168 Scientijic Intelligence. — Medical Chemistry. 



nia. If the acid be contained in syrujDs or other highly colored flu- 

 ids, it is recommended to add two or three drops of a solution of pot- 

 ash to a small portion of the fluid and place in it a strip of unsiz- 

 ed paper, which after a few minutes will acquire a reddish yellow col- 

 or ; dry it in the air, and then touch it with a solution of trito-sulphate 

 of iron, when all the parts touched will become of a greeenish blue. 



With respect to the hydro-cyanic syrup, it is enough to dilute it 

 with distilled water, and to add nitrate of silver in excess ; all the hy- 

 dro-cyanic acid will be precipitated, without the addition of any for- 

 eign matter to the cyanuret of silver. 



The hydro-cyanic syrup of the French Codex, composed of nine 

 parts of syrup of sugar, and one of the medicinal acid of .9 is an 

 excessively strong medicament, which should be administered only in 

 drops ; for a dose of two or three grs, occasions the death of the 

 most robust man in from twenty to forty minutes. 



The means hitherto employed to combat the eifects of this poison 

 are, principally, the following : ammonia, concentrated infusion of 

 coffee, spirits of turpentine, bleeding, affusion of cold water, and chlo- 

 rine. These several methods were carefully tested by direct and re- 

 peated experiments upon dogs, and the result is that not much confi- 

 dence can be placed in any of them except chlorine. This remedy 

 proved surprisingly efficacious. It was first tried as a prevention 

 against the vapors of the an-hydrous acid in the hospital of St. Louis 

 by M. Simeon, the apothecary of that establishment in the month of 

 April last. Finding that gaseous chlorine counteracted the unpleas- 

 ant efiect of the hydro-cyanic vapors, he put two drops of the liquid 

 acid prepared by Vauquelin's method, on the conjunctiva of a cat, 

 which in a few seconds produced all the symptoms of a fatal poison. 

 After a minute and a half, a weak solution of chlorine, was presented to 

 the nose of the animal, which appeared at first to produce no effect, 

 but, two minutes after, the cat, which seemed not to have breathed 

 till then, made a deep respiration, the pulsations of the heart became 

 stronger and more regular, he opened his mouth, and put out his 

 tongue as if to seek the chlorine. 



In three fourths of an hour his restoration was still doubtful, al- 

 though the chlorine was constantly applied to his nostrils and the sur- 

 rounding parts bathed with it. In half an hour more, he was able to 

 stand upright and take a few steps. In the course of six hours from 

 the commencement, his walk was easy and he appeared to be per- 

 fectly recovered, except a slight trembling which did not cease under 

 twenty four hours. 



