March 3, 1882.] 



KNOWLEDGE 



371 



MAGAZINE OF SCIENCE 



PLAJNLrWORDED -EXACTLY DESCRIBED 



LONDON: FRIDAY, MARCH 3, 1882. 



Contexts 



PJIGB. 



A SluJvin Minute Lif.>. Bv Henn- 

 J. Slick. F.G.S , F R.M.S :. 371 



ThpCnr9t»l Pslacp Elpitriciil Eihi- 

 liilion. Fourth Nolice. (IHutt.) . 372 



Venlilation bv On»n Fireplacei. Bv 

 \V. Mallieii WiUiami f. 373 



The Klectrii- Telegraph. ByW. Lynd 374 



Nighu with n Three-Inch Telescope 

 (lUuttrol-J) 376 



A Spinninii-Top 376 



Rbtisits : Electricitv and Mag- 

 neli^m— Spelling and Punctuation 

 —Geometrical Eiercises for Be- 

 Cianara — Dr. Luys on the Brain— 

 (3anofs Physics 377 



Were the Ancient Etryptians ac- 

 quainted with the Movement of 

 the Earth? 379 



Malarial Organisms in the Blood ... 379 



OF No 18. 



PAOV. 



The "Sound" of Fishes 38i) 



The Pvramid of Mevdoom. Bv Miss 

 Amelia B. Edwards ' 380 



A Pretty Geometrical Problem 380 



j Intelligence iti Animals 380 



A Cnruivorous Parrot 331 



I Jacko: A Baboon's Biography 331 



I Changes on the Surface of Jupiter. 

 ' BvProf.C.W.Pritchett, Glasgow, 



, Mo. r.S.A 392 



I Star-Map for March S34-M5 



' COBRE:>P0XDEXCX 337-3.S9 



' Qneries 839 



I Replies to Queries 39i) 



Answers to Correspondents 391 



Notes on Art and Science 393 



, Our Muthematical Column 391 



; Onr Whist Column 394 



I Our Chess Column 3% 



A STUDY IX MIXUTE LIFE. 



By Henry J. Slack. RC.S., F.R.M.S. 



^pHE interest to lie derived from the use of the microscope 

 X soon passes away unless it is accompanied with some 

 scientific tlunking about wliat is seen. With the help of 

 such thinking, there is no end to the combinations of amuse- 

 ment and instruction that was pre\-iously gained. Suppo.se, 

 foi' cxaniple, one of the oldest experiments is made, that 

 of putting a little wisp of liay into a vessel of water, and 

 noticing what happens. In a toleralily warm place, many 

 hours will not pass before a sort of skin forms on the 

 surface of the water, and after thi.s soon appear a swarm of 

 moving creatures, il. Pouchet called tliis skin a proli- 

 ferous pellicle, and ascribed to it a kind of maternal power 

 in generating the animalcules that come after it. This 

 notion he connected with a theory of creation in which at 

 some imaginary periods of great cataclysms and catastrophes, 

 prodigious putrefactions and decompositions occurred, and 

 out of the seething mass arose monstrous forms. 



Gorgons, hydras, aiitl clumeras diiv. 

 The fact, however, is, that the quantity of the decomposing 

 material has no direct action upon the kind of life that 

 appears, and that a gi-eat many creatures neither want 

 putrefaction or its products, liut are injured by the pro- 

 cess. The chemical changes that occur in fermentations, 

 like that of sugar into alcohol and carbonic acid, or in 

 decompositions that by no means charm the nose with 

 pleasant smells, are caused or promoted by living organisms : 

 in the cas > of yeast-cells, resembling little bladders, and in 

 other cases, minute rods or wriggling spirals. It is not, 

 however, with these micro-ferments that we are now con- 

 cerned, but with liigher forms that are sure to be found 

 injuriou.s, but which can be well developed in water that 

 contains their appropriate nutriment, but remains sweet. 



It is best, when varieties of minute life are required, to 

 operate on a tolerablj- large scale, sa}' a good handful of 

 hay in a gallon of water, but a pinch of it in a tumbler 

 is sure to yield a good harvest, and germs of various 



organisms are so widely ant! commonly distributed that 

 SUCCOS.S may be obtained with a grain of chopped hay in a 

 quarter of an ounce of water. In such small experiments 

 a two-drachm vial answers ^'ery well In a shallow vessel 

 the water dries up too quickly. The student need not at 

 first trouble himself with the particle or with any object 

 not big enough to be easih' seen with an inch power, or at 

 most a half-incli. An accurate stock of general ideas 

 and broad principles should be acquired before atten- 

 tion is directed to the most minute structures. Before 

 taking much trouble to identify the various objects 

 and learn their names, it will lie well to notice certain 

 peculiarities of structure. A crowd of little restless 

 creatures is sure to be seen in the infusion mentioned, 

 and their movements are produced by hair-like projections, 

 called cilia, no other external instrument being visible. 

 Their runnings to and fro ari- incessant. Whenever they 

 are looked at, by day or night, their acti\'itv is striking, and 

 until they liecome weak or dying their pace is maintained. 

 While the cilia are in quick movement, it is impossible to 

 see exactly what they are and what they do. If, however, 

 a g(X)d-sized specimen of any ciliated object is allowed to 

 get nearly dry, and consequently enfeebled, the motion of 

 the organ can be plainly discerned. For our purpose a little 

 drop of water containing some of the creatures should 

 be placed on a glass slide, covered with thin glass, 

 and the object watched under the microscope until, from 

 vigorous movements wliile there is plenty of water, they 

 grow languid and slow as e% aporation from the edges of 

 the covering glass lessens the supply. A cilian is then 

 observed to move much in the way we can imitate with an 

 elastic stick about a yard long, and ha\'ing an impulse 

 given to it by sharp turns of the wrist. There is a wave 

 motion from the bottom to the top of the cilian like that 

 wliich can be made to agitate the ttexible stick. As cilia 

 are usually very numerous and close together in the sort of 

 olijects under our notice, it is eWdent that if they did not 

 move rhythmically and in a thoroughly orderly way, they 

 would be in frequent collision. This would be very 

 awkward if the purpose to be served were only, as with 

 many species, the production of water currents to bring 

 them food, and it would be quite inconsistent with 

 the rowing action required for locomotion. A common 

 species is very conspicuous in the Paramecium aurelia, an 

 ol)long little creature ranging in size from a little more or 

 less than 1 -100th of an inch in length. It possesses 

 longitudinal rows of cilia ; Ebrenberg found some fine 

 specimens with as many as fifty-two of these rows, each 

 containing from sixty to seventy cilia, making 3,610 in 

 in all. Each cilian rises from a minute knol>, which, 

 though not containing positive muscular structure, acts 

 like a nicely-arranged combination of muscles. Tliere is 

 again no nerve cell, but the whole group of organs is made 

 to work harmoniously by some undiscovcrable, but no 

 doubt most methodicaUy-arranged, groups of molecules, 

 which receive impressions from their surroundings, and 

 stimulate the contractions and expansionsbj'which the move- 

 ments are produced. If we were furnished \\ith three or four 

 thousand limbs whose use and movements had to be divided 

 by our intelligence and our will, we might be a long time 

 learning how to get on without grievous mistakes. In the 

 case of the infusoria, we cannot imagine anything like 

 human volition or purpose, but one as high in the ranks 

 of life as a Paramecium has to use its army of external 

 organs for these purposes, to produce currents of water 

 so that fresh streams continually reach its surface and pro- 

 vide amply for its respiration, so that the minute objects 

 that serve for its food may come within reach of its mouth 

 and be swallowed, and that the cilia particularly engaged 



