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pressure of wind is 671bs. per square foot of a plane surface, or 321 lbs. per square foot of the plane projection of a cylindrical sur face ; so that here it may be considered that there is an excess of stability. A SEARCH FOR SOLID BODIES IN THE ‘ATMOSPHERE. By R. Angus Smith, Ph.D., F.R.S. I have so frequently for many years attempted to find, and have found, organic substances which have passed from the air into liquids in which they were collected, that perhaps the society will scarcely attend to another attempt, although it in dicates, I think, some progress. It was in the year 1847 that I first collected what I believe was matter from the respiration and perspiration, and foimd that as it was kept it grew into distinct confirmed forms. Whilst examining some matters relating to the cattle plague I found one or two remarkable points. I had before that time used aspirators to pass the air through liquids, except in the oxidation experiments. At that time I used simply a bottle which contained a little water. The bottle was filled with the air of the place, and the water shaken in it. The difference of air was remarkable. A very few repetitions would cause the liquid to be muddy, and the particles found in many places were distinctly organic. Lately I tried the same plan on a larger scale. A bottle of the capacity of T t.oj>_ c.c. was filled with air and shaken with water. The bottle was again filled and shaken with the same water, and this was repeated 500 times, nearly equal to 24 million cbc., or 2495 litres. As this could not be done in a short time, there was considerable variety of weather, but chiefly dry, with a westerly wind. The operation was conducted behind my laboratory, in the neighbourhood of places not very clear, it is true, but from which the wind was blowing to all parts of the town. I did not observe any dust blowing, but if there were dust, it was such as we may be called on to breathe. The liquid was clouded, and the unaided eye could perceive that particles, very light, were floating. When examined by a microscope the scene was varied in a very high degree—there was evidently organic life. I thought it better to carry the whole to Mr. Dancer, and to leave him to do the rest, as my knowledge of microscopic forms is so trifling compared to his. It may, however, interest the society to hear a few of these previous attempts, the latest made till recently. I shall there fore read from a report to be found in the appendix to that on the cattle plague. Mr. Crookes also brought me some cotton through which air from an infected place had passed. It was examined at the same time. Taking cotton in the mass nothing decided was seen ; but when it was washed some of the separate films were coated over with small nearly round bodies, presenting no structure, or at least only feeble traces of it, and perhaps to be called cells. I had not sent gun-cotton, as I intended, to Mr. Crookes, fearing the rules of the post; otherwise there would have been more certainty that the bodies spoken of did not exist previously on the cotton. However, Mr. Dancer, who has examined cotton with the microscope oftener than most persons, even of those experienced in the subject, had never observed a similar appearance. The liquid had also a number of similar bodies floating in it. It was then that Mr. Crookes sent a liquid which he had con densed from the air of an infected cowshed at a space a little above the head of a diseased cow. It was also examined, and it presented similar indications of very numerous small bodies. Not being a professed microscopist, I shall not attempt a de scription, but add that they clearly belonged to the organic world, and were not in all cases mere debris. We found also one body a good deal larger than the rest; it resembled a para- mecium, although clearly not one. We found no motion whatever, and only this latter substance could be adduced as an absolute proof of anything organised being present. Next day I examined the same liquid; and, whether from the fact of time being given for development or from other causes, there was a very abundant motion. There were at least six specimens in the field at a time, of a body re sembling the euglena, although smaller than I have seen it. When these minute bodies occur it is clear that more may exist, and germs in this early stage are too indefinite to be described. The existence of vital sparks in the organic substances in the air alluded to is all I wish to assert, confirming by a different method the observations of others. It might, of course, be said that since the bottle was opened at Mr. Dancer’s the air at that place may have communicated them. I answer that, before it was opened, a good glass c ould detect floating matter, some of it, however, as in the microscope proved, indefinite enough. Finding this, and fearing that the long time needful to collect liquid from the atmosphere might expose it also to much dust. I used a bottle of about 100 cubic inches dimensions, and putting with it a very little water, not above five cubic centimetres, I pumped out the air of the bottle, allowing the air of the place to enter. This was done six times for each sample, the water shaken each time, and the result examined. This was done with the same bottle that was used in my early experiments with permanganate, and by the same method, except that water instead of that salt was used. At first considerable numbers of moving particles were foimd ; but it was needfnl to examine the water used, and here occurred a difficulty. It was not until we had carefully treated with chemicals, and then distilled the water again and again, that we could trust it. Particles seemed to rise with the vapour, and if so, why not with the evaporating water of impure places. Having kept an assistant at the work for a week, and having myself examined the air of three cow-houses, I came to the con clusion that the air of cow-houses and stables is to be recognized as containing more particles than the air of the street in which my laboratory is, and of the room in which I sit, and that it contains minute bodies, which sometimes move, if not at first, yet after a time, even if the bottle has not been opened in the interval. There is found in reality a considerable mass of debris with hairs or fine fibres, which even the eye, or at least a good pocket lens can detect. After making about two dozen trials, wc have not been able to obtain it otherwise. Even in the quiet office at the laboratory there seemed some indications. I found similar indications in a cow-house with healthy cows; so I do not pretend to have distinguished the poison of cattle plague in these forms ; but it is clear that where these exist there may be room for any ferment or fomites of disease ; and I do not doubt that one class is the poison itself in its earlier stage. It would be interesting to develop it farther. I have recorded elsewhere that I condensed the liquid from the air of a flower garden, and found in it, or imagined I found, the smell of flowers. I do not remember that I looked much to the solid or floating particles, thinking them to be blown from the ground ; but it does not affect the result, whether they may be found constantly in the air, or are raised by the action of currents. Tub Railway Viaduct at Runcorn.—The enormous girder bridge constructed by the London and North-Western Railway Company across the Mersey at Runcorn, in order to shorten by some fifteen miles the route from London to Liverpool, is now so near completion as to be ready for the preliminary tests of its stability. Once and again upon recent occasions, the tests were conducted under the superintendence of Mr. Baker, chief engineer to the company, Mr. F. Stevens, civil engineer, Mr. Wells, resident engineer, Mr. Cochrane, contractor, and Mr. Ashton, local superintendent. The bridge is built on four buttresses, 167 feet in height from their foundation, and has three central spans of 305 feet each. At high water the space from the water level to the bridge is 75 feet, and at low water 95 feet. The test consisted of sixteen engines on each span, which were moved to and fro, at various rates of speed. The total weight would be about 800 tons on each span. The greatest deflection observed was only Ij inch. Some minor works on the new junction line still remain to be finished, but the new route will, it is expected, be opened in the autumn. Statue to Palisst the Potter.—A statue of Bernard Palissy has been executed for the town of Saintes, his birth-place, by M. Taluer, and the inauguration is announced to take place on the second of the coming month of August. Statue to the Late Painter Ingris.—Out of the large number of models sent in for this competition, the Academy of the Beaux Arts of Paris has not judged any one deserving of the first prize, which would carry with it the right to execute the work, but it has awarded the second prize, of 1,000 francs, to M. Maillet; and the third, 600 francs, to MM. Falgniere, sculptor, and Boitte, architect, for their joint production.