112 



• KNOWLEDGE ♦ 



[Dec. 9, 1881. 



Ittttv^ to tf)c etiitor. 



[ n» EJilor dtie$ Hol hold himtrlf mpoiitiHt/or Uropiniont of hit rorretpondenlM, 

 Br cannol tindrrlakr to rrliir„ aonyirriplt or to rorrrtpoud iriV* Ikrir tcrilcrt. He 

 rtgntrit Utat all nmmitniealioiii thoald be OJ tkort lU pouMe, coniulentl) trilk /«« 

 and cUar tiatrmenU <iftha trriler'* mfittiinp.'] 



All EdUorial eommuxifaliont tlioulj U addreutd lo Iht Editor (^ KKOWLKDOB ; 

 •iH Biitintu KmiKunicaliani to the PublMeri, at the Office, 7*, Great Qii»n- 

 •Ireet, W.C. 



All Remillaitce; Chequei, and Foil-Office Orderi should be made payable to 

 Mnn-t. irymui. * Son.. 



•.'All Uttert to the Editor rill be y«t»herrd. For concenience of reference, 

 correepoudentt, ichm rejerrinf} to any letter, rill oblige b) mentionins itt uumier 

 and the page on irAicA it appeart. 



All Letter! or Qaeriet to the Editor irAiVA require attention in Ike current ume of 

 KxoWLBDOB,»A«u/</rMc* the Publithing Office not later than Ike Saturday preceding 

 Ike day tf publication. 



1 only 13 to be conlemnert and despised who is not in a 

 there anything more adverse to accuracy 



" In knowledge, that 



»t«te of transition N 



than tiiity of opinion." — Faraday. 



"There is no harm in making a mistake, but great harm in making none. Show 

 me a man who makea no mistakes, and 1 will show jou a man who has done 

 nothing," — Liebiy, ^__^_ 



#ur Co irrsiponti nut Columns. 



TO OUR READERS. 



[82] — Last week we had to add two leaves, incltiding three 

 pages of matter, to what we had intended to be our full weekly 

 supply for at least the first half-year, and, probably, for the first 

 year of our issue, and yet no less than 14 pp. of matter remained 

 over. Our readers will see, therefore, that we lie under a consi- 

 derable difficulty. We wish to find room for the better part of all 

 tlie correspondence which reaches us. But we cannot do so without 

 condensing most of the letters ; and even so, we run over the limits 

 which prudence dictates to us as suitable for a journal at the low 

 price wc liave adopted. On the other hand, we have much to 

 encourage us, even in the verj- circumstance which occasions our 

 difficulty. Before we reached our fiftli number we were receiving 

 more correspondence than we expected to receive after we had 

 been a year before the public; and the amount of this corre- 

 spondence really measures the kindness of the welcome extended 

 to us. That the friends we have already made are finding for 

 us a welcome elsewhere, we know by the rate at which our 

 circulation grows. We have had to reprint both our first 

 and second numbers (every line having to bo recomposed) ; 

 and the indications are, that large though the second edition of 

 No. 1 was, a third will before long be required. All this is very 

 gratifying, and it leads us to hope that, long before we had 

 expected, we shall be able to enlarge our weekly number. It may, 

 perhaps, be said, that there are journals larger than ours at the 

 same price, and that therefore we might at once enlarge our issue. 

 There may be such journals, but if there is one giving anything like 

 the same amount of original matter on scientijic subjects at the 

 same price, we have yet to hear of it. With the size we already 

 have, and the amount of original (and costly) matter we give our 

 readers, a very large sale is required to enable us permanently to 

 enlarge each number. We shall not wait till such a sale is attained, 

 but shall increase our weekly number in anticipation — probably 

 long before. Bat our readers will understand that their co-operation 

 is still needed. In the first place, each reader who contributes to 

 our correspondence columns is earnestly requested to limit his 

 remarks to subjects suitable to K.nowleuge, and to condense them 

 to the utmost of his power. Then, each who approves our 

 purpose can greatly help by making us known to others, noting to 

 them in turn that they also, if content with us, can help to extend 

 our sphere. We may point to the last four weeks' issue in evidence 

 that we arc anxious to meet our readers' wants by enlarging our 

 numbers— without, however, engaging that such enlargement shall 

 be permanent yet awhile. We may, indeed, note this, that if wc 

 had so kept down our correspondence and original matter as not to 

 exceed what was given in our first number, our present i.«sue, 

 though the growth of only five weeks, would be remunerative. We 

 have preferred, however, to increase our number, even at the risk 

 of loss, and wc ahall continue to follow that policy so long as we 



reccivo such oncouragemcul as heretofore from our readers an-l 

 correspondentH. 



Tilt: Kditor ANn I'boi'Kiktois oi " Knowledge." 



".I. I'. .'^." suggests that we sliould do as other papers dealing 

 H ith popular science have done, in having rr|>iirt8 of the meetings 

 of Hcienlitic societies. We would gladlv, if wi- could nllord the 

 s|)ace to do It properly. But let our friendly adviwr consider how 

 tiic matter stands. We already find it difficult to find spHCc for 

 what is ab.solutely essential as regards the purpose set before u«. 

