KNOWLEDGE & SCIENTIFIC NEWS. 



Sept. 1905. 



The "Tele ©Lctivity'* of 

 ChemicoLl ResLctions. 



Many readers of " Knowledge " will, perhaps, be sjlad 

 to hear of some research which offers an unlimited field 

 for experiments, and which may also prove to be of 

 some importance in several branches of manufacture. 



Resonance in sound is familiar, both in practice and 

 theory, to everyone ; wireless telegraphy is an example 

 of electrical resonance ; in the former, the effects are 

 produced by vibrations in the air ; while, in the latter, 

 the ether is the medium which transmits the disturb- 

 ances. It does not require a very great effort of imagi- 

 nation to conceive that something similar may take 

 place when waves in the ether are produced by means 

 of a chemical reaction. 



With the object of investigating this, several experi- 

 ments have been proposed and carried out, but the re- 

 sults up to the present have not Ijeen very conclusive. 



Two substances (mercury and iodine), which combine 

 readily at ordinary temperatures to produce a com- 

 pound easily recc^nised, were placed together in an 

 open vessel. .V vigorous chemical reaction (sulphuric 

 acid on potassium chlorate and sugar) was allowed to 

 take place very near it, and the mercury and iodine 

 were afterwards compared with a similar mixture which 

 had been prepared at the same time, and kept in another 

 room. The amount of mercuric iodide protluced in the 

 protected vessel was much less than in that which had 

 been exposed to the reaction. It was suggested that 

 the heat produced by the reaction would account for the 

 difference, and so the experiment was repeated with an 

 asbestos mat placed over the vessel to shut off the heat, 

 a thermometer being placed with the mercury. 'Ilie tem- 

 perature did not rise, but the effect was not as marked 

 as before. 



A photographic plate was then exposed to the same 

 reaction fwell protected, of course, from light rays), 

 and when developed the image of lines on a piece of 

 paper could l)e clearly seen. This, perhaps, may be ex- 

 plained in some other way. 



It was then decided to determine whether one reac- 

 tion would accelerate another. Two solutions were 

 prepared containing the same quantities and proportions 

 of sodium thiosulphate and hydrochloric acid. One 

 was removed as before, while the other was exposed to 

 the chlorate reaction. In every case it was ob.serx'ed 

 that sulphur was deposited more quickly in the solution 

 expo-sed to the reaction. These experiments were re- 

 peated, using blank cartridge to produce the disturb- 

 ance, and very decided results were ;i^ain obtained. 



The strengths and proportions of the solutions were 

 varied considerably : — 



H CI I cc. (cone.) in 25 cc. water, to 



I cc. „ in 50 cc. water. 



Na, S, 0» I gr. in 125 cc. water, to 



I gr. in 75 cc. water. 



Proportions taken — 



5, 10, 15 H CI with 20. 25, 50 Naj S^ 0;,. 



-Similar experiments were tried, using hydrogen per- 

 oxide and potassium iodide (with a little starch to .show 

 separation of iodine). The effect of the explosion was 

 always to cause a sudden coloration of the solution, 

 while an exactly similar solution prepared at the same 

 time, but not exposed to the explosion, did not change 

 colour until several minutes later. 



About a week afterwards, these experiments were 

 repeated ; the results observed were similar to. I)ut iim 

 as decisive as, those mentioned above. 



Tlie effect of the explosion of nitrogen iodide on a 

 mixture of hydrochloric acid and sodium thiosulphate 

 solutions, using same strengths as before in propor- 

 tion of 10 to 50 cc, was a scarcely perceptible difference 

 in the rates of deposition. When the proportions were 

 altered to 13 to 50 cc, the difference was very decided. 



The above results were thought to be due to the 

 shaking produced by the explosion, but it was found 

 that there was no difTerence in the rates of deposition of 

 the sulphur, if one were shaken mechanically, and the 

 other not. 



Iioth chemical combination and decomposition have 

 been employed to affect another reaction at a distance, 

 but in all cases the results, when critically examined, 

 were hardly decided enough to warrant the assertion 

 that one chemical reaction can be influenced by anotlier 

 when there is no apparent communication between 

 them, .^n accident, however, showed th;it this was at 

 least possible. A large quantity of the chlorate and 

 sugar mixture had been made up in proportion not 

 noted. A little of this was placed in a basin, and while 

 the rest of the mixture was held behind the operator, in 

 a large mortar, strong sulpiiuric acid was added to the 

 former, causing it to ignite in the usual way. Immedi- 

 ately afterwards, the rest of the mixture blazed up, 

 although it was impossible that sulphuric acid could 

 have got to it. 



Similar mixtures in a great number of different pro- 

 portions have been prepared and tried, but up to the 

 present the exact proportions necessary for a repetition 

 of the above phenomenon have not been ascertained. 



It was thought that the desired result might, perha"s, 

 be obtained if the two mixtures were cornected in 

 some way — by a wire or piece of glass tubing — but 

 these methods have given no results. TIic experi- 

 ments have been tried using similar and dissimilar 

 substances : — Chlorate and sugar on a similar mixture; 

 nitrogen iotiidc on nitrogen iodide; chlorate and sugar 

 on a mixture of these substances, but in different 

 proportions ; chlorate and sugar with nitrogen 

 iodide ; also strong sulphuric acid and water, 

 strong acids and solid caustic soda have been 

 used as primary reactions, molecular proportions 

 always being employed. When solid substances are 

 used, the effects are not obtained, probably because the 

 substances or prf)portions are not "in tunc"; while when 

 liquids are used a certain amount of action is observed, 

 but the greatest possible effects are not produced. 



One other experiment awaits a satisfactory explana- 

 tion : .Some nitrogen iodide had been prepared and 

 kept for nearly a month suspended in a solution of 

 ammonia. The day on which its services were re- 

 quired had been devoted to a large number of ex- 

 perimcnls with potassium chlorate and sugar. The am- 

 inoniacal nitrogen ifxlide solution was carried across 

 the laboratory, with the object of being filtered and 

 dried, and placed on the bench where the above experi- 

 ments had just been carried out. It had only been there 

 five seconds at the most, when it exploded with its 

 customary violence. 



Of course it may be only a coincidence — even then, 

 the object of the investigation is to explain these "coin- 

 cidences" — or it may be that a violent chemical reaction 

 converts the space in its immediate vicinity into a 

 medium that will accelerate or even induce chemical 

 activity. This latter docs not appear an impossible ex- 



