"The effect of temperature was sought in a variety of ways. The following experiments are recorded.

“TABLE XIV. — Experiments with Bars previously coated, exposed to direct Sunlight from the 21st to the 26th of June. - Bars resting on the bottom of the tubes.

"The influence of extreme temperature and exposure to air and moisture, under the most favorable circumstances, was ascertained by transmitting steam mixed with air through a leaden pipe thirty-six feet long, coiled like a still-worm, and placed in cold water to produce condensation. One hundred and ten cubic centimetres of the condensed water, after acidulation with acetic acid, were treated with a stream of hydrosulphuric acid. The precipitate was collected on a filter, previously dried at 100° C., and gave 0.0225gr. of sulphide of lead, equal to 0.0196gr. of lead; which is equivalent to 0.8095gr. of lead in a gallon. Whatever influence might result from such changes, it must be remembered that pipes under ground will preserve a tolerably even temperature; and be the effect of increased heat what it may, it has been more energetic in Philadelphia than it ever can be in Boston.

"The effect of increasing the percentage of common salt is exhibited in the following table.

“TABLE XV. — Experiments with Cochituate Water and graduated Solutions of Common Salt. — Bars and volumes as in the foregoing experiments. No concentration. Bars resting on the bottom of the

* Dr. Hayes has observed that elevation of temperature increases the quantity of lead dissolved in a given time. - Report of the Consulting Physicians, 1848, p. 24.

"1st. The immediate effect of the salt in preventing the action on lead by lessening the solvent power for air; and

"2d. The influence of salt in dissolving the coat formed, by double decomposition, or by the formation of the double salt of the oxide and chloride; as shown in the last suite of results.

"The preceding experiments, as a whole, go to show that Cochituate water may be distributed through iron mains and leaden service-pipes with as little danger as Schuylkill, Croton, or Jamaica water.

"The consideration that was to give value to these determinations was that of the health of the citizens of Philadelphia, New York, and Boston, so far as it might be influenced by the waters served through lead in the respective cities. This was to be decided, as already intimated, by an appeal to the most enlightened testimony that could be furnished; that of eminent physicians of extensive practice in the localities where lead pipe is employed."

Professor Horsford then adduced a summary of the numerous medical opinions, chiefly compiled from letters addressed to himself, and which have been already published in the Appendix to the Water-Commissioners' Report of August 14th, 1848.

"The decision of this question does not depend upon the presence or absence of a minute quantity of lead in water that has been standing a given length of time in leaden pipes, or upon the absolute freedom from corrosion of pipes long in use. For if a certain quantity, more or less, has found its way into the human system in the every-day regular use of Croton and Schuylkill waters, then must the human system be capable of sustaining without injury this quantity; and the possibility of receiving an equal quantity hereafter by those who drink Cochituate water may be contemplated without solicitude, since the experiment has been made.* Nevertheless, examinations for lead have been made in many well-waters, and also in Croton, Jamaica, Schuylkill, and Troy waters, and Dedham spring water. The results follow.

*To this point more particular reference will hereafter be made.

"Well in Boston. concentrated to 5cc., 0.00003gr. 0.00068gr. in = Charles T. Jackson has detected lead in a well-water in Waltham. "Well in Dedham. 100cc. of water standing over night in the pipe serving from the reservoir supplied by a forcing-pump, concentrated to 5cc., gave a trace of lead.

200cc., first drawn in the morning, gave, when a gallon. Dr.

=

"Water supplied from the spring in Dedham, which is known to have corroded leaden pipes, and poisoned at least one individual. · 100cc., at rest twelve hours in leaden pipe several years in use, gave 0.00003gr. 0.0013gr. in a gallon. Several years since, my friend, Dr. Webster, examined some of this water from the pipes of the gentleman who was made ill, and detected lead, without concentration, by treatment with sulphide of ammonium.* This branch pipe was 150 feet in length. The main pipe, two inches in diameter, is about three quarters of a mile long. This pipe must be capable of holding a gallon in a little more than seven and one third feet, or 540 gallons in its whole length. Thus, the entire morning draught of spring water of each

* Such was the quantity of lead in solution, that a white film (of carbonate and hydrate of lead) rose to the surface of this water, after being drawn a short time.

family had ordinarily been at rest twelve hours in the main and lateral pipes. In some instances it had doubtless been longer at rest; and yet, so far as I have been informed, but one well-established case of lead disease is known to have occurred from the use of this water.

