Keb. 10, 1882.] 



• KNOWLEDGE 



325 



1 Wetting with ammoniii acts better. A ling worn lias 

 .1 burning.— C. T. B. 

 - 1 0] — HoMKR. — Both the " Iliad " and the " Odyssey " are pub- 

 I in prose in Bohn's Classical Library, price 5r. each. — C. J. C. 

 -13] — Organic Compounds. — "Siquis" should road Borthelot's 

 iiiiic Organique fondee sar la Synthase," Paris, 1860. Sec also 

 ii;;o," &c., in last number of Knowleugk. Alizarin (cliief 

 r ing matter of madder) got by Gnebe and Liebermann from 

 leenc. This can be built up from its elements. If " S." will 

 , will gladly show how.— C. T. B. 

 -Is] — Tennyson. — " In Mcmoriani," pecm S7 : — 

 " And over those ethereal eyei! 

 The bar of Michael Angelo," 

 1-0 brow was straight and prominent, the .si^;!! of intelleelual 

 ■ r. I6i(f, poem 91 : — 



" The sea-blue bird of March," 

 kingfisher, which like other birds, puts on its best plumage in 

 spring. — Vide " Key " to " In Memoriam," by Alfred Gatty, 

 -I'.B.F. 



IS] -"The bar of Michael Angolo" refers to the peculiar 

 ■let ion of the forehead, forming a wrinkle, seen in the old 

 :!its of Michael .^ngelo. Arthur Uenry Ilallam, referred to in 

 iiDtation, had this same mark on his brow. — JonN Ckaig, JfX. 

 -!s] — " Se.\-bli'f. bird of March." — Kingfisher (C. Karen no). 

 " These fields made golden with the flower of March, 

 The throstle singing in the feathered larch. 

 * • • * • 



And down the river, like a flame of blue, 



Keen as an arrow flies the water-king." — Ouijk.is. 



-I'l] — The Atomic Theory. — Daubeny's "Introfluction to the 



.-.c. Theory," O.\ford, 1850, is the best English work. There 



ilicory to explain insolubility ; bodies of similar chemical con- 



' ion dissolve each other. — C. T. B. 



-JO] — Chemical Analysls.— The most complete book on Quali- 



' .\nalysis is by C. R. Frescnius, translated into English, and 



-lied by Churchill, at 12s. Cd. The methods, however, are 



I', and take up more time than most students can spare, but 



are the best and most trustworthy. A very good book on the 



subject is " Practical Chemistry," by Jones (Macmillan, 



' ;.). In " Quantitative Analysis" (inorganic), by far the best 



most complete is Fresenius's (Churchill, ISs.); the large 



' -r of methods and quantity of matter is, however, confusing 



'• beginner, unless under the guidance of a teacher. On the same 



t, Thorpe's is very good (Longmans, 4s. 6d.). If agricultural 



istry is wanted, there is Church's Laboratory Guide (Van Voorst, 



' 1.) ; the first part is qualitative, the second quantitative. The 



1 ird work on Volumetric Analysis is Sutton's (Churchill, 15s.). 



I ' immercial Organic Analysis we have Allen's, of which only 



I rst vol. is published (Churehili, about 15s.). " Practical 



Mistr)'," by Blyth, is an excellent work on foods, drinks, and 



ilogy (Griflin, about 12s.). "Wanklyn has written separate 



I treatises on the analysis of water, milk, tea, coffee, and 



1 (Triibner) ; " Water Analysis " — Frankland (Van Voorst); 



rrable Water" — Ekiu (Churchill); "Butter" — Hehner 



inhill, 3s. Cd.); "Commercial Handbook of Chemical .\nalysis," 



N ' rmandy, is in dictionary form (Lockwood); "Select Metliods 



iiialysis, by Crookes (Longmans, 12s. Cd.); "On Microscopic 



ysis of Foods," Hassell's is the best (about 21s.). There 



: number of important articles on food analysis in the Analii>.t, 



lithly magazine (Bailliere), which every food analyst should 



Do not confine your attention to any one book on water 



-is ; it is necessary to read Wanklyn's, but analysts do not 



vv it throughout. , There are so many works on qualitative 



sis that it is difficult to say what are the best. — A Fellow of 



Chemical Society. 



-lili] — Mortality from Cancer. — 11. A. Everest will find in 



land's work on "The Geographical Distribution of Heart 



i-e. Cancer, and Phthisis, in England and Wales," illustrated 



jlourcd maps, the facts proving that cancer is influenced by 



)iy. The above work was published in folio in 1875. It is 



ut of print, but can be obtained at second-hand booksellers, 



-een at the Library of the British Museum. 



i.''tter 220] — The Health of Navvies. — In Xo. 12 of Know- 

 F, I find bctel-nnt chewing given as a specific against fevers, 

 ■'avanesc and Snndanese are inveterate betel chewers, and yet 

 have been dying literally by thousands during the past few 



i - from fever. When I left Samarang, Java, in September last. 

 I ativcs were dying by hundreds of fever. My experience, 

 ■cling over nearly four years in various parts of Asia, has been, 

 the natives who universally chew betel (with lime, and the 



' ■if the sirih-pepper-plant) , are much more easily affected by 

 !■ than are Europeans. — Ei>win Sachs. 



gns;U)ri£( to Coiiteponlifnts!. 



bffo. 



tncreasing t 



HlNT8T< 



I be a:i 



attons for the Editor requiring early attention rhoitlJ reach the 

 the SiiturJai/ preceding the current iuite qf KkowikdoB, the 

 rculutioti oftchich compete im to go to preee early in the Keek. 

