SPECULATION IN SCIENCE. 741 



SPECULATION IN SCIENCE. 1 



By Pbojt. J. LAWRENCE SMITH. 



I NOW pass to the second part of my discourse. It is in reference 

 to the methods of modern science the caution to be observed in 

 pursuing it, if we do not wish to pervert its end by too confident as- 

 sertions and deductions. 



It is a very common attempt, nowadays, for scientists to transcend 

 the limits of their legitimate studies, and in doing this they run into 

 speculations apparently the most unphilosophical, wild, and absurd ; 

 quitting the true basis of inductive philosophy, and building up the 

 most curious theories on little else than assertion ; speculating upon 

 the merest analogy ; adopting the curious views of some metaphysi- 

 cians, as Edward von Hartmann ; striving to work out speculative 

 results by the inductive method of natural science. 



And such an example as this is of great value to the reflective 

 mind, teaching caution, and demonstrating the fact that, while the 

 rules by which we are guided in scientific research are far in advance 

 of those of ancient days, we must not conclude that they are perfect 

 by any means. In our modern method of investigation how many 

 conspicuous examples of deception we have had in pursuing even the 

 best method of investigation ! Take, for instance, the science of ge- 

 ology, from the time of Werner to the present day. While we always 

 thought we had the true interpretation of the structural phenomena 

 of the globe, as we progressed from year to year, yet how vastly dif- 

 ferent are our interpretations of the present day from what they were 

 in the time of Werner ! In chemistry, the same thing is true. How 

 clearly were all things explained to the chemist of the last century by 

 Phlogiston, which, in the present century, receive no credence, and 

 chemical phenomena are now viewed in an entirely different light ! 



Lavoisier, in the latter part of the last century, elucidated the phe- 

 nomena of respiration and the production of animal heat by one of the 

 most beautiful theories, based, to all appearances, upon well-observed 

 facts ; yet, at the present day, more delicate observations, and the 

 discovery of the want of balance between the inhaled oxygen and ex- 

 haled carbonic acid, subverted that beautiful theory, and we are left 

 entirely without one. It is true we have collated a number of facts 

 in regard to respiration, molecular changes in the tissues, etc., all of 

 which are recognized as having something to do with animal heat ; 

 still it is acknowledged that we are incapable of giving any concrete 

 expression to the phenomena of respiration and animal heat as La- 

 voisier did eighty or ninety years ago. 



1 Abstract of the address before the American Association for the Advancement of 

 Science, at its late meeting in Portland, Me., by the retiring president. 



