276. Opium is one of the most valuable medicines we possess when properly employed, but as it is very powerful in its operation, it may be productive of _great mischief if used without care and caution, or in unsuitable cases_. 277. The Opium procurable in the bazaars is always more or less adulterated, hence the quantity procured in one shop is sufficient to procure a good sleep whilst the same quantity procured at another shop will perhaps produce no sensible effect whatever on the system. This shows the necessity of _great caution_ in its employment. 278. The uncertainty which attends the operation of bazaar Opium leads me to recommend that establishments at out-stations should be always provided with a supply of genuine Smyrna or Turkish Opium imported from Europe. It seems advisable to have it in two forms—_a._ In 1 grain pills, done up ready in an impermeable covering, like those sold by Kirby and others; by keeping it in this form it is always ready for an emergency. _b._ In the form of Tincture, LAUDANUM, which is a very convenient form when small or fractional doses of Opium are required, or when it is desirable to obtain a _speedy_ effect. Fifteen minims contain one grain of Opium; this holds good, however, only with recently prepared or carefully preserved laudanum. It should be borne in mind in all hot climates that evaporation of the spirit constituent will take place even in well stoppered bottles, and that in proportion as this evaporation takes place, the strength of the tincture is _increased_, so that in long kept Laudanum ten minims, or even less, may contain a grain of Opium. Hence, in using old Laudanum it is advisable to commence with smaller doses than in that recently prepared; the dose can be subsequently altered according to the effect produced or desired. 279. Preparations of Opium should always be kept _under lock and key_, or they may disappear at a rate which cannot be accounted for by evaporation or the heat of the climate! Opium in all its forms is a temptation which few natives have moral courage enough to resist. 280. The preparations of Opium mentioned above should be reserved for internal administration; for external application, where uniformity of strength is of comparatively little consequence, bazaar Opium may be employed, but even here it is desirable that good specimens of the best kinds should be used. A few additional observations on this point may be acceptable. 281. Of the several kinds of Opium met with in India the chief are: