620 Transactions of tbe American Institute, 



EXPERIMENT WITH LEAD PIPE. 



Since the last meeting the following preparation for an experi- 

 ment was made: Mr. John W. Chambers, librarian, was directed 

 to go to one of the nearest plumbing establishments and purchase 

 a coil of ordinary new lead pipe, such as is used by plimibers gene- 

 rally. He did so, in company ^nth Mr. J. Wyatt Reid, and filled 

 it with pure Croton water, taken from the same pipe which sup- 

 plies the Listitute, and, in the presence of several gentlemen, 

 sealed up both ends of the pipe. This was done on Wednesday 

 evening, just twenty-four hours previous to the meeting of the 

 Pol^ylechnic, June 6th. The coil thus sealed was carried into the 

 meeting, and there unsealed. 



Dr. D. D. Parmelee then poured a portion of the contents into 

 a glass beaker, and passed through it sulphuretted hydrogen gas, 

 when the dark color of the water revealed the presence of lead. 

 Previous to tliis the Doctor had passed the current of sulphuret- 

 ted hydrogen through pure distilled water, in the same beaker, 

 and no discoloration took place. 



Prof. Vanderweyde also examined the water from the pipe, and 

 decided that it contained lead. 



FLEXIBLE GAS-TIGHT TUBING. 



Dr. W. Rowell exhibited the improved tubing invented by W. 

 B. S. Taylor. It is made of a double tube of India rubber, one 

 within the other, and between the two is placed a preparation of 

 glue, which makes the tube entirely impervious to gas. 



Mr. Dudley Blanchard said he had noticed that the gas passing 

 through the common India rubber tubing does not make as briliiaut 

 a light as that carried through iron pipes. 



Prof. P. H. Vanderweyde said he had made bladders of glyce- 

 rine, and filled them with gas which kept for three months, and, 

 on opening them, found the gas to be pure as when fii'st put up. 



NEW PROCESS FOR MAKING ICE. 

 Prof. Vanderweyde made some experiments with the light pro- 

 ducts of petroleum, first called by him chimogene. He showed 

 how chimogene, a new liquid formed by condensing the gas 

 escaping from petroleum distillations, might be used for producing 

 ice. Placing some test tubes containing water in a glass containing 

 a little chimogene, he caused the latter to evaporate by exhausting 

 the air, and the water was immediately changed into ice. He has 



