Naturalisation in Extra-Tropical Countries. 569 



in 1889 nearly 28 million Ibs. To obtain good raisins the grapes 

 must be perfectly ripe and their sap should contain at least 25 per 

 cent, of saccharine principle. In dry parts of California the drying 

 process is effected solely by sun-heat, the time required from gathering 

 of the grapes to drying being rather less than two weeks. A slight 

 sweating is then caused to attain equality in the maturity of all the 

 raisin-berries ; this is done in boxes placed into a dark closed room 

 and takes two weeks more. In 1891 California produced 2,611,590 

 cases of 20 Ibs. each [Paul Grallert]. 



The Corinthian variety, producing the currants of commerce, also 

 thrives well in some districts of extra-tropic Australia, where with 

 raisins its fruit may become a staple-article of export beyond home- 

 consumption. The Sultana-variety is not to be much pruned ; the 

 bunches when gathered are dipped in an alkaline liquid obtained from 

 wood-ashes, to which a little olive-oil is added, to expedite drying, 

 which is effected in about a week [G. Maw]. The produce of 

 Sultana-raisins fluctuates from 7 to 30 cwt. per acre. The plant 

 is best reared on limestone-formations. In Greece the average-yield 

 of ordinary raisins is about 2,000 Ibs. per acre [Simmonds]. Besides 

 the Sultana also Muscat of Alexandria and Malvoisie a gros grains 

 are used for good raisins. By continued crossing of the Sultana- 

 variety, perhaps other seedless kinds might yet be originated. Britain 

 imported in 1889 1,173,000 cwts. of currants valued at 1,420,000, 

 and 573,000 cwts. of raisins, valued at 910,000. The currants im- 

 ported into Victoria in 1887 were valued at nearly 80,000; raisins 

 36,000 ; since then however the local production of raisins has 

 largely increased. Australia has lately also become a producer of 

 pure grape-brandy. In 1892-3 the area planted with vines in the 

 colony Victoria was 28,000 acres. An extensive special work of 

 great value on the raisin-industry has been issued in 1890 by Pro- 

 fessor Gustav Eisen, in San Francisco. Dr. W. Hamm, of Vienna, 

 has issued a Vine-map of Europe, indicating the distribution of the 

 different varieties and the principal sources of the various sorts of 

 wine. The writer would now merely add, that the preservation of the 

 grapes in a fresh state, according to M. Charmeux's method, and the 

 sundry modes of effecting the transit of ripe grapes to long distances, 

 ought to be turned to industrial advantage. The Almeria-variety has 

 lately been introduced by the South- Australian Government ; this 

 kind is distinguished for keeping well, and is largely sent from Spain 

 to the English market [Dr. Muecke]. The pigment of the dark wine- 

 berries is known as racemic acid. The juice contains along with 

 tartaric acid also grape-acid. Tartrate of soda (Rochelle Salt) and 

 some other chemical bases can be produced even from vine-leaves [R. 

 Fletcher]. All these chemically denned substances have uses of 

 their own in art and science. As is well known, the grape-vine is 

 subject to the attacks of various insect- and fungus-pests. The most 

 destructive by far is the insect called the Phylloxera vastatrix. None 

 of the remedies hitherto suggested seem to have proved really effec- 

 tive, or they are not of sufficiently easy and cheap application, and 



