Proceedings of the P olytechnic Association. 801 



decomposed by carbonic acid ; the resulting acetic acid immediately 

 acts on another portion of the oxyd and is again set free ; thus a 

 small portion of acetic acid is used over and over as the medium for 

 dissolving the oxyd. The white lead made by this, as well as by the 

 old Dutch process, contains an excess of hydrated oxyd of lead. 



Sodium Salts Formed Sy^'theticallt. 

 Mr. A. R. Cotton gave, before >the British Association for the 

 Advancement of Science, the results of his experiments by which he 

 succeeded in obtaining from 100 grammes of sodium 1T5 grammes of 

 sodium salts of acids. His conclusions were : 1. That where a cur- 

 rent of dry carbonic acid is kept constantly passing through absolute 

 alcohol, which is in contact with sodium amalgam containing about 

 two per cent of sodium, for every 150 grammes of sodium used in the 

 reaction, at least 175 grammes of sodium salts, formed synthetically, 

 are produced ; about thirty -five grammes of which are sodium salts 

 of volatile acids, and the remaining 140 grammes are the sodium salts 

 of fixed acids. 2. That the volatile acids do not consist entirely of 

 formic acid, but contain at least one acid of higher molecular weight. 

 3. That the fixed acids are principally acids having a greater atomicity 

 than basicity, and they were originally produced as sodium salts, in 

 which both the basic and typical hydrogen of the acid are replaced by 

 sodium. At the conclusion of the paper, Prof. Frankland said Mr. 

 Cotton, in this preliminary report, had shown conclusively that he 

 had obtained a great quantity of the crude synthetical product, and 

 the great problem now remained of isolating and determining the 

 precise nature of the substances of which it is composed. Should he 

 succeed in solving this problem, the result would be one of the most 

 interesting discoveries in synthetical chemistry. Mr. Cotton had, no 

 doubt, struck out a novel line of research in a class of investigations 

 which at the present time prominently occupied the attention of 

 chemists. 



BUFFEES FOR ShIP CaBLES. 



Mr. E. Saunders lately described before the London Institution of 

 Naval Architects his mode of applying portable bufters or springs to 

 the cables of ships riding at anchor. In principle it is the same as 

 that now applied to railway cars to control the sudden stopping and 

 starting of trains. Mr. Saunders uses India rubber springs of great 

 strength and power, say from twenty to eighty tons, suited to all 



[Inst.] 51 



