XXIV INTRODUCTION. 



takes nothing for granted, which, in reading a well- 

 arranged and instructive series of illustrations, argu- 

 mentatively apphed, is continually asking, '" Quo 

 tramite tendis ?" And when, at length, the goal is 

 discovered to which Mr. ElHs is conducting it — when 

 he briefly concludes, " Against the evils arising from 

 such a vitiated atmosphere, the plan of Mr. Ward 

 provides effectual protection, as the success of his 

 establishment amply demonstrates," then this little 

 jury pronounces instantly a verdict of " Not Proven." 

 Mr. Ellis seems scarcely aware of the extreme diffi- 

 culty of maintaining any essential difference between 

 the component parts of atmospheric air on the inter- 

 nal or external side of any given partition. He seems 

 scarcely aware that Mr. Ward's estabhshment — the 

 success of which he justly considers beyond dispute — 

 communicates with the surrounding murky and foul 

 atmosphere by means of a glass door, of the usual 

 construction — a door opened by every visitor on 

 entering this paradise — 



"Exiguus spatio, variis sed fertilis herbis :"* 



And again by every visitor on returning ; and that 

 these openings are much too frequent to allow the 

 possibility of maintaining any difference in the pro- 

 portions of the gases composing the internal and ex- 

 ternal air, even supposing that the air would not so far 

 elude Mr. Ward's care, were the door rigidly kept shut, 

 as not to insinuate itself through the ten thousand 



* This line, from the Moretum of Virgil, is over the door. 



