372 THE POPULAR SCIENCE MONTHLY. 



undivided, ability to hear sounds at a longer range grows some- 

 what. Noise acts as an irritant in these cases instead of aiding as 

 in deafness due to disease. 



With speech and speech-reading attained, and perhaps the 

 happy addition of some perception of sound, the deaf need 

 not be thrown together as a class distinct from others. They 

 may and do receive instruction in common with their hearing 

 friends, attending leading schools and entering professional du- 

 ties side by side with them. Such persons have been charged 

 with an unwillingness to associate with the other deaf. Lack of 

 interest in their welfare we do not believe possible, but a prefer- 

 ence for the companionship of the hearing proves the existence 

 of a satisfying method of communication. All are easily influ- 

 enced by surroundings, and if deprived of any particular sense, 

 especially so. The deaf need every advantage possible, and not 

 the least of them should be adjudged daily intercourse with the 

 most evenly balanced characters, persons possessing a normal de- 

 velopment of all the senses. 







LOGICAL METHOD IN BIOLOGY. 



By FEANK CEAMER. 



THE logical processes involved in scientific reasoning are the 

 same in kind as those used in the everyday life of the masses. 

 The difference between the two lies in the clearer recognition of 

 the processes and their importance in the scientific field. There 

 is nothing like exactness in the applied logic of everyday life, and 

 the reasoning of science is superior to the " common sense " of 

 mankind only in being more exact. In science the comparatively 

 little work that survives and does not have to be done over and 

 over owes its superiority to this same exactness. Science has no 

 peculiar method of its own either of discovering facts or of treat- 

 ing them. 



Scientific students spend little time on the consideration of 

 logical processes, because the mind follows them instinctively ; and 

 the study of them, for practical purposes, seems to be superfluous. 

 But apart from the fact that they present a set of phenomena as 

 worthy of scientific treatment as the phenomena of light or of the 

 molluscan nervous system, it is important to consider them because 

 of their direct bearing on every department of science. Even the 

 best established sciences have reached their present states by suc- 

 cessive approximations toward exactness, by the gradual elimina- 

 tion of errors of both fact and method ; and even the novice knows 

 that the degree of confidence placed in the statements of fact of a 



