Supplement to "Nature." March 5, 1908 



SUPPLEMENT TO '^NATURE." 



PHYSIOLOGICAL STIMULUS AND RESPONSE. 

 Comparative Electro-physiology. A Physico-physio- 



logical Study. By Prof. J. C. Bose. Pp. xliii + 760. 



(London : Lontjmans, Green and Co., 1907.) Price 



15s. net. 



IN sequence to his books on response in the living 

 and non-living (1902) and plant response 

 (1906), Prof. Chunder Bose has pubhshed a third 

 volume on comparative electro-physiology. Prof. 

 Bose has great ingenuity in device of experimental 

 .-ipparatus, fertility in initiating new lines of observa- 

 tion, and a clear style of setting forth his experi- 

 mental results and theoretical deductions ; neverthe- 

 less, we feel far from satisfied with his performance. 

 He strives constantly to group every result he obtains 

 under " some property of matter common and per- 

 sistent in the living and non-living substance," and 

 to explain by this assumed common underlying pro- 

 perty the diverse phenomena of response which occur 

 in metal wires, plant and animal tissues, on mechan- 

 ical, thermal, or electrical excitation. 



Prof. Bose says he started his investigations seven 

 years ago in order to demonstrate this underlying 

 unity, and we cannot help feeling that he has pre- 

 judged his phenomena, and, biassed by his philo- 

 sophical conceptions, may select his experimental 

 results and set before his reader those which confirm 

 the main line of his argument. Using the photo- 

 graphic method of recording, and the galvanometer 

 as the indicator of electrical response, he has pub- 

 lished a series of figures, each one of which illustrates 

 some argument in the text. No tables are given 

 showing the number of experiments done or the 

 failures and contrary results which occur in all lines 

 of fresh investigation, and thus, while we feel grate- 

 ful to Prof. Bose for suggesting fresh and fruitful 

 lines of research, we must wait for confirmation by 

 others of his many new and somewhat startling con- 

 clusions. 



To instance some of these. Prof. Bose maintains 

 that nerve, which is universally regarded as non- 

 contractile, " is not only indisputably motile, but also 

 that the investigation of its response by the mechan- 

 ical method is capable of greater delicacy, and freedom 

 from error, than that by the electrical." He 

 demonstrates the contractility of nerve by means of 

 the deflection of a spot of light reflected from a 

 mirror attached to a light lever, thus obtaining mag- 

 nification up to 100,000 times, but at the same time 

 states that it can be demonstrated even by a light 

 aluminium lever magnifying 50 times. This is 

 contrary to the result of an English physiologist, who 

 has, to our knowledge, tried a similar experiment. 

 Here we have a definite assertion supported by many 

 photographic curves and details of experiment, and 

 one which, when tested by others, can enable us to 

 arrive at a definite valuation of Prof. Bose's work. 

 Such an independent valuation is required, as Prof. 

 Bose and the English authorities on electrical 

 physiology have been greatly at variance. 

 NO. 2001, VOL. 77] 



Prof. Bose claims that the fibro-vascular bundles of 

 plants, which can be isolated in long lengths from 

 the frond of a fern or petiole of cauliflower, act as 

 vegetable nerves, the response being in every 

 respect similar to animal nerve, and being affected 

 similarly by ether, alcohol, ammonia, carbon dioxide,. 

 tetanus, &c. He regards the fibro-vascular system 

 which forms the venation of leaves as a " vast catch- 

 ment basin " for the reception of light stimuli and 

 their transmission to the parts of the plant which 

 are in the dark. By this nervous system, he says, 

 the tone of the whole plant is maintained. In regard 

 to Pflijger's law of the polar effects of currents, Prof. 

 Bose demonstrates photographs showing the like 

 effects on plant and animal structures, but finds that 

 " above and below a certain range of electromotive 

 intensity ihe polar effects of currents are precisely 

 opposite to those enunciated by Pfliiger." He 

 endeavours to prove that the response of nerve to 

 excitation consists of a positive and a negative vari- 

 ation, and that the tones of sensation, pleasure and 

 pain depend on the ascendancy of one or other vari- 

 ation. He seems to recognise no deficiencies in the 

 galvanometric method, and is unaware or neglectful 

 of the work done with the capillary electrometer and of 

 the diphasic variations obtained with this instrument 

 by Prof. Gotch. The galvanometer is far too inert 

 an instrument to demonstrate the true electrical 

 response of nerve. Prof. Bose says that 



" all the diverse phenomena of response may be sum- 

 marised in the two following formulae : — (i) Excitatory 

 response takes place by contraction and galvanometric 

 negativity. (2) Increase of internal energy induces 

 the opposite effect of expansion and galvanometric 

 positivity." 



" The first of these effects is simply demonstrated by 

 direct excitation of an excitable tissue. In order to 

 demonstrate the second, stimulus is applied at a dis- 

 tance from the responding point. In consequence of 

 sudden local contraction at the receptive area, a wave 

 of increased hydrostatic tension is transmitted with 

 great rapidity. Energy is thus conveyed hydraulically, 

 and at the distant point the transmitted effect induces 

 expansion and galvanometric positivity. This is 

 followed by the more slowly transmitted wave of true 

 excitation, which on its arrival gives rise to the 

 normal response of contraction and galvanometric 

 negativity." 



All we can say in criticism of this state- 

 ment is that while it may be true for plant tissue, 

 there is not a shadow of fact in favour of it holding 

 good for muscle, and we must remain unconvinced 

 by the evidence adduced by the author in favour of its 

 holding good for nerve, until his experiments on 

 the expansion and contraction of nerve have obtained 

 confirmation. 



Prof. Bose finds that a metallic wire, the stem 

 of a plant, and a nerve when suddenly submitted 

 to torsion j^ive the -same electrical response, and in 

 consequence is led to make the following statement : — 



" Bv the conception of matter itself, on the other 

 hand, as possessed of sensibility — that is to say of 

 molecular responsiveness, we attain an immediate 

 accession of insight into those physical interactions 



T 2 



