January 13, 1905.] 



SCIENCE. 



59 



cident, that there were a number of sub- 

 stances, notably quinoline, wliich convert 

 amorphous selenium into the more stable, 

 black, metallic modification. It is probable 

 that similar results could be obtained with 

 other elements. Kastle has shown that 

 the rate of change of yellow mercuric 

 iodide into the red form varies enormously 

 with the nature of the solvent. The first 

 thing that we need is a systematic study of 

 the allotropic forms of the elements, con- 

 sidering reaction velocity as well as equi- 

 librium. We next take up cases where the 

 change from one form to another can be 

 made increasingly difficult. The three 

 disubstituted benzene compounds, as I have 

 already said, are to be considered as dif- 

 ferent modifications, only one of which can 

 be stable as solid phase at any given tem- 

 perature and under atmospheric pressure. 

 According to the text-books o-phenol sul- 

 phonic acid changes readily into p-phenol 

 sulphonic acid on heating. When bromine 

 acts on phenol in the cold, p-bromphenol 

 is formed, while o-bromphenol is formed 

 when the reaction takes place at 180°. I 

 have not been able to find any record of 

 the p-brom compound changing into the 

 o-brom compound on heating; but the ex- 

 periment is worth trying. When we come 

 to the three dibrombenzenes, we have a 

 case where we know that the three forms 

 are identical in composition and where 

 there is certainly some sort of an equi- 

 librium at the time of formation because 

 the relative amounts of the modifications 

 can be changed by varying the conditions 

 of preparation. In spite of all this we 

 know no way of converting two of these 

 compounds directly into the third. We 

 could undoubtedly do it if we could raise 

 the temperature high enough, just as we 

 could also convert the elements. It is as 

 yet impossible to attain the temperature 

 at which the elements change rapidly, while 

 secondary reactions interfere in the case 



of the organic compounds. So long as we 

 can not change the two less stable forms of 

 any disubstituted benzene compound into 

 the most stable form, there is no reason 

 why we should expect to succeed in what 

 may, perhaps, be the impossible task of 

 simplifying the elements. 



Summing up, the future developments 

 in physical chemistry will comprise a 

 theory of concentrated solutions, further 

 applications of the phase rule and of the 

 theorem of Le Chatelier, a systematic study 

 of organic chemistry, and a theory of 

 catalysis. Wilder D. Bancroft. 



REPORTS OF COMMITTEES. 

 The following reports of committees 

 were presented to the council. They were 

 accepted and ordered printed : 



On the Intcrivational Congress of Americanists. 



The International Congress of Americanists 

 held its fourteenth biennial meeting in Stuttgart, 

 Germany, August 18-23, 1904. On June 1, 1904, 

 I received a communication from you announcing 

 my appointment as the representative of the 

 American Association for the Advancement of 

 Science at this meeting. The designation was 

 gladly accepted, as it had already been arranged 

 tliat I should attend the congress on behalf of the 

 Smithsonian Institution. 



I now have the honor to report that the meet- 

 ing was in every way a most gratifying success 

 and that the representation of the American As- 

 sociation was duly recognized and published in 

 the official bulletins of the congress. The attend- 

 ance was largely German, but representatives 

 from a dozen other countries were present and 

 took an active part in the proceedings. The 

 papers presented related almost exclusively to 

 American history and anthropology and especially 

 to South American subjects. The Germans as 

 well as the French have given very great atten- 

 tion to investigations on that continent. 



The next meeting of the congress is to be held 

 at Quebec in August, 1906. 



Very respectfully, 



W. H. Holmes. 



On Anthropometry. 

 The committee beg to report that individually 

 and as a committee they have been carrying on 



