Proceedings of tee Polytechnic Association. 815 



Dynamite. 

 This name, derived from a Greek word meaning " power," is given 

 to a new explosive compound introduced by Mr. Nobel, the engineer 

 who first brought nitro-glycerine into practical use for blasting. The 

 composition of the new substance was kept secret for some time, it 

 is, however, now known to be simply nitro-glycerine mixed mechani- 

 cally with some inert body. A deposit of infusorial earth near San 

 Francisco, composed of silica and sold as a polishing powder, is the 

 body mixed with nitro-glycerine to make dynamite for California 

 miners, which meets with an extensive sale. 



SUGAK IN BkEWING. 



The quantity of sugar used in the breweries of Great Britain 

 during the year 186Y was 41,134,000 pounds. This is a vast increase 

 over that used in any preceding year, and was doubtless owing to a 

 deficiency in the quantity of malt nj^ade and imported. According 

 to Dr. Ure an equal quantity of proof spirits (eighteen gallons) can 

 be obtained from one quarter of malt weighing 336 pounds ; from 

 1T5 pounds of the best West India sugar ; from 234 pounds of 

 . inferior Jamaica sugar, and from 295 pounds of refined or sugar- 

 house molasses. The manner of using sugar in brewing varies 

 considerably in diiferent breweries. A common practice is to 

 dissolve it in boiling water and add to it the malt worts in the hop 

 back. Some brewers place the sugar in the coolers ; others in the 

 fermenting tuns shortly before cleansing, and if it is thoroughly 

 dissolved before being casked, quite enough fermentation will have 

 ensued. When sugar is used in very small quantities it is sometimes 

 put into the casks of beer after fermentation has ceased, but 

 great care must be taken to put it in at the right time ; and it must 

 not be done if the beer is to be kept for any length of time, for the 

 second fermentation thus set up is sure to be followed by a reaction 

 of fiatness, with great tendency to acetous fermentation. The 

 quantity of malt imported into Great Britain in 1867 was less than 

 that imported in 1866 by more than 2,750,000 hundred weight. 

 Brewers, having discovered that they can make an acceptable bever- 

 age by substituting sugar or molasses for barley and adding 

 pernicious narcotic adulterations, will probably never return to the 

 old fashioned method of brewing, and British beer must hereafter be 

 defined as a mixture of rum and malt liquor. 



