37® Mr. W. Brande’s Observations on Albumen , 
only a thin film of albumen collected at the positive wire, 
where its appearance was readily accounted for, by the sepa- 
ration of a little acid, which re-acting on the albumen would 
render it solid ; but the cause of the abundant coagulation at 
the negative pole was not so obvious. 
This result I mentioned to Mr. Davy, who immediately 
offered an explanation of it, by supposing the fluidity of albu- 
men to depend upon the presence of alkaline matter, the se- 
paration of which, at the negative pole, would cause it to 
assume a solid form. I had only to follow up this idea, and 
shall proceed to state the principal experiments which were 
undertaken to establish so probable an opinion.* 
i. When coagulated albumen, cut into small pieces, is boiled 
in distilled water, it imparts a viscidity to that fluid, shewing 
that something is retained in solution. 
Two hundred grains of the coagulated albumen of an egg,, 
were repeatedly washed and triturated, in four ounces of dis- 
tilled water, which, was afterwards separated by a filter, and 
evaporated to about one fourth of its original bulk. It was 
then examined by the usual tests, and was found evidently 
alkaline ; it converted the yellow of turmeric to a pale brown, 
and restored the blue colour to litmus paper, reddened by 
vinegar ; but it did not appear to effervesce on the addition of 
a dilute acid. 
On evaporating this alkaline fluid to dryness, by a gentle 
heat, a viscid substance, soluble in water, was obtained. This 
solution was rendered slightly turbid by an acid ; and by the 
* On referring afterwards to Dr. Thomson’s System of Chemistry (Vol. V. page 
491), I Snd that a very similar explanation of the coagulation of albumen has been 
offered by that author, which the following experiments will likewise confirm. 
