HARDWICKE'S SCIENCE-GOSSIP. 



moisture to the substance of the wood, which com- 

 mences its course of decay so much below the original 

 surface, instead of at the surface. Had it commenced 

 at the surface, all the time occupied in decaying down 

 to the depth of the charring would be gained, sup- 

 posing that the decay commences at the surface, and 

 proceeds gradually inwards. The subject is one of 

 considerable practical interest, and worthy of careful 

 investigation. 



Another Source of Alcohol. — During 1884, 

 1826 pipes of alcohol, having a value of ,£40,518, was 

 made from the sweet potato in the Azores, and ex- 

 ported to Lisbon for fortifying wine. Subsequently, 

 the production has increased, and is still increasing. 

 The West India Islands being specially suitable for 

 the cultivation of the sweet potato, the development 

 of a new industry is anticipated there. A French 

 chemist connected with Martinique has taken up the 

 subject, but finds that the storage of alcohol in hot 

 climates, and its carriage in large quantities through 

 the tropics, is very dangerous. At 95 Fahr. it gives 

 off vapour so rapidly, as to be practically an ex- 

 plosive. 



He therefore proposes to desiccate the flour of this 

 potato, and export it in that state to Europe. He 

 says, referring to what has been already done at the 

 Azores, " The alcohol, of which we have specimens, 

 is superior in quality to the best marks of France. 

 The distillery obtains 12 per cent., i.e. 12 litres of 

 alcohol per ioo° kilog. of sweet potato." Also that 

 he has experimented on the sweet potato of Algeria, 

 which gives 13*4 per cent. ; that of Martinique and 

 Brazil, 15 per cent., while ordinary potatoes only 

 yield 3 per cent. Barley of 20 francs' value produces 

 25 litres, while an equal value of sweet-potato flour 

 yields 39. 714 lbs. of maize are required to produce 

 22 gallons, while this quantity is obtainable from 

 519 lbs. of sweet-potato flour. Alcohol made from 

 maize costs 10 francs per hectolitre (22 gallons) 

 more, and sells for 8 to 10 francs less than the same 

 quantity of sweet-potato spirit. It is anticipated 

 that the sugar planters of Jamaica will take up the 

 enterprise, the sugar bounties of our Continental 

 neighbours having severely depressed their original 

 industry. If so, a curious retaliation will fall upon 

 France by the extinction of its cognac, and other so- 

 called brandy trade. Once upon a time, eau-de-vie 

 and cognac were synonymous. Now, it is very dif- 

 ferent. Fortunately for us, our beverage interest in 

 alcohol is steadily diminishing ; but, concurrent with 

 this, is a continually increasing demand for alcohol in 

 chemical manufactures. 



Prehistoric Art. — The paper read on 22 Nov., 

 by M. Albert Gaudry, before the Academy of Sciences 

 of Paris, on the Montgaudier Cave (in the Charente 

 district), is interesting on account of the artistic 

 fragments it has brought to light. Pieces of ivory, 



embellished with carvings of aurochs and other 

 animals, are described as having been thus orna- 

 mented at a period when the cave-dwellers were still 

 stru gglmg for existence with the mammoth, the cave- 

 bear, cave-lion, large hyena, and rhinoceros. Patriotic 

 Frenchmen may claim that this is evidence of the 

 artistic superiority of their prehistoric ancestors, and 

 also of the dominant force of heredity. It also 

 indicates a certain amount of progress already made 

 by these people, sufficient to carry them far beyond 

 " the missing link." Brit we must not forget that 

 savages generally are artists — (please to understand, 

 gentle reader, that I do not predicate the converse) — 

 that clubs, paddles, and other weapons and imple- 

 ments are carved even by the rudest of existing 

 human beings — some of them very elegantly. 



When buying some spoons made of reindeer-horn 

 from the Lapps of the Tromsdal, I found on the bowl 

 of one of them a well-executed drawing of a reindeer, 

 all the peculiarities of ,the animal more correctly 

 delineated than in some of our book illustrations. 

 On inquiry, I learned that it was the work of a lad of 

 twelve or thirteen years of age, who was the proprietor 

 of a lead pencil, and had consequently become an 

 artist. 



THE ECONOMICAL PRODUCTS 

 PLANTS. 



OF 



THE Poison Oak, Poison Ivy, or Poison 

 Sumach.— These are the various aliases 

 applied to Rhus toxicodendron, Linn. (Fig. 4) which 

 is a native of North America, having, according to 

 some authorities, been introduced into this country as 

 early as 1640, and it was well known to the older 

 botanists ; while other authorities state that it was 

 first brought into notice in this country in 1793 by 

 Dr. Alderson, of Hull, when he was following up the 

 experiments of Du Fresnoi, made at Valenciennes ; 

 but I should say it was introduced much earlier than 

 the latter date, although at present I have found no 

 well-authenticated account of its introduction, and 

 there is a large amount of difficulty experienced in 

 tracing the history of introduced plants, owing to the 

 scantiness of reliable records. 



It is a small shrub, only a few feet in height. 

 Leaves on long petioles, trifoliate ; leaflets broadly 

 ovate or rhomboidal, acute, slightly pubescent, 

 entire or irregularly toothed or lobed (the illustration 

 shows the entire form of leaflet) ; it is one of the 

 most variable species in this respect. Flowers very 

 small, produced in axillary racemes, greenish-white, 

 dioecious ; male flowers with fine stamens, and a 

 rudimentary style ; female flowers with fine abortive 

 stamens, and a globose ovary ; fruit roundish, pale 

 green, of no value commercially. The tree through- 

 out possesses excessively varied and narcotic proper- 

 ties ; even its gaseous emanations produces very 



