564 Chronicles of Science, [Oct., 



An optically-neutral sugar has been prepared by E. J. Mau- 

 mene. He mixes equal parts of pure sugar-candy and neutral 

 nitrate of silver, both previously dissolved in water, and evaporates 

 the mixture upon a water-bath. He states that neither at 100°, 

 nor even at 140°, any decomposition ensues or any reduction of 

 silver takes place, provided the sugar be free from inverted sugar. 

 The sugar, rendered syrupy by the process described, is optically 

 neutral. The silver-salt is separated from the sugar by means of 

 pure chloride of calcium, and the nitrate of lime is separated from 

 the sugar by the addition of alcohol and placing this mixture under 

 a bell-jar along with quick-lime. In this manner, by slow concen- 

 tration, two layers of different specific gravity are formed: the 

 upper being an alcoholic solution of nitrate of lime, the lower a 

 viscous saccharine liquid. The former is poured off, and, by a 

 slight washing with cold distilled water, the thick sugar solution 

 is freed from any adhering nitrate of lime. The sugar obtained 

 does not crystallize. 



In a lengthy paper on the optical properties of benzyl, and of 

 some substances belonging to the camphor groups, in the crystal- 

 line state and in solution, M. des Cloizeaux describes a series of 

 experiments, the chief results of which are that benzyl and perio- 

 date of soda possess, when in the solid crystalline state, strongly- 

 marked rotatory powers, and are devoid thereof in the state of 

 solution. Quartz, chlorate, and br ornate of soda act the same. 

 Sulphate of strychnia possesses rotatory powers in crystals as well 

 as in solution, while ordinary camphor, patchouli camphor, cam- 

 phor of oil of mint, Borneo camphor, tere camphor, and monchlor- 

 hydrate of turpentine possess rotatory power when in solution, but 

 not in the crystalline state. 



0. Loew has found that when aqueous sulphurous acid is ex- 

 posed in sealed tubes to the action of sunlight, it is gradually 

 reduced to sulphur, but the oxygen is not liberated, another part 

 of the acid having been oxidized by it to sulphuric acid. 



According to J. Girard, who has made several voyages on the 

 Mediterranean Sea, its peculiar colour, ranging from pale blue 

 through all shades of that colour to black (viz. when seen from a 

 ship's deck), is entirely due to the mode of reflexion of the sun's 

 rays according to the lower or higher position of that luminary 

 above the horizon, so that at mornings and evenings, when the rays 

 fall more obliquely and pass therefore through a larger bulk of 

 water the colour is deepest, provided it be at such distances from the 

 shore that the depth of the sea is sufficiently great. 



At one of the recent meetings of the Franklin Institute, Pro- 

 fessor Morton exhibited in the lantern some pictures on gelatine 

 prepared in a manner devised by Mr. Holman. For this purpose 



