Bauxite is an ore of great importance in certain industries. For example, when it is fused in a special electric furnace, crystals of aluminium oxide are formed which are extremely hard, the diamond being only slightly harder. This is known under the registered trade name as Alundum. Alundum, besides being used for the well-known abrasive wheels for grinding and finishing materials in the course of manufacture, is used in another form for stair treads, as for example on tramway cars, or in railway stations. It is used also for danger places. in factories where slipping must be prevented. It is quite acid resisting, and can be used in chemical works' floors. Clay is used as a binder to form the alundum tiles, wheels, etc. New Patents. THIS list is specially compiled for The Chemical News, by Messrs. Rayner & Co., Registered Patent Agents, of 5. Chancery Lane, London, from whom all information relating to Patents, Trade Marks, and Designs can be obtained gratuitously. Latest Patent Applications. 20385-Gaillard, E. A.-Manufacture of sulphuric acid. Aug. 10. 20132-Jucker & Co., Chemische Fabrik.-Recovering chromic salts from residues. Aug. 7. Specifications Published this Week. 201231-Merrill Co.-Process of precipitating metals from solutions. 201302-Farbwerke vorm. Meister, Lucius & Bruning.-Manufacture of a complex aminoargentomercaptobenzene-carboxylic acid. 185728-Etablissements Poulene Freres.-Process for the commercial preparation of aminophenyl-arsenic acids and of their derivatives. 201488-Vains, A. R. D.-Continuous chlorination of ligno and pectro-cellulose by nascent chlorine for the purpose of obtaining pure cellulose. 197932 Pereira, H.-Process for manufacturing a dye from dioxyperylene. Abstract Published this Week. 199154 Isatine arylides, Stephan C., of Altona, Germany. the Isatine-...-arylides are isolated from their solutions in sulphuric acid as sulphurous acid compounds by treatment with ammonium sulphite or bisulphite in quantity corresponding with whole sulphuric acid content; preferably the sulphuric acid solution is introduced into the sulphite solution in the form of a spray. Ammonium sulphate is recovered as a bye-product, and the escaping sulphur dioxide is absorbed in ammonia to produce sulphite again. Examples are given in which the reaction product (containing isatine anilide) of example III. of Specification 15497/99 is allowed to react with solutions of ammonium sulphite or bisulphite, the isatine anilide sulphurous acid compound being precipitated. Messrs. Rayner & Co. will obtain printed copies of the published specifications and abstract only, and forward on post free for the price of 1s. 6d. each. Examinations which are also catered for by the Course include: B.Sc. (Lond.) Ext. Associate, Institute of Chemistry. A number of Part-time Courses are also available to cover requirements of Work's Chemist, and those of various public examinations. OPEN SCHOLARSHIPS, covering tuition fees and maintenance grants of £40 per annum for three years, are offered for competition annually, and candidates for entry to the above Department are eligible to compete. For further particulars of Full-time and Part-time Courses, Entrance Examination, Scholarships, Fees, etc., apply to the Principal. Forms of application for admission to the Entrance Scholarship Examination, duly completed, must be received by the 17th September. JOHN J. JACKSON, THE CHEMICAL NEWS, VOL. CXXVII. No. 3308. THE QUANTUM THEORY. BY R. F. HUNTER, F.C.S. In a recent lecture delivered before the Chemical Society of the Royal College of Science, entitled: Some Aspects of the Quantum Theory," Dr. C. K. Ingold, D.Sc., F.I.C., remarked that the quantum theory is less an attempt to explain than a focussing of all difficulties into one. This is very true, and it might be of some interest to us as chemists to consider, firstly, the nature of the quantum theory, and, secondly, its application in Chemistry; for the theory, though now regarded as a destined branch of Physical Chemistry, or rather Chemical Physics, is one of considerable importance to us as chemists, mainly because of its close connection, or rather interdependence with the Bohr theory of the atom, and we fear has been too long regarded in the light of a piece of mathematical physics, and its application in chemistry as being almost of the nature of trespassing of chemists in a field which is one of the of mathematical most sacred domains physics, almost as sacred as that of the theory of relativity. There would appear, therefore, no necessity to apologise for a brief elementary, and, as far as can be nonmathematical review such as this, in a chemical journal. It will of course first be necessary to run over briefly in a rough way, some of the considerations of mathematical physics, such as the question of statistical mechanics. ENTROPY & THERMODYNAMIC PROBABILITY, ETC. If we have Na molecules of hydrogen in a given space v and Np of oxygen in a space v Then it can be shown that if we require 2 molecules of hydrogen to combine with one of oxygen, the chance of this occurrence is given by the expression : 2 Na Np Na + Np will obviously be where R is a constant and C, and Cp the concentrations. The above is a simple application of the S = S = Cv. log TR log v + K We now come to the question of equipartition of energy: We consider a molecule of gas to have, firstly, energy of translation; secondly, energy of vibrations; and thirdly, energy of rotation. The molecular rotations being ascribed to collisions with other molecules, and quite distinguished from atomic vibrations. Instead of molecular rotation might have precessional vibrations. Now, in the case of diatomic molecules, we have three degrees of freedom due to translation, one in respect to linear, and two in respect to molecular rotation: six in all. we Regarding rotation as impossible and substituting precessional vibrations corresponding to degrees of freedom, again we have six in all. Now This would lead us to consider that of the total energy will be for wave length > and between Lts. of 2A, & A.. Hence we should conclude that the number of degrees of freedom of ether is not by any means infinite, and is insufficient to yield an expression which would involve conception of equipartition principle, which would agree with experimental results. To clear matters at this point, Plank put forward his quantum hypothesis of quanta, disregarding entirely the equipartition principle. He assumed that changes of energy between matter and ether cannot be continuous, but must take place in definite steps which are multiples of some small energy unit, the energy considered being a finite function of the vibration frequency concerned. It is of interest to note at this point that Sir J. J. Thomson considered radiant energy units or "quantum" as a region of periodic disturbance travelling along a Faraday tube. Plank laid stress on mode of absorption and of emission of radiant energy by matter. The energy radiated by one element of a black body, for instance, is partially absorbed by the elements. Each of these vibrators or resonators which constitute |