cations of clouds. Electrical condition of at mosphere. Thickly clouded at neutral Gloomy, overcast neutral sky. General Remarks. Scarlatina, in a mild form, is somewhat prevalent. Hazy upwards, with neutral Cynanche tonsillaris, frequent little fine rain at times. Thickly clouded. among children and young persons neutral Veil of cloud rapid-positive The blue sky, with ly dispersing, has sud denly a here and there a risen from N.E. electroscopes diverge freely. modification of cumulus. Fine, with various positive Slight divergence at times, clouds. during morning only, -distant lightning at eve. neutral Blue sky, with mo positive Free divergence until sunset. difications of cir rus. 63 29-65 breezes, Clear sky, and fea- neutral S. by W. has varied to S. E. by E. breezes, 2 p.m. 66 29-40 S. by W. 4 p.m. 6, 10 p.m. 6, 25 p.m. 8 a.m. thery cirri. positive Free and continuous electric current. Blue sky, with cir- positive Free divergence. rose fibres dis persed abroad. The cirrose fibres have gradually re solved into cirro Various modifica- neutral tions of cumulus. All divergence has ceased. Thunder approach- negative Continuous discharge of sparks. ing. Storm-cloud passing positive Energy of electric current de rapidly over; -a moderate shower. Heavy rains before sunrise. Cumulo stratus and neutral distant nimbus. creasing. 2,30 p.m. 67 29.45 slightly Nimbus flying has-negative Free divergence when a nim evening abated tily over. bus reaches zenith of apparatus. decreased Numerous modifica- positive Slight divergence steadily. to a smart tions of cirrus. breeze Blue sky with cirro neutral Sensation of langour and opcumulus, &c. sional breeze Gentle rains. variable. pression, with pungent heat of the soles of the feet. The average condition of the atmosphere in this locality has been apparently highly favourable to health, throughout the month. Cases of scarlatina, cynanche, &c., which commenced about the 9th inst., assumed a mild form, and readily yielded to the usual treatment. The various ramifications of cirri, and occasionally the several modifications of cirro-cumulus, have, especially in the fine evenings, presented several highly-beautiful pieces of sky, in which it was obvious that the great agent of the universe, electricity, was performing an active part. During the nights of the 7th, 14th, 18th, 19th, 27th, and 30th, many small lucid meteors made their appearance, passing mostly at or near to a right angle with the magnetic meridian. On Professor Pfaff's Theory of Galvanism. In a Letter to Professor Palmstedt, of Gottenburg, from Professor J. BERZELIUS, of Stockholm. Dated October 9th, 1841.* Dear Friend, I suppose that I, in my last letter to you, forgot to mention a remarkable scientific notice which I received by a letter from Professor Pfaff, of Kiel. You are aware that he has for a long time been engaged in the attempt of deciding the question, whether the contact of the metals, or the chemical effect of the liquor, be the primary action in developing the electricity of the pile. He has invented a hydro-electric pile, in which the metals are not affected by the liquor, and where no apparent chemical decomposition into its component parts is taking place, even when the phenomena of electricity are from 30 to 40 times more intense than by a pile, of equal magnitude and form, of copper, zinc, and diluted sulphuric acid. Fig. 8, plate 1, represents a horizontal section of this pile; where a is, an open cylinder of china covered with platinum, like those of the many a year ago used tea-pots; b is a cylinder of burned, porous, unglazed china, furnished with a bottom; c a cylinder of amalgamated zinc, open throughout; and d a cylindrical vessel of glazed china, or of glass. Into b concentrated nitric acid is to be poured, and into d a saturated solution of sulphate of zinc, which will here have a stronger effect than sulphuric acid diluted with one-tenth of water. The combination of the different pairs is made like that of Professor Bunson. The action was found to be continuous up to 48 hours, when he wrote to me, and no gas had issued from the surface of the zinc, nor had any oxydated zinc been precipitated in the liquor. He considered this phenomenon as an experimentum crusis, proving the theory of electrical contact, and he supposes that this construction of the pile may be of practical use, if the electro-magnetism is to be turned to advantage as a motive force. As to this new electrical instrument, Professor Pfaff may be mistaken in his assertion that a chemical decomposition is not taking place; because, according to all theories, it will follow, but by different phenomena from those which take place when the zinc is exposed to a free acid. A zinc salt will arise on the metal, and, corresponding to the oxyde of the zinc, will be collected in the nitric acid; which, probably, will at length contain a great deal of nitrate of ammonia and nitrate of zinc; and the experiment will then only show that no greater corrosion of the zinc is taking place than what will be equal to the electric current. Concerning the theoretical value of this pile, it would decide nothing, even if the question had not been decided a long time before by Professors Poggendorff and Fechner's Researches. Those This letter was kindly handed to us by Richard Roberts, Esq., C. E., of Manchester, who had it direct from Professor Palmstedt.-EDIT. who attempt to decide it in the hydro-electrical way, will for ever be in a dispute, without coming to a final satisfactory conclusion; because the electrical current and chemical decomposition will always be found quite inseparable. It is alone by the dry way that an experimentum crusis is to be obtained, and will be obtained, in spite of the capricious phenomena of oxydation which have been ascribed to the dry way. The dry electric piles that I brought home in 1819, and which then were many years old, are still, after a lapse of twenty years that I have had them, as powerful as when I first got them. The metals which form them are leaves of tin and brass, so thin as scarcely to be measured; yet these have produced an electric action for twenty-two years, and instead of being oxydized You see, therefore, that this through, are still perfectly metallic. scientific dispute is thus carried on; that some of the persons interested in it do not lay their questions quite impartially to nature. How is it? They are looking continually for arguments in favour of an hypothesis which they consider to be the right one. They will always be found in a situation very disagreeable to the true lovers of science, not being able to be fully persuaded to the facts of the contrary party, pleading to hypothesis instead of refutations by real facts. The former party will be placed without the limits of facts, and thus they will always shew an apparent irrefragibility, although they cannot disprove the facts on the other side of the question. This question will never be ended until the last champion of the wrong supposition has ended his earthly career; then truth will remain triumphant and uncontested. Please to excuse me if I have too long detained you by presenting my own views on Professor Pfaff's experiment. Your friend, JACOB BERZELIUS. "The Experimental and Theoretical Researches in Electricity, Magnetism, &c. By WILLIAM STURGEON; prior to his establishing Annals of Electricity, &c." After leaving the service of the Royal Artillery, in 1820, and as my slender finances presented opportunities, I turned my attention to experimental inquiries, and to the construction of some of those philosophical apparatus which, from boyhood, I had been an admirer of, but of which, during my services at least, a military profession precluded all further knowledge than that which was to be learned from books of science, a species of commodity, at that time, exceedingly rare in the army, even in the distinguished branch to which I belonged. The first piece of my apparatus which found its way into a scientific journal, was a modification of Ampere's rotating cylinders, as improved by Mr. Marsh. This apparatus was disposed of to Mr. Jones, optician, Holborn, who sent it to the United States. Mr. Jones was kind enough to draw up the following short account of it, and got it introduced to the pages of the Philosophical Magazine for September, 1823:-"The apparatus consists of two F |