LEAIJ. 653

leadcn-blue line, about the onc-twentieth of an inch thick, which borders theedges of the gums attached to the necks of two or more teeth of either jaw. Inevery case of lead colic that has fallen under my care I have observed this line.Moreover, in several cases where sugar of lead, in füll doses, has been given forinany days continuously, I have noticed it; and in most of the cases it was ac-companied by abdominal pain. On two patients not known to have been sub-jected to the influence of lead I have observed some faint indication of a similarline, without, however, any constitutional Symptoms of lead poisoning. I havenot observed this line in patients under the influence of mercury. In one in-stance mentioned by Dr. Burton, fifteen grains of acetate of lead, taken in fourdays, caused the blue line: in another this effect was not produced until the pa-tient had taken one hundred and sixty grains in twenty-one days.

Salivation, (Dr. Warren, Medical Tramactions, vol. ii. p. 87.) turgidity of thegums, 1 and a bluish colour of the saliva, (Dr. Chrislison, Treatise on Poisons fp. 514. 3d. ed.) are other effects aseribed to the influence of lead. " I do notwish to assert," observes Dr. Burton, "that salivation and turgidity of the gumsare never produced by the internal Operation of lead; but I venture to aflirm theyare rare occurrences, and not characteristic of its influence."

The bluish colour of the saliva, and the blue line on the gums, probably de-pend on the presence of sulphuret of lead, formed by the action of sulphuiettedhydrogen, evolved by the lungs, on the lead contained in the salivary and buccalsecretion; for I have observed that an alloy of mercury and silver, introduced intothe hollow of a tooth, becomes coated in a few days with a black film of metallicsulphuret.

The long-continued use of the preparations of lead rarely fails to give evidenceof its effect on the muscular and nervous Systems: and which is manifested by acurious train of Symptoms, commencing with colic, and terminating in palsy orapoplexy. Lead or puinter's colic, (colica pictonum) is variable in its mode ofättack; at one time commencing suddenly, and without any very marked pre-monitory Symptoms, at another being preceded by dyspeptic Symptoms—suchas diminished appetite, with a painful and constipated State of the bowels, thefaeces being very hard. During an attack, there is usually obstinate constipation,with acute pain, rauch increased at intervals; but sometimes a relaxed conditionof the bowels has been met with. Merat {Traiie de la CoUque MelaUique.) re-fers the continued pain to the small intestines, while the more violent and inter?mitting kind resides principally in the transverse portion of the colon. Pressurerarely increases, and very commonly relieves, the pain. Cases, however, dooccur (and I have seen several) in which there is great tenderness of the bowels.The abdomen is strongly retracted, sinks in about the navel, and feels very hard.To these Symptoms may be added voiniting, cramps of the lower extremities,hard and generally slow pulse, though sometimes it has been found frequent.

De Haen and Merat, on examining the bodies of patients who have diedafTected with lead colic, found a contracted condition of the colon, and this wasconsidered bv the last-mentioned writer to indicate the seat of the disease. ButSir G. Baker, Andral, (Path. Jinat. by Townsend and West, ii. 140.) Louis,and Copland, (Dict. Prac.t. Med. i. 366.) have not, in some cases, found anyalteration. Moreover, it would appear probable from Dr. Abercrombie's obser-vations on ileus (On Diseases of the Mdom. Visr.era.) that the empty and col-lapsed portion of the intestine was not the seat of the colic, but another partfound in a State of distention,—for the collapsed or contracted State is the naturalcondition of healthy intestine when empty; while the distended portion is, inordinary cases of ileus, the primary seat of the disease, the distention arisingfrom a paralytic condition of the muscular fibres, whereby it is unable to contract

1 Dr. A. Thomson, Elements of Materia Medica, vol. ii. p. 6f

and LaiUlaw, in the Lmul. Med. liep. N, R.