64 Recipe for an elastic and permanent Varnish , 
Preparation of Linseed Oil , under the Denomination of 
Oil of Marmite. 
Take Linseed oil . 15 pounds. 
Umber . 4 ounces. 
Red lead . 1 pound 8 ounces. 
White lead . 2 pounds 4 ounces. 
Put the whole in a pot placed upon a coal fire ; boil it for 
thirty- six or forty minutes ; stir it from time to time with 
a wooden spatula ; and care must be taken that it is nei- * 
ther too little boiled, nor viscous from being too much. 
Upon taking the pot off the fire, throw in a piece of 
bread, both crust and crumb, of the size of a small loaf. 
Cover it, and let it cool for twenty-four hours. The oil 
thus prepared is made use of for various purposes. 
Composition of the Blade Varnish . 
1 . Take of black umber two pounds thirteen ounces ; 
cut it into small pieces, and place them in a frying pan 
upon a very brisk fire, and roast it like coffee for about 
three quarters of an hour; bruise it afterwards upon a 
marble slab, by mixing it in the manner of painters, with 
a little boiled linseed oil, and keep it in a stone pot. 
2. Take three pounds of verdigrise ; reduce it to an im- 
palpable powder ; mix it with the boiled linseed oil ; then 
put it into the stone pot which contains the umber. 
3. Take of lamp-black one pound, mix it also with boil- 
ed linseed oil, and after putting it also into the stone pot, 
blend the whole well together. 
This is the mixture made use of to varnish articles of 
felt, cloth, or leather, observing that when leather is to 
be varnished it is essential to give it previously two or 
three, and sometimes even six coats of linseed oil ; it must 
be well dried each time, in order to extract the grease 
