634 



NA rURE 



[Octohlr 29, 1896 



substance upon the blood-vessels, and not to any interference 

 with the central nervous system ; (4) the vascular dilatation 

 |iroducing the fall is not confined to the splanchnic area: (5) 

 the ililatation is brought about by lowering the excitability of 

 the ]Kripheral neuro-muscular mechanism of the arterioles ; (6) 

 this diminished excitability is in all probability chiefly limited to 

 the nervous part of the above mechanism. 



The experiments from which the above conclusions were 

 deduced were carried out in the Sorbonne Laboratory, Paris, 

 and consisted of observations of blood pressure under various 

 conditions, such as section of the spinal cord, excitation of 

 the cord after section, section of the splanchnic nerves, and 

 excitation of the peri])heral ends of these, and of the cord after 

 their section. Facsimile i^hotographic reproductions of the 

 tracings were exhibited in support of the above statements. 



A paper was read, by Ur. ]. L. Bunch, on the nerves of the 

 intestine, and the effects upon these of small doses of nicotine. 

 The method of study was one in which a small portion of the 

 intestine \\as suitably exposed and connected .so as to record its 

 movements. The following facts were brought out and illus- 

 trated by photographs of the tracings, (i) The stimulation of 

 the peripheral end of the cut vagus nerve causes no motor effect 

 as regards the portions of small intestine investigated. This 

 is so not only with small doses of atropine to eliminate cardiac 

 inhibition, but when the nerve is excited low down in the absence 

 of atropine. (2) The excitation of the peripheral end of the 

 cut splanchnic nerves may cause either contraction or dilatation 

 of the portion of intestine, but does not produce simple inhibition 

 of its movements. 



These two facts thus seem to show, in opposition to the views 

 previously held, that the vagus fibres play no part in the pro- 

 duction of intestinal movements, and that the splanchnics contain 

 augmenlor and depressor fibres for the intestinal neuro-mus- 

 cular mechanism. 



Further researches as to the splanchnic fibres showed (a) that 

 the nerve roots, the stimulation of which produce the splanchnic 

 effects, are pre-eminently those between the eighth and thirteenth 

 post-cervical nerves ; (/)) that the intravenous injection of small 

 doses of nicotine can abolish the excitatory eflects evoked by 

 stimulation of the nerve roots, although effects may still be 

 produced by excitation of the trunk of the splanchnic nerves; 

 hence the nerve-cell station appears to be in the sympathetic 

 ganglia. 



Dr. (iriinbaum followed with a communication on the effect 

 of peritonitis on peristalsis. The peritonitis was produced by 

 the injection of turpentine or other substances into the peritoneal 

 cavity. The peristalsis was observed through the shaved ab- 

 dominal wall, and in the opened cavity immersed in ph5-sio- 

 logical .salt solution at the body temperature. The peristalsis 

 of both large and .small intestine was increased for twenty-four 

 liours after the injection : it then gradually diminished, and in 

 four days resulted in complete paralysis, the large intestine 

 being paralysed before the small intestine. 



Dr. Pavy gave a communication on the glucoside constitution 

 of proteid. He drew attention to the universal recognition of 

 the importance of the glucoside in the vegetable kingdom, and 

 to the fact that such bodies as .salicin and amygdalin were 

 known to admit of cleavage into nitrogenous and glucoside 

 moieties. In the animal kingdom the mucin-like substance of 

 bile admitted of a similar cleavage. In 1894 the author 

 ]iul>lished a method for demonstrating a similar cleavage of 

 proteid. This consisted in dissolving a tissue in potash, 

 precipitating by alcohol, and treating the precipitate with 

 sulphuric acid. The gluco.se produced, varied in amount 

 according to the duration of the previous treatment with potash 

 and the strength of the reagent, hence it could not be due to the 

 conver.sion o! the glycogen of the tissue by the acid ; thus the 

 action of potash is to split off from the proteid an amylose 

 carbohydrate corresponding with the animal gum of Landwehr, 

 wliich is converted by sulphuric acid into glucose. Dr. Pavy 

 further stated his belief that a similar proteid cleavage may occur 

 in the animal body resulting in the formation of glycogen, and 

 thus of glucose, and that it is the excess of this disintegration 

 which is the essential feature of diabetes ; whilst if in the 

 process of digestion a cleavage of similar character occurs, this fact 

 must be one of extreme therapeutic importance in connection 

 with the views held as to the dietetic treatment of diabetes. 



