SCIENTIFIC.

Otago Witness, Issue 1754, 4 July 1885, Page 28

SCIENTIFIC.

The doctrine that all the bodies of the higher plants and animals are aggregations of myriads of minute, and in many respects independent, cells, had its origin some fifty years ago. Though now universally accepted by bioligists as an essentially accepted by biologists as an essentially correct generalisation, it has not yet become one of those scientific facts widely known to and accepted by the general educated public. To the "average man" the proposition that his body is a collection of thousands of thousands of microsebpic masses of living.matter, each of which lives its life in more or less harmony with the rest, but to a great extent without any reference to them, is an astounding one. He finds it nearly impossible to realise that in certain respects he is rather a nation t'mn an individual ; that his bodily life is the algebraical sum of the living and doing of hundreds of thousands of cells, much as the vitality of a nation is the resultant of the actions of all its inhabitants. His physical life is to him an entity. In consequence there h nothing which the physiologist finds it harder to make comprehensible to the laity, than that a frog, as a complete animal, maybe killed by the destruction of its nervous system, yet most of its organs remain alive for hours ; also the fact that it is not only possible in many cases to isolate particular organs or cells, keeping them alive for study after killing the rest of the plant or animal, but that this is even necessary, if the working of any complex organism is to be really understood. This popular ignorance, like all other ignorance, has evil results. Much of the disquietude which many persons now feel in regard to physiological experiment is due to the fact that they do not realise that experiments on living hearts or muscles are usually carried out on animals which, as a whole, have been previously killed by destruction of the brain, — Science.

— A matter of surprise and wonder to those who witness it for the first time is the rousing to life of whole colonies of infusoria by the addition of a drop of water to a few grains of earth or dust. These microscopic organisms abound everywhere in water containing decomposing vegetable or animal matter, and some forms may, in a dried state, remain for months or even years apparently dead, to be revived when water is again supplied to them.- Jabez Hogg has been experimenting during the past three years with one form of infusorial life — the rotifars or wheel animalcules — and has even kept dried specimens for a time at a temperature of 200 degrees Fahrenheit, and afterwards exposed them to intense cold, neither process killing them nor greatly diminishing their vital powers. Mr Hogg supposes that as the animal dries it shuts itself up like a telescope, its skin taking an egg-like shape, and that a secreting organ coats the body with a gelatinous envelope which protects it from further change. — It could hardly be credited that there are already in existence paper men-of-war of large toinage. A few years ago, says a correspondent of the American Queen, I was on board the Bdtish man-of-war Raleigh, which was cruising in East Indian waters. Pointing to, the sub-stantial-looking walls of the vessel, a midshipman asked me one day if I knew what those were made of. I answered that probably they were made of teak or oak, and was considerably surprised when he laughed and told me I was all at sea in more senses than one. " The hull of the Raleigh," he said, " is really paper hydraulically pressed. Paper walls, id place of the famous wooden walls of England that tho poets sing about, were adopted by the Admiralty a few years ago as an experiment on a few men-of-war. This is one of them that you are now sailing in through the Indian Ocean." The paper hull idea, as applied to men-of-war, is a good one, at least in theory. In the old wooden and iron ships men were more, exposed to danger. from splinters than direct missiles. Now, paper hulls would at least do away with splintering.

A shot might hit a vessel and pass right through its side, but the hole would be a clean one, and there would be no splinters until the missile encountered some of the internal machinery and compartments. Ido not know whether the English Government has built many of these singular paper boats, but it had one of them at least, in the shape of the Raleigh. — Captain Chetwynd, Inspector of Lifeboats at Home, has submitted a report on his experiments with oil as a means of calming a rough sea. His experiments seem to have been very thorough, all sorts of oils being tried on all sorts of seas. It takes a remarkably small quantity of oil to cover a large area with a thin glassy film of oil. He found that in seas where the rollers were such as would endanger the safely of small boats the oil exercised very pronounced beneficial effects ; it kept the rollers from breaking and left only the modified roll of a harmless swell ; but in surf such as endangers a lifeboat' the calming power of the oil is not enough to make it of practical account. Large breakers in the open ocean would be much more amenable to oiling than shore breakers are, so that Captain Chetwynd recommends vessels to carry a supply of oil and perforated canvas bags, with which to spread it on the waters when the seas are dangerously heavy. He recommends the xise of oil to help small boats over surfs dangerous to them, but thinks that to oil the waves would do little good in lifeboat service.