230 



KNOWLEDGE. 



[October 1, 1897. 



it is only necessary to regard tbem side by side with 

 specimens of good Greek work to see how wide the gulf is 

 that separates them. Etruscan art has certain character- 

 istics that infallibly distinguish it from Greek, and demon- 

 strate the utter baselessness of the notion that what we 

 now recognize as vases of Greek manufacture can ever have 

 been produced in Etruria. The drawing is either over- 

 elaborated and full of stiff mannerisms, or else helpless and 

 ugly, while the style is altogether dry and lifeless. More- 

 over, the execution is manifestly inferior even to the 

 Grasco-Italian vases, with imperfect black glaze and dull 



yellow clay. In point of date 

 these vases belong to the 

 second and third centuries b.c. 

 Greek mythological subjects 

 are popular, but local deities 

 are also introduced, such as 

 Charun, the Lasas, and other 

 conceptions of Etruscan reli- 

 gious belief. On several of 

 these vases inscriptions in the 

 Etruscan alphabet are found. 



Some vases of this period 

 are archaistic in character — 

 that is to say, they are de- 

 liberate imitations of primitive 

 or black-figured fabrics. Others 

 illustrate the tendency of the 

 period to strive afterneweffects, 

 either by new methods of 

 painting or by the addition of 

 reliefs (as on Fig. G) or 

 stamped patterns, or, again, 

 are moulded into the forms of 

 human beings and animals. 

 In the direction of a new 

 style of painting, the most important is a group of vases 

 found chiefly Ln the neighbourhood of Tarentum and 

 Egnaaia, and occasionally in the Greek islands (sec Fig. 5). 

 The whole vase is covered with a black glaze, on which a 

 white pigment is applied, the eii'ect being enhanced by 

 details in purple and yellow. The tendency is to reduce 

 the labour of painting to a minimum, and the subjects 

 are generally confined to the upper part of the vase and 

 limited to simple decorative motives, such as a bird or a 

 mask. 



Vases with reliefs or moulded into various forms are not 

 exclusively characteristic of this period, as many such 

 belong to the finest stages of Greek ceramic art, or even 

 to a more primitive phase ; but in the third and second 

 centuries their number becomes much larger in propor- 

 tion to the painted vases. Nor are they found only in 

 Italy, as numerous examples occur all over Greece down 

 to comparatively late times. Many of these vases are 

 imitations of metal, and appear to be copies of popular 

 works in silver and bronze, made for those who could not 

 afford the more expensive material. This is especially the 

 case with a series of bowls, found chiefly in Greece, which 

 have figures in relief on the outside, the subjects being 

 often taken from the Homeric poems or the plays of 

 Euripides. We read in Suetonius that the Emperor Nero 

 possessed "Homeric bowls" of silver, which were probably 

 decorated in this fashion. These bowls may be regarded 

 as the prototypes of the Aretine bowls which become so 

 common in the Roman period. Many of these vases with 

 reliefs actually bear the names of Koman potters, and a 

 small class of cups with simple painted decoration have 

 early Latin inscriptions painted on them, with dedications 

 to various deities. 



Fi8. 6.— Lekrthos (Oil 

 Flask), ornamented with 

 figures in relief, representing 

 Ajax seizing Kassandra. 

 Third century B c. 



THE PRIME MOVERS OF NERVE AND MUSCLE.* 



AMONG the wonderful phenomena which this little 

 world of ours presents to the inquiring mind, 

 that which constitutes the distinctive feature of 

 animated nature — activity in all its forms — appeals 

 to our admiration most forcibly, and it loses 

 none of its interest when intellectually considered. If 

 evidence were required to establish the veracity of such a 

 statement we should find it in Sir William Gower's little 

 book — " The Dynamics of Life." 



Search as we may, that which we call life eludes our 

 grasp, and resists our efforts ; we see it dimly shadowed 

 now and then within the luminous mist, but the mist 

 obscures our sight, and the light it radiates hides, as it 

 were, by its own brightness ; we can trace it through many 

 an intricacy, but the point is soon reached where that 

 which we can trace is limited by that of which we can 

 only see the effect. Still, if hypothesis enables us better 

 to discern that which is in sight — to discover more of its 

 details, to see its relations more clearly, to grasp its 

 character more firmly — the result is surely worth an effort, 

 and there can, therefore, be no harm in trying to push 

 our way, so to speak, as near as possible to the source 

 of vitality. 



What, then, is the source of (he energy that is mani- 

 fested in the animal body, and in the processes of human 

 life — from a sigh to a convulsion ? Whence ami how is 

 motion produced by the muscles '? and whence is the 

 mysterious nerve force derived that excites the muscles to 

 contraction '? At the outset it should be understood 

 that, according to modern science, no energy can be 

 manifested which does not exist before in some other 

 form. The energy that is made manifest, alike in the 

 combustion of coal or in muscular action, must exist 

 before as a definite form of energy — inconspicuous it may 

 be, but not less real. 



In the light of Tyndall's classical researches we are 

 compelled to believe that in every substance about us 

 there is the minute motion of heat corresponding to its 

 temperature. We know that not only may a piece of iron 

 be the seat of the atomic motion we recognize as heat, 

 but it may also be the seat of the atomic motion of 

 electricity, and can be made the seat of the atomic motion 

 of sound. If we consider a piece of glass instead of iron, 

 the co-existence of atomic movements becomes more 

 complicated, because light is transmitted, and, if the glass 

 be tinted, only light of a particular kind will filter through 

 the coloured medium. This co-existence of atomic move- 

 ments — comparable, maybe, to hornpipes, quicksteps, 

 polkas, quadrilles, and the like — is, for our purpose, 

 important to remember. The discoveries of histologists 

 suggest that all organic tissues — muscle, nerve, bone, and 

 so on — possess a structure of complex and definite form, 

 which may determine the direction and character of the 

 minute motion between their constituent atoms. 



A small quantity of musk may give off, in a still room, 

 a sufficient number of particles to sensibly affect the 

 olfactory nerves of any person entering the room, and yet 

 tbe total amount may be so minute that, after years, no 

 loss of weight in the original substance can be detected by 

 the most delicately constructed chemical bilance. What, 

 then, is the size of the individual particles, and can they 

 be larger than molecules '.'^They pass off in still air ; they 

 move ; what is the source of their motion '.' Why do they 

 pass away ? Observation is certain, but its interpretation 

 introduces uncertainty in proportion to the extent to 



* " The D.vnamics of Life." Bv Sir William Gower, F.K.S. 



