146 



• KNOVV^LEDGE ♦ 



[Dkc. IC, 1881. 



[52] - MirRo*u-<irK. --Ono of tho kind callo'i n»o<liriil mirroscopop, 

 baviiift tho body-tuho alidinK in tho stnnd, nnd in two pnrtn. Tho 

 objoctivcH Rhuiild bp mndr to slide into position nnd not to screw — 

 it anvrs time. ThiH niiiroKCO|>o permits n, more rapid chnnifc of 

 ampliliration, while stiM giving all other facilities for work as well 

 ns any other. — Pai'gi'l. 



|6iJ — CliKMK'Ar, QuKSTiON.i. — The expIn.nntion of (I) given by 

 C. T. B. is viry good, but he is wrong in supponing tlwt hydro- 

 ferrocynnic noid has not boon isolated. Mr. Thoophilus I'itt accuses 

 " Ca»tor nnd rulhw " of being "inattentive" and "careless," 

 adjectivoa which arc very applioiiblc to himself, as he has misread 

 tho qaostion, or else he is ontiroly ijjnorant of the faot that am- 

 monia and hrdrosulphuric noid form ammonium unlphide ; and ho 

 apparently thinks that feiTocyanido of pot.issiura should give a pre- 

 cipitalo with ammonia and ummoniuni sulphide, which is a serioua 

 mistake. With rogjird to quosti-n (2), C. T. li. suggests that tho 

 eolation might be alkaline. How can a solution of potassium bi- 

 galphate be alkaline ? Tho true explanation ia that tartaric acid is 

 unablo to displace sulphuric acid from potassium bisulphatp, al- 

 though it cjvn take up one equivalent of potassium from the neutral 

 sulphate (K„SO.,), forming bisulphate (KHSO.,), and bitartrato 

 (KHC,H.,0„). Potassium iodide should give a precipitate if tho 

 solutions are strong. The tartaric solution ought to be very strong 

 (1 part in 4 of water). A solution of platinum tetrachloride is a 

 far more delicate and reliable test for potassium j it should be used 

 in tho same way as tartaric acid, and, like it, also precipitates 

 ammonium salts. — E. F. H. 



[55] — Tabi.e.s of Merioional Pakts. — The meridional parts in- 

 serted in most works on navigation, as in Noric, Bow^ditch, Inman, 

 Bajwr, Chambers. 4c., arc very old, and were computed for com- 

 pression 0, in fact, for the earth as a sphere ; these differ among 

 themselves only in so far as Chambers and Inman give tho quantities 

 to two places of decimals. Mendoza Rios used compression -g^j, 

 and these are the tables givon by Riddle. Riimkcr used compres- 

 sion 3^3, and are the samo as given by Caillet ; but, by far tho best 

 table of meridional parts is that given in the " Projection Tables " 

 computed for the United States Coast Survey Department and 

 Hydrographic Office, and reprinted in England in the last edition of 

 Eaper's " Nautical and Logai'ithmic Tables " ; the compression is 



here taken as , based on Bessel's determination. — ^W. H. R. 



299152S 



[56] — Roscoo and Schorlemmer's " Tieatise on Chemistry " (Mac- 

 millan). — Alfred J. Shilton. 



[58] — Smros and Oeion.— The statement was, of course, wrong. 

 Betelgoux must have been meant. — Paugul. 



[62] — Algox. ^Perseus is represented as holding tho head of 

 Medusa ; the stars he mentions are one. — Paugul. 



[C3]— Algol and Miea. — Mira was at its maximum early last 

 Jnly, and will be a month earlier next year. Algol every couple of 

 days. — Paugul. 



[65] — New Star in CAssioPEiA.^We do not know. A staj- has 

 been seen, or is said to have been seen, two or three times in or 

 near Cassiopeia, at such dates that, if correct, it ia nearly due now. 

 That is nearly all we are able to say ; a small star has certainly 

 been seen lately in Cassiopeia where one was not noticed before, but 

 it may have nothing to do with the supposed variable. — Paugul. 



[77] — Horrible dbkams are often dne to the quantity and 

 quality of food taken at supper. I think Pliny tho younger tolls 

 you to eat heartily of roast pork just before retiring if you want 

 horrid dreams. The worst dream I ever had was due to pickled 

 cabbage and cheese just before going to bed. The results are 

 thought to be duo to pressure on the solar plexus of nerves in the 

 abdomon, which set up some irritant action in the brain. To 

 avoid bad dreams, oat light suppers, at least three hours before 

 retiring ; take a little gentle 6.xercise if possible, and avoid startling 

 romances .it night. — T. R. Allinso.n, L.R.C.P. 



[79]— Mental Puysiology.— " S. S. S. S." should have stated 

 lujw far ho wished for works of a "specialist'* physiological cha- 

 racter. Outside these, 1 don't think he can have a later, or a better 

 or more complete work on tho mental side of tho subject (and which 

 gives references to all needful works) than " An Inquiry into the 

 Process of Iluman Experience, &e.," by 'WUliam Cyples, published 

 by Strnhan & Co., 31, Paternoster-row, price 21s.— S. 

 ■- [79]— Mental Phvsiologt. — Dr. Carpenter's "Mental Physio- 

 logy " is a capital book. " S. S. S. S." should look over the list of 

 tho " International Seicnco Series" (Kegau Paul & Co.) for several 

 works on tho brain and mind. Dr. Mnudsley's books on mental 

 subjects will also be found very useful by a student of mental 

 science. —Aniibew Wilson. 



