468 Scientific Intelligence. [June, 



name and designation, that the Society may know how to ad- 

 dress the successful candidate. 



3. No paper in the hand- writing of the author will be re- 

 ceived ; and if the author of any paper shall either directly or 

 indirectly discover himself to the Committee of papers, or to 

 any member thereof, such paper will be excluded from all com- 

 petition for the medal. 



4. All the dissertations, the successful one excepted, will, if 

 desired, be returned with the sealed packets unopened. 



5. The prize medal will be presented to the successful can- 

 didate, or his representative, at the Anniversary Meeting of the 

 Society in March 1825. 



The subject of the Dissertation to be offered for the Prize 

 Medal for March 1825, is, " The Pathology and Treatment of 

 Periodical Asthma." 



Article XIV. 



SCIENTIFIC INTELLIGENCE, AND NOTICES OF SUBJECTS 

 CONNECTED WITH SCIENCE. 



I. Hydriodale of Potash. 



M. Taddei proposes the following method of preparing this salt : 

 dissolve iodine in spirit of wine, and pour repeatedly a solution 

 of hydrosulphuret of potash into the solution of iodine ; the fluid 

 becomes turbid, and changes from the blackest brown to a ches- 

 nut colour, and this, diminishing in intensity, gradually becomes flesh 

 coloured, and afterwards milk white. At this period the conversion 

 of the iodine into hydiiodic acid is effected ; and if the liquid does not 

 become turbid on the addition of a few drops of hydrosulphuret of 

 potash, the operation may be regarded as complete. After standing 

 a few minutes, the precipitated sulphur is to be separated by decan- 

 tation or by the filter, the mixture is then to be distilled to procure 

 the alcohol employed, and the residuum is to be evaporated to dry- 

 ness in an open vessel to obtain the hydriodate of potash. — (Giornale 

 diFisica, etc. 1823.) 



II. Action of Hydrocyanic Acid on Vegetable Life. 



M. Becker has made many experiments, from which it results that 

 hydrocyanic acid, prepared according to Vauquelin's process, destroys 

 vegetables nearly in the same manner that it does animals. Seeds 

 soaked in this acid are equally killed by it, and lose their germinat- 

 ing power. Delicate plants are killed sooner than those which are 

 stronger. — (Journal de Pharmacie, p. 174, April 1824'.) 



III. Diurnal Variation of the Barometer. 



The Edinburgh Philosophical Journal, conducted by Dr. Brewster ; 

 the Journal of the Royal Institution of Great Britain, conducted by 

 Professor Brande ; the Bulletin Universal des Sciences et de lTndus- 



