THE PARATHYROID GLANDS 553 



parathyroids in the process of separation, and this might account for the 

 traces of iodin found in the parathyroids of this animal in their analysis. 

 The same may be said in the case of the human parathyroids. Their con- 

 clusion is that, if present at all, iodin occurs in such minute quantities in 

 the parathyroids as to be of no functional significance, and that there are 

 no chemical grounds for the hypothesis that the thyroid and parathyroids 

 belong to the same physiological system. 



The work of Berkeley and Beebe along these lines has already been 

 adverted to. In attempts to obtain the active principle of the gland they 

 used a normal saline extract of ox parathyroid. This contained a mixture 

 of nucleoprotein, globulin, and albumin, which they proceeded to separate 

 chemically. They divided the protein content of the extract into three 

 portions, "the first being precipitated by acetic acid, the second by half 

 saturating the filtrate with ammonium sulphate, and the third by com- 

 plete saturation with ammonium sulphate." Following the common 

 nomenclature, they speak of these proteins as nucleoprotein, globulin, and 

 albumin. The nucleoprotein was by far the most abundant, the yield 

 being five times as great as that of the globulin, while the albumin was 

 present in very small quantity. After purifying the nucleoprotein and 

 globulin, their actions were tested on animals suffering from parathyroid 

 tetany, and from the results the authors believed that the active principle 

 was contained in the nucleoprotein alone. "The nucleoprotein of the 

 parathyroid, when freshly prepared, is equal to the whole gland in reliev- 

 ing the symptoms of acute tetany in dogs," while the globulin had no such 

 effect. Boiling the nucleoprotein, or keeping it at a temperature of 80 C 

 for half an hour was found to destroy its activity completely; it rapidly 

 deteriorated in solution or in suspension at refrigerator temperature, 

 while freezing also destroyed its activity. Tryptic or peptic digestion for 

 forty-eight hours severely impairs, but does not completely destroy its 

 activity. These properties would seem to show that the active principle 

 belongs to the class of enzymes, rather than to that of the autocoids. They 

 state that it relieves tetany when administered by mouth, but it acts more 

 rapidly and effectively when given by subcutaneous or intraperitoneal in- 

 jection. 



The action of the globulin was always negative, and the albumin was 

 not obtained in sufficient quantity to permit of the biological test being 

 applied to it. 



Berkeley and Beebe found no evidence of iodin in any of the parathy- 

 roids which they examined human, dog, or ox. 



In 1905 Vassale (c) prepared an extract from the parathyroids by a 

 "special method," which he does not describe, and found it to be effective 

 when given orally, or by subcutaneous injection in eclampsia, infantile tet- 

 any, and epilepsy. 



The resemblance of some of the symptoms of parathyroid tetany to 



