20 



NA TURE 



[November 4, 1897 



of those previously acting, namely simultaneous contrast, had 

 alone become valent. 



Prof. Halliburton and Dr. Mott made a communication on the 

 effects produced on the arterial blood-pressure by the intravenous 

 injection of choline, neurine, and allied substances. Normal 

 cerebro-spinal fluid produced no effect, while that obtained /(7j-/- 

 niortetji from cases of general paralysis of the insane produced a 

 fall of blood -pressure. This is not due to a proteid body present ; 

 for after coagulation by boiling, or precipitation by alcohol, a 

 similar effect is produced. Neurine hydrochloride in o'l per 

 cent, solution gave a similar fall, but in most cases this was 

 followed by a rise and then by a more persistent fall of blood 

 pressure. Choline hydrochloride in 0'2 per cent, solution gave 

 results identical with those obtained by the pathological cerebro- 

 spinal fluids. Blood taken from patients suffering from pseudo- 

 apopleciiform convulsions of general paralysis was precipitated 

 with alcohol, and the filtrate, after evaporation to dryness and 

 solution in saline, injected, and the effect produced corresponded 

 entirely with that obtained with pathological cerebro-spinal 

 fluids and with solution of choline. Normal blood gave a 

 negative result. The fall of blood -pressure produced by these 

 various reagents is cardiac in origin. This was established by 

 plethysmographic tracings and by experiments on the frog's and 

 mammal's heart. This agrees very well with what is found in 

 general paralysis, cardiac weakness, and enfeebled circulation. 

 Prof. Richet related experiments by which he had succeeded 

 in showing and measuring in the dog the refractory period of 

 the bulbar and cerebral nervous centres. The animal is cooled 

 down to 30° C. and anaesthetised. It will then react to electrical 

 stimulations of the cortex if the stimulations be not too 

 frequent. If the rhythm of these be i per second, the'responses 

 are equal in magnitude ; if 4 per second, there will be one large 

 and then one small response ; if 10 per second, there will be no 

 longer a response to each excitation but one to each alternate. 

 Half of the stimuli fall within a refractory period. The 

 duration of the refractory period is i/io". It is possible to show 

 that, as was originally indicated by the experiments of V. Kries, 

 volitional impulses have a frequency of repetition of about 10 or 

 II in a second. 



Dr. F. S. Lee brought forward the results of his continued re- 

 searches into the functions of the semicircular canals in fishes, 

 especially in regard to maintenance of equilibrium and to 

 locomotion. 



Prof. Anderson Stuart made an interesting communication on 

 the canal of Stilling. He also showed models illustrating the 

 horopter. 



Mr. O. Grunbaum contributed a communication upon the 

 effects of intermittent retinal stimulation. He exhibited the 

 results of several series of experiments stated in curves with 

 nieasure-s of speed of alternation as ordinate-heights and degrees 

 of illumination as abscissae. The curves so obtained possess 

 each an apex above, denoting that a sensation of continuous 

 stimulation results if the luminosity be below or beyond a 

 certain amount. The curve begins to descend some distance 

 prior to the use of a degree of luminosity such as to produce a 

 blinding after-image. 



Dr. A. Grunbaum gave a communication on muscle spindles 

 found in human muscles ; the communication was illustrated by 

 microphotograms. 



Profs. Boyce and Herdman contributed the results of their 

 investigations on "green oysters." They had demonstrated 

 copper in comparatively large quantity in the green leucocytes of 

 the American oyster. The green colour in these oysters is in 

 direct proportion to the copper present. The copper indicates 

 a pathological condition of these American oysters. They were 

 not prepared to state whether copper in the food of the oyster 

 can bring about the condition, but there is abundant evidence 

 to show that it can occur where no copper mines or other 

 evident sources of copper are present. The normal copper of 

 the haemocyanin of the blood, which is probably constantly 

 circulating through the body in minute quantity, may cease to 

 be removed, and so become stored in certain cells in the oyster. 

 The deposition of the copper in the large quantity found 

 appeared to them the result of a degenerative process. 



Prof. Boyce communicated a paper by Dr. Warrington 

 (Liverpool). The effects of ischoemia on the structural 

 features of nerve-cells were shown to be very marked. 

