106 



♦ KNOWLEDGE 



[Feb. 16, 1883. 



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" Let Knowledge grow from more to more." — Alxued Tennyson. 



ilfttriE! to tl)r eiJitor. 



Only a small proportion of Letters received can possibly be in- 

 serted. Correspondents must not be offended, therefore, should their 

 letters not appear. 



All Editorial communications should be addressed to the Editor of 

 Knowledge ; all Business commmiications to the Publishers, at the 

 Office, 74, Great Queen-street, W.C. If this is not attended to, 



DELAYS arise FOR WHICH THE EDITOR IS NOT RESPONSIBLE. 



All Remittances, Cheques, and Post Office Orders should be made 

 payable to Messrs. Wyman & Sons. 



The Editor is not responsible for the opinions of correspondents. 



'So COMMUNICATIONS ARE ANSWERED BY POST, EVEN THOUGH STAMPED 

 AND DIRECTED ENVELOPE BE ENCLOSED. 



EDELWEISS. 

 [720]— In answer to " Corkonian's " letter (713), I think he will 

 find that the scientific name for Edelweiss is : — " Gnaphalium 

 leontopodium," and that Linna;us put it into Class 19, or. 2, Nat. or. 

 Compositse. Hermit. 



[721] — The Americans have prophesied a disastrous storm and 

 tidal wave for March 11 (two days after the new moon), when 

 every ship at sea will be submerged and great damage be done on 

 land. 



Have our scientific people in England calculated that there will 

 be any veiy abnormal tide about that time P If so, what will be 

 the difference in time between its occui-rence here and its occur- 

 rence in America ? M. M. 



[The prophecy is bosh. — R. P.] 



GORSE AND BROOM. 



[722] — I have been much struck with the beauty and instruc- 

 tiveuess of Mr. Grant Allen's papers, "A Naturalist's Year." 



Might I, through your kindness, ask his attention to two facts in 

 reference to his fifth article, " Gorse Blossoms" P 1. The broom is 

 hardly less successful in protecting its blossom than the gorse, at 

 least not so in these Highlands. Both plants are, to tho animals 

 that browse upon them, for winter use. While the grass is green 

 and the heather juicy, neither sheep nor deer will touch either 

 broom or gorse ; but when the heather gets hard and the grass 

 withered, these animals look for subsistence to the juicy broom 

 and the flowering furze. These plants defend their lives in 

 different ways. The juice of the broom has something of a narcotic 

 quality in it. At least, shepherds say that it makes their sheep sick 

 or drunk. This is a well-known fact among shepherds; and it is 

 certain that deer very soon get tired of it. This is the broom's 

 self-defence, not for the seeds of that, but of tho following season. 



The gorse, on the other hand, is armed with its formidable 

 prickles ; but these do not so effectually protect it as tho nature 

 of its juice does the broom. Flocks of sheep and herds of deer rush 

 to wastes covered with furze while the broom is scarcely touched. 

 Hence it is that in deer forests evei-y means is taken to propagate 

 the gorse while the broom is left to take care of itself, and does it 

 very effectually. 



Second, there is an old saying, I don't know whether English or 

 Scotch— perhaps both— to the effect : "Pluck broom hae broom; cut 

 furze hae furze." It is dithcult to pluck broom by the roots, hence 

 its safety. It ia easy to cut furze — all animals browsing upon it are 

 doing so, hence its safety. J. G. M. 



DARK SUNS. 



[723]— Clifford says (Furlnicihlly Revieii; June, 1875):— "A 

 great amount of light must be stopped by the dark bodies of 

 burnt-out suns." Is this accurately put ? — or rather, is there 

 justifiableness ? Faciebat. 



[A great amount absolutely, but a very small amount relatively 

 — most probably. — R. P.] 



A DISINFECTANT. 

 [721] — A much cheaper disinfectant than that mentioned by Mr. 

 JIattieu Williams at page 47, Vol. III., of Knowledge, is the chloride 

 of lead. This is very simply made by dissolving half a dram of lead 

 nitrate in a pint of boiling water. This is to be put, with two drama 

 of common salt, into a pail, wliich must be filled with rain water, in 

 the meantime stirring until all the salt is dissolved. The cost of 

 load nitrate is Sd. per lb., common salt Id. per lb. This will make 

 250 pails of disinfecting fluid at a cost of lOd., or at the rate of 

 very nearly thirteen for one halfpenny. 



