Naturalisation in Extra- Tropical Countries. 69 



ton. In climates, not subject to frost, the beet-harvest can be 

 extended over a far greater portion of the year than in Middle- 

 Europe. The extraction of the sap is eff ected generally by hydraulic 

 pressure ; the juice is purified with lime and animal charcoal ; excess 

 of lime is removed by carbonic acid, and the purified and decolorised 

 juice is evaporated in vacuum-pans, with a view to prevent the 

 extensive conversion of the crystallisable sugar into treacle. The 

 production of beet-sugar needs less labor than that of cane- 

 sugar ; also the harvest is obtained in so short a time as eight 

 months. The beet has shown itself subject neither to fungus- 

 diseases nor to extensive attacks of insects. It is mostly grown in 

 extra-tropical zones, while the sugar-cane is confined to tropical 

 and sub-tropical latitudes. Beet-culture, by directly or indirectly 

 restoring the refuse, ameliorates the soil to such an extent, that in 

 some parts of Europe land so utilized has risen to four-fold its 

 former value. The beet furthermore affords one of the most fatten- 

 ing stable-fodders ; and thus again an ample supply of manure. 

 In the beet-districts of Middle Europe about one-sixth of the arable 

 land is devoted to beets, yet the produce of cereals has not been 

 reduced, while the rearing of fattened cattle has increased. Not- 

 withstanding a heavy tax on the beetsugar-factories in Europe, the 

 industry has proved prosperous, and assumes greater and greater 

 dimensions. In 1865 the sugar consumption of Europe amounted 

 to 1,583,825 tons, one- third of which had been locally supplied by 

 the beet, from over one thousand factories. Treacle obtained from 

 beet is distilled for alcohol. For establishing remunerative factories 

 on a large and paying scale, it has been suggested, that farmers' 

 companies might be formed. For ascertaining the percentage of 

 sugar in the beet, saccharometers are used. In Germany some 

 scientific periodicals are exclusively devoted to the fostering of this 

 industry. In 1875 the total production of beet-sugar amounted to 

 1,318,000 tons [Boucheraux]. In 1882 fully 38 per cent, of the 

 world's supply of sugar was derived from the beet. The beet-sugar 

 crop of 1886 in all Europe was estimated at 2,500,000 tons. During 

 1886 the import of unrefined beet-sugar into Britain was 333,590 

 tons, valued at 3,988,534, irrespective of the import of refined. 

 The present production of beet-sugar amqunts to about 3 million 

 tons (1,650,000 tons in Germany and Austria) more than the total 

 of the cane-sugar now produced. 



Be tula acuminata, Wallich. 



Himalaya, between 3,000 and 10,000 feet. Attains a height of 

 60 feet, and thrives along forest-streams. The wood is hard, strong 

 and durable. Another Himalayan Birch, B. utilis (D. Don), grows 

 on arid ground, and produces good timber of less hardness. 



Setula alba, Linne. 



" White Birch." The common Birch of Europe and Extra- 

 tropical Asia and North-America. With some Willows approach- 



