8 



NATURE 



[May 7, 1874 



Cercoleptes being characteristic. Hystricidse abound, 

 and Ruminants are very badly represented, only lamas, 

 peccaries, and tapirs being found. Sloths, armadillos, 

 and opossums are not found elsewhere, and there are 

 no frugivorous bats, Insectivores, Viverrida;, nor elephants. 

 The West India Islands form a well-marked (Antillean) 

 sub-region, possessing Solenodon, and peculiar Rodents. 



The Australian region, including Australia and the 

 Malay Archipelago up to Wallace's line {or .4 }i/ci>x/oga:a), 

 is characterised by the presence of the Monotremes and 

 Marsupials. Lastly New Zealand {Ornithogcra) has no 

 Mammals at all except two Bats. 



Mr. Sclater, in conclusion, explained the different 

 answers which had been given to the question : Why are 

 animals thus distributed ? showing that the Darwinian 

 hypothesis is a key to the whole subject, rendering quite 

 simple most of those difficulties which were previously 

 insurmountable. 



CAMPHOR 



THE camphor of commerce, it is well known, is the 

 produce of Cauiphora officinanim Nees., a tree of 

 China and Japan. To obtain it the wood is cut up into 

 pieces and boiled in water, when the camphor is de- 

 posited. It is afterwards purified by sublimation, and 

 further refined after its arrival in this country. Immense 

 quantities of this article are imported from Singapore, 

 and though so valuable in Kuropean commerce, in Suma- 

 tra and IJorneo a much higher value is put upon that 

 known as Sumatra camphor, which is obtained from 

 Dryobalanops aromatica Gaert. {D. caiiip/iora Coll.), which 

 does not come to this country as an article of trade. 

 Besides these there is a third kind of camphor, known in 

 China as Ngai camphor ; this, in point of value, stands 

 between the ordinary commerci.'xl article and the Malayan 

 or Sumatra camphor. Its b0tanic.1I source has for a long 

 time been doubtful, but it has generally been attributed to 

 an unknown species of ^-li tciitisia. Mr. D. Hanbury, 

 however, who has done so much in clearing up doubts on 

 the botany of many of our important articles of trade, 

 more especially in relation to drugs, has recently, in a 

 paper read before the Pharmaceutical Society, identified 

 the plant with Blinnca balsamifcra D.C. It is a tall, her- 

 baceous plant, and has long been known for the powerful 

 smell of camphor emitted from the leaves when bruised. 

 It is common in Assam and Burma, and indeed through- 

 out the Indian islands. 



The materials from which Mr. Hanbury has been en- 

 abled to solve the problem of the origin of this peculiar 

 camphor were sent him from Canton, and consisted of a 

 small branch of the plant, and specimens of the cam- 

 phor itself. These specimens, he says, " represented two 

 forms of the camphor — the one a perfectly colourless 

 crystalline substance, in flattish pieces as much as an 

 inch in length ;" the other, which was sent as crude cam- 

 phor, was a crystalline powder of a dirty white colour, 

 mixed with some fragments of vegetable tissue. " The 

 purer sample has an odour scarcely distinguishable from 

 that of ordinary camphor ; but the odour of the other is 

 perceptibly contaminated with a smell like that of worm- 

 wood." This camphor, though seldom seen in this coun- 

 try, was at one time attempted to be brought into com- 

 merce, one hundred pounds of it having been made in 

 Calcutta. It is used in the East, both m medicine and 

 in the manufacture of the scented Chinese inks. It is 

 stated that " about 15,000 dols.' (3,000/.) worth is annually 

 exported from Canton to Shanghai and Ningpo, whence 

 it finds its way to the ink-factories of Wei-chau and other 

 places." 



Though it is now proved that B. Imlsa mi/era is the 

 plant yielding the bulk of Ngai camphor, it is not im- 

 probable that some other plants lend their aid, for the 

 term " Ngai " is, it appears, applied to several belonging 

 to the Labiatas and Composite. John R. Jackson 



THE "SPAR CA VES" OF THE NORTH BRIDGE, 

 EDINBURGH 



THE North Bridge, which spans the deep valley lying 

 between the Old and New Towns of Edinburgh, 

 was built upwards of a hundred years ago, and its huge 

 arches must be familiar to all who have entered Edin- 

 burgh from the south by railway, the terminus for the 

 main southern lines being situated just below. Between 

 the arches of the bridge and the roadway above are a num- 

 ber of chambers or vaults which have not been opened, till 

 recently, since the bridge was built. In carrying out the 

 operations necessary forthe widening of the now too narrow 

 bridge, these vaulted chambers have been opened up, and 

 one of them has been visited by Prof Geikie, who, in a 

 communication to the ScDlsinnii, describes the wonderful 

 sights he saw. 



" The chamber we examined," he says, " was about 

 eight or ten feet broad, and varied in height according to 

 the rise and fall of the floor over the arch underneath, the 

 floor coming sometimes so near the roof that we needed 

 to stoop low to get through. From the vaulted ceiling, 

 and especially from the joints of the masonry, hung 

 hundreds of ' stalactites '—delicate spar icicles of snowy 

 whiteness. In many cases they reached to the floor, 

 forming slender thread-like pillars. In making our way 

 we were under the necessity of brushing down many of 

 these pendant masses. Now and then we seemed to be 

 marching through a grove of white and brittle canes. 

 The longest entire one we could see measured rather 

 more than six feet in length. Usually they were slim 

 stalks somewhat like thick and not very well-made 

 tobacco-pipes, but towards the sides of the vaults they 

 became thicker and stronger, one which we carried off 

 measuring about four feet in length, and as stout as an 

 ordinary walking-stick. The same material as that 

 forming the stalactites spread in ribbed sheets down the 

 j sides of the vault. The floor, too, was dotted all over with 

 little monticules of the same snow-white crystalline spar. 

 " A more illustrative example of a stalactitic cavern 

 I could not be found. The whole process was laid, open 

 i before us in all its stages. Along the joints of the 

 masonry overhead could be seen here and there a drop 

 of clear water ready to fall. At other places the drop 

 hung by the end of a tiny white stone icicle, to which it 

 was adding its own minute contribution as it evaporated. 

 From the mere rudimentary stumps the stalactites could 

 be traced of all lengths until they were found firmly 

 united to the spar hillocks on the floor. Every one of 

 these hillocks, too, lay directly beneath the drip, catching 

 the remainder of the stone dissolved in the dropping and 

 evaporating water. In every case the stalactites were 

 tubes ; even the thickest of them, though it had under- 

 gone great changes from deposit on its outer surface, re- 

 tained, nevertheless, its bore. Usually there hung a clear 

 water-drop from the end of the stalk, ready to descend 

 upon its white stony mound beneath. 



'■.So fir, except for the undisturbed perfection of the 

 whole, there was nothmg which may not be seen under 

 many an old vault. But what astonished me most was 

 the evidence of a continuous growth and destruction of 

 these slim stalks of stone during an actually known 

 period. In a great many cases the little 'stalagmite' 

 mounds were each surmounted by a short slender stalk, 

 as the Calton Hill is by Nelson's monument. There 

 could be no doubt that these monumental-looking 

 objects were merely the lower ends of once-con- 

 tinuous stalactite pillars. And indeed, searching 

 round the mound I could usually find fragments of 

 the broken column imbedded in the growing stalag- 

 mite. What had broken them .' Perhaps a heavy 

 omnibus thundering overhead, or a laden lorry or a 

 deftly-fired royal salute. Anyhow, for a hundred years 



