cupwiest News, Determination of the Amount of Morphia in Opium. 47 
hat the excess of indigo commences with the brown: ON THE 
stage. If the brown Shien is gonad jute Sevgral times DETERMINATION OF THE AMOUNT OF 
ts volume of water, the colour immediately changes to UM. 
green. This treatment with water is a very convenient MORPHIA PRESENT IN OFI 
method of ascertaining the final reaction. . By E. F. TESCHEMACHER, F.C.S., &c, 
When 2 volumes of oil of vitriol are employed, the tint 
jue to excess of nitrate is less deep and red than with 
{ volume of acid, and approaches a dark sherry colour; 
with more indigo this passes through the brown and green 
stage. The brown, green, and superior tints, when poured 
into water, yield green for an instant only, the colour 
quickly passing into cinnamon. The cinnamon solution thus 
Jbtained is capable of decolourising a rather considerable 
quantity of indigo. It will be recollected that with 
2 volumes of oil of vitriol far less indigo is oxidised than 
when a smaller proportion of sulphuric acid is used: it 
would appear that with 2 volumes of acid some lower 
oxide of nitrogen remains in solution, and on the addition 
of water becomes capable of destroying indigo. 
With an intermediate proportion of oil of vitriol 
{1} volumes) the tints are similar to those with 2 volumes, 
ut more feeble in intensity ; the brown tint and the tints 
superior to it change to green on dilution. 
With_very weak solutions of nitre the tints obtained 
with 1 volume of oil of vitriol are similar to those yielded 
by stronger solutions ; the brown is changed into a dis- 
Hin green on filling up the flask with water. With 14 vol- 
ame of acid the final tints are feeble and unsatisfattory. 
With 2 volumes of acid the tints produced are much 
jeeper than with 14 volume; the indigo and blue are 
specially intensified. 
The best plan seems to be to adopt the brown tint 
whenever possible as the point of final rea&tion, or, more 
sxadly, that particular brown tint which yields a distinét 
yellowish green on dilution. In all exact work a check 
experiment should be made with rather less indigo than 
‘hat yielding this green tint, to make sure that no smaller 
amount of indigo will produce a similar reaction. Work- 
ing with z volumes of oil of vitriol, the green tint produced 
by dilution must generally be dispensed with ; but if the 
sye has been educated to the particular shade of brown 
which yielded green in the former cases, it will be able to 
liscriminate this tint with fair accuracy without dilution. 
In the case of weak solutions the eye can be helped by 
ransferring the contents of the flask to a cylinder, 
In the case of experiments with 1 volume of oil of 
vitriol, the tint, whether in strong or weak solutions, soon 
-eaches a definite point, beyond which no further change 
occurs. But with 13 or 2 volumes of acid the tint conti- 
ues to change slowly (especially in dilute solutions) after 
-he first main rea&ion is over; if, therefore, definite re- 
sults are wanted, it is quite necessary to time the experi- 
ment, and to take that as the final tint which is observed 
at a fixed interval after pouring in the oil of vitriol. I 
aave taken two minutes as the period to elapse before the 
;int is recorded, but, except in the case of weak solutions, 
one minute would suffice. 
The determination of the final rea®ion is undoubtedly 
sne of the weak points of the method, but with care and 
sractice the difference between similar experiments need 
scarcely exceed 1 per cent in the case of moderately 
strong solutions (1'0 to o'5 grm. of nitre per litre), and 
with weak solutions (0°25 to o'10 grm. per litre) should not 
be greater than 2 or 3 per cent, supposing that in each 
case an indigo of appropriate strength is employed. 
A few experiments have been made with an indigo so- 
lution prepared by dissolving sublimed indigotine in 
sulphuric acid. With this solution the colour produced 
oy an excess of nitrate is much less deep than with a 
solution of ¢ indigo-carmine ;” the tint is golden and not 
red, and passes into bright green without an intermediate 
orown stage. The colour reaction with this indigo solution 
is very sharp. 
[N placing in the hands of Chemists one more process for 
letermining the amount of Morphia present in Opium, it 
must not be assumed that the labours of my predecessors 
n this field have been ignored or disregarded by me. 
Most gladly would I have adopted any one of these numer- 
Jus processes had it, on trial, afforded similar, definite 
and reliable results in the amount and purity of the mor- 
shia obtained. That these processes fail to yield satis- 
factory results when they are based on sound methods of 
srocedure, is, to my mind, due, partly to the authors 
raving failed to describe and insist on the necessity of 
‘ollowing each and every step, however minute, of their 
srocess; and, partly, to their having, too readily, jumped 
to the conclusion of the excellence and certainty of their 
methods, without painstaking and long-continued investi- 
jation of the subje, and repeated reviewal and testing of 
avery discernible or probable source of error. 
On the first of these grounds, I claim the indulgence of 
Il who may take an interest in the subject, for the many 
ninute directions and explanations I shall feel it to be re- 
juisite to place before them ; and as to the second I would 
\ssure them that the process described is but the outcome 
and result of very numerous experiments, the details and 
sonditions of which have been changed and modified, as 
requent practice for some years past proved to be advisable 
or necessary ; so that the method as now worked out and 
described, but slightly resembles the process in its in- 
teption. 
Amongst the conditions requisite to success in deter- 
nining the amount of Morphia present in Opium, are :— 
1. The avoidance of the use of Alcohol to extract the 
Morphia from the Opium. This rule leads at once to the 
rejection of very many facile and seemingly excellent 
methods ; and the reason for its adoption is, that Alcohol 
jissolves the whole of the Narcotin as well as the Morphia 
sresent in Opium, and that, in practice, it is very difficult 
f not impossible to separate the whole of the Narcotin 
ander such conditions from the morphia; soit is essential 
that the greater part of the Narcotin should remain undis- 
solved in the refuse of the opium and never pass into solu- 
sion. 
II. The separation of the Meconic acid. This should 
se effe@ed at an early stage of the process, so as to pre- 
vent the formation of a basic meconate on precipitation 
»f the Morphia, which is very apt to occur unless all the 
Meconic acid is separated in the first instance. 
The other conditions are rather details of the process 
‘han definite maxims, and are better included in the de- 
scription of the method than apart from it. 
Two special reagents are required in this process. The 
one prepared by mixing 1 part of solution of ammonia 
sp. gr. 0'880 with zo parts of methylated alcohol, or of 
unmixed alcohol, and digesting in this mixture a large ex- 
cess of Morphia for several days, with frequent agitation, 
so as to saturate it with Morphia. This may then be 
filtered for use when it will contain 0°33 per cent of Mor- 
shia, and for convenience sake may be termed * Morphiated 
Spirit.” The other is, Water saturated by frequent and 
ong continued agitation with excess of Morphia and then 
fitered, which may in its turn be called “ Morphiated 
Water,” containing 0-04 per cent of this alkaloid. It must 
se assumed that the sample of Opium to be examined has 
seen properly drawn, and prepared by kneading and rolling 
:ogether in a cool place ; but this is best left to a skilled 
sampler, who is known to be competent to and careful in 
1is work. ‘ 
PROCESS. 
1000 grains of Opium are macerated for twelve to twenty 
hours in about 4000 grains of cold distilled water, together 
To be continued.)