Page:Popular Science Monthly Volume 9.djvu/662

636 produced by exposure of the blood to a vacuum for many hours. A second series of experiments was to determine the influence of time on poisonous material. When the putrefied blood was kept so long that no living bodies could be discovered in it by microscopical examination, the same toxic effects were produced by its injection, but were less intense. Putrefied blood was then dried by slow exposure to the air, powdered, mixed with distilled water, and injected. The effects were not, as in the other cases, immediately manifest. After four to six days of incubation, the animals became ill; some died, others recovered. M. Feltz concludes that, as exposure to a vacuum and desiccation did not remove the toxic agent, it cannot be a gas; that activity on the part of the minute moving particles within it is not necessary for its septic effect; and that the development of bacteria, etc., in the blood of the animals injected, points to the germs of those bacteria as being the probable efficient means of the production of the poisonous effects.

Ostrich-Farming.—Ostrich-farming has within the past few years attained a remarkable development in South Africa. We present to our readers a few notes upon this new industry, taken from an address by Mr. P. L. Simmonds before the London Society of Arts. The climate in all parts of the Cape Colony is said to be alike favorable to the growth and production of the ostrich, and there are but few districts of the colony where this industry is not carried on. Mr. A. Douglas, of Hilton, appears to have been the first systematic breeder of ostriches in the Cape Colony. About eight years ago he bought a pair of birds, and subsequently added four more, making in all two cocks and four hens. By means of an incubator he succeeded in raising from these six birds 130 young ostriches in one season. The ostrich-farm of Mr. Kinnear, of West Beaufort, consists of eight acres of land, inclosed with fences. In this inclosure, which is sown with lucern, thirty ostriches are kept. There are two methods of obtaining the feathers, plucking them, and cutting them a little above the roots, which are removed two months afterward. Mr. Kinnear prefers the latter mode. The first plucking takes place when the bird is about eight months old, but the feathers are then not of much value. The operation is renewed every eight months. Three pluckings of birds in full plumage realized to Mr. Kinnear £240, or £120 per annum, that is, £8 per bird.

In the wild state, five female ostriches are often attached to one male, and they all lay their eggs in one nest, and sit on them in turn. Mr. Kinnear, however, only assigns one female to each male. They are coupled in July (the second month of winter), and commence laying in August, and continue laying for about six weeks, after which they sit till October. A month or six weeks later, they recommence to lay for about five weeks, provided the young brood are removed. In forming the nest—a large hole scraped in the sand—the male bird is most assiduous, and when all is ready the laying of the eggs commences. From fifteen to twenty eggs are laid and carefully arranged in the nest. The male bird usually sits by night, the female morning and evening; in the wild state the birds frequently leave the nest untended during the heat of the day.

Ostriches are, comparatively, inexpensive to keep, as during three-fourths of the year they require only a little artificial food, the grass produced on the farm being nearly sufficient for their maintenance; during the remaining fourth, they only need some supplemental supplies of green food, with a little Indian-corn. Each ostrich eats about twenty pounds of lucern a day.

Culture of the Cochineal Cactus.—The culture of the cochineal cactus was introduced into the Canary Islands in 1840. This plant, as indicated by its name, is the favorite food of the cochineal insect, whose body furnishes the well-known dyestuff cochineal. The culture developed rapidly, still for some years the supply of cochineal fell short of the demand. In 1848 prices varied from eleven to twelve francs per pound Spanish, the cost of production not exceeding 25 per cent, of this sum. A "cochineal mania" was the result, and all other crops had to give way before cochineal. Prices began to fall under the influence of this excessive production, and from 1860 to 1870 the cochineal sold for