80 



♦ KNOWLEDGE ♦ 



[Nov. 25, 1881. 



©ufric£(. 



[10]— CoMP.VK.VTIVE .V.NATOMV OK BiKDS .VXD AXIM,\LS.— Can J'OU 



kindly tell me ihriiiiKli your paper the eorrcaponiling bones in man 

 imd other mnmmnU to the furcula of birds ? I have consulted all the 

 hooka to my linnd, and cannot find out. Wishing all success to 

 your interesting paper.— Ciiables Siiebdobx. 



[20] — OiMiEBY. — Can you or any of your readers kindly inform 

 mo where an Orrery can bo seen ? — Vi'Uax. 



[21] — Dkbp-Ska SorxniNos. — Could you tell me where I can find 

 an Bcconnt of " Deep-Sea Soundings " taken off tho coast of New 

 CJuinca?— .Stanhoi-e T. Speer. 



[22] — FuMAi.HAfT.— Is this visible in England at about 9 p.m. ? 

 My little daughter having deciilcd, by a study of your star maps, 

 in the aflinnativo. — Sta.siiopk T. Speeb. 



[Yes, it is the star n, in constellation Piscis Australis, showu near 

 the south-west horizon in map illustration No. 2. — Ed.] 



[23] — Facbe's AccuMfL.\TOB. — Would tho editor oblige a reader 

 of Knowledge by stating how De Faure's battery for the storage or 

 accumulation of electricity is constructed, or in what publication 

 such an account is to be found ? — Nameless. 



[21] — Dreams. — \Vhat position does science take on the subject 

 of dreams ? Docs it deny positively that dreams ever have been 

 sent as warnings, or that the warnings which dreams have appa- 

 rently conveyed have ever been fulfilled except by accident ? I have 

 seen it stated that faith in dream warnings is as much out of date 

 now as faith in astrology. Yet many accounts which have been 

 given of dreams which have been ap|)arently fulfilled, seem scarcely 

 to bo explained away so lightly. — A Dreamer. 



[25] — Forms of Food. — Would not a short article, explaining the 

 meaning of some of the terms used in Dr. Carpenter's interesting 

 article on the " Relation of Food to Muscular Work," be of great 

 use to many whoso studies have not yet shown them the real 

 moaning of such words as hydrocarbons, non-nitrogenous, and so 

 forth f — Desdichado. 



[2G] — Training. — It seems to me that it would follow from Dr. 

 Carpenter's theory of tho " Relation of Food to Muscular Work," 

 that the system of training followed by our athletes is unsound. 

 Ought wenot to return to the system of the ancients, who trained 

 their athletes on barley cakes and oil ? — Oaesman. 



[27] — Effects of Marriage on the Death-r.\.te. — I should be 

 glad if the editor of Knowledge, or any reader who can give the 

 desired information, could tell me how far it has been made out, or 

 whether it has been made out, that marriage acts as a preservative. 

 Is the death-rate of the married lower than that of the un- 

 married ? — Benedict. 



[28] — Stone ox Rolling Wheels. — A long stone is rolled for- 

 ward on wheels 2ft. in diameter, or say 75in. in circumference. 

 There is no sliding, llow far does the stone advance for each revo- 

 lution of the wheels on tho top of which it rests? A mathematical 

 friend says the stone advances 150in. ; but I cannot see how it can 

 advance more than 75in. — Queensland. 



A New Comparison of Poisons. — Comparative experiments with 

 different poisons have often been made bv injecting a given quantity 

 of each into the veins of animals, and noting the effects. M.Richet 

 Ijas recently tried another method (which offers some advantages)— 

 viz., poisoning the medium in which the animal breathes. If a fish 

 bo put in a poisonous solution, it dies sooner or later, according to 

 the concentration of the poison. M. Richet adopts as the " limit 

 of toxicity," the maximum quantity of poison (referred to one litre 

 of water) allowing a fish to live more than -48 hours. This limit he 

 has determined for various metals, always using the same acid 

 radical — viz., chlorides. The limit of toxicity was calculated, not 

 per weight of chloride, but per weight of combined metal. The 

 figures show that there is no precise relation between the atomic 

 weight of a substance and its poisonous power. Copper is t>00 times 

 n^s poisonous as strontium, though its atomic weight is less. Lithium, 

 with an atomic weight only the twentieth of that of barium, is 

 three times as poisonous, Ac. Even with metals of the same family, 

 no relation between tho two things was discoverable. Cadmium 

 (112) is only about half as poisonous ns zinc (tio) ; lithium (17) is 

 70 times as ])oisonous as sodium (23), Ac. Nor could any relation 

 l>o maile out between the chemical function of a body and its toxical 

 power. Thus, potassium and sodium, the chemical properties of 

 which are so similar, have very unequal toxicity ; one gramme of 

 potassium is nearly 250 times as poisonous as one gramme of 

 sodium. M. liichet means to prosecute tho subject further. — The 

 Timvf. 



l\rpUfS to (Dun if g. 



