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printers of these fabrics will admit, a step of very great 
importance, and had Mr. Mercer patented this invention a 
very large sum would probably have accrued to him. It 
was, however, given to the trade with no reservation what- 
ever. To Mr. Mercer must be attributed the discovery of 
the peculiar action of caustic soda and sulphuric acid upon 
cotton. This singular process, now called “mercerizing” 
has the effect of untwisting the normally twisted flattened 
tubes of cotton filaments and converting them into cylin- 
drical tubes. When colours are applied to the cotton so 
treated they pass more readily through the minute pores of 
the tubes and are precipitated in denser layers in the interior 
of the latter, whereby darker and more permanent shades 
are produced. Calico so treated has become greatly increased 
in strength, and though hitherto no large quantities of cloth 
thus prepared have been printed, owing to the expense of 
preparation, advantage has been taken of the process to 
prepare the cotton fabric used in the production af the end- 
less web known to calico printers as the indiarubber blanket, 
which, when made with prepared calico, is rendered much 
more durable, 
Mr. Mercer acted as a chemical juror for the Great Ex- 
hibition of 1851, as well as that of 1862. In 1852 he was 
elected a Fellow of the Royal Society. He was an honorary 
member of this Society as well as of the Glasgow Philo- 
sophical Society. He was put on the commission of the 
peace in 1861. Mr. Mercer closed a long period of useful 
labour on November 30th, 1866, after several years of 
suffering, borne by him with great fortitude and resignation. 
He had endeared himself to all who knew him by his sim- 
plicity of character, large-hearted kindness, and purity of 
life. To the poor his hand was always freely extended, and 
having himself been one of the people, he knew how to 
sympathise with their sorrows and give aid where most 
wanted. Though dying at an advanced age, his loss is f§lt 
