_Grains._ Chloride of Sodium, 1.54 Chloride of Magnesia, 0.71 Sulphate of Lime, 0.128 ------ A trace of Carbonic acid, Grains, 2.378 Excess in the course of analysis .008 The second examination was made of water taken from the leaden pipes when the specific gravity was found to be 1.000.42. Upon a pint of this water being evaporated to dryness it yielded two grains of solid matter, (viz.) Carbonate of lead 164 Grains, Organic matter and salts 038 „ --- 202 „ Excess in analysis, 002 „ It therefore has been calculated that every gallon of the water used after passing through the leaden pipes, contains 1.312 grains of the carbonate of lead. Such water, although it would not speedily destroy life, would undoubtedly be attended with injurious consequences, should its use be habitually continued. On the other hand, Dr. Hare of Philadelphia, in reply to a letter requesting his opinion as to the action of the Schuylkill water[15] on lead pipes, states that after using the Schuylkill water for 25 years in his laboratory, he has never perceived the slightest indication of the presence of lead; and that if there had been any in the water, the re-agents which he has been accustomed to use must have rendered the impurity evident. If it be true that the Schuylkill water does not act upon the lead pipes, it would follow as a matter of course, if the doctrines above laid down be correct, that the Croton, which contains very nearly the same quantity of saline ingredients, would also exert no influence upon this metal. In cases, however, where injurious consequences have resulted from the agency of lead, the pipes through which the water was conducted, were of considerable length; suppose for example that the pipes are 4000 feet long, and three fourths of an inch in diameter, each portion of water will pass successively over no less than 784 square feet of lead before being discharged; and it would not therefore be at all remarkable, if the water were found contaminated with the lead. In this city, however, the pipes are rarely more than 50 feet in length, generally not more than 25, and therefore cannot exert so deleterious an influence as in those of greater extent. Dr. Chilton, recently inspected the Croton water drawn from the leaden pipes, by which it is introduced into the house of Mr. G. D. Coggeshall. No 421 Pearl-street in this city, and found the water evidently affected by the lead. He has also obtained similar results in several other instances. If the precaution be used, of not employing the water first drawn from the pipes for dietetic and culinary purposes, no injurious consequences would probably attend the use of water conveyed in this