120 



side of tlie press. From these sources it flows into a linen strainer, 

 wliicli separates the crushed seeds which have escaped from the press, 

 and then into an adjacent tank. Here, when it reaches a certain level, 

 the stopcock of a vacuum pipe in connection is opened, and the oil is 

 immediately drawn through a system of pipes into a cylinder on the first 

 floor in another part of the building, whence it passes down into the 

 first filter, which takes out all mechanical impurities. Thence it is drawn 

 into another cylinder adjacent to the first, one being empty whilst 

 the other is full, and vice versa. At this stage it may be noticed that 

 the oil is perfectly clear and bright. However, in order to get rid of 

 microscopical impurities it passes from the second cylinder into a 

 second filter, whence it is drawn into the bottling machine, where, as 

 a final precaution, it is again filtered before being run into the bottle. 

 This apparatus, which has been patented, is admirably adapted for the 

 purpose, and, as a vacuum is formed in the bottle when the outlet 

 taps are opened, cracked bottles are at once detected. The tempera- 

 ture both of the filling and bottling rooms is kept uniform day 

 and night. 



It may here be remarked that the system of filtration is through- 

 out entirely mechanical, no chemicals being employed in any part of 

 the process. In the case of the medicinal oil four separate cloths of a 

 special kind of twill are arranged in each filter. The plant has been 

 erected about four months only, and medicinal oil is expressed during 

 the first half of the week, the press being afterwards used for the 

 extraction of lubricating oil from the residue ; but from the press 

 forward the two varieties of oil pass through distinct and separate 

 systems of pipes and refining plant so as to avoid any possible contact 

 between them. Shortly, hoAvever, the two varieties of oil will be 

 made continuously, a separate press being used for each. It may 

 here be noted that the oil expressed by this process is absolutely 

 " cold drawn," the temperature of the press-room averaging 47° F. 

 This is of interest, in view of the fact that very little, if any, of the 

 so-called " cold drawn" castor oil at present in the market is properly 

 so termed. The oil, in all its stages of manufacture, has a simple 

 bland taste, resembling olive or almond oil, in marked contrast to the 

 nauseous taste usually associated with it. The press takes a charge 

 of 2 cwt. of seed at each operation, the time occupied in expressing 

 the medicinal oil being about seventeen minutes. An important 

 feature of this system of vacuum filtration is that from the time the 

 oil leaves the collecting tank until bottled it is never exposed to the 

 air, and the natural moisture of the oil is dissipated mechanically. 



