REPORT ON THE SALUBRITY OF THE MYSTIC WATER. To find the effect of Moseley's tannery on the composition of the water of the Charlestown Water Works, it is necessary to know: — 1st. The composition of the water immediately above the tannery; and 2d. That of the water below the works before the addition of water from any new source; 3d. The volume of water passing through the tannery and discharging into the Abajonna ; 4th. The composition after passing through the tannery, and before discharging into the river; 5th. The effect upon this water of discharging it into the larger volume of the Abajonna; 6th. The volume of water passing through the aqueduct, and over the dam and river at the gate-house. For the better understanding of the whole subject it is desirable, in addition, to take into account the composition of the water of the Abajonna at a point above any manufacturing establishments that may be charged with adding foreign matter to the stream; also, that of the water at the mouth of the Horn pond stream or Wedge pond outlet; the larger source of the supply to the upper Mystic pond before it united with the Abajonna below Moseley's; and, lastly, of the water as it enters the aqueduct at the Gate-house. I accordingly collected water: 1st. From the Burbank pond, above the lace-leather fac tory, or Frye's tannery, about two miles from Moseley's tannery, toward the sources of the Abajonna. 2d. From under the bridge of the highway, crossing the Abajonna immediately above Moseley's tannery. 3d. From the archway of the Boston and Lowell railroad, below the tannery. 4th. From the head of the drain leading from the tannery into the Abajonna. 5th. From the mud at the bottom of the drain. 6th. From the still water over the delta at the mouth of the drain. 7th. From the mouth of the Horn pond stream, in the archway of the Woburn Branch Railroad. 8th. From the Gate-house. Numbers five and six were collected on the 15th of November last (1872); all the others on the 26th. The water from the pond on the Abajonna, above the lace-leather factory, the normal water of the drainage of contains of grains in one gallon, the Mystic basin, Salts. 2.27 Organic matter. Total. 3.22 Between this pond and Moseley's tannery there are several manufacturing establishments, including an extensive glue stock factory. There are several ponds and marshes on the stream, all the waters of which pass under the highway bridge immediately above Moseley's tannery, and at a short distance from the mouth of the pump pipe, through which water is drawn for the main supply of the reservoirs of the tannery. At that point below the bridge, I collected water for analysis. It contained in one gallon, Salts. 3.21 Organic matter. 1.04 Total. 4.25 Mr. Moseley's tannery is situated on a little rise of land, on the right bank of the stream; and directly below the establishment a pond spreads out, through scattered swamp shrubbery, chiefly on the right side of the river, like the loop of a capital P, while the main current of the stream preserves its course to the left of the pond. This pond gives great stillness to the water into which is delivered the drainage from the tannery. Between the tannery and the water is a margin of swamp muck, which has been covered with spent tan bark. Within this strip of land, above high-water mark, is a long line of parallel and connected trenches, which has been dug to allow the wash water from the scouring and beaming of the leather and hides to settle. At the end of it, where it discharges into the drain, is a charcoal filter, through which the water, after slowly flowing through a channel a thousand feet long, must finally pass. Beyond the charcoal filter it unites with water from the other parts of the tannery and passes through the open drain to the pond below the works. The soil under the tan bark is saturated with the extract of the tan bark, and to some extent, this extract finds its way to the drain and the pond below. Near the lower end of the pond lying in the bayou below the factory, the water passes through an arch under the Boston and Lowell Railroad. It carries with it the total effect of the Moseley tannery. I collected the water of the Abajonna where it enters the archway under the Lowell Railroad. It contains in one gallon, Salts. 3.22 Organic Matter. Total. 4.92 A gallon of water collected at the Gate-house contains, Salts. 3.942 Organic Matter. Total. 5.30 3.22 Pond above Lace Leather Factory. It now appears that more than three-fifths (3) of the foreign matter in solution at the Gate-house is due to the incidental and inevitable drainage of the soil of the Mystic basin above all the factories. Of the remaining (less than two-fifths), the share contributed by Moseley's tannery will appear from the following: The open drain leading from the tannery is about one hundred and fifty feet long, and presents a dead level of pulpy, yellowish and dark-reddish mud, offensive to the sight, and such as to induce a superficial observer to infer that the works must more or less injure the water. The light granular matter so objectionable to the eye is found, however, not to be especially offensive to the taste or smell. It proves, on examination, to be mainly composed of fine particles of leather, removed in the scouring process. The smell is that of new leather, with no smell of decomposition; and the taste that of leather and salt. The extent of the possible injury to the water from the matters discharged into the drain has been subjected to determination. Mr. Sawyer found, as the result of prolonged hydraulic observations, that the water discharged through the common drain of the tannery amounts to 13,000 gallons in twenty-four hours 4.25 From these results a profile may be drawn which will illus trate the changes in the composition of the water. Above Mose- |