PETROLEUMS 433 



cocaine, chlorodyne, morphine, or atropine. In the symp- 

 tomatic treatment of tetanus and nervous diseases it is 

 given to allay excitement. For destroying the strongyles of 

 hoose in calves, and soothing consequent irritation, Williams 

 prescribed H\x. to H\xx. of acid, conjoined with sodium 

 carbonate and gentian. Hobday suggested the use of 

 hydrocyanic acid as an antidote in cases of respiratory 

 failure under chloroform. A full dose frequently starts 

 respiration with a few deep gasps. 



DOSES, etc. Of the B.P. two per cent, acid, horses and 

 cattle take Tl\xx. to H\lx. ; sheep, Ti[x. to Tl\xv. ; pigs, JT\ij. 

 to TT^vij. ; dogs, TT|rj. to H\iv. ; given in water sweetened 

 with syrup. As the soothing effects are transient, suitable 

 doses may be repeated three or four times daily, but their 

 effects should be carefully watched ; while, to prevent 

 mistakes which are apt to occur with such a poisonous, 

 colourless liquid, it is often made up with compound 

 tincture of cardamoms. For external use it is diluted with 

 two hundred parts of water, a few drops of glycerin being 

 added to retard evaporation. Lotions must be cautiously 

 applied, especially where the skin is broken. But the 

 potassium or other soluble cyanide being stable and not 

 volatile, is more convenient for most external uses. 



PETROLEUMS OR PARAFFINS 



Hard paraffin. Paraffinum durum. A mixture of several 

 of the harder members of the paraffin series of hydrocarbons ; 

 obtained by distillation from shale (B.P.). 



Liquid paraffin. Paraffinum liquidum. A clear, oily 

 liquid, obtained from petroleum, after the more volatile 

 portions have been removed by distillation (B.P.). 



Soft paraffin. Paraffinum molle. A semi-solid mixture 

 containing soft members of the paraffin series of hydro- 

 carbons ; obtained by purifying the volatile portions of 

 petroleum (B.P.). 



The petroleums or paraffins are hydrocarbons, produced 

 by the decomposition of vegetable matter. They are ob- 

 tained from the destructive distillation of coal, from bitumin- 

 ous shales, and from the oil-wells found in various parts of 



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