Fig. 1.—Kidney of Animal poisoned with White Lead (Inhalation), showing Microscopical Hæmorrhages. (Stained Hæmatoxylin and Eosin.) × 250.
Fig. 2.—Kidney of Man dying of Chronic Lead Poisoning. (Stained Hæmatoxylin and Eosin.) × 250.
Fig. 3.—Brain of Young Woman dying of Acute Lead Encephalopathy, showing Small Cerebral Hæmorrhages. (Stained Hæmatoxylin and Eosin.) × 250.
The two following cases, in which both chemical and histological examination has been carried out on the tissues of persons who had been employed in occupations which rendered them exposed to absorption of lead, and who died with symptoms directly suggestive of lead poisoning, may be added, as they confirm the experimental results given above in all particulars:
Case 1.—A woman aged twenty-one, employed in a litho-transfer works, who died after a short illness during which the chief symptoms were headache and mental clouding.
At the post-mortem examination no pathological lesions were discoverable with the exception of a small gland which had become calcareous, situated near the right bronchus. The brain was injected over the left cerebral hemisphere, but no hæmorrhages were to be seen with the naked eye. There were no other pathological signs. A portion of the brain showing the injection and congestion were submitted to histological and chemical analysis. Histologically the brain tissue was found to be normal, with the exception of slight chromatolysis of some of the larger cells; but interspersed about the whole section in the slides examined, but more particularly in the area of the cortex, minute microscopical hæmorrhages were found (see [Fig. 3]). Here and there these hæmorrhages were seen related to the expanded capillaries, all of which showed considerable engorgement with blood. The arteries and veins themselves were, in addition, considerably distended. There was no interstitial degeneration of the neuroglia noticed. A few patches were found which apparently represented old hæmorrhages undergoing gradual fibroid degeneration. In no case were the hæmorrhages of a size that could be detected by the naked eye.
Two hundred and fifty grammes of the injected area of the brain were submitted to chemical examination by the moist process described in the chapter on [Chemical Analysis]. The nitric acid filtrate from the electrolytic deposition gave a well-marked precipitate with sulphuretted hydrogen, which was filtered off and recognized as lead. There was only the merest trace of iron present. By colorimetric estimation the quantity of lead found present in the brain estimated as Pb was 0·0143 gramme. The quantity found in 250 grammes of brain substance examined from the injected area was 0·0041 gramme.
Case 2.—A man who had been employed in an electrical accumulator works for a considerable time, and who had had a history of several attacks of lead colic and one of lead paresis affecting both hands.