THYROID GLAND 577 



ceased and the mind having developed, there could not be those 

 great deformities which are found in the body and mind of cretins. 

 It was observed and this is an important fact that if a portion 

 of the gland were left no evil results followed the operation for 

 goitre. 



A further link in the chain of evidence was discovered by Gull 

 in 1873. He noticed a cretinoid condition developing in adults, 

 who had previously been healthy and had not suffered from 

 goitre. The patient showed a great loss in bodily and mental 

 energy ; the features became deformed and apparently cedematous. 

 This latter change, however, was not due to a true oedema, 

 but to a collection of mucin. The disease was accordingly named 

 " myxcedema " by Ord. 



Recent observations have shown that in all cases of myxcedema, 

 cachexia strumipriva, and cretinism, the respiratory exchange is 

 diminished to one-half the normal value. The administration of 

 preparations of the thyroid gland to these patients produced a 

 marked rise in the respiratory exchange, which reached a certain 

 value at which it remained only during the continuation of the 

 treatment. 



The evidence of Medicine upon the importance of the thyroid 

 gland for the wellbeing of the organism is conclusive and cannot 

 be neglected. The testimony of Physiology is the complement, 

 for it is impossible to divorce Physiology and Medicine : diseases 

 can be considered as natural vivisections performed upon man 

 unfortunate they may be for the individual, but of benefit 

 to the race, for thereby Natural Selection and Knowledge are 

 advanced. 



It is now necessary to consider the contribution of Experi- 

 mental Physiology to the knowledge of the thyroid gland. It 

 is satisfactory to note that the results obtained agreed with and 

 amplified the clinical knowledge. Schiff, as long ago as 1856, 

 showed that complete removal of the gland was soon followed 

 by death in the case of dogs ; his results, however, were neglected 

 until Kocher and Reverdin in 1883 described the cachectic con- 

 dition produced in man by the extirpation of the gland in cases 

 of goitre. The effects of removal of the gland in cats and dogs 

 are most marked ; death generally occurs within a week. At 

 first there is a twitching of the muscles which occurs when the 

 animal is disturbed ; the contractions become more frequent, and 



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