xxm 



or as President, which last position he filled from July, 1883, to July, 

 1884. To the meetings of this Society he contributed many im- 

 portant papers, all bearing on the industry which he had made his 

 special study, and some of them — notably that " On the Present 

 Position of the Soda Industry " (8th January, 1883) ; his Presidential 

 Address (9th July, 1884) ; and that on " The Proposal to Raise a 

 Memorial to Nicolas Leblanc " (5th March, 1885) — of such literary as 

 well as intrinsic merit as to create a deep and lasting impression on 

 those who heard or read them. 



It may truly be said of Mr. Weldon that he was always working 

 and always learning. Every hour spent in travel, every hour that 

 could be snatched from actual pen- work (for, until the last three 

 years of his life, he did nearly the whole of the vast correspondence 

 incidental to his position with his own hand, often spending some 

 ten hours a day in sheer writing) was devoted to the planning or 

 studying out of new chemical processes or improvements on old 

 methods. From the earliest years of his chemical work, as has been 

 shown above, he had cherished and laboured at the idea of a cheap 

 and practicable magnesia-chlorine process ; and he was now to have 

 the satisfaction of arriving at a solution of the problem from a 

 chemical point of view, and also of seeing the mechanical difficulties 

 of such a method in a fair way to be mastered by the engineering- 

 skill of his close friend and collaborateur, Monsieur Pechiney. This 

 new chlorine process — which its inventor confidently expected to 

 produce as great a revolution in the alkali trade as had resulted from 

 the adoption of his lime-manganese process twenty years ago — was 

 fully described by Mr. Weldon in his memorable address to the 

 Society of Chemical Industry, at Newcastle, on the completion of his 

 Presidential year, in July, 1884 ; and again in the Journal of that 

 Society for September, 1885. It may be briefly described as follows : 

 Solution of chloride of magnesium— obtained either by the neutra- 

 lization of hydrochloric acid by magnesia, or by decomposing the 

 residual ammonium chloride of the ammonia- soda process by mag- 

 nesia ; or as the Stassfurt native salt — is evaporated down to a 

 certain point. Sufficient magnesia is then added to produce a solid 

 mass containing about six equivalents of water. This mass is further 

 dried and is then crushed into morsels of about the size of a 

 walnut, which morsels are subjected to a current of air in a special 

 furnace, invented by M. Pechiney, the result being that nearly the 

 whole of the chlorine present is evolved, partly in the free state and 

 partly as hydrochloric acid. The process has been in regular opera- 

 tion at the works of Messrs. A. R. Pechiney et Cie., Salindres, since 

 July, 1887, with highly satisfactory results. 



Mr. Weldon was well known as a regular attendant at the meetings 

 of the British Association, and as a frequent contributor of papers to 



