The Life and Labours of John Mercer; Including Numerous Recipes Used at the Oakenshaw Calico Print-Works (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1886 edition. Excerpt: ...so important to a calico-printer, ' he made numerous experiments with the view of ascertaining the variations presented by solutions of the same substance of different strengths. The question of the practicability of effecting a partial separation of different hydrates by slow fractional nitration then occurred to him, and led him, among other experiments, to try the effect of filtering solution of caustic soda through cotton. ' For this purpose, ' he wrote, ' I made a filter, composed of six folds of strong, fine cotton cambric, bleached, passed three times through 1 In a paper read before the Royal Society in June, 1861, ' On the Capillary Transpiration of Liquids in Relation to their Chemical Composition;' published in the Phil. Trans. 1861. the calender to make it compact, and poured upon it solution of caustic soda of 60 Tw. The filtration was very slow; the liquor which passed through was of 53 Tw. (as well as I remember). But I found my filtering-cloth had undergone an extraordinary change; it had become semi-transparent, contracted both in length and breadth, and thickened or " fulled," as I then termed it. I then spotted bleached cambric with single drops of caustic soda of 60 Tw. and 50 Tw., and noticed that the central portion of each drop (about the size of a shilling) became semi-transparent and contracted; around this was a rim of a quarter of an inch, neither semi-transparent nor contracted, which evidently contained but little soda. I then spotted cloth with drops of soda solution which had been previously coloured with various colouring matters, and found that in all cases the colouring matter was transmitted to the outer portion, very little remaining in the central or contracted part. On mixing stannate of soda with the soda...