430 KELSOK W. JANNEY 



equal or in favorable instances, excel the normal growth curve. In adults 

 the aim of treatment is to reduce the weight to normal and maintain it 

 there. One of the first indications of insufficient dosage in hypothyroid- 

 ism of adults is a gain of weight. If, as sometimes happens, the affected 

 individual has always been obese, the ideal weight for the sex, height and 

 age may be accepted as a criterion of treatment. 



Regular and accurately taken records of the height of children are of 

 much importance in determining whether true growth has been resumed. 

 Such estimations are best made at monthly intervals. 



The leucocytic formula is of some aid to treatment but only of confirm- 

 atory nature. The per cent of polymorphonuclear elements tends to rise 

 as the mononucleosis and lymphocytosis subsides. (Falta (.), Esser.) 

 The writer has frequently observed the same reaction. The differential 

 count is so readily taken and recorded that it is surprising that this clinical 

 feature has been so often neglected. The secondary anemia rapidly dis- 

 appears in well treated cases, the hemoglobin and red cell count rising to 



the normal. 



Thyroid Preparations and Dosage. Since Murray's first success, a 

 variety of thyroid preparations have been used as therapeutic agents. 

 These preparations usually took the form of impure extracts or derivatives 

 of the thyroid, therefore of dubious efficiency. It seems unnecessary to 

 perpetuate remembrance of the same by special mention. With the recent 

 isolation of the thyroid hormone by E. C. Kendall (/), there began a new 

 era in thyroid physiology and therapy. A detailed description of the prep- 

 aration and the chemical properties of thyroxin is not pertinent to the pres- 

 ent clinical article and will be found elsewhere in the present work. The 

 thyroid hormone or thyroxin has been demonstrated by Kendall and 

 Plummer to possess practically all the therapeutic effects ascribable to 

 the thyroid gland or any of its preparations. These observations have 

 been corroborated by Janney, Rowntree and co-workers. We are then in 

 final possession of the active principle of the thyroid gland which can be 

 prepared chemically pure, be accurately weighed, measured and prescribed. 

 Thyroxin is now obtainable commercially in doses of 0.2, 0.4, 0.6, 0.8 

 and 1.0 mgni. The smaller doses are efficacious in mild hypothyroidism, 

 the larger being usually necessary in cretinism or myxedema. It is usually 

 administered by mouth though good results of intravenous injections 

 have been reported. (Kendall, Rowntree.) Overdosage will produce a 

 toxic state of so-called hypothyroidism and even death. (Kendall.) It is 

 remarkable that a latent period of a number of days' duration passes 

 l>efore the effects become evident, also that the therapeutic effect once 

 established tends to persist for a certain time. In view of this fact, it has 

 become the writer's custom to administer but a single daily dose which has 

 practical advantages. If toxic doses are administered, the latent period 

 is much shortened (24-30 hours for animals). The elevating action on 



