INDEX. 155 



Phosphorus contained in the potatoe, 22. 



Phosphorescence, instances of, 22. 



Plantain attacked by the Aphis vastator, 89. 



Plusia gamma, increase of, in 1735, 98. 



Potatoe, early opinions concerning, 9 ; named from its resemblance 

 to the sweet potatoe, ib. ; not to be confounded with the sweet 

 potatoe, 15 ; name mentioned by Shakspeare, ib. ; qualities of the 

 wild potatoe, 11, 14; analysis of, 17, 18; mode of analysis, 38; 

 is a sufficient source of nourishment for man, 20, 138, 143 ; com- 

 parative amount of nitrogen in, and in other substances, 20, 21 ; 

 quantity necessary to sustain life, 21 ; fowls will not feed on long, 

 22; contains phosphorus, ib. ; instances of phosphorescence, ib.; 

 contains iron, ib. ; modes of cooking, 23 ; domestic uses of, 23, 24 ; 

 may be made into bread, 23 ; in wheaten bread, ib ; use as a me- 

 dicine, ib. ; starch. See Starch. Distillation of spirit from, 25; 

 wine made from, 26 ; food for cattle, ib. ; mode of preserving by 

 the Mexicans, ib. ; extent of distribution, ib. : analysis of, in vari- 

 ous years, 39 ; consequence of depending solely upon, 139 ; illus- 

 trated in the Irish, ib. ; mischievous in a political point of view, 

 139, 144. 



Potatoe disease, 27 ; has existed in Germany since 1830, xxvii. ; is 

 mortification or gangrene, 27, 141 ; commences at various parts of 

 the plant, 27 ; various modes and localities of attack, 28, 30 ; fre- 

 quently attacks the collar, 29 ; various modes of death of the 

 plant, ib. ; causes an offensive odor, 30 ; probably connected with 

 the sap and cellular tissue, 33 ; probably affects every part of a 

 diseased plant, 34 ; attack commences at all ages and stages of 

 growth, ib. ; variety of effects upon the tuber, 34, 35 ; effects upon 

 the structure of the plant, 36; analysis of diseased tubers, 38, 39; 

 does not cause destruction of the starch, 39, 40 ; causes develop- 

 ment of sugar, and gives a proneness to putrefaction, 40 ; may 

 be produced in the produce of diseased tubers without the reap- 

 plication of the exciting cause, 34, 142 ; course of when it ap- 

 pears as gangrena sicca, 35 ; result of cutting the haulm, 36, 123 ; 

 attacks new and old varieties, 41 ; resisted by the wild plant, 42, 

 112; attacks varieties variously, 43 ; account of by Mr. Greatrex, 

 ib. ; by Mr. Storr, 44 ; by Mr. Latham, ib ; old age not the cause 

 of, ib.; early kinds less liable to, ib.; not caused by internal agency, 

 ib. ; by variations of temperature, 45 ; by variations of light, ib. ; 

 by electricity, ib. ; by excessive moisture or draught, 46 ; by other 

 atmospheric causes, ib. ; effects of heat and moisture on, 45 ; not 

 affected by soil, ib ; by manures, 54 ; by mode of culture, ib. ; re- 

 lation of fungi to, 55, 56; not caused by fungi, 56; relation of 

 insects to, 57 ; always preceded by the Aphis vastator, 72, 111 ; 

 mode of action of the Aphis vastator, 72, 1 12 ; caused by the Aphis 

 vastator, 111, 141 ; theory of, 112 ; will probably wear out, 113 ; 

 future prospects of, 115, 142; remedies for: employing early 

 kinds, 122 ; autumn planting, ib. ; contagious nature of, ib. ; crops 



