Robert Chesebrough

“ The residuum left in the still by the vacuum process is greater in amount and better in quality than that produced by the old method, owing to its having been subjected to much less heat and to not having been run down so low in the still. The residuum produced by the vacuum process makes, therefore, a better quality of vaseline than that produced by the old process, and is more easily and cheaply refined by filtration through bone-black, but the products from both are identical in properties and appearance. ”

“ It will not saponfiy, does not crystallize, and does not contain paraffine, and in this respect essentially differs from the heavy products of petroleum which have been subjected to destructive distillation, and which are known as paraffine-oils. ”