The notification of the practitioner as a rule gives no information beyond the belief that the case is one of lead poisoning. As a matter of routine the notification is followed up by an inquiry by the certifying surgeon and inspector to see whether regulations already in force have been infringed in the particular work-place or not, and as to how far there may have been contributory negligence on the part of the sufferer. The data supplied on the surgeon’s report form the basis of the tabulation[1]. Brief explanation is wanted of the method adopted in classification. Cases represent all attacks reported within a year, and not previously reported within the preceding twelve months, so as to make the number of persons and cases in a year the same. Where the interval between two reports on the same person was more than twelve months, the fresh attack was again included. The number of such second reports on persons already included in a return numbered 284 (4·2 per cent.), and a portion of these certainly, probably not more than 100, have been included twice or thrice in the total 6,638 cases. Cases in which there was obvious error in diagnosis, or in which the opinion of the certifying surgeon was very strongly against the diagnosis (especially when the report had been made in the first instance by the occupier alone, and not by a medical practitioner), were excluded from the return. These numbered 458 (6·8 per cent.). Others, again, where there was a strong element of doubt, but not to be regarded as more than a difference of opinion between two medical men, were marked doubtful and included. Of these there were 424 (6·3 per cent.). The classification of industries was designed to represent the way in which the poisoning may be supposed to originate from (_a_) lead fumes (1 to 4), (_b_) handling metallic lead (5 and 6), (_c_) dust from lead compounds (7 to 14), and (_d_) lead paint (15 to 17). We attach now only slight importance to this attempt to define causation, as it will appear from our survey that we regard almost all cases as the result of inhalation either of fumes or dust. The reports describe not only the particular attack, but also the general condition of the patient at the time of the attack. Very frequently a combination of symptoms--colic, anæmia, and varying degree of paralysis--are described as present, and when this is the case each one of them has been entered under the appropriate heading. The total number of symptoms, therefore, greatly exceeds the number of cases, but this does not affect the correctness of the estimate of each one as a proportion on the total number reported. The reports do not give detailed information such as can be gained from hospital records. Especially is this the case with the symptoms of paralysis and encephalopathy.