On Continuous Insufflation in Fowls. 



65 



of strong tonic contraction. Since the continuous insufflation 

 washes out a good part of the normal content of C0 2 and since 

 the effect and the after-effect of the insufflation practically consist 

 at all times in a tonic contraction of either the inspiratory or the 

 expiratory muscles, the conclusion seems warranted that a reduction 

 of COi in the blood does not act as a reduction of a stimulus below the 

 threshold value but, on the contrary, it serves as a stimulus for the 

 production of a tonic contraction of the respiratory muscles, while the 

 addition of CO2 assists in the maintenance of the respiratory rhythm. 



39 ("03) 



On the production of hyperglycemia and glycosuria by mag- 

 nesium salts. 



By I. S. Kleiner and S. J. Meltzer. 



[From the Department of Physiology and Pharmacology of the 

 Rockefeller Institute.] 



In their experiments on the action of magnesium salts, Meltzer 

 and Auer observed that after subcutaneous injections of magnesium 

 sulphate the urine of rabbits contains a reducing substance. 

 Underhill and Closson, who later noticed the presence of hyper- 

 glycemia after an intravenous injection of magnesium sulphate, 

 ascribed the hyperglycemia to the asphyxia which the magnesium 

 salts produced in their experiment. 



In a series of experiments which we have recently carried out 

 on dogs, all the animals had from the beginning to the end of the 

 experiment either intratracheal insufflation or the usual artificial 

 respiration. The occurrence of asphyxia was thus excluded. The 

 operative part was done under local anesthesia. In most of the 

 experiments an ikf/4 solution of magnesium sulphate was injected 

 intravenously. There was a considerable increase of the sugar 

 content of the blood after the infusion practically in all experiments. 

 In most cases the original glycsemia did not exceed 0.13 per cent., 

 while at the end of the injection or some time later, the sugar 

 content of the blood was often as high as 0.4 per cent, and even 

 higher. In blood taken about an hour and a half after the end of 



