Science Notes.

Freethought Review, Volume I, Issue 9, 1 June 1884, Page 4

Science Notes.

Cold diminishes the conducting power of nerves for nerve force, whereas it increases the conducting power for electricity, of solids or fluids. The crushing of a nerve, or tying it tight, and afterwards relaxing it, will interfere with future passage of the nerve current, whereas bruising will have no effect upon the metal wire. Nerve force hence, it is clear, differs from electrical force, although it would appear to be correlated to it, in the same way that it may be said to be correlated to chemical force, with the heat developed in the muscle, and even with the peculiar molecular motions which produce muscular contraction and all its physical and mechanical consequences.—' Science Monthly.'

M. Miquel, who is one of the leading authorities on the subject of air germs, has recently conducted experiments at the Montsouris Laboratory which prove that all gaseous antiseptics are almost useless. Dr. Landur long ago maintained the inefficiency of the vapour from chloride of lime, phenol, or perfumes, to kill germs, and M. Miquel has demonstrated the correctness of his views. He finds that the vapours of chlorine, bromine, iodine, and chloroform take several weeks to Kill the microbes, and that they do not act at all unless present in such quantity as to render the air irrespirable. Consequently, so long as the air is breathable it may contain living germs. M. Miquel considers mercury to be the most practically useful antiseptic known.

At a meeting of the Royal Society of Edinburgh, on January 21st, Mr John Aitkin read notes on the recent red sunsets. There were two theories regarding them. One was that they were due to an overabundance of dust in the air—meteoric or volcanic. Mr. Proctor held that the dust was meteoric, and most other people that it was volcanic. He (Mr. Aitken) thought they had a ready means of determining whether the phenomenon was due to the watery vapour or dust. Watery vapour acted as an absorbent, and the light of the sun in passing through it had certain rays destroyed ; but, if the colour was produced by dust, it would act as a sifting agent, and would not destroy the rays. If it were dust, then, they ought to have somewhere in the sky the complementary colours to the brilliant reds they found in sunsets. He thought they had those complementary colours. If they had examined the sky overhead, they would have found that the blues were very deep and the greens more brilliant than any of them had ever seen before. These blues and greens were complementary to the reds. The rays, therefore, had not been destroyed, but reflected by dust; and for that reason it appeared to him that dust in the air was the cause of the fine sunsets, and not watery vapour.

The Liverpool Post states that a discovery has recently been made in electric lighting which, it is hoped by the patentees, will solve the question how to bring the electric light into operation for domestic use. It has been found possible, it is said, to produce the light without the aid either of engines or dynamos. All that is required are merely the ordinary metals and carbons and a peculiar kind of acid. These are put into an ordinary cell, and immediately the acid is poured in and the continuity established the electric force begins to develop. Experiments have recently been made by Mr. E. H. Thompson, the well known electrical engineer, by which a 20-candle light has been kept continuously going by the electric current being generated in this way; and the experiments have been pronounced a decided success by all who have witnessed them. By this process no accumulators are required, and the batteries can be so made as to supply one or a hundred more lights, according to the number required. The new light (which is called the Acme), it is asserted, will be admirably suited for country residences, yachts, &c, and can, it is estimated, be produced at a price about the same as that of gas, with very superior illuminating power, while. the original expense of providing 20 lamps of 20-candle power each is calculated at about £SO. ._,...

An instance of poisoning from eating tinned mutton is reported from Glasgow. Of those who had partaken of it two boys died; while several other persons were attacked with violent vomiting and purging, but recovered. It is not probable that in this case, says the Lancet, the tin had much to do with the result. The salts of lead, such as might be formed by the action of putrescent animal matter, of the nitrates, derived from it, or of salt, are capable, no doubt, of producing the symptoms in question, if taken in large quantity; but it is hardly possible that the tin can have been corroded to this extent. The unfortunate circumstance presents to us rather an example of septic irritation, due, it would seem, to putrefaction of the meat. This might easily arise either from the use of tainted meat to begin with, or from the admission of air during or after tinning. We have not adverted to the possibility of adulteration with injurious foreign matter. Such a possibility naturally presents itself, and no doubt receives attention from the authorities who are investigating the case. No evil need result from eating preserved meat if it be carefully prepared and selected, but this incident, and others like it, teach us by sharp experience that more attention is required for our dietetic economy than is now given to it.

M. Petrie's recently published book throws a new light upon the mechanical means employed by the builders of the Pyramids. He traces on the huge stones of which the Pyramids are built, the undoubted marks of saw cutting and tubular drilling. He believes that the tools employed were of bronze, and asserts that this metal has left a green stain on the sides of the saw cuts. Jewels to form cutting points, he believes to have been set both in the teeth of the saws and also on the circumference of the drills. (If this be true, rock boring diamond drills are no new things). He has even detected evidence of the employment of lathes with fixed tools and mechanical rests.