VOL. XLI.] PHILOSOPHICAL TRANSACTIONS. 423 



water; it was easily torn, and its inner or villose metrtbrane adhered so little to 

 the others, that it was detached from them in pieces. A certain quantity of 

 this fascula, being accumulated there, retarded digestion, and those animals 

 died hectic, though with a full stomach. 



The eyes of these animals, while alive, seemed as red as those of some parrots. 

 The capsula of the crystalline, and that of the vitreous humour, were of a 

 crimson red, though neither the vitreous humour nor the crystalline were dyed. 



The tinged bones being broken, while fresh, or before drying in the air, 

 seemed somewhat larger and fuller of marrow; but also more spongy, or of a 

 looser texture, and easier to break, than the white bones of the pigeons fed 

 with meal only. The parts of these bones that had the least degree of hard- 

 ness, broke between the fingers, which remained coloured from them ; and this 

 tincture does not come from the marrow, which continues in its natural state, 

 like all the other soft parts. The same parts in the white bones were not to be 

 broken in this manner. 



On viewing these bones with a good glass, their smoothest surface appears 

 bored with a vast number of small holes, in which the colouring faecula is per- 

 ceived. And with a microscope that magnifies still more, there appears a sort 

 of net- work of fibres, which divide, and reunite, to form this net. Under 

 the first order of this net-work, which appears white, another is seen some- 

 what red, and under this a third and a fourth, still deeper coloured ; in fine, 

 the ground under all these reticular strata is of a very deep red; and the whole 

 may be justly enough compared to a piece of wood stripped of its bark. 



In other experiments, some young pigeons, fed with the paste mixed with 

 madder, died the third day ; yet all that had the consistence of bone in their 

 skeletons, was become as red as scarlet. Mr. Belchier was surprised to see the 

 bones of his cock tinged red in 1 6 days, yet here are bones so coloured in 3 days. 

 But all that should in course of time have turned to bone in one of the young 

 pigeons, and as yet was but cartilage, as the epiphyses, the great apophysis of 

 the sternum, &c. had not taken the least colour. In the other, there were some 

 spots of a very weak red on the cartilage of the sternum, which probably began 

 to ossify. Other experiments, since tried, have taught with greater certainty, 

 that the cartilages in general are not tinged red by the madder, except when 

 they begin to acquire the consistence of bone. 



It appears that the bones of animals that are still growing, are dyed better 

 and quicker than those of full- grown animals. Two turkeys had the same 

 ailments with the pullets of the first experiment, they fell into a decay like 

 those, and they were obliged to be killed in 15 days. 



Here we see young pigeons, whose bones were dyed of a fine carmine-red 



