THE CHAMBER GAS
Between 1930 and 1980, 945 men and seven women were put to death in the gas chambers of various states. 11 states have used lethal gas, these being, Arizona, California, Colorado, Maryland, Missouri, Mississippi, New Mexico, North Carolina, Nevada, New Mexico, Oregon and Wyoming.
11 men have been gassed in 5 states since the resumption of executions in 1977, these being in Arizona, Nevada, North Carolina, California and Mississippi. The last was Walter LeGrand in Arizona in 1999 (see below).
Of the 38 states with capital punishment, only Arizona, California, Maryland, Missouri and Wyoming still allow for the use of lethal gas and all offer lethal injection as an option.
Gassing is not used in by other country as a means of judicial execution.

Gassing was originally proposed by Dr. Allen McLean Hamilton who was a toxicologist and who suggested an execution method that would be more humane than hanging or shooting, which were the choices offered to condemned men in Nevada in the early part of the century. Electrocution was also seen as gruesome by the Nevada legislature and so the new method was quickly adopted, coming into law in 1921 in that state. The original idea, was to gas the prisoner in his cell, as he slept, without prior warning. This proved impracticable and thus the gas chamber, as such, was invented by Major Delos A Turner, an army medical corps officer and was first used in 1924.

The first person to die in Nevada's new gas chamber was Chinese born Gee Jong on the 8th February 1924 for the murder Tom Quong Kee, a member of a rival gang. His lawyers had fought a long battle in the courts to show that the gas chamber was a "cruel and unusual punishment" and as such was illegal under the Eight Amendment to the Constitution. The execution commenced at 9.30 a.m. when Gee Jong was led from a holding cell and secured to the chair within the chamber. He appeared to struggle a little after the gas was manually pumped in and then lapse into unconsciousness but as no external stethoscope had been used he was left in the chamber for 30 minutes to ensure death.

It is difficult nowadays to imagine a more cruel, expensive, or dangerous (to the staff and witnesses) method of execution than gassing. The prisoner is expected to contribute to his (or her) own death by actively inhaling the lethal fumes in a mechanism that cost a fortune to buy and is likely to leak deadly fumes if it is not meticulously maintained. Execution by lethal gas requires considerable preparation and always takes several minutes to cause death after the cyanide pellets drop into the acid. The prisoner generally struggles and shows signs of great suffering.
California has executed 192 men and 4 women by gassing at San Quentin prison, between 1938 and 1994. The first gas executions at San Quentin took place at 10.00 a.m. on December 2nd 1938 when Robert Lee Cannon and Albert Kassell were put to death simultaneously for the murder of a prison warden. The cost to the state of this, for the cyanide and acid, was $1.80. Ethel Leta Juanita Spinelli became the first woman to be executed in California and the first woman to die in the gas chamber, when she was executed for murder on November 21, 1941.

The California gas chamber at San. Quentin (pictured) is in a basement room and is a pale green painted octagonal metal box, six feet across and eight feet high, built in 1938. There is a 30 feet high chimney outside to take the gas away.
The entrance is through a steel door closed by a large locking wheel onto rubber seals. There are windows in five of the sides for the witnesses to view the execution.
Inside the chamber are two identical metal chairs with perforated seats, marked "A" and "B." (The two chairs were last used in a double execution in 1962) Two guards strap the prisoner into chair A, attaching straps across his upper and lower legs, arms, thighs and chest. They will also affix a long Bowles stethoscope to the person's chest so that a doctor on the outside can monitor the heartbeat and pronounce death. Beneath the chair is a bowl filled with sulfuric acid mixed with distilled water, with a pound of sodium cyanide pellets suspended in a gauze bag just above. After the door is sealed and when the warden gives the signal, the executioner, in a separate room, operates a lever that releases the cyanide into the acid. This causes a chemical reaction that releases hydrogen cyanide gas, which rises through the holes in the chair. (2 NaCn + H2SO4 = 2 HCN + Na2SO4)

Prisoners are advised to take deep breaths after the gas is released as this will considerably shorten their suffering. Easy for the Warden to say, no doubt, but much harder for the prisoner to intentionally inhale the gas designed to kill them, even if they accept the logic of the advice they are given.
A typical witnesses' view of gassing is as follows "At first there is evidence of extreme horror, pain and strangling. The eyes pop, the skin turns purple and the prisoner begins to drool".
In medical terms, victims of cyanide gas die from hypoxia, which means the cut-off of oxygen to the brain. The initial result of this is spasms, as in an epileptic seizure. Because of the straps, however, involuntary body movements are restrained. Seconds after the prisoner first inhales, he/she will feel himself unable to breathe, but will not lose consciousness immediately. "The person is unquestionably experiencing pain and extreme anxiety," according to Dr. Richard Traystman of John Hopkins University. "The pain begins immediately and is felt in the arms, shoulders, back, and chest. The sensation is similar to the pain felt by a person during a heart attack, where essentially the heart is being deprived of oxygen." "We would not use asphyxiation, by cyanide gas or by any other substance, in our laboratory to kill animals that have been used in experiments."

A study of the execution records of 113 prisoners executed at San Quentin showed that the average time taken to kill them was 9.3 minutes. The prisoner will usually loose consciousness between one and three minutes after the gas hits their face and the doctor will pronounce them dead in around ten to twelve minutes. An exhaust fan then sucks the poison air out of the chamber. The corpse is sprayed with ammonia, which neutralizes traces of the cyanide that may remain. After about half an hour, prison staff enter the chamber, wearing gas masks and rubber gloves. Their training manual advises them to ruffle the victim's hair to release and trapped cyanide gas before removing him.