ON THE DISSOCIATION OF OXY-H^MOGLOBIN. 281 



ascertained that Mr. Ff. Roberts is prepared to take part in the work, 

 should the funds necessary to meet his out-of-pocket expenses be forth- 

 coming. Mr. Roberts is acquainted with the technique required for the 

 research. 



The Committee therefore request that the grant of last year be held 

 at their disposal, and that in addition a like sum be added to it. 



Electromotive Phenomena in Plants. — Report of the Committee, consist- 

 ing of Dr. A. D. Waller (Chairman), Mrs. Waller (Secretary), 

 Professors F. Gotch, J. B. Farmer, and Veley, and Dr. F. O'B. 

 Ellison. (Drawn up byDv.A.D. Waller.) 



PAGE 



Appemdix. — On the Blaze Currents of LaurJ Leaves in relation to their Evolution 



of Prussic Acid. By Mrs. A. M. Waller 288 



I. Introduction. 



In last year's report of the Committee upon the Electrical Phenomena 

 and Metabolism of Arum Spadices principal stress was laid upon the 

 effects of heat upon the excitatory phenomena of animal and vegetable 

 tissues, gauged principally by their electromotive responses. 



We showed then (1) upon muscle, (2) upon nerve, (3) upon petioles 

 of plants that the brief application of an amount of heat insufficient to 

 effect injury elicits an electrical change that is the reverse of that 

 elicited by injury and by excitation; and as general conclusion of our 

 observation we found that the effect of ' thermic stimuli,' so called, is 

 anti-excitatory or inhibitory in character. 



Without having fully reconciled the apparent incongruity of this 

 result with the well-known fact that rise of temperature accelerates 

 chemical change and increases the excitability of living tissues in rela- 

 tion to brief stimuli, we have pursued our investigation of the general 

 relations between physiological phenomena and temperature in both 

 animal and vegetable tissues. 



• We have in particular investigated (1) the rate oE action of drugs 

 upon muscle and (2) the rate of change taking place in laurel leaves. 

 The study of laurel leaves has brought us back to the consideration of 

 the electrical phenomena associated with enzyme effects, and has led 

 us on to a special study of hydrocyanic acid. The elaboration of a 

 method for the quantitative estimation of hydrocyanic acid in laurel 

 leaves has placed in our hands a method for its quantitative estimation 

 in minute quantities in animal as well as in vegetable tissues. We have 

 further satisfied ourselves that the method is applicable (1) to medico- 

 legal cases of suspected poisoning by prussic acid or by cyanides, and 

 (2) for the purposes of agricultural chemistry.. 



Communications relating to the subject-matter dealt with by the 

 Committee have been made during the past year to the Physiological 

 Society and to the Royal Society. As regards the medico-legal applica- 

 tion of the method, we intend to submit it to criticism in the proper 

 quarter by a communication to the Royal Society of Medicine. 



