15 * 
formation into white indigo, takes about two hours under the 
influence of a special ferment. u Diastase, ” hydrating and oxyda- 
ting, which exists in the cells of the leaves. The liquid is then 
withdrawn from the warm maceration, and is cooled with cold air 
by some mechanical means. The white indigo becomes blue indigo 
but insoluble. By these means three times more indigo is produced 
than by the primitive method. The indigo thus obtained is very 
pure, and contains from 80 to 82 per cent, of indigotine, the colour- 
ing matter of indigo. 
INSTRUCTIONS FOR DRYING PLANTS, 
By C. Curtis, f. l. s. 
Many readers of this Bulletin will occasionally come across a plant 
of which they would like to know the name, and it is not so gener- 
ally understood as it should be that in most cases plants can be as 
easily determined from dried as living specimens. There is a story 
told in botanical circles, of a living plant being brought to an emi- 
nent botanist which he failed to identify, but he hinted that if it 
were taken away and sat upon for a week he would probably be 
able to name it. In the case of timber trees, and other large 
growing plants, it is manifestly impossible to send specimens for 
.dentification, any great distance, in any other way except dried, 
and as there is still much to be done in collecting and determining 
the Forest Flora of this region it is with the hope that some at 
least of those who are living amid forests will turn their attention 
to collecting and drying plants, that I propose giving a few hints 
as to how to do it. A complete specimen consists of leaves, 
flowers and fruits, and in the case of small growing plants it is 
desirable to have the whole plant with the roots attached. Such 
specimens are not always obtainable at the same season and in 
that case leaves and flowers or leaves and fruits will suffice, but 
leaf specimens alone are seldom sufficient for determination. 
Whenever possible the specimens should be gathered dry, and if 
wet should be laid out singly for an hour or two before putting them 
in paper to allow the moisture to evaporate, but not long enough to 
allow them to wilt. In the case of fleshy plants or those that dry 
badly; thatis to say, those from which the leaves drop off even with 
the greatest $are, immersion for a few minutes in spirits of wine or 
boiling water is a good plan. After immersion these should also 
be laid out singly until the moisture has evaporated. 
All sorts of more or less elaborate presses have been devised for 
drying plants, but there is nothing better than a pair of simple wood- 
en frames as shown in the accompanying illustration, and which I 
have used for more than twenty years. Each frame consists of 
eight pieces of any strong light wood, three-eighths of an inch thick, 
and two inches wide. Five of these, twenty-three inches long, are 
placed about two inches apart and to them nailed transversely three 
pieces twenty inches long. The drying paper, which should be of 
an absorbent kind, (there is nothing better than blotting paper 
