456 Comparison of Allumen with Gluten. [JUNE, 
or to gluten. I employed, therefore, common albumen from eggs 
hard boiled, and gluten washed clean from wheat flour, and made 
with them the following comparative experiments :— 
1. Albumen is insoluble in water. ‘The water becomes muddy 
by continued boiling. Albumen dried, especially by artificial heat, 
is much more soluble in water. 
Gluten is likewise insoluble in water. The liquid becomes muddy 
by continued boiling. Dried gluten is much more soluble. 
2. Absolute alcohol does not dissolve albumen. When allowed 
to stand upon it for some time, the liquid becomes muddy. 
Alcehol likewise becomes muddy when boiled with albumen. 
Absolute alcohol does not dissolve gluten. When allowed to 
stand upon it, it becomes muddy. It is rendered muddy, likewise, 
by boiling along with it. | 
3. Very dilute sulphuric acid does not act upon albumen. Boil- 
ing merely separates it into smaller parts. Strong smoking sul- 
phuric acid gradually dissolves the greatest part of the albumen 
without the assistance of heat. The solution is brownish-yellow, 
and muddy. When dropped into water, a white precipitate falls 
similar to fresh albumen. The residual albumen is blackish, but 
transparent. Strong sulphuric acid, when assisted by heat, chars 
albumen. 
- The solution of albumen in sulphuric acid precipitates muriate of 
tin, sulphate of copper, and proto-sulphate of iron, of a brownish- 
white colour. 
Dilute sulphuric acid does not act upon gluten. By boiling, it 
is only more minutely divided. Strong smoking sulphuric acid 
partly dissolves gluten without the assistance of heat. he solution 
has a dark, almost black, brown colour, with a slight tint of blood- 
red. When dropped into water, a yellowish-grey precipitate falls 
in flocks similar to gluten. 
The solution of gluten in sulphuric acid precipitates muriate of 
tin, sulphate of copper, and proto-sulphate of iron, of a dark 
brown colour. 
4. Cold nitric acid gives albumen a yellow colour. By boiling, 
it dissolves it, and the solution is yellow, and quite transparent. 
When a solution of albumen in six times its weight of nitric acid is 
evaporated, oxalic acid is obtained, but in small quantity. 
Cold nitric acid gives gluten a yellow colour. By boiling, a 
yellow-coloured solution is obtained, which remains somewhat 
muddy. The undissolved matter, being separated by the filter, and 
dried, was in flocks, which burnt very easily. By evaporation with 
six times its weight of nitric acid, oxalic acid was obtained in con- 
siderable quantity. 
5. Cold muriatic acid does not act upon albumen. When 
assisted by heat, a solution takes place, which has a blackish brown 
colour. Some flocks remain behind undissolved. - 
Gluten is only dissolved by hot muriatic acid. The solution has 
a brown colour, and some flocks remain undissolved. 
