%iO Observations on Maddening ? 
the water employed does not contain some of it. Four 
parts of this colouring substance will produce a red too 
intense and beautiful to he employed in commerce, as it 
would be too dear to find purchasers. 
By making an oily alkaline solution of alumine with 
two or three parts of water, and impregnating the ska ins 
twice, and even four times, in the manner above mention- 
ed, bright shades will be produced without the use of 
much madder ; but they will not have the same intensi- 
ty as those procured with even as little madder by means 
of the same solution concentrated. 
The best method of obtaining shades lively as well as 
bright, is to expose the dark reds for a considerable time, 
when they have been cleared, to the action of a ley of 
oxygenated muriate of potash, or of soda with excess of 
alkaline carbonate, in order to have such a degree of 
shade as may be required : but it may readily be con- 
ceived that this method would be expensive. 
To have the oily alkaline solution of alum nearly in 
the same state of concentration, it will be necessary to 
employ an areometer to determine the degree of strength 
of the caustic ley before it is employed for the solution 
of the alumine. This caustic ley must be made with the 
best common potash that can be procured, and the de- 
gree it gives by the areometer must be noted, in order 
that, if potash of an inferior quality be afterwards em- 
ployed, the ley obtained may be carried to the fixed de- 
gree by evaporation. 
Caustic ley made with four parts of good common pot- 
ash* cannot contain a large quantity of foreign salts. 
By making it on a large scale, when the limpid part has 
been decanted, it will be necessary to shake the deposit, 
for some time, twice every day, that the rest of the alka- 
* I have no doubt that, where potash cannpt be procured, soda might 
employed. The Author, 
