50 



On the Rare Earths and their Sulphates. [Nov. 18, 



Elements. 



Atomic 

 weight. 



Oxides. 



Anhydrous 

 sulphates. 



Hydrated 

 sulphates. 



Mole- 

 cular 

 heat. 



Mole- 

 cular 

 volume. 



Mole- 

 cular 

 heat. 



Mole- 

 cular 

 volume. 



Mole- 

 cular 

 heat. 



Mole- 

 cular 

 volume. 





89-5 



23-29 



44-99 



61-60 



178-80 



137-91 



240-55 





166-0 



24-70 



43-98 



64-48 



168-57 



13813 



240-25 





173-0 



25-45 



42-94 



65-87 



167-15 



13911 



236-79 





139-0 



24-42 



50-31 



66-90 



157-22 









146*5 



27-62 



49-07 



6896 



155-55 







Especially with regard to beryllia, and the question of its real 

 composition, the values given above are of the greatest importance. 

 In respect of this we observe that : 1st, the atomic heat of oxygen in 

 beryllia is identical with that in alumina and nearly identical with the 

 same value in other closely related oxides, if beryllia = Be 2 3 (see our 

 preceding paper, p. 42) ; 2nd, under the same supposition the 

 molecular heat and volume of beryllia and alumina are nearly identical, 

 whether the latter earth be examined in the state of crystallised 

 sapphire or of an amorphous powder, and, further, if we consider 



Ah 1 



chrysoberyl not as an aluminate, but as ^ 2 j> 3 , this mineral has 



yielded identical values ; 3rd, the molecular heat and value of beryl- 

 lium sulphate, compared with the same values for the other nearly 

 allied sulphates of aluminium, scandium, gallium, and yttrium, support 

 the formula Be 3 3 which we have given. 



Taking into consideration the above-mentioned circumstances, and 

 those related in our former papers, with the fact that the atomic heat 

 and volume of metallic beryllium, as well as the molecular heat and 

 volume of beryllia and its sulphate, would assume values quite ex- 

 ceptional, if the formula for the oxide were BeO, we think, there- 

 fore, the question of the valence of beryllium may be considered 

 as finally decided. In fact, there is no physical property of beryllium, 

 beryllia, or its sulphates, which does not testify to our view 

 being the correct one, and from a chemical point of view the same 

 holds good. It is, we think, unnecessary to take up space here with 

 a repetition of the various reasons which support this conclusion. 

 We refer, therefore, to our detailed paper on beryllium, above quoted, 

 and only mention here that this metal belongs on account of its 

 sulphate, 



3K 2 S0 4 +Be 3 3S0 4 , 



to the series of the gadolinite and cerite metals, this salt having a 

 composition, typical for all the members of this series (Be, Sc, Y, La, 

 Oe, Di, Tr, Y a , Y^, x, Er, Tm, Yb). • The series of these elements, the 



