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V. Proccedi7igs of Learned Societies. 



ROYAL SOCIETY. 

 May 5. — A PAPER was read, " On the effect of Water, raised to 

 -iJ^ Temperatures moderately higher than that of the At- 

 mosphere, upon Batrachian Reptiles." By Marshall Hall, M.D.,&c. 

 Dr. Edwards had found, by a series of experiments, that the batra- 

 chian reptiles, when immersed in hot water, live for a shorter time m 

 proportion as the temperature of the water is higher ; and that at 

 \0S° of Fahrenheit they die almost instantaneously. The author of 

 the present paper observes, that the extinction of life in these cases is 

 owing to a cause of a more immediately destructive agency than the 

 mere suspension of respiration : he finds that if only the head of the 

 animal is placed under water of 120°, the animal struggles, but soon 

 ceases to move ; but if the spine as well as the limbs be immersed, 

 convulsions supervene, and the muscles become rigid : in both cases 

 the action of the heart continues. If one of the limbs, which after the 

 extinction of sensibility still remains flexible, be separated from the 

 body, and placed in water of 120", its muscles contract and become 

 rigid; this effect taking place first in the superficial, and next in the 

 deep-seated muscles. When the nerve, separated from the other 

 parts, was alone placed in hot water, the muscles were not affected : 

 and when the muscles had been made to contract by hot water, they 

 were no longer capable of being affected by irritations applied to the 

 nerve. The heart removed from the body, and placed in hot water, 

 gradually contracted and remained rigid. Hence the author concludes 

 that the death of the animal, when occasioned by the sudden applica- 

 tion of heat to the surface, is not owing to asphyxia, but to a posi- 

 tive agency, destroying the functions of the nervous and muscular 

 systems ; the muscles of involuntary motion being affected in like 

 manner with those of voluntary motion. 



A paper was read, entitled an "Account of a new mode of pro- 

 pelling Vessels." By Mr. Wm. Hale. Communicated by Richard 

 Penn, Esq. F.R.S. 



The author ascribes the want of success which has hitherto attend- 

 ed all attempts to propel vessels by a discharge of water from the 

 stern, to the injudicious plan of the apparatus employed, and not to 

 any defect in the principle itself : for he considers that the reaction 

 upon the vessel from which a volume of water is thrown, depends in 

 no degree on the resistance it meets with from the medium into 

 which it is ejected, but simply upon the momentum given to the mass. 

 The author proposes to accomplish the object of propelling water by 

 means of an instrument having the form of an eccentric curve, re- 

 sembling the spiral of Archimedes, made to revolve on an axis. The 

 resistance offered to the water in wliich it is immersed results from 

 the different distances of the two ends of the spiral propeller from the 

 axis. Tills propeller acts in a box having also a somewhat spiral 

 form, and the space between the two ends of the spiral, after descri- 

 bing one turn, is open to allow of the exit of the water driven out 

 by the propeller. The bottom of the box has a circular aperture, of 

 N. S. Vol. 10. No. 55. July 1831. G which 



