SCIENCE IN ANTIQUITY. 17 



of elasticity of gases would be a mere toy, instead of having 

 led to the construction of steam - engines, steamships, and 

 railways. Many of the substances familiar to us were 

 unknown to the ancients. 



VIII. The POLITICAL ECONOMY of the old world was 

 limited to the development of agriculture (mostly by slave- 

 labour). The best and most practical minds, Xenophon and 

 Cato, discountenanced and despised industry and commerce. 

 Capital, where it existed, was either applied to usury, or 

 dissolved in the gratification of sensual enjoyment ; so that 

 industry, commerce, capital, the three greatest springs of 

 social progress, were practically non-existent. 



When we bear in mind that tools are necessary to 

 construct machines, and machines are necessary to probe 

 the earth, and that in addition to the immense drawbacks 

 just enumerated, the ancients had no machinery to speak 

 of and scarcely any tools, we can at once understand what 

 little progress could be made, how slowly that little progress 

 could be effected, and how easily it was arrested arrested, 

 that is, in its infancy by the ruthless invasion of the Bar- 

 barians and the break-up of the Roman rule. 



It is almost a truism to say that the underground re- 

 sources of the earth, the workshop, the Physicist's room, 

 and the Chemist's laboratory must of necessity be kept 

 in continual connection and INTERCOURSE with one another 

 in order that scientific progress may be effected. These 

 act and react upon one another just as much and in the 

 same manner as pure science and application of science 

 act and react upon each other. From those elements and 

 their reciprocal effects scientific evolution necessarily follows. 



Furthermore, and this is of equal importance, in order 

 that improvements should be fruitful and durable, supply 

 a multitude of wants, give enjoyable affluence to peoples, 

 and thus conduce to the establishment of social order and 

 social welfare, and hence to that intellectual maturity which 

 breeds science, there must exist INTERCOMMUNICATION 

 among nations ; more, the means of communication are 

 equally indispensable to conquer, and act upon, Nature- 

 Nature having, for our good, unequally distributed that 



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