424 PHILOSOPHICAL TRANSACTIONS. [aNNO 1740. 



in 3 days, which is nearly the time they must have for acquiring this degree of 

 tincture. By other experiments on young pigeons of the same age, in 36 

 hours their bones were of a lively rose-colour, and in 24 hours they were at 

 least of a flesh-colour. 



These last experiments prove with what expedition the distribution of the 

 nutritious juice is performed in animals of this kind, which acquire all their 

 growth in a few months; and how rapid the distribution is, even in those parts 

 where the blood's circulation meets with the greatest obstacle, as in the sub- 

 stance of the bones. 



The rubia probably is not the only vegetable substance that can change the 

 colour of the bones; and yet the log-wood, the anchusa and curcuma, have 

 been tried without success. Probably it must be a substance less susceptible of 

 alteration; and it is well known, tliat the rubia is of that sort, seeing that 

 clothes dyed with this root bear very well the action of the air, and of boiling. 



M. du H. put the coloured bones of the animals to several proofs; first, as 

 Mr. Belchier, to that of boiling water, and of spirit of wine, without the least 

 change of colour. It also resisted soap-suds. A strong lixivium of salt of 

 tartar discharged a little of the colour, and made it look brighter. Vinegar 

 made it take a yellowish brown and obscure tinge. In fine, alum-water dis- 

 charged the colour pretty considerably, and the water remained somewhat 

 vinous. Thus these bones perfectly well resist the same boilings as the clothes 

 dyed with the same root; but the air acts on them much sooner than on these 

 clothes; for the bones of the pullets in the first experiment, those of the turkeys 

 in a third, and those of the young pigeons, that had eaten of the madder but 3 

 days, became entirely white in less than a year, and the reddest bones lost much 

 of their colour. And he thinks, that the dew, to which he exposed some of 

 them for a few days, will finish the blanching of them. 



yi Catalogue of fifty Plants from Chelsea Garden, presented to the Royal Society 

 by the Company of Apothecaries, for the Year 1739, pursuant to the Direc- 

 tion of Sir Hans Sloane, Bart. By Isaac Rand, F. R. S. N" 457, p- 406. 



This is the 18th presentation of this kind, completing the number of 900 

 different kinds of plants. 



A Physico-mathematical Demonstration of the Impossibility and Insufficiency of 

 Vortices. By M. de Sigorgne. N° 457, p- ^OQ. 



M. de S. here takes great pains to refute the existence, and even the possi- 

 bility of the Cartesian vortices. He undertakes to prove, 1 . That the mecha- 



