70 



PROCEEDINGS OF THE AMERICAN ACADEMY 



uniformity in results. It further suggested experiments with suspended 

 bars, the results of which are detailed in the following table. 



" Table V. — Experiments with Bars suspended out of Contact 

 with the containing Vessel. — Waters not exposed to sunlight. Av- 

 erage results of four series of experiments. One bar to each tube. 

 No concentration. 



" These experiments and the foregoing seemed to show that, without 

 contact of the solid metal with the containing vessel, the influence of 

 the 'constant condition' was so far enfeebled, after the first few days, 

 as not to have its effects recognized by the ordinary reagents, without 

 concentration, after a period of twenty-four hours' exposure. The fol- 

 lowing table of results confirms this deduction. 



" Table VI. — Experiments with Water several Weeks exposed to 

 Light and the Warmth of the Apartment in ivhich the Experiments 

 were made, by which much of the contained Air had been expelled. — 

 Bars suspended out of contact with the tube. Volume as in the pre- 

 ceding experiments. 



" As the street mains are of iron, it was desirable to know if the 

 contact of lead with iron could be more injurious to Cochituate than 

 to Croton, Fairmount, or Jamaica water. Experiments were also 

 made with Albany and Troy reservoir waters, and the Cambridge 

 well-water first in the order of succession in Table I. 



Water concentrated to one fourth of its volume. 



