1004 TEAXSACTIOyS OT THE AMERICAN INSTITUTE. 



five years. And it is unfortunate that facts often pointing to important 

 public wants may be stated and reiterated before scientific bodies 

 without attracting the general notice which should from their natures 

 be given to them. Such was the case with the subject to which the 

 report just read relates. 



When the Board of Health became impressed, from the number of 

 accidents constantly occurring, that something was somewhere wrong, 

 they requested their chemist, Dr. Chandler, to investigate the subject, 

 and he failed to find, out of a hundred or more samples promiscuout-ly 

 purchased in the market, that any of these samples came up to the 

 requirements of a safe and good oil, with the exception of one which 

 had been received some time previous as a sample for scientific 

 examination. The Board of Health made public this condition of the 

 trade, and everybody was talking about some way to provide a remedy. 

 The mode adopted by our government for determining the safety of 

 petroleum oil does not compare in accurac3''or convenience with those 

 for testing other articles of commerce ; and, as the experiments show, 

 varies considerably with different instruments, thougli constructed on 

 the same principles. 



In answer to> the request to explain the philosophy of kerosene 

 explosions, he stated that gasoline, as it is called, is the lightest portion 

 of the petroleum, and is volatile at the common temperature of our 

 atmosphere ; so that whatever quantity there may be of this in an 

 oil it will escape if placed in a warm room or during unusual warm 

 weather, and, mixing with atmospheric air in the proportion anywhere 

 between seven and twenty per cent, constitutes an explosive mixture. 

 If less than seven per cent, ignition forms a blue flame; if more, a 

 continuous burning also takes place ; but no explosion occurs. 



This is also true with our comm(m burning gas, and many other 

 products when mixed with air in gas form. If a glass sphere be 

 filled with either of those products in gas form, and wires be so 

 adjusted as to pass an electrical spark through it no explosion or ignition 

 will take place. But if air has been mixed with it, within the pro- 

 portions stated, and the spark passed through the mixture, a violent 

 explosion follows, scattering the glass into thousands of fragments. 

 To say that any petroleum oil is absolutely as safe in every respect 

 as whale and lard oil is not really true. It may be, and is prepared 

 of so uniform quality that no portion of it will volatilize at a tempera- 

 ture likely to occur in the legitimate use of it ; but, if a lamp is broken 

 for examjjle, the oil it contains is scattei*ed over the table, floor, or 



