Chemical Science. 381 



portion of the red matter was introduced into a glass tube, closed at 

 one end and heated, the other being occupied by a strip of litimus 

 paper, reddened by an acid ; a yellow vapour rose, from the sub- 

 stance which changed the red colour of the paper to blue. 



A second experiment was made with the matter of some red spots 

 found on a knife which was supposed to have been put to the same 

 use as the sabre, being found in the house where a murder had been 

 committed, and exactly the same results were obtained. 



These facts tended to strengthen the suspicions previously raised ; 

 but although a medical man did not hesitate to assert that the spots 

 were actually blood, yet they resembled rust much more than blood. 

 The experiment was therefore repeated with common rust from a 

 piece of iron found by accident in the judge's cabinet ; this rust gave 

 exactly the same result as the former, and the suspicions before ex- 

 isting were of course destroyed. 



The fact proves that rust formed within houses is capable of ab- 

 sorbing and strongly retaining the ammoniacal vapours there de- 

 veloped. It also absorbs animal vapours, for in all these experi- 

 ments vestiges of a brown oil were constantly observed on the sur- 

 face of the tube. 



M. Laugier has confirmed this result with rust found in his labora- 

 tory, and has further observed the development ultimately of sul- 

 phuric acid in the experiment. — Ann. tie Clam. xxiv. 99. 



14. New Carburettcd Hydrogen Gas. — M. Clement states as in- 

 formation which he had received directly from Mr. Dalton, that the 

 latter chemist had found a new carburetted hydrogen gas in oil gas. 

 This new gas contains twice as much carbon as nlefiant gas, and has 

 been named by Mr. Dalton super-olefiant gas. There is a great 

 quantity of it in oil gas. 



In reference to this subject we may refer our readers to a paper in 

 the Annals of P hilosophy , N.S. iii. 37, where a gas of the same che- 

 mical composition as oleliant gas, but of twice its density, is, from the 

 experiments of Dr. Henry, inferred as existing in oil gas. 



15. On Titanium, by M. Rose. — Oxide of titanium was obtained 

 pure by fusing powdered rutilite with thrice its weight of carbonate 

 of potash, dissolving the compound in muriatic acid, precipitating 

 by caustic ammonia, digesting the precipitate for a certain time with 

 hydro-sulphuret of ammonia, and then digesting the solid matter left 

 in weak muriatic acid, which leaves the oxide of titanum pure. In 

 this way only as yet can the iron be removed. The pure oxide re- 

 mains perfectly white when healed and cooled, and is then untouched 

 by acids ; fused with carbonate of potash, and then treated with mu- 

 riatic acid, it sometimes gelatinizes, though not so strongly as silica. 

 It becomes red by touching moisteued litmus, and with alkalies 



