W. GODDEN 423 



Laboratory Tests. 



For the purpose of the laboratory experiments a strip from the 

 middle of each cake was used. This was ground as finely as possible, 

 a sample drawn for immediate analysis, and then lots of 200 grams of 

 each cake taken and incubated under the following conditions: 



Exp. 1. The ground cake was placed in a wide-mouthed bottle, 

 8 % of water was mixed in with it, the bottle loosely corked, and the 

 whole incubated at 37° for twenty-six days. 



Exj[>. 2. Similar to Exp. 1. The cakes were weighed before and 

 after incubation. 



Exp. 3. In addition to the 8 % of water, 5 c.c. of toluene were added 

 to each cake in order to prevent mould formation. 



It will be noted that, in each case, the cakes were kept in a confined 

 space, in moist condition and at a relatively high temperature, con- 

 ditions which may be regarded as likely to ensure a severe test of keeping 

 properties. 



During the periods of incubation in experiments (1) and (2) the 

 first cake to show mould was the "soycot," which was distinctly mouldy 

 at the end of two days. This was closely followed by cottonseed, 

 ground-nut and soya cakes in the order named. At the end of four 

 days the palm kernel and coconut cakes, though showing no signs of 

 mould formation, had an ethereal and at the same time a somewhat 

 cheesy smell. At the end of the period of incubation the four first- 

 named cakes were mouldy throughout the whole mass, the "soycot" 

 and soya cakes having a smell resembling that of fish meal. The linseed 

 cake showed a development of mould at one spot but, apart from a 

 slightly mouldy smell, no other change was apparent. Neither the 

 palm kernel nor coconut cakes showed any sign of mould formation, 

 but the cheesy smell was intensified in the case of the former. During 

 the incubation in the presence of toluene (Exp. 3) there was no develop- 

 ment of mould on any of the cakes, nor was there any noticeable change 

 in appearance or smell. 



As in the case of the cakes stored at the farm, the oil extracted 

 after incubation shows a much higher free fatty acid content than before, 

 the rise in most cases being of the same order as that found in the farm 

 tests. The one exception is the soya cake where the rise is much greater 

 as a result of incubation in the moist state than from storing at the 

 farm, this difference being due probably to the fat-splitting action of 

 the moulds formed on the cake during incubation. In contrast with 



