INCORPORATION (from Lat. incorporare, to form into a body), in law, the embodying or formation of a legal corporation, brought about either by a general rule contained in such laws, e.g. as the Companies acts, and applicable wherever its conditions are satisfied; or by a special act of sovereign power, e.g. an incorporating statute or charter. The word is used also in the sense of uniting, e.g. a will may incorporate by reference other papers, which may be then taken as part of the will, as much as if they were set out at length in it.
INCUBATION and INCUBATORS. The subject of “incubation” (Lat. incubare, to brood; in-cumbere, to lie on), a term which, while strictly signifying the action of a hen in sitting on her eggs to hatch them, is also used in pathology for the development within the body of the germs of disease, is especially associated with the artificial means, or “incubators,” devised for hatching eggs, or for analogous purposes of an artificial foster-mother nature, or for use in bacteriological laboratories.
Life is dependent, alike for its awakening and its maintenance, upon the influence of certain physical and chemical factors, among which heat and moisture may be regarded as the chief. It is therefore obvious that any method of incubation must provide for a due degree of temperature and moisture. And this degree must be one within limits, for while all organisms are plastic and can attune themselves to a greater or less range of variation in their physical environment, there is a given degree at which the processes of life in each species proceed most favourably. It is this particular degree, which differs for different species, which must be attained, if artificial incubation is to be successfully conducted. In other words, the degree of temperature and moisture within the incubation drawer must remain uniform throughout the period of incubation if the best results are to be reached. It is not easy to attain these conditions, for there are many disturbing factors. We may therefore next consider the more important of them.
The chief causes which operate to make the temperature within the incubator drawer variable are the changes of the temperature of the outer air, fluctuations in the pressure of the gas when that is used as the source of heat, or the gradual diminution of the oxidizing power of the flame and wick when an oil lamp is substituted for gas. Also, the necessary opening of the incubator drawer, either for airing or for sprinkling the eggs with water when that is necessary, tends to reduce the temperature. But there is another equally important though less obvious source of disturbance, and this resides within the organism undergoing incubation. In the case of the chick, at about the ninth or tenth days of incubation important changes are occurring. Between this period and the fourteenth day the chick becomes relatively large and bulky, and the temporary respiratory organ, the allantois, together with its veins, increases greatly in size and extent. As a consequence, the respiratory processes are enabled to proceed with greater activity, and the chemical processes of oxidation thus enhanced necessarily largely increase the amount of heat which the chick itself produces. Thus an incubator, to be successful, must be capable of automatically adjusting itself to this heightened temperature.
The drawer of an incubator is a confined space and is usually packed as closely as possible with the contained eggs. The eggs are living structures and consequently need air. This necessitates some method of direct ventilation, and this in its turn necessarily increases the evaporation of water vapour from the surface of the egg. Unless, therefore, this evaporation is checked, the eggs will be too dry at the period—from the tenth day onwards—when moisture is more than ever an important factor. There is, according to some poultry authorities, reason to believe that the sitting hen secretes some oily substance which, becoming diffused over the surface of the egg, prevents or retards evaporation from within; presumably, this oil is permeable to oxygen. In nature, with the sitting hen, and in the “Mamal” artificial incubating establishments of the Egyptians, direct air currents do not exist, owing to the large size of the chambers, and consequently incubation can be successfully achieved without any special provision for the supply of moisture.
Artificial incubation has been known to the Egyptians and the Chinese from almost time immemorial. In Egypt, at Berme on the Delta, the trade of artificial hatching is traditionally transmitted from father to son, and is consequently confined to particular families. The secrets of the process are guarded with a religious zeal, and the individuals who practise it are held under plighted word not to divulge them. It is highly probable that the process of artificial incubation as practised by the Egyptians is not so simple as it is believed to be. But as far as the structures and processes involved have been ascertained by travellers, it appears that the “Mamal” is a brick building, consisting of four large ovens, each of such a size that several men could be contained within it. These ovens are in pairs, in each pair one oven being above the other, on each side of a long passage, into which they open by a circular aperture, just large enough for a man to obtain access to each. The eggs are placed in the middle of the floor of the oven, and in the gutters round the sides the fire is lighted. The material for this latter, according to one account, consists of camels’ dung and chopped hay, and according to another of horses’ dung. The attainment of the right degree of heat is apparently reached wholly by the skill of the persons employed. When this has been attained, they plug the entrance hole with coarse tow. On the tenth to twelfth days they cease to light the fires.
Each “Mamal” may contain from 40,000 to 80,000 eggs. There are 386 “Mamals” in the country, which are only worked for six months of the year, and produce in that time eight broods. Many more than two-thirds of the eggs put in are successfully hatched. It is estimated that 90,000,000 eggs are annually hatched by the Bermeans.
A method of incubating that appears to have been altogether overlooked in England—or at least never to have been practised—is that carried on by the Couveurs or professional hatchers in France. They make use of hen-turkeys for the purpose, and each bird can be made to sit continuously for from three to six months. The modus operandi is as follows: a dark room which is kept at a constant temperature throughout the year contains a number of boxes, just large enough to accommodate a turkey. The bottom of the box is filled with some vegetable material, bracken, hay, heather, straw or cocoa-fibres. Each box is covered in with lattice-work wire, so arranged that the freedom of the sitting bird is limited and its escape prevented. Dummy eggs, made by emptying addled ones and filling with plaster of Paris, are then placed in the nest and a bird put in. At first it endeavours to escape, but after an interval of a few days it becomes quiet, and the dummy eggs being then removed, fresh ones are inserted. As soon as the chickens are hatched, they are withdrawn and fresh eggs substituted. The hen turkeys are also used successfully as foster-mothers. Each bird can adequately cover about two dozen eggs.