( 31 )
The results in these tables indicate a good deal of irregularity, but they
point very clearly to several important facts. The loss of moisture when the
gánjá was dried by heating was in all except one instance greater than the loss
when dessicated in a dry atmosphere at ordinary temperatures. The exceptional
sample, it may be remarked, was derived from gánját h a t c o u l d n o t b e o b t a i n e d i n
Calcutta, and had therefore to be obtained from Naogaon, where it had been stored
under far less favourable conditions for keeping. As regards the samples of
new gá nj á , i t w i l l b e n o t i c e d t h a t w h i l e t h e y d i d n o t i n t h e d r y a t m o s p h e r e l o s e
perceptibly more than did older samples when dried by heat, they lost markedly
more weight than the others. This points to some of the volatile constituents of
the drug having been driven off along with the moisture, and suggests the
possibility of an alteration of the quality of the drug resulting from the heating.
The absorption table confirms this suspicion, for it will be noticed that while the
samples dried at ordinary temperatures re-absorbed in most cases rather more
than the sum of what they had lost, and of what powdered drug not dried at all
will take up in a saturated atmosphere, two-thirds of the samples that had
been dried in the air-bath did not regain all that they had lost, while the
remaining three regained the amount, but no more. Exposure to heat must
therefore produce some permanent and deleterious change in gánjá.
The effects of humidity are hardly less deleterious. The samples, after
estimations of their weight had showed that this ceased to increase and that no
more moisture could be absorbed, were left exposed either in the air or under
a bell-jar ; in every case by the third day in a saturated, by the fifth day in an
ordinary, atmosphere they became covered with a crop of mould.
The irregularity of the results of these physical estimations show the
inadequacy of conclusions based on the examination in any one year of samples
from crops of different seasons of growth. To overcome this defect, arrange-
ments have been made which will render possible the examination of sam-
ples of the same season and from the same field at different ages. From
Naogaon were brought four samples of each of round and flat gánjás. These
have been duly labelled and are now stored in the Government golahs at Calcutta.
They are intended to be issued as follows :—One sample of each of round and
flat to be examined towards the latter part of 1893, after the cessation of the
rainy season; a second sample of each to be examined during the hot season of
1894, when the samples are a year old ; a third sample of each in 1895, when
the samples are two years old the fourth sample in 1896, when they are three
years old. In this way, and in this way only, may reliable results be hoped to
be obtained. A corresponding number of samples have been hermetically sealed
in tin-cases and marked and stored like the samples not placed in tins. On each
occasion on which an untinned sample is examined the corresponding tinned
sample should be examined for comparison.
CHAPTER XIII.—THE CHEMICAL CHANGES THAT OCCUR IN GÁNJÁ.
In order to ascertain the chemical changes that accompany the physical
alterations described in the preceding chapter, a chemical examination was
made of the various samples of gánját h e r e r e f e r r e d t o .
In order, if possible, to compare the results with those obtained by Dr.
Macnamara ¹a n d D r . O ' S h a u g h n e s s y ,
2 a n e s t i m a t i o n o f t h e i r t o t a l a l c o h o l i c
extracts was made. Macnamara only obtained between 4 % and 6 % of extract
from Bengal gánjá,w h i l e O ' S h a u g h n e s s y h a d s t a t e d t h a tg
á n j á
y i e l d s
2 0 %
o f
extract. Unfortunately neither Dr. O' Shaughnessy nor Dr. Macnamara describe
the treatment to which the samples operated on by them were subjected before
their digestion in alcohol.
In the present instance gánjá of the various samples was first reduced to
chúr ; this chúr was reduced to a coarse powder, from which the woody portion
was mainly removed by sifting ; this powder was then sifted through a wire
sieve of 36 to the inch mesh. From each sample ten grammes of the powder thus
obtained was then, without having been previously freed from moisture, placed
¹ Letters from Chemical Examiner to Board. of Revenue, Lower Provinces, March and April 1872.
² Bengal Dispensatory, p. 581.