said my answer was wrong. In answer to the other questions, I told them I did not know. The committee, being satisfied that I did not know and had answered according to the facts, assured me my answers were correct, and recommended my admission to the bar." It matters not whether this story is fiction or veritable history, it illustrates that honesty and truth can always be vindicated by answering as the facts require, and that is far more essential in the administration of justice than to guess at things not known. The lawyer is sometimes, not without cause, accused of splitting hairs in pro fessional matters. Cannot the medical ex pert also sometimes be justly charged with the same offense, especially when he testi fies to the revelations of the microscope? It is asserted that human blood can be dis tinguished from that of some of the lower mammalia, but it seems to be a mooted question whether it can be distinguished from that of the dog or ape. The dif ference in the size and form of the micro scopic red corpuscles of the blood seems to be the distinguishing test. Schmidt finds the diameter of human blood corpuscles to be -§.2*8$ part of an inch, and that of the dog ^g^g part of an inch. Other observers vary these figures somewhat, but the pro portion remains substantially the same. If this infinitesimal difference in the size is the distinguishing feature, is it not practically impossible for any observer, however skilled in the use of the microscope and the micrometer, to accurately measure and cor rectly inform court and jury which is human blood and which is not? It 1s very unusual if not impossible for different surveyors of skill and experience, starting from the same meander post, to run out the meander line of a dozen courses and distances around a lake, half a mile in diameter, with the same results. Often the variation amounts to sev eral feet, and sometimes to several rods. If it is impracticable to measure such a lake with accuracy, how much more difficult must
it be to measure a blood corpuscle. Is it safe to convict and execute men upon such evi dence? But little reliance should be placed upon such testimony in the administration of justice, especially when we consider the variation in the power of vision, whether the observer is myopic or hyperopic, whether he sees with the acute clearness of youth, the moderation of middle life, or the dim ness of age; to say nothing of the condi tions of the light and air. How learned, how careful, how conservative and how candid, should be the expert witness, in discovering the secrets of chemistry and histology, and in declaring them on the witness stand! The ordinary and the most effective means of exposing the ignorance, of detecting the mistakes, and of demonstrating the perjury of an incompetent, careless or corrupt wit ness is by cross-examination. Psychologically there is a great difference between witnesses, which is almost univer sally overlooked by the casual observer. Some witnesses are utterly devoid of the sense of the obligation of veracity; some will tell a falsehood as if they were telling the truth; others will tell the truth as if they were telling a falsehood. A large class of honest witnesses are utterly unable to discriminate between a conception of memory and a conception of imagination; between cognition and feeling; between fact and fiction; between hearsay and personal perception; between the suggestion of sym pathy or prejudice and the suggestion of an actual fact or an existing truth; between the impression of a dream and the impres sion of an event. Because witnesses are unable to distinguish between the ideal and the real, things imagined are often uncon sciously sworn to as facts remembered; what others have said, as matters actually seen; what is hoped for, as an actual fact; what is hated, as hateful; what is loved, as lovely; regardless of the real truth or ex isting attributes. The expert witness is not always exempt from the frailties of human
