Epidemics. 221 



instead of sinking into petrified organic remains, rising, like 

 " authors under difficulties," to be the lords of creation, or 

 chiel organic compounds, who, through selection, have 

 attained to a maximum of development. 



But let us halt for a moment, and learn from true records. 

 Mrs. Marcet, in the "History of Astronomy," issued by the 

 Society for the Promotion of Useful Knowledge, has indicated 

 that India, China, the Chaldees, and Egyptians had attained 

 to a very correct knowledge of the yearly cycle of 365 days. 

 Without entering into the fractional details, or the difficulties 

 which beset a very correct determination of time, it may 

 be said that they had great ability to indicate the time of 

 eclipses. It must be said that, with their defective methods 

 of determination, without the aid of very long observations in 

 the same individual, from great defects in the powers of 

 expression of any abstruse calculation, the accumulation of 

 knowledge and experience, sufficient to gain a correct know- 

 ledge of the precise working of the time-piece of Nature, 

 is next to impossible, if not so altogether. But if one man, 

 or many men in different regions of the earth, having a 

 special aptitude for observations of this kind, lived over 150 

 years of real active life, man would during that time, in a 

 good Eastern country, not only with the instruments he 

 used to guide his observations, get very proficient, and, by 

 dint of observations often repeated, correct the errors of his 

 own instruments ; but also, by a long succession of obser- 

 vations, he would, from long experience, be capable of 

 rectifying and harmonizing defects of an early period, and 

 so be enabled to elicit great general facts, as guiding-posts 

 for future generations, in clear and intelligible language, 

 without a hundred and two formularies, to correct the defects 

 of differential elements which must necessarily creep in, but 

 which, by a powerful synthetical and analytical process, over 

 short periods of time, can now weigh in the balances, 



