202 PROCEEDINGS OF THE CANADIAN INSTITUTE. 



making by hand ; still continued, but mostly due to the conservatism 

 of the people, though good for Bank Notes. He described the pro- 

 duction of water marks and showed some beautiful specimens. He 

 explained the disinfecting of rags by a machine which takes in a 

 bale, bores it throughout and disseminates sulphurous acid to a 

 sufficient extent. The rag trade and its tricky dealers. The 

 mill operations in cleaning, sorting, cutting, boiling and bleaching. 

 Before the discovery of chlorine for its powerful bleaching, the 

 color of the rags determined the color of the paper. Rags to be 

 kept dry and in moderate heaps, for fear of spontaneous combustion. 

 Wood is received at the mill as cordwood, is freed from bark and 

 dead-knots and piled up to dry. It is then fed on to a machine which 

 grinds it to dust ; or better, which cuts it into small chips ; the best 

 is to cut it into blocks, as the fibres are but little broken. The wood 

 is then boiled at a high temperature and with strong chemical agents 

 to soften the wood, toughen the fibres and lessen their adhesion, 

 after which they are soon ground to pulp. The object of boiling all 

 papermaking substances is, to decompose the fatty, glutinous and 

 coloring substances and remove everything but pure fibre. 



The alkaline substances used are fresh burned quick-lime or 

 the milk of lime, carbonate of soda and caustic soda. 



The boiling is continued for about twelve hours, but ropes and 

 bagging require twice that time. 



The materials must then be washed from all impurity, most surely 

 from all traces of chlorine. 



They are next put into the Beating-engine and macerated into 

 fibre by knives and friction. Everything to be added to the fibre 

 must be put in here, such as china-clay, sizing or coloring. 



Animal sizing is obtained fx'om skins, ligaments, cartilages, tendons, 

 hoofs and ears of animals, steamed and sti-ained until only 5% of 

 matter is left ; alum is added to prevent fermentation or decomposi- 

 tion of the gelatine. Paper run through this is known as tubsized 

 paper. 



Vegetable sizing is composed of resin, carbonate of soda and alum, 

 this mixture is added to the pulp in the Beating-engine and such 

 paper is known as engine-sized. 



There are two degrees, viz. soft-sized and hard-sized and are mostly 

 applied to printing and book papers. 



