In the event of the first named powerful poison--the one that defies detection--there is no odor or other discernible indication of any nature. When scientifically administered the fatal dose is less than one billionth the weight of an ordinary human body. Thus, to trace it, the autopsy doctors would have to find, separate or segregate a billionth bit of the mass under observation. The body completely absorbs the fatal chemical and so--. This poison has its uses but is rare and impossible to obtain even by most chemists. There are few dispensing druggists who have scales sensitive enough to weigh the dosage of the chemical. Even for doctors to obtain it is an undertaking involving considerable red tape. But it has been used by murderers--scientific murderers. Circumstances in these cases have proven that the murderer possessed the drug and had a motive to use it. Confession has followed circumstantial evidence in some cases and in others conviction has been obtained on expert testimony backed by positive circumstantial conditions, such as the presence of the corpse and proof of the ante-mortem possession of the fatal drug by the suspected murderer. A fiction story of the football grid, some years ago, involved the use of a solution to produce a fatal gas under conditions of bodily heat produced by violent exercise. This was authentic so far as action and effects were concerned. In the football story the victim's sweater was soaked in a deadly solution. Under the heat of the exercise during the football game the victim's body generated the gas which he inhaled. The gas stimulated his heart action to the point where a blood vessel was ruptured causing death. The actual case from which this fiction story was borrowed involved a man, a wife, and the wife's clandestine violinist lover. The wife knitted the sweater for her admirer. Her husband dipped it in chemical solution and dried it while his wife was absent. When she returned she expressed the sweater to her admirer. He wore it under his shirt. His body heat produced the gas which was inhaled by the violinist in sufficient quantities to cause death. The hypodermic needle is a weapon of death which has caused autopsy physicians trouble since its invention. Murder by the hypodermic needle, no doubt, would escape detection often enough were it not for circumstances. Such circumstances of death are ever in the mind of autopsy doctors. Where evidence warrants it corpses are subjected to microscopic and meticulous search to locate a hypodermic puncture. And they can be located even when hidden back of an eyelid as was the case in one instance, that of an infant. The suspected murderer, in this case, a colored mother, died in an insane asylum.