“I plead none the less for an impartial investigation of the symptoms presented by a lead-worker, before assigning full or even partial responsibility of the disease to the occupation. If any and every departure from the normal in a lead-worker is at once assigned—the occupation being known—to plumbism, early diagnosis naturally presents very few difficulties to the exponents of such methods. And however severely we may condemn in the abstract such a careless, unscientific attitude, the tendency has, in practice, to be reckoned with and combated. The balance of probabilities would possibly suggest that the occupation is, after all, responsible, in one sense or another, for the more usual illnesses classically associated with the poison; nevertheless, the attending practitioner is in duty bound to take into consideration, and to estimate the relation of, all the concurrent causes of such symptoms.”
On the extremely unsatisfactory position the certifying surgeon may find himself in at a coroner’s inquest King Alcock says:
“The problem, from a strictly scientific point of view, is complicated—one might almost say that the truth is stifled—by the fact that the ætiological relations of the symptoms of any suspended worker are swamped by the insistent legal relations under which he claims and receives compensation.
“When once a formal certificate of suspension has been issued, which has embodied a recognition of lead as a cause of certain existing symptoms, then it becomes almost hopeless ever to reopen the question of causation of these or other supervening troubles, be their origin independent of lead or not. The doctor, in a legal cross-examination, is, in scientific honesty, bound to admit at last the bare possibility of any fantastic chain of remote sequelæ; and his protests against the probabilities of such sequelæ are of no avail, as opposed to his own admission. The post, ergo propter, appeal carries the day easily.”
For the purpose of histological examination it is essential that portions of the brain, spinal cord, liver, kidney, and intestine, should be examined microscopically. The nervous tissue should be placed in formalin and Müller’s fluid, and a portion in alcohol for the examination of the fibres. The liver, kidney, etc., should be placed in 5 per cent. formaldehyde. The tissues are then treated by the ordinary histological methods, and sections prepared. With nervous tissue it is essential that those prepared for the examination of the cells should be made by the celloidin method; the others may be treated by imbedding in paraffin. The points to be sought for in the tissues are sufficiently indicated in the chapter on Pathology and Symptomatology, but may be briefly recapitulated:
In the brain, as well as in all the tissues, careful search should be made for minute microscopical hæmorrhages, and for evidences of old hæmorrhages in the form of small masses of fibrous tissue, etc. Parenchymatous degeneration, chromatolysis of nuclei, etc., nerve degeneration.
The arteries and veins should also receive close scrutiny, as the presence or absence of arteritis should be noted.
In the kidney particularly, search should be made for both interstitial and parenchymatous nephritis.
The liver frequently shows signs of microscopic hæmorrhage, and it is as well, in taking a portion of tissue for examination, to choose those portions which appear to be specially congested.
In the brain and spinal cord and nervous tissue, search is to be made for the same hæmorrhages as already noted. In addition, the condition of the nerve fibres should be noted, the presence or absence of periaxial neuritis, as well as degeneration of the axis cells, and the various ganglion cells both in the brain and spinal cord should be closely examined for chromatolysis and nuclear atrophy.