186 ANNUAL OP SCIENTIFIC DISCOVERY. 



TABLE TURNINGS. 



Much interest has "been excited in Paris by a paper of M. Chevreul's 

 to the Academy of Sciences, taken from the introduction of a work now 

 in press, in which he treats of the phenomena of table turnings. This 

 distinguished chemist does not confine himself to this subject alone, but 

 connects with it the "exploring pendulum" and "divining rod," and he 

 endeavors to reduce these phenomena to certain rational facts. In 1812, he 

 noted the phenomena of the pendulum in a letter to Ampere, and showed 

 that the pendulum movement was produced only when the eye of the 

 experimenter was fixed on the instrument ; and he endeavored to prove 

 thereby that the motion was due to a play of the muscles. Some members 

 of the French Academy objected to the consideration of a subject con- 

 nected to such an extent with supersitition. M. Chevreul believes that 

 the question may be treated without going out of the domain of true 

 science, agreeing with Arago and Faraday, and regards it not unworthy 

 of a man of true science to occupy himself with any demonstrated facts 

 in order to search out their relation to other facts. 



DEFINITION OF THE BOILING POINT OF WATER. 



The following report was made at the last meeting of the British 

 Association by the " Kevv Committee : " 



"Your Committee, at the last meeting of the Association, were requested 

 to furnish a report on the definition of the boiling point of water as at 

 present adopted in this country for the thermometric scale. This has 

 already been considered by the Commissioners appointed by Government 

 to construct standard weights and measures ; and in the report they have 

 presented to Government during the present year, they have defined 212 

 upon Fahrenheit's scale to represent ' the temperature of steam under 

 Laplace's standard atmospheric pressure, or the atmospheric pressure 

 corresponding to the following number of inches in the barometric reading, 

 reduced to 32 F., 29.9218 -|- 0.0766 x cosine (2 latitude) + (0.00000179 

 X height in feet above the sea.') Your Committee recommend that this 

 definition be adopted." 



CHEAP MICROSCOPE. 



There is a man who sometimes stands in Leicester Square, London, who 

 sells microscopes at one penny each. They are made of a common pill- 

 box ; the bottom taken out, and a piece of window glass substituted ; a 

 small hole is bored in the lid, and therein is placed a lens, the whole 

 apparatus being painted black. Upon looking through one of these 

 microscopes, I was surprised to find hundreds of creatures, apparently the 

 size of earthworms, swimming about in all directions ; yet on the object 