“TABLE XVII. — Determinations of Lead in the Croton Water of New York. Drawn, after thirty-six hours' exposure, from leaden pipes, at seven different localities, in the neighbourhood of John Street.

Bottles.

500cc. reduced to 10cc. gave, of Sulphide of Lead, 00

1.

2.

"1000cc. derived from bottles 1, 2, and 3, concentrated to 10cc., gave, with hydrosulphuric acid, a precipitate which, ignited with saltpetre and redissolved, gave, with bichromate of potassa and hydrosulphuric acid, distinct precipitates of lead. The whole quantity equalled about 0.0001gr., or for a gallon 0.00045gr.

"Determination of Lead in the Schuylkill Water of Philadelphia. - According to Professor Booth, 100 apothecaries' ounces, after exposure 36 hours in leaden pipe, a year and a half in use, concentrated to the bulk of half an ounce, gave not the slightest discoloration after transmitting hydrosulphuric acid through it for an hour.

"Troy Reservoir Water. 2000cc., 24 hours at rest in leaden pipes several years in use, gave, when concentrated to one hundredth of its volume, no trace of lead.

"TABLE XVIII. Determinations of Lead in Jamaica Water served through leaden Pipes in the City of Boston.

Exposed to
the Lead.

Gave of Sulphide of Lead.

200cc., 12 hours, reduced to 20cc. 00

66

No. 800 Washington Street, "

No. 10 Tyler Street,

"April 13th. Worcester Railroad Depot, 1000cc., exposed to the lead 36 hours, reduced to 20cc. gave, of sulphide of lead, 00gr.

"June 19th. Worcester Railroad Depot, 500cc., exposed to the lead 36 hours, reduced to 5cc., gave, of sulphide of lead, 0.00002gr. 0.00018gr. in a gallon.

"The magnitude of this quantity, and the influence its known presence in a water should have, may be over-estimated.

500 cubic centimetres contain 0.00002gr.

"Wiesbaden water contains of arsenious acid, in 1000cc., 0.00045gr.,t -a quantity more than ten times as great as the lead in Jamaica water, and yet this water is renowned for its medicinal virtues. It may be said, that the arsenic is in combination with oxide of iron. Chevallier and Gobley have come to the conclusion, that its occurrence in springs is not dependent upon the presence of iron. It is found in water whose character is determined by the presence of carbonic acid or sulphates. This body occurs in solution in waters from nine mineral springs in France. Its occurrence in Germany has been recognized, among others, by Will. Tripier found it in Algiers.

"The appearance of leaden pipes taken up after several years' use, in New York, is what might have been expected. I have examined twelve pieces from as many different localities. Most of the specimens that had been in use for only one and two years were covered with a bluish-gray coat, and some of them could scarcely be distinguished from ordinary pipe for sale in the shops. A specimen in use five years is coated with a transparent, exceedingly thin, reddish-brown film, apparently composed of organic matter, oxide of lead, and oxide of iron. The crystalline laminæ upon the inner surface, characteristic of new pipe, are to be seen with the utmost distinctness, and present, with the exception of the coating, no appearance distinguishing it from new pipe.

"Jamaica pipe, in use from fifteen to twenty years, is coated with a thick, reddish coat, which, when dry, may be readily disengaged, and in one specimen examined shows traces of slight corrosion beneath. The corrosion from without was such as to have nearly eaten through in some places. The lead of this pipe contained great proportions of antimony where corrosion occurred, but no sulphide of lead, which, I am informed, occurs in much lead pipe.

*

Precipitate ignited, redissolved, and re-precipitated.

+ Compt. Rend., Tom. XXIII., pp. 612-615, 634, 635.

‡ Journ. de Ph. et de Ch., 3 Ser., Tom. XIII., pp. 324 – 333.

§ Ann. der Chem. und Pharm., LXI., pp. 192–204.