By mixing assayed samples he is able to produce an opium containing uniformly 10% of morphia.
Angora opium is met with in small smooth pieces, has generally a pale paste and is rich in morphia.
This is in some measure due to the fact that Indian opium contains less morphia.
Although the cultivation of opium in Persia was probably carried on at an earlier date than in India, Persian opium was almost unknown in England until about the year 1870, except in the form of the inferior quality known as " Trebizond," which usually contains only 0.2 to 3% of morphia.
Experiments made in Germany by Karsten, Jobst and Vulpius have shown that it is possible to obtain in that country opium of excellent quality, containing from 8 to 13% of morphia.