[1] — CiTiMA Thile. — In answer to Query No. 1 in Kxowlelge, 

 Nov. 11, "Alpha Sigma" will find " Ultima Thulc " mentioned in 

 Virgil's " Georgics," Bk. 1, lino 30, in the sense of some remote 

 country. — G. E. F. 



[This qucrj' is answered in a similar way by many corre- 

 spondents.] 



[1] — Ultima Thlle. — The following account is given by Lem- 

 priore in his " Classical Dictionary": — " Thule, an island 'in the 

 most northern i)arts of tho German Ocean, to which, on account 

 of its great distance from the continent, tho ancients gave the 

 epithet of Ullima. Its situation was never accurately ascertained, 

 hence its present name is unknown by modern historians. Some 

 suppose that it is the island now called Iceland, or ))art of Green- 

 land, whilst others imagine it to be the Shetland Isles. Stat. 3. 

 Syh: 5, v. 20.— 6'*ra6. l.—ilela, 3, c. 6.— Tacit. Auric. 10.— Plin. 2, 

 c. 75, 1, 4, c. 16.— rirj. G. 1, v. 30.— Jur. 15, v. iVi.—iioUn. 20.— 

 Servius ad Virj. loco. cit. — W. E. M. 



[2]— A Fifteen Pczzle. — It is easier to solve tho Fifteen 



Puzzle than to give tho demonstration for which " Rusticns " 



seeks. The solution is as follows (or at least this is one solution) : 



Let the fifteen girls be called A, B, C, lic, down to 0, then the 



seven arrangements are these — 



ABC I ADE AFG AHI | AJK ALM ANO 



DIJ BFU BIK BJL ! BMO BND BGE 



EFL CKM CLN COE CDF CGI CHJ 



GKO GJN DHO DGM | EIN EHK DKL 



HMN ILO EJM FKN I GHL FJO FIM 



It is very easy for nine girls to 

 arrangement runs thus— 



out on four days. The 



[1] — The Earth's Inclin.ition. — Were the Earth to rotate on an 

 upright axis, the greatest amount of heat would alw.iys exist at the 

 equator, while the least would be at the poles. At all points of 

 longitude between, the heat would be in proportion to the distance 

 from the equator. I would express it so : perpetual summer would 

 reign at the equator, as tho sun would be always vertical to some 

 point there, and perpetual winter at the poles, as the sun would 

 always be on the horizon. — L. T. F. 



[5]— Hot Winds, Cai'se of. — There is usually an inrush towards 

 hot areas, but at times the action is reversed. There is no reason 

 why at times a sandy region, like the Desert of Sahara, should not 

 become a region of high pressure (especially when we remember the 

 rapid radiation of heat at night), and in that case the tlow of air 

 would be from that region to surrounding regions, the air carrying 

 before it the heated air. Again, the heated air which has flowed up- 

 wards may descend not far from the region of greatest heat, and 

 travel as a hot wind from the hot, sandy region. — Meteobological. 



Nature's Respir-vtob. — The season of cold, raw, damp, and foggy 

 weather is upon us, and many will be its victims. Among other 

 causes, the inhalation of cold, and especially of dirty, air must take 

 a high place. Man is, however, provided with a safeguard against 

 this danger. The double passage to the lungs through the nose and 

 through the mouth suggests some difference in use, and this become 

 certain when we find such a diffei-ence in the two routes as actually 

 exists. The air passing into the lungs through the nose in quiet 

 respiration is wanned as it passes over the lower turbinated bone, 

 with its very vascular mucous membrane, while, as the cavity 

 is so narrow, it is also to a great extent filtered, and in this way 

 deprived of its two dangerous characters even before it reaches 

 the larj-nx. Those, therefore, who in the cold and in the fogs wish 

 to avoid catarrhs should bo careful to inspire only through the nose. 

 With most this will recpiire some practice, but it will bo well repaid. 

 Some, too, will find the impure air of a London fog very irritating 

 to the nasal mucous membrane, and thus a demonstration of the 

 irritant jiroperties of the suspended matter which in breathing 

 through the mouth gets free access to tho lungs may be obtained. 

 Those who arc specially anxious to preserve their voice — as 

 preachers, singers, and judges — stand in special need of this )>re- 

 caution, which is as effective as it is simple, and has many and groat 

 advantages over all the artificial respirators yet invented. — Lancet. 



