368 SALICINEM 



and glacial acetic acid, and is coloured violet-red by alkalies. 



{Braconnot.) On warming salicin with somewhat diluted 



sulphuric acid and potassium bichromate, salicylous acid or 



salicyl-aldehydj C^ H^O^, is given off, recognizable by its 



peculiar fragrance, resembling that of meadow-sweet (iS/;/>'^a 

 ulmaria). 



Salicin when digested with emulsin or saliva, or heated to 

 80°C. with dilute sulphuric acid, assimilates 1 molecule of water, 

 and is split into glucose and salicylic alcohol or saMgenin, 

 C^H^O'^, which crystallizes in pearly tables, is easily soluble in hot 

 water, alcohol, and ether, melts at 82'^0., and sublimes at 100°O- 

 Saligenin is characterized by yielding in solution a deep-blue 

 colour with ferric chloride, and when boiled with dilute acids 

 by being converted into a resinous body, saUretin, C^H^^O^, 

 while oxidizing agents convert it into salicylous and salicylic 

 acids. Cold nitric acid, sp. gr. 1'16, oxidizes salicin, with the 

 production of helicin, C^^H^^O^, which crystallizes in white 

 needles, and is by ferments and dilute acids resolved into sugar 

 and salicylic aldehyd. If nitric acid of sp. gr. 1-09 is employed, 

 salicin yields helicoidin^ C^^H^^O^*, which may be regarded as 

 a compound of salicin and helicin. {National Dispensatory.) For 

 a full account of these interesting reactions, the reader is referred 

 to Watts' Diet, of Chemistry, YoL V., p. 147. 



Bidangubin or ' ' willow honey " has been examined by Raby 

 {Union Pharm , May, 1889, p. 201). It affords about 12 per 

 cent, of sugar, estimated as glucose, and a considerable quantity 

 of a sugar crystallizing in opaque hard crystals like those of 



sugar of milk. It melts at 150° to a transparent liquid, and 

 dissolves in 5-5 parts of water at 15° 0. The formula is given - 

 as C 'H'*0^*. This sugar evidently possesses considerable 

 affinity to^ melezitose, from which it differs, according to 

 M. Raby, in not being efflorescent, and in the greater rotatory 

 power of the glucose derived from it by inversion over that 

 obtained from melezitose. The inversion by means of dilute 

 hydrochloric acid also takes place more rapidly. He therefore 



proposes to call the uew sugar hid.ngushimm. 



