This section is from the book "Apicius Redivivus; Or, The Cook's Oracle", by William Kitchiner. Also available from Amazon: The Cooks Oracle.
This department of the business of the kitchen depends more upon practice than any other; a very few moments too much or too little, and the fish is spoilt. So many circumstances operate on this occasion, it is almost impossible to write rules that are generally applicable. There are decidedly different opinions, whether the water should be cold, tepid, or boiling. The Dutch, who are famous for dressing fish, always use the latter. See No. 141. We believe for some of the fame the Dutch cooks have acquired they are a little indebted to their situation enabling them to always have fish in perfection; and that the superior excellence of the fish in Holland, is because none are used, unless they are brought alive into the kitchen, (except mackerel, which die the moment they are taken out of the water.) The Dutch are as nice about this as, Seneca says, the Romans were; who, complaining of (he luxury of the times, says, they are come to that daintiness, they will not eat a fish, unless upon the same day that it is taken, that it may taste of the sea, as they express it.
On the Dutch flat coast, the fish are all taken with nets; whereas, on our rocky coast, fish are mostly caught by bait and hook, which immediately kills them. The fish are brought alive by land, to the Dutch markers in water-casks with air holes in the top. Salmon, and other fish, is thus preserved in rivers, in a well-hole, in the fishing boat.
The good folks of this metropolis are so often disappointed, by having fish which have been kept too long, they are apt to run into the other extreme, and suppose no fish will either dress well, or eat well, unless it is quite alive. Some very respectable fishmongers have, however, assured the editor, that they are oftener in danger of losing their credit, by selling fish too fresh, and that especially turbot and cod must be kept a day or so after they are dead, before they will eat well; and, like meat, require a certain time before they are in the best condition to be dressed: then they recommend them to be put into water, (salted in proportion of half a pint of salt to a gallon of water,) that you should have just stopped the boiling of, by pouring in, just before you put in the fish, a pint of cold water, and let them boil slowly till done.
 
Continue to: