September 25, 1908] 



SCIENCE 



413 



It has been stated by Sir William Eamsay :' 



" As sodium and potassium are much, more 

 widely distributed than lithium, it is more 

 likely that they are the chief products from 

 copper, and that some modifying circumstance 

 has determined the formation of a trace of 

 lithium. . . . Lithium was mentioned be- 

 cause it is an unlikely constituent of dust, 

 glass, copper, etc., which were tested specially 

 to prove its absence." 



There are two statements here which, ac- 

 cording to my experience, appear to require 

 ■modification. That potassium and sodium are 

 more abundantly distributed than lithium is 

 true, but that these are more widely dis- 

 tributed is not strictly correct; nor can it be 

 accepted as unquestionable that lithium is an 

 unlikely constituent of dust, glass, copper, etc. 

 Evidence to the contrary is based upon facts 

 divided into three categories — firstly, those de- 

 rived from the qualitative spectroscopic an- 

 alysis of common ores and minerals usually 

 associated with the alkali metals; secondly, 

 analysis of the crude salts of the alkalies, 

 such as the Stassfurth minerals and nitrates 

 from Chili and Bengal, show that they con- 

 tain lithium and rubidium, with not unfre- 

 quently csesium. Facts belonging to the third 

 category are derived from experimental evi- 

 dence, which is both quantitative and spectro- 

 graphic, the source of the spectra being the 

 oxyhydrogen flame. When half a gram of 

 material yields a photograph of the spectrum 

 of lithium on which the four chief lines are 

 visible— namely, A A. 6708, 4603.07, 4132.93 and 

 3232.82— there cannot be less than 0.0089 

 gram of lithium present. When only the 

 lines 6708.0 and 4603.07 are visible, the quan- 

 tity is not less or more than 0.0041 gram. 



When only the red line is photographed the 

 quantity is not more than 0.002 gram, and 

 with half this quantity the line ceases to be 

 photographed. It follows, therefore, that from 

 the evidence afforded by the number of plates 

 on which this line appears there could scarcely 

 be less lithium in the 0.5 gram of material 

 analyzed than 0.2 per cent. 



Further results have been obtained with 



'Nature, March 5, 1908, p. 412. 



several other metallic compounds, but the 

 sensitiveness of the flame reaction varies ex- 

 traordinarily with the spectra of different ele- 

 ments. 



Mr. Ramage and I found in 170 common 

 ores and minerals potassium and sodium, 

 and with these common elements rubidium 

 and lithium were very generally associated. 

 Thus, of sixty-two iron ores, rubidium was 

 found in sixty-one. In sixteen re I hfematites, 

 massive minerals of the purest type, rubidium 

 was contained in four. Where potassium and 

 rubidium occurred lithium was invariably 

 found. It was found in limestones, in dust, 

 in the Bessemer flame, in ordinary pipeclay, 

 tobacco pipes, and a great variety of siliceous 

 minerals, such as the Dublin granites; in 

 Donegal kyanite, which contains 98 per cent, 

 of aluminium silicate; and in asbestos. It 

 was found in dust which fell from the clouds, 

 in volcanic dust, in soot, in flue-dust from 

 chemical works, and in that from copper 

 smelting and refining works. This last ma- 

 terial contained lithium, sodium, potassium, 

 rubidium and coesium, copper, silver, calcium, 

 strontium, aluminium, gallium, indium, thal- 

 lium, iron, nickel, cobalt, manganese, chrom- 

 ium, lead, zinc, cadmium and tin. Upon 

 such evidence as this it is impossible to cor- 

 roborate the statement that potassium is a 

 more widely distributed element than lithium, 

 or that lithium is an unlikely constituent of 

 dust, glass, copper, etc. 



SPECIAL ARTICLES 



ON THE OEBITOSPHENOID IN SOME FISHES 



I WISH to call attention to the following 

 paragraph recently published by Dr. L. S. 

 Berg^ in reference to an orbitosphenoid al- 

 leged by different authors from time to time 

 to exist in various fishes. 



Das Orbitosphenoid fehlt bei alien untersuchten 

 Formen. Prof. Starks, der diesen Knochen bei 

 den Fam. Beryeidae imd Monooentridae fand, sagt 

 in seiner interessanten Abhandlung folgendes:^ 



' " Die Cataphracti des Baikal-See," p. 26. 

 Wissenseh. Baikal-See Exped., Lief III., 1907. 



'Proo. V. 8. Nat. Mus., XXVII., 1904, p. 601. 

 " It is remarkable to find this archaie character 



