The experimental work therefore carries us very considerably forward in correlating the symptomatology and pathology of lead poisoning. The symptoms produced in susceptible animals by the actual inoculation of a lead compound differ only in degree and rapidity of onset from those produced in animals submitted to inhalation with similar compounds. Feeding, on the other hand--that is, ingestion by way of the gastro-intestinal canal--even in large quantities, did not produce poisoning to any great extent, except when some material such as alcohol was added, thereby breaking down the animal’s resistance. Another interesting fact is given--that if lead is taken by the mouth in addition to milk a great deal of the poisonous effect is got rid of; thus of two animals--Nos. 46 and 47--which received lead nitrate in their food, the one in water and the other in milk, the one which received it in milk showed no effects even after four months’ experiment, whereas at the end of four months the animal which was receiving the compound in its water died. This brings out a point already insisted upon--namely, that in all lead factories it is highly important that no work should be undertaken first thing in the morning, before the workers have had a proper meal, and that in the absence of a proper meal milk is the best substitute. It is highly probable that the soluble lead salt becomes united in some form of albuminate which is dealt with later, and perhaps turned into a sulphide and excreted without absorption. There is no possible doubt, from the large series of experiments which I have performed, that lead inhaled is far more poisonous than when absorbed in any other way; further, that the amount of poisoning produced differs somewhat according to the type of compound inhaled, and the experiments, moreover, give some suggestion as to the dose which is likely to produce poisoning. It is seen, where the animal is inoculated with white lead, the dose required to produce symptoms is below 1 gramme per kilogramme of body weight, but above 0·2 gramme per kilogramme of body weight. In feeding, 0·8 gramme, and even 1 gramme, per diem for eighteen months produces no effect, although the same quantity plus an excess of alcohol rapidly produces the disease. On the other hand, as small a dose as 0·1 gramme of nitrate of lead given in water for four months produced death.