THE PRESIDENT'S ADDRESS. 83 



in need of guidance than the agriculturists of other countries where 

 more advanced systems of husbandry are in vogue, even though their 

 systems have little pretence to a scientific foundation. But now, 

 when the necessity and value of a different mode of farming are fully 

 felt and acknowledged, science has come to the aid of agriculture ; 

 and principles, developed and made manifest by chemical research, 

 have been brought within the husbandman's reach. 



The knowledge of what food plants require in order to attain the 

 fullest maturity, and consequently what manures are best fitted to 

 an exhausted soil, or to a soil incapable in its natural composition of 

 affording that nutriment, is one of those benefits which agriculture 

 owes to purely scientific research, and which makes the name of 

 Liebig a household word with every farmer capable of appreciating 

 the advantages so derived. 



I am more at home in referring to the. acknowledgments which are 

 due for the assistance rendered by physical science and observation 

 in Judicial investigations. The past year has afforded one very 

 remarkable instance of its invaluable service in bringing to justice 

 a criminal, whose slow but surely fatal operations on his victim's 

 life would never have been demonstrated but for the aid of chemical 

 analysis. There was a Nemesis in this. The murderer, who availed 

 himself of the discoveries of chemistry — subtilely, and as he hoped so* 

 as to defy detection — to inflict death, was discovered and subjected 

 to his well-deserved fate, through the instrumentality of that very 

 branch of science which he had so grossly abused. 



It concerns us all that physical science should unite with juris- 

 prudence in increasing our protection against crime, by affording 

 means, unthought-of before its aid was invoked, for the detection of 

 the guilty. The number of criminals would be greatly reduced if there 

 was an assured certainty that crime would be followed by detection, 

 as well as detection by punishment. As one means of securing this I 

 have observed the practice adopted in England, and I believe also 

 in some other parts of Europe, of taking Photographic likenesses of 

 persons charged with crime, and thus depriving them of the chances 

 of escaping identification, which a change of name or of residence 

 might afford. The A. B. of London criminal notoriety may be ar- 

 rested in Liverpool and known there only as C. D. ■ all inquiries 

 respecting him under the alias may be wholly unavailing, but the 

 portrait transmitted from the police of the latter to that of the for- 

 mer city, removes the difficulty and puts the avenger of violated 

 aw on the right track. 



