Scientific and Useful. 1

Mataura Ensign, Volume V, Issue 224, 26 January 1883, Page 5

Scientific and Useful.

• ■■ — , ■ \ UNDEBGBOFND TEMPEEATUBE. The report of the British Association: Committee v on - I'TTnderground Tempera* iturei" shows how impossible it is to give a mean rate of. increases. It states that the result of fourteen years' observation shows that the increase of subterranean temperature varies in' its rate of increase dbwiiwards, amongst other places, from 1 deg. P. per 130 ft. at the Bootle Waterworks, Liverpool, 1392 ft. deep, to 1 deg. P. every 34ft. at the Slitt Mine, Weardale, Northumberland, 660 ft. deep. A mean increase of temperature, per foot is found from these figures to be '01563, or ljleg. P. in 64ft.. EMBALMING. Taxidermists, who not unfrequently have opportunities to preserve animals (pachyderms and snakes, or varieties in flesh), should take notice of the receipt given by the" Italian embalmers, which a contemporary has carefully produced. The principal Italian embalmers keep their special processes a secret, although the chief steps are well known. The process of embalming is stated to consist of five steps. First, cold water is injected through the whole circulatory system until it issues quite clear ; this may take as long as five hours. Alcohol is then injected for the purpose of abstracting all the water from the body; this is followed up by the injection of ether, to dissolve out the fatty matter. This injection is carried on for several hours — in thin subjects for two, in very fat ones for even so long as ten hours. After this a strong solution of tannin is slowly injected, and full time is allowed for its soaking into all the tissues ; this takes from two to five hours. Lastly, the body is exposed for from two to five hours to a current of warm air, which is previously dried by passing it over heated chloride of calcium. T^lie body can then be preserved for any length of time without undergoing change, and is as hard as stone. HOW HITCH SHOULD WE BIT? There are some good rules for feeding as to quantity. When our food is simple and natural in kind and quality, and mode of preparation, there is little danger of eating too much. There is little danger, for example, of eating too many grapes, apples, pears or bananas. Salt, sugar, spices, and luxurious cooking tempt to excess. With men, as with animals, a natural diet is self-limiting, and we are disposed to stop when we have got enough. The more artificial the food, the more elaborate and . luxurious the feast, the more the liability to overload the stomach, overtask the digestive power, and overweight the forces of life. Simplicity of diet is a condition of health, and promotes longevity. The quantity of food which enables a man to do his daily work without loss of weight, is precisely what he requires. He supplies the daily waste — no more and no less. This quantity may vary a little with each individual, but everyone can easily ascertain his own measure of requirement by reducing the quantity of daily food until he finds a balance of force and weight. It is my opinion that the average quantity of waterfree aliment required, say by business and literary men, is 12oz. Men of great muscular activity may require 16oz. to 20oz. I have found myself in very good condition for 'sedentary work on Boz. or J. 003. When anyone is in good condition for his work and keeps his normal weight, he h»s food enough. My advice is, find this quantity by experiment, and then, habitually keep to it>--Jfr. NicholU,

