568 



SCIENCE 



[N. S. Vol. L. No. 1303 



DISCUSSION AND CORRESPONDENCE 



CHARCOAL ACTIVATION 



At tlie thirty-sixth general meeting of the 

 American Electro- Chemical Society held in 

 Chicago in September, K". K. Chaney pre- 

 sented a paper on charcoal activation in 

 which he states that the general theory in Us 

 complete form rests upon two postulates, one 

 of which is "that elementary carbon (other 

 than diamond and graphite) exists in two 

 modifications, ' active ' and ' inactive ' or 

 alpha and heta." 



It would seem from data obtained here that 

 the definitions of active and inactive would 

 need to be modified before this classification 

 can have any meaning, since charcoal can be 

 made which is the reverse of other charcoals 

 in that it is relatively more active for hydro- 

 gen than for nitrogen as shown by the follow- 

 ing data : 



Each of the volume measurements given 

 were calculated from pressure readings and 

 are reduced to normal pressure and tempera- 

 ture. The amount of charcoal used in each 

 case was 25. Y gms. and this was left at liquid 

 air temperature until saturated. The gases 

 were used separately and not as mixtures. 



The difference in treatment of the last 

 three samples was slight yet Sample 1 shows 

 figures lying on the outside of those for 

 Sample 2, i. e., the figures of Sample 1 have 

 approached each other for Sample 2. Much 

 more striking samples can no doubt be pre- 

 pared. 



A report of this work will be published when 

 completed but this will serve to point out an 

 apparent incompleteness in the theory set 

 forth by A. B. Lamb^ and by IST. K. Chaney. 



1 Not saturated in this particular case. 



2 J. Ind. and Eng. Chem., 1919, 11, 420-467. 



The author is indebted to Dr. H. B. Lemon 

 for valuable advice and assistance in this 

 work. 



H. H. Sheldon 



The University of Chicago 



AGED BEAN SEED, A CONTROL FOR 

 BACTERIAL BLIGHT OF BEANS 



During the progress of the investigational 

 work on bacterial blight of beans {Bacterium 

 phaseoli E. F. Sin.) at the Oklahoma Agricul- 

 tural Experiment Station many measures for 

 control were attempted. The most successful 

 method so far evolved is that of eliminating 

 the disease by the use of aged seed. It was 

 known that the causal bacteria could be cul- 

 tivated from infected seed for only a limited 

 time. 



With this fact in mind the infected seed 

 raised in our experimental plots each year 

 was saved and stored. Seed four and five 

 years old has never produced blighted plants 

 but the percentage of germination has been 

 so low as to prohibit its use under actual 

 farming conditions. Two- and three-year-old 

 seed has with one exception given blight-free 

 plants. This one exception occurred early in 

 the work and in view of later results must be 

 ascribed to accidental infection. 



Results secured indicate that the use of 

 two- and three-year-old bean seed furnishes 

 blight-free plants when planted upon unin- 

 fected land and at a siifficient distance from 

 other bean patches to insure no accidental in- 

 fection. Such seed moreover has a sufficiently 

 high percentage of germination to make its 

 use practical under actual farming conditions. 

 The results of the investigational work 

 which have been completed will be published 

 in the near future. 



C. W. Eapp 



Department op Hoeticdltuee, 

 A. & M. College, 

 Stillwater, Oklahoma 



note on the flagellation of the 

 nodule organisms of the 



LEGUMINOS^ffi 



In again taking up the question of flagella- 

 tion of the nodule bacteria, the findings re- 



