Science.

Waikato Times, Volume XIX, Issue 1568, 22 July 1882, Page 6

Science.

Recent Extinction op tije Mastodon. The existence of the mastodon in North America must have been move recent than commonly supposed. A number of new facts bearing on this subject are to be found in Professor John Colletts " Goelogical Report of Indiana for 1880," recently issued. Of the thirty individual specimens of the remains of the mastodon {Mastodon f/i(/a>itctt&) found in Indiana, in almost overy case a very considerable part of the skeleton of each animal proved to be in a greater or less state of decay. The remains have always been discovered in marshes, ponds, or other miry places, indicating at once the cause of the death of the animal and the reason of the preservation of the bones from decuy. Spots of ground in this condition are found at the summit of the glacial drift or in " old beds " of rivers which have adopted a shorter route and lower level ; consequently, their date does not reach beyond the most recent changes of the earth's surface. In fact, their existence was so late that the only query is, says Piofcs&or Collett : Why did they become extinct ? A skeleton was discovered in excavating the bed of the canal a few miles north of Covington, Fountain county, in wet peat. The teeth are in good preservation, and Mr Perrin Kent states that when the larger bones were cut open the marrow, still preserved, was utilized by the bog-cutters to "grease " their boots, and that pieces of sperm-like substance two and a-half inches to three inches in diameter (adipocere) occupied the place of the kidney fat of the monster. During the summer of ISSO an almost complete skeleton of a mastodon was found six miles north-west from Hoopston, Iroqiiois county, Illinois, which goes far to settle definitely that it was not only a recent animal, but that it survived until the life and vegetation of to-day pievailcd. The tusks foimcd each a full quaiter of a circle, were nine feet long, twenty-two inches in circumference at the base, and in their water-soaked condition weighed one hundred and seventy-five pounds. The lower jaw was well preserved, ■with a full set of magnificent teeth, as usual, were thickly enameled, and weighed each from four to five pounds. The legbones, when joined at the knee, made a total length of five and a-half feet, indicating that the animal was not less than eleven feet high, and from fifteen to sixteen feet fiom biow to rump. On inspecting the remains closely, a mass of fibrous, bark-like material was found between the ribs, filling the place of the niiimal'sstonizich When carefully separated it proved to be a crushed mass of herbs and grasses, similar to those which still grow in the vicinity. Iv the same bed of miry clay a multitude of small resh. water and land shells were observe d and collected. These were : 1 LMsidum, clo&oly resembling P. uhihtum Ualdeman ; 2, Vtdvata Incunnuta Nay ; 3, Yalvata, resembling- Y. striata ; 4, Planorbit, parnts Say. These mollusks prevail all over the States of Illinois, Indiana and parts of Michigan, and sho\y conclusively that, however other conditions may differ, the animal and vegetable life, and consequently climate, are the same now as when this mastodon sank in his grave of mire and clay.

ELECTRIC LIC7IT (iOOD FOB TJIE K\ES. According to <a writer in the Scientific American, when electric light first began to bo used in our shops, factories, and places of amusoraent, it was confidentlyasserted by its opponents that so dazzling a light must bo injurious to the eye. It appears, however, from the experiments recently made by Professor Cohn, of Breslau. whose name is so familiar in connection with the investigation of color-blind-ness and other optical defects, that our eyes will bo benefited rather than hurt by the new method of lighting, and it is obvious that with incandescent electric lighting the advantages will be still more marked. While testing 1 the influence of electric light on visual perception and the sense of color, Dr Cohn proved, he thinks, that letters, spots, and colors wero perceived at a much greater distance under electric illumination than by gas-light, or even daylight. Compared with daylight, the electric light increased the sensation of yellow sixtyfold, red sixfold, and green and blue about twofold. In all cases of disttmt signaling, Dr. Colin bolievos that the electric light will prove exceedingly and especially useful.