BY JOSEPH LAUTEREK, M.D. 89 



by Eucabjptus corymbom, the bloodwood of the tmiber-getters. 

 If dipsolved in water it gets a still higher red colour, when some 

 strong acid is added. It also more readily dissolves in sour 

 media. By addition of some diluted liquor ammonise or other 

 basic media, the red colour at once turns into a dark brown. 

 The tingeing substance is a derivate of the tannic acid. Pure 

 tannic acid, when moistened with old oxidised oil of eucalypt, 

 at once gets a red colour, similar to the red gum of bloodwood. 

 Many other species of Eucalypts yield a brownish gum in larger 

 quantities. Nearly all of them contain some bitter extract, 

 which gives to their watery solutions a very bad taste. (Eiicalyp- 

 tics Jiemphloia, Eucdlyptua saliyna). The gum of Eucalyptus micro- 

 corys contains an acid principle similar to that of Eucalyptus 

 maculata, and is therefore useless for medical purposes. A very 

 good gum, nearly free from bitter and sour ingredients, is 

 yielded by Anyophora lanceolata. Its watery solution is of a 

 brownish yellow, changed by the addition of alkalies into a 

 darker colour. It is very rich in tannic acid, and the same can 

 be said of the fresh bark, which certainly would be much better 

 for tanning purposes than the bark of the acacias. 



