242 Messrs. F. C. Calvert and R. Johnson on Alloys. 

 sition, as some of tliem have tlie following constitution : — 



1 equivalent of copper, 

 48 equivalents of tin, 

 or 



98 equivalents of copper, 



1 equivalent of tin. 



Our object was not to examine a few isolated cases, or only 

 the alloys existing in commerce, but to produce a great variety 

 of new alloys, in definite proportions, and to examine their phy- 

 sical and chemical properties, &c. 



The first class of alloys which we shall describe is not only 

 quite new but highly interesting, as being the first alloys which 

 have been prepared with iron in definite proportions. It is cer- 

 tainly remarkable, considering the low price of iron, that no 

 efforts have been made to alloy this useful and cheap metal with 

 those of a more expensive natvirc, such as alloys of iron and tin, 

 or iron and copper, &c., which, if effected, would have given to 

 commerce cheaper alloys than those now in use. 



Our primary object in preparing the following alloys of iron, 

 was to render this metal less oxidizable by alloying it with a more 

 electro-positive metal than itself. We were convinced that if we 

 effected this, it would be the most practical method of obtaining 

 the long-looked for object of diminishing the injury which that 

 valuable metal sustains by exposure to the atmosphere ; but we 

 were deceived in our anticipations, for the affinity of iron for 

 oxygen is such that it is not diminished, except in one case, 

 when combined with potassium or aluminium. 



Alloys of Iron and Potassium. 



The first trial we made consisted in heating to a very high 

 temperature some bitartrate of potash and iron, mixed with ex- 

 cess of bitartrate of potash ; the result was only a melted mass 

 of carbonate of potash, with a button of cast iron, no doubt 

 owing to the fact that the iron, being in a state of minute divi- 

 sion, united first with carbon, and then was unable to unite with 

 potassium. 



We then made a mixture of fine iron filings and bitartrate of 

 potash in the following proportions : — 



12 equivs. of iron . . . 336 grs. or 3 equivs. of iron, 

 8 equivs. bitartrate of potash, 1504 ... 2 ... potassium; 



with a view to produce an alloy having the • composition of the 

 sesquioxide, and submitted the mixture to a high temperature 

 in a crucible, aiid obtained a large button, which was found on 

 analysis to be composed as follows : — 



