OCTOBEK 8, iy<^8J 



NA TURE 



:93 



potassium salts in the cell, and he ascribed their localised 

 situation to surface-tension effects. Prof. MacDonald con- 

 sidered that these local appearances were explained by 

 these points being stimulated portions of the protoplasm. 

 Dr. Hewitt read a paper advocating improvement in the 

 training of ana;sthesists. He pointed out that the number 

 of deaths from anaesthesia is increasing, and recommended 

 that all medical students should be taught, by a qualified 

 instructor, the best method of administering anaesthetics. 

 Prof. Waller, F.R.S., demonstrated tracings obtained from 

 muscles immersed in saline containing varying percentages 

 of chloroform, ether, or alcohol. The relative toxicity of 

 these drugs is that i molecule of chloroform= 12 molecules 

 of ether=ioo molecules of alcohol. 



On the Friday morning the first item was a discussion 

 on mental and muscular fatigue, introduced by Dr. W. 

 McDougall. He stated that fatigue is the change in 

 ratio of two variable factors, one of which is the amount 

 of available energy and the other the resistance which has 

 to be overcome. .\s the resistance rises it is more difficult 

 to do work until a point is reached where fatigue is 

 manifested. This fatigue can be overcome by some more 

 stimulating occupation, but in the end the subject is left 

 more fatiguW. He also discussed the effect of waste pro- 

 ducts and the removal of reserve food material on the 

 activity of the cells. The resistance, which he supposed 

 to take place at the synapse, is protective, as it prevents 

 too great a drain of energy by continued action. Rise of 

 resistance in one path diverts the impulse into another 

 path, and this is exemplified by the difficulty of maintain- 

 ing the attention on any one detail, as fatigue is delayed 

 by minute variations in the object of attention. He then 

 illustrated various nervous disorders as depending on the 

 ratio of resistance to energy. Prof. MacDonald treated 

 the subject of muscular fatigue, pointing out the change 

 in distribution of salts and water during muscular con- 

 traction. Potassium salts are liberated in the central 

 portion of the sarcomeres, thus causing a rise in osmotic 

 pressure, and this attracts water from the neighbouring 

 portions of the muscle fibre, causing this portion of the 

 sarcomere to swell laterally. The contraction is the result 

 of the shortening due to transference of water fro]n the 

 longitudinal to the transverse axis of the muscle. Prof. 

 Milroy spoke about fatigue of colour sensations in simul- 

 taneous contrast. Mr. Sackville Lawson gave some 

 measurements of skin sensation by the pesthesiometer, 

 showing that mental fatigue diminishes the acuity of 

 touch sensations. .Several others took part in the dis- 

 cussion. Prof. Elliot Smith, F.R.S., then gave two com- 

 munications. The first, in conjunction with Prof. Wilson, 

 described the results of electrical stimulation of the cerebral 

 cortex of certain lemurs. The second presented a map of 

 the brain showing different areas which correspond to 

 different naked-eye appearances of sections made trans- 

 versely to the cortex. 



During the afternoon session the following papers were 

 read : — Prof. Ootch, F.R.S., showed tracings of photo- 

 electric changes in the eye on exposure to light. The 

 fundamental change is a prolonged electric current due to 

 changes in the visual purple, because this current does not 

 appear after the visual purple has been bleached. .'\t the 

 moments of exposure and cutting off of light there are 

 more intense currents which are only of short duration, 

 but they occur even after bleaching of the visual purple. 

 These two rises are mounted on tlie more prolonged rise 

 due to the visual purple. Repeated illumination causes 

 the appearance of a precursor to the sudden rise due to 

 illumination, and this precursor is a current in the reverse 

 direction to the other currents. All colours of light can 

 bleach the visual purple. Dr. Edridge-Green described 

 methods for testing colour-blindness, and demonstrated 

 annaratus for performing the various tests. Prof. Waller, 

 F.R.S., presented the report of the committee on the 

 electrical phenomena and metabolism of arum spadices. 

 Dr. >racLean described experiments showing that all the 

 nitrogen in lecithin is not present as choline, and Sir 

 James Grant read a paper on the gastro-intestinal 

 ganftlionic nervous system. 



Monday morning was commenced by a discussion on 

 instruction of school teachers in physiology and hygiene, 

 introduced by Prof. Sherrington, F.R.S. He pointed out 



KO. 2032, VOL. 78] 



that school teachers, having the charge of so many 

 children, should know how to take care of their health 

 and be able to detect certain departures from the normal. 

