254? Method of giving to Cotton and Linen Thread 
threads, in any manner whatever, more or less alumine, 
after having applied to them a slight stratum of oil. The 
complete success of the result, however, depends on cer- 
tain modifications to be observed in the processes. 
The numerous trials which I made in dyeing had so 
much familiarised me with experiments on a small scale, 
that I at last never failed. It was only after I published 
my memoir on maddering inserted in the Jlnnales de Chi - 
mie *, that I experienced any difficulties in the applica- 
tion of oil when operating on a larger scale. Linseed oil, 
which had always given me a milky mixture in limited 
proportions with alkaline solution, then speedily separa- 
ted when I wished to make a larger provision, and under 
these circumstances the impregnation of the skains be- 
came impossible. The case was the same with all the fat 
oils : fish oil, however, will remain in mixture for a con- 
siderable time ; but its odour is too disagreeable. 
To remedy the inconvenience of the separation of oil 
in the alkaline solution of alumine, I had recourse to dry- 
ing oils ; that is to say, oil boiled with metallic oxides. 
Linseed oil boiled with minium, ceruse, or litharge, by 
means of water to prevent combustion, dissolves a consi- 
derable portion of the oxide of lead, and will keep mixed 
with the alkaline solution of alumine, under the milky 
form, the whole time necessary for the impregnation of 
the skains. By employing this mixture in proper propor- 
tions, and in the manner I have indicated in my memoir, 
following strictly in other respects the process such as I 
have described it, one cannot fail to obtain beautiful and 
lasting colours. However, notwithstanding the simplicity 
of this process, I cannot recommend the use of it, because 
it exposed me to the danger of a conflagration in the fol- 
lowing manner : 
* See Emporium, preceding- numbers. 
