348 



NATURE 



[July 3, 1919 



anhydride may combine with this water and so 

 retard the final dehydration. 



But, whatever may be the true explanation, it 

 cannot be doubted that this obstinate retention 

 by heated, and even fused, borax of about 02 per 

 cent, of water is the main cause of error in all 

 previous attempts to determine the atomic weight 

 of boron by means of this salt. That the com- 

 plete dehydration of borax is difficult was recog- 

 nised by Dobrovolsky so far back as 1869, and 

 was known to Hoskyns Abrahall, who concluded 

 that the dehydration of borax was untrustworthy 

 for ascertaining- an atomic weight ratio. 



In 1893 the late Sir William Ramsay and Miss 

 Emily Aston published the results of a redeter- 

 mination of the atomic weight of boron which 

 appeared to them to confirm the commonly 

 accepted value of ii'o. Their methods consisted 

 (i) in ascertaining the water of crystallisation in 

 borax, and (2) in converting dehydrated borax 

 into sodium chloride by repeated distillation with 

 hydrochloric acid and methyl alcohol, according to 

 the process of Gooch and Rosenbladt. All the 

 weighings are given in their paper to seven places 

 of decimals — an assumption of precision scarcely 

 warranted by the circumstances, and an instance 

 of what Kopp was wont to call Decimahpielerei. 

 The results of the first method varied from 11 '04 

 to io'85; the mean value adopted was io*92i. 

 Two series were made by the distillation method ; 

 the first gave values varying between 11 '015 and 

 10*879: adopted mean = io"952 ; in the second 

 the extreme values were 1 0*992 and io'936 : 

 adopted mean io'966. In the last series the 

 amount of chlorine in the common salt was deter- 

 mined by gravimetric analysis in the usual way, 

 which afforded a new ratio. The numbers thus 

 obtained were uniformly above 11 (11 '003-1 1*091 : 

 adopted mean ii'o52). 



The details given by Ramsay and Aston permit 

 of a discussion of their observations in the light 

 of the facts obtained by Messrs. Smith and van 

 Haagen, and it is satisfactory to find that the 

 two sets of observations can be brought into com- 

 plete harmony. Indeed, certain inconsistencies 

 among the results of the English observers, on 

 which they themselves commented, but were un- 

 able to explain, are now cleared up, and serve to 

 corroborate the results of the American chemists. 



The recalculation of Ramsay and Aston's ex- 

 perimental numbers by means of the best-deter- 

 mined ratio of AgCl : NaCl shows that the incon- 

 sistency referred to becomes slightly greater. 

 From the weight of NaCl, B = 10*951 ; from that 

 of AgCl, B = ii"o6i, or a difference of fully i 

 per cent. Now the method which they adopted 

 to dehydrate borax combined with their low value 

 for the density of vitreous borax — 2*29, as against 

 the proper value, 2*357 — makes it practically 

 certain that the fused borax still contained ap- 

 proximately 0*3 per cent, of water, and that the 

 sodium chloride, although heated to 350°, still 

 retained water the amount of which may be com- 

 puted from the ratios. It was 0*214 P^'* cent. 

 By introducing these corrections, which are not 

 NO. 2592, VOL. 103] 



arbitrary, but fully warranted by the facts, 

 Ramsay and Aston's first series leads to the value 

 B = 10*901, and their second series to B = 10*909. 

 They agree, therefore, among themselves, and are 

 in conformity with the result of 10*900 obtained 

 by Messrs. Smith and van Haagen. 



As regards the new determination of the atomic 

 weight of fluorine, it must suffice to say that it 

 depends on the ratios of sodium fluoride to sodium 

 borate and sulphate, and on a cross-ratio between 

 sodium chloride and sodium fluoride. Eight deter- 

 minations varying between 19*002 and 19*008 gave 

 F = 19*005, which completely confirms the present 

 international value. T. E. Thorpe. 



THE PEACE TREATY AND MINERAL 

 FIELDS. 



THE Treaty of Peace has taken into account 

 the economic relations of the contracting 

 parties and the effect upon these of the peace 

 conditions to a degree that has never been 

 approached in any previous document of the kind. 

 It is not too much to say that, whereas all 

 previous peace treaties have been essentially 

 diplomatic, the present one is essentially indus- 

 trial in its outlook. The only mineral rights speci- 

 fically referred to are those involved in the cession 

 of the coal basin of the Sarre to France ; it is 

 difficult to understand, by the way, why, in the 

 published English version of the treaty, the 

 German spelUng of the name has been used 

 instead of the French. This cession bulks very 

 large in the Treaty, but is of far less importance 

 than would appear at first sight. It is estimated 

 that the total quantity of coal contained in the 

 Sarre basin is only 5*7 per cent, of the total 

 quantity owned by Germany, so that the loss to 

 Germany in respect of coal reserves is insignifi- 

 cant. From the point of view of annual output, it 

 is somewhat more important; Germany produced 

 in 191 3 about 191^ million tons of bituminous 

 coal, out of which the Sarre district produced 

 about 14 millions, or rather more than 7 per 

 cent. On the other hand, the possession of this 

 coal-field means a great deal to France. 



Before the war the total coal output of France 

 was about 42^^ million tons, so that the Sarre 

 coal-field will increase the ultimate producing 

 capacity by about 33 per cent. Of the total pro- 

 duction nearly 22 million tons came from the 

 Pas-de-Calais district, whilst the Nord district 

 produced nearly 8 millions — about 70 per cent, 

 of the entire production. These two districts 

 have been almost wholly wrecked by the 

 Germans ; owing to the configuration of this coal- 

 field, in which the coal-measures are overlain by 

 Secondary, highly water-bearing strata, it was 

 easy to do very serious damage by merely blow- 

 ing in the watertight shaft linings and thus 

 drowning out the pits ; owing, further, to the fact 

 that many of the more important collieries are 

 connected by drifts with each other, recovering 

 merely a few of the shafts or even sinking new 

 ones will not suffice, and practically all the old 



