In the class of vapours, ammonia proved fatal in one case, and harmless in another; muriatic acid stupified in two, and killed in twenty-four hours. The vapour of nitric acid was equally fatal with sulphuretted hydrogen; and, in alcoholic vapour, at a temperature of 74°, 'for a few minutes the fly shewed increased activity; in a few more, it became nearly motionless; after about a quarter of an hour, it appeared to be torpid. Now, exposed to the air of the room, in a few minutes a slight motion of its feet was seen; after a couple of hours, it was nearly as active as before the experiment; two hours later, it was found dead.' The same effects, with slight variations, were produced on other flies. With ether, cessation of motion was almost instantaneous, followed, however, by revivification, except in one instance: brief immersion in chloroform did not prevent revival, but an exposure of eight minutes killed: camphor and turpentine were both fatal: with attar of roses, musk, or iodine, no ill effect was perceptible.
The experiments with prussic acid are worthy the attention of entomologists, with whom it is often a matter of importance to kill an insect with the least possible amount of injury. In these instances, the plan pursued was to charge a small tube with the acid, and place it inside that containing the insects. The vapour of 1-16th of a grain was sufficient to destroy bees and flies; and that of seven grains proved fatal to large beetles, and the largest kind of bees. Although as yet the investigation has taken but a limited range, it will be seen that it opens a wide field of research: the next step will be to group or class those agents which appear to have produced similar effects. It is remarkable, as Dr Davy observes, 'that most of the substances which, even in minute portions mixed with common air, prevent the slow combustion of phosphorus, as indicated by its shining in the dark, have the effect, on the insects on which they were tried, of suspending animation.'
He says further: 'Some of the results may not be undeserving notice for practical purposes—as those in the instances of sulphuretted hydrogen, oil of turpentine, and camphor, in relation to the destruction of parasitical insects, whether infesting plants or minerals, or to the preservation of substances from the attacks of insects. To be applicable to the preservation of plants, of course it is necessary that the agents to be used should not exercise on them any materially injurious effects. This must be determined by experiments made expressly for the purpose. The few trials I have yet made on seeds seem to shew, that the steeping them in a solution in water of sulphuretted hydrogen has not prevented their germination. The seeds tried were mignonette, cress-seed, and that of a Nemophila: analogy—namely, that of steeping the seed of the cerealia in a solution of the white oxide of arsenic, is in favour of the same conclusion. Further, for the preservation of articles, whether of clothing or furniture, it is hardly less necessary that the substances to be employed should have no offensive odour. Judging from the effects of attar of roses, and from what we know of scented woods not being liable to be attacked by insects, the probability is, that any volatile oil of agreeable perfume will answer the purpose required, and prove a true instance of the utile et dulce combined.
'As carbonic acid gas, and some of the other agents mentioned, produce merely a temporary torpor, it may be a question whether this gas, or simple immersion in water, may not be advantageously substituted for the fumes of burning sulphur, destructive of life, at the yearly gathering of honey; the former, indeed, may be said to be in use in the Levant, where the smoke of the fire of leaves, in which the carbonic acid generated may be considered as chiefly operative, is employed to stupify the bees preparatory to the spoiling of their hives.'
CHILDREN SUCKLED BY WOLVES.
This subject is one which will not be unwelcome to those whose faith in the myths of Roman history has been dissipated by Niebuhr and others: they may still believe the story of Romulus and Remus and the wolf. The Honourable Captain Egerton, in a communication from India, says: 'Colonel Sleeman told me one of the strangest stories I ever heard relating to some children, natives of this country (Oude), carried away and brought up by wolves. He is acquainted with five instances of this, in two of which he has both seen the children and knows the circumstances connected with their recapture from the animals. It seems that wolves are very numerous about Cawnpore and Lucknow, and that children are constantly carried off by them. Most of these have, of course, served as dinners for their captors, but some have been brought up and educated by them after their own fashion. Some time ago, two of the king of Oude's sowars (mounted gendarmes), riding along the banks of the Goomptje, saw three animals come down to drink. Two were evidently young wolves, but the third was as evidently some other animal. The sowars rushed in upon them, captured the three, and to their great surprise found that one was a small naked boy. He was on all-fours; like his companions; had callosities on his knees and elbows, evidently caused by the attitude in moving about; and bit and scratched violently in resisting the capture. The boy was brought up in Lucknow, where he lived some time, and may, for aught I know, be living still. He was quite unable to articulate words, but had a dog-like intellect—quick at understanding signs, and so on. Another enfant trouvé, under the same circumstances, lived with two English people for some time. He learned at last to pronounce the name of a lady who was kind to him, and for whom he shewed some affection; but his intellect was always clouded, and more like the instinct of a dog than the mind of a human being. There was another more wonderful, but hardly so well-authenticated, story of a boy who never could get rid of a strong wolfish smell, and who was seen, not long after his capture, to be visited by three wolves, which came evidently with hostile intentions, but which, after closely examining him—he seeming not the least alarmed—played with him, and some nights afterwards brought their relations, making the number of visitors amount to five—the number of cubs which composed the litter from which he had been taken. There is no account of any grown-up person having been found among the wolves. Probably, after a certain time, the captives may have got into a set of less scrupulous wolves, not acquainted with the family: the result is obvious.'
