I50 



REPORTS ON INVESTIGATIONS AND PROJECTS. 



Series H.-MnBRj : JAgBr. 



Number of 

 analysis. 



i6 



17- 

 i8 



19- 



20. 



21 

 22. 



23- 

 24 



25- 



26 

 27 

 28. 



29 



30. 

 31- 



Average . 



Sample 



of 

 MnBro. 



A 



A 

 A 

 A 

 C 

 C 



c 



A 

 A 

 B 

 B 

 B 

 C 

 D 

 D 

 D 



Weight of 



MnBro 

 in vacuum. 



Grams. 



5-58418 



5-63433 



653745 



4.81006 



4.88098 



5.63220 



6.52627 



5.79926 



3-59811 

 5-16335 

 3.92227 



449159 

 3-60073 



4-77393 

 3 57660 



5-69973 



Weight of 



AgBr 

 in vacuum. 



Giams. 



9.76578 



9-85362 



II. 43318 



8.41223 



8.53658 



9-85025 



II. 41309 



10.14223 



6.29286 



9.02975 



6.85984 



7-85587 

 6.29731 

 8.34919 

 6.25572 

 9.96845 



Atomic 



weierht of 



Mn. 



54-959 

 54-956 

 54-954 

 54-953 

 54-945 

 54-949 

 54-964 

 54-953 

 54-946 

 54-961 

 54-945 

 54-936 

 54-951 

 54-9+9 

 54930 

 54-947 



54-950 



Average, rejecting anal3'sis 30. 

 Average of Series I and II . . . . 



54951 

 54 953 



MnBro :2Ag. MnBr, ; -->AgBr. 



Average of analyses with — 



Sample A of MnBr,^ 54-957 54-954 



B MnBrj 54-957 54-947 



C MnBr^ 54-958 54-952 



D MnBrj 54 948 54-948 



A Ag 54-958 



B Ag 54-956 



C Ag 54-955 



The close agreement of the averages of Series I and II and of the 

 averages of analyses with different samples of material leaves no 

 doubt that the atomic weight of manganese lies ver)' near the average 

 of Series I and II, 54-953 (Ag = 107.930). 



Gombergf^ Moses, Universitj^ of Michigan, Ann Arbor, Michigan. 

 Grant No. 153. Study of triphenylmethyl and a7ialogoiis com- 

 pounds. (For first report see Year Book No. 3, page 106.) $500. 

 Abstract of Report. — Work under this grant was carried on with 

 the assistance of Dr. L. H. Cone. The influence of sunlight upon 

 solutions of triphenylmethyl was first investigated, as this influence 

 was found to be a disturbing factor in all our work. It was found 

 that in presence of certain solvents triphenylmethyl is reduced under 

 the influence of light to triphenylmethane. All our further work 

 was therefore carried on in absence of sunlight. A complete study 

 of the combinations of triphenylmethyl with the different classes of 



