THE MICROSCOPE. 157 



SOME EXPERT TESTIMONY. 



BY C. H. STOWELL. 



JUST the moment that any person accepts a position of public 

 trust he exposes himself to honest criticism, and should he 

 come forward as an expert in any particular line of.work, then he 

 must expect to be carefully reviewed. It is a fact that a jury of 

 twelve men has no more idea what constitutes expert testimony than 

 a mule has as to what constitutes real genius. When the question is 

 one that concerns the value of a kicking horse or a spring lamb, 

 then the average criminal juryman appears at his best, but when 

 science is brought before him, that side of the case is most likely 

 to succeed which can bring to bear the best oratory and the greatest 

 number of witnesses. But this is neither here nor there. The 

 question is: "Can human blood be told from that of the dog?" 



In a recent case on trial at Wellsboro, Pa., Dr. Thad. S. Up de 

 Graff, of Elmira, N. Y., swore very positively on this point. The 

 newspapers give Dr. Up de Graff the credit of convicting the 

 prisoner. It is not the proper place here to determine whether the 

 prisoner was guilty or not; it is in the precincts of this journal, how- 

 ever, to determine whether the expert testimony was accord- 

 ing to facts. Dr. Up de Graff was given some of the stained 

 clothing to examine, and by processes entirely unknown to the 

 writer (according to all accounts seen), by decantations, washings^ 

 etc., some corpuscles were procured and measured. Dr. Up de Graff 

 positively testified that this was human blood and not dog's blood. 

 When asked if he was the only one who could tell this, he replied 

 that "there were but four men in the world who could tell human 

 blood from dog's blood;" and, of course, he was one of them. 

 When asked why he could do so much better than others, the reply 

 was "on account of the superior character of his glasses, and that 

 his microscope cost sixteen hundred dollars." The testimony of Dr. 

 Up de Graff makes him give a positive size to the human red blood 

 corpuscle. What do standard writers say on this subject? 

 Gulliver says they are the ^gW °f an inch. 

 Flint says they are the 3 ^Vo of an inch. 

 Dalton says they are the ^yjT to T0V0 °f an inch. 

 Richardson says they are the ^wrs °^ an inch- 

 Woodward says they are the 3() \ i of an inch. 



