ON MADDER. 125 ' 75<?£ 
very pure, and quite free from its epidermis or any foreign 
earthy matter, and dried with care, gives by incineration 5 
per cent, of ash ; that the Lizaris of Provence, stripped of 
its pellicle, gives on an average S.80 per cent. ash. 
According to M. Henri Schlumberger, 100 parts of Alsa- 
tian Lizaris, washed in distilled water, and dried at 212°, 
give 7.20 per cent, of ash; whilst 100 parts of Lizaris of 
Avignon, prepared in the same way, give S.766. 
According to M. Chevreul, 100 parts of Lizaris from the 
Levant, dried at 212°, give 9.S0 ash. 
When an Avignon madder, SFF, (the mark most gene- 
rally used,) subjected to the test of incineration, gives a 
greater weight of ash than 5 per cent., which I have taken 
as the mean of numerous experiments, the excess must be 
attributed to the presence of foreign earthy or sandy matters, 
either arising from adulteration or a careless preparation of 
the powder. 
When the excess is only from three to four-hundredths, 
it is probably owing to some fault in the preparation of the 
madder, the manufacturer not having separated the epider- 
mis (which is always coated with the earth which surrounds 
the roots) carefully enough by grinding ; but when the ex- 
cess is above 4 or 5 per cent, or more, it is the result of 
fraud. 
The madders obtained from the merchants give very va- 
riable results with respect to the proportions of ash which 
they furnish, as the following table shows: — 
Per cent, of Ash. 
On 6 trials the mulle madder of Avignon 
gave 4.00 
On 7 trials the madder SF of Avignon gave 
from 12.40 to 20.00 
On 18 trials the madder SFF of Avignon 
gave from 7.40 to 23.00 
On 4 trials the madder SFFRP of Avignon 
gave from 12.00 to 16.00 
