1 "24 Processes for preparing Lake Jrom Madder* 



trituration, bags of woollen, such as are used in the oil-mills, 

 would probably answer as well as calico, and they would 

 be much cheaper and more durable. A large vat, with 

 stampers, would be easilv constructed, by those who are 

 conversant in mechanics, for the holding them and pressing 

 them in water; and when the colour was boiled and jireci- 

 pitated, the flues of the l)oilcrs might easily be formed into 

 convenient drying-tables, without any additional expense of 

 fuel. The part of the process which 1 consider as of the 

 greatest importance, and as being the essential advantage of 

 my methods over all those which have come to my know- 

 ledge, is the trituration or pressing of the root in water ; 

 and I believe that the colouring matter of the root has not 

 been hitherto considered as so nearly insoluble in water as 

 I have reason to think it is. 



It were much to be wished that in the present advanced 

 state of chenjistrv some skilful analyser would investigate 

 the properties of this very useful root, in which perhaps it 

 will be found that there are three, if not four, difierent co- 

 louring substances. Such are the processes and views, 

 which I have thought it not improper to submit to the con- 

 sideration of the Society of Arts, &c. 



I have only now to describe the specimens which accom- 

 pany this paper; assuring the societv that th(;y have been 

 all prepared bv nu' own hands entirely, and that I am 

 therefore responsible for their having been produced by the 

 processes stated, without the addition of any foreign matter 

 whatever, excepting the cake grovmd up with gum, and 

 the bladder of oil-colour, which were prepared from the 

 colour which I gave him, bv Mr. Newman, of Soho-square, 

 whose skill and lidclitv are too well known to need any tes- 

 timony in their favour. 



It may be proper to add, that all the colours produced 

 from the Dutch madder were prepared from the same parcel 

 of crop madder, in order that the diflercnccs in them might 

 proceed from the processes, and not from a variation in the 

 qualities of the root, which, in diB'erent specimens, will 

 produce different shades of colour under the same mode of 

 treatment. 



1. Dutch madder, treated by Process 1st. 



3. Ditto ; Process 2d. 



3. Ditto Process 3d. 



4. Ditto Process 4th. 



5. Dutch madder, two ounces ; alum, half an ounce ; 



treated by Process 2. 



6. Dutch 



