314 Prof. Schow on the supposed changes in the 



certains the present limits for these beings, and the relations of 

 the temperature on these limits, may lead to conclusions con- 

 cerning the former climate ; and it is only to be regretted that 

 the geography of plants is still in its infancy, and that a geo- 

 gi^phy of animals hardly exists. 



Great care is likewise required in drawing conclusions from 

 the time of harvest in antiquity, which partly depended upon 

 varieties of corn, which we hardly will be able to ascertain, and 

 partly upon the tillage ; besides it is different in different years, 

 of which the mean time is to be taken. 



With respect to such phenomena as seem to depend upon 

 changes in the climate, such as the freezing of the sea, the 

 protrusion of ice from higher places, a great difference must 

 be made between that which is usual and that which is extra- 

 Ordinary ; and great allowance must be made for the weakness 

 of human memory, which recollects much better the exception 

 than the general rule of things. Similar uncertainty is found 

 with respect to the customs of the inhabitants, depending so 

 much upon the tribe which inhabits the country, their state of 

 culture, &C. &c. 



-Criticism must be applied in studying the authors from 

 which we draw our knowledge of the produce of former times. 

 The richest and best harvest will evidently be obtained from 

 writers on natural philosophy and natural history ; but histo- 

 rical and geographical writers are not to be neglected, and even 

 poets may furnish soine important facts. But of course the 

 greatest care and caution is here principally required. 



The author divides the historical time into two great pe- 

 riods, of which one, comprising all history until the time when 

 real meteorological observations began, is again subdivided in- 

 to two smaller periods, the one of which ends about the year 

 400 p. c w., and has its best authorities in the Greek and Ro- 

 man writers ; the other, which comprises the latter half of that 

 great period, has the Arabian writers, the chronicles of that 

 time, and the newer historians for its best authorities. 



I. Part of the I. period- Antiquity. 



It will be convenient to begin with Palestine, the Bible being 

 the oldest, or one of the oldest books ; and although great un- . 

 certainty exists about the determination of the plants which 



