At last a parliamentary committee has been appointed to collect evidence on the condition of the Thames and other rivers, on the best means of regulating them, and of economising the rainfall so that there shall be a sufficient supply of water at all seasons. This is a great question: human requirements confronting the forces of nature with a view to harmonious co-operation. According to a statement made at a meeting of the Institution of Civil Engineers, the quantity of water that flows daily over Teddington weir is 3,223,125 tons; hence the Thames will count for something in the inquiry. Besides which, we may remember that the commerce carried by the royal river amounts to nine million tons annually.
At a recent meeting of the Franklin Institute, Philadelphia, there were exhibited an Odontograph for laying out the teeth of gear-wheels; an exhaust nozzle for quieting the noise of safety-valves and escape-pipes; an aspirator for ventilating mill-stones, and a horse-shoe intended to prevent slipping on a smoothly paved road. Readers desirous of further particulars must write to Philadelphia; but if that 'quieting nozzle' can only be made available, passengers at railway stations and on board steamboats will be spared the deafening roar that now annoys them, and will feel grateful accordingly.
The last published volume of Transactions of the Royal Society of Victoria contains a paper entitled, 'Is the Eucalyptus a Fever-destroying Tree?' a question which, as our readers are aware, is not less interesting here in Europe than in Australia. Baron von Mueller, government botanist at Melbourne, has described more than one hundred and thirty species of Eucalyptus: some grow into forests of great extent both on high and low table-land, others form dense desert scrub, while others are so distributed as to impart a park-like appearance to the landscape. The leaves are evergreen, and so arranged that the light and heat of the sun fall equally on each side; and the roots are dispersive and drain water largely from the soil. Besides the general constituents of a ligneous vegetation, the Eucalyptus contains a gum-resin, a volatile acid, and a peculiar volatile oil. The finest forests, Eucalyptus amygdalina, extend inland about one hundred miles, beyond which the scrub species prevail. When by vicissitude of season the seaward species are poor in volatile oil, then the scrub is rich, and vice versâ. The extent of scrub and forest in the three colonies of New South Wales, Victoria, and South Australia is so great that the quantity of oil therein contained is estimated at 96,877,440,000 gallons. On this Mr Bosisto, the author of the paper above referred to, remarks: 'Considering that the same condition exists throughout the major part of Australia ... we cannot arrive at any other conclusion than that the whole atmosphere of Australia is more or less affected by the perpetual exhalation of those volatile bodies.' The aroma thereof would be disagreeable, were it not that 'volatile oils have the power of changing oxygen into ozone while they are slowly oxidising.' It can hardly be doubted that the influence on climate must be important. 'Let,' says Mr Bosisto, 'a small quantity of any of the eucalyptus oils, but especially the oil of Eucalyptus amygdalina, be distributed sparingly in a sick-chamber, or over any unpleasant substance, or add a small quantity to stagnant water, and the pleasure of breathing an improved air will immediately be manifest. The application of this to the climate of Australia has great force, for it is acknowledged that we possess about us, both in bush and town, a large amount of active oxygen, made frequently doubly so by our vigorous vegetation.'
The conclusion from the whole series of facts is, that the Eucalyptus is a fever-destroying tree. Baron von Mueller states that the Eucalyptus amygdalina in favourable situations grows to a height of four hundred feet, that it yields more oil than any other species, and bears the climate of Europe. The species of quickest growth is the Eucalyptus globulus.
In a communication to the Royal Astronomical Society, Mr W. M. Williams points out that obscure heat, such as that radiated from sun-spots, is much more largely absorbed by our atmosphere than the heat from the luminous parts of the sun's surface. Consequently the obscure heat exerts an influence on terrestrial climate as well as the luminous heat: the former in preventing or modifying the formation of clouds in the upper regions, and in producing thereby meteorological results which would be an interesting study. An illustration of what is meant by this is afforded by a well-known phenomenon, namely the general clearness of the sky during full moon, the clouds having been dissipated by the obscure heat-rays reflected from the moon's surface.
If observations of the difference of absorption between the two kinds of heat could be made at different heights, we should have, as Mr Williams says, 'a new means of studying the constitution of the interior of the sun and its relations to the photosphere. Direct evidence of selective absorption by our atmosphere may thus be obtained, which would go far towards solving one of the crucial solar problems—whether the darker regions are hotter or cooler than the photosphere?'
