Experiments made in England, France, Italy, Switzerland, Greece, Spain, Germany, and even in Sweden, prove that opium as rich in morphia as that of Eastern countries can be produced in Europe.
Great care is now taken to prevent adulteration, and consequently Persian opium can be obtained nearly as rich in morphia as the Turkish drug - on the average from 9-12%.
The juice yields about one-fourth of its weight of opium, and the percentage of morphia varies according to the variety of poppy used, the purple one giving the best results.
Some specimens of French opium have been found by Guibourt to yield 22.8% of morphia, being the highest percentage observed as' yet in any opium.
It was found that the method yielding the best results was to make incisions in the poppy-heads soon after sunrise, to collect the juice with the finger immediately after incision and evaporate it as speedily as possible, the colour of the opium being lighter and the percentage of morphia greater than when the juice was allowed to dry on the plant.