840 Transactions of the American Institute, 



the quantity present in the roots greater than that which had been 

 supplied to the plant. 



EXTRACTION OF OILS. 



It is said a large number of German houses are extracting oils 

 by means of bisulphide of carbon. The quantity of oil obtained 

 by it is reported to be from five to eight per cent more than can be 

 made by the hydraulic process; and as the refuse contains more 

 nitrogen than the ordinary oil-cake, it is more valuable as a manure. 



GAS FROM A VOLCANO. 



M. J onqu6 succeeded, after great trouble, in collecting some of 

 the gas which arose from the sea during a volcanic eruption at the 

 Azores, in June last, which he has since found to be free from car- 

 bonic acid, and rich in oxygen. 



SINGULAR EFFECT OF LIGHTNING. 



Sir David Brewster has published a description of the manner 

 in which a stack of hay was struck by lightning in Forfarshire. 

 The stack was on fire, but was extinguished before much of it had 

 been consumed. On examining the stack, a circular passage was 

 observed, which extended to the bottom, and terminated in a hole 

 in the ground. In the hole was found a foreign substance, which 

 proved to be silex, obviously formed by the fusion of the silex 

 contained in the outer coating of the hay. It had a greenish tinge, 

 and contained burnt portions of hay. 



VENTILATION. 



The House of Commons required during last session 2,500,000 

 cubic feet of air per hour for its proper ventilation. The original 

 plan of taking the supply of air from a gi'eat height, viz: from the 

 clock tower, has been given up, because it was found that London 

 air at this altitude is not as pure as that nearer the earth. The 

 supply is now drawn from the Star Court and the Commons Court. 

 When discharged into the great hall, it has an average temperature 

 of sixty-two degrees F., except in very hot weather, when the 

 velocity of the current is increased to counteract in part the eleva- 

 tion of the temperature. 



SPURIOUS SODA. 



The carbonate of soda sold by druggists under the name of 

 " washing soda," is frequently imitated in England by means of sul- 

 phate of soda, in the following manner: The ordinary " salt cake," 



