Palpation of the colon often shows distension, with a good deal of pain on pressure at both the hepatic and splanchnic flexures, more particularly the latter. Distinctly painful spots may be found in the length of the intestine, due to small ulcers, or more probably to the minute hæmorrhages which we have elsewhere described as associated with lead poisoning. The remaining 15 per cent. of cases have as a prodromal symptom diarrhœa. Further, diarrhœa is not uncommon amongst persons who are working in a lead factory, and who do not show other signs of poisoning; and as lead taken into the body in various ways is excreted through the fæces in common with other heavy metals, such as iron, bismuth, nickel, as well as arsenic, the occurrence of diarrhœa should suggest to the surgeon the possibility of considerable lead absorption having taken place. REFERENCES. [1] ZINN: Berl. Klin. Woch., No. 50, 1899. [2] COLLIS, E. L.: Special Report on Dangerous or Injurious Processes in the Smelting of Materials containing Lead, p. 6. 1910. [3] GRISSOLLE: Thèse, Paris, 1835. [4] MEILLÈRE, G.: Le Saturnisme, p. 122. Paris, 1903. [5] AMINO: Archiv. Ital. di Clin. Med., 1893. [6] CHATIN: Province Méd., Lyon, No. 4, 1892. [7] HARNACK: Deutsch. Med. Woch., 1897. [8] MAYER: Virchow’s Archiv, 1881. [9] HUNTER, JOHN: Observations of the Diseases of the Army in Jamaica. London, 1788. [10] MOTT, F.: Archives of Neurology and Psychiatry, vol. iv., p. 117. CHAPTER VIII EXCRETION OF LEAD =Symptomatology and Diagnosis= (_Continued_)--=Excretion of Lead.=--The two chief channels for excretion of lead are the urine and the fæces, while some include the saliva and the sweat. In the case of the sweat there is not much evidence, but a few observers, mainly French, claim to have discovered traces of lead in the skin of lead-workers. In such a case, however, it is exceedingly difficult to eliminate the question of surface contamination; and although brisk peripheral circulation and transudation may possibly carry off a certain amount of lead, the chance of this is highly improbable. There seems rather more evidence that the salivary glands may eliminate lead, as a number of other substances are undoubtedly passed in this way. Mercury certainly undergoes excretion through the salivary glands and the mucous glands of the mouth, and it is therefore not improbable that a metal so closely related in its chemical, and perhaps physiological, relations may be excreted in a similar fashion. Meillère[1] cites three instances of parotitis which were considered to be of lead origin, and further quotes an instance where, in chemical examination of the salivary glands after death, lead was found in small quantities.