102 Scientific Intelligence. * 



of dazzling white' dry sulphocyanid of ammonium are obtained, which 

 may be employed as a reagent, and for the same purpose as the sulpho- 

 cyanid of potassium. Of the 2 oz. of sulphur added, £ an oz. is left 

 undissolved. 



The behavior of the higher sulphurets of ammonium towards prussic 

 acid furnishes an admirable test for this acid. A couple of drops of a 

 prussic acid, which has been diluted with so much water that it no 

 longer gives any certain reaction with salts of iron by the formation of 

 prussian blue, when mixed with a drop of sulphuret of ammonium and 

 heated upon a watch-glass until the mixture is become colorless, yields 

 a liquid containing sulphocyanid of ammonium, which produces with 

 persalts of iron a very deep blood-red color, and with persalts of cop- 

 per, in the presence of sulphurous acid, a perceptible white precipitate 

 of the sulphocyanid of copper. 



3. Separation of Alumina from Oxyd of Iron, — Dr. W. Kuop (Jour, 

 fur Prakt. Chem., Oct. 9, 1846,) states that he has effected a complete 

 separation of these two oxyds by precipitating with sulphuret of ammo- 

 nium, washing the precipitate with water containing a little free sul- 

 phuret of ammonium, and then extracting the alumina by a solution of 

 potash which also must have a little sulphuret of ammonium in it. In 

 this way the alumina, on subsequent precipitation, is obtained on slow 





desiccation as a transparent mass, and on quickly drying and calcinin; 

 it has so perfectly a white color as to leave no doubt of its being ex- 



tremely pure. 



if minute traces of Alcohol 



Dec, 1846.) — Dr. R. D. Thomson proposes in place of the distillation 

 of a liquid suspected to contain alcohol, and trusting to the odor of 

 alcohol in the product, which is the usual mode, to resort to the use of 

 chromic acid, which as is well known, produces a characteristic emerald 

 green solution of oxyd of chromium, in fluids containing alcohol. The 

 characteristic odor of aldehyde given off from the dehydrogenation of 

 the alcohol by the chromic acid, also aids materially in detecting minute 

 quantities of spirits of wine. For this purpose a small quantity of bi- 

 chromate of potash is placed in the bottom of a conical glass contain- 

 ing a portion of the suspected fluid, and sulphuric acid is poured on it 

 by means of a tube funnel. If alcohol is present, the green oxyd will 

 soon be observed on the surface of the undissolved salt, and the char- 

 acteristic odor of aldehyde will speedily be perceptible. 



>/ 



VV 



P 



100-105; Chem. Gaz., March, 1847 .)— Pelouze, and especially Bernard 

 and Barreswil, have shown with certainty the absence of free muriatic 

 acid in the gastric juice. The author has obtained the same result, 

 and at the same time he has indisputably proved the presence of free 

 lactic acid. To obtain the gastric juice of dogs in the greatest state of 

 purity possible, these animals were kept without food for from twelve to 

 sixteen hours, and then fed from ten to twenty-five minutes before death 

 with bones freed as perfectly as possible from skin and fat. Immediate- 

 ly after they were killed, the stomach was tied at the cardia and pylorus, 

 and removed from the body. It was then opened by an oblique incision 



near 