[83] — In answer to (a), Berthelot describes tho powdery form of 

 sulphnr in vol. xlix. of " Annales do Chimie." It is formed also at 

 tho zincodo of a battery, in the electrolysis of sulphurous and 

 sulphuric acids, (b) Nitric oxide in ine.'»nt. — C< T. B.- 



[83] - SuLniuR Modification. — Tlicrc- air- five modifications of 

 sulphur known. The two crystalline forms, the plastic form, a dark 

 brown powder lift on treating the plaxtic form with CS,, and a 

 light yellow powder insolnble in CS, (c/irbon disulphidc) dop<j«ited 

 from solutions of sulphur in CS,, on being allowed to stand. The 

 above is from " Roscoe and Schorlemmer's Chemistry," Vol. 1., 

 paragraph 156. (C.) It should be ftitric oxide.— A GBEF.Ninr ii 



STUDENT. 



[81] — Anciknt Man. — "Clio" (Query 81, p. 123) desires some 

 infomyilion as to the reliability of the researches o^ ProfesK^ 

 Horner. The Professor published them in 1851. He states thati 

 made ninety-five vertical borings in the alluvial deposits'of the Nil 

 valley, and at the depth of 39 ft. fragments of pottery were found, aiL 

 the conclusion drawn is, to use the Professor's own words, "if the^ 

 is no fallacy in my reckoning, these fragments of pottery most 1 

 held to be a record of the existence of man 13,000 years ago.'' ~ 

 whole data of his conclusion rests upon the assumption that tU 

 deposit of the Delta was gradual and uniform. This he assuma 

 from calculating tho interval between B.C. 1450, the time of th 

 erection of the statue of Ramesos II., and the time at which tn 

 exploration took place. And judging from the thickness of tn 

 deposits around the statue, from its base npward.s he infers th 

 the Delta accumulated, if my memory serves me, at tho rah 

 of two and a-half inches a century. It will be perceived 

 that this calculation takes as its basis that the accumulation was 

 successive ; but we have no means of ascertaining how far the 

 base of the statue stood above the reach of the inundation when 

 first put up, and so have no basis for any calculation. Again, the 

 water of the inundation having been for ages kept out, according to 

 Egyptian custom, from the enclosure in which the statue stood, the 

 accumulation of the deposit there was the more rapid when, in aft4r 

 times, the water was admitted. This accounts for the thickness 4f 

 the sediment without any successive deposit. Herodotus (Book it, 

 p. 99) mentions that Mencs, first king of Egypt, ii.c. 2350, was 

 supposed to have diverted the course of the Nile by a dam twelve 

 miles south of Memphis, and thus to have dried up the old bed. It 

 may be that tho statue of Ramesos 11. stands on the old bed, and 

 the fragments of pottery were depo-«ited by after inundations. Legs 

 than n thousand years ago the Nile flowed close to the western 

 shore bf Cairo. It is now separated from it by a plain more than a 

 mile in width. At a depth of 30 ft., fragments of pottery were 

 found Jess than a thousand years old. Professor Horner says that 

 "fragments of burnt brick and pottery were brought up from the 

 lowest part, viz., 50 ft. from the surface." Now it is an undoubted 

 fact that there is not a single structure of burnt brick from one 

 end of Egypt to the other, earlier than the Roman dominion. Mr. 

 Birch, the Egyptologist, refers the burnt brick to B.C. 1300. On 

 these and other grounds I think it may safely be said that the 

 evidence for man's existence as derived from the researches of 

 Professor Homer is not reUable. — R. S. Corcn. 



[88] — Brain Injuries.— The brain is divided into two parts. One 

 controls involuntary motion, as breathing, tho heart's action, 4o. ; 

 tho other is used for thought, the reasoning powers, and passions. 

 The brain is also double, so that, injure one part, and the other side 

 takes np its action. This is true with the reasoning and thinking 

 powers. Injure a part governing any member, and yon Bee at once 

 paralysis of that member. From this is inferred that injury to the 

 intellectual part is not followed by any noticeable change, l)ut 

 injure any of tho motor parts, and yon got at once paralysis. Thv 

 brain is the organ of feeling, in that it makes us aware of injuries 

 inflicted anywhere on the body : so that we make an effort to 

 remove the injured part from the irritant. — T. R. Almnsok, L.R.C.P., 

 ic, 2, Kingsland-road, E. ', 



[90] — The lx>st theory is, th»t the earth is an elect*o-magnet ; 

 currents of electricity travelling round at about right angles to the 

 axis. If is ba.sed on the fact that lodes of metal.^ generally lie in 

 the same direction, and they would be able to keep np thermo- 

 electric currents at the expense of the earth's heat. This theory 

 does not explain magnetic variation, — C. T. B. • 



[105] — A Question of Geamsiar. — " A. T. C." will, perhaps, 

 nnderstand the phrases, "I can but think "and "I cannot bat 

 think," by remembering that the word " but " is used in three 

 senses : — (1) As an .adverb = " only," as in " I can but think " ; (2) 

 ns a conjunction, its most common use; (3) as a preposition = 

 " except," as in " I cannot but think " — this expression being ellip- 

 tical, for " I cannot do any other thing but think." In this last 

 case (which, by-tho-bye, some older gramm.arians ignore) " but" is 

 the representntivG of the Anglo-Saxon bWaii = without ; and is used 

 by Chancer in tho lines : — 



" But meat or drinke, she dressed her io lie 

 In a dark corner of tho house alone." 

 The broad Yorkshire dialect has such expressions as " I can do bout 

 it " ; where the " bout " is not merely a corruption of " without," 

 but the old Anglo-Soson • " but." —J. H. I* 



