KEW YORK, OCTOBER 6. 1893. 



CURRENT NOTES ON CHEMISTRY.— m. 



[Edited by Charles Piatt, Ph. D., F. C. -S'.] 

 British Association, Nottingham Meeting. 



The International Scientific Congresses recently lield 

 in Chicago have attracted world-wide attention and have 

 rightly been accepted as the feature of our great "Fair." 

 But other meetings have also been held this summer, sev- 

 eral of rather more than usual interest. At the meeting 

 of the Iron and Steel Institute many valuable papers were 

 presented, and more recently the meeting of the British 

 Association for the Advancement of Science was opened 

 at Nottingham, September 13. For some years past and 

 for no well-founded reason, the meetings of the British 

 Association have been but lightly attended by the pure 

 scientists, but this present year, largely through the 

 labors of Prof. Emerson Reynolds, M. D., Sc. D., F. R. S., 

 President of the Chemical Section, Section B., a larger at- 

 tendance was secured and a superior i^rogramme ob- 

 tained. An attractive feature was the lecture hj M. 

 Moissan, on the preparation and properties of the element 

 fluorine, together with exhibitions and demonstrations 

 of his progress in chemistry and high temperatures. 



Professor Reynolds's opening address before Sec. B. is 

 an epitomized review of the work done during the past 

 year, with special attention to certain features of advance 

 made in our knowledge of chemical theory. Reference is 

 made to the methods of inquiry and study in medicine, 

 and while vast progress is shown during the jsast twenty- 

 five years, the present state of the chemical branch of this 

 instruction is deplored as leading to a knowledge of sub- 

 stances rather than of principles, of products, instead of 

 the broad characters of the chemical changes in which 

 they are formed. Without this higher class of instruc- 

 tion it is unreasonable to expect an intelligent perception 

 of comp)lex physiological and pathological processes which 

 are chemical in character, or much real aj)preciation of 

 modern pharmacological research. 



A side light is being thrown on the nature of the ele- 

 ments by the chemico-physical discussion between Arm- 

 strong and Hartly as to the connection existing in the 

 constitution of certain organic compounds and the colors 

 they exhibit. We may take it as an established fact that 

 a relation exists; and, if so, then why may not elements of 

 distinct and characteristic color be considered as com- 

 plexes analogous to definitely decomposable substances? 

 The two elements, nickel and cobalt, of decided color in 

 their salts and in their metallic plates, add strength to 

 this idea in that they may be considered as exhibiting a 

 sort of isomerism. Their atomic weights are the same 

 within limits of experimental error; and, by analogy with 

 compounds, identity of atomic weight implies dissimilar- 

 ity in constitution and therefore definite structure. 



The genesis of chemical elements is now being studied 

 with the application of the principles of gravitation. Men- 

 deleef, in 1889, first proposed to apply Newton's Third 

 Law, and now Rev. Dr. Houghton in recently jsublished 

 papers applies the three Newtonian laws to explain the 



interactions of chemical molecules, with this difference 

 only, that atoms have a specific coeflScient of attraction 

 varying with the nature of the atom concerned, whereas 

 the specific coefficient of gravity is the same for all bodies 

 independent of their composition or matter. 



The remainder of Dr. Emerson's jjaper is devoted to a 

 sketch of comparative chemistry, of great interest but 

 rather difiicult of condensation. Silicon is considered as 

 an analogue of carbon. Nitrogen compounds of silicon 

 are prepared and described, but it is shown that the com- 

 bination is not a natural one and that, as silicon dissolves 

 freely in molten aluminum, so in nature it is with alum- 

 inum that it most readily combines. Aluminum may 

 then be considered, in this respect at least, as analogous 

 to nitrogen. The natural alumino-silicates are, according 

 to this standpoint^ products of the final oxidation of some- 

 time active silico-aluminum, analogues of carbo-nitrogen 

 compounds rather than ordinary double salts. The 

 alumino-silicates of the primary rocks are thus oxidized 

 representatives of substances which foreshadowed in 

 terms of silicon, aluminum and oxygen, the compounds of 

 carbon, nitrogen and hydrogen requii-ed at a later date of 

 the earth's history for living organisms. 



Production OF Pure Oxygen From Air and Furnace Gases. 



A NUMBER of processes for the manufacture of pure 

 oxygen from air have appeared recently, all following in 

 a general way the suggestions of the well-known "Bria" 

 process. Herr G. Kassner in the Chemiker Zeitung, claims 

 a superiority for a salt of calcium, the calcium plumbate, 

 Ca^PhO^, his process being briefly as follows: The 

 plumbate in spongy porous pieces is exposed to the action 

 of moist furnace gases which have jareviously been 

 well washed. Carbonic acid is absorbed by the calcium 

 salt with decomposition, forming calcium carbonate and 

 free peroxide of lead. This decomjiosition is unaccom- 

 panied by a change of form. The resulting mass is trans- 

 ferred to a strong retort heated to redness. Oxygen is 

 disengaged and the evolution facilitated by a stream of 

 superheated steam. Finally carbonic acid is given off and 

 in the last stages this is pure. In the intermediate stage 

 the gases are joassed over calcium jilumbate and the car- 

 bonic acid there absorbed leaving the oxygen pure. 

 Another similar process has been patented by Peitz, cal- 

 ling for the use of pure carbonic acid. 



Le Chatelier proposes a direct method of heating to 

 drive off the oxygen and a reabsorption of the oxygen 

 from the air, but Kassner, who has already exjDerimented 

 with the direct method, considers the higher temperature, 

 the larger expenditure for fuel necessary, and the conse- 

 quent greater wear uj)on the retorts, serious obstacles suc- 

 cessfully overcome only by his later indirect method. 



Mr. L. Chapman, London, has patented a process de- 

 pending upon the alternate oxidation and reduction of a 

 mixture of manganese dioxide ("or a similar substance") 

 with caustic soda by means of air and steam respectively. 

 Finely divided manganese dioxide and caustic soda in the 

 proportions necessary to the formation of the manganate 

 are mixed with a weight of sodium sulphate equal to the 

 weight of caustic soda taken. Air is jiassed through 

 small pipes leading nearly to the bottom of the vessel. 



