SCIENCE NOTES.

Otago Witness, Issue 2983, 17 May 1911, Page 84

SCIENCE NOTES.

—Big Legacy For Science. — M. Loutreuil, the son of a French peasant, Who became a wealthy contractor in Russia, has died, promotion of science in France. One hundred tihousand pounds goes to the University of Paris, £14,000 to the Academic d*s Sciences, £4OOO to the Pasteur Institute, and £40,000 to a fund for scientific research. —Snails as Dangerous as Rats.— Snails would hardly be suspected of being —like mosquitoes and rats —dangerous disease-carriers. But (according to Science Siftings) Dr Bairabaschi, an Italian physician, has proved that they may take up typhoid bacilli from leaves on which they feed, and that they may deposit such bacilli on vegetables that are eaten raw. There is a possibility therefore, that snails may spread typhoid fever. —Wireless Lighting Marvel. —

The day may soon come when homes will bo electrically lighted without any wires, for wireless lighting as a possibility is no surprise. So it was merely the expected that happened when M. VaMemair Poulsen, the Danish inventor, pressed the contacts of his aerial transmitter the other day, and thus lighted two incandescent lamps held by his assistant in another room. The miracle will come when the radiated energy can be so directed to a distance that tifoe lose will not be enormously greater than that by wire transmission. —Popular Science Siftings. —lnherited Chflsacteriistics. — "Males inherit the characteristics of their female parent, and females inherit the characteristics of their male parent." Writing in support of this theory, a correspondent of -tibe British Medical Journal says: —"We often notice how rarely a great writer, great poet,' or great artist has a son who follows in his footsteps, although tho daughters may write or paint. In the same way wlhen an amiable woman mairries a bad-tempered man, the soins will be amiable and the daughters bad-tempered." —Forests and Earthquakes.—

,The prevent earthquakes seems to be the most surprising of the many reasons for restoring forests. It is suggested that in such localities as Messina and Southern Italy cutting away the forests has loosened the soil, and this 7nay have given rise to earth faults and added to the earthquake disturbances or their effects. If this theory is correct, of course replanting the trees should again bind »h& loose material with roots, giving the surface its old-time greater stability. Light as a Burglar Expeller.—

Some time ago one of the engineers of a large'electric lighting company devised a system of emergency lighting for residences, by wihicih the turning of a master switch at itihe head of the bed turns on the lights all over the bouse. These lights may be ordinarily opieiratodi by their respective switches in the usual way, but in case tho master switch is turned on they cannot be turned off by means of the individual switches. This means, of course, that once tho master switch has been thrown, any intruder in the house must beat a retreat.

—lcebergs atnd Their Influence.— The captain of am ocean steamer in most oases finds out when his vessel is approaching an iceberg from the men down in the engine : room. That sounds queer, but it is a faot nevertheless. It appears that when a steamship enters water considerably colder than that through wbioh it has been going its propeller runs faster. Such water usually surrounds the vicinage of icebergs for many miles. Whon the propeller's action, therefore, is accelerated without the steam power being increased, word is passed up to till© offioer on the bridge that icebergs may be expected, and a close look-out is established. There are natural reasons for the'propeller acting in this way, and sea captains will assert the same thing. —How to Write Upon Glass. —

There aw many formulas for inks used in making announcement or title slides for tho lantern, writing on negatives, and labelling The following, which comes from France, is a good formula: Alcohol loz, water l£oz, shellac 60gr, borax 90gr, with sufficient aniline dye of the desired colour added to give it density. There is an art in mixing it. First dissolve the shellac in the alcohol and-tihe borax in the water, mix very gradually—almost drop by drop—and apply heat at once should a deposit be fanned, and then and the aniline dye. The proportion of the water should be such as to make the ink of a consistency to flow easily from the pan; some workers, for example, use only 10 drams of water, for it is wondca-ful what a difference a few drops will make —ln Ice for 23 Years.—

The body of a guide, perfectly preserved, has been yielded up by one of the Swiss glaciers alter a period of 23 years. In 1888 the guide fell into a crevasse. His body was lately recovered, its appearance unchanged by its long imprisonment in the ice. There have bo-en other oases of the bringing back of a long-lost body held for years in the close embrace of the' ice. One of the first instancies on record; relates to the Hamel accident, which occurred in 1820 Several 'guides wore swept down by an avalanche and ihurlod into a. crevasse. Hame! prophesied tho 'glacier would yield tihem up in the course of 3000 years, but Professor Forbes, a British expert in Alpine affairs, believed that the end of tho glacier would be reached by tho bodies in 40 years. This statement was considered bold, but its accuracy was borne out by ithe event. In 40 years the flow of ice brought the bodies to light. In 1866 Henry Arkwright was lost in a glacier. In just 31 yeairs his brother received a telegram from the Mayor or Chamonix stating that tho body had been found. Every article of clothing was intact. His name and regiment could be read clearly on his handkerchief, and his gold pencil-case opened and .shut as easily as when he had last used it three decades before. —Sea Water a Liquid Food.— It has hitherto been supposed that marine animals derive their food from each others' bodies, and in the last analysis from plants. However, Puetther has discoveired that the sea contains dissolved food materials, upon which submarine ani/nals, .notably 3ponges, appear to live*, exclusively. A given volume of sea water contains in dissolved condition 24,000 times more carbon than it contains in the form of organisms. Puettner

proved that ono species of sponge, if it were compelled to *>xist upon ready-formed food, could obtain in ono hour only 1-2300 of the quantity of carbon which it consumes in that time; and in order to obtain oven this small quantity it would have to fish over 20 tomes the volume oif sea _ water which would suffice to supply it with all tiho carbon it requires in the farm of dissolved complex oarb>n compounds. Very interesting in this connection is the observed fact that comparatively small quantities of ready-formed food are found in the digestive cavities of the lower marine animals. Hence sea water is, for a great many invertebrate animals, a nutrient fluid from which they absorb food as the cells of animal tissues absorb food from the bodily fluids, animal parasites from the media in which they live, and ail plants •from tlhoir environment. The sea is an inexhaustible reservoir of food. —Freak Shadows. —

Certain curious and apparently paradoxical shadows aire described and explained in the Scientific American. They are kmowiri as "freak shadows," and are seen on the large ponds of crude oil, known as "sump holes," in California. The paradoxical maturo of the freak shadow is that it persists after the substance has moved away. When in the bright sunshine a person stands on the margin of the sump hole, his shadow is oast on the surface of the oil. If he moves very quickly, a dim shadow remains. And the longer a shadow remains after his removal. Experiments have been repeatedly made, and there seems to be no doubt as to the fact. The explanation of the "freak shadow" is an interesting one. It appears that under a hot sun gas is generated in the body of the petroleum, and this rises in minute bubbles to the surface. When a shadow is oast over any part of the surface of the oil the temperature is lowered, and the generation of gas is stopped. And the apparent shadow remains after the removal of the substance until the sun has warmed up the oil sufficiently to generate gas anew. From this explanation it is evident that the "fireak shadow" is not a shadow at all in the proper sense of the word. It is the absence of minute bubbles in the cooled area where the shadow is cast which makes it less luminous than the other parts when the bubbles are rising. Hence it appears darker.