8ALTCTNEM. 367 



add, when it was again experimented with by Ringer and 

 Bury, wlio sliowed that it had no influence upon the tempera- 

 ture of healthy children. They observed that under full 

 medicinal doses a dusky flush suffuses the face on slight 

 excitement, while the expression becomes dull and heavy. 

 Less constant symptoms are deafness^ noises in the ears, frontal 

 headache, trembling of the hands and quickened breathing, 

 Yery large doses occasion severe headache, marked muscular 

 weakness, tremor and irritability, with a rapid and feeble pulse. 



Description., — Catkins 1 — 2 inches long^ thick, cylin- 

 drical, bright yellow, fragrant; bracts oblong, small; scales 

 obovate, blackish, hairy ; nectary ovate, papillary ; stamens 

 longer than the scales, with oblong yellow anthers ; germ ovate- 

 lanceolate, silky, on a hairy stalk; style hardly any; stigma 

 oblong, thick^ undivided. Bark purplish-brown externally, 

 minutely downy when young, internally white ; tough and 

 fibi'ous. 



Chemical composition. — Willow bark has been shown to con- 

 tain salicin, wax, fat, gum, and a tannin which gives with 

 ferric salts a blue-black precipitate, the liquid becoming pur- 

 plish-red on the addition of soda. Johanson (1875) has also 

 shown the presence of a kind of sugar having a slightly sweet 

 taste and reducing alkaline copper solution with difficulty, and 

 of the glucoslde benzohelicin, C-"H-^0^, Salicin, a glucoside, 

 crystallizes in colourless plates or flat rhombic prisms, but it 

 usually occurs in commerce in white glossy scales or needles. 

 It remains unaltered in the air, is neutral to test-paper, in- 



^ 



odorous, and has a persistently bitter taste. It is soluble in about 



30 parts of water at 11'5° C, and is somewhat less soluble in 

 alcohol. It dissolves in 0'7 part of boiling water and in 

 2 parts of boiling alcohol. (United States Pharm ) Cold sul- 

 phuric acid dissolves salicin with a bright red colour ; after the 

 absorption of water from the air (but not after the addition of 

 water or after being neutralized by an alkali), the solution 

 deposits a red powder {rutilin), which after washing is yellowish- 

 red, after drying blackish-brown, insoluble in water, alcohol^ 



