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SCIENTIFIC NEWS. 



[Aug. 3, iJ 



describe it, formed by the commencement of the 

 branches. A little rustic door guarded the entrance 

 to this strange retreat, which was used by the Spaniards 

 of the island as a chapel for the celebration of 

 holy mass as far back as 1493. Although of such 

 wonderful antiquity, this tree flowered annually, 

 covering its entire crown with a perfect mantle of white 

 blossom, which presented a striking and most poetic 

 contrast to the gnarled and weather-beaten trunk 

 beneath. In 1819 a storm carried away about a third 

 of its branches, but did not seem to affect the 

 main structure very seriously. Unhappily, however, 

 this magnificent specimen of arboreal growth, this 

 living silent record of long-past centuries, was (accord- 

 ing to a statement by a recent writer) utterly destroyed 

 by a terrific hurricane in the year 1867. The largest 

 specimen now extant is, we believe, the one outside the 

 gates of the cemetery in the steep little village of Icco 

 del Alto in Teneriffe. As a writer in the Journal of 

 Forestry remarks, " The dragon tree has a grim, weird, 

 antediluvian appearance about it, suggestive of the idea 

 that it is a survival of ages past, and that it may have 

 witnessed the struggles for existence whose records are 

 written in the strata of the earth. It was an object of 

 Druidical veneration for centuries before Christianity 

 appeared on the earth, and the hollow trunks of some 

 of the trees were used by early Christians as a place of 

 worship." Tradition asserts that it was deeply revered 

 by the Guanchos, the ancient inhabitants of Canary Isles, 

 who apparently made use of the resin which they 

 obtained from it in the embalming of their dead, since 

 this resin has been found in their ancient sepulchral caves. 

 Humboldt induces this fact as a proof that the Guanchos 

 were not so completely isolated from the natives of Africa 

 and Asia as was commonly supposed, since these trees 

 originally came from India, a question, however, which we 

 have no space to discuss here. Wherever may have 

 been its original home, India or elsewhere, the dragon 

 tree has been cultivated since the most distant ages in the 

 Canary Islands, Madeira, and Porto Santo, and is now 

 never met with farther east than the Isle of Socotra. 



The Draccena draco is supposed to have derived its 

 popular name from a red resinous exudation from its 

 leaves and from cracks in its trunk, known in commerce 

 as " dragon's blood," which once formed a considerable 

 export from the Canaries, and which has even yet scarcely 

 fallen into complete disuse. Itwasformerly used inmedicine 

 as an astringent in dysentery, haemorrhage, etc., but is 

 now scarcely recognised by modern druggists, who use 

 instead the resin of Pterocarpus draco, a large South 

 American tree, although that also is now almost out of 

 date, having been superseded by the more modern dis- 

 coveries and inventions which flood the market in medi- 

 cine as well as in aught else. The true dragon's blood, or 

 gum dragon, of the present day is mostly obtained from 

 the fleshy fruits of an East Indian palm, the Calamus 

 draco, a native of India, Sumatra, the Moluccas, Malay 

 Islands, etc. It is an opaque, reddish-brown resin, 

 brittle and smooth, with a shining shell-like fracture. 

 When burned its odour somewhat resembles that of 

 benzoin ; it is almost insoluble in water, but is soluble 

 in alcohol, and the solution thus obtained is used as a 

 permanent stain for marble, leather, wood, etc., and for 

 colouring various tinctures, dentifrices, etc. It is also 

 soluble in oil and turpentine, and in this form is used as 

 a colouring ingredient in clear spirit and turpentine var- 

 nishes ; and it is used in the preparation of gold lacquer. 



Another variety of this gum dragon is said to be yielded 

 by the red sandal wood tree {Pterocarpus santalinus) of 

 the East Indies, and a somewhat similar substance by the 

 Dalbergia monetaria, a tree of the same order indigenous 

 in Guiana. An astringent resin is obtained from the 

 Eucalyptus resinifera of New Holland, which is known 

 there by the same name of dragon's blood, and in 

 Mexico another resin of the same kind, obtained from 

 the Croton draco (of the order Euphorbiacecz) is still ex- 

 tensively used in medicine. 



A New Silk-worm. — Among the silk-producing 

 insects of India Cricula trifenestrata should not be over- 

 looked. It is noticed by Mr. Wardle as being very 

 common in Assam, where it is known as the Haum- 

 pottonee. It feeds on the " soon " tree, forming an open 

 net-like cocoon of a beautiful yellow colour and of a 

 rich lustre. The silk is spun in the same manner as 

 that of the " eria " cocoon (Attacus riciui). It is also 

 met with in Moulmein, where the caterpillars are said 

 to feed upon the cashew-nut tree (Anacardium Orientale). 

 This silk-worm is very productive, there being two 

 generations in each year. According to Dr. O. Witt, of 

 Berlin, it yields an excellent fibre, and is likely to 

 prove of importance in the silk trade. 



An Advocate of Parasitic Vermin.— According to 

 the Medical Press, a Mr. James Grahame actually said in 

 an address to the students at the Glasgow Hospital for 

 Skin Diseases that " the parasites which irritate the 

 cuticle were sent by a beneficent Providence to promote 

 that necessary surface excitement required by the skin, 

 and were not altogether without a beneficial influence 

 on the health of the community ! " 



Stature of the Extinct Irish Elk, Cervus megaceros. — 

 According to a writer in the Field the two largest skeletons 

 of this species known (in the Science and Art Museum, 

 Dublin) are respectively 6J feet and 6^ feet at the 

 shoulders, the spread of the antlers being 9 feet 2 inches 

 and 11 feet 7 inches. Sir J. Ball states that this species 

 occurred not only in the British Islands, but extended to 

 the eastwards as far as the Altai. Ireland was probably 

 its most recent locality. 



A Strange Migration. — The Red Admiral butterfly, 

 which is generally said to be much scarcer in the South 

 of England and in the Midlands than was formerly the 

 case, is becoming very abundant in the North of Scotland. 



Hysteria in a Dog r 1 — Mr. T. Byron Place mentions, in 

 the Field, that a greyhound bitch suffered for about a 

 month from what seemed to be paralysis. She was 

 unable to move her head, and the whole body was rigid. 

 Whilst on the lawn one day a rabbit started ; she imme- 

 diately followed in pursuit, jumped down the sunk fence, 

 and fell head over heels. She got up perfectly well. 

 This seems to be an instance of the class of recoveries 

 known as " faith cure," " scare cure," or " excitement 

 cure," according to the kind of emotion called into play. 



Tracheae of Hexapods and of Spiders. — J. S. K. 

 (American Naturalist) considers the trachea; of these two 

 divisions of the arthropods not homologous ; since in the 

 one they are clearly modified appendages, whilst in the 

 other they occur on segments where well-marked 

 appendages exist. 



