260 ANNUAL OF SCIENTIFIC DISCOVERY. 



were quite yellow, and a bitter taste felt in the mouth, without perceiving an 

 unfavorable symptom." 



BASIC NITRATE OF BISMUTH AS A REAGENT FOR GRAPE SUGAR. 



BY PROF. BOTTGER. 



In testing urine for example, for sugar, if one volume of urine be boiled 

 with an equal volume of a solution of one part of crystallized carbonate of 

 soda in three parts of water, and a very small quantity of basic nitrate of bis- 

 muth be added to it, the latter becomes gray by reduction, if grape sugar be 

 present. Cane sugar does not possess this property, and none of the other 

 bodies occurring in the urine blacken the bismuth salt. Journ. fur Prakt. 

 Chcmie, Ixxi. p. 431. 



NEW TEST FOR MANGANESE. 



Bottger has given us a new reagent for manganese. He states that the 

 minutest quantity may be detected by the chlorate of potash. In order to 

 detect it, throw a small quantity of the material suspected to contain man- 

 ganese into a test-tube, which already contains the chlorate of potash in a 

 state of fusion. After the combustion has entirely ceased, and the tube is 

 cold, a peach-blossom residue will be left if there has existed the smallest 

 quantity of manganese. By means of this reaction, Bottger has discovered 

 manganese in boxwood, beech, cork, in the iodine of commerce, tea-leaves, 

 and several articles of food. 



ON THE DETECTION OF ADULTERATIONS OF THE ETHEREAL OILS. 



In 1854, an eminent drug house of Dresden offered a prize for the solution 

 of the following problem : To find a certain and easily applicable method 

 for the detection of oil of turpentine in the most important ethereal oils. 

 This problem was solved by, and the prize awarded to, Air. G. S. Heppe, of 

 Leipsic. 



Though it was not the good fortune of Mr. Heppe to discover a substance 

 which characterizes the oil of turpentine exclusively, yet we are enabled, by 

 the test used by him, successfully to demonstrate the same in most of the 

 oils containing oxygen, those oils containing no oxygen, as ol. Juniperi, 

 Citri, etc., therefore excepted. This reagent consists in nitro-prussid copper, 

 and the mode of its application is as follows : 



A so-called eprouvette (a small glass tube, open at one end), which ought 

 to be perfectly clean and dry, is filled one-fourth, or at the most one-third, 

 with the suspected oil, then 2-5 milligrammes (about as much as a small pin- 

 head) of finely powdered and perfectly dry nitro-prussid copper is added, and 

 well shaken up ; then the tube is heated over a spirit-flame up to the boiling- 

 point of the oil, and, after one ebullition, is drawn away, and set aside to 

 settle. If the oil was free from turpentine, then the precipitate will be, 

 according to the oil used, either black, brown, or gray, and the oil itself be 

 more or less of a darker color than originally. But if the ethereal oil con- 

 tained turpentine, then the precipitate will be either green or bluish-green, 

 and the oil either colorless or of a pale-yellow hue. The longer the oil is 

 left for settling, the more perceptible the color of the oil or of the precipitate 

 will be. 



