156 REPORT — 1876. 



5. That the special action of vanadium on the function of respiration is to cause 



(a) A stimulation, followed by 



{b) A depression of respiration, the latter being not continuous, but 

 intermittent. 

 Both effects are considered to be due to an action of the poison upon the respi- 

 ratory nervous centre. 



0. That the special action of vanadium on the function of circulation is to cause 

 (ff) A diminution of blood-pressure, which is not continuous, but inter- 

 mits during the operation of the poison ; 



(b) A disappearance of I'espiration-curves ; 



(c) A diminution and irregularity of pulse, which is also intermittent. 

 The results are considered to be due to an action of the poison on the vaso-motor 



centre and on the intracardiac nervous mechanism. 



7. That, although muscles and nerve-trunks speedily die when immersed in even 

 dilute solutions of a sodium salt of vanadium, yet vanadium is not rightly to be 

 called a muscle- and nerve-poison, since frogs which have been poisoned by sub- 

 cutaneous injection of vanadium still possess nerves and muscles which, in irrita- 

 bility or in power of doing work, are quite normal. Nevertheless vanadium attacks 

 the nervous centres of the spinal cord and medulla oblongata. 



Observations on the Phi/siologiccd Action of Chromium. 

 By John Pkiestley. 



The author experimented with guinea-pigs, rabbits, and frogs, injecting solutions 

 of neutral chromate of sodium (Na^CrO,,) beneath the skin or into tlie veins. lie 

 concludes : — 



1. That -1 to -3 grm. CrOj, in the form of the above-named salt, is a powerful 

 poison for rabbits and guinea-pigs. 



2. That death is preceded by sp.asms and violent retching, which commence a 

 few minutes after injection of the poison. Spasms are succeeded by paralysis of 

 motion and, in frogs, abolition of reflex action. 



3. That the blood-pressure first rises and then falls, the fall continuing until death. 

 Further, that after the fall has become marked the pulse suddenly becomes ab- 

 normal, stopping for the space of a beat or two at irregular intervals, which are 

 occasionally of considerable length, the pulse becoming regular again during the 

 intervals. The author believes that this irregularity of pulse is due to an action 

 on the vagus nervous centre. 



4. That the alimentaiy mucous membranes are the seat of extensive congestion 

 and ecchymoses. 



5. That the kidneys become congested. 



6. That muscles and nerve-trunks and extremities remain sensiblv normal. 



The Termination of the Nerves in the Vestihide and Semicircular Canals of 

 Mammals. By Ukban Peitchaed, M.D., F.B.C.S., Aural Surgeon to 

 King's College Jfosjjital, Lecturer on Animal Physiology at King's College. 



The author gave the results of his investigations into the structure of the ner\-e 

 epithelium, as it is called, which contains the termiual distribution of the acoustic 

 nerve. 



The membranous labyriutli is composed of three layers — externally some loose 

 connective tissue, then a distinct layer of dense connective tissue"^ (the tunica 

 propria), and lying on this a single laj-'er of tessellated epithelium. At the acoustic 

 spots, where the nerve is distributed, this membrane is firmly adherent to the 

 osseous wall, and the epithelial layer becomes transformed into nerve epithelium. 



In the saccule and utricle these spots are termed the macuhe acusticre, and in 

 the three arapullaj the cristse acustica?, the latter being raised into a kind of ridge. 



The nerve epifhclium. — Max Schultze described this structure as consisting of 

 three elements— a deep layer of nuclei, a superficial layer of cylindrical cells, and 

 between them numerous filiform cells. 



