io8 POPULAR SCIENCE MONTHLY. 



born, ill-bred constitution come so to be, and hence to break down 

 so easily. Certainly, the weak, easily breaking strains must have 

 their origin and growth just as definitely as the more enduring ones, 

 and if we can get an accurate notion of such origin and the con- 

 ditions of subsequent growth, it seems probable that useful knowl- 

 edge will thus be attained. 



With this object in view an investigation was undertaken which 

 should cover the life histories of a series of families with sufficient 

 detail and extension to warrant at least tentative conclusions as well 

 as also to indicate probable lines for future work. So far as possible, 

 inquiries were pushed along collateral as well as direct lines of an- 

 cestry; and not only ill health but common habits and experiences 

 were, so far as possible, given the consideration strictly their due. 

 In every way the attempt was made to properly estimate the factors 

 appertaining to the more intimate personal life as well as those that 

 were more obvious and impersonal. Often, however, the completed 

 record proved to be more or less broken; more often still, important 

 items the most important of all, in fact could only be obtained 

 under promise of absolute secrecy as to future use. So, as matters of 

 absolute science, the following conclusions must stand chiefly as chal- 

 lenges for future confirmation or change. But, so far as they can 

 be allowed to go, they may be accepted as pretty thoroughly based in 

 ascertained fact and legitimate generalization. 



The very first conclusion, so far as the natural history of the steps 

 toward insanity is concerned, is that the weak constitutional strands 

 and tendencies have their beginnings in those ancestral marriages 

 which, chiefly for educational reasons, I have chosen to call " unphysi- 

 ological." * By an unphysiological marriage one need not mean a 

 marriage between people obviously deformed or imbecile or insane, 

 or otherwise permanently unfitted, but rather between people who 

 are found to be not well adapted to each other in some important 

 sense. Thus, too great physical disproportion ; too great disparity of 

 age, or of temperament, or of family or of natural tendencies; or, on 

 the other hand, too near a sameness, either through consanguinity or 

 other sources; or too fixed constitutional characteristics; or even too 

 great differences of education, religion, taste, or ambition. In fact, 

 it seems probable that anything and everything which difficultly 

 amalgamates in marriage, and as surely fails to blend in progeny, 

 may be considered as unphysiological in this connection. As I have 

 said elsewhere: "The parties entering into such an unphysiological 

 marriage may both be normal individually, but yet not physiologi- 

 cally marriageable, because they are either too distantly or too nearly, 

 or in fact too unphysiologically, related, either physically or psychic- 



* See New York Medical Journal for August 14, 1897. 



