Dec. 9, 1881.] 



KNO^A^LEDGE 



123 



( ruplty has not beer, observed, glnttony lias been the marked fail npr. 

 1 have seen a chinless man eat like a pis;, and look exactly like a 

 pii; while eating'. Does not the paucity of this characteristically- 

 iniman feature point to the animal propensities being in excess of 

 the moral, if not the intellectual, tendencies ? The Papuans are 

 said to ha%-o little chin, and to be very cruel. Ethnologist. 



rsi] — TnE Jfoox's At-MOsphere. — By whom and when was the 

 iliscovery made that there is no atmosphere around the moon ? 

 Swidenborg claims the honour of having the fact communicated to 



in by angels, and that he was the first to know and publish it. 

 "^2j — Probabilities. — Has not the writer of the article on 



1 rusting to Luck " put " eight times running " and " nine times 

 running" where he should have written "nine times running" and 

 ■ tpu times running " respectively, the chances being 



— and — equal to and 



2» 2'" ' 512 102 1 



1 -liectivcly?— H. A. N.— [Yes.— Ed.] 



S3] — Chemical Qveries. — (a) Arc there more than three allo- 

 ipic modiScations of sulphur? The two crystalline forms and 

 ■ plastic modification I am acquainted with, but in Miller's " In- 

 ' p.'anic Chemistry " (" Longman's Text-Books"), 187-1-, it is stated 

 t hat " a fourth may be procured by placing in carbon disuli)hide 

 tlie hard mass furnished by keeping the viscous sulphur till it 

 ■umes solid. The carbon disulphide discloses all that can be 

 noved from the mass, and a gre[i amorpltoua powder is left" 

 142). Roscoe, in his "Elementary Chemistry," simply says 

 '! '■ the tenacious " (i.e., viscous) " form is insoluble in " carbon 

 ilphide. Does the latter refer to the amorphous powder men- 

 nod by Miller? (6) In Roscoe's "Elementary Chemistry," 

 i'. t>2. edit. 1880, referring to nitrogen tetroxide, 1 find it stated 

 that " this substance forms the greater part of the reddish brown 

 fiimos evolved when nitrous oxide gas escapes into the air." Should 

 •' :s not not be nitric ? (I may s.iy that at present I have not an 

 1 ortnnity of trjiug these for myself.) — TllEION'. 

 St] — Ancient Man. — In Darwin's " Origin of Species," I read, 

 -Mr. Uorner's researches have rendered it in some degree probable 

 tl.at man eutficiontly civilised to have manufactured pottery existed 

 in ilie valley of the Nile thirteen or fourteen thousand years ago." 

 I -1 inll like some information about these researches, and their 

 r, ii ,l,i:,iy.— Clio. 



, sj -A Gkavity Illusion. — The Toricelli tube, or a long glass 

 tulio filled with mercury, and turned upside down, when full, into a 

 mil of mercury again, is said by some acquaintance of mine to be 

 unexplained, in so far that in theory, he says, the mercury glass- 

 tube, when lifted up, should not weigh more than the weight of the 

 (.'la.us, considering that the mercury is carried by the cup on the 

 uible in which it is. But, instead of this, it is found to weigh very 

 much more. I was not many minutes in solving the mystery to 

 myself, but do not yet know if it is really a mystery to professors of 

 I riysics, OS my acquaint.ance maintains. I can hardly tliink so, as I 

 tanov to have read the law that gives the cause. Uowever, I vnU 

 ■_"vo my version of it, after seme one of yonr readers answers. — 

 K J". D. " Seibst." [There is no mystery in the matter, but the study 

 of this question, as of others in our Query columns, may be a useful 

 exercise to beginners in physics. — Ed.] 



[86] — The CoLorR of Birds' Eggs. — Are the different markings 

 on birds' eggs considered to be merely accidental, or designed for 

 special purposes ? — Araohnida. 



[87] — ToADs.^What is the internal construction of the common 

 toad, which permits of its existing for many years enclosed in blocks 

 of solid matter ? — AR.\cnNiDA. 



[88] — Brain Injuries. — How is it the brain can be cut and 

 cauterised without exciting sensation ? If true, this contradicts, 

 apparently, the statement that the brain is the organ of feeling, 

 made in W. L.'e letter (29, Xo. 3). Is electricity necessary to 

 convey the least feeling or irritation to the brain ? — Bee. 



[89] — Gelatine Plates. — I have just now a few gelatine plates, 

 in which a red streak appears, either on the top or at the bottom, 

 and seems to eat its way through the film, and so spoils them ; also 

 the silver from the paper coming on to the plate. A remedy for 

 the above would oblige. Have any photographic readers of Know- 

 ledge tried to develope their gelatine plates by flowing over them a 

 weak solotion of silver, and developing afterwards the same as a 

 wet plate ? If so, kindly give me their experiences. — Pebskvere. 



[90] — The Magnetic Needle. — I should be glad if any reader 

 can give me any information why the needle of the compa.ss always 

 poin's to the north, what is the attraction, .ic. — W. H. Pertwee. 



[91] — Missing Link. — Knowledge for Nov. 25, p. 71, has anai'ticle, 



"The Missing Link," in which it refers to an article that has ap- 



■ pcared on the same subject in a recent volume of the Gentleman's 



Mag<i2i)ie. Please say name of month in which this appeared. — 



Teastlant. 



Jxtplirs to C^ufrtfS. 



[1] — The E.arth's Inclination. — The motion of the earth is best 

 shown by suspending a small globe by a piece of string, and carrying 

 it round a candle (the candle being in the centre of its path). If 

 the globe is carried on a level with the caudle, it is seen that the 

 poles will both just see the candle, i.e., tho poles and the whole 

 earth will have perpetual spring. The true motion will be obtained 

 by making the circular path dip half below and half above tho level 

 of the candle as it is carried round, so that at the lowest part the 

 whole of the North Arctic zone may be in light, and at its highest 

 point in shadow. — H. A. N. 



[8] — A'oLustE OF Sphere. — Given that area of sphere = area o 

 J great circles = -Itt)^. Let the sphere be divided into pyramids, 

 with the apex at the centre. If the number of pyramids is great, 

 the base of each is nearly plane, and the pyramid 

 "l 

 =; X height X base 



1 



=^ X rx base. 



The whole sphere is one of these pyramids multiplied by tho 

 number of times the area of the sphere contains the base, i.e., 



1 ■STrr' l 



5i-(base') X ; =^irr' 



3 "■ • base 3 



= ^ of cylinder. 



This implies, however, the knowledge that the area = four great 

 circles, which cannot be proved without the calculus. — H. A. N. 



[10] — The Zoetrope. — The isipression of any sight remains on 

 the retina for the seventh part of a second ; if a new impression is 

 received before the first has faded, the two are seen simultaneously, 

 and if the Zoetrope is turned too quickly, tho images run into one 

 another. If it is turned so that one-seventh of a second intervenes 

 between two impressions, the motion will appear continuous ; if it 

 moves slower than this, it will seem jerky. — H. A. N. 



[14] — Velocity of Sound. — "Sound's" difficulty arises, I think, 

 from his not considering that the air is sensibly devoid of absorp- 

 tion and radiation, so that the heat generated in tho condensation 

 remains there to augment the velocity — or, rather, the elasticity upon 

 which the velocity depends. In the rarefaction, tho elasticity is 

 lowered, both by the separation of the particles and the cold de- 

 veloped by such separation ; and consequently " the cold developed 

 augments the difference of elastic force upon which the propagation 

 of the rarefaction depends." It is because the heat generated in 

 the condensation augments the rapidity of the condensation, and the 

 cold developed augments the rapidity of the rarefaction, that tho 

 heat and cold both help to augment the velocity of the sound wave. 

 In gases possessing considerable absorptive and radiative power, 

 " Sound's " objection would be perfectly valid. — T. J. H. 



[16] — German and English. — In reply to " Eclecticus," Messrs. 

 Macmillan & Co. publish a work which I think would suit him. 

 entitled " A Comparative Grammar of the Teutonic Languages." 

 By G. Helfenstein. Its price, I believe, is ISs.— W. G. Uoi.fk. 



[18] — Chemical Treatises. — I have before me the ninth edition 

 of " Fownes' Chemi.stry," on the old or equivalent notation, with an 

 appendix epitome of tlie new system. Then 1 havo Hoffmans' 

 work on " Modem Chemistry ; " also the little volume by Wurtz, 

 " Chemical Philosophy according to Modern Theories," translated 

 byCrookes; also "The New Chemistry," by Cooke (International 

 Series) ; and, lastly, " Pilden's Chemical Philosophy." I would 

 especially award the prize to the little work of Wurtz, which is 

 exceedingly good and clever ; but many years' study convinces mo 

 that "Modern Chemistry" is wholly based on very slender hypo- 

 theses, and that the consequent complexity and confusion must 

 necessitate a change. An independent inquirer has little chance in 

 England, but in France the Chemical Hierarchy is untainted with 

 inconsiderate revolution; and M. Berthelot must bo considered one 

 of the greatest chemists of the age. If old or equivalent chemistry 

 means knou'led<je, and new chemistry means hypothesis, it is 

 especially a propos for this Paper to ventilate and make clear the 

 difference. — Eclecticus. 



[igi — CoMp.iRATivE Anatomy of Birds and Mammals.— The 

 furcula of birds are formed by the nnioH of two bones called the 

 clavicles. These arc almost entirely absent in mammals. \Vhen 

 present they are very rudimentary, and usually unoseified ; so that 

 no trace of them is found in the dried skeleton. In man, the 

 clavicles are more developed than in the other mammals, and con- 

 stitute the so-called collar-bones. They are very rudimentary in 

 dogs and rabbits. In the felida) (lions, tigers, cats, &c.) they are 

 more developed than in other camivora, but have no particular 



