KIDD'S LONDON JOURNAL. 



247 



we have just described, as forming so interesting 

 a feature in autumnal evening walks, have long 

 ago ceased; and it is now a rare thing to see a 

 passing flock of even fifty, where, in years gone 

 by, they mustered in myriads. 



ON ARTIFICIAL INCUBATION. 



By Dr. J. Lotsky. 



Artificial Incubation of the eggs of 

 domestic volatiles, although Avell known to 

 the people of the East, may, by its recent 

 introduction in Europe, filially realise that 

 philanthropic wish of Henry IV. of France, 

 " that every laborer should have a fowl in 

 his pot, at least on Sunday." At any rate 

 the introduction of poultry in the dietary 

 of hospitals, &c. will be matter of great uti- 

 lity. At the present time already, this pro- 

 cedure has been utilised in Vienna, where 

 several tavern-keepers have entered into con • 

 tracts for the constant supply of poultry ob- 

 tained by artificial hatching. 



This process might however be also 

 made available for the purposes of science, 

 of which, more hereafter. The hatching of 

 tropical birds would not only afford to the 

 Public sights novel and interesting, but be 

 made the means of many an observation on 

 the habits {psychology) of these animals, the 

 comparative anatomy of their embryo, &c. 

 But the tropics have now been removed to 

 a very short distance from these shores ; 

 indeed eggs from Jamaica, Cuba, &c, 

 may arrive here in about three weeks, and 

 even sooner. As the eggs of farm yards pre- 

 serve their incubability thus long without 

 any especial precaution, those imported from 

 abroad might also retain vitality for a simi- 

 lar space of time. But there exist several 

 modes of preserving eggs fresh during a 

 whole winter — painting them with fat, placing 

 them amongst sawdust, &c, which might be 

 experimented upon for the present emer- 

 gency. 



Little doubt exists in my mind, that the 

 larger eggs of the Anserine, Passerine, and 

 even Psittacine tribes could be hatched in 

 this way. But the finest, because hitherto 

 unseen sight — the humming birds would ex- 

 hibit. Without alluding first to the smaller 

 species, some of whose eggs are not larger 

 than peas, I have seen some in the Brazils, 

 whose body approached the size of a gold- 

 finch, &c. If such be once hatched, the 

 difficulty of feeding them might be over- 

 come by dipping a camel-hair brush into 

 honey, or making, for the more grown up, 

 some artificial corollas of flowers with a re- 

 ceptacle of honey at the bottom, &c. In 

 fact, some trouble might be cheerfully be- 

 stowed on seeing humming birds in the 

 Megenfs Park, alive. 



A variety of reflections attaches itself to 

 the popularisation of artificial incubation, 

 affording occasion for many experiments 

 hitherto neglected. We know that a hen will 

 hatch ducks, which she cannot follow in 

 their favorite element ; but will an Anserine 

 female ever hatch Gallinaceous birds — where 

 she would have to forsake altogether her ac- 

 customed element? In fine, is the time of 

 incubation for a certain species of eggs the 

 same whether they be hatched by a hen of 

 their own species, or by one of even another 

 genus or family, or in the artificial oven ? 

 Has it ever been tried to hatch Accipitrina) 

 or Falcos by Gallinaceous Females ? The 

 vital, generative process of the incubation of 

 an egg, is one of the most mysterious within 

 the whole range of our observation ; because 

 an incubated egg is a thing unconnected with 

 the [external) world around it ; there is no 

 umbilicus, no placenta, not even a uterus — 

 all which the egg contains within its own 

 compass. It is yet also an unsolved question, 

 whether the interior of the egg communi- 

 cates (can communicate) With the atmo- 

 sphere around, as the internal epidermis of 

 the egg is a substance very densely woven 

 and apparently impermeable to the air. 

 What would be the phenomena, if an egg- 

 were placed under the bell of an air-pump ? 

 Would such egg have lost its incubatory 

 power ? I think so — because the pores of 

 the egg shell hint at some hidden cause and 

 process. 



'• But I have been wandering away —led by 

 the idea, that remote antiquity truly sym- 

 bolised creation and the 'universe under the 

 image of an egg. It exhibits, surely, the 

 only vital crystallisation of the kind within 

 the whole range of the globe's nature — far 

 surpassing the coarse and tangible nourish- 

 ment of the foetus of the Mammalia. The 

 accurate analysis of eggs in their fresh 

 state—and then during the different stages of 

 incubation, would solve many enigmas of or- 

 ganic (vital) chemistry ; because it has surely 

 not been explained hitherto, how of such 

 apparently homogeneous substances as the 

 yolk and white of the egg, successively bone 

 and cartilages and horny substances and 

 blood can arise; implying the successive 

 apparition of substances, e. g. iron, phos- 

 phor, &c, which are hardly to be supposed 

 to have existed in the primitive egg. If such 

 transformation of chemical principles should 

 take place, as I do not doubt it does — for 

 instance an avparition of iron, or even an 

 increase thereof, it would show that, besides 

 the exchanges, solutions, and precipitations 

 of our chemistry, the vital process possesses 

 a generative and creative power of changing 

 one chemical substance into another — not 

 attainable in our crucibles ! 



However all this may be still incubation 



