January 25, 1918] 



SCIENCE 



99 



and 1/A = 2992 intervals of 90 units are pres- 

 ent, at 1/A = 3304 intervals of 106 units, and 

 at 1/X^3571 intervals of 77 units, but these 

 series of shorter intervals do not include as 

 large a total number of bands as the series of 

 longer intervals. 



There appears, however, to be an entirely 

 different scheme of classification, which is 

 offered the reader as an alternative plan. It is 

 found that several well-filled groups of bands 

 can be arranged in pairs about a few centers. 

 These centers take on more interest when it is 

 found that they coincide with lines of the 

 mercury spectrum. Occasional pairs from 

 the Geissler tube spectrum of iodine can be 

 arranged about the same centers, such lines 

 being connected by dotted arcs in Spectrum 

 No. 3. It is understood that Spectrum No. 3, 

 like Spectrum No. 2, is a replica of Spectrum 

 No. 1, which was plotted from the reciprocals 

 of McLennan's values. The arcs in Spectrum 

 No. 3 show how the bands can be grouped in 

 concentric pairs. 



In Table II. is given the frequency num- 

 bers of the mercury centers with the apper- 

 taining fluorescence bands, as well as the dif- 

 ferences in frequency between bands and mer- 

 cury center. Positive differences indicate that 

 the bands are of smaller frequency and nega- 

 tive differences that the bands are of larger 

 frequency than the frequency of the center. 

 Although it is evident that the pairs are not 

 always equally spaced about the centers the 

 errors are no greater than those observed in 

 the first method of classification. The mer- 

 cury line or pair of lines which serves as a 

 center is generally a fairly prominent line in a 

 group of mercury lines, an exception being the 

 first center, 1/A = 2287, or A = 4372, which is 

 a dim satellite of A ^4359. 



It is of interest to observe, in comparing the 

 two plans of classification, that the second is 

 not so universal in its application as the first, 

 while the use of mercury centers suggests 

 something akin to resonance, which is con- 

 trary to Professor McLennan's observations. 



H. L. Howes 

 Physical Laboratory op Cobnell Unitebsitt, 

 October 30, 1917 



THE AMERICAN ASSOCIATION FOR 



THE ADVANCEMENT OF 



SCIENCE 



SECTION G— BOTANY 



The only meeting of Section G for reading 

 of papers took place at 2 p.m., Saturday, De- 

 cember 29, 1917, at the school of applied sci- 

 ence, Carnegie Institute as a joint session 

 with the Botanical Society of America and the 

 American Phytopathological Society. The 

 program consisted of the Vice-Presidential ad- 

 dress followed by a Symposium on War Prob- 

 lems in Botany as outlined in the printed 

 program. Dr. Bailey was prevented by war 

 work from presenting his paper on the Na- 

 tional Research Council. Dr. Coulter was not 

 present, but his paper was read by Dr. H. C. 

 Cowles. Dr. Smith was not present and his 

 paper was not presented. 



At the business meeting following the read- 

 ing of papers, D. T. MacDougal was elected 

 member of coimcil, R. A. Harper member of 

 Sectional Committee for 5 years and A. B. 

 Stout member of general committee. 



It was moved and carried that a committee 

 be appointed by the chair to report to a later 

 business meeting of the section on two con- 

 siderations: (a) The organization of American 

 botanists to forward the project of a patho- 

 logical survey as suggested in the invitation 

 paper of Dr. G. R. Lyman; (b) the possibility 

 of assignment of drafted men of technical 

 training and ability to scientific work of 

 national importance and a recognition in some 

 way that they are engaged in war service. 

 The committee appointed by the chair con- 

 sisted of G. R. Lyman. L. H. MacDaniels and 

 C. L. Shear. 



It was moved and carried that the business 

 meeting adjourn till 9 a.m. Monday, Decem- 

 ber 31. 



At the meeting of the Sectional Committee, 

 December 29, the following members were 

 present: Gager, Livingston, Blakeslee, Selby, 

 MacDougal. Newcomb. Bartlett. Cook, Shear. 

 A. F. Blakeslee was nominated for vice-presi- 

 dent of the section for the ensuing year and 

 Mel T. Cook for secretary for five years. 



At the request of a group of botanical 