F. W. Cory, M.R.C.S. Eng., Ac. 



A PUZZLE. 

 [725] — A correspondent sends a solution of the following: — 

 Twenty-one girls to go out three and three on ten days, no two being 

 together more than once. A demonstration of the method by 

 which the solution is obtained is promised. If not too long, I hope 

 to be able to give both the solution and the demonstration. — K. P. 



BRAIN TROUBLES. 

 [726] — I was away from my books at the time when som. 

 interesting letters appeared in your valuable paper on the above. 

 I knew that Dr. Forbes Winslow had written a book on this 

 subject, entitled, " On Obscure Diseases of the Brain," and his notes 

 may be of value to the writers of the above letters. Such cases 

 as they describe, the doctor calls " incipient symptoms of cerebral 

 disease," and he advises the patients to put themselves under 

 proper treatment. He quotes cases similar to those mentioned. 

 For instance, one patient used to transform "flute" into " tufle," 

 "gum" into "mug," &c.; another forgot names; another the first 

 syllables of words. One curious case is worth mentioning : Mr. 



Von B , envoy to Madrid, a man of a serious turn of mind, yet 



by no means hypochondraical, went out one morning to pay visits. 

 At one house he had to give in his name, " but this he luid at that 

 time entirely forgotten." Turning to a friend, he exclaimed, " For 

 God's sake, tell me who I am." The doctor says that no change 

 may be noticed in mental powers, either by the patient or his 

 friends, but " the change may have progressed insidiously and 

 steadily, having slowly and almost imperceptibly induced important 

 molecular modifications in the delicate vesicular neurine of the 

 brain, ultimately resulting iu some aberration of ideas or other 



I hope you will be able to find space for this note, as it may be of 

 value to some of your correspondents. I would advise them to read 

 the book ; it is extremely interesting. PsYCHOMANTIS. 



[The correspondence about Braiu Troubles arose out of my 

 articles on that subject, republished in " Nature Studies." There 

 is much reference there to Dr. Forbes Winslow's book, but I am 

 rather careful to advise those who have slight brain troiibles to 

 avoid unnecessary anxiety. I have known cases where mischief has 

 arisen from the nervous fear lest some mental trick should mean 

 approaching cerebral disease. Inmost cases, change of employment, 

 relaxation, light exercise, and so forth, will set all right. — R. P.] 



LETTERS RECEIVED. 



Begulcs. — Fred. Lobintz. — J. H. Bridger. — Curate (" The 

 Stars in their Seasons"). — G. Cl.\verixg Mesnard (same book 

 enlarged, and with more illustrations). — G. Hooper. — W. P. You 

 misunderstand us both. — F. M. Sutcliffe. Rccueil Chnisi excellent. 

 — A Cockney. — Euith Dalton. — E. C. Hooton. — Peccavi.- — E. D. G. 

 Suggestion, " redde " for " read " past, good. Opinions about logic 

 less useful than facts or reasoning. How much better a letter 

 than anonymous note on post-card. — Trisectus. Bisectus, if your 

 trisection valid. — Undergraduate. Clifford in error, G. Darwin 

 right. — H. M. Parkhurst. First sj-Uogism impossible: hence in- 

 credible result. — Excelsior. Thanks, — H. L. — R. Morham. — W. W. 

 — Jas. Graham. Powerless. — T. W. " The Naturalist's Year " will 

 probably be republished. Mr. Allen retains all such rights. — E. J. 

 Castle. Problem has often been reduced to that degree. — J. E. 

 Earing. — German. — W. Buchanan. — W. H. W. M. Canaden.sis. — 

 Peccavi. — Young A.stronomer. — W. H. Brown. — J. Boots. — R. B. 

 Blackmore. — Rev. M. Allan.son. — J. J. Robertson. — Mat. Duffy. 

 — Prawns. — Lieut. Binnie. — The Elms. — An Admiring Student. 

 — Samson Harlowe. — Tourniquet (what a dreadful story!). — 

 N. L. L.- — A Publican. 



Erratum. — In Admiral Sullivan's letter on " Transit of Venus," 

 in last week's Knowledge, p. 90, at fifth line below the engraving, 

 read " brightest colour being near the planet." The words italicised 

 were accidentally omitted. 



