Forensic samples

Forensic samples - preliminary studies used in forensic practice in the autopsy and investigation of evidence.
In section table holds the following forensic samples.
Test Ransa on arsenic. Stomach content is placed in a flask, add hydrochloric acid, it is put a copper plate and heat up. In the presence of arsenic copper plate is covered with gray bloom; then the plate is washed, placed in the tube and heat - on the tube wall appears white bloom arsenous anhydride.
Test Ransa on mercury put the same as the test for arsenic, but the copper plate placed in the tube iodine crystals. When heated on the tube wall in the presence of mercury appears red plaque mercury iodide.
For research on the presence of hydrocyanic acid blood or stomach contents placed in the tube, covered by a glass hanging drop 1% solution of nitrate of silver. In the presence of cyanide compounds in a drop of silver nitrate is formed cyanide silver (needle crystals form). Put some more samples.
If you suspect carbon monoxide poisoning put the sample on the carboxyhemoglobin (connection of hemoglobin with carbon monoxide). Increasingly turning to the sample Hoppe - Seyler. On the plate put a drop analyzed blood and a drop of blood without carboxyhemoglobin. To add one drop of 30% solution of caustic alkali. The blood that does not contain carboxyhemoglobin, immediately becomes greenish-brown, and blood with carboxyhemoglobin a long time does not change its color.
For samples typos prepare a water extract from the stomach or its content. The filtrate in vitro add 1 ml 5-10% solution of caustic alkalis and heated to boiling; if tifoso liquid yellow. This sample does not strictly specific.
The preliminary forensic tests carried out also during the examination of the scene for any evidence of suspicious blood or sperm. Tests on the blood varied (see the Blood, a forensic medical examination). For orientation in the presence or absence of blood or sperm applied research in ultraviolet rays. For blood stains characteristic brownish color and smooth appearance, and for spots semen - fluorescence bluish-white color (see the Seminal stains).
All the samples are preliminary and are made they should be careful not obstacles for further evidence from laboratory studies.