THE NEW YORK JOURNAL OF PHARMACY 



of an alkali inanganate shows the pres- 

 ence of Mn. 



NaXOg + MnO(OH)2 + KNO,= 

 Na.MnO, + KNO, + CO, -\-n,0. 



The delicacy of this test is increased 

 through the use of a sodium carbonate 

 bead. A trace of the substance tested 

 is heated in the bead to fusion and with 

 the hot bead is quickly touched a little 

 powdered KCIO,, and the bead allowed 

 to cool without further heating-. The 

 green blue manganate is unstable ; its 

 solution rapidly changes in color. Fer- 

 ric hydroxide, usually present with 

 MnOfOH)^, does not interfere. 



2. — Oxidation to (MnO^ — ) in a 

 Solution. — The formation of perman- 

 ganic acid takes place when Aln or one 

 of its inorganic compounds (except 

 chloride) is heated with 25% HNO., 

 and some lead peroxide. A small quan- 

 tity of the sample free from organ'c 

 matters and chlorides is placed in a 

 small porcelain dish, the acid and PbO. 

 added, and the mixture gently boiled 

 during 2 to 3 min. After the black par- 

 ticles in suspension have deposited, an 

 intense purple color of the acid solution 

 indicating the presence of Mn is observ- 

 able. 



^lnO(OH), + 3Pb02 + 6HNO3 = 

 2HMn04 + aPbCNOg), + 4H2O. 



The PbOo must, of course, be Mn 

 free. A large proportion of iron ob- 

 scures the test. The presence of organic 

 matter and of chlorides interferes, for 

 the organic compounds are oxidized by 

 the HMn04 while the chloride yields 

 with it free chlorine : 



2HMnO, + I4HC1= 

 2Mnri., + 8H2O + 5 CI,. 



3. — Oxidatini to MnO.. — In an alka- 

 line solution a number of metals yield a 

 black precipitate with oxidizing agents; 

 in a strongly acid liquid only Mn forms 

 a black colored compound. Chlorides 

 interfere and must be removed before 

 testing. The solid or solution is boiled 

 with fc) HNO3 and a little KQO,, 

 added in portions, in a porcelain dish. 

 The formation of a black precipitate of 

 MnOo indicates the presence of Mn. 



4. — Borax or M eta phosphate Bead 

 Test. — Heated to fusion in the oxidizing 

 flame, Mn+ compounds color the bead 

 amethyst red. In the reducing flame 

 the color is discharged provided the 

 heating is sufficiently prolonged. 



In the 3rd group precipitate, MnO- 

 (OH)o or MnOo is left undissolved by 

 NaoO, and NaOH with which the pre- 

 cipitate is treated. Unless a large 

 amount of iron is preesnt, the residue is 

 dark brown or black in color and is then 

 tested for :\Tn by tests i or 2, which 

 serv^e to detect even a minute amount of 

 the element. 



RADIUM. . 



By Fannie Hart, Ph. G.* 



Radium, discoverd by Prof, and Mme. 

 Curi- in 1899, is closely related to 

 Barium. Its chloride is separated from 

 Barium chloride by repeated fractional 

 crvstalization. 



Radium shows a characteristic spec- 

 trum and colors the Bunsen flame car- 

 mine red. 



Radium salts are luminescent and 

 excite phosphorescence in a variety of 

 compounds. 



*Miss Hart is a graduate of N. Y. C. P., 

 '10. Read before the Women's American 

 Phar. Ass'n. 



