334 On tlie. Affinity existing let ween 



plant for the ensuing year. This operation is called ravalle- 

 tnenty and is very different from the pruning practised in the 

 department of the Mame. 



An intelligent proprietor, who has a large extent of vine- 

 yard, should bury some vines (ravaller) every year, in order 

 to have a sure and constant supply of plants for replanting. 



The methods of treatment are in every respect the same 

 with high and low plants. 



XL. On the Affinity existing between Oxides of Carbon and 

 Iron. By David Mushet, Esq. 



In my late communications to the Philosophical Magazine, 

 a number of experiments were adduced to exhibit the uni- 

 versal diffusion of carbon, and to convey a tolerably correct 

 idea in what proportions it enters into the composition of 

 animal, mineral, and vegetable substances. 



The affinity that exists mutually betwixt iron and carbon is 

 every day manifested as the basis of one of our greatest na- 

 tional manufactures : in particular, in the various modifi- 

 cations of cast iron, steel, plumbago, &c. 



Any inquiry that has for its object the investigation of 

 jhose means, and of their peculiar modes of formation, to 

 which we exclusively owe the exisience of the most widely 

 diffused and most useful metal that has hitherto been known 

 in civilized society, commands attention, not only as a 

 matter of curiosity, but as an object of die highest impor- 

 tance. 



The natural mutual affinity of iron and carbon is such, 

 that they may be reciprocally used as tests and agents of 

 each others existence respectively ; and upon this principle, 

 chiefly, the experiments which are to follow were performed. 



The first object to be ascertained, in pursuing this investi- 

 gation, was the nature of oxide of carbon, whether in the 

 State of charcoal, coke, plumbago, &c. ; and wherein, and 

 jn what, it differed from the matter of carbon that existed 

 naturally in the substances from which these were obtained. 



If any two oxides of carbon were taken similarly com- 

 pounded 



