PAEATHYROID GLANDS 655 



minutes afterwards. In the other subject, though Chvostek's sign was less 

 pronounced, the spasm of the hands was more marked. A little headache 

 was noticeable early in the experiment. Tingling of the hands began in 

 about 15 minutes, becoming more intense until marked spontaneous spasms 

 of the hands occurred, Trousseau's sign becoming demonstrable several 

 minutes before the onset of the spasms. In two of the experiments this 

 subject exhibited spasm of the feet, but he did not in any of the experi- 

 ments develop spontaneous spasm of the facial muscles. In one experiment 

 he went into a complete tetanic convulsion (scream, general rigidity, 

 opisthotonos, extended extremities). Both subjects experienced tingling 

 in the muscles of the trunk on several occasions in experiments in which 

 the forced breathing was prolonged. Erb's sign, tested for in two of the 

 experiments, was positive; hyperexcitability (both cathodal and anodal) 

 developed for both opening and closure contractions. 



The following protocol of an experiment on the second subject gives a 

 good idea of the sequence of events and of some of the metabolic findings : 



SUBJECT A. G. 



Time 



Phenomena 



Before deep breathing, 



r Alveolar C0 2 tension 40 mm. 

 I Urine pH 4.9. 

 1 Blood pH 7.4. 

 [ Plasma CO 2 capacity 63.6 vol. per cent. 



After deep breathing 

 minute. . 



10th minute 



13th minute 



16th minute. . 



Starts deep breathing, rate 12 per minute. 



Slight headache. 



Tingling in hands. 



Trousseau's sign obtained. Chvostek slightly positive. 



17th minute j Both hands tingle markedly. 



20th minute Spasm of both hands. 



21st minute I Alveolar C0 2 tension 20 mm. 



22nd minute, 



23rd minute. 

 25th minute. 



Blood collected. 



pH 7.5. 



Plasma bicarbonate 45.8 vol. per cent. 

 Spasm of feet. No facial spasm. Deep respiration 



stopped. 

 Urine collected. 



pH 7.9. 



In each experiment the alveolar carbon dioxid tension was measured 

 at the beginning and at the end, use being made of the Plesch bag method 

 of collecting the air and of Marriott's colorimetric method for determin- 

 ing the CO 2 tension. The urine was analyzed for H-ion concentration 

 (method of Henderson and Palmer), for titratable acidity to phenolphtha- 

 lein as indicator, and for ammonia content (permutit method of Folin). 

 In the blood, the H-ion concentration was determined (after dialysis; 



