vn ihf Bo7WS of Antvials. 1 17 



history of the })hcnomcna connected with it, 

 and the purposes to which it has been applied, 

 previous to entering upon the more immediate 

 object of this paper. 



Many experiments have been made to as- 

 certain how long u time is required to produce 

 the tinge, and whether it be permanent or 

 only temporary. Belcher and Morand, about 

 •the same time, mixed madder root with the 

 food of chickens and young pigeons. The 

 result of their observations was, that the tinge 

 was more quickly communicated to the bones 

 of growing animals, than to the bones of 

 animals which had already completed their 

 growth 'y the bones of young pigeons being 

 tinged of a rose-colour in twenty-four hours^ 

 and of a deep scarlet in three days ; whilst the 

 bones of adult animals only exhibited a rose- 

 colour in fifteen days. They found the tinge 

 most intense in the solid parts of those bones^ 

 which were nearest to the centre of circula- 

 tion ; whilst in bonfes^of equal solidity, at a 

 greater distance from the heart, the tint was 

 more faint. The dye was deep in proportion 

 to the length of time the madder had been 

 continued, and when it was discontinued, 

 the colour gradually became niore ^nd nfibre 

 faint, till it entirely disappeared. According 

 .to the experii;nents of these gentlemen, othe;. 

 T 2 



