234 



HARDVVICKE'S SCIENCE-GOSSIP. 



to their normal appearance. I do, however, say, 

 that wherever there is basaltic lava, there was pre- 

 viously sedimentary basalt. I also say that sedi- 

 mentary basalt exists in its normal condition ! I do 

 not intend to be dogmatic. If any one can show 

 that basalt cannot be sedimentary, I will accept the 

 proof.— JST. -P. Malet. 



A Difficulty.— I should be glad if some of your 

 correspondents could enlighten me in a difficulty. 

 On the hills near Caterham junction, and in the 

 whole of that neighbourhood, the juniper grows in 

 great abundance, but it is always a little low bushy 

 shrub. But a few miles further, near Mickleham, 

 Boxhill, and thereabouts, the shrub is exceedingly 

 common, but it invariably reaches a considerable 

 height, say from 10 to 15 feet. I should be glad 

 to know if the smaller kind is the J. nana, and 

 the larger the /. communis? There is as much 

 difference in the general appearance of the shrub in 

 these two different localities as between the TJlex 

 europceus and the If. nana; and I have found it very 

 difficult to find any permanent difference between 

 these two plants except in the manner of growth. 

 Both Smith, Hooker, and Withering say the J. nana 

 is only found on high mountains, which makes me 

 doubtful as to the smaller being it ; at the same time 

 the soil is chalk in both the localities 1 name, and 

 therefore there seems no reason why it should be 

 found of such different sizes within so short a dis- 

 tance. — H. E. Wilkinson, Anerley, S.E. 



Swallows.— In reply to " M. A. W." in Science- 

 Gossip, p. 190, 1 may say that 1 have noticed three 

 swallows on several occasions attending one nest. 

 I have not observed three birds to a nest, in any 

 species but the Swallow and the Starling. The sub- 

 ject is well worthy of investgiation. I have seen no 

 explanation in books. Is the odd bird a young one 

 ofi the previous year, an additional female linked 

 with the male, or an occasional visitor, and does the 

 extra bird remain to the end of the breeding season ? 

 — Geo. Roberts. 



The Irish Arran.— In Science-Gossip, Aug. 1st, 

 the writer of " Holiday Rambles " inquires playfully 

 if there is not a "Rock" somewhere in Galway 

 Bay of the name of Arran. The " Rock " in Galway 

 Bay is rather a respectable one. It covers an area 

 of 11,287 acres, and affords occupation and a means 

 of subsistence to over 3,000 people, tr at least it 

 did a few years ago. On this " rock" too, in olden 

 times, the good seed was sown and took fruitful root, 

 for over twenty churches once consecrated its soil. 

 It consists of a group of small islands, one of which, 

 Arranmore or lnishmore, the Island of the Saints, 

 still invites devotees as well as tourists to visit 

 its sacred shades. There can be little doubt that 

 your correspondent sought his Jjuga pyramidalis 

 and Helianthemum canum in the wrong Arran, as 

 he himself suspects ; for Hooker names W. Ireland, 

 Arran Isles, as the habitat of both plants, not Arran, 

 county of Bute. Perhaps, then, if the pleasant 

 writer of " Holiday Rambles " will bend his steps, 

 when next he makes a holiday ramble, to the 

 " rock" in Galway Bay, he may meet with his quest, 

 and see much worth seeing besides. — Isabella H. 

 Knox, Belfast. 



Livingstone's Sponge. — In Livingstone's "Last 

 Journals" frequent mention is made of sponge that 

 was found in the streams through which the sick 

 man had to wade. This sponge extended from the 

 banks and made the fording very difficult. In vol. i. 



p. 113, it is described as " a bog or sponge, a peaty 

 loam floating on sand." At pp. 321-5, these sponges 

 "consist of a black, porous earth, covered with 

 a hard wiry grass," and " streams of oxide as thick 



as treacle move along in the sponge like red 



glaciers." In this sponge the water is always " cir- 

 culating and oozing." What is this sponge ? In 

 some of our chalk springs we have little fibres 

 attached to the water orifice, like small brown roots. 

 They are not roots, but little threads of earthy 

 matter, soft and friable, held together by a shining 

 silicious coat. I have accounted for these fibres by 

 the silicious matter in the chalk covering and hold- 

 ing together earthy matter issuing with it ; but, 

 says Livingstone, p. 213, vol. ii., " Flint does not 

 exist in any part south of the equator." If that 

 which we commonly call flint does not exist, we 

 know that varied forms of silex exist in the South- 

 African diamond fields ; and at p. 325, vol. i., 

 Livingstone writes, " the water descending about, 

 8 ft., comes to a stratum of yellow sand, beneath 

 which there is a stratum of fine white sand." This 

 sand must be formed from broken-up silicious rocks, 

 so that in our own water-springs we may find a 

 resemblance to the sponge in the brooks on the 

 great plateau of Central Africa, from whence come 

 (p, 327) "the secondary sources of Zambesi, Congo, 

 and the Nile." In our spring-heads the fibres are 

 short; where there is nothing to adhere to, the 

 liquid silex goes on with the water. In Africa 

 there is more material to be clothed than there is 

 clothing for it ; hence, the red oxide moves along in 

 defined streams through the fields of sponge. 

 Sponge is not a proper term for this substance. 

 Can you, Sir, or your readers, help me to a correct 

 one ? Of course, the fibre in our own springs has 

 a name, but in the absence of reference-books I do 

 not recollect it. As hair when collected into masses 

 forms horns and hoofs, as silicious matter when col- 

 lected from springs grows into sinter; so these 

 fibres are related to the sinter, and may be called 

 the beard of the water-spring, if there is no name 

 already given to them.— B. P. Malet. 



Colours of Canaries. — In connection with 

 W. T. Greene's query as to Cayenne pepper, noticed 

 in Answers to Correspondents (August No.), allow 

 me to state that Norwich canary- breeders use it to 

 change the colour of their birds. Their feathers 

 after moulting come of a deep orange-colour, but 

 their breeding powers are interfered with. Pounds 

 of cayenne are sold annually for this purpose. — 

 IF. G. P. 



Laburnum Flowers— The purple and yellow 

 flowers sent to " L. A. B." are in all probability the 

 result of grafting. The first purple laburnum was 

 produced in Paris. It was a hybrid between the 

 Swiss Cytisus and the C. purpureus, a native of 

 Carniola. The branches below the graft generally 

 produce yellow flowers and those above purple ; but 

 it is not very uncommon to find both coloured 

 blossoms on the same cluster.— Helen E. Watney. 



Late Flowering Laburnum— On my way up 

 to town one morning in the last week of August I 

 noticed a laburnum-tree coming fully into flower. 

 The branches were covered with blossom, also 

 makiug new wood. Is not this very unusual ?— 

 /. IF. G. 



Cottage Pharmacy. — A prize offered at a 

 cottage-garden show in this neighbourhood "for 

 the best collection of herbs used for physic, poul- 



