148 TRANSACTIONS OF THK IM-INOIS 



world, whether he lias an\' in his pocket or not ; also tliat we have some 

 sort of weatlier nearl\- cver\- day. And the few thincrs we do not know 

 about any of these subjects, by a stupendous excess of courtesy to our- 

 selves and to our own wisdom, we call our science of this, that, or the 

 other ; and so, among the rest, we have the science of meteorology. 



But whatever scientific knowledge of meteorology we have, we have, of 

 course, derived either from our knowledge of signs, or of periods, or of causes. 



Our knowledge of signs of changes in the weather is very meagre ; 

 that of fixed recurrent periods still less; and that of causes least of all. 

 The difference between these is this : Real causes never fail of their 

 results, nor real periods of their return — like day and night, summer and 

 winter — while true and real signs may sometimes fail, even when w^e least 

 e.xpect them to do so, and thus mislead even the wisest observers. In 

 niedicine, signs are called symptoms, and we all know that the best of doc- 

 tors sometimes miss the mark, and kill the patient instead of the disease. 



It may be of little practical, immediate interest to horticulturists, in 

 theij money-making schemes, to discuss either the periods or the causes 

 of the changes of the weather ; still we should never forget that the intel- 

 ligent hortitultural man is greater than any of his products, and what- 

 ever stimulates him to renewed observation and thought, is the most val- 

 uable of all his products. Besides, I think that this Society, by admitting 

 such discussions, has gained in dignity, character, reputation, and power 

 for good, both at home and abroad. Its readiness to contribute its mite, 

 however small, to the general progress of human knowledge, widens its 

 esteem and influence among men. 



On former public occasions I have spoken of the signs of the changes 

 in the weather ; and among these of the effect of wide regions of hot, 

 dry earth in the late autumn, in determining the character of oiu" winters 

 and springs. 



This sign, though in itself a powerful cause, in so far as it really 

 exists, is so liable to be over-estimated as to its real breadth, and is so 

 often interfered with and held in check by other powerful causes, as to 

 sink down to the level of a mere sign, which sometimes fails, though it 

 generally succeeds. 



I propose at present to say a few words more particularly upon the 

 causes of climatic changes and their resultant periods. 



If, in view of the present controversies extant on meteorology, 

 originating, in part, in this Society, I go back, in this paper, further 

 toward the final analysis of being itself, and the axioms of all possible 

 science than would be appropriate to a mere spoken address, I trust my 

 most thoughtful hearers will in the end see and appreciate my reasons. 



In all possible physical sciences we have generically and primarily 

 but two simple things to deal with : First, matter, or that which is capable 

 of receiving and manifesting to our senses form, motion, color, tempera- 

 ture, and its inertia or inherent resistance to change, either of form or 

 motion ; and, second, force, or that universal cause which produces all 

 the changes in the forms, motions, colors, or temperature of matter, and 

 overcomes its innate inertia whenever or wherever it is overcome at all. 



