CORN OILS. 9 



vanized-iron can, in the center of which was a 1-inch glass tube ex- 

 tending below a false bottom. The false bottom consisted of a 

 screen of one-fourth-inch wire covered with several thicknesses of 

 light, coarsely woven cloth. The material was packed on this false 

 bottom and the benzol allowed to percolate through it into the bot- 

 tom of the can, from which it was removed by means of the tube. 

 The benzol used in all the extractions was a pure so-called water- 

 white grade, which could be distilled completely on a steam bath 

 at a temperature not exceeding 85° C. The first extract was reserved 

 and a new batch of solvent added. The latter was allowed to pass 

 twice through the material and then set aside. A new batch of 

 solvent was added and allowed to pass four times through the ma- 

 terial. No further extraction was made, although the material still 

 contained considerable oil, especially the wet-process germs. Table 

 2 shows the quantity of oil present in the several materials before 

 and after extraction. 



Table 2.— Percentage of oil in the tvet-process and dry-process germs and in the 

 oil cake before and after extraction ivith benzol. 



Material. 



Germs: 



Wet process 



Dry process 



Oilcake: 



From wet-process germs. 



From dry-process germs. 



Percentage of oil 

 present. 



Before 

 extraction. 



50.6 

 23.4 



13.5 

 5.2 



After 

 extraction. 



7.3 

 3.1 



2.8 

 1.2 



The quantity of oil remaining in the material after the extraction 

 with benzol, especially in the wet-process germs, was considerably 

 greater than would be the case in commercial practice. 



REMOVAL OF THE SOLVENT. 



The last two benzol extracts obtained were mixed, and by heating 

 the extract on a steam bath under partial vacuum approximately 90 

 per cent of the benzol was removed. The residue of oil, together 

 with the remaining benzol, was then added to the first extract, which 

 contained the bulk of the oil removed from the material. From this 

 mixture the benzol was distilled as thoroughly as possible in the way 

 described. The last portions of the solvent were then removed by 

 passing a current of dry steam into the mixture under reduced pres- 

 sure. This treatment was continued until no more benzol collected 

 in the receiver. The oil thus obtained still had a very slight benzol 

 odor. W small quantities of water collected in the flask, this was 

 removed from the oil by settling; with subsequent filtration if nec- 

 essary. 



82270- 22- 2 



