PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 501 



which burns with a large flame. When it has burned sufficiently- 

 long the lid is put on, and so the flame extinguished. Suppose, 

 now, we tried to extinguish this oil with water. This would 

 simply go down in the oil, evaporate by the great heat, and the 

 steam would scatter the burning oil around and set everything 

 inflammable in the neighborhood in a blaze. I have seen in New 

 York such an effect produced on an enormous scale, when the fire- 

 men were throwing water in the centre of a large burning candle 



manufactory. 



P. H. VANDER WEYDE, M. D., 



Late Professor of Chemistry, Girard College. 



Philadelphia, September 2Uh, 1866. 



Mr. Hirsh stated in connection v^^ith Dr. Vander Weyde's letter, 

 that he had seen bone black when saturated with petroleum 

 raise the temperature to the boiling point. Benzole he did not 

 consider more dangerous than any other oil. There are only a 

 few kinds of petroleum that will heat; he had seen crude petro- 

 leum kept in tanks for two 3^ears exposed to the air, and it did 

 not decrease in the least, but became thick and tarry. 



Sulphate of Baryta. 



Mr. J. W. Chambers presented some sulphate of baryta from 

 New Haven, Conn., found some six miles from the city. 



Dr. Feuchtwanger said there had recently been considerable 

 controversy in regard to the unhealthiness of paper collars, on 

 account of the lead used in them, but now most of the collars 

 are made with barytes instead of lead. There have been two or 

 three patents issued lately, for using the carbonate of baryta; this 

 gives a gloss and does not rub off when wet, as lead does. If the 

 sulphate of baryta can be made to answer well, it will be a very 

 important matter. Barytes has also been used for giving the tine 

 gloss to visiting cards, and wall paper, and in England cotton col- 

 lars are made by its use, having all the appearance and finish of 

 linen. 



The chairman presented the following items of scientific news: 



Rhigolene. 



Dr. Biglow of the Massachusetts Medical College, recommends 



for the production of local anaesthesia the use of a petroleum nap- 



tha, boiling at 70° F. a pure hydrocarbon, which he proposes to 



call Rhigolene, from the Greek (p^yor) meaning extreme cold. 



