﻿50 BULLETIN" 2, IT. S. DEPAKTMENT OP AGEICULTUEE. 



recommended especially for replacing linseed oil in the manufacture 

 of patent leather and similar products and printing ink. The patent 

 leather resulting is more flexible and less liable to crack, though it 

 possesses a somewhat less glossy surface. An objection to its use 

 in this manner, however, is a peculiar efflorescence which its presence 

 causes to form on the surface of the preparation. Its moderate use 

 in the manufacture of baked japans also has been found highly 

 advantageous. 



Menhaden oil should, of course, be used with a drier, and for that purpose 

 the best results are obtained by means of a tungate drier. A tungate drier is 

 one in which tung oil, or China wood oil, is boiled with a lead and manganese 

 oxide, and when the solution is complete this is then mixed with a properly- 

 made resinate of lead and manganese. Such a drier becomes soluble in the 

 oil at temperatures over 100° C, and hardens the resulting paint very 

 thoroughly. For fabrics, however, fish oil must be heated to a temperature of 

 over 200° C, and if air is injected at such a temperature the glycerides are 

 expelled and thick oil is produced which, in conjunction with the drier just 

 named, is equally good for printing inks. It is advisable, however, to add at 

 least 25 per cent of either a heavy bodied linseed oil or a raw linseed oil which 

 does not break before the manipulation just referred to is begun. 1 



The manipulation requisite on the part of the manufacturers to 

 render their oils immediately usable for paint vehicles involves 

 merely the addition of the drier and boiled linseed oil to the fish 

 oil. The product should be sold directly to the paint manufacturers. 

 The advantages gained are a higher price gotten because of this 

 manipulation and because of the elimination of the middleman, and 

 the assurance which the paint manufacturer has that the oil pur- 

 chased directly from the manufacturer of fish oils probably is the 

 pure product. 



In this connection it should be added that undoubtedly there are 

 certain other ways, and probably many more, in which the value 

 of the menhaden oil easily might be enhanced. The considerable 

 portion of the time when, because the fish-rendering plant is lying 

 idle, the employees are unoccupied, should make it possible for the 

 operators to expend more labor on their oil with a view to the im- 

 provement of its quality, and to manipulate it to render it suitable 

 for special purposes, without greatly adding to the cost of manu- 

 facture. 



1 Toch, loc cit. 



| ADDITIONAL COPIES of this publication 

 -£i- may be procured from the Superintend- 

 ent of Documents, Government Printing 

 Office, Washington, D. C, at 10 cents per copy 



