838 APPENDIX. 
place ; and this is the only instrument which enables us to determine 
the per centage of uncrystallizable or grape sugar. It is, therefore, 
to the polarizing saccharometer that we must look to determine this 
important point. But supposing the entire sugar to be crystallizable, 
the hectare would give the following result : *3.25° x 67 = 53177 x 
13 = 7254 kilogramme of sugar, or the equivalent for one portion of 
uncrystallizable sugar. . 
The sap containing grape sugar, or uncrystallizable, is not less sus- 
ceptible of alcoholization than if it had none but crystallizable. But 
I will again refer to this matter. 
The stalks which had been robbed of their seed heads having been 
left standing in the field, I had the satisfaction to see them two months 
after the gathering of the seed still standing, untouched by the wind, 
and safe frem the attacks of worms, and, moreover, retaining their 
original sweet taste. ‘Thus we see that not only does the sweet prin- 
ciple develop itself at the time of ripening the seed, but it continues 
to exist, unchanged, in the stalks long after the seed tops are removed ; 
and it isabsolutely proved that in Algeria we may use the seeds of the 
sorgho when they are fully ripe, without Jessening the crop of the sac- 
charine matters contained in the stalk. 
The sorgho seed has at present an inordinate value, because of its 
rarity ; but this will be but of short duration, and the price will rap- 
idly descend to a level with the ordinary cereals, the yield being so 
very prolific as to quickly surpass even the most unusual demands for 
planting: 
Besides the foregoing uses, this seed will bear a certain industrial 
value, and have other employment than the rearing of poultry or pigs, 
like the seed of the broom corn. Doctor Sicard, of Marseilles, has 
discovered, during the past year, that the seed of the sorgho sucré 
contains in the outer coating a very beautiful red color, from which 
he has obtained all the various tints ranging from red to violet. M. 
Chevreul has likewise noticed the remarkable and entirely character. 
istic facility of this dye for tinting silk.* 
* I have repeated the experiment of Dr. Sicard and M. Chevreul with entire success. 
The hulls, stripped from the seed, and boi'ed for about fifteen minutes in pure water, 
yield a deep purplish red solution, in which I have dyed cotton and silk fabries. The 
tints range from deep purple to a splendid opal. The dye, I find on microscopic exam: 
