Naturalisation in Extra-Trqpical Countries. 46& 



regions free from frost. In rich coast-lands of Victoria as much as 

 14 tons of potatoes have been taken from an acre in a single harvest. 

 As a starch -plant, the potato interests us also on this occasion 

 particularly. Prof. J. H. Gilbert points out, that although richly 

 nitrogenous manures promote much the growth of the Potato-plant r 

 yet the tubers get mainly enriched in starch only. Water, in which 

 potatoes have been boiled, serves against slugs and aphides [H. G. 

 Pratt]. Considering its prolific yield in rich soil, we possess as 

 yet too few factories for potato- starch. This starch, irrespective of 

 its many other uses, is preferentially' chosen for calico-printing. 

 The average yield is 10 per cent. Great Britain imported, in 1884, 

 about 14,000 tons of dry yeast, for the manufacture of which potato- 

 starch is largely used, at a value of 777,000. The starch, by being 

 heated with mineral acids or malt, can be converted into dextrin 

 and dextro-glucose for many purposes of the arts. Dextrin, as a 

 substitute for gum, is also obtainable by subjecting potato-starch 

 in a dry state to a heat of 400 F. Prof. Max Cornu recommends 

 syringing with a solution of sulphate of copper (1 to 200) against 

 Peronospora infestans. Alcohol may be largely produced from the 

 tubervS. The berries and shoots contain solanin. Baron von Liebig 

 remarks, " So sar as its foliage is concerned, it is a lime-plant ; as 

 regards its tuber, a potash-plant." Langethal says, "It surpasses 

 in easy range of cultivation all other root-crops ; its culture sup- 

 presses weeds and opens up the soil, besides preparing the land for 

 cereals." Seeds of the potato-berries should be sown in adapted 

 places by explorers of new countries, provided the natives can be 

 made to understand, that the berries are poisonous. The most 

 formidable potato-disease of the last forty years, from the Peronos- 

 pora infestans. seems to have originated from the use of objection- 

 able kinds of guano, with the introduction of which the murrain 

 was contemporaneous ; along with this Fung the Fusisporium 

 Solani works almost constantly its mischief also ; to destroy their 

 hibernating spores all vegetable remnants on potato-fields must be 

 burnt [W. G. Smith]. The foliage of potato-plants, when thickly 

 placed under trees or shrubs, infected by blight, checks materially 

 the spread of insects, which cause the disease. The most destruc- 

 tive potato-grub is Lita Solanella. The Colorado-beetle, injurious 

 to the potato-crop in North- America, is Doryphora decemlineata. 



Solanuxn Uporo, Dimal. 



In many of the islands of the Pacific Ocean. This shrub has 

 proved hardy at Port Phillip. The large red spherical berries can 

 be used like tomatoes. The leaves, macerated in cold water, render 

 it quickly mucilaginous, and the liquid thus obtained is regarded 

 as valuable against dysentery [Rob. MacDougall]. 



Solanum vescum. F. v. Mueller. 



The Gunyang. South-Eastern Australia, extending to Tasmania. 

 A shrub, yielding edible berries, which need however to be fully 

 ripe for effecting absence of deleterious properties. 



