ADDRESS. CI 



which has the honoui' of beiug identified with Faraday's scientific career. 

 At this Meeting a Committee was formed to carry out the object, and a sub- 

 scription list commenced. By permission of the Secretaries of this Asso- 

 ciation, an office has been opened in the reception-room, where those Mem- 

 bers of the Association who may be desirous of taking part in the movement 

 ^Yill have every facility afforded them. 



In chemistry, I do not believe that any great step has been made within 

 the last year ; but perhaps there is no science in which an earnest worker 

 is so sure of being rewarded by making some substantial acquisition to 

 our knowledge, though it may not be of the nature of one of those grand 

 discoveries which from time to time stamp their- impress on difi'erent branches 

 of science. I may be permitted to refer to one or two discoveries which are 

 exceedingly curious, and some of which may prove of considerable practical 

 importance. 



The Turaco or Plantain-eater of the Cape of Good Hope is celebrated for 

 its beautiful plumage. A portion of the wings is of a fine red colour. This 

 red colouring-matter has been investigated by Professor Church, who finds it 

 to contain nearlj- six per cent, of copper, which cannot be distinguished by 

 the ordinary tests, nor removed from the colouring-matter without destroying 

 it. The colouring-matter is in fact a natural organic compound of which 

 copper is one of the essential constituents. Traces of this metal had pre- 

 viously been found in animals, for example, in oysters, to the cost of those 

 who partook of them. But in these cases the pi'csence of the copper was 

 merely accidental ; thus oysters that lived near the mouths of streams which 

 came down from copper-mines assimilated a portion of the copper salt, with- 

 out apparently its doing them either good or harm. But in the Turaco the 

 existence of the red colouring-matter which belongs to their normal plumage 

 is dejiendent uj^on copper, which, obtained in minute quantities with the food, 

 is stored up in this strange manner in the sj^stem of the animal. Thus in 

 the very same feather, partly red and partly black, copper was- found in 

 abundance in the red parts, but none or only the merest trace in the black. 



This example warns us against taking too utilitarian a view of the plan 

 of creation. Here we have a chemical substance elaborated which is per- 

 fectly unique in its nature, and contains a metal the salts of which are ordi- 

 narily regarded as poisonous to animals ; and the sole purpose to which, so 

 far as we know, it is subservient in the animal economy is one of pure deco- 

 ration. Thus a pair of the birds which were kept in captivity lost their fine 

 red colour in the course of a few days, in consequence of washing in the 

 water which was left them to drink, the red colouring-matter, which is 

 soluble in water, being thus washed out ; but except as to the loss of their 

 beauty it does not appear that the birds were the worse for it. 



A large part of tlie calicos which are produced in this country in such enor- 

 mous quantities are sent out into the market in the printed form. Although 

 other substances are employed, the place which madder occupies among dye- 

 stuifs with the eaUco-printer is compared by Mr. Schunck to that which iron 

 occupies among metals with the engineer. It appears from the public returns 

 that upwards of 1(J,000 tons of madder are imported annually into tlie 

 United Kingdom. The colours which madder yields to mordanted cloth 

 are due to two substances, alizarine and purparine, derived from the 

 root. Of these, alizarine is deemed the more important, as producing faster 

 coloui's, and yielding finer violets. In studying the transformations of aliza- 

 rine under the action of chemical reagents, MM. Graebe and Liebermaun 

 were led to connect it with anthracene, one of the coal-tar series of bodies. 



