502 - PARAFFIN 



before using, and to be continually turned to free it from some of its moisture, for the 

 purpose of partially drying, when it is to be well kneaded, and again exposed to the 

 air for a few hours ; and this operation of kneading and partial drying may be repeated 

 until the compound is considered to be sufficiently stiff and plastic, as, during the 

 process of kneading or working together, it becomes extremely plastic, resembling 

 from this quality, when sufficiently kneaded, wax or clay, and it may then be worked, 

 pressed, or moulded into any required form. The compound may be kept in a plastic 

 state for some weeks, or even months before using, if required, by keeping it from 

 exposure to the air and occasionally kneading or working it together. The moulds 

 should, previous to pressing therein the compound, be brushed with oil, or with oil in 

 which is mixed a little acetate of lead. The article taken from the mould is to be 

 thoroughly dried, and afterwards it may be baked in an oven at a moderate heat, the 

 temperature to be low at first, and gradually increased, care being taken not to scorch 

 or injure the fibres of the compound. The plastic compound so made and treated 

 acquires many of the peculiarities of wood, as regards hardness and strength, and it 

 may be cut, or carved and polished, if required. Any colour may be added to the 

 compound when in a soft state, or two or more portions of the compound, stained with 

 different colours, may be worked together to form a grain to more nearly imitate the 

 appearance of wood. The use of the alkali being to render the resinous substance 

 sufficiently soluble to combine with the wet pulp, a more or less quantity than that 

 given in proportion to the resin may be used, according to the degree of solubility 

 thought to be necessary. When potash is used, it may be dissolved in water before 

 being heated with the resin. The quantity of glue may vary, and may be increased 

 to twice the quantity of resin, or even more, or sufficiently so as to dispense with the 

 acetate of lead, as it gives hardness, and with oil prevents the compound from sticking ; 

 but mixed in this manner it cannot be so well kneaded, and does not retain so fine an 

 impression. I prefer using with the ingredients as above mentioned the acetate of 

 lead ; but half a part by weight of a solution of sulphuric or other acid, diluted with 

 twenty times its volume of water, may be substituted for the one part of acetate of 

 lead. The oil mixed with the other ingredients is used to prevent the compound from 

 adhering to the surface of the moulds, but the less oil consistently with this object 

 that is used, the better. Only half the proportion of oil stated to be used as above 

 may be added at the time of mixing the ingredients of the compound, and the remainder 

 may be added during the process of kneading or working up the mass. I wish it to 

 be understood, although I prefer to use resin or rosin or pitch to form the compound, 

 that other resinous bodies soluble with alkalis may be used, as the gums copal, mastic, 

 elemi, lac, Canadian balsam, Venice turpentine, or other resinous bodies of a like kind, 

 either . separately, or mixed according to the facility with which they will combine 

 with wet pulp, and the convenience with which the compound may be worked, as will 

 be well understood by persons conversant with these substances.' 



PAPIN'S DIGESTER. See DIGESTER. 



PARAFFIN 1 ; from parum affinis, indicating the want of affinity which this sub- 

 stance exhibits to most other bodies. 



Paraffin is a white substance, void of taste and smell ; it has a specific gravity of 

 0'87 ; melts at 112 Fahr., and boils at a higher temperature, with the exhalation of 

 white fumes ; it is not decomposed by dry distillation ; burns with a clear white flame, 

 without smoke or residuum ; and does not stain paper. It is decomposed neither by 

 chlorine, strong acids, alkalis, nor potassium ; and mixes by fusion with sulphur, 

 phosphorus, wax, and resin. It dissolves readily in warm fat oils, in cold essential 

 oils, and in ether, but sparingly in boiling absolute alcohol. It has been obtained by 

 the destructive distillation of peat, wax, wood, bones, coal, and shale. 



The solid obtained is manufactured into beautiful candles, more than 5,000 

 tons being employed annually in this manufacture. The lining of beer-barrels, the 

 preserving of jams, fruits, and meats, and waterproofing and softening of fabrics, are 

 some of its patented uses. It may also be used as an insulator. Soft paraffin is much 

 employed in the lucifer-match manufacture. See NAPHTHA ; MINERAL CANDLES ; PEAT ; 

 DESTRUCTIVE DISTILLATION ; PETROLEUM. 



Paraffin is a generic term for a series of compounds of carbon and hydrogen, in 

 which the hydrogen is in the highest proportion to the carbon in which these elements 

 can xinite. Marsh-gas, the lowest member of the series, contains 1 atom carbon to 

 4 of hydrogen ; the other members thence ascend by an addition of CH* to very com- 

 plicated molecules, thus : 



CH 4 , marsh-gas or methane ; 



C 2 H 6 , ethane ; 



C'H", propane ; and so on. 



"Brodie obtained two paraffins from bees'-wax ; one had C", and the other C 80 ; while 



