THE OIL CONTENT OF BLUBBER 



477 



It can be seen that the bulk of the oil is extracted in the first two hours, but even so, 

 at the end of ten hours there is still some oil left in the blubber. For this reason a 

 standard time of six hours was adopted in all experiments. Extraction was allowed to 

 proceed for six hours on a water bath, the soxhlet syphon operating about once every four 

 minutes. At the end of the first three hours the flask of the soxhlet apparatus was changed 

 for another weighed one containing a fresh quantity of carbon tetrachloride. After six 

 hours' extraction the soxhlet flask was removed immediately after the syphon had 

 operated. The carbon tetrachloride was then distilled ofl^ and the flasks were dried in 

 an air oven at 90-100° C. for three hours and then weighed. Duplicate experiments 

 on strips of blubber cut side by side were made in some cases, but in no case did 

 the two results agree to within 2 per cent, results being expressed as the percentage of 

 the weight of oil extracted in six hours to the total weight of the sample. With regard 

 to the disparity in the results obtained in the duplicate experiments it must be assumed 

 that either the error of sampling is great or else the blubber varies in composition 

 from one place to another i cm. away. It is admitted that the error of sampling may 

 be high, but as the same procedure was adopted in all cases it is unlikely that the 

 discrepancy is due solely to this cause. 



The following results were obtained : 



* Reported by Zoologists as "very lean whale", 

 f Reported by Zoologists as "very fat whale". 

 X Reported by Zoologists as "very fibrous whale". 



Sections of the blubber of all the whales in these experiments were made by 

 Mr Wheeler, and these were stained with resorcin fuchsin. Very little correlation 

 could be established between the microscopical examination of these sections and 

 the corresponding oil content figures. 



Messrs Mackintosh and Wheeler report from an examination of a large number of 

 whales at South Georgia the presence of numerous white flecks or marks on the skin 

 of the whale. These white marks are discussed on p. 373, where it is shown that they are 

 scars resulting from injuries received by the whale. 



