SCIENCE NOTES.

Otago Witness, Issue 3114, 19 November 1913, Page 68

SCIENCE NOTES.

Substitute for Marble. — A German inventor lias succeeded in producing a substitute for marble of all classes, including the most highly prized Italian, Egyptian, and Salzburg marbles, which he claims is superior to other marbles in being stronger and loss' liable to crack or damage. Artificial Daylight.— Dr Herbert E. Ives claims to have invented daylight. Scientific men have worked for years trying to accomplish this task Dr Ives has been at work for at least a dozen years, and he asserts ho has finally produced a light which is in every way equal to sunshine. The scientist has designed a powerful incandescent lamp with a special mantle, which is so placed in a cabinet he has designed that its rays are immediately beneath a reflector. This is made of metal, and the light is forced downward through a series of delicatelycoloured screens, so arranged that the average rays which are not found in the north light are eliminated, and the effect, it is said, is that of a perfect harmony of light similar in every way to the rays of the sun. Two Hundred Miles an Hour.—

Mr Henry Ford, tho famous motor car manufacturer, expresses the opinion that there is no reason why motor cars should not eventually attain 150 or 200 miles an hour; but he says they would require special highways In fact, rails would probably be the proper thing, just as we have rails now for railway trains. “Lightness/ he says, 1 is what wo are striving for, more than any other thing. It won’t bo long before the present 13001 b motor car will bo reduced in weight to 5001 b. This will mean great speed, and a somewhat lower price ; but the price cannot bo greatly decreased, because tho lighter material demands greater strength and craftsmanship. —ls Tea Injurious?

The tannin in tea is generally considered as the source of mischief in excessive teadrinking, but it is not generally known that there is more tannin in claret than in tea, and that whereas in wines it is in the free active state, m tea it is neutral or fixed and incapable of acting as a tanning agent. Hence lea-drinkers can view with complacency loose theories propounded merely for party purposes, and without much thought of their being taken seriously. "Excessive” tea-drinking is an ambiguous term ; but wo know of one man who does even a fuller year’s work between January and December than falls to the lot of Mr Lloyd George as Chancellor of the Exchequer, and yet seldom drinks anything between his breakfast and tea, when the quantity of tea he consumes has at times amused many people. Black in Nature.— Nature is sparing in her use of black, and hides most of it in the earth. Even in the dull days of the year the eye meets notes of colour. Dumas’s ‘‘Black Tulip” is not impossible, nor is the black auricula, and one may artificially induce melanism in a pansy by dropping ink into water, as one may make the yollowhamrner very dark, almost, if not quite, black, by feeding persistently with hemp seed. And there are cattle, cats, pigs, and poultry, not to speak of the occasional sheep, with black exteriors. Also black asserts itself in summer in the small insects, whirligig beetles, which swim the surface of a pool, and in the embryo frogs which congregate in masses at the shallow sides of a pond. The whole tendency in Nature, however, appears to be from darker to lighter colouration. The grey crow is the longest separated from the ancestral stock, and black rabbits and silver greys turned down by themselves, as has been done on one of the islands of the Scilly group for the sake of the pelts, revert, if not interfered with, to the ordinary “ bunny colour.” ■ — Dried Yeast.—

In the Bulletin of Agricultural Intelligence and Plant Diseases (Rome), Dr F. Hayduck describes the remarkable dcvelopment of the dried yeast industry in Germany during the past three years. Heretofore the thousands of tons of yeast produced annually by German breweries as a by-product in the manufacture of beer was almost without value, except for the small amount used in the breweries themselves to hasten fermentation of the wort. Before the days of compressed yeast, much of this product was bought by bakers and housewives, but for many years brewers’ yeast has been a drug on tire market. As a food for livestock yeast has long been known to bo valuable, but its utilisation in this way has been limited by the fact that the fresh product spoils very quickly. The difficulty is now overcome by drying the yeast with the aid of machinery similar to that recently introduced for drying potatoes. Dried yeast keeps indefinitely, and is a remarkably nutritious food, not only for cattle, but also (after the removal of the unpleasantly bitter hop resin that it contains) for human beings. There are now 26 establishments engaged in the preparation of dry yeast, and the demand considerably exceeds the supply.

—Do Plants Feel Pain? — Discussing this topic in the Scientific American, Mr B. Leonard Bastin remarks on the general recognition of the fact that there is no essential difference between the evidences of life in the plant and in the animal. There has never yet been any satisfactory chemical distinction which clearly separates the protoplasm of the two types. One can offer no reason why the vital matter in the plant should not bo capable of performing that which it is seen to accomplish in the animal. Small wonder, then, that Dr Francis Darwin and others should discuss the question of plant consciousness anid seek for signs of memory in the vegetable being. Certainly the socalled “ sleep movements ” in the bean, in connection with which some elaborate experiments have been carried out, appear to show that the plant has, to an extent, the ability to remember. In this case it would appear that the failing of the light in the evening gives the signal for the drooping of the leaflets. It is found, however, that a bean plant which has been kept in the dark for a few days will continue to expand and close its leaflets at about the hours of sunset and sunrise—which seems to indicate memory. An injury which would cause a man the most acute agony will bring only a small discomfort to a jelly-fish. In the same way (proceeds Mr Bastin) the word pain, when used in connection with a plant, can scarcely involve suffering in the sense in which the term is generally employed. Nevertheless, there is small doubt that plants do feel pain to the extent of making them show real signs of discomfort, anid before long wo shall have yet further to revise our views concerning the sensations of plants. Of course, for, some time it has been recognised, for instance, that vegetable tissue is capable of a response to the stimuli of light and heat. It has always been argued that plants could not feci pain or discomfort because they have no nerves. The modem physiologist asks himself the question. What arc nerves? To this there is only one answer—modified and highly specialised protoplasm. The life basis is practically the same in both plant and animal and there is no reason why the protoplasm in the plant should not be able to eat as a rudimentary nervous system. As wo now know, the protoplasm is not confined to the cells of the plant; tiny strands of the living matter arc able to pass through the walls, and thus keep up some sort of communication throughout the entire plant. These threads of protoplasm have often been spoken of as the nerves of the plant. This they are most decidedly not. m the ordinary sense of the word. There is strong reason for believing that in some ways they carry out the functions which are usually performed by a nervous system.