Mechanical Science. M© 



ment will accomplish a saving in the cost of the iron in Great 

 Britain to the amount of at least 200,000/. per year. — Jameson** 

 Journal^ Jan. 1830. 



10. Preservation of Corn in Siloes. — An account has been read 

 to the Society of Agriculture in France, of the opening of a silo, 

 in which the corn was found in an unexpected state. The 

 place consisted of an ice-house, and the grain, when put in, was 

 of the finest appearance, perfectly dried, and in excellent con- 

 dition. The door had been hermetically sealed, and yet, when 

 opened, a considerable thickness of the mass of corn was found 

 destroyed by weevils, the latter being in such quantity as to 

 occasion an elevated temperature. As part of the same corn had 

 been perfectly well preserved in other siloes, the cause of this 

 deterioration was sought for, and a hole was found in the lower 

 part, which had been made by mice, and which, by admitting air 

 in sufficient quantity, had allowed the weevils originally in the 

 corn to live and increase their numbers to the degree mentioned. 

 After some observation upon experiments, which shewed that 

 insects could live for a very long time in vitiated air, a committee 

 was named to ascertain the requisite state of the air, and the 

 circumstances connected in the inquiry, with the preservation of 

 grain in these repositories. 



At another meeting of the society, M. Hachette described the 

 method proposed by M. Clement to prevent the destruction of 

 corn by weevils. It is founded upon a fact observed by him, 

 that these insects cannot live in an atmosphere which contains 

 less than a certain proportion of moisture. He therefore pro- 

 poses that the corn shall be subject to a continued ventilation of 

 air, dried by passing over quick lime or chloride of calcium. 

 All the weevils originally in the corn would thus be quickly 

 destroyed. — Recueil Industriel, xii. 73. 208. 



§ IT. Chemical Science. 



1. Preparation of Bromine and its Hydrate. — The mother 

 liquors containing bromine are to be evaporated to a fourth of 

 their volume in iron pans, and then left for several days, in which 

 time the largest part of the chloride of calcium crystallizes. The 

 supernatant liquor, being diluted with water, is to be mixed with 

 sulphuric acid as long as a precipitate is formed. The liquid 

 portion being separated, and the solid residue pressed, all the fluid 

 is to be mingled and evaporated to dryness, and then re-dissolved, 

 that a certain quantity of sulphate of lime may be removed. On 

 acting upon the solution by sulphuric acid and peroxide of manga- 

 nese and then distilling, bromine is obtained. 



Hydrate of Bromine. — ^This compound is easily formed at a tem- 

 perature of 'from 4° to 6° (39° to 43° F.), by making the vapour 

 of bromine pass into a tube moistened with water ; in about a 



