1871J (127) 



PROGRESS IN CHEMISTRY, 



(Including Chemical Science, Technology, and Mineralogy). 



CHEMICAL SCIENCE. 



To the list of earth-eating people the Javanese must be reckoned ; and 

 Professor C. W. C. Fuchs has given a full account of the edible earth in use by 

 this people. One deposit possessing an intensely red colour, exists in the 

 neighbourhood of Sura Baja, between strata referable to the time of the latest- 

 tertiary. This earth is formed into thin cakes, having a diameter of from 1 to 

 ih inches ; it is then dried over an open fire, and in this condition is brought into 

 the market. It is perfectly smooth to the touch, and is composed of materials in 

 the finest state of subdivision. By a chemical analysis it is found not to 

 contain the slightest trace of an organic substance. It is apparent that the 

 earth consists of a clay rich in iron, in which is still retained small quantities 

 yet undecomposed, of the minerals from which it derived its origin. Upon 

 rubbing it, not the slightest grittiness is perceptible, and on being moistened 

 with water it forms a smooth and unctuous mass. The enjoyment derived 

 from eating it seems to reside in the similarity of the sensations it produces 

 with those derived from the eating of fatty substances. In many parts of 

 Wurtemburg the quarrymen have the habit of eating the smooth, unctuous 

 clay which collects in the fissures of the rocks. The term " Mondschmalz," 

 which they apply to it, would seem to refer to the enjoyment they experience 

 in the process of eating. 



Dr. Hofmann has discovered a most delicate test for chloroform, based upon 

 the fad that, when chloroform is mixed with aniline and an alcoholic solution 

 of caustic soda, a very strong reaction takes place, and isonitrile is generated, 

 which is readily recognised by its peculiarly characteristic smell ; this reaction 

 is so delicate that, when 1 part of chloroform is mixed with from 5000 to 

 6000 parts of alcohol, the first-named substance is readily detected. 



Professor Seely has made the discovery that anhydrous liquid ammonia has 

 a solvent power upon certain metals, and he has actually succeeded in obtaining 

 a solution of sodium in liquid ammonia. This solution presents all the 

 physical characteristics of a true solution. On evaporation, the sodium is 

 gradually restored to the metallic state in the same continuous manner in 

 which the solution has been affected. The colour of the solution is a very 

 intense blue, of high tinctorial power. 



A very simple and powerful method of resolving minerals in analysis has 

 been devised by Dr. Schonn. A steel crucible is heated over a lamp ; into this 

 is projected a few pieces of metallic sodium, and afterwards the finely-divided 

 and dry mineral is added. The crucible is then covered and heated to redness. 

 As soon as the the reaction is finished the contents of the crucible are allowed 

 to cool, and water is cautiously added, sufficient for the purpose of filtration. 

 The fused mass is then thrown upon a filter and thoroughly washed. In the 

 filtrate will be found the electro-negative constituents of the mineral combined 

 with the sodium, such as sulphur, cyanogen, chlorine, chromic acid, silica, 

 molybdic and tungstic acids, and such oxides as are soluble in soda-lye. On 

 the fiker will be found the metals and their oxides, also the lower oxides of 

 titanium, molybdenum, tungsten, and possibly silica and alumina. The 

 contents of the filter and the solution in the filtrate can be further treated 

 accordingto the order of analysis. In this way all minerals can be readily 

 resolved, and their constituents determined either qualitatively or quantitatively. 



In a paper on organic matter in water, Mr. C. Heisch indicates a very 

 simple test for the presence in water of organic matter arising from sewage 

 contamination, which consists in adding ten grains of pure loaf sugar to six 

 ounces of the suspected water, and setting the bottle aside for a few days in a 

 warm place exposed to light, when, in the event of a sensible quantity of this 



