ON DIGITALIS PURPUREA. 
211 
Now, by the process of the Dublin Pharmacopoeia the color 
is exceedingly impaired. There can be nothing more detri- 
mental to it than the heating for an hour in a bag, at the tem- 
perature of 90° or 100°. I have over and over convinced 
myself, by processes much varied, that to allow the steam of 
the leaves to act upon them for so long a time, or at all, is in- 
jurious to color. I have dried these leaves sometimes in 
paper bags before the fire, or in the sun, or air, sometimes in 
a baker's oven, sometimes stratified on a wire gauze over a 
sandbath, or on a floor in the shade, and have sometimes hung 
them in bundles in a room, in which burned a fire; yet in no 
case did I ever, by these processes, preserve the brilliant green 
in the leaves, which it is their nature to retain under a differ- 
ent management. Yet these are all the methods directed in 
the Pharmacopoeias, and practised by herb dealers, druggists, 
and apothecaries. For proof of the injury done by these 
methods of drying, I refer to the powder of foxglove, pro- 
curable in commerce, the color of which is far inferior to that 
which it is possible to obtain by adopting the process which 
in some future communication I may describe. 
It appears, therefore, that every step, from the collection to 
the drying, occasions deterioration. The softening of the sub- 
stance of the plant when pulled, the expulsion of the volatile 
oil, or other odorous substances during drying, and the change 
of color, owing to bad methods of exsiccation, are the sensible 
evidences of deterioration, and they are strengthened by the 
analogies which have been adduced. If to these injuries we 
add that arising from long delays, generally a week, nay, 
often a fortnight, from the first collection to the final drying, 
there can be little doubt that the plant sustains a great deal of 
injury. 
The following observations of a competent judge, corres- 
pond with the opinions here entertained: " Comme par le 
dessiccation, certaines plantes perdent une partie de leur 
principes les plus volatils, ou subissent des modifications dans 
leur nature intime, il est certain que leur action medicale ne 
doit pas etre la meme qu'avant leur dessiccation. On doit en 