St Bartholomew's Hospital Reports contain an article by Dr Hollis in which an attempt is made to clear the study of mental physics of some of its obscurity, and to shew what are the functions of the brain and the way in which they may be studied. Examples are given of the effects of disease: a letter-sorter in the Post-office had experienced a failure of memory during two years, could not continue his employment, and eventually died. A large tumour was found in the substance of the left temporal lobe of the brain, which probably accounted for the loss of memory and inability to retain a mental picture of the pigeon-holes into which the letters were to be sorted. The organs of the brain were there, but their proper action was disturbed by the growth of disease, and the man of necessity ceased to be a letter-sorter. In concluding his article, Dr Hollis warns 'students of this seductive branch of medical science not to attempt to localise in the cortex too closely the several faculties of the mind. It is preposterous,' he remarks, 'to expect that similar cells are reserved for similar functions in all human brains, knowing what we do of the great diversity in man's mental nature, his various occupations, proclivities, and talents. Beyond the fact that there exists in our brains a posterior or retentive system, and an anterior or expressive system, our knowledge of this organ will not at present permit us to go.'
The effect of ether and of chloroform as anæsthetics, is attracting considerable attention. It is alleged that with chloroform, vascular paralysis frequently precedes respiratory paralysis; and an amount of chloroform insufficient to cause paralysis of respiration will often produce vascular paralysis, accompanied by such a diminution of blood-pressure as to render artificial respiration useless, since interchange between the gases of the air and blood does not take place. In this case artificial respiration does not recall life, and respiration ceases when artificial aid is removed. Experiments made with nitrite of amyl demonstrate its value as an antidote to the dangerous effects of chloroform; for which reason an American physician remarks: 'In the light of our present knowledge, it seems to me that humanity and science alike require that, when chloroform is used as an anæsthetic, the nitrite of amyl should be at hand, as one of the remedies whose efficiency is to be tested in case of impending danger.'
Medical practitioners in Calcutta have had their attention called to a species of parasite before undescribed, which has been found in large numbers in the intestines of persons who have died of cholera. According to a description recently published in the Journal of the Asiatic Society of Bengal, it is the Amphistoma hominis. 'I have never seen such parasites,' writes Dr Simpson, 'and apparently they are unknown to the natives. They are of a red colour, size of a tadpole, adhering to the mucous membrane, by a circular open mouth which they have the power of dilating and contracting.' It is to be hoped that these somewhat mysterious tormentors will not make their appearance in Europe. By way of precaution, we would just hint, 'See that you drink pure water.'
Of petroleum furnaces of a small size suited for high temperatures we find Quichenot's (lately noticed in these columns) is not the first attempt made, one having been introduced some years ago by Griffin, an English manufacturer. The difficulty with all petroleum furnaces is to keep them lighted until the casing or crucible is sufficiently hot to do this itself. The special liability which petroleum furnaces have to blow out at first, is to a great extent if not entirely overcome in Griffin's by the use of a wick. We are told by those who are practically conversant with the subject, that there are many difficulties in the use of petroleum as a fuel for furnace-work on a small scale, which, however, may be in a measure overcome by skilful management. But for small furnace operations it is now generally admitted that there is no fuel so well adapted as gas. A gas furnace of an entirely novel construction was introduced about a year ago by Mr Fletcher, F.C.S., of Warrington, in which the gas is burnt by an arrangement similar to Giffard's Injector, and requiring no more air than an ordinary small foot blower will supply with ease. The whole arrangement is exceedingly simple; and a refractory clay crucible can be fused in less than half an hour by an apparatus which (blower included) can easily be carried in one hand. Of gas furnaces not requiring a blast, the pioneer was Gore, who made the first draft furnace, burning gas, which would fuse cast-iron; and the principle made use of by Gore—that is, the subdivision of a large flame by air-spaces—has been since made use of successfully in many forms by different makers; but the maximum temperatures obtained in Gore's furnace have never yet been exceeded by any maker without the use of a blast. The nearest approach to a draft furnace giving really intense heats is, so far as we can ascertain, the Injector furnace of Mr Fletcher, which requires only about one-fifth of the air consumed to be supplied by blowing, the remaining part of the air being drawn in from the surrounding atmosphere by the action of the furnace itself.