Rensselaer Republican, Volume 17, Number 25, Rensselaer, Jasper County, 26 February 1885 — POPULAR SCIENCE. [ARTICLE]

POPULAR SCIENCE.

> A German botanist has given instances of* the modification of plants by insects' so as to produce new varie ties. , . ;■« [ -r The number pf living specimens known in the animal kingdom is at least 300,000 of which more than nine tenths are invertebrates. Experiments in England have shown' that gas and oil are about equally'good for light-houses and that the electric light is superior to either in the fine weather but probably not so good in fogs. After much experimenting, Dr. Richardson has' found a satisfactory means of causing painless death, and has introduced into the Home for Lost Dogs, in London. The animal 3 to be killed are placed in a chamber charged with a mixture of carbonic oxide and chloroform vapor, when they tranquilly fall asleep and wake no more. From surveys of the Gulf of Mexico it appears that its area is 595,000 square-miles,- and that the area of the surface included within the line is 387,000 square miles—rather more than one-third of the surface having a depth of less than 100 fathoms. The greatest record depth in the Gulf is 2,119 fathoms, the mean’depth being >BSB fathoms. In lobsters and crabs the mouth is situated underneath the head, and consists of a soft upper lip, then a pair ol upper jaws provided With a short feeler, below which is a thin lower lip. Then follow two pair of membraneous under jaws which are jobed and hairy, and next three sair of foot jaws. The horseshoe crab has no special jaws, the thighs answering the purpose. Sir Joseph Fayrer considers it most remarkable that a poisonous snake cannot poison one, of its species, and only slightly any venomous snake, although it quickly kills harmless snakes. A,vigorous cobra can kill sevsral dogs or from a dozen to twenty fowls before its bite becomes impotent, and then the rapid re-secretion of virus soon makes it as dangerous as ever. Birds are without lips or teeth, the jaws being covered with horn forming a beak. This varies greatly in shape, being extremely wide in the whippoorwill, remarkably long in the pelican, stout in the eagle, and slender in the hummer. It is hardest in those that tear or bruise their food, and softest in water birds. The tongue is also covered with a horny sheath, its chief function being to secure the food when in the mouth. It is proportionally largest and most fleshy in the parrots. Researches in France by Dr. Schultz have shown that citric acid possesses powerful antiseptic properties, which may give it an important place as a food preserving substance, since it is believed to be free from the objection of unwholesomeness urged against other antiseptic acids. Meat fragments placed in a 5 per cent, soln; tion of the acid were in a state of perfect preservation at the end of fifteen days. Experimenting upon organized germs, Dr. Schultz found that one drop of a solut on of one part acid to 1000 of water placed in liquid containing bacteria and other germs of microscopic life Instantly caused their death.