Prof. Gotch comnninicated the results of experiments carried 

 out by Mr. Burch and himself, which determined the time 

 relations of the activity of a single nerve cell. The response 



NO. 1409, VOL. 54] 



of the electrical organ 01 Malaptertirits electric us was shown 

 to be the excitatory change in the nerve endings of the 

 .single axis cylinder which supplies it ; the reflex response 

 thus gives deductions as to the discharge of the single nerve cell 

 from which this springs. The minimal central delay was found 

 to be 'ooS" to •01", of which time 006 must be considered as 

 delayed propagation in the central fine dendrites of both 

 afferent fibre and efferent cell. The central rhythm is one 

 which is very varied, but the extreme limit t>f frequency was 

 shown to be twelve per second, and the average rate four per 

 second ; in all cases this rate was maintained for an extremely 

 short period, each group of discharges comprising only from two 

 to six members. The contrast between the reflex discharge in 

 Malaflcrin-ns with its one nerve cell was contrasted with that 

 of Torpedo, in which the very large number of cells is associated 

 with a rapid central rhythm of from 30 to 100 per second. 



On Saturday Prof. ^linot (Harvard) showed a new form of 

 microtome, prefacing the demonstration by remarks on the 

 principles of microtome construction. 



The new microtome could be adapted to cut either paraffin or 

 celloidin sections, and its construction ensured precision by 

 avoiding the following sources of error : (a) the bending of the 

 knife, which is very heavy, of the chisel type, and securely 

 clamped at both ends : (h) the yielding of the object to be cut, 

 which is fixed on a wide supporting carrier : (c) the jumping of 

 the sliding gear of the carrier ; to effect this, the knife being 

 immovable, the carrier gear is rendered as perfect as possible, 

 and allows of displacement only in the direction of its slide, and 

 the object secured upon the carriage by very rigid fastenings. 



Additional advantages are secured by a simple accurate 

 method of raising the object, a known amount, at each slide, 

 and by a device for removing the alcohol moistening the knife 

 and object so that it shall not fall upon the working gear. 



The microtome has been placed on the market by Messrs. 

 Bausch and Lamb of Rochester, New ^'ork ; its probable cost 

 being from twelve to fifteen pounds. 



Prof. Waller gave a conmiunication, illustrated by a large 

 number of facsimile photographs, as to the conditions which 

 modify the electrical res])onse of an isolated nerve to .stimulation.. 



The methoil of investigation was described : it consisted in 

 stimulating the isolated nerve by a rapid series of induced 

 currents for a very brief period, this stimulation being repeated 

 at regular intervals : the electrical response thus evoked was 

 indicated by means of a galvanometer suitably connected with 

 the nerve, and arranged so that the deflections of the galvano- 

 meter needle should be photographed on a slowly moving 

 plate. The nerve is practically submitted to a (|uestion-and- 

 answer at regular short intervals, the question being constant, 

 and the answer varying with the state of the nerve. Various 

 chemical reagents alter the character of the response : and nerve 

 records were exhibited showing (i) that chloroform is more 

 toxic than ether; (2) that carbon dioxide is typically ana;sthetic ; 



(3) that nitrous oxide is inert ; (4) that the basic is more eflective 

 than the acid moiety .of such neutral .salts as KBr. NaBr, and 

 KCl ; (5) that the response is modified by the action of various 

 alkaloids, such as morphine, atrojiine, aconitine, veratrine, 

 curarine, and digitaline. 



Dr. Mann exhibited wax models of nerve-cells magnified 

 one thousand times, and made from serial sections taken 

 through the cell in ilifferent planes. The models showed the 

 following points, in connection with the structure of the special 

 cells thus portrayed. (1) The unipolar cells of spinal ganglia 

 and multipolar cells of sympathetic ganglia are spherical or 

 oval in the central parts of the ganglion, and flattened parallel 

 to the surface at the periphery of the ganglion. (2) The distal 

 process of the bipolar cells from the spinal ganglion of the 

 guinea-pig is thinner than the proximal process. (3) The cells 

 from Clarke's Column are frequently essentially bipi>lar, i.e. one 

 axis cylinder passes upwards and another downwards, while the 

 dendritic processes are comparatively very lew and insignificant. 



(4) The motor cells in the spinal cord have wing-like processes. 



(5) In Mctlaflenirtts the cell body api>ears much broken up, 

 i)ecause of the great development of the dendritic ]5rocesses. 

 Fritsch's idea of a " Bodenplatte," from which the axis cylinder 

 is supjiosed to spring, is erroneous. 



Dr. Buchanan exhibited a number of microphotographs illus- 

 trating cell granulations under normal and abnormal conditions. 

 The evidence aft'orded by their study appeared to show that the 

 granules of leucocytes are of definite formation, and are in no 

 way analogous to secretion granules, and that whilst leucocytes. 



