510 



ixotato is grated down, all these cells are broken, because of their perfect 

 cohesion to one another. One cell cannot be broken without breaking 

 all. But in the case of rotting potatoes, the nitrogenous cell which binds 

 the three together is partly removed by the fungoid action, but jxriiici- 

 jTj,^ 05 ]>ally by inrusoriallire(irtc'ten«,) 



which live on it. The inner or 

 center cell containing the starch 

 is thereby liberated. Its buoy- 

 ancy is so great it floats the 

 starch in the water. All starch 

 in perlect ceils is, therefore, 

 washed away in the manufac- 

 ture. 



M. Payen, as early as 1840, in 

 a paper read by him before the 

 Paris Academy of ScienceSj 

 stated that the starch ot ]>ota- 

 toes affected of fungi is tiot in- 

 jured, and during the present 

 year Dr. Hooker, of the Kew 

 Gardens, London, has, after a 

 microscopic examination, made 

 a public statement to the same 

 eliect. Starch manufactuiers^ 

 on the other hand, have stated 

 ill the columns of the English scientific monthlies that, while they do not 

 deny the statements of these scientists, they affirm that a large portion 

 of the starch of rotting potatoes will nut sink, and is consequently washed 

 away. These microscoj)ic observations explain the discrepancy between 

 the savans and the practical manufacturers. To overcome tfiis'difficulty, 

 I placed a portion of the rotting ))otato in a muUer, and ground it into a 

 very fine pulp. I next placed the pulp into water. After twenty-four 

 Pi (,._ 26. hours 1 examined microscopic- 



ally the precipitate and the whit- 

 ish matter i3oatingin the column, 

 of water. I fonud the whitish 

 substance to be cellulose, or 

 broken «ells, while the precipi- 

 tate vvas pure starch, showing, 

 that the starch had escaped from 

 the cells by the extra friction. 

 In order, then, to save all the 

 starch of rotting potatoes, it is 

 only necessary to grind them 

 with such improved machinery 

 as will reduce the potatoes to a 

 finer pulp. Martin McKinzie, of 

 Boston, wrote to the Depart- 

 ment, under date November 1, 

 ultimo, stating that, in a field 

 near his residence, Early Eose 

 and Jackson White potatoes 

 were planted this last season adjoining each other ; the first. Early 

 Rose, proved nearly an entire failure from blight — fungus; while the 

 second, or Jackson Whites, grew to perfection. Not the slightest appear- 

 ance of blight was manifest in any instance on them. The writer further 



