The difficulty of estimating lead present in these gastric digestions is a very real one, as, owing to the precipitation of lead by various fluids of an albuminoid nature, it is difficult to determine the amount of lead present in a given quantity of digest; moreover, in making such a digest, much of the material may become entangled among the clot of the milk in a purely mechanical fashion, and, in attempting to separate the fluid from the other portion of the digest, filtration no doubt removes any lead which has been rendered soluble first of all, and reprecipitated as an albuminate. An albuminate of lead may be formed with great ease in the following way: A 5 per cent. solution of albumin in normal saline is taken, 0·02 per cent. of hydrochloric acid is added, and 10 per cent. solution of lead chloride added as long as a precipitate is formed. The precipitate is then filtered off, and washed in a dialyser with acidulated water until no further trace of lead is found in the washings. A portion of this substance taken up in distilled water forms a solution of an opalescent nature, which readily passes through the filter and gives the reaction of protein with Millon’s reagent, and the lead reaction by means of caustic potash and sulphuretted hydrogen, but very large quantities of mineral acid are required to produce any colour with hydrogen sulphide. Lead which gains access to the stomach, either dissolved in water or swallowed as fine dust, becomes in all probability converted first into a soluble substance, chloride, acetate, or lactate, which compound is then precipitated either by the mucin present in the stomach, or by the protein constituents of the food, or by the partially digested food (peptonate of lead may be formed in the same way as the albuminate described above). In this form, or as an albuminate or other organic compound, it passes the pylorus, and becomes reprecipitated and redigested through the action of the pancreatic juice. A consideration of the action of artificial gastric juices and the properly combined experiments of gastric and pancreatic digestions suggest that the form in which lead becomes absorbed is not a chloride, but an organic compound first formed and gradually decomposed during the normal process of digestion, and absorbed in this manner from the intestine along with the ordinary constituents of food. Dixon Mann[13] has shown that about two-thirds of the lead administered by the mouth is discharged in the fæces, and that the remaining one-third is also slowly but only partially eliminated. This point is of very considerable importance in relation to industrial poisoning of presumably gastro-intestinal origin, and consideration of the experiments quoted suggests that the digestion of albuminate or peptonate may to some extent be the basis which determines the excretion of so much of the lead via the fæces. This alteration of solubility has no doubt a bearing on the immunity exhibited by many