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Scientific Intelligence. 



found to be analogous to any known forms, but which Mr. Lea hoped to 

 be able to make out when he should figure all the specimens and describe 

 them more at large for the Journal of the Academy. 



6. On the Composition of the Water of the Delaware River ; by Henry 

 Wurtz, New Jersey State Chemist, etc. — The water of the Delaware 

 which was submitted to analysis, was collected from the river on the 11th 

 day of September last, at a spot opposite the pump-house of the Water 

 Works, and immediately over the grating through which the water is 

 drawn to supply the reservoir. A specimen was also obtained upon the 

 same day, of the water in the reservoir, for the purpose of comparing the 

 proportion of foreign ingredients in the reservoir water, with that in the 

 river water. The spring water analysed was obtained some days later, 

 from one of the tanks from which the city was formerly supplied, in the 

 rear of the residence of Mr. Closson. 



The proportion of solid matter found in the several waters was as 



follows : 



Grains. 



In one gallon of Delaware water, 3*5346 



In one gallon of the reservoir water, 3*8555 



In one gallon of the spring water, 3*60 7 7 



For convenience of comparison, I will here quote the results of Pro- 

 fessor B. Silliman, Jr., obtained some years ago with the Croton and 

 Schuylkill waters.* 



Solid matter found by Prof. Silliman : 



Grains. 



In one gallon of Croton water, 10*93 



In one gallon of Schuylkill water, 5*50 



The most remarkable thing about these results is that notwithstanding 

 the quantity of sand, mud, and other sediment which is suspended in the 

 river water, so much as to injure the pumps, and which must be in great 

 measure deposited and separated from the water in the reservoir, the 

 latter, nevertheless, actually contains more solid matter than the river 

 water itself. This can only be accounted for by the favorable conditions 

 presented in the reservoir for the growth of minute animals and plants, 

 whose remains add of course to the weight of the solid residue obtained 

 on evaporation. My pupil, Mr. Howland Bill, has at my request - sub- 

 mitted the water in the reservoir, and the deposit formed at the bottom, 

 to a microscopic examination, and reports to me that he finds in the 

 water several varieties of animalcules and lichens or minute plants, and 

 that the sediment especially is almost wholly composed of forests of min- 

 ute plants through which roam herds of such animals as Volvox globator, 

 or " globejelly," Vibrio anser, or " goose animalcule," and several species 

 of Baccillaria and Navicula. On the surface of the water he found a 

 slight green scum, which when magnified resolved itself into collections 

 of the Cercaria mutabilis, an animal production characteristic of stagnant 

 water. Numerous large green water weeds may also be seen floating in 

 the reservoir. 



* Silliman's Journal, [2], ii, 221. 



