Discussion at annual convention

W. A. Del Mar: I would like to ask the author why the successive tests were made on the same sample of oil. We have done a good deal of oil testing, and have always taken the precaution to pick out fresh clear samples for the tests. I am wondering whether more uniform results would be obtained if a fresh sample of oil were used for each test, than if you used the same sample five hundred times? It would seem that the matter of the chemical decomposition of the oil would enter into the problem, and that has not been mentioned in the paper.