84 PHYSICAL CHEMISTRY IN MEDICINE. 



region was much relieved, especially during the first 

 weeks, by the sulphocyanate treatment, while other 

 methods had been without effect. Whenever the sulpho- 

 cyanate administration was interrupted, the blood-pressure 

 rose, and with it returned the old symptoms. 



Besides the decrease in the blood-pressure', a sedative 

 action may also play a role in the medicinal effects of 

 sulphocyanates. It is possible that yet another factor 

 plays a r61e, which can, however, only be touched upon 

 here. In investigations carried on during the past two 

 years with Dr. PETER RONA on the relation between the 

 effects of iodides and sulphocyanates and the effects of 

 salts of the heavy metals and the alkaline earths, the 

 following has been found: 



It has been definitely established through exact ob- 

 servation and experiment that the iodides bring about 

 and favor the excretion of the ions of the heavy metals, 

 such as lead and mercury, in cases of chronic intoxication. 

 The explanation of this fact, which has been utilized 

 therapeutically, has been sought in the formation of 

 soluble albuminates, which the iodides have been sup- 

 posed to bring about. 



When quantitative experimens on protein precipita- 

 tion are made, it is found that the heavy metals show 

 at first a rapid increase in the precipitation value, with 

 an increase in the concentration of the salt, which later, 

 however, as in the case of zinc, gradually falls to zero. 

 When the concentration of the salt is still further increased, 

 a precipitate appears a second time, which is very heavy 

 and which also is again soluble. Curves in which the 

 ordinates indicate the degree of precipitating power, the 

 abscissas the amount of salt of a heavy metal employed, 



