Paraffins

Paraffins (Lat., parum, little; affinis, like). The name paraffin was first given to a waxy substance which was obtained from the tar resulting from wood distillation. This substance, however, as well as certain liquids obtained naturally or by artificial means, was found to consist chemically of a mixture of hydrocarbons all intimately related to one another, and to which the name was then given as a generic term. Hence the paraffins are hydrocarbons which may be represented by the general formula Cnll-n + ?. They vary considerably in characteristics, from the gas methane (q.v.) CH4, to higher solid members in which the number of carbon atoms maybe as many as sixty. They all are incapable of uniting directly with other, substances to form addition-compounds, and are hence termed saturated compounds. They give rise by substitution of hydrogen to a very large number of compounds of different types, as acids, alcohols, etc. The paraffin wax and oil both consist of mixtures of these compounds. That used for illuminating purposes is a thin liquid obtained by the distillation of natural petroleum (q.v.), or from carbonaceous shales. During this process a number of oils are obtained, which have to be separated to some extent by fractional distillation. The more volatile portions, which are not suitable for illuminating purposes, are very largely employed as solvents for organic products - e.g. caoutchouc, resins, etc. The next portion of the distillate is used extensively for lamps and as fuels. The higher boiling portions cannot be well used in lamps, but find application as lubricants, and to an extent also as fuel, while the last parts which are solid at ordinary temperatures are employed in the manufacture of candles, usually mixed with stearin, as otherwise the candle is of too soft a consistency.