 Now, the reports of scientific societies in the AthrnaiKm for Nov. 2*">, 

 which devotes only a section to science, and therefore condens*- 

 .such reports as much as possible, occupy a jiage and a third, which, 

 in the larger type of our correspondence columns, would be alniut 

 a page and three-quarters. Now, let us ask how the readers for 

 whom we specially cater, would care for so much space bcinf^ 

 occupied with reports like those in the Atliejittmii, excellent as 

 those reports are in their proper jilacc there. For instance, und< r 

 the head " Chemical Society," we find this. " The following papir- 

 were read: — 'Aluminium Alcohols, P.irt 11. Their Products •( 

 Decomposition by Heat,' by Messrs. J. H. Gladstone and A. Tribe,— 

 ' On the Chemical Action of Decomposing Vegetable Matter on thv 

 Rock-forming Sediment of the Carboniferous Period,' by Mr. E. 

 Wethered, — 'On a and /3 .\mylam,' by Mr. C. O'SnIIivan, — ' On the 

 Action of Oxides on Salts, Part IV. Potassic Chlorate and Ferric 

 Oxide,' by Messrs. E. J. Mills and G. Donald, — and ' On the Steejiin? 

 of Barley,' by Messrs. E. J. Mills and J. Pettigrew." 



Or take the following report of the Royal Society (Mr. W. Spotti-- 

 woode. President, in the chair) : — '" The following papers were re:i'! : 

 ' Preliminary Note on the Photographic Spectrum of Comet ' . 

 1881,' by Mr. W. Huggins, — ' Note on the Reversal of the Spcctmii 

 of Cyanogan,' V»y Profs. Livcing and Dewar, — 'The Sum of tl ■ 

 Series of the Reciprocals of the Prime Numbers and of tli''i' 

 Powers,' by Mr. C. W. Merrifield, — 'Further Note on the ilimri'- 

 Anatomy of the Thymus,' by Mr. H. Watney, — ' On the Production 

 of Transient Electric Currents in Iron and Steel Conductors,' 1. 

 Prof. Ewing, — 'Experimental Researches on the Propagation <■> 

 Heat by Conduction in Bone, Brain-tissue, and Skin,' by Dr. Lom- 

 bard, — 'On Allotropic or Active Nitrogen, and on the Compl' ■■ 

 Synthesis of Ammonia,' by Mr. G. S. Johnson, — 'On the Com- 

 parative Structure of the Brain in Rodents,' by Mr. W. B. Lew>. 

 — ' The Prchensores of Male Butterflies of the Genera Papilio ai.l 

 Ornithoptera,' by Mr. P. H. Gosse, — 'On the Propagation of Ir.- 

 hibitory Excitations in the Medulla Oblongata,' by Dr. U. Kr. - 

 necker and Mr. S. Meltzer, — ' Researches on Chemical Equivaleno .' 

 Parts IV. and V., by Mr. E. J. Mills,— and 'On the Refraction .1 

 Plane Polarised Light at the Surface of a Uniaxal CiTStal,' bv il r. 

 B. T. Glazebrook."" 



Or let us turn to a paper more especially devoted to science — 

 Nature. Here the reports, as might be expected, are fuller; buc 

 they would scarcely correspond with our si>ecial purposes. Here is 

 the report of the Entomological Society : — 



H. T. Stainton, F.R.S., President, in the chair. — Exhibitiotis : An 

 aberration of Vraptcrij.r eamlucaria, L., Mr. C. O. Waterhouse.— A 

 new species o! Anthcrda from the Gold Coast; and some micro- 

 scopic preparations of the saws, ic, of various humennptera, 

 prepared by Mr. P. Cameron of Glasgow, Mr. W. F. Kirby. — 

 Pieces of honeycomb constructed on a bare wall, without any 

 protection; and specimens and figures of new varities of Arma- 

 (Jillium vulyare, L., and PorceUio icahcr, Latr. Rev. A. E. Eaton. — 

 A specimen of Lijccena teams, Rett., var. Icarinus, Scriba, Dr. 

 U. G. Lang. — An undescribcd sjiccies of Cicadlda: from Borneo. 

 with unusually developed opcrcula, Mr. W. L. Distant. — A 

 female specimen of Dii/ourca iliiiiita, Lep., Mr. T. R. Billups. 

 — A specimen of Scleroderma domeftica, Westw. ; the lar\a w:ii 

 found parasitic on that of a Longicorn beetle in a ]iine-tree iit 

 Lyons; and some Diptcra which attack figs in Turkey and Egypt, 

 Sir S. S. Saunders (this led to an interesting discussion on tig- 

 parasites and caprification). — Some remarkable tubes formed by 

 Lepidopterous larva> at Aden ; and a specimen of t'criira rinula, L., 

 which it was thought at first might belong to t^. frniinca, Esp., the 

 President. — Papers road : Descriptions of new genera and species 

 of Ileterocerous Lepidoptcra from Japan (concluded), by Mr. A. G. 

 Butler ; and a memoir on the various Dipterous insects (Mufcid<v 

 and TipiiUda) destructive to cereals in Britain, by Professor 

 Westwood." 



The report of the Geological Society runs thus : — " H. Etheridge, 

 F.R.S., President, in the chair. The follow^ing communications were 

 read : — "On the genus Stoliczkaria, Dune, and its distinctness from 

 I'arkeria. Carji. and Brady,' by Prof. 1*. Martin Duncan, M.B. 

 Loud., F.R S., F.G.S., Pres. R.M.S. ' On the elasticity and strength- 

 constants of Japanese rocks,' by Thomas Gray, B.Sc, F.R.S.G., aixl 



