162 



on the defects and want of strength 

 Quantities and Prices of Finished Products. 







Price 





Value. 





Tons. 



£ 



s. 



d. 



£ 



Alkali . 



43,500 



8 10 







369,750 



Crystals of Soda . 



51,300 



4 15 







243,675 



Bicarbonate of Soda . 



7,450 



12 











89,400 



Caustic Soda 



580 



18 











10,440 



Hyposulphite of Soda . 



400 



25 











10,000 



Oil of Vitriol 



6,440 



6 











38,640 



Epsom Salts 



1,500 



7 



5 







10,875 



Bleaching Powder 



11,200 



9 











100,800 



Soap .... 



. 6,000 



34 











204,000 



Yellow Prussiate of Potash 



105 







1 



#1611,760 



Red ditto . 



40 







2 



6 #1511,200 



Alum 



4.000 



7 











28,000 



Carbonate of Magnesia 



250 



30 











7,500 



Superphosphate of Lime 



15,000 



5 











75,000 



Pearl Hardener . 



2,000 



10 











20,000 



Sulphate of Iron 



2,000 



3 











6,000 



Venetian Red 



4,000 



5 











20,000 



Sulphate of Copper 



100 



35 











3,500 



Resin Size . 



100 



7 











700 



Lamp Black 



1,200 



7 











8,400 



Grease 



. 2,800 



8 











22,400 



Cements 



12,000 



2 











24.000 



ON THE DEFECTS AND WANT OF STRENGTH OF CERTAIN 

 MODERN PAPERS. 



BY DR. VAN DEN CORPUT. 



Although, the papers which are now made are infinitely finer, more 

 beautiful, and above all whiter than those made in former times, it is 

 equally true that, generally, machine-made papers possess less strength 

 than the old hand-made papers. But if it is probable that the rapidity 

 of the mechanical operations, to which paper is subjected under the 

 modern system, and especially the accelerated desiccation which it 

 undergoes, causes it to lose a part of its strength, it is still more certain 

 that other more powerful causes have contributed, in the last few years, 

 to the want of solidity in this article. These causes are principally— 1st, 

 the mixture, of cotton and of an infinity of other materials of inferior 

 quality with the stuff. 2nd, the too-prolonged immersion in ley of the 

 straw-like substances. 3rd, the destructive effects of an excess of 

 chlorine which ordinary rags require. 4th, the insufficient washing of 

 the pulp, and consequently traces of free chlorine, which the paper 



