TABLE OF THE VARIETIES OF NAPHTHA. +---------------------+----------------------+----------------------+ | Petroleum Naphtha. | Shale Naphtha. | Coal-tar Naphtha. | +---------------------+----------------------+----------------------+ |Contains at least 75 |Contains at least 60 |Consists almost wholly| |per cent. of heptane,|to 70 per cent. of |of benzene, C₆H₆, and | |C₇H₁₆, and other |heptylene, C₇H₁₄, and |other homologous | |hydrocarbons of the |other hydrocarbons of |hydrocarbons, with a | |marsh gas or paraffin|the olefin series; the|small percentage of | |series; the remainder|remainder paraffins. |light hydrocarbons in | |apparently olefins, |No trace of benzene or|some samples. | |C_{n}H_{2n}, with |its homologues. | | |distinct traces of | | | |benzene and its | | | |homologues. | | | | | | | |Specific gravity at |Specific gravity at |Specific gravity ·876.| |15°, ·600. |15°, ·718. | | | | | | |Distils between 65° |Distils between 65° |Distils between 80° | |and 100°. |and 100°. |and 120°. | | | | | |Dissolves coal-tar |Behaves similarly to |Readily dissolves | |pitch, but slightly; |petroleum naphtha with|pitch, forming a deep | |liquid, but little |regard to the solution|brown solution. | |coloured even after |of pitch. | | |prolonged contact. | | | | | | | |On shaking three |When treated with |The liquids form a | |measures of the |fused carbolic acid |homogeneous mixture | |sample with one |crystals, the liquids |when treated with | |measure of fused |mix perfectly. |fused carbolic acid | |crystals of absolute | |crystals. | |carbolic acid, no | | | |solution. Liquids not| | | |miscible. | | | | | | | |Combines with 10 per |Combines with upwards |Combines slowly with | |cent. of its weight |of 90 per cent. of its|30-40 per cent. of its| |of bromine in the |weight of bromine. |weight of bromine. | |cold. | | | +---------------------+----------------------+----------------------+