150 MADRAS FISHERIES BULLETIN VOL. XIII, 



West Coast sardine guano, are similar to those of menhaden guano 

 in the United States of America, but these latter may be very 

 slightly higher owing to the more severe pressing given in the 

 hydraulic or continuous screw presses used in the United States, 

 which reduce the residual oil to a minimum. The percentage of 

 nitrogen and phosphoric acid shows it to be a valuable fertilizer, 

 and as the stuff has been thoroughly boiled, it easily disintegrates 

 in the soil and is therefore readily assimilable by plants. More- 

 over when properly prepared and not adulterated with sand, etc., 

 it is fairly free from oil and insoluble matter, and being very dry, 

 and almost free from odour whilst dry, it is very acceptable by 

 planters since it is readily transportable and easily mixed evenly 

 with the soil ; its use is consequently growing rapidly in Southern 

 India and Ceylon; not only among planters of coffee, tea, and 

 rubber, but among ryots, as always in Japan, through the efforts 

 of the Agricultural Department. 



As a food for cattle and poultry it is useful, but in competition 

 with cheap edible oil cake of vegetable origin, it is not yet in 

 demand, though fairly well reported on by the Agricultural 

 College. 



In the United States, it is in great demand as a fertilizer, many 

 thousands of tons being annually made from the menhaden in huge 

 factories ; this fish is mentioned below, in describing American 

 practice. 



U.S.A. PRACTICE. 



6. The manufacture of oil and guano in America which will be 

 taken as the exemplar of modern practice, will now be described 

 in detail. 



7. r//i'/,s7/.-Inthe United States cf America the fish used for fish 

 oils proper, i.e., body oils derived from true fish and not from whales, 

 is almost solely the menhaden {Brevoortia tyrannus or Alosa), a 

 fish of the Clupeid family averaging about two-thirds of a pound 

 in weight, too bony to be generally edible, but containing abundant 

 oil in its tissues. The unit of catch and manufacture is 1,000 fish 

 taken as 666 lb. ; the fish are not actually counted but measured or 

 weighed by special arrangements ; the oil and fertilizer are stated 

 in terms of this unit. Being not very dissimilar, except in size, 

 from the oil sardine and both belonging to the Clupeids.. the 



