883 



cent, dry matter, the least ripe 24; starch varies from 14'08 to 20*71 

 per cent. ; fat 24 to 1 ; protein compound, in wet state, maximum, 

 3'75 per cent. Thus giving 15 per cent, protein compound in the 

 dry material. He adds, " In potatoes attacked with the prevailing 

 disease, the proportion of protein compounds diminishes ; they are 

 partially decomposed, producing ammonia and other compounds." 

 Also, " The proportion of protein compounds, chiefly coagulated 

 albumen, in the potato fibre, is greater, one would suppose — the main 

 being found by Fromberg to be 3j to 4 per cent. The fibre of the 

 potato, as he had already said, retained a protein of starch and other 

 nutritive matter, and, therefore, the real quantity of indigestible fibrous 

 or woody matter, is by no means so great as the per centage of fibre 

 appears to represent." Thus it was clear that the quantity of protein 

 compounds in the potato was much above what had been generally 

 supposed ; and it was to be recollected that the whole dry matter of 

 the potato was capable of being converted into a food for man, was 

 more fitted for storage than the great portion of the dry matter of 

 wheat — bran — was lost ; and the principal proportion of the flour of 

 wheat now used does not contain more than about 10 to 11 per cent, 

 of the protein compounds, while the best flour would not average 

 9 per cent. He (Mr. Rogers) would therefore strongly urge on the 

 Botanical Society of London the absolute duty, incumbent upon all at 

 the present juncture, particularly those to whom the public look for 

 instruction and guidance, to thoroughly investigate the question, and 

 pronounce a public opinion upon it. For the last few years it had 

 been the fashion to cry down the potato, and absolutely recommend 

 its abolishment; but the fallacy had been sadly proved, and they 

 should now seek to ascertain its real value. To his theory of the 

 cause of the disease of the potato, viz., "Constitutional weakness, 

 caused by unnatural growth in the pit, and that weakened and 

 degenerated parentage must produce diseased offspring," he would 

 request attention and investigation ; also to the remedy, namely, 

 " To sow when nature sows in autumn, and to re-invigorate 

 the weakened seed, by giving freely to the soil, carbon ; and let it thus 

 draw back, at once, means to reproduce the life-blood it had lost." 



Mr. Rogers's paper was throughout listened to with attention. 

 A long and animated discussion followed, in which Dr. Ayres, 

 Dr. Bossey, Dr. Cooke, and other members, joined. Various 

 donations were announced, and members elected ; and thanks having 



