ON THE PAPER MANUFACTURE. 393 



paper, and of fibrous material suitable for some branches of the paper 

 manufacture, are so multifarious as to defy enumeration. Plastic art 

 annually demands a considerable quantity ; and, as a curiosity in its 

 way, we read that in Bergen there is an elegant church, capable of hold- 

 ing 1,000 persons, constructed entirely, statues and all, of papier mache. 



The transformation of water-leaf, or unsized paper, into a material 

 in exact resemblance to parchment, is one of the chemical facts of the 

 last few years. This metamorphosis is effected by dipping the paper in 

 a vat of dilute sulphuric acid, which must be of an exact stated strength, 

 as either an excess or paucity of acid in the vat fails to effect the desired 

 result. Dr. Hofmann reports that the product resembles in every respect 

 animal membrane — " The same peculiar tint, the same degree of trans- 

 lucency" and horndike condition. "Immersed in water, vegetable 

 parchment exhibits all the character of animal membrane, becoming 

 soft and slippery by the action of water, without, however, in any way 

 losing its strength. Water does not percolate through vegetable parch- 

 ment, although it slowly traverses the substance like animal membrane 

 by endosmotic action." A set of experiments, conducted by Dr. Hof- 

 mann, to test the relative strength of vegetable and animal parchment, 

 resulted as follows : — 



Water-leaf paper broke when loaded with 



i. ii. in. Mean. 



171b. 151b. 151b. 15-6lb. 



Vegetable parchment broke when loaded with 



I. ii. in. Mean. 



781b. 751b. 701b. 741b. 



Animal parchment broke when loaded with 



1. ii. in. Mean. 



921b. 781b. 561b. 75lb. 



And the operator continues to say " The strips of vegetable and animal 

 parchment were selected as nearly as possible of equal thickness, but 

 the strips of the artificial product were somewhat heavier than those of 

 real parchment. On an average the former weighed 18 grains, and the 

 latter only 12.75 grains. Calculated for equal weights the strength of 

 animal parchment as compared with that of artificial parchment is 

 obviously ^Vs- x 75 = 105, in round numbers, it may be said that 

 vegetable parchment has three-fourths the strength of animal parch- 

 ment." Under the name of artificial parchment, Captain J. H. Brown, 

 R.N., started a process at Romsey, for making parchment direct by 

 treating the parings of raw hides with alkaline solutions, and succeeded 

 in producing a very capital substitute for parchment. Satisfying all the 

 conditions, even to appearance, specifically belonging to the original 

 article ; but on refusing to take out a papermaker's licence, on the plea, 

 as he informed us, that with a paper label attached, the article could not 

 be sold as parchment, realising its proper value, the Excise instituted 



