Scientific and Useful

New Zealand Graphic, Volume XXXVIII, Issue 2, 12 January 1907, Page 31

Scientific and Useful

AGES IN THE ANIMAL KINGDOM. A great variance as to length of life appears among different animals. Some insects live for only a few hours, while fish, elephants, and turtles are frequently centenarians. The average life of the mosquito is three days. Toads usually live to the age of about fifteen years, while carp have been known to reach one hundred and fifty. Chickens live from twelve to fifteen years; dogs to the age of ten and occasionally fifteen, and parrots to extreme age. These birds have been known to pass the age of two hundred years. Turtles are also frequently centenarians, as are storks, and elephants are said to reach the age of three hundred years. Whal.s have been known to live for four hundred years. . ♦ ♦ ♦ TEMPERANCE. A very large proportion of the people who have devote! considerable study to the subject are of the opinion that the consumption of alcohol is not only unnecessary. but is very distinctly harmful to the human organism. If it be true —as from the earefully-eonsidered conclusions of these people it would certainly appear to l>e—that all alcoholic drinks are far better avoided, every means which can be devised to replace alcoholic beverages by others of a less harmful character is a step in the right direction. One small but not unimportant point which does not appear to have received the attention it deserves is the fact that non-alcoholic beverages are far less easily obtained than those which contain some portion of spirit. - The thirsty wayfarer for a very small expenditure can obtain beer-with the greatest. ease, and at a price which is kept able by the stress of competition. . If.-, however, he desires one of the so-called temperance drinks, lie can only obtain it at a public-house by payment of three or four times its legitimate value. J liitgerbeer. lemonade, and -various other aerated drinks, which can be. sold . t an enormous profit for a penny- a glass are habitually retailed at publichouses for three times this amount. The consequence is that the wavering traveller more often than not will choose the cheaper drink, and take into his system a small quantity of unneeesary and probably harmful alcohol. It should be made a condition of the renewal of all public-house licences that the usual non-alcoholic beverages should be kept in stock, and sold at the price which every -weet -hop finds sufficiently profitable. 4-4-4-TIMING STENOGRAPHY'. The inventor of what is known as the Oxford system of shorthand, which claims to be considerably more rapid than the older stenography, has produced an ingenious little machine, principally with the object of demonstrating the truth of this claim. By means of this device the actual time occupies! in writing various words is accurately r< orded. and different systems of shorthand can be compared in this respect with one another. The machine pays out a graduated'tape at the rate of a -yard a second, and as each yard is divided into sixty parts the time occupied in writing any word or combination of word- is measured to the sixtieth part of a second. The little machine shows exactly the length of time occupied by each portion of the outline, and. according to the inventor, it demonstrates in a remarkably effectual manner the great superiority in point of speed of the Oxford system over what he calls the old sty le short I>a " ♦ ♦ ♦ GREEN MANI RING. The beneficial action of green manures cn certain soils has long been recognised; but the true explanation of the effect has not been properly understood until recenth. Green manuring affects the soil

in several ways, principally by the mechanical action of the gases evolved during decomposition of the vegetable matter by the solvent effect upon the soil constituents of the acids, to whieh decomposition gives rise, and by the conversion of atmospheric nitrogen into nitrogenous compounds, which become the food for future crops. Mention has been made in these columns of the recently successful attempts to fix atmospheric nitrogen by electrical means; possibly in the future this method may prove to be more economical than the fixation by means of leguminous crops. In the meantime, however. green manuring produces the change

more cheaply than it could be accomplished by any chemical or electrical process yet devised. Recent experiments have proved beyond doubt the leguminous crops possess the power of fixing atmospheric nitrogen by virtue of certain bacteria generally present in the soil. It is absolutely essential to the success of the manuring that this specific organism should be present, and although it is to be found in most soils, some do not possess it, and in this ease some form of inoculation becomes necessary, or the green manuring fails of its effect. The United States Department of Agriculture prepares a culture of this bacterium, an.l supplies it to farmers, with full directions as to its employment. Either the seed or the soil itself may be inoculated with the preparation, and in either case the resulting organisms take possession of the plant and enable it to produce the nitrogenous compounds whieh are so necessary to the welfare of succeeding crops. ♦ ♦ 4SALT WATER FISH IN FRESH WATER. An interesting experiment that should have far-reaching results has just been brought to a successful issue in Germany. It has been proved that deepsea fish can be acclimatised in fresh water and will live and breed in outrivers. A number of different kinds of fish were taken from the sea, including whiting, herring. sole, and flounders, and kept in a pond of salt-water. The percentage of salt was gradually lessened by the addition of fresh water until finally no salt remained. Practically no material difference took place in the fish, whieh were as lively and healthy after the treatment as when taken out of the sea. encouraging has been the result, after a test extending over several months, that the fish are now being introduced into the various rivers and fresh-water lakes, in order to bring the experiment to a practical issue. What changes may- take place in the nature and habits of the fish remain as yet to be «ean, as does also the question of their market value. The success of this experiment will entirely change the fishing' industry, and unit prove an especial boon to communities far removed from the sea board. It will enable them to have a constant supply of fish in their own waterways, which they will be able to buy at au infinitely smaller cost than at present, + 4- ♦ HEALTH AND THE HAIR. According to an article in " L’Hlustration,” a Japanese physician has been experimenting recently to ascertain whether the growth of human hair is affected by serious illness (as is the ease with the nails), and some very remarkable results have been brought to light by his investigations. He has found, for instance, that every serious illness has a marked effect in diminishing the thickness of the individual hairs, and by microscopic examination he claims to be able to ascertain whether an illness has recently taken plaee. and to give its duration. The illness has the effect of making the hair thinner along a part of its length, and the length of the thin portion is proportional to the length of the illness. It is suggested that this fact may have importance. for instance, in a question of identification.