At the time of the greatest activity in this field of work abroad, and with the birth of it in this country, I became interested in following cystoscopy and ureteral catheterization to the present.
In 1897 I wrote on this subject, and three years later perfected my double catheterizing cystoscope. Before and since this time much has been accomplished, and it seems almost useless to enlarge again on the diagnostic value of cystoscopy and ureteral catheterization; and such would have been my opinion had I not recently listened to one of our most learned internists from Boston, who, in his paper on "The Degree of Functional Ability of the Kidney," took up one by one of the methods at our disposal, such as cryoscopy of the blood, cryoscopy of the urine, the ingestion of anilin dyes, and disposed of all as not giving trustworthy conclusions. The three latter methods require