Blood stains often play an important part in medico-legal cases. Much of the existing literature upon this subject has outlived its usefulness, and the medico-legal expert or the lawyer that bases his conclusions on such is liable to err. An important contribution to this subject has recently appeared—" Comparative Studies of Mammalian Blood; with special reference to the Microscopical Diagnosis of Blood Stains in Criminal Cases," by Dr. Henry F. Formad, of Philadelphia.
Is it human blood? is a question that sometimes involves serious consequences. In determining this question in regard to blood stains, it should be remembered that blood stains are best seen by artificial light. The liquids used for remoistening and disintegrating dried clots of blood must be of such composition that no harm will be done to the corpuscles. If one wish simply to determine the presence of blood corpuscles, then water, oil, alcohol, glycerine, etc., may