538 Prof. H. E. Armstrong. Enzyme Action as hearing [Apr. 5, 



and chlorine ions are present to the extent of 70 odd per cent. I 

 have ventured to characterise such an assumption as not merely 

 unnecessary but eminently improbable : the contradictions involved in 

 the conception being extraordinary — for while we are asked to believe 

 this of hydrogen chloride, we are assured that a substance of such very 

 inferior stability as mercuric chloride exists in solution practically 

 " unionised." There is danger that under the guidance of mathe- 

 maticians anxious to negotiate numerical agreements, we may lose our 

 sense of proportion as chemists ; I believe the danger to be a very 

 serious one, against which it is necessary to make some protest. We 

 shall fail in securing the object we aim at if we allow the element of 

 authority to intrude in any way into our work : it will cease to be 

 scientific ; it will be impossible to claim for it any special educational 

 value ; an attitude of doubt rather than one of conscious certainty is 

 essential to progress. 



Although the solvent is now regarded as of importance, its peculiar 

 importance and functions are far from being sufficiently recognised. It 

 is necessary, in fact, to urge that the nature of the correlated processes 

 of electrolysis and chemical change need to be considered most care- 

 fully, from every point of view, especially- with reference to the func- 

 tions of the solvent and the part played by residual affinity. Eesults 

 such as have been obtained by Brereton Baker — proving that inter- 

 actions occur only when a somewhat complex conducting circuit is 

 established — must be fully taken into account : the observations of this 

 chemist on the formation of ammonium chloride, for example, are of 

 the utmost consequence; yet the advocates of the ionic hypotheses 

 simply disregard all such evidence. 



In my paper presented to the Society in 1885, I contended that the 

 special influence exercised by water is to be attributed to the residual 

 affinity possessed by the oxygen atom of the water molecule ; this 

 view has gradually grown in popularity of late years in consequence 

 of the discovery by Collie and Tickle, von Baeyer and others of com- 

 pounds in which oxygen apparently functions as a tetrad. There has 

 naturally been a tendency to extend the view to other elements and to 

 attribute the "ionising" power of liquid ammonia, hydrogen cyanide, 

 etc., to residual affinity. But it is necessary to be cautious in 

 accepting the conclusion that these solvents are strictly comparable 

 with water. Water is perhaps peculiar in the extent to which it con- 

 ditions the electrolysis of substances which are not electrolytes per se. 

 In at least a large proportion of the cases in which conducting solutions 

 in solvents other than water have been obtained, substances have been 

 used which are conductors per se in the liquid (fused) state : it may be, 

 therefore, that the conductivity of such solutions is but a consequence 

 of the presence of the liquid substances and is largely if not wholly 

 independent of the solvent, the relatively high conductivity of some of 



