53 8 THE POPULAR SCIENCE MONTHLY. 



THE PKEDICTTON OF NATUKAL PHENOMENA * 



By Dr. ARNOLD SCHAFFT. 



A LTHOUGH those times have gone by which oracles and sooth- 

 -*--*- sayers played an important part, yet even at the present day 

 prophets are to be found almost everywhere. We will not speak here 

 of politicians, of those that predict peace and war, nor of speculators 

 and the so-called reformers, with their predictions in the domain of 

 commerce and industry. We shall confine ourselves to the discussion 

 of natural phenomena not alone to those that are grand and strik- 

 ing, but shall in preference turn to the common occurrences of every- 

 day life. 



"What weather are we to expect within the next few days?" 

 Only put the question, and a hundred answers will be volunteered. 

 The curing of all diseases is often predicted by quacks and patent- 

 medicine men with a degree of assurance scarcely to be believed. 

 " This remedy never fails," is the superfluous winding-up of many an 

 advertisement of their nostrums, and thousands of credulous people 

 daily fill the pockets of these charlatans. 



A considerable number of those persons who do not permit them- 

 selves to be thus caught err in the opposite direction that is to say, 

 they regard all predictions with mistrust. For instance, they attach 

 but little importance to any of the attainments of medical science ; 

 they doubt the usefulness of meteorological stations, etc. And yet 

 even skeptics like these must acknowledge that nnmerous astronom- 

 ical predictions come true with a degree of precision and accuracy 

 that must astonish every one. 



What prophecies, then, are to be believed? The predictions of 

 science ? Alas ! how many supposed scientific predictions have proved 

 to be mere delusions ! The word " science " will not answer in this 

 connection. Is there, then, no standard by which the value of pre- 

 dictions of natural phenomena may be gauged or measured ? 



A standard exists, and may be determined by an acquaintance with 

 the elements of inductive logic, and with the most important teach- 

 ings of natural science. Considering the wide-spread interest that 

 attaches to this question, it will be worth while to study the subject a 

 little more closely. 



Almost every prediction requires some statement admitted to be 

 universally valid, from which it may be deduced. If one desires to 

 know how probable a prediction is, it will be well to test it by the 

 following questions : Does the prediction rest on simple enumeration ? 



* Translated and condensed from Virchow and Holtzendorffer's " Sammlung gemein- 

 verstandlicher wissenschaftlicher Vortrage " (" Collection of Popular Scientific Lect- 

 ures "). 