 Phvsiology is the basis of hygiene, and if physiology is 

 known hygiene follows as a practical and common-sense 

 application of its laws. Psychology is also important, as 

 it gives the teacher an insight into the minds of his 

 pupils ; but here again physiology should be known first. 

 The subject should not be'taught by books alone, but by 

 demonstrations and practical work, as that is the only 

 way really to appreciate any science. Prof. Thompson 

 detailed tlie steps that had been taken to teach physiology 

 to school teachers in Ireland. Prof. Gotch, F.R.S., said 

 that the teacher should learn physiology to apply it, but 

 not to teach it. .Any instruction to the children should 

 be by example and not by precept. Dr. McVittie gave 

 instances of the effect of neglect of hygiene in schools. 

 Other speakers emphasised the importance of teachmg 

 physiology to school teachers in order that the general 

 public mi'ght have a more enlightened view of hygiene, 

 especially 'personal hvgiene. Prof. Sherrington then pre- 

 sented the report on 'the conditions of health essential to 

 the carrying on of the work of instruction in schools (pre- 

 pared for Section L). After the closing of the discussion 

 Prof. A. Kossel (Heidelberg) read a paper on amyloid, 

 identifying the various radicals which enter into its con- 

 stitution. Dr. Cathcart described experiments showing 

 that various substances introduced into the pyloric portion 

 of the stomach cause secretion in the fundus. Tap-water, 

 although causing energetic movements of the pyloric 

 segment, was about the only substance which did not 

 cause secretion. It was not definitely determined whether 

 the secretion is due to chemical or nervous stimulation. 

 Dr Ellison showed records illustrating the effect of intra- 

 venous injection of a substance isolated from commercial 

 peptone. Dr. Dawson Turner read a paper on the ha;mo- 

 renal index, and demonstrated growth by osmosis after 

 the method of Prof. Leduc. 



At the afternoon meeting Dr. Copemnn, h.K.^., pre- 

 sented the report of the committee on body metabolism in 

 cancer Dr Page Mav gave lantern demonstrations show- 

 ing (a) a hitherto undescribed (postero-septal) tract in the 

 spinal cord, and (b) cells and tracts concerned in paralysis 

 and recoverv from paralysis. Mr. Walker read a paper 

 describing the effect of two antisera prepared in rats by 

 injecting in one case extract of testes and in the other 

 carcinoma cells from an experimental tumour. These anti- 

 sera, injected into mice infected with the same strain of 

 ;xperimental tumour used in preparing the second anti- 

 serum, api>eared to interfere with the development of the 

 n-rowth. Prof. McWeenev described the technique used 

 bv him in carrying out the biological method of identify- 

 in« blood stains, and he also testified to its v.ilue from a 

 m?dico-legal standpoint. Prof. B. Moore read a paper 

 for himself and Dr. Roaf, on the action of acid and alkali 

 on the .rrowth and division of animal and vegetable cells. 

 The sitttng was terminated bv a lantern demonstration, by 

 Dr Herring, of the changes in the pituitary after 

 rlivroidectomV. Removal of the thyroid causes a coUo.d- 

 like substance to be formed in the pituitary, and this sub- 

 stance passes through into the third ventrice, thus reach- 

 ing the cerebro-spinal fluid. . , c .• , r> 

 On Tuesdav morning a joint meeting with Section D 

 was held. Most of the papers are noted under the pro- 

 ceedings of that section, but the two following papers are 

 of phvsiological interest. Dr. Nierenstein described experi- 

 ments showing that atoxyl combines with proteins, but 

 the diacetvl compound does not. J.. v,vo *e acetyl com- 

 pound is hvdrolvsed, and acts like atoxyl He compared 

 the pharmacological action to the chemical process of dye- 

 hi« where the chromophore is represented by the arsenic 

 and the chromogen by the amido-group in atoxyl, and the 

 mordant is replaced bv protein. Prof. B. Moore described 

 the effect of manv substances upon experimenta t/™''no- 

 somiasis. The combined treatment, using atoxy followed 

 by mercury, is the best, and the only other metal tha." can 

 comoare in action with arsenic is antimony. 



The section closed bv a meeting on Tuesday afternoon, 

 with Lord Aberdeen in the chair. Sir Robert Matheson 

 read a paper on the anti-tuberculosis campaien in Irekand. 



