182 iJr. Oliver on the Frussic AciA. 



during the niglit, the air bubbles might have been equally 

 diffused through the ice, but, as the nights (according to the 

 usual course of things) are marked by a rather sudden and 

 commonly by a considerable increase of cold, the layer of 

 water about to congeal, was made suddenly to evolve the 

 dissolved air, and this, from its levity, rising rapidly through 

 the as yet fluid water, necessarily collected with considera- 

 ble regularity, just at the bottom of the last formed layer 

 of ice, but still completely within the new one. 



It was observable that the layers of air bubbles were well 

 defined and regular on the upper side, but irregular on the 

 lower — many bubbles being below the general level, and 

 appearing to have been arrested before they had time to 

 arrive at the upper surface of the water. 



MEDICAL CHEMISTRY. 



.Art. XXVI. — On the Hydrocyanie or Prussic Acid, by 

 B. Lynde Oliver, M. D. of Salem, Mass. 



Insaniim quiddam esset, et in se contrarinm, existiinare ea, quse adliuc 

 {.luiKjuani iaclasujit, fieri posse nisi per modos adhuc nunquam lentatos. 



Bacon JVov. Organ. Jlphor. VJ. 



TO PROFESSOR SILLIMAPT. 



Sir, 



Having read in your excellent Journal of Science and 

 Arts, a very interesting paper on the Prussic Acid, in which 

 an. invitation is given to physicians to transmit their remarks 

 on the trial they may have made with this active agent; 1 

 now beg leave to avail myself of it, and hope that yovi will 

 pardon my prolixity. 



It is now more than nine years since I gave an attention 

 to this subject,^ nor did I then know, that the Prussic acid 



* In Dr. Thatclier's interesting work, entitled, Observations on Hydro- 

 phobia, p. 280, the following: note occurs : " The cherry laurel is the same 

 as tlie laiiro-cerasus, of which we have a pai-ticular account in Cullen's 

 Materia Medica, as being' one of the most deadly of all the vegetable poi- 

 sons. A ca.utious use of it has been attempted in some diseases, and my 

 friend and correspondeat, Dr. B. Lyude Oliver of Salem, has recently em- 



