its Atomic Weight and Specific Heat. 39 



was then fused under common salt in a lime crucible ; this 

 precaution was taken in order to avoid contact with siliceous 

 compounds. Considerable loss occurred in this operation ; 

 but I succeeded in obtaining a small coherent mass of metallic 

 glucinum, which latter was found to agree in characters with 

 the metal described by Deb ray*, though that distinguished 

 chemist effected the reduction of his metal in a different 

 manner. 



If we admit, with Awdejew and with Debray, the number 

 4*6 to be the equivalent of glucinum (H=l), the question 

 remains whether the atomic weight, so called, is a multiple of 

 the equivalent by 2 or 3. 



If, as some assert, the atomic weight is 4*6 x 3 = 13*8, the 

 only known oxide of glucinum must resemble alumina. If, 

 on the other hand, the atomic weight is 4*6 x 2 = 9*2, glucina 

 must be an oxide like that of zinc or of magnesium. Each 

 view has received the support of a group of chemists of the 

 highest eminence ; but, owing to peculiar difficulties surround- 

 ing the case, an appeal to chemical criteria has hitherto been 

 insufficient to decide between the two conflicting opinions — a 

 determination of the specific heat of the metal, or of the 

 vapour-density of one of its compounds of simple constitution, 

 being necessary for the final settlement of the question. Of 

 these methods I chose the former ; and having made several 

 determinations of the capacity for heat of metallic glucinum, 

 I have the gratification to state that the data obtained lead to 

 the conclusion that the atomic weight of glucinum is double 

 the equivalent weight. Grlucinum is therefore a diatomic metal 

 with an atomic weight of 9*2 — though, I may add, this num= 

 ber may be slightly affected by a new determination of the 

 equivalent, in which I am engaged. 



The method pursued in making the necessary determina- 

 tions upon which to found the conclusion just stated was 

 devised for the purpose of this inquiry ; and as it is essentially 

 different from any with which I am acquainted, I may be per- 

 mitted to indicate very briefly the plan adopted after a good 

 deal of preliminary investigation! . 



* Annates de Chimie et de Physique, troisieme serie, torn. xliv. p. 5 (1855). 



t, The preparation of pure metallic glucinum in quantities exceeding 

 two or three grammes is difficult and costly. For this amongst other reasons 

 I determined to employ Bunsen's admirable and theoretically perfect ice- 

 calorimeter in the estimation of the specific heat of the metal, as small 

 quantities of material only are required. It proved, however, to be impos- 

 sible, owing to various engagements, to prepare the glucinum in a state of 

 sufficient purity until the season had passed when Bunsen's ice-calorimeter 

 can be conveniently used. I had therefore to devise a calorimetric me- 

 thod which could be employed during the warm weather, and which could 



