MR. HERBERT SPENCER. 165 



that he has ventured to strain theories to an extent that no 

 actual observer would have, permitted himself to do, and 

 he has in many cases accepted, apparently without the 

 slightest misgiving, inferences very recently deduced by a 

 single observer only, the incorrectness of which would have 

 been immediately suspected by any one who had the advan- 

 tage of practical knowledge of the subject. 



Few enterprises are indeed more hazardous than that of 

 constructing a philosophy upon a basis of physiology. Such 

 philosophy, like the physiology upon which it rests, must 

 be liable to very striking change. But ought philosophical 

 principles to be continually shifting with every change in 

 physiological doctrine? And yet it is not easy to see 

 how a philosophy, based upon physiology, is to stand 

 when the physiology upon which it is made to rest shall 

 have been proved to be unsound, and shown to be fit only 

 to be cast away as resting upon errors of observation and 

 erroneous inferences. 



Many of Mr. Herbert Spencer's conclusions are un- 

 questionably based upon views of physiological action 

 which must be given up, and unfortunately much of the 

 physiology taught in his volumes is already behind the time, 

 and requires to be modified in important particulars. I 

 shall venture to draw the reader's attention to one or two 

 instances, out of many, that might be cited. 



Concerning the action of membranes, Mr. Herbert 

 Spencer revives notions that were abandoned many years 

 ago, and gravely supports old theories which are not, and 

 indeed never were, tenable. Speaking of colloid bodies, 

 and the alterations effected in them by osmose, he remarks, 

 that " very many of the conspicuous changes of form under- 



