An Attempt to Estimate the Vitality of Seeds. 



70 



IV. " The Mineral Constituents of Dust and Soot from various Sources." 

 By Professor W. N. Hartley, F.R.S., and Hugh Eamage. 



V. " Notes on the Spark Spectra of Silicon as rendered by Silicates." 

 By Professor W. N. Hartley, F.E.S. 



VI. " On the Conductivity of Gases under the Becquerel Rays." By 

 the Hon. R. J. Strutt, M.A., Fellow of Trinity College, Cam- 

 bridge. Communicated by Lord Rayleigh, F.R.S. 



" An Attempt to Estimate the Vitality of Seeds by an Electrical 

 Method." By Augustus D. Waller, M.D., F.R.S. Received 

 January 28 —Read February 21, 1901. 



The present observations form part of an extensive series of experi- 

 ments by which I am engaged in verifying whether or no " blaze 

 currents "* may be utilised as a sign and measure of vitality. 



An inquiry of this scope necessitates superficial examination of 

 many varieties of animal and vegetable matter, and the closer study 

 of certain favourable test-cases. 



I have selected as such a test-case, the "vitality " of seeds, and have 

 chosen for my purpose beans (Phaseolus) which are anatomically con- 

 venient and practically easy to obtain of known age. 



But before entering upon the results in this particular test-case, I 

 think it advisable to preface those results by a brief indication of the 

 principle involved in all such experiments. 



The method of investigation is similar to that adopted in the case of 

 the frog's eyeball,* the complications of the principle and a tentative 

 explanation of such complications is reserved for future discussion in 

 a more comprehensive memoir. 



By " blaze current " (the term which I was led to adopt by the study 

 of retinal effects) I mean to denote the galvanometrical token of an 

 explosive change locally excited in living matter. An unequivocal blaze 

 current electrically excited is in the same direction as the exciting 

 eurrent, i.e., it cannot be a polarisation counter-current. (An equivocal 

 blaze current, in the contrary direction to the exciting current, i.e., not 

 at first sight distinguishable from a polarisation counter-effect, also 

 exists, but is not taken into consideration in this communication.) 



* A. D. W. — " On the 'Blaze Currents' of the Frog's Eyeball," 1 Koy. Soc 

 Proc.,' vol. 67, p. 439, and ' Phil. Trans.,' 1901. 



Although the theoretical explanation of these currents is not now in question, 

 it may here be remarked that the unequivocal or homodrome blaze current is 

 probably of local post-anodic origin (the previously anodic spot being now strongly 

 electro-positive to the previously kathodic spot), while the equivocal or hetero- 

 drome blaze current is probably of local post-kathodic origin (the previously 

 ikathodic spot being now strongly electro-positive to the previously anodic spot). 