ELECTRO-MAGNETIC MACHINE.
The electro-magnetic machine invented by Professor Page, has from time to time been noticed in our Journal, and we have now to give a further account of this interesting mechanism, as furnished by an American periodical. It appears that several of these machines have lately been submitted to critical examination by competent authority at Washington, and with very favourable conclusions. The principle has already been explained—namely, the alternate rising and falling of an iron rod within a helix through which an electro-magnetic current is made to pass: when the current is on, the rod rises, and remains, as it were, self-suspended, equidistant from all parts of the surrounding helix; and falls as soon as the current ceases by breaking contact with the battery. The 'rod' of one of the machines submitted to the examination weighs 350 lbs.: no sooner, however, was contact made, than it rose into its position. 'Dr Page then stood on the top of the rod, which not only sustained his weight, in addition to its own, but he pushed with his hands against the ceiling, increasing the downward pressure on the rod, which was only acted upon as a powerful spring would have been, but still maintaining its perpendicular position concentric to the inner surface of the helices. I held,' says the reporter, 'an iron rod in my hand, with the end of which I touched that of the suspended rod. I could not detach it by pulling or jerking, and could only alter its position so as to cause the annular space to become eccentric instead of concentric. The instant the battery was disconnected, the rod fell to the floor with its full force.'
By moving the wires from the battery up and down outside the pile of helices, it was clear that an upward and downward movement of the rod would follow, 'and that a shackle-bar attached from this oscillating rod, and to a crank, would convert this reciprocating motion into a continuous one.' To this contrivance the name of 'Jumper' was given, of which one was exhibited, the helices weighing 800 lbs., and the rod 526 lbs.; and by the means above mentioned, it has been converted into a working-engine, with a twelve-inch crank, and a fly-wheel of four and a half feet in diameter. 'On the outside of the helices,' to quote the description, 'was placed a line of pieces of metal, so arranged as to render the attachment with the battery and its necessary alternations performable by the engine itself. Before starting the engine, I tied an arm of the fly-wheel, at one-third greater distance from the centre than the length of the crank, to an upright beam of twelve inches diameter, which formed part of the frame of the engine. The cord used was the better kind of bed-cord, of great strength, nearly three-eighths of an inch thick. This was passed twice round the fly-wheel arm and post before being tied, and with pieces of sole-leather intervening, to prevent the cord being cut by the corners of the post. Such a fixture, I am confident, would have held a five horse-power steam-engine from starting, with full pressure of steam on the piston, and no previous motion. Not so, however, with this engine, for the breaking of the cord and contact with the battery occurred at the same instant of time, leaving an impression in the beam to the depth of the cord, despite the protection of the sole-leather.' The engine continued to work in the most satisfactory manner; and Dr Page attached a circular-saw, which was used in wood, to a depth of six inches, and at a speed such as could be anticipated from the power which we afterwards found the engine to possess.
Careful experiments made to test the power of the engine, shewed it to be equal to seven horse nearly; and the estimate for consumption of acid and use of zinc is twenty cents for each horse-power per day of twenty-four hours. The escape of acid vapours from the batteries is an evil that will have to be guarded against, to prevent the pernicious effects produced in several electro-plating establishments, where the health of the workmen has been seriously injured by the liberated gases. This defect being overcome, Professor Page's electro-magnetic engine may become highly valuable in engineering and manufacturing processes. To quote the conclusions of the report—'the cost will be less than that of a steam-engine of the same power: the weight will be but one quarter, if boilers and contents be taken into account: the expense of firemen and engineers is dispensed with: buildings, and stocks of goods, and vessels may be more cheaply insured than when steam-engines are used, as there could be no risk from explosion or fire: the expenses are only active while the machine is positively in action, whereas an ordinary steam-engine continues its expenses whenever the fire is burning.