326 ON THE CULTIVATION OF INDIGENOUS OPIUM. 
toxide of iron, which experience has proved to be very injurious to 
vegetation. 
Lastly, magnesian earths are rather grey or black and marly. They 
are all sterile, on account of the magnesia, which exercises over vege- 
tables a pernicious action. — E. Thirrids /Statistics of Hte+ Saone. 
So much being granted, let us now see what soils are suitable for 
the carnation poppy. 
After the numerous experiments that I have made on the various 
soils of three departments of France between 1860 and 1864, the 
result is, 
1st. That we must employ for this culture, as far as possible, choice 
lands with rich soil. 
2nd. We must reject strong earths or poor soils without depth or 
too arid ; as on these the poppy will not thrive nor yield much opium. 
3rd. The carnation poppy seems to like ferruginous earths. 
4th. It flourishes best of all in light or sandy soils which have a little 
depth ; in a word, it requires ground not too dry, and soil not too com- 
pact, for the root of this plant being pivoted it must perish in an un- 
penetrable or arid soil. 
5th. The nature of the ground must be chosen according to the 
aspect or situation of the sun. Therefore, in places exposed to the 
north we must reject cold earths ; poppies there give little opium, and 
the opium yields little morphia (8 per cent.) 
On the contrary, in places exposed to the south or on a plain, we 
must give the preference to cold earths, for then the water retained in 
the sub-soil furnishes a useful humidity which constantly tempers the 
heat of the sun. Poppies growing there furnish in abundance an opium 
rich in morphia (15 to 20 per cent.) I have had the best results at 
Grandchamp (Haute Marne), in sandy ground exposed to the south, 
belonging to the ferruginous class, and reposing on the marls of that 
degree. 
The carnation poppy there, acquired prodigious dimensions, and 
furnished abundantly a rich opium with 20 per cent, of morphia. 
I found it grow equally well in the plains of Haute Saone, on a 
reddish soil reposing on a clay containing iron. 
It also gave me equally good results, at Luxeuil, in a soil of motley 
grey, the superstructure of a clayey subsoil. 
From the preceding observations, and from analogy, it is easy to 
point out the land most suited to the cultivation of the carnation poppy 
in different climates. 
Thus, in the northern departments, with land situated in the plains, 
or on hilly ground facing the south, cold earths must be rejected. 
On the contrary, in the southern departments the preference should be 
given to land having a subsoil impermeable to water, and in still hotter 
regions land must be chosen upon rising ground exposed to the north, in 
order that the plants may be protected from the rays of a burning 
