Intelligence and Miscellaneous Articles. 307 



obtained in numbers (free from theoretical objection), and capable of 

 having the probable error computed, it should; be ajdopted until 

 something better can be advanced. 



■ " It will not do for any one to tell the public, even in the case of 

 the magnitudes of stars, that ' he has tried all instrumental methods, 

 and found all to be inferior to estimation by the naked eye ; ' be- 

 cause, so long as such a method of observation is the only one fol- 

 lowed, so long will the assertion remain mere rhetoric, — a consump- 

 tion of time without producing its equivalent of useful effect. Let 

 us rather remember the primary and aphorismal foundations of prac- 

 tical science, such as : — 



*" Science begins with the observation of common facts, but, even 

 ■at this stage, requires that the observations be precise.' 



^*' Facts are the materials of science, but all facts involve ideas, 

 aM' since in observing facts we cannot exclude ideas, we must take 

 care that for the purposes of science, the ideas be clear and vigo- 

 rously applied. Therefore, facts for the purposes of material science, 

 should involve conceptions oi the intellect only, and not emotions, and 

 must be observed with reference to our most exact conceptions, 

 number, place, figure, motion, force, &c.' " 



XLVIII. Intelligence and Miscellaneous Articles. 



ON OXIDATION BY MEANS OF CYANOGEN. 

 BY M. P. C. BOUDAULT. 



THE author observes that chlorine, bromine and iodine are not 

 the only bodies which possess oxidizing power by indirect 

 action ; and he shows that cyandgen, which has been proved to act 

 in many cases as an elementary body, is also susceptible of effecting 

 oxidizement. 



The instability of cyanogen, when dissolved in water, always ap- 

 peared to offer an obstacle to the author's proposed researches on 

 this subject ; it therefore occurred to him to replace cyanogen by a 

 compound, in which this body was in loose combination, or, so to ex- 

 press it, in a mobile condition, that it might readily act upon oxy- 

 genated compounds, and separate their oxygen ; and these condi- 

 tions appeared to be fulfilled by the ferridcyanide of potassium, or 

 red prussiate of potash. This salt, when heated out of the contact 

 of air, is decomposed into nitrogen, cyanogen, ferrocyanide of po- 

 tassium, cyanide of potassium and carburet of iron ; but when de- 

 composed in air it yields peroxide of iron and more cyanogen. It 

 appeared therefore to the author that this compound might yield a 

 portion of its cyanogen by certain acid reactions ; and this was found 

 to be the case. 



When the equivalent of potassium, which chlorine removes from 

 ferrocyanide of potassium to convert it into ferridcyanide, is added to 

 it, no reaction takes place between them, even in a month, at ordi- 

 nary temperatures ; but when boiled and concentrated, peroxide of 

 iron is precipitated, cyanide and ferrocyanide of potassium are 

 formed, but no oxygen is obtained. 



X2 



