Januaey 15, 1897.] 



SCIENCE. 



101 



tory character to the diagram, and was as 

 common in Central America, where it gave 

 rise to the sacred ' j^ear ' of 260 days, as in 

 many parts of the Old World. Such calen- 

 dars were not originally time-measurers, 

 but divining schemes, as Sahagun expressly 

 states. 



THE RACIAL GEOGKAPHY OF EUEOPE. 



The complex and historically important 

 subject of the geographical distribution of 

 racial types in Europe has been closely 

 studied by Prof. W. Z. Eipley, and will be 

 made the theme of a series of articles in 

 the Popular Science Monthly, beginning with 

 the February number. The articles will 

 be amply illustrated by maps, diagrams and 

 some fifty hitherto unpublished portraits of 

 race types reproduced from original pho- 

 tographs. Having had the advantage of 

 looking through Prof. Ripley's collections 

 upon this branch of anthropology, I feel 

 sure his articles will add much new material 

 and many valuable suggestions to a com- 

 prehension of the racial questions of modern 

 Europe. Such points as the cephalic in- 

 dices, the distribution of blonds and bru- 

 nettes, the comparison of stature and 

 weight, etc., when studied from hundreds 

 of thousands of individual measurements, 

 must lead to results more secure, and per- 

 haps quite differing from those hitherto 

 published. D. G. Beinton. 



University of Pennsylvania. 



NOTES ON INORGANIC CHEMISTRY. 

 In the last number of the Chemical News, 

 Prof. John Waddell, of the Canadian Royal 

 Military College, describes a large number 

 of experiments on the permeability of vari- 

 ous elements to the Rontgen rays. He 

 concludes "that the elements may be di- 

 vided into two classes, those of low atomic 

 weight and those of higher atomic weight, 

 the transition taking place between the 

 atomic weights of 30 and 40. Among the 



higher elements the opacity is probably not 

 far from being proportional to density, but 

 with elements of low atomic weight the 

 same law does not hold; sodium, for in- 

 stance, is decidedly more permeable than 

 aluminum; lithium and sodium are more 

 nearly alike. Metals and non-metals cannot 

 be differentiated from each other; boron 

 is less permeable than sodium, and sodium 

 is less permeable than oxygen." 



The cause of poisoning from wall papers 

 containing arsenic has often been ascribed 

 to the formation of arsin (arsenetted 

 hydrogen) by the action of mould on the 

 paper. An account is given in the last 

 Berichte of a number of experiments carried 

 out by O. Emmerling bearing on this sub- 

 ject. Several different kinds of bacteria 

 were grown in cultures containing arsenic, 

 and in no case was arsin present in the 

 gases evolved. The same was true when 

 several different species of moulds were 

 used. A moist arsenical paper was exposed 

 in a tube in a current of air till it had on it 

 numerous colonies of moulds, yeasts and 

 bacteria. The air was drawn through a 

 silver nitrate solution and no trace of arsin 

 was present. Hence it would seem that 

 danger from arsenical wall papers is not 

 from the formation of arsin, but from parti- 

 cles of dust given oflf from the paper. Hap- 

 pily, few wall papers are at present manu- 

 factured containing arsenic. 



In a letter to Nature (Nov. 26), on the 

 subject of osmotic pressure and ionic disso- 

 ciation. Prof. Henry E. Armstrong uses 

 these words : " There can be no doubt that 

 in so far as tueak solutions are concerned, a 

 law has been discovered which is broadly 

 true in mathematical form; yet I have no 

 hesitation in asserting that the fundamen- 

 tal premises on which it is based are desti- 

 tute of common sense, in the opinion of 

 those who look at these matters without 

 leaving chemical experience out of ac- 



