CONCERNING KEROSENE. 257 



time a method of refining petroleum bad been generally introduced, by 

 which a large proportion of the total burning-oil produced consisted of 

 mixed or cracked oils. Such a proportion of high-test oils as were 

 demanded by the market was made, but the great bulk of the distil- 

 late had been converted into a cracked or mixed oil. The petroleum 

 was distilled but once, the naphtha was removed, and then the remain- 

 der of the oil manipulated to produce such crude burning-oils as were 

 desired, leaving in the still only a small percentage of residuum. 

 These crude burning-oils were treated with sulphuric acid and caustic 

 soda in such a manner as to produce the lightest colored oil possible, 

 and they were further manipulated to bring the test within the legal 

 requirements. As it was much less difficult to bring the mixed or 

 cracked oils within the requirements of a burning rather than a flash 

 test, the burning test has always found strong advocates among a cer- 

 tain class of the manufacturers of petroleum. This method of manu- 

 facture was well established, and the markets of the world were well 

 accustomed to handling the various pi'oducts during that period when 

 the bulk of the crude oil came from the Butler-Clarion district. But 

 gradually, as has been stated, the major portion of the crude oil that 

 flowed into the pipe-lines was no longer from the Butler-Clarion wells, 

 but from those of Bradford. By the end of 1881 more than three 

 quarters of the crude oil was Bradford oil, and the relative proportion 

 has steadily increased. This change in the crude material has been 

 accompanied by a corresponding change in the character of the prod- 

 uct. Instead of mixed and cracked oils, consisting largely of normal 

 burning-oil, the products of Bradford crude oil consist largely of the 

 products of destructive distillation, and this is due to the fact that the 

 petroleums of the Butler-Clai*ion and Bradford districts represent two 

 extremes ; the first contains the smallest proportion and the latter the 

 largest proportion of paraffine-oils of any crude petroleums found in 

 large quantities. The proportion of cracked oils in the distillate from 

 the Butler-Clarion petroleum was too small to injure the general qual- 

 ity of the oil. In the Bradford distillates, on the contrary, the prod- 

 ucts of destructive distillation give character to the whole. And not 

 only is this statement true, but the proportion of high-test normal oils 

 to be obtained at present from the pipe-line crude oil has gradually 

 become so reduced that the best brands of oil on the market have 

 deteriorated, until it is very difficult, if not impossible, to purchase 

 an article of burning-oil equal in quality to the best offered for sale 

 a few years since. All this time the requirements of law in regard 

 to test have been met, perhaps it may be said, with increased faith- 

 fulness. 



From the foregoing pages it must be manifest that any improve- 

 ment in the increasingly bad quality of kerosene can be looked for 

 only from one of two directions. Either it must come from the devel- 

 opment of a new field for crude oil of superior quality, or from the in- 



TOL. XXTII. 17 



