182 



KNOWLEDGE. 



May, 1913. 



on the rocky cliffs of the Kuriles occur also in the alpine zone 

 of these mountains. 



The aquatic vegetation of the Middle Region shows great 

 diversity ; the genera, and many of the species are cosmo- 

 politan ; Isoetes japonica, one of the largest species of this 

 genus, frequently grows in running water instead of still lakes. 



(3) Southern Region. — Even at the northern limit of this 

 region, in Kyushu, the vegetation is quite sub-tropical. On the 

 coasts, washed by the warm current, various Indo- Malayan strand 

 plants are found; in the Loochoos, Bruguiera gymnove- 

 rhiza forms the mangrove forest in the tidal estuaries ; well- 

 developed mangroves are seen in Formosa, consisting of 

 Avicennia officinalis, Kandclia, Rhizophora, and so on. 

 Various palms belonging to the genera Arenga, Livingstonia, 

 Trachycarpus, and so on, nourish in this region, which may 

 be characterised as a region of Fiats, with which broad-leaved 

 evergreen trees and shrubs, such as various Lauraceae, Ouerciis, 

 Hibiscus, Myrica, and so on, are found. On their branches 

 are many epiphytic lycopods and ferns, and sometimes par- 

 asites (Loranthus and Viscum) are found, while in the dense, 

 moist forests there flourish many tropical ferns. 



In Formosa also the vegetation is typically tropical, with 

 abundance of huge trees, thick bushes, dense forests with 

 numerous woody climbers, and so on. In the mountain valleys 

 the camphor tree (Cinnamomum camphora) reaches great 

 dimensions; Macuna gigantea and Pusaetha scandens 

 (leguminous trees with enormous pods), other climbers, and 

 gigantic bamboos, tall tree-ferns, palms and Musa grow in the 

 forests and on mountain slopes ; while higher up on the moun- 

 tainswhichoccupythegreaterpartof the island, conifers are seen 

 at an elevation of two thousand metres. Chamaecyparis 

 formoscnsis. Cunninghamia, Konisliii, Picea morrisoni- 

 cola, and Pinus formosana are some of the interesting 

 trees, and are only known from this island, while a few years 

 ago a new conifer discovered here was placed in a new 

 genus (Taiwania cryptomerioides) ; and higher up we get 

 first the shrub zone, and then, at four thousand metres and 

 upwards, various alpine and arctic species of Arabis, 

 Artemisia, Cer ostium, Descliampsia, Festuca, Fragaria, 

 Gentiana, Luzula, Potentilla, Sibbaldia, and so on. The 

 flora of Formosa has some two thousand five hundred species 

 of vascular plants, seventeen per cent, of which are endemic, 

 and doubtless many more remain to be discovered. 



CHEMISTRY. 



By C. Ainsworth Mitchell, B.A. (Oxon.), F.I.C. 



UTILISATION OF MILK WEED.— The current issue of 

 the Journal of the Society of Chemical Industry (1913, 

 XXXII, 72) contains a paper by Dr. A. C. Neish, describing 

 experiments that have been made to discover uses for the 

 enormous quantities of this wild plant which are annually 

 wasted. The common milk weed (Asclepias syriaca) grows 

 abundantly on sandy or clay soil in the United States and 

 Canada. It produces a milky juice or latex, which yields from 

 two to three per cent, of rubber, but the amount is so small 

 and its quality so poor that its extraction would not be 

 commercially profitable. 



On the other hand the bast fibres of the plant are likely to 

 prove a more profitable product, for they can be readily 

 separated, and when bleached yield a white silky textile 

 material, which is stronger than flax, which in other respects 

 it closely resembles. The seeds also contain about twenty-one 

 per cent, of a drying oil which may be easily extracted with a 

 suitable solvent, while the down attached to the seeds is white, 

 very soft and springy and contains 0-9 per cent, of ash. It 

 could be utilised as an upholstering material, as has already 

 been done with the seed hairs of other species of Asclepias. 

