THE AMERICAN LAW REGISTER. OCTOBER 1876. MICROSCOPICAL EXAMINATION OF BLOOD IN ITS RELATION TO CRIMINAL TRIALS. CAN the red blood corpuscles of other animals be distinguished from those of man, so as to warrant a certain conclusion in those criminal cases in which the question becomes of value in deciding the guilt or innocence of the accused? It has hitherto been a disputed point, whether human blood could be distinguished from other mammalian blood by any means whatever. The object of this article is to show that this may be determined by measurement, based upon the observation that the corpuscles of human blood, in the aggregate, are larger than those of any other mammal. Blood itself can be told from other substances by other methods, which serve as a resource in those cases where the corpuscular forms have been destroyed; but by this means alone can the different kinds of blood be recognised. Dr. Joseph G. Richardson, in his work on Medical Microscopy, quotes the following case, showing the value of microscopic examination, not only in the detection of blood stains, but of other suspected matters, which may chance to have a bearing upon the detection of crime: "The trial occurred at Norwich, England, about the year 1850, under the following circumstances: A female child, nine years of age, was found lying on the ground in a small plantation, quite dead from a wound in the throat. Suspicion fell upon the mother VOL. XXIV.—71 (561) of the girl, who, upon being taken into custody, behaved with the utmost coolness and admitted having taken her child to the plantation where the body was found, whence the child was lost while going in quest of flowers. There was found in the woman's possession a large knife, which was submitted to a careful examination; nothing was found upon it, however, with the exception of a few pieces of hair adhering to the handle, so small as to be scarcely visible. The examination being conducted in the presence of the prisoner, and the officer remarking: Here is a bit of fur or hair on the handle of your knife,' the woman replied Yes, I dare say there is, and very likely some stains of blood, for as I came home I found a rabbit caught in a snare and cut his throat with the knife.' "The knife was sent to London, and with the particles of hair submitted to a microscopic examination. No trace of blood could at first be detected upon the weapon, which appeared to have been washed; but upon separating the horn handle from the shaft, it was found that a fluid had penetrated into the socket which was found to be blood, certainly not the blood of a rabbit, but bearing a resemblance to that of a human body. This hair was "The hair was then submitted to examination. found by the microscopist to be that of a squirrel. Now round the neck of the child at the time of the murder there was a tippet of squirrel's fur. This strong circumstantial evidence was deemed by the jury sufficient to convict the prisoner, and while waiting execution she confessed her crime." Had the woman not convicted herself, in her statement to the officer, and the blood on the shaft of the knife been the only evidence of guilt, perhaps this would not have warranted a conviction, even if it could have been shown to be human blood, as it might have been of old date and the result of accident; but had human blood been found upon the blade, which could not have been fully accounted for in some other way, it would seem to be pretty conclusive evidence. It will be remembered, in the recent case of Rubenstein, in New York, the defence claimed that the blood found on the prisoner's clothes was hen's blood. This blood is easy to be distinguished from human blood by the form of the corpuscles, but as Prof. Eaton, who testified in the case, did not claim to be able to distinguish the blood actually found from some other kinds of mammalian blood (of the dog, for illustration), had the criminal been wise enough, he might have been able to cheat the gallows, perhaps, without having recourse, as he did, to suicide for that purpose. But can human blood under any circumstances be clearly distinguished from that of other mammals which resemble it in formthe blood of the dog, for instance? Dr. Richardson claims that it can be certainly known from that of the ox, sheep or pig, but does not speak of the dog. In a recent work by M. Naquet, "Professor to the Faculty of Medicine of Paris," entitled "Legal Chemistry a Guide to the Detection of Poisons, Examination of Stains," &c., the following statement occurs: "When they" (the blood-stains) "are tolerably recent they may be detected by examining the moistened stained cloth directly under the microscope; a discrimination between animal and numan blood is then possible." In regard to the recognition of blood stains of long standing, "M. M. Briand Choude Claubry" (Manuel complet de Médecine Légale, Paris, 1852, page 789), declares that " however great may be the age of the spots, microscopical examination will nevertheless reveal the blood globules; those on which M. Robin made his experiments dated back from eight to twelve years." On the other hand, Dr. Woodward, of Washington, D. C., in commenting upon Dr. Richardson's paper, "upon the possibility of distinguishing the blood of man from that of the ox,' &c., in a communication published in the "London Microscopical Journal,” of February 1875, says, "there are certain mammals, among them the dog, whose red blood corpuscles are so nearly identical in size with those of human blood that they cannot be distinguished by any power of the microscope, even in fresh blood, much less in dried stains." Having been myself engaged for some time past, in microscopic and chemical investigations, several of which have brought me as a witness in cases before the courts, and also for a number of months having made the distinguishing between human and other mammalian blood, as well as that of other red-blooded animals, both fresh and in dried stains upon various materials, a careful study, I propose to give the results of these investigations in a journal of the legal profession, to which profession they seem practically to belong, and leave it to them and the scientific world generally to pronounce judgment in the case. PLATE I. Where the forms of the blood corpuscles differ from those of man, as would have been the fact in Rubenstein's case, had the blood found on his garments been, as he alleged, hen's blood, the question would present no other difficulty than the actual recognition and showing of the forms of the corpuscles, without regard to their size; but in those cases which depend upon differences of C Tables of Red Blood Corpuscles of Man and Dog, magnified 1275 diameters. |