r 2S3 J 



LIV. Intclligcftcc arid Miscellaneous Articles. 



LETTER ON MALLEABLE ZINC. 

 SIR, 



X AM induced to request your inserllon of the followini^ 

 notice, iu consequence of having read in your iiiagazine for 

 October*, an account or Messrs. Hobson and SiU-ester's 

 discovery of a method of making zinc ductile or malleable. 

 I do not mean at all to question that the above-named gen- 

 tlemen did really of themselves make the discovery of this 

 property of zinc ; yet, as I am acquainted with one who has 

 a prior claim to the discovferv, I think the public should 

 be informed of the fact, as the reputation of first inventor 

 is often the only reward an ingenious man has for his la- 

 bour. About twenty years ago, Mr. W. E. Sheffield, of 

 Somers Town (an eniinent metallurgist), making an assay 

 of some blende, and being rather impatient to examine the 

 metal, struck an ingot with an intent to break it, while it 

 was yet hot ; but was greatly surprised to find, that instead 

 of being brittle and breaking with tlie usual fracture of zinc, 

 it was extremely tough, and when broken (after many 

 bendings back and forward) exhibited a steel-grained fibrous 

 texture. Doubting whether his metal was only zinc, he 

 repealed thj experiment, and witli some that he knew to 

 be pure, and had the same result ; from wliich he immedi- 

 ately concluded that zinc, at a certain temperature, was 

 probably as malleable as the other metals. 'I'his he found 

 to be the case both in drawing it into wire and laminating 

 it between rollers : specimens of this last, not the COOdi 

 of an inch thick, possessing the strength and tenacity of 

 silver, I had from him for a particular purpose, long before 

 the annunciation of Messrs. Hobson and Silvester's patent- 

 Mr. Sheffield has long been in the habit of furnisiiing the 

 cabinets of his mineralogieal friends, both at home and 

 ■abroad, with a variety of specimens of manufactured and 

 lauiinatcd zinc. 

 £7, TJchfleld-strect, ^ ^m, sir, yours. 



Tec. i'3, 1805. W . Lo^VRY. 



CHEiNIISTEV. 



Mr. Parkes, manufacturing chemist, has for some time 

 past been engaged in preparing an elementary chemical 

 \v<v, k, in a catechetical form, for the use of schools, aiid 

 for the instruction of those persons who are unacquainted 



* Page 93 of the present volume. 



with 



