394 TRANSACTIONS OF THE 



this root, there is a combination of azote which does not exist in 

 the common potato, and which augments in an eminent degree 

 its nutritive character. The experiments made in France, and 

 in Algeria greatly assimilate in their analysis, and they both pre- 

 sent the characteristics of this root, as alimentary in the highest 

 degree. The primary constituents of the Chinese potato are essen- 

 tially those of the common potato, and if there is a small degree 

 less of starch in the Chinese root, it is most amply compensated 

 by the azote^ which is very remarkably combined, and which I 

 must here state is a most astonishing constituent, and cannot fail 

 to exercise a most happy and important influence on this estima- 

 ble plant whose qualities are now submitted to our examination. 

 The mucilaginous principle of this root approaches to albumen, 

 in consequence of the combined azote, and coagulates by heat. 



The Chinese potato cut into sections and dried by a stove 

 attains such a condition that it may be reduced to a powder, and 

 then, by the addition of water, it forms a dough closely assimi- 

 lating to that made from wheat flour. 



We do not assume that the azote in this root is equivalent to 

 the gluten contained in wheat flour, but we urge special attention 

 to the point, that this root can enter to a certain degree into the 

 manufacture of bread. The chemical analysis demonstrates to us 

 the close relation which exists between this root and our com- 

 mon potato, and by the greater nutritive qualities of the Chinese 

 root, we elucidate the cause why it enters so largely into the 

 consumption of the Chinese Empire.." 



"With these remarks of Prof. Decaisne, I will now proceed to 

 give the results of my own experiments. During the years 1849 

 and 1850, my attention and that of many other Americans then 

 at San Francisco was attracted to the importation from China, by 

 the emigrants, of numerous bags of a root resembling the sweet 

 potato, which had been cut into sections and apparently kiln- 

 dried. These roots were ground or pounded by the Chinese and 

 made into l)read. 



On my return home I found, on perusing the French periodi- 

 cals, that Mons. Montigny, the French consul in Northern China 

 had sent to the Royal Institute at Paris a root correspoiitling to 

 that which I had seen at San Francisco, and I took measures to 

 procure some specimens. It was impossible to obtain a full 

 grown root at any price, but in the course of two months I 

 received some small weak tubers, less in size than a pea. These 

 I planted and cultivated with care, and was greatly amazed to 

 find in the autumn that they had formed roots 18 to 24 inches in 



