156 INDEX. 



should be isolated, 123 ; remedies against propagation of, ib. ; 

 small sets recommended, 124 ; production of fibre essential, ib. ; 

 means of inducing development of fibre, ib ; remedies against 

 consequences of, 125; starch available, ib. ; no chemical remedy 

 of use, 126 ; drying, ib. ; cold dry atmosphere best preservative, 

 ib. ; probable means of lessening, 142. 



Potatoe plant, general description of, 1, 6, 139 ; root and leaf essen- 

 tial parts of, 6 ; individuality of, 6, 15 ; seedlings are individuals, 

 7 ; mode of obtaining new varieties, ib. ; duration of life of an 

 individual, 8; probably limited, ib. ; belongs to a poisonous fa- 

 mily, and is itself poisonous, ib. ; first figured by Gerard, ib. ; 

 description of, by Gerard, ib. ; various accounts of its original 

 source, ib. ; does not grow wild in North America, 9 ; grows 

 wild in Chili and Peru, 10 ; wild plants at Chelsea and Chiswick, 

 12,13; resist the disease, 43 ; number of varieties, 13,14; proba- 

 ble source of our varieties, 14; mode of continuing varieties, 15; 

 the varieties in use are deviations from the natural plant, 112, 



' 139; tubers of wild potatoe brought into this country lately, 11, 

 14 ; minute description of plants and produce of the wild tubers, 

 12, 14; analysis of, 16 ; fruit used as a pickle, 26 ; effects of tem- 

 perature on, 47 ; of light, 48 ; of electricity, 49; of drought and 

 moisture, 49, 50 ; of atmospheric changes, 52 ; soil best adapted 

 for, ib. ; attacked by the Aphis vastator, 68 ; mode of attack, 69, 

 72 ; attacked by other diseases, 108 ; curl, ib. ; description of, 

 103, 109 ; probably owing to Aphides, 110 ; rust, ib. ; amount of 

 deficiency of crop in 1845 and in 1846, 132 ; affords more ali- 

 mentary matter than any other plant, 138 ; facility of cultiva- 

 tion, ib. 



Rare insects unusually common in 1846, 101. 



Rose-trees attacked by an Aphis, 94. 



Rust on potatoe plant, 110. 



Rye a substitute for other grain, 132. 



Salter, Dr., first noticed the potatoe disease in England, xxvii. 



Scarcity in 1845 and 1846, 132; amount of, ib. 



Schlossberger and Kempt's table of nitrogen in varieties of food, 21. 



Shepherd's purse attacked by the Aphis vastator, 89. 



Soil, its influence on the disease, 52, 53. 



Solanine, 17, 18; analysis of, 18. 



Solanaeae generally preferred by the Aphis vastator, 85. 



Solanum dulcamara attacked by the Aphis vastator, 84 ; nigrum at- 

 tacked by the Aphis vastator, ib. 



Southwell, Sir Robert, his account of the introduction of the po- 

 tatoe, 9. 



Spiders destroy Aphides, 106. 



Spinach attacked by the Aphis vastator, 81 ; mode of attack, 82; 

 effect of rain on the disease in, 83. 



Spurge attacked by the Aphis vastator, 89. 



Starch, its source and uses in the potatoe plant, 4 ; state in which 



