Experimental and Applied 291 



qualitative reactions (dyeing phenomena &c.) available for 

 demonstrating the formation of oxidation products. As it is 

 probable that condensation to furfural is a property of these 

 oxycelluloses, and the estimation of this product is reduced to 

 a method of precision, it would be important to investigate 

 the cotton in three stages, viz. : (i) in the raw state ; (2) after 

 alkaline treatments of varying degrees ; and (3) after bleaching 

 processes of various kinds and degrees, for the presence of 

 furfural-yielding constituents and their quantity. 



The classification of cotton-cloth bleaches into * market 

 bleach,' * madder bleach,' &c., involves no important question 

 of principle ; and for description in detail of the variations of 

 treatment practised in the several grades, the technological text- 

 books must be consulted. We would specially mention, in pass- 

 ing, the article on ' Bleaching,' in Watts' Dictionary (Applied 

 Chemistry, new edition), which gives an excellent survey of the 

 history of development of the art. It may very well be assumed 

 by those familar with this history that we have arrived at terminal 

 excellence in the art. From the economical point of view it 

 is, perhaps, difficult to see any unexplored margin. But, on the 

 other hand, there is evidence of important recent progress in a 

 direction of improvement, which will be evident from the 

 following considerations. A web or fabric of cotton must be 

 always considered by the technologist from the point of view 

 of minute structure, the structure being that of the ultimate 

 fibre, complicated by the spinning twist and the interlocking of 

 the yarns in the weaving. The penetration of cotton goods in 

 the mass by liquid reagents is obviously a highly complicated 

 process. In the first place, complete penetration is probably 

 possible only by previous exhaustion of the air contained in 

 the tubes ; and, secondly, penetration of the substance of the 

 cell wall must involve osmotic phenomena. Osmosis is compli- 

 cated in two directions : first, by the filtering-out of the active 



