upon plants, but also in a few instances upon animals, the exciting 

 cause being either a plant or an animal. The plants that induce the 

 formation of galls are exclusively fungi, but a variety of animals are 

 capable of producing them, the principal being species of Cynips and 

 Aphis. Thus the true oak-apple, the bedeguar of the rose, the oak 

 gall, oak spangles, &c., are all varieties of galls produced by various 

 insects. 



The official drug is a particular variety of gall produced by a par- 

 ticular insect upon a particular plant. This variety of gall is known 

 commercially as ' Aleppo ' galls or * Turkey ' galls ; they are collected 

 in Asiatic Turkey, especially in the province of Aleppo. 



The wasp that produces these galls is Cynips gallce tinctorice, Olivier. 

 Of this insect the female only is known, reproduction taking place 

 parthenogenetically. By means of her ovipositor the wasp deposits 

 an egg between the rudimentary leaves near the growing-point of 



