In acute poisoning lead is generally found in the urine, but in chronic poisoning it is by no means a common occurrence. From time to time small quantities are excreted, and in the chemical analysis made of the kidneys in cases of fatal lead poisoning a certain amount of lead has frequently been noted. Wynter Blyth[2] found in the kidneys of two white lead workers a total of 0·003 gramme. Peyrusson and Pillault[3], quoted by Meillère, found a similar quantity, 0·003 gramme, while in experimental animals Meillère himself found considerably less, only 0·0001 gramme; Stevenson, in a case reported by Newton Pitt[4], 0·0086 per cent. of lead in the cæcum and colon. Notwithstanding a small quantity of lead which may be determined by chemical methods as present in the urine or the kidney, very definite nephritis is set up in these organs, obviously due to the irritative effect of the metallic poison. =The Kidneys.=--Kidney disease of several types has been described as associated with poisoning by lead, particularly with chronic lead poisoning, where large quantities of a soluble lead salt have been ingested. Very considerable strain is thrown upon the kidney, with the result that the lead salts themselves are passed through; but, as has been pointed out when dealing with acute poisoning, the passage of lead through the kidneys does not continue for any considerable time, and in lead poisoning of an industrial and chronic nature no lead at all has been found in the urine in undoubted cases. Even when present, it may be difficult to detect unless the electrolytic method is used (see p. 174). At the same time kidney disease undoubtedly does occur in a very large number of workers. All heavy metals, of which silver, mercury, iron, zinc, and finally lead, may be quoted as examples, appear to be eliminated by the kidney when they are present in the body in toxic doses, and often when in small non-toxic doses, but in the latter case to a greater extent through the bowel than through the kidney. The lead circulating in the blood, in common with other heavy metals, may be found chemically in the kidney, but the quantity recovered is not as large as one would expect from the considerable amount of inflammation often present.