 The woody tissue, about eighty per cent, of the plant material, 

 yielded, on treatment with soda solution under pressure, a 

 pulp from which paper of good quality could be made. From 

 the results of his experiments in general Dr. Neish considers 

 that it may prove practicable to start a new industry to 

 utilise the product of the common milk weed and similar 



plants of the same species, but some system of cultivation 

 would probably be required to supplement the supply of the 

 wild plants already available. Such a crop might be grown 

 upon dry or wet soils with which little else could be done. 



USE OF ALCOHOL AS A MOTOR FUEL.— The 

 "Times Engineering Supplement " for January 15th, 1913, 

 deals with the question of the substitution of alcohol for petrol 

 as a motor fuel. A comparison of the relative calorific values 

 of the two liquids showed that petrol of specific gravity 0-684 

 produced eleven thousand six hundred and twenty-four 

 calories per kilometre, while methylated spirit gave only six 

 thousand two hundred calories. In practice, however, this 

 superiority of petrol disappears. For example, in comparative 

 tests with the two fuels in specially constructed eight horse 

 power engines, it was found that 340 grammes of petrol were 

 consumed per horse power hour as against 373-5 grammes of 

 methylated spirit, showing that the relative efficiences were as 

 16-5 per cent, for the petrol and 28 per cent, for the alcohol. 

 The better results given by the alcohol are to be attributed to 

 the greater ease with which it is possible to obtain complete 

 combustion, and to the smaller proportion of air required. 

 In addition to these factors, it is possible with the use of 

 alcohol to obtain greater compression and a cooler cycle, both 

 of which conditions tend to economize fuel. 



Although denatured alcohol can be obtained free of duty, 

 its price is still as high as that of petrol at the present time, 

 and the reason for this is not the manufacturing cost, but the 

 charges made by the Government for supervision to ensure 

 that the spirit is not drinkable when it leaves the distillery. 

 A spirit containing about ten per cent, of crude benzene would 

 be undrinkable, and could be manufactured at a cost of about 

 sixpence per gallon, while only slight modifications of the 

 carburettor would be required to enable it to be used in 

 ordinary petrol motors. Hitherto efforts have been directed 

 to the perfection of the petrol engine, and it is possible that 

 when an equal amount of research has been given to discover 

 the best methods of using alcohol, the latter will be recognised 

 as the more suitable fuel. 



UTILISATION OF HORSE-CHESTNUTS.— Although 

 several attempts have been made during the last two centuries 

 to utilise the horse-chestnut in the preparation of detergent 

 preparations, none of them have been adopted as commercial 

 processes. As far back as the year 1757 it was discovered by 

 a Frenchman named Marcandier that the juices of this nut 

 had strong frothing and cleansing properties, and that they 

 could be used instead of soap for removing dirt and grease 

 from textile materials. . A similar use of horse-chestnuts was 

 known in Germany, as is shown by the account given in 1824 

 in a technical paper. 



After the lapse of years, the idea of using horse-chestnuts 

 for washing preparations has again come to the fore, and since 

 the year 1888 there have been several processes patented for 

 extracting the saponine or frothing substance from the nut. An 

 outline of the methods suggested, and a discussion on profitably 

 utilising the other constituents of the horse-chestnut, is given 

 by M. Rousset in the current issue of Les Matieres Grasses, 

 1913, VI, p. 2980. 



The kernel, after removal of the shell (which is rich in 

 tannin, and is utilised in the preparation of a tanning extract 

 for leather), contains the following proportion of extractive 

 substances: — Oil, 6-6: aesculic . acid, 3-2; carbohydrates, 

 10-8; reducing sugars, 5-2; gums, 1-2; and proteins, 1 • 

 per cent. 



The oil, which can be extracted with petroleum spirit, is 

 a pale yellow liquid with characteristics similar to those of 

 almond oil. After removal of the oil, the residue, when 

 extracted with dilute alcohol, yields an extract containing 

 about fifteen per cent, of aesculic acid, a substance of a 

 saponine character which has strong lathering and cleansing 

 properties. 



Finally, the mass left from the two extractions could be 

 used in the preparation of a white starch, which, after treat- 

 ment with cold water to remove a bitter principle, would be 

 quite suitable for use as a food, 