 ConnisrONDKNTS.— 1. A'o queilioua ailcing for Icienlijic iriformalioa 

 red through the poet. 2. Lettert tent to the Editor for corretpondentx 

 cannot be fonearded ; nor can the naniee or addrcngee qf correspondents he given in 

 aneteer to private inquiries. 3. No qnertes or replies savouring qf the nature of 

 advertisements can be inserted. 4. Letters, queries, and replies are inserted, unless 

 contrary to Rule 3, free of charge. 6. Correspondents should Krite on tme side 

 only of the paper, and put drawings on a separate tet\f. 6. Each letter, query, or 

 reply should have a title, and in replying to letters or queries, reference should be 

 nade to the number of letter or query, the page on which it appears, and its title. 



S. S. G. See Dr. Ball's paper in our next.--C. Ichabod W. 

 Kindly put query in concise form. — Walter W. It would save 

 much trouble if you would either put your queries in form, with 

 heading, Ac, or head your letter properly. Does moonlight really 

 make the planets and their satellites more distinct ? That three-inch 

 IS a splendid telescope. Having .seen Kigel, as described in " Half- 

 hours with Telescope," know that it can bo so seen. Possibly the 

 objects you refer to were observed under unfavourable conditions. 

 A new edition of Webb's "Celestial Objects for Common Tele- 

 scopes " has been published lately. — Joseph Davidson. There is 

 Rodwell's " Science Dictionary," Moxon's, price 10s. 6d., I 

 believe.- E. Vf. Propose to re-write the articles on the 

 " Differential Calculus," with sundry improvements which have 

 occurred to me. — Zares. When did we say that a tangeutially 

 (horizontally) moving mass has no energy ? If a fly pushed against 

 a mass a ton in weight so sus])cndcd as to be perfectly free to move 

 in the direction in whic:li the lly pushed, he would communicate to 

 the mass just so much momentum as corresponded with the force 

 wherewith he had pushed it. Or conceive half a ton of matter 

 connected with another half ton by a strong but weightless cord 

 passing without friction over a jiulley, and lot a fly light on one of 

 them. Let his weight be one-ten-millionth of a ton. Then the 

 weight on which he lighted would immediately bcgiu to descend, 

 the accelerating force being one-ten-millionth part of gravity. In 

 10,000,000 seconds, or 115"days, 17 hours, C§ minutes, the velocity 

 communicated would be 32 feet per second — that is, the same 

 velocity which gravity communicates to a falling body in one 

 second. It would take rather more than 34 days to communicate a 

 velocity of one foot per second. As to your offer of £o prize to 

 determine what force would overcome the inertia of a pound of 

 iron, we are much obliged to you, but must decline. Wo repeat 

 your other query ; we might safely offer a prize ourselves to any 

 correspondent virho can understand what you mean. You require 

 " the summation of the infinite number of infinitesimal difi'erences 

 between and 1, of which 0-5 is the intermediary or I." The sum 

 of the differences would simply be 1. You do not mean that, how- 

 ever, for your original query asked for the sum of tho series to 1, 

 when the number of terras is infinite. That sum, if there were such 

 a series, would be infinite. You say I " dare not say " two ships 

 unequal in mass, moving with equal velocity, could both be 

 stopped with the same resistance : I dare say not. — F. Blake. 

 Your method already given. But for the jiresent we have 

 done with magic squares.— Granville Sharp. You are more sharp 

 than generous or reasonable. Before you spoke of my "foolish 

 utterances" in the Spectator, you should have made sure they were 

 mine. As it chances, they are not, nor do they in the slightest 

 degree represent my views. Seeing how rashly you rush to con- 

 clusions, I am almost pained to think you ever thought well of my 

 work. How sad to think that your past liking may have been as 

 ill-founded as your present disfavour ! — H. A. B. Statement in- 

 sufficiently exact; you say nothing of size of building and height; 

 you do not define your " very near."— G. E. R. Science knows of 

 no wav of inflicting pain on persons at a distance, " notwithstand- 

 ing such obstacles as closed doors and windows, without any visible 

 means." The stories about such action at a distance are 

 generally thought to illustrate tho influence of imagination. — 

 F. E. B. The writer of " Brain Troubles " has some singular 

 experiences to relate respecting music in the ears ; the pheno- 

 menon is unquestionably subjective.— O. Dawson. Pray define 

 inferiority (in the Man versus Woman question), man (in the 

 Descent debate), true (in the Phrenologj' discussion), and justice— 

 in your own w.iy. If you had any conception of the value 

 of time, yon would" understand what our definition of injustice might 

 be. We have no time for hair-splitting, and it is unjust to expect us 

 to follow yon in yours. We could find space for a short letter 

 giving your definitions, and commenting (at reasonable length only) 

 upon what you regard as the inexactness of others. — Clericls. Wo 

 receive letters from .\merica which are printed by somo new form 

 of ty])e-writer, probably the one to which you refer. Perhaps some 

 of our readers can give us information about tho new, cheap 



