2o8 



THE BOOK OF POULTRY. 



the copper districts, and that in captivity the 

 birds prefer, and constantly mouth and peck 

 at, brass rails. Yet these strong metallic 

 colours are strictly localised, no colour, or any 

 copper, being found in adjacent parts of the 

 very same feather. Also in some species of 

 Turaco which have none of this colour, the 

 same patches, instead of being crimson, are 

 white ; where for some reason this colour fails 

 to deposit, there is no colour at all ! From 

 many other birds, various colours have been 

 extracted by Mr. Church and others, by such 

 solvents as alcohol, ether and alkaline solution. 



The Brazilians have an extraordinary method 

 of modifying the colour of certain parrots, 

 which are naturally green about the head. 

 When these feathers are just showing, they 

 apply to them tlie secretion from the skin of a 

 certain native toad, with the result that the 

 feathers then become, not green, but bright 

 yellow ! This is no exhibition matter ; simply 

 a custom or fashion the people have. The result 

 and the process are alike extraordinary', and 

 still more, perhaps, how it can have been dis- 

 covered in the first place. Here we perhaps 

 have an e.xample of colour-feeding individual 

 feathers, for it certainly is not a dye in any 

 ordinary sense, only affecting the growing 

 plumage. 



The most interesting results, as ascertained 

 by direct scientific experiment, were communi- 

 cated by Dr. Sauermann to the Vienna Ornitho- 

 logical Association.* He ascertained definitely 

 in regard to cayenne, that the piperine or hot 

 ingredient of hot peppers had no part in the 

 result ; that the coloured component given pure 

 had also very little effect; and that it was only 

 efficacious when given in chemical combination 

 with albumen or fat. Feeding cayenne to 

 twelve white Leghorns, two only of the birds 

 showed results, these two beginning to do so 

 after ten days. In their case the plumage was 

 turned red, but chiefly in two places only, the 

 breast and the hackles, the body much less so, 

 and the flights and tail remaining white to the 

 last. The colour only appeared on the surface, 

 where exposed to the light. The second season 

 or moult the same birds were cayenne-fed again, 

 but now became a duller reddish brown in the 

 coloured portions. The legs and feet were also 

 coloured orange red. The yolks of the eggs also 

 became red, in some cases bright blood red. 

 Such yolks could not be boiled hard, the soluble 

 fat being increased at the expense of the solids. 

 All the fatty parts revealed the presence of 

 colouring matter. On hatching the eggs, the 



* Dit Schwalhe, April 30 .md May 15, 1S90. An English 

 translation appeared some time after in the Feathered World. 



chickens showed no colour in the down, but 

 were decidedly red in the first feathers, which, 

 however, soon faded unless they were themselves 

 fed on cayenne. It was remarkable that while 

 only two out of the twelve pullets origin- 

 ally fed were able to absorb the colour, all 

 the chickens hatched from these two coloured 

 birds inherited the tendency. 



A series of experiments were then made 

 upon canaries with aniline dj'es, which it was 

 found were rarely poisonous when pure. Given 

 in water, a few birds only were slightly affected, 

 and the effect lasted only during the growth of 

 the feathers. By rather difficult processes the 

 dyes were then combined chemically with oil, 

 but little result was obtained in the way of 

 colour, owing (as was afterwards found) to excess 

 of the colour feed. But a most extraordinary- 

 result was established in the way of direct 

 connection between colour feed and moulting 

 itself, which may possibly prove of use in regard 

 to the latter, and which Dr. Sauermann thought 

 probably due to the soluble fats combined with 

 the colour. The canaries fed with coloured oils 

 did not moult. Whenever the feed was stopped, 

 moult continued; when resumed, they " stuck " 

 again. Similarly, by feeding cayenne in larger 

 quantities to fowls, their moult also was post- 

 poned till the end of December. These facts 

 probably explain why some insectivorous birds 

 cannot moult in captivity. On the contrary 

 side, one colour was found — gentian violet — 

 which had the property of inducing moult at 

 any time, even quite out of the ordinary course. 



Finally a few of the dyes were combined 

 with albumen, and in this form, and given more- 

 sparingly, striking results were obtained. At 

 first the dyes were boiled with grain, with whose 

 albumen they then combine ; but it was found 

 sufficient to mix them in ordinary bread before- 

 baking the latter. The dyes thus treated lose 

 their bitter taste, and crumbs are eaten freely. 

 Only two dyes are reported on in the paper. 

 By feeding fawn-coloured Isabel pigeons with 

 methyl-eosin (known to chemists as methyl- 

 tetrabromofluorescein) the colour was changed 

 to red, and was fast. By feeding Budgerigar.s- 

 with methyl-violet (chemically a combination of 

 the hydrochlorides of pentamethylpararosaniline 

 and hexamethylpararosaniline), they became 

 blue. These blue Budgerigars are the most 

 striking result yet produced in bird culture, and 

 in their case the dye was combined with millet, 

 or baked with egg-bread to be given to the 

 young. Only 30 per cent, of the birds experi- 

 mented with were affected, whilst of white fowls 

 fed with cayenne only 20 per cent, responded. 

 It will be remembered that amongjst canaries 



