Fish Waste.

Southland Times, Issue 9163, 11 March 1886, Page 4

Fish Waste.

BY DB. A. P. AITKEN, . Chemist to the Highland and Agricultural , Society. At the fish-curing stations around the coaat of Scotland about 1,400,000 barrels and ber- ;.-••. - xingf and upwards of 124,000 cwt. of cod and ling were gutted and cured during the year 1884. Besides these, there were large qaan- .: tities