Gettlers test is done for detecting death by:

Gettlers test is done for detecting death due to drowning. According to this test, if death occured in salt water, the blood chloride concentration was greater in the left hea chambers when compared to right due to hemoconcentration. If death occured in fresh water, the blood chloride concentration was greater in the right hea chambers due to hemodilution. Diatom test can be used to differentiate between drowning and non drowning cases. According to this test if a person dies from drowning in water containing diatoms, it can be demonstrated in the lung parenchyma and in distant organs such as hea, brain, kidney and bone. Whereas if a dead body is immersed in water, diatoms can be demonstrated only in the lung parnchyma and not in other organs. Because diatoms reach the lungs by passive percolation but not to distant organs because of absent circulation. Ref: Parikh's Textbook of Medical Jurisprudence Forensic Medicine and Toxicology, 5th Edition, Page 216 and 6th Edition, Page 3.68