CHEMISTRY. 



245 



On the whole it seems safest to choose the rounded-off value 31.02 for 

 the atomic weight of phosphorus. 



This investigation has been described in the Communications of the Eighth 

 International Congress of Applied Chemistry, vol. 11, pp. 21-36. 



The analysis of ferric oxide by reduction in hydrogen, begun last year by 

 Mr. C. R. Hoover (see Year Book No. 10) with terrestrial material, has 

 been completed by the investigation of meteoric material. The following 

 table gives the results of all the experiments : 



It can be seen in the first place that terrestrial and meteoric material seem 

 to be identical. In the second place, the final result is very slightly higher 

 than that found by Baxter, Thorwaldson, and Cobb by the analysis of fer- 

 rous bromide (see Year Book No. 9). The results of the two investigations 

 are compared below. 



The rounded-oft' value 55.84 seems to represent the real atomic weight 

 of iron. 



This investigation has been described in the Communications of the Eighth 

 International Congress of Applied Chemistry (vol. 11, pp. 37-52). 



The investigation upon the atomic weight of arsenic by the titration of 

 arsenic trioxide against iodine, begun some time ago by Mr. G. W. Harris 

 (see Year Book No. 9), has been extended by him to include the use of tri- 

 oxide which has been sublimed in a vacuum. Contrary to expectation, this 

 material yields, for the atomic weight of arsenic, a slightly higher value than 

 trioxide which has been sublimed in nitrogen. Aside from this lesser reduc- 

 ing power, no diflrerence could be observed between the two sorts of material. 

 At the same time Mr. P. C. Voter, by a very similar method, has compared 

 arsenic trioxide with iodine pentoxide, and has found similar differences in 

 the reducing power of arsenic trioxide sublimed in different ways. 



