Fetid Odours of Fish Oils. 259 



chloride of lime. This agent does not seem to possess the pro- 

 perty of depriving, to any extent, fish-oils of their proper or 

 natural odom* ; as, for example, it has little efPect upon fine 

 sperm oil, but its operation seems to be chiefly confined to the 

 removal of the fetor which is the result of putrefaction. Hence 

 the more fetid the oil, the gi-eater Avill be the change effected 

 by the process. The quantity of chloride of lime required va- 

 ries according to the putridity of the oil ; but, in general, 1 lb. 

 of it is sufficient for 112 lb. of oil, but, if the oil be excessively 

 putrid, li or 2 lb. may be required. The process is the follow- 

 ing : — Take 1 lb. of chloride of lime, and about twelve times the 

 quantity of water. Triturate the chloride of lime in a mortar, or 

 in an apparatus of a similar kind, gradually adding a portion of 

 the water, so as at first to form a smooth and soft paste, and 

 then the remainder, v/hich will give the whole the consistence 

 of cream. The object of this careful trituration is to break 

 down every particle of the powder, so that it may be capable 

 of intimate combination with the oil. Mix this thoroughly 

 with the oil by frequent and careful stirring. Let them remain 

 united for a few hours ; then add 1 lb. of sulphuric acid, pre- 

 viously diluted with 20 or 30 parts of water, and boil, with a 

 gentle heat, constantly stirring during the process, until the 

 oil drops clear from the end of the piece of wood Avhich may be 

 employed for this purpose. After the boiling has been finished, 

 allow the oil to settle for a few hours ; then draw it oif from 

 the acidulated water. A common cast-iron boiler, lined with 

 lead, is best adapted for this process, as being less acted on by 

 the chloride of lime and acid ; but a copper or iron vessel will 

 answer the purpose, if the quantity of acid be not too great. 

 For the trituration of the chloride of lime, however, mortars 

 of iron or copper should be avoided. Fish-oil treated in this 

 manner seems to burn equally well as the same oil which has 

 not undergone this process ; and a very ready and convenient 

 method of trying it is with a floating light. 



Glasgow, 19M April 1838. 



