230 ANNUAL OF SCIENTIFIC DISCOVERY. 



litre ; 10 c.c. of this solution arc taken for each assay, and 4 c.c. 

 of benzol arc acUkid. — J. de Pluirmacie. 



Detection of Alcohol. — M. Lichen adds to the liquid suspected 

 to contain alcohol a small qnantity of iodine and a few chops of 

 caustic potash or soda. On heating, bnt not boiUng, the mixtnre the 

 presence of alcohol is denoted bv a very characteristic yellowish 

 prcci})itate of iodoform. It is possible in this way to detect one- 

 t\yo-thousandth part of alcohol dissolyed in water. — Mon. Sci. 



Testing Glycerine for Sugar and Dextrine. — To 5 drops of the 

 glycerine to be tested add 100 to 120 drops of water, 3 to 4 

 centigrams of ammonium-molybdate, one drop pnre nitric 

 acid {'2o percent.), and boil for about a minute and a half. If 

 any sugar or dextrine be present, the mixture assumes a deep 

 bine co]or. — Pol i/t. Notizhl. 143, 1868. 



Detection of Phosphorns. — According to Dr. Schonn, of Stettin, 

 when inorganic combinations of phosphorus and phosphates are 

 ignited (after being preyiously well dried) with small qnantities 

 of pure magnesium (best is powder), phosphide of magnesium is 

 formed, and the fused mass, on being moistened with water, will 

 disengage phosphuretted hydrogen gas, which, in many cases, will 

 be found to be the spontaneously intlammable variety of this 

 compound. Phosphorus may thus be detected in organic sub- 

 stances, which, however, should be previously calcined. — Zeitcsh. 

 f Anal. Ch. 



Test for Nitrates and Chlorates. — To one c.c. of pure concen- 

 trated sulphuric acid is added one-half c.c. of a solution of sulphate of 

 aniline, prepared by adding 10 drops of the aniline of commerce 

 to 50 c.c. of dilute sulphuric acid (1 to 6). If a glass rod be 

 dipped in the substance to be tested, and then into the mixture, 

 the presence of nitric acid, or of a nitrate, causes red streaks to 

 appear in the path of the rod, or if the quantity of nitric acid be 

 considerable, a tint varjing from carmine to a deep red will per- 

 vade the mixture. The presence of a chlorate is indicated by a 

 blue coloration. — Cheni. News. 



Chlorate of Potassium as a Blow-pipe Test. — In the "Neues 

 Jahrbuch fiir Pharmacie " M. Landauer enumerates several in- 

 stances in which chlorate of potassium may be made very useful 

 biifore the blow-pipe in the search for certain metals. This salt, 

 giying up at higher temperatures some of its oxygen to certain 

 metals, becomes itself colored by the oxides of those 

 metals. From ?>on and its compounds it receives a flesh color; 

 from lead a pale brown ; from copper a shade of light or dark 

 blue, in some cases so deep even as to be nearly black. Manga- 

 nese imparts to the alkaline salt a purple of variable intensity, 

 and nickel (sesquioxide = Nio O.-,) turns it to black. The reac- 

 tion is best performed in a tube closetl at one end, 5 or 6 

 inches long by one-fifth to a quarter of an inch in diameter, into 

 which is introduced a mixture of equal parts of the substance 

 under examination, and of chlorate of potassium, previously 

 rubbed fine with a f i w drops of alcohol and then carefully dried. 

 The tube is heated gradually, at lirst over the lamp, and linally by 

 means of the bl«)w-pipe. 



