February 4, 1921] 



SCIENCE 



103 



processes lie took up with Auer a careful 

 physiological study of its action. The results 

 were most interesting and important. When 

 given subcutaneously in certain doses the 

 magnesium sulphate produces a condition of 

 complete unconsciousness and muscular paral- 

 ysis or relaxation, which is reversible, in the 

 sense that when the animal is given proper 

 care it recovers. Later he was able to show 

 that out of this condition of profound de- 

 pression or inhibition the animal may be 

 restored to complete consciousness and motil- 

 ity with miraculous suddenness by the intra- 

 vascular injection of small amounts of cal- 

 cium chloride. No one who was fortimate 

 enough to see this demonstration as given by 

 Dr. Meltzer will forget its dramatic effect 

 upon his audience. A healthy vigorous rabbit 

 was brought quickly to a condition of com- 

 plete immobility and apparent death by the 

 magnesium sulphate and then even more sud- 

 denly raised from the dead and restored to 

 its normal tranquil existence by the injection 

 of some calcium chloride. Meltzer and his 

 collaborators investigated various phases of 

 this action of magnesium sulphate and all of 

 the results obtained tended to strengthen in 

 his mind the conviction that in magnesium 

 he had discovered the element in the body 

 that is especially concerned in the processes 

 of inhibition. The antagonistic action of the 

 calcium although exhibited in such a striking 

 way was not in his opinion specific. His own 

 experiments in connection with the results 

 reported by other observers led him to the 

 general view that calcium serves to balance 

 the abnormal activity of the other kations, 

 potassium, sodium and magnesimn, whether 

 this abnormal action is in the direction of 

 excitation or of inhibition. Modem work 

 upon the physiological significance of the in- 

 organic constituents of the body fiuids which 

 was begun in Ludwig's laboratory, but was 

 given its main inpetus by the striking con- 

 tributions of Ringer had concerned itself 

 chiefly with the salts of potassimn, sodium 

 and calcium, which alone seemed to be suffi- 

 cient to maintain normal conditions of 

 irritability. Meltzer's work has shown that 



magnesium also has its place in this ancient 

 balance of powers through which the func- 

 tional activity of protoplasm is controlled. 

 One can imderstand that in arriving at these 

 results he must have felt that he was approxi- 

 mating at least a demonstration of the cor- 

 rectness of his general conception of the role 

 of inhibition in functional activity. In this 

 as in all of his experimental work Meltzer 

 was eager to give his results a practical appli- 

 cation to the art of medicine. The possibili- 

 ties of the use of magnesium salts as an 

 anesthetic agent in surgical operations were 

 tested with some success on hxunan beings and 

 more important still its efficacy in controlling 

 the spasms of tetanus has had a wide and 

 promising application. 



His last extensive series of researches dealt 

 with anesthetization and artificial respiration 

 through pharyngeal and intratracheal insuffla- 

 tion. Something like twenty-eight papers, 

 most of them in collaboration with pupils or 

 assistants, were devoted to this subject. His 

 interest in this topic seems to have been stimu- 

 lated by the fact that in his use of magnesium 

 sulphate for anesthetic purposes the chief 

 danger lay in the inhibition of the activity 

 of the respiratory center. To meet this diffi- 

 culty he undertook a study of the methods of 

 artificial respiration. The initial paper in 

 1909 by Meltzer and Auer described a method 

 of artificial respiration by continuous insuffla- 

 tion of the lungs through a tracheal catheter. 

 It was foimd that by this means not only 

 could an animal be kept alive without the 

 action of the respiratory movements to fill 

 and empty the lungs, but that it furnished 

 also a convenient and efficient method for 

 anesthetization. The use of this method in 

 animal experimentation and especially its use 

 in human surgery of the thorax and facial 

 region was apparent and on many occasions 

 Meltzer sought to make known its advantages 

 and to ask for an adequate trial of its merits 

 at the hands of the practical surgeons. The 

 method has found some acceptance and the 

 application of the principle involved will no 

 doubt be extended in the future as the tech- 

 nique of thoracic surgery improves. It was 