MARINE FAUNA OF LIGHT AND FAUNA OP DARKNESS. It is remarked by Herr Fuchs, in a recent memoir, that while the littoral or shore animals inhabiting the banks of seaweed, corals, and shells, do not extend much beyond 30 fathoms, one finds at about 100 fathoms, over the whole earth, that deep-sea fauna, whose similarity of composition every where is so easily recognised, the chief types being deep sea corals, lampshells, glass sponges, featherstars, sea-urchins, glasmopodia, and flat fishes. At about 50 fathoms generally (it is proved by observation in the most diverse seas) the first of the deep- sea fauna are met with, and that depth may be taken to indicate the critical zone between + he two fauna. In the tropics the two are separated by a verj sterile region, reaching from about 30 to 80 , fathoms ; in temperate and cold seas they, mix in abundance in the critical region. Now, it can be shown that neither the temperature nor the chemical composition, nor the movement of the water, will account satisfactorily for this vertical distribution. One factor remains to be considered — viz., light — and it is remarkable that the depth to which light penetrates in sea water is stated by Secchi, Pourtales and Bougner (on basis of experiments) to be between 43 and 50 fathoms. Herr Fuchs infers that the shore fauna a 1 c fauna of light. The deep sea fauna, fauna of darkness. This view gains support from the fact that in some places where the light limit is higher, the deep sea fauna extends higher, and in fresh water lakes, where the light penetrates to greater depths, the shore fauna reaches further down. Again, many deep sea animals have either uncommonly large eyes like nocturnal animals, or are quite blind. They are mostly pale and colourless, or entirely of one colour; and many have Strong luminosity, while none such are found among snore antmalai Tho ao-calWst pelagic animals, which spetid their life swimming in the open sea, and never need to visit the ground, have much similarity to the deep sea fauna. The great majority are animals of the darkness ; remaining in the dark depths by day, and only coming to the surface at night, and they are largely phosphorescent. The conception of the deep sea fauna as fauna of darkness accounts simply for their presence being wholly independent of temperature, and for their being found at nearly the same depth over the whole earth. There are also interesting points of similarity between them and the fauna of grottoes and caverns. The view under consideration has important bearing on geology and palasontology. Off the Brazilian coast, in the Red Sea, and elsewhere, there are at depths of six to eight fathoms, extensive catacomb-like formations of coral, in the dark recesses of which, on the above hypothesis, a fauna of the deep sea character may be looked for, which, in> I such a position, might perplex some future geologist. Experience shows (according to Herr Fuchs) that the difference i between littoral and deep sea fauna now lound in seas can be traced, in a quite similar way, throughout past formations. f." ; ' . t . — - |W^ IN EVOLUTION. 32-% XL animal life is not subject to death, la&cording to the American. Journal of Sidence. Examining though a microscope 6n\ of those minute single-cell creatures known as a protozon, the Journal remarks that Ye see it extending into an ellipsoidal figure, which becomes for a time longer and longer. It then begins to contract about what we may, for the sake of popular intelligibility, call its equator. It assumes the form of two nearly globular bodies, connected dumb-bell-like, by a narrow neck. This neck becomes narrower, and at last the two globes are set free, and appear as two individuals in place of one. What are the relations of these two beings to the antecedent form and to each other P We examine them with care ; they are equal in size, alike in complexity, or rather simplicity, of structure, Wa cannot say that either of them is more mature or more rudimentary than the other. We can find in their separation from each other no analogy to the separation of the young animal or the egg from its mother, or to the liberation of a seed from a plant. Neither of them is parent, and neither offspring. Neither of them is older or younger than the other. The process of reproduction, or rather of multiplication, must, so far as we can see, be repeated in the same manner for ever. Accidents, excepted, they are immortal, and frequent as such accidents must be, the individuals whom they strike might, or rather would, like the rest of their community, have gone on living for ever. It is strange, when examining certain infusoria under the microscope, to conaider that these frail and tiny beings were living not potentially in their ancestors, but really in their own persons, perhaps in the Laurentiaa epoch. THE HEALTHINESS OF HIGH HOUSES. At the Sanitary Congress lately, the Hon. F. A. Russell read a paper on " The improvement of the climate at a slight elevation." He said recent observations had completely disproved the rule, which only thirty or forty years ago was believei to represent facts, that temperature decreased regularly with increasing altitude. From the results of the various observing stations they found that a general agreement existed whicli proved that at points artificially or naturally raised above the surrounding district the range of temperature was smaller. It was found that at a height about equal to that of the upper rooms in a high house, a more equable and drier climate prevailed than at lower levels, drier than at the seaside, and with a daily-range not much greater, and much less cold on the coldest and foggy nights than down bolnw. The practical conclusions seemed to be that invalids and delicate persons should generally be placed in high sheltered situations in the highest rooms of a house, and by no means on a ground floor *, that a climate resembling that of the seaside, but less damp, could oe obtained by living at the top of a high house; that every house ought to be built on arches, or thoroughly ventilated below, and raised on piers above the ground level ; that no house or cottage which was not ventilated underneath, with damp-proof walls, should be considered habitable ; and that in this country no house should be considered habitable of which the floor was on a level with or below the ground,