Jan. 



1882.] 



KNOWLEDGE 



279 



fiance, thereforp, the vegetable laboratory has been at work 

 |_ before that of the chemist. — SiQCis. 



[214] — VoLT.MC Eleiirkitv. — Is any elementary treatise (with 

 experiments) on voltaic electricity, similar in style to Tyndall's 

 "Lessons on" (friitional) "Electricity" published? — Revneli. 

 W. Hay. 



[215] — Book on Blowtipe Analysis. — Can yon recommend me a 

 good practicable work on blowpipe analysis ? — F. Gbabam Faibbake, 

 O.E. 



[216] — WoRK.< ox BoTAXY. — Would yon acquaint me with the 

 latest work on sysrematic botany, or is there a later edition of 

 Bentham's Botany than 1866? — E. A. Sxeli, M.B. (London). 



[217] — Paf i:oiiOTANY. — (1.) Where can I find Heterangium and 

 Katcz'ilon figured and described ? (2.) Is it dilficult to obtain 

 Sipillaria (internal) ? Any information will oblijre. — F. R. JI. S. 

 [218] — Tennyson. — Please explain the lines : — 

 . , . . " Look you, there is a star 

 That dances in it (the comet)." 



" Harold," Act I. Sc. 1. 

 ..." and over those ethereal eyes 

 The har of Michael Angelo." 



"In Memoriam," Canto 87. 

 . . . " the sea-bine bird of March." 



76iV, Canto 91. 

 May I venture to endorse the sentiments in the Laureate's lines : — 

 " Who loves not Knowledge ? 



May (it) mix 



With men and prosper ! 



. . . Let (its) work prevail." 



" In Memoriam," Canto 114. 



— BrEVERTE. 



iRrpIiesf to ©uerifS. 



[84] — Ancient Max. — Might not the depth at which the " pieces 

 of burnt brick and pottery," &'c., were found, viz., 60 ft., be partly 

 explained by the action of worms, according to the researches of 

 Darwin, as recorded in his latest work ? This would diminish the 

 estimated antiquity. — E. A. Sxell, M.B. (Lond.) 



[130] — Laxguages of the E.\eth. — The languages of the earth 

 are estimated at 3,064, of which 



587 are spoken in Europe. 

 937 „ .. Asia. 

 276 ,, .. Africa. 

 1,264 ,. ,, America and Australia. 



3,06t 

 — Yours faithfully, Jxo. Holmes. 



[146] — The following is the result of experiments with sub- 

 stances injected into the jugidar vein of a rabbit, the urine being 

 collected and aftcr^vards examined : — Maltose is partly converted in 

 the blood into grape-sugar, and partly passes out unchanged. 

 Soluble starch yields dextrin and grape-sugar. Achroodextrin (a) 

 suffers only partial change, grape-sugar and maltose being found in 

 urine, together with dextrin. Acliroodextrin (ji) yields a similar 

 result. Achroodextrin (y) yielded no sugar. We maj' conclude, 

 as a rule, that the changes starch undergoes in the body are similar 

 to those it undergoes when under the action of diastase. Diastase 

 has this effect on starch — viz., that starch, submitted to its 

 action, yields soluble starch, maltose, grape-sugar, and three forms 

 of dextrin, o, ji, and y achroodextrine respectively. The term 

 "achroodextrin " means a dextrin not coloured bj- Iodine. — F.C.S. 



[153] — DouBTFCL Orcaxisms. — The many attempts to define the 

 line of demarcation between plants and animals have all broken 

 down one after another, and modern definitions have no chance of 

 a better fate. Hence Haeckel's group of intermediate forms, 

 which, however, is not followed by most English biologists. 

 Hooker, Cooke, and other botanists regard the ilyxomycetes as 

 vegetable fungi. A newer and probably better view is that of Mr. 

 Saville Kent, who insists on their animal nature as closely inter- 

 mediate between certain tvpes of Infusoria and Sponges. The 

 Hyeetoioa, as he calls them, comprise several genara, as -rEthalium, 

 Stemonitis, Prichia, Arcvria, Lycogala, Didymium. Reticularife, 

 Ac. The subject is one of great difficulty and much interest. — 

 ECLECTICCS. 



[155] — Tortoises. — There is a large tortoise now in Ceylon (at 

 east, I have not heard of its death since I ivas there four years ago) 



which was brought to the island by one of the last Dutch Governors 

 consequently about eighty years before. It came, I think, from 

 .lava, and its age was then unknown, but it was supposed to be even 

 at that time of very great age. I knew it for over twenty years. 

 There was, I believe, an account, with illustrations, of this tortoise, 

 either in the Graphic or Illustrated London News at the time of the 

 Prince of Wales' visit to Ceylon. A turtle was taken on the coast 

 of Ceylon some years since which had on one of its flappers a ring, 

 which, by the date on it, was placed there some thirty years before. 

 — B.M., F.R.C.S. 



[177] — The N.\fTii.cs. — '■ M. Webb " asks the use of the sf- 

 puncJe, or tube running through the septa, or partitions of the shell 

 of the pearly nautilus. This tube is believed by some to have the 

 function of maintaining a low vitality between the disused chambers 

 of the shell. Others say that it is used to alter the specific gravity 

 of the animal, and that by receiving or expelling fluid from or to 

 the body, in which it terminates, the nautilus is enabled to sink or to 

 swim in the sea. The exact functions of the sipnncle are, I believe, 

 still unknown. — AxDREW Wilson. 



[165] — Horseradish. — This herb, I believe, possesses merely 

 astringent and stomachic properties. Its use as an adjunct to 

 food corresponds with that of mustard, and it may, therefore, 

 assist in stimulating the flow of gastric juice. — Andrew Wilson. 



[169] — Light and Laxterx. — 1. Tyndall's " Six Lectures on 

 Light," delivered in America (Longmans, London, 1875). 2. 

 " Light," by Mayer & Barnard (Appleton & Co., New York, 1878). 

 3. " Art of Projecting," by Professor Dolbear (Dillingham. Xew 

 York, 1877). 4. "Optics for the Lantern," by Lewis Wright 

 (Macmillan, London, 1882). — Tnos. S. Bazley. 



[180] — The Pole. — The reply given to the question, " How 

 Arctic explorers could tell exactly when they reach the pole ? " 

 (p. 234), can only apply to the (nearly) six months that the sun is 

 invisible at the pole, for during the remaining half of the year, the 

 constant sunlight would prevent any astronomical observations of a 

 star being taken, as no stars could be seen. If the pole is ever 

 reached, it is likely to be during the time of sunlight there, and it 

 is, therefore, by observations of the sun's altitude at different 

 positions round the heavens — correcting such altitudes for changes 

 of the sun's declination during the intervals of observation — that 

 the explorer will be able to tell, with very considerable accuracy, 

 when he has arrived at the extreme north of the world. — J. Rae. 

 [That is one method among many ; but, after all, determining 

 when the pole is reached is really determining the latitude. At any 

 time, the latitude can be determined by taking the sun's apparent 

 altitude at noon. If this, corrected for refraction, &c., =A, and 

 sun's declination (north position) at the tiine = o, then the latitude, 

 X, is given by the formula — 



\=90°-(^-fl) 

 At the pole, where the latitude = 90, we have — 



A = S 

 So that if the sun's observed noon altitude, corrected, is equal to his 

 known northerly declination, the observer is at the pole. — Ed.] 



[182] — Evergreens. — I believe the origin of the "evergreen" 

 condition in plants is traceable to the general principles which 

 regulate " natural selection." If we suppose that any plant 

 during its spring and summer life acquired gradually an extension 

 of its period of active nutrition, along with a fixation, so to speak, 

 of the products of nutrition in the leaves (chlorophyll, &c.), the 

 origin of the evergreen state is not difficult to conceive. We find 

 an analagous case in the storage of starch as reserve-material in 

 bulbs and tubers. Such a food-supply enables a plant (like a 

 person with a deposit-receipt at his bank) to flower earlier than 

 its neighbours, and there is no difficulty in conceiving that this habit 

 of storing food may have grown and intensified by slow degrees. — 

 Axdbew Wilson. 



[184]— Aluax.^cs and Celestial Maps.— Middleton's Atlas is 

 published by Wliitaker & Co., Paternoster-row ; Gall's (only a 

 shilling), by Gall & Inglis, 25, Paternoster-square. Both are 

 superseded by Proctor's 'Half-Hours mth the Stars" and 

 " Library- Atlas." — Thos. S. Bazley. 



[188] — Optical Illcsion. — This is very antique ; it isthesh<idoi« 

 of the pin which is thrown on the retina, and not being inverted, 

 is paradoxically seen upside down. — S. J. 



Electric Clocks. — A system of electric clocks has been organised 

 for Genoa, and is now being carried into execution. The clocks 

 will be arranged in five distinct lines, all branching out from the 

 Municipal Palace. The first will extend to the Porta Lanterna ; the 

 second to the Molo Yecchio ; the third to the Carignano ; the 

 fourth to the Palazzo Tommaseo ; and the fifth to the Piazza Manin. 



