398 Chronicles of Science. [July, 



the extremities of these detached roots. Large pieces of the resin 

 fetch a very high price even in that country. 



New Species of Jalap. — Mr. Daniel Hanbury contributes to the 

 1 Journal of the Linnean Society ' a description of a hitherto un- 

 described Convolvulaceous plant, which he names Ipomsea simulans, 

 being the plant the root of which furnishes the article known in 

 commerce as Tampico Jalap. It is obtained from Mexico, and has 

 been extensively brought into the market ; and though it is less rich 

 in resin and less purgative than true jalap, yet, on account of its 

 lower price, it has found a ready sale, chiefly in the Continental trade. 



5. CHEMISTEY. 



It has long been a disputed question whether a small quantity of 

 phosphorus improves or injures the mechanical properties of steel. 

 M. L. Grruner has carefully examined this subject, and has arrived 

 at the result that phosphorus present in steel in a quantity of from 

 0*002 to 0*003 causes the metal to be rigid; it tends even to in- 

 crease the elasticity and the resistance to breaking, but does not 

 modify the hardness. Such steel, however, is wanting in real 

 strength and toughness; it is brittle (aigre), that is to say, does 

 not withstand shocks. The general result is, therefore, that even 

 very small quantities of phosphorus present in steel do not only not 

 improve, but certainly deteriorate, its good qualities. Dr. Salet, 

 the chief assistant to Professor Wurtz, has arranged an ingeniously 

 constructed apparatus to detect the smallest possible quantity of 

 phosphorus in iron and steel, by means of the spectrum produced 

 by the combustion of the hydrogen obtained by the action of chlor- 

 hydric acid on the metal. 



Since the internal use of amylic alcohol, even in small quantities, 

 is very deleterious, the means of rapidly testing for its presence in 

 spirits and alcohol (either for pharmaceutical or scientific use) is of 

 importance. The suspected alcohol is poured into a burette, mixed 

 with its own bulk of rectified and pure ether, and also its own bulk 

 of water, and the mixture gently shaken ; the ether, on becoming 

 separated from the rest of the fluid, floats to the top, containing in 

 solution the whole of the amylic alcohol which might have been 

 contained in the alcohol or spirits under examination. The ether 

 is removed by a pipette, and on leaving it to spontaneous evapora- 

 tion, will leave behind the amylic alcohol, readily detected by its 

 offensive odour. 



The absence of oxygenated water from snow which fell at Eouen 

 has been shown by M. A. Hozeau. He has tried some very careful 

 experiments to detect the presence of peroxide of hydrogen in water 



