554 HINTS ON PAPER MATERIALS. 



which, was there valued at 13d. per lb. In the Exhibition six different 

 preparations made in Vienna from Guarana were exhibited in the Aus- 

 trian Court. Guarana has been analysed by Dr. Stenhouse, who ascer- 

 tained that it contained a quantity of a principle first called Guaranine, 

 but which has been found to be identical with Theine, the principle to 

 which both tea and coffee owe their invigorating qualities. The same 

 principle, in the amount of lj per cent., also exists in the Yerba Mat6, 

 the celebrated Paraguay Tea, which consists of the dried leaves of some 

 species of Ilex. 



The powdered seeds of the Paullinia are said to have been employed 

 with much success by French medical men in cases of headache. They 

 furnish by analysis a small quantity of resinous matter, starch, 

 tannin, and a particular alkaloid guaranine. 



HINTS ON PAPER MATERIALS. 



In searching for fibre suited for the manufacture of paper, the fol- 

 lowing hints may be found useful to residents in tropical and other 

 regions. 



Any fibre capable of cohesion when precipitated on a draining sur- 

 face from mechanical suspension in water, after having been reduced to 

 a pure state of capillary subdivision by mechanical action, is fit for the 

 manufacture of paper. 



For all practical purposes it may be accepted as a rule, that for the 

 manufacture of white paper all fibre requires bleaching. 



Raw fibre may be divided into fuur classes : — 



1. That which is easily reduced and easily bleached. 



2. That which is easily reduced, but difficult to bleach. 



3. That which is difficult to reduce, but easily bleached. 



4. That wherein perfect bleaching involves the integrity of the fibre. 

 The most profitable shape in which to send fibre to the English 



market is that of half-stuff (or pulp). Well-prepared bleached half-stuff 

 would fetch 25/. per ton in the market. 



The best maclune for reducing fibre to half-stuff is the ordinary rag- 

 engine, costing about 150/., carrying about 2 cwt. of stuff, and requiring 

 a maximum of 7-horse power for driving. The half-stuff would require 

 to be pressed, dried, and packed in bales. For experimental purposes 

 in reducing the fibre, anything smaller than the ordinary sized rag- 

 engine is useless, as the weight of the triturating roll — about 15 cwt. — 

 cannot be dispensed with, so that laboratory experiments are necessarily 

 confined to rough separation and bleaching. Moreover, laboratory ex- 

 periments, unless conducted with the utmost care and skill, furnish no 



