120 MADRAS FISHERIES BULLETIN VOL. XIII, 



baskets each holding below 10 lb, are introduced and remain there 

 only (I minute or two until some of the prawns begin to float ; the 

 prawns will now be brilliantly red and fully cooked. In this way 

 the prawns are subjected to the minimum boiling period and there- 

 fore lose as little as possible of their flavour and juices ; moreover 

 the shellers can at once get to work, If on the other hand a mass 

 of perhaps I cwt. of prawns is placed in a moderate sized vessel 

 such as a cast iron boiling pan, with a small amount of water, the 

 water is instantly cooled to tepidity, the prawns have to remain 

 simmering perhaps for hours, some prawns are uncooked and some 

 over-cooked, much of the value of the prawns remains in the liquor, 

 and the shellers sit idle and happy being paid by the hour. Hence 

 plenty of water at full 212'' F. and small quantities of prawns in 

 wire baskets (or ordinary baskets or nets) to facilitate introduction 

 and removal, are essential. 



185. It has been the custom to boil the prawns in water contain- 

 ing 5 to 7 per cent salt. But it is now a question under experiment 

 whether boiling should not be in fresh water; it has been found 

 that prawns boiled in fresh water can be much more easily shelled 

 than those boiled in salt water, and text books accordingly favour 

 fresh water; it is possible, however, that there maybe an unfavour- 

 able difference in weight. The matter is being fully examined 

 in two localities. It has been found difficult to keep even boiled 

 prawns over-night for packing next day ; e.g., prawns boiled at 

 Tanur where they are usually abundant, are not satisfactory if 

 kept moist, on arriving next morning at the Beypore cannery. 

 Probably a slight addition of boric acid or sodium hypochlorite 

 would enable them to keep perfectly : on arrival a washing in 

 warm water would remove most or all of the boric acid, while 

 sodium hypochlorite simply becomes sodium chloride (common 

 salt) ; any slight odour from hypochlorite quickly passes away 

 especially on cooking. Possibly, since ice is seldom available, 

 the American method mentioned below s.%\ "oysters" might be 

 useful, viz., preservation during the night in water in which I per 

 cent of bicarbonate of soda has been dissolved ; this though 

 quite innocuous, could be washed off next morning especially if 

 water slightly acidulated with vinegar is used, when sodium 

 acetate would be formed and removed. Since prawns are some- 

 times received or available in large catches it is essential to use 

 some ready and safe method of preserving them till next day ; 



