198 THE AMERICAN MONTHLY [September, 



when medico-legal offices became hereditary and corrupt, and remained 

 so until the French Revolution. Since 1803 France has required of her 

 medical experts, who, by the way, are appointed by the court, and not 

 as in this country retained by counsel, to be graduates in medicine and 

 also to pass a rigid examination on medical jurisprudence, in which 

 study they are presumed to have had special training. 



No direct application of the microscope to questions of law or of legal 

 medicine was made until about 1835, since which time it has been used 

 repeatedly in convicting the guilty and acquitting the innocent. No 

 longer are we obliged to resort to expedients taught by Albertus in 

 1726, such as that the victim's wounds would open and bleed afresh in 

 the presence of the murderer, or the time-honored custom of watching 

 die effect upon a suspected criminal as he touched the dead body of his 

 supposed victim — the latter test having been used until well into the 

 present century. 



As the greatest advances made in placing medicine as a science on a 

 proper foundation date from the application of the microscope to phys- 

 iological investigations, it is not strange we should find it at the pres- 

 ent time occupying a large and important field in medico-legal research. 

 At first, the microscope in its legal relations was confined to a few 

 questions in criminal law. With the improvements in modern lenses, 

 with the new and perfected means of determining minute measure- 

 ments, with the adaptation of the spectroscope and other accessories, 

 it has assumed such importance in both criminal and civil law as to 

 justify the coining of the term, Forensic Microscopy. Although the 

 microscope has for a number of years played an important part in many 

 noted criminal cases, its proper relation to law, and especially to med- 

 ical jurisprudence, is little understood. By many its powers are over- 

 estimated, while others underrate its value, or even cast aside as worth- 

 less all testimony relating to the results obtained through its use. 



It is an unfortunate though existing condition which permits 

 a person to testify as an expert in branches where he has but little 

 more knowledge than his hearers. Partly from this cause discredit has 

 been thrown upon the whole field of expert testimony in this country. 

 Physicians as a class are noted for never agreeing with one another, 

 especially when called upon to testify as witnesses. It is proverbial that 

 an equal number of medical experts may be obtained to express them- 

 selves on opposing sides. This, however, relates purely to their 

 opinions or their respective interpretation of facts. Such disagreement 

 is not confined to the medical profession, but invades all branches of 

 expert testimony- In cases involving questions of mechanics and 

 physics it is of frequent occurrence for expert machinists, electricians, 

 and others, to express exactly opposite opinions, and a notable example 

 of this may be found in the voluminous testimony recently taken in the 

 State of New York on the question of executing criminals by elec- 

 tricity. 



Where, however, two or more persons, expert in the use of the 

 microscope, are called upon to testify, there should be no disagreement 

 as to the results of any examination they may make. Thus, for exam- 

 ple, in the examination of a stain, if blood corpuscles are found, that 

 should be determined equally well by each. If measured, their meas- 

 urements should correspond exactly. There should be no difference on 



