HARDWICKE'S SCIENCE-GOSSIP. 



117 



caterpillars are produced very early in the spring, a 

 late and inclement season may destroy their food- 

 plant and themselves ; in which case the reserve 

 of pupae would prevent the total destruction of the 

 species. I should like to ask a question in return : 

 Sometimes a large cocoon is formed, which contains 

 two pupae, I have never had any insects emerge 

 from these double cocoons. Is this usual? and 

 w l,y ? — jj m jfr Livett, M.D., Wells, Somersetshire. 



Popular Errors. — Is not _ E. T. Cox mis- 

 taken in supposing the verse in the Psalms, to 

 which he refers, speaks of the adder as being deaf. 

 Why then should she stop her ears ? Does it not 

 rather refer to what seems a common opinion, and 

 what the natives in some parts practise, — that 

 serpents of some kinds are charmed, or rendered 

 quiet by music ? And so the Psalmist speaks of 

 some who would not listen to advice, and who re- 

 sembled a serpent whom the most appropriate 

 music could not charm. Query— are serpents deaf? 

 —E. T. S. 



Jet.— In the number of Science-Gossip for this 

 month is a paper by Mr. Taylor on jet, in which he 

 speaks of it as a " pitch or gum," and as " lumps of 

 resin" exuding from the trees. Surely this is 

 hardly a right description. It will cut neither as a 

 gum nor resin in the way of dissolving in any liquid ; 

 and on making sections of it, the grain of fir-wood 

 is shown beautifully ; as are also the glands pos- 

 sessed by fir-wood. So that I conclude some of it, 

 if not all, must have been wood. Further informa- 

 tion as to its being a pitch or resin will oblige 

 E. T. S. 



Willow Leaves for Yeast. — A correspondent 

 of the Journal of Agriculture states that the leaves 

 of the common Basket-willow {Salix nigra, Mar- 

 shall) make an excellent yeast, if treated in the 

 same way as is usual with hops. " The discovery," 

 he says, "was made in my family last summer, and 

 after a thorough trial I was convinced that there is 

 nothing equal to it, as it _ rises much quicker than 

 hops — in half the time, — imparts none of that hop 

 flavour so disagreeable to some, and in fact makes 

 better bread in every way. The thing is well worthy 

 the attention of every good housewife; and lest 

 some should hesitate inconsequence of not knowing 

 the medical properties of the willow in question, I 

 will add that it is a healthful tonic, from which no 

 harm can possibly arise." 



Cleaning Coral— If "W. H. M." would boil 

 the coral in milk, I think he would succeed to his 

 satisfaction. I have repeatedly done so with pieces 

 which I have had for years, and find they look as well 

 as when new. — John M. Campbell. 



Correction of Lenses. — Myself and several of 

 my friends have immersion lenses of Gundlach's, 

 but none of us know how to use the correcting ad- 

 justment. I wrote some time ago to Mr. Baker, 

 the agent, to inquire, but he could give me no 

 specific directions. Could you or any of your 

 readers inform me of the correct way, or the best, 

 to bring out the performance of the glasses?—^. D. 

 Knight. 



Botanical Exchange Club (p. 96).— "W.W. S." 

 The Editor of Science-Gossip is supposed to be 

 omniscient. There is a Botanical Exchange Club, 

 and a very good thing too. Curator, Dr. J. Bos- 

 well-Syme ; Secretaries, Mr. Baker and Dr. Trimen, 



either of whom will give " W. W. S." all needful 

 information. — A Member of B. E. C. 



Borax and Cockroaches. — It may not be 

 generally known how very valuable borax is in 

 various purposes of household use. It is the very 

 best cockroach-exterminator yet discovered. One 

 half-pound has completely cleared a large house, 

 formerly swarming with them, so that the appear- 

 ance of one in a month is quite a novelty. The 

 various exterminating powders puffed and adver- 

 tised have been found not fully effective, tending 

 rather to stupefy the cockroaches than to kill them. 

 There is something peculiar, either in the smell or 

 touch of borax, which is certain death to them. 

 They will flee in terror from it, and never appear 

 again where it has once been placed. It is also a 

 great advantage that borax is perfectly harmless to 

 human beings ; hence no danger from poisoning. — 

 Journal of Applied Science. 



The Pineapple.— The date of the introduction 

 of the Pineapple to this country should be placed, 

 I think, at least a century earlier than that assigned 

 to it by the author of the"Eruits of Great Britain," 

 quoted in the April number of Science-Gossip ; 

 for this reason, that in 1575 a worthy gentleman, 

 whom (for more or less sufficient reasons) I am 

 pleased to consider an ancestor of mine, assumed 

 with the authority of the Heralds' College, a coat of 

 arms, with chevron and birds blue, and all the rest 

 of it, with a crest, "a raven's head couped vert, 

 wings displayed," &c., and " in the beak a slip of two 

 pineapples gules." The excellent knight who re- 

 ceived all this honour resided at Christ Church, 

 Hampshire, and it may be permitted to suppose 

 that he was one of those who, in that age of enter- 

 prise, distinguished themselves by roaming the 

 world in search of wonders, as gallant mariners, or 

 as buccaneers; and that to him belongs the merit, 

 if not the fame, of the first bringing to this country 

 of this most luscious of tropical fruits. There is 

 one difficulty, however, in this, and on the very 

 face of it (as you will see by the enclosed stamp), 

 that the mode of growth seems to have been quite 

 misunderstood, for the fruit is drawn as though it 

 were gathered from a tree bearing some British 

 pippin. Yet, perhaps, even this mistake (which I 

 hope is due to the draughtsman at the Heralds' 

 College) may help to explain why the name of apple 

 was given to a fruit in form, in flavour, and in 

 growth, so utterly dissimilar. Respect for the 

 Chancellor of the Exchequer prevents my signing 

 myself more fully than— M. Q. M. C. 



Sounding Lead (vol. vi. p. 189). — Under this 

 heading " C. L. J." asks for a description of some 

 sort of plummet, or small drag, which will bring 

 up specimens of diatoms, foraminifera, &c, from 

 considerable depths of water, without the use of 

 tallow. I think 1 can suggest a kind of plummet 

 which may be found useful, though I have never 

 tried it. My plan is this : — Cast a leaden plummet 

 of an obovate, or inverted pear-shape, adding a ring 

 large enough to have a strong cord attached to it. 

 Near the point bore two or three holes in a down- 

 ward direction, so as to form as many cells in the 

 lower part of the plummet, or the holes might be 

 bored until they meet, and form a large cavity. 

 If this plummet be dropped, and the line allowed 

 to run out rapidly, the point will sink in the sand 

 or mud, and on hauling it up the cavities will be 

 found to be full— A. H. A. 



