30 PHYSIOLOGY CHAP. 



thyroid-antitoxin, and maintained that it was capable of inhibiting 

 the appearance of cachexia when injected into dogs deprived of 

 the thyroid. 



These experiments of Notkin and Frankel were abandoned as 

 soon as the work of Baumann (1895-96) appeared. He proclaimed 

 the discovery of iodine in the thyroid, and raised hopes that the 

 active principle of the thyroid had been found in an organic 

 compound of iodine, to which the name of thyro-iodine was given. 

 Baumann, with Koss and with Goldmann, Hofineister, Hildebrand 

 and Irsai, maintained that the injection of thyro-iodine into the 

 veins was able to compensate for the functions of the thyroid 

 when that organ had been excised. The experiments of Gottlieb 

 (1896), Wormser (1897), and Pugliese (1898) contradicted this 

 vicarious action of thyro-iodine. According to Wormser, thyro- 

 iodine is "neither capable of impeding the onset of an attack 

 of tetany nor of arresting an attack that is already running 

 its course." 



On the other hand, by injection of the gland, as a whole, 

 whether administered by the mouth or injected into the veins in 

 the form of an extract, in sufficient quantity, it is possible to 

 check the paroxysms of tetany, and to keep the dethyroidised 

 animals ah' ve for a long time, as was first demonstrated by Vassale. 



Other facts tell against Baumann's theory. According to his 

 own researches, the thyroid of dogs after a flesh meal contains 

 either no iodine or the merest traces of it. Iodine is rarely found 

 in the pig's thyroid ; hardly any, or merely a trace, in the thyroid 

 of sheep and horse (Topfer). The human thyroid does not contain 

 it constantly (Baumann). The subsequent researches of Neu- 

 meister and Malthes (1897) showed that iodine is frequently 

 absent in the thyroid of adults and infants, and that while that 

 of the ram and pig contains 50'9 mgrms. of iodine per gramme of 

 dry gland, that of the dog, horse, and calf contains either none or 

 merely traces of it. Thyro-iodine cannot therefore be the active 

 principle required, although it is probable that the iodine, intro- 

 duced in minute doses with vegetable aliments, is retained and 

 fixed in organic form by the thyroid gland. It has been observed 

 that the iodine of the thyroid increases after the medicinal use of 

 iodides and iodoform. 



On the other hand, the experiments of Coronedi and Marchetti 

 on the biological importance of halogens to the function of the 

 thyro - parathyroid apparatus have thrown new light on the 

 subject. They actually succeeded in rendering animals (dogs and 

 rabbits) perfectly immune against cachexia and tetany, and 

 were able to cure them easily, when already attacked, by the 

 administration of iodine or bromine in an alimentary form 

 (halogenated fats), which can easily be stored in the adipose 

 tissue of these animals, since, in comparison with normal animals, 



