ON BLENDS. 33>T 



The improvement of this simple instrument has cost Mr. 

 Hardie much time, and even expense ; and he will be glad 

 to receive any remuneration from the Society which they 

 may think his invention deserves. 



I am. Sir, 

 Your most humble Servant, 



A. TILLOCH. 

 To C. Taylor, M. D. 



Twenty-three persons testified by their signatures and 

 subscriptions to Mr. Hardie their approbation of his Cut- 

 ting Press. 



Reference to the Engravings of Mr. J. Hardte's Boole- 

 binder's Cutting Press. Plate X. Fig. 5. 

 The principal difference between this and the press which Description of 

 has been from time immemorial employed by the book- 

 binders consists in effecting the business by one iron 

 screw, instead of two wooden ones formerly used. This 

 screw works in a nut let into and screwed to the top 

 piece A, its lower end working in a collar, screwed to the 

 moving piece B, sliding in grooves within the two sides of 

 the frame. C C are the guides for the plough, as in the 

 common press. 



VI. 



On Blende, and some other Articles; by Professor Proust*. 



JL HAT zinc is incapable of disputing oxigen with eharcoal, The zinc in 

 is a known fact: and the same maybe said of sulphur. ox ^ e ? n ° tan 

 Consequently, if blende contain oxigen, it must yield it to 

 the action of charcoal. 



I kept a mixture of transparent yellow blende and fir 

 charcoal at a red heat for an hour, but I did not find the 

 slightest indication of sulphurous acid. The mixture being 

 washed, to separate the charcoal, left the blende behind, 

 which had undergone no change. Where then is the 

 exigen of blendes? 



* Journal de Physique, Vol. LXIV. p» 150, Feb. 1807. 



I have 



