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PROCEEDINGS OF THE AMERICAN ACADEMY 



" Table XVI. — Determinations of Lead in Well-waters serv,ed 

 through Leaden Pipes in Cambridge. 



"TFeZZ in Boston. — 200cc., first drawn in the morning, gave, when 

 concentrated to 5cc., 0.00003gr. ::= 0.00068gr. in a gallon. Dr. 

 Charles T. Jackson has detected lead in a well-water in Waltham. 



" Well in Dedham. — lOOcc. 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. 



" Water supplied from the spring in Dedham, which is known to 

 have corroded leaden pipes, and poisoned at least one individual. — 

 lOOcc, at rest twelve hours in leaden pipe several years in use, gave 

 0.00003gr. =i0.0013gr. in a gallon. Several years since, my friend, 

 Dr. Webster, examined some of this water from the pipes of the gen- 

 tleman 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 fihn (of carl)t)nate and 

 lijdrate of lead) rose to the surface of this water, after being drawn a short time. 



