Experiments on dogs, guinea-pigs, and other animals showing that acetylene has considerable toxic power. One pint of the pure gas caused severe symptoms of poisoning in dogs, and even when mixed ith air (20 per cent.) it proved fatal after an hour. If the gas was adminis tered rapidly, the animals recovered when placed in the open air, but if given slowly this did not occur, and the ani mals died. Mosso and Ottolenghi (Rif. Med., Jan. 23, '97).
A mixture of air and acetylene com mences to be explosive when it contains 5 per cent. of acetylene, whereas it re quires the presence of S per cent. of coal gas to make a similar mixture explosible. If a rabbit is placed in a bell-jar into which ordinary air and acetylene are pumped, the animal seems for a long period to experience very little incon venience. It is not until ordinary at mospheric air is excluded and only acety lene admitted that symptoms gradually and slowly develop. After a more length ened exposure to acetylene than that Ivhiell is necessary for coal-gas the ani mal becomes intoxicated, it falls over on its side apparently profoundly asleep, and, while all through the experiment its breathing has been somewhat short and rapid, stupor steals over the animal ap parently painlessly. A few inhalations of atmospheric air are sufficient to re store to the animal all its faculties. Should inhalation have been pushed fur ther and the animal have been very deeply asphyxiated, death may ensue, cyanosis, hitherto observed, being rapidly replaced by extreme pallor. In minor and easily-recoverable stages of asphyxia the vascular tension is still maintained, and there is no difficulty in obtaining a drop of blood for examination; but when the deeper stages are reached so extremely contracted are all vessels that it is al most impossible to obtain even a trace of blood. When this stage has been
reached recovery is difficult. When blood of a rabbit was examined at different stages of intoxication from acetylene, and especially in deepest asphyxia, this fluid on spectroscopic examination al ways exhibited two well-marked bands of oxyluenioglobin; also that, unlike the blood in coal-gas poisoning. although re sembling it in the cherry-red color which it presented, it was readily reduced on the application of ammonium sulphide and gentle heat. Thomas Oliver (Brit. Med. Jour., Apr. 23, '93).
It has been said that acetylene is very poisonous; the experiments of many ob servers, and especially those of ar•ant, do not confirm this statement. He proved that acetylene simply dissolves in the blood-plasma. while carbon monoxide forms a compound with the haemoglobin of the blood. Acetylene, while slightly poisonous, is less poisonous than coal-gas, and 'Vastly less than water-gas, which contains a high percentage of carbon monoxide. E. Renouf (Pharm. Era. July 20, '99).
Treatment of Acetylene Poisoning. — That fresh air should at once be given the patient need hardly be mentioned. The patient should be removed from the poisoned atmosphere into a well-venti lated room and artificial respiration prac ticed. Hypodermic injections of strych nia and digitalis should be administered, while oxygen is sent for. This gas should be inhaled as soon as practicable, while artificial respiration is continued with vigor, the patient being simultaneously rubbed. Rectal injection. of warm coffee are also useful.
In all such cases the efforts of the phy sician should be kept up a long time, the respiration and pulse being unreliable guides as regards the presence in the system of sufficient life to render re suscitation possible.
Therapeutics.—Acetylene has not been used in therapeutics.