of Weights and Measures. 247 



of most effectually obviating such malpractices in future. I 

 take this opportunity to ex'iress my entire concurrence with 

 the two clauses in the Act for altering of the present weio-hts 

 and measures, which require that tables of equalization and 

 conversion from the quantities and values of present mea- 

 sures to that of the imperial measure, shall be prepared and 

 .published. 



I was so thoroughly convinced of the necessity of tliis, that 

 I actually prepared tables of equalization and conversion, as to 

 quantity and value, from all the midtifarious measures in the 

 British empire to that of the imperial staridard. And as the 

 Act is put oft" until next Session, I mean then to be also pre- 

 pared with similar tables to convert from aW foreign standards 

 to the same standard ; thoroughly convinced that, if I am any 

 way seconded in my eftbrts, I shall be enabled to give to the 

 world one of the greatest advantages, in a commercial point of 

 view, which has ever been submitted to the public. And as I 

 doubt not that truth and equity are the prominent character- 

 istics of your publication, and that you will readily admit tlie 

 necessity of accuracy, in a great commercial nation like ours, 

 in matters involving the best interests of thousands of its in- 

 habitants, I am persuaded that you will permit me to endea- 

 vour, in your next, to obviate the evils of which I complain. 

 I have the honour to be, gentlemeii, 



Your most obedient humble servant, 



Wm. Gutteridge. 



XLV. On an Improvement in the Apparatus for procuring 

 Potassium. By William Mandell, B.D. Fcllorc ofQiieen's 

 College.* 



\_In repeating the late Professor Tennant's experiment for 

 procuring poUissiumf, (which difters from the similar one first 

 made by the French chemists, Gay-Lussac and Thcnard:]:, 

 principally in being more simple and commodious for prac- 

 tice,) it occurred to me, that one part of the ajjparatus made 

 use of, might, with advantage, be still further simplified : and 

 as every circumstance, however apparently obvious or trivial 

 in itselij which, in any degree, tends to facilitate the produc- 

 tion, in greater quantity, of so powerful a chemical agent as 

 potassium, is of importance, I have thought that the mode of 



• From the Cambridge Philosophical Transactions for 1822, Part II, 

 f Philosophical Transactions for 1S14, p. r>7H, to which the render is re- 

 ferred for the detail of the process. See l^hil. Maj;. vol. xliii. 457. 

 \ Aiiiialrs dc Cliimic, torn. Ixvi. p. 205. 



operating 



