106 Scientific Intelligence. 



2. On a New Method for the Detection of Bromine and Iodine; by 

 Dr. G. L. Cantu, (Chem. Gazette, Oct. 1st, 1848.) — The water to be 

 examined is evaporated to a small bulk; pure carbonate of potash (the 

 absence of bromids and iodids in which, has been ensured by washing 

 repeatedly with alcohol) is then added in slight excess to precipitate 

 earthy salts which may be present. After boiling for some time, the 

 liquid is filtered and evaporated to dryness; the residue is now pow- 

 dered and digested in alcohol, sp.gr. *830, which dissolves any bromids 

 or iodids that may be present. The alcoholic solution is evaporated to 

 dryness, and gently ignited to destroy the organic matter which is gen- 

 erally present; a few drops of dilute acetic acid are now added so as 

 to be in slight excess, taking care to neutralize a trace of carbonate of 

 potash taken up by the alcohol. It is now again evaporated to dryness, 

 care being taken not to heat it so much as to decompose the acetate. 

 The residue is finally dissolved in a very little water and mixed with 

 two or three drops of a weak solution of starch recently prepared. This 

 being done, a small portion of the test-liquid which consists of a mix- 

 ture of ten parts of sulphuric acid of 66° (sp. gr. 1*767), and one of 

 nitric acid of 25° (sp. gr. 1-197), is placed in a glass with a narrow 

 base; the solution of the saline residue is then poured very gently 

 down the side, so as to rest upon the test-liquid without mixing with it. 

 If iodids or bromids existed in the water, and their coexistence is almost 

 constant, there will quickly appear two zones in the saline solution, one 

 of a clear topaz-yellow sometimes inclining to green, (bromine,) and 

 the other of a blue color, (iodine,) floating above it. 



[I have had occasion to employ this test in the qualitative examina- 

 tion of mineral waters, and believe that it leaves nothing more to be 

 desired in testing for bromine and iodine. I may remark in passing, 

 that having had occasion to analyze minutely a great number of saline 

 waters in this country, I have scarcely ever failed to detect these two 

 elements, although the amount of iodine, always small in proportion to 

 the bromine, is often exceedingly minute.] T. S. Hunt. 



3. Researches on the Compounds of Titanium; by G. M. Ebelman, • 

 (Ann. de Chem. et de Phys., xx, p. 385.) — By passing a mixture of 

 pure hydrogen gas and the vapor of the perchlorid of titanium, through 



a glass or porcelain tube heated to redness, a new compound was de- 

 posited in large dark violet-colored shining scales, much less volatile 

 than the perchlorid, a portion of which undecomposed is deposited in 

 the colder portions of the tube. It is readily decomposed when heated 

 in the air, into oxyd of titanium (titanic acid) and perchlorid. It is 

 deliquescent and yields, with water, a violet-red solution, which when 

 evaporated, evolves hydrochloric acid, and leaves a blue oxychlorid. 

 Ammonia gives in the solution a dark-brown precipitate, which is un- 

 doubtedly the sesqui-oxyd; by exposurn to the air it becomes black, 

 then blue, and finally white ; if air is excluded, hydrogen gas is evolved 

 from the decomposition of the water, and the same changes in color 

 take place. The formation of the blue compound by the decomposition 

 of water shows it to be intermediate between the sesqui- and per-oxyd, 

 (perhaps Ti 3 O^ analogous to magnetic oxyd of iron.) The analysis of 

 the violet chlorid showed its composition to be Ti 2 Cl 3 . Its solution 

 red ices salts of gold, silver and mercury to the metallic state, and 

 co* verts the persalts of iron into protosalts, titanic acid being formed. 