 Also the effect of cutting off from the anterior coronal 

 cells the afferent impulses usually impinging on them 

 was studied in cases where the posterior roots had been 



NO. 1462, VOL. 57] 



divided. Marked changes were found, which were minutely 

 described. On the other hand, attempts to discover changes in 

 the cells of the oculomitorius and facialis nuclei after section of 

 their nerve-trunks failed to detect any changes. 



In experiments of the kind mentioned above, in which changes 

 uniformly resulted, the typical picture of alteration is very charac- 

 teristic ; the cell becomes somewhat enlarged, is stained red, with 

 a small amount of blue chromophitic granules at its periphery, the 

 nucleus remaining well-marked. The changes go on to a further 

 swelling up of the cell, a disappearance of its nucleus, and 

 finally shrinkage and ultimate disappearance. The paper was 

 illustrated by microphotographs. The method of staining of 

 the preparations employed had been the methylene-blue and 

 erythrosin modification of Nissl's stain. 



Prof. Macallum made a long and important communication on 

 the structures of the nucleus and body of the cell, and described 

 the views at which he had arrived on this profound and difficult 

 subject. , • . 



Prof. Wesley Mills contributed interesting papers on the psychic 

 development of young animals, on the functional development 

 of the cerebral cortex, and on cortical cerebral localisation. 



Miss F. Welby contributed an interesting account of observ- 

 ations on the effect of curvesthetic vapours on,, the cardiac 

 muscle of the frog ; her remarks being illustrated by the 

 projection of the graphic records of the experiments. 



The morning of Tuesday, August 24, was devoted to a com- 

 bined meeting of the sections Physiology and Botany to discuss 

 the chemistry and structure of the cell. Several members of the 

 section of Chemistry also took part, the opening paper being 

 by Prof. Meldola. Profs. Marshall Ward, Armstrong, Green, 

 Macallum, Remsen, Farmer, and Halliburton, spoke in the 

 discussion. 



Prof. Meldola devoted his opening paper to a discussion of 

 the rationale of chemical synthesis of bodies formed by living 

 oiganisms. 



The presidential address by Prof. Foster was given in the large 

 Zoology Theatre of the University ; it was very numerously 

 attended. It was a retrospect of the history of physiology since the 

 previous meeting of the British Association at Montreal in 1884. 

 It was pointed out that the opportunities for studying physiology 

 had grown larger and more facile. " But there is still a larger 

 outcome from the professional chair and physiological laboratory 

 than the training of students. Each post for teaching is no less 

 a post for learning. Among academic duties the making of 

 knowledge is no less a duty than the distributing of it." 

 " Practical expression has been given to this feeling more vigor- 

 ously in Canada and the United States than in the old country." 

 " Physiology is destined, in consequence of its containing the 

 study of the actions of the brain, to modify the attitude of the 

 physiologist toward the world, and of the world toward the 

 physiologist. That physiology is, and must always be the basis 

 of the art of healing is a truism, but if a plebiscite limited to 

 instructed, one might almost say scientific, men were taken at 

 the present moment, it would probably enough be found that 

 the most prevalent conception of physiology is that it is some- 

 thing which is in some way an appendage to the art of medicine." 

 But without plunging "into the deep waters of the relation 

 which body bears to mind, this at least stares us in the face that 

 changes in what we call the body bring about changes in what 

 we call the mind. When we alter the one we alter the other. . . . 

 If, as the whole past history of our science leads us to expect, 

 in the coming years a clearer and clearer insight into the nature 

 and conditions of that molecular dance which is to us the 

 material token of nervous action, and a fuller exacter knowledge 

 of the laws which govern the sweep of nervous impulses along 

 fibre and cell, give us wider and directer command over the 

 moulding of the growing nervous mechanism and the mainten- 

 ance and regulation of the grown one, then assuredly physiology 

 will take its place as a judge of appeal in questions not only of 

 the body, but of the mind ; it will raise its voice, not in the 

 hospital and consulting room only, but also in the senate and 

 the school." 



ON THE SUMMIT OF MAUN A LOA. 



"r\R. H. B. GUPPY has contributed to the Pacific Commercial 

 Advertiser, published at Honolulu, an account of observ- 

 ations made during a three weeks' sojourn upon the summit of { 

 Mauna Loa in August last. 



The air at first was highly electrified. A red blanket used 



