P. J. Cammidge1 discusses in detail the "chemical pathology" of the pancreas, describing three methods, classed as A, B and C, for the examination of the urine in cases of suspected pancreatic disease. The A and B reactions were discarded because, when positive, they result in precipitates which "consist of two parts, one a phenylhydrazin compound of glycuronic acid, and the other the osazone of a sugar." To overcome this and other difficulties, the "improved" or "C" reaction was introduced, "in which the presence or absence of pancreatitis is indicated by the examination of a single specimen."
The technic of the "C" reaction is as follows:
The urine is freed from albumin (by heat and acetic acid) and from sugar (by fermentation) and filtered several times through the same paper. Forty c.c. of this clear filtrate are boiled for ten minutes with 2 c.c. strong hydrochloric
ROPER JC, STILLMAN RG. A STUDY OF THE TECHNIC OF THE CAMMIDGE REACTION AND OF THE SUBSTANCE GIVING RISE TO THE SO-CALLED TYPICAL CRYSTALS. Arch Intern Med (Chic). 1911;VII(2):252-258. doi:10.1001/archinte.1911.00060020121009