EFFECTS OF COLOUR FEEDING. 



207 



animals ; for there is such a law traceable. If 

 we heat a coloured oxide, we are expanding it 

 and also, as a scientific man calls it, " adding 

 energy" to it; and even in this 

 Laws of simple case, the usual result is to 



Animal change its colour towards a tint 



Colouration, nearer what a physicist terms "the 

 red end of the spectrum," in order 

 of the rainbow colours. Heating a globule of 

 copper borate, which is blue, it turns green ; if 

 we heat the yellow oxide of mercury, it gradually 

 turns orange, red, brown, and finally almost black. 

 Now, very curiously, it seems as if a general rule 

 can be traced by which animal colours also, 

 starting from the highest degree of vitality or 

 energy, as we diminish this tend to change in 

 the converse order of black (the highest), brown, 

 red, orange, green, blue, white ; this law explain- 

 ing most changes as an infant gains strength, 

 and again declines in energy with old age, or 

 from privation. Various monkeys, e.g. in in- 

 fancy are greyish yellow, then reddish brown, 

 and finally black. Children's hair generally 

 changes from very light or yellow to red or 

 brown or black ; while with age comes grey and 

 white. At the wreck of the Stratluiiorc it was 

 observed that not only did ordinary colours 

 become grey and flaxen, but black hair became 

 for a time red and brown. Thus it seems as if 

 •richer colour may be probably the effect of 

 either more vitality or heat of blood. Eastern 

 breeds lay brown eggs, and the early native 

 Cochins were darker, more cinnamon, than the 

 ■colour became in our colder clime. Canaries 

 were green ; our rooms and more stimulating 

 food made them yellow; fed on still more 

 stimulating food, we have seen that many 

 become orange-red. Budgerigars are similarly 

 changing from green to yellow. Cayenne was 

 probably first given to canaries as a beneficial 

 stimulant, just as iron in various forms was long 

 ago prescribed by us for fowls ; and it is possible 

 that the main colour effect of these things may 

 be a t07iic effect. As to special ingredients and 

 effects, we remember personally the time when 

 the use of linseed for gloss, as described in our 

 next chapter, was a jealously guarded secret, 

 which we first made public : where is the differ- 

 ence between this, for one special end, and 

 heating tonics for another? 



Colour feeding for enriching buffs, if carried 

 on at all, must be so from the first beginning of 

 the growth of the plumage to the very end of 

 that growth, whether in chickens or moulting 

 adults. The regimen usually recommended is 

 half a teaspoonful of cayenne, of which the 

 cool kind is just as good as the hot, given 

 every day in the soft food, along with about 



two grains carbonate or three grains saccha- 

 rated carbonate of iron. A little fat should 

 be mixed also along with the cayenne. Merely 



for enriching bays and crimsons^ 



Colour Feeding ^^^ '" ^ Partridge Cochin cockerel, 



for there can be nothing gained by 



Buff Fowls. anything more than saccharated 



carbonate of iron ; plain carbonate 

 is cheaper, but saccharated is more readily as- 

 similated by the animal system. On the other 

 hand, there is some reason to think that iron may 

 be occasionally injurious to a buff bird, in accen- 

 tuating the slightest difference of colour. While 

 a uniform colour would probably be slightly 

 deepened in tone, any deeper patches, or the 

 slightest tendency to black specks, would prob- 

 ably be brought into stronger relief by iron, while 

 cayenne would be less likely to have this effect. 

 One or two people have recommended the 

 "yellow " cayenne or colour feed sold to canary 

 breeders ; and we have also seen Silk's and 

 Sandiford's canary feeds recommended. We 

 repeat, however, that if by careful breeding an 

 even and rich buff has been produced, there is 

 not the slightest reason to believe it will ever be 

 surpassed by colour feeding : the sole question 

 is as to how nearly inferior colour may be made 

 to equal or approach it. 



As a field for experinicnt, colour feeding is 

 a tempting one, on which account we should be 

 sorry to see it barred, though we do not antici- 

 pate much direct result from it. The principal 

 facts known up to the present may be worth 

 summarising, and are full of interest. There is 

 a family of African birds known as Turacos or 



Plantain-Eaters, containing twenty- 

 Remarkable five species, of which eighteen 

 Facts manifest the following extraordin- 



Conceming ary phenomena. On certain wing 

 Colour in Birds, r .\ „f j i • 1 .. j 



leathers, of dark violet ground 



colour, are patches and spots of 

 bright crimson ; also in some, on a few head 

 feathers. This crimson soaks out into cold 

 water, and birds kept in captivity wash out 

 these patches to a dirty white in their bath, 

 while the wild ones become a dirty grey or very 

 pale pink in the rainy season ! In dilute am- 

 monia it dissolves easily. Analysis shows this 

 colour to contain 7 per cent, of its weight, when 

 precipitated from ammonia solution, of pure 

 copper, probably deposited from bananas, in 

 which copper is found, and on which the birds 

 feed. So full of copper is it that a red piece of 

 feather burnt gives a green flame. Copper is 

 also found in a green pigment got from the same 

 family ; and Mr. Lupton has found copper in 

 the feathers of some Australian green parrakeets. 

 It is remarkable that these latter are found in 



