76 SCIENCE PROGRESS 



He then proceeds to sketch a " theory," but the terms used 

 are those used in the previous articles in this journal. Evidently 

 he has assimilated a good deal since the publication of his first 

 communication to the Chemical Society and will soon be 

 quite an orthodox exponent of electrolytic doctrine. I venture 

 to think, however, that we have long had a satisfactory theory 

 of the corrosion of iron — at all events, our " theory " of the 

 process is certainly not incomplete owing to the lack of 

 experimental facts but because of the general lack of appre- 

 ciation of the facts, owing to the long-continued failure of 

 chemists to take notice of a few fundamental principles. If, 

 moreover, a simple and natural development of the ideas 

 of Faraday will give us the beginnings of a satisfactory theory 

 of corrosion, why, it may be asked, have Mr. Lambert and others 

 been so slow in assimilating them ?— they have simply never 

 made the attempt until persistent hammering at the truth has 

 forced them at last to pay some attention to it. But it is often 

 and well said : better late than never. We may be thankful that 

 some appreciation of the value to chemists of Faraday's teaching 

 is at last being shown. That the tendency should become mani- 

 fest even in a centre of feudalism such as that in which 

 Mr. Lambert works bodes well for the future. Faraday's work 

 was done only about seventy-five years ago, and therefore has 

 not the crusted authority of Greek masterpieces. 



At all events, Mr. Lambert now recognises that the presence 

 of an electrolyte is an essential feature in rusting — he sees that 

 otherwise there can be no change. As he says, "No part of 

 the metal can dissolve unless an electric current actually passes 

 through the electrolyte." Moreover, he implies, if he does not 

 assert, that iron pure and simple, if in contact with a relatively 

 electronegative conductor, will be attacked by water in the 

 entire absence of acid. He speaks of water, however, as 

 the electrolyte water and everything turns on this. 



When he can show that water is an electrolyte, no one will 

 hesitate to agree with him: but he cannot: both the evidence 

 and theory go to show that it would not be, if it were obtain- 

 able. To quote, as almost every one does, Kohlrausch's 

 experiments made many years ago in very ordinary glass as 

 proof that water is an electrolyte is absurd ; Kohlrausch never 

 had water to deal with, and any one who seeks to refine on his 

 experiments would only carry the purification a stage further 



