Science Sittings

New Zealand Tablet, Volume XXXIII, Issue 41, 12 October 1905, Page 29

Science Sittings

By • Volt '

Slow Pulse. The case of a healthy man of 61 whose heartbeats only 30 timies a minute, the normal rate being from 70 to 80, has been recorded by Dr. Seiffert, of Berlin. In another case reported the boats Numbered only 22, but the patieai't twas suffering from heart disease. Origin of Chums. Gums are a iboitanical puzzle. Dr. Greig Smith, of Sydney, has wow shown that some are due to bacteria, and 1 he has isolated some species — like that of ' Birabia '^and made them produce their gums in the labor atory. He suggests that all other gums are bacterial products, and that the world's supply might be increased, )by judicious selection of susceptible trees. Maturity of Trees. Though there are oaks living which are known to be more than a thousand years old, the average oak does not live more than 75 years. That is to say, ita -gtrowth extends over that period. The same is trlue oC the ash, larch, and elm. The spruce and fir reach maturity after about 80 years. At the end of that time' their growth remains stationary for some time, and, then decay begins. Colored Rain. The) cuprious phenoßniemon ot colored rain, which occurs in various parts of the world, has at last been explained. In some cases the coloring matter is foiund to too nothing but the pollen dust shaken out of flowers on certain trees at such times as a strong wnnld was blowing over them. Fir trees and cypress trees wheni grouped together in large forests at certain seasons of tho year give of! enormous quantities of pollen, anjd this vegetable dust is often carried many many miles through the atmosphere by the wind, and frequently falls to the earth in a shower of rain. The microscope clearly reveals the origin, of such colored rain, which has on more than one occasion puzzled and mystified the inexperienced. Discovery of the Banana. A correspondent of the ' Liverpool Courier " states that it is precisely 340 years since the banana was discovered byi English ' merchant adventurers '—at all events, 1565 ia the earliest record of such. The reference is! tO 1 'be found in Captain LancLonmiere's second ' Voyiaige unUd Florida ' in that year and the year following. Hero is the passage, and it will be observed the word is spelt ' anajnas ' :— " Dominica is one of the fayrest islands of the West, full of hills, and of very golod smrell. Whose singularities desiring to know as we passed, and 1 seeking also to refresh oursehes with fresh water, I made the mariners cast anker, aftex we had sayled about halfe along the coast thereof. As soon as we had cast anikrr, two Indians (inhabitants of that place) sayled towards us in two canoes full of fruite of groat exoellencie, which they called ananas.' Animals at their Toilet. MJaffiy who have watched animals rolling joyously in the dlust have p'rotebly not regarded the exercise as one of a cleansing nature. And yet the animals so engaged may be saM to have been at their toilet. The dust 'batihsi of some of them are taken to rid them of parasites ; in otlher cases the process is gone through to cleanse their coats from grease. Rats, for instance, aro enthusiastic dust bathers, and so are those quaint little animals the jerboas. When kept in cages the jerboas 1 are supplied with sand to roll in, and thus keep their coats glossy. Even the animals who love bathing in water find it necessary to powder themselves with dust occasianally. Elephants, after a dip in the water, roll in, the dust, and take earth in their trunk and j>o wider their bodies carefully with it. The buffalo, the eland, the hippopotamus, and the rhinoceros la-ko mud bath's occasion all v, whilst amongst the other dust bathers are counted the horse, the ox, the donkey, the camel, and the dog. Amongst the birds, chickens are very fond of a dust bath Diggjin'e; a hole in the ground,, th« chicketi rolls over on its back and throws up 'dust vigorously with beak and claws. After that it runs about with outstretched wings to shake the dust off, the whole process, no doubt, keeping its 1 feathers clean' an/d bright.