1880.] On the Essential Properties, fyc, of Beryllium, 41 



The equivalent of beryllium has hitherto been determined by — 



Berzelius = 4*9 (analysis of the sulphate). 



Awdeeff =\tll / /' • n" m t 



L 4 93 (analysis ot the chloride). 



Weeren „ . . = 4 - 62 (analysis of the sulphate). 



Klatzo = 4-59 „ ,, „ 



Debray = 4*61 — 4" 71 (analysis of the oxalate). 



Nilson and Pettersson = 4*552 (analysis of the sulphate). 



All these numbers are higher than4"0, and consequently the atomic 

 weight of beryllium, if trivalent, must be 13*65, consequently higher 

 than that of carbon. The before-mentioned supposition is conse- 

 quently proved to be unfounded. 



Mr. Lothar Meyer further observes that the atomic heat of the 

 oxygen in beryllia, if a sesquioxide, would be less than in any other 

 oxide known. In the next paper we give the whole series of our 

 determinations of the molecular heats of the rare earths and their 

 sulphates. From this survey, which shows that beryllia, with regard 

 to heat and volume, occupies its proper place at the head of the 

 sesquioxides, we here only extract a few determinations.* If c signifies 

 the specific heat, — 



Atom, heat 

 of oxygen. 



In Be 2 3 c= 75*32 . 02471 =18-61 

 Be 2 o= 27*32 . 0*4246=11*60 



7*01 = 3. 2*34 



A1 2 3 c=102*8 . 0*1825=18*78 

 Alg c= 54*8 . 0*2143=11-74 



7*04=3. 2-35 



„ Sc 2 3 c=136*0 . 0*1530 = 20*81 

 Sc 2 c= 88*0 . 0*1454=12*80f 



8*01 = 3. 2-67 



* Our determinations refer to pure oxides obtained by chemical operations. 

 They are also strictly corresponding and comparable. Other determinations with 

 native alumina (sapphire), made by different methods (Kegnault, Neumann), gave a 

 higher number. Determinations by means of the ice-calorimeter always give smaller 

 results, because the standard measure for the heat developed is greater (1 calory = 

 mean of the specific heat of water between — 100° C.) . 



f The atomic heat of scandium is supposed to be =6 - 4, according to the law of 

 Dulong and Petit. 



