TECHNOLOGY
Chemists in Court Chemists are involved with many phases of the law — crime detection, food and d rug regulations, patents I N D I A N A P O L I S , I N D . - C h e m i s t s may b e called upon to testify in legal cases ranging from murder to patent suits. T h e r e is no phase of chemistry which might n o t be used in adjudicating a case, according to C. W. Maehlberger, C r i m e Detection Laboratory, Michigan D e p a r t m e n t of Health. Muehlberger was one of five speakers at the Chemistry and t h e L a w Symposium at the ACS Indiana Section recently. Unlike civil cases in which the judge merely decides for the side showing t h e greatest preponderance of evidence in its favor, criminal cases require proof beyond a reasonable doubt with b u r d e n of proof resting with the prosecutor. Great care must therefore b e taken in introducing chemical evidence into criminal cases. It is necessary to b e n d over backward to see that samples analyzed for evidence are free from contamination, have not heen altered in any -way, and are actually the samples they are supposed to b e . Chemical analysis is useful in showing w h e t h e r a substance is present or absent, and if present what its concentration is. It can also show whether substances have or could have a common origin, and sometimes, what form t h e substance h a d . In a case of arsenic poisoning, analysis can show whether lead arsenate, sodium arsenite, or Paris green was the original form of poison. Route of entry into the body can also be shown in some cases. In a case in which it -was alleged that a cyanide-poisoned man inhaled hydrogen cyanide accidentally w h i l e u s i n g the gas as a fumigant, post mortem examination showed that the stomach content was rich in cyanide and the tissues were not, so it was evident that the victim h a d received cyanide b y mouth, not by inhalation. Time factors may also be determined by laboratory techniques. Arsenic administered as a slow poison forms deposits in the hair and nails. I n a case in France hair containing arsenic w a s treated to make the arsenic radioactive and it was then possible t o check the location of the arsenic. K n o w i n g the approximate rate of growth of hair enabled investigators to d e t e r m i n e how long the victim had b e e n receiving poison. Most poisonings are accidental and possibilities of exposure through medication or industrial employment should b e exhausted before criminal intent is 5046
suspected. Muehlberg&r cited a case in which a man suspected his wife of poisoning him, and me
