4 6o THE POPULAR SCIENCE MONTHLY. 



these various well-defined vital phenomena are dependent, if we can 

 succeed in establishing their direct relation, their immediate continuity 

 with the rest of the world, then we cannot possibly be far from having 

 reached the solution of the first phase of our problem. 



There can be no manner of doubt that the secrets of the origin of 

 vitality, and of the rise of organization, must all lie encompassed in 

 these most unsophisticated dots of living material. What more entic- 

 ing prospect for scientific investigation could be found ? The nature of 

 vital phenomena, if not disclosed even here in its plainest mode of 

 manifestation, must ever remain incomprehensible. It is the fundament- 

 al truth of living reality, in all its native force, which in this unorgan- 

 ized and quickened matter appeals to our understanding, and it needs 

 but candor, simplichvy, and courage, to become initiated into the mys- 

 tery of vitality. Let us, then, endeavor to cast away the incumbrance 

 of so much foreknowledge, misleading as it has proved. If at all at- 

 tainable, here it is, with our diminutive specimens of vitality, that true 

 insight is to be gained. At any rate, we cannot leave the inquiry till 

 we know, or till we have become fully convinced, that vital phenomena, 

 even in their elements, are impervious to human knowledge. 



Having for the last four years concentrated his whole attention on 

 the manifestations of primitive life, and reached results which he deems 

 important, the present writer, in a succeeding and fuller article, will 

 attempt to convey to the general reader some idea of what he has 

 gained by these studies. 



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COMPOSITE PORTRAITS. 1 



By FRANCIS GALTON, F. K. S. 



I SUBMIT to the Anthropological Institute my first results in carry- 

 ing out a process that I suggested last August in my Presidential 

 Address to the Anthropological Subsection of the British Association 

 at Plymouth, in the following words: 



" Having obtained drawings or photographs of several persons alike in most 

 respects, but differing in minor details, what sure method is there of extracting 

 the typical characteristics from them ? I may mention a plan which had occurred 

 both to Mr. Herbert Spencer and myself, the principle of which is to superim- 

 pose optically the various drawings and to accept the aggregate result. Mr. 

 Spencer suggested to me in conversation that the drawings reduced to the same 

 scale might be traced on separate pieces of transparent paper and secured one 

 upon another, and then held between the eye and the light. I have attempted 

 this with some success. My own idea was, to throw faint images of the several 

 portraits, in succession, upon the same sensitized photographic plate. I may add 

 that it is perfectly easy to superimpose optically two portraits by means of a 



1 Abstract of a paper read before the London Anthropological Institute, April 30, 

 1878. 



