The Bridgeport evening farmer., 1917-04-27

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 The distinction between gasoline and the series of naphthas has large ly broken down commercially under the increasing demand, so that we may practically consider naphtha and gasoline as applying to the same fluid, using naphtha to signify both com mercial as we'll as technical naphtha and gasoline without discrimination.
 Naphtha is a hydro-carbon, that is, it is composed of hydrogen and car bon. Hydrogen is the gas which unites with oxygen to produce the hot test flame known. Carbon unites readily with oxygen with the evolu- tion of heat, practically all of the fire we know being the result of this un- ion. Coal and wood are composed chiefly of carbon.
 Naphtha is exceedingly volatile, that is, it passes off rapidly in the form of vapor when exposed to the air. This vapor Is nearly three times as heavy as air (2.77 times) and consequently
 does not diffuse or mix readily with air but is migratory" flowing like water although quite invisible; it does however, mix with air to some extent.
 As a substance naphtha contains no oxygen and will not burn until vapor- ized so that in reality it is the vapor that burns. This vapor is given of freely at all ordinary temperatures and is very combustible. igniting in- stantly upon contact with spark or
 flame or. even a sufficiently heated surface. When mixed with 2.6 per cent. of it's own volume of air the mixture becomes violently explosive,
 the explosive quality teasing when the admixtufe exceeds per cent. the power to ignite, flash and conduct fire, however, persisting very far beyond the explosive limit. The flash point, that is the temperature at which this dangerous vapor is first given off in
 consid erable quantities, is very low, the highest given by any authority be- ing Is degrees below zero, F., many stating it at a lower point. The ig- nition point. The ignition point, that is, the temperature at which this flash will ignite the substance Gin this case produce continuous vaporization and fire) is practically the same as the flesh point in all volatile naphthas. It must not be assumed that vapor- ization ceases at the low point named. On the contrary it merely slows down, so that while an open vessel of naph- tha will not ignite in response to the
 ordinary tests at that temperature, if it is kept exposed in a confined space for some time, enough vapor will ac- cumulate to flash even at lower tenn peratures than named. Heat, how ever, increases the rate of vaporization and the warmer the air and material the greater the danger.
 It is in the migrating quality that the greatest hazard of naphtha lies Most explosives require fire to be brought to them, but naphtha search es out the fire. It will run in a stream along the ground. follow down a stair way, seek out a crack in a floor at a considerable distance, and finding the fire flash it back until it reaches the point where the mixture of air and vapor is explosive (that point always exists somewhere) and ignite the va DOT upon the surface (the equivalent Of igniting the materially
 Instances are very numerous of this occurring at distances exceeding fifty feet, in many cases approximating
 300 feet and as concerns those under fifty feet, almost innumerable.
 Further, because of it's low rate of diffusion (niscibility) it will run into a pocket or depression and remain there in an explosive condition for a long time, often months Hence it is not sufficient that there be no flame in the room where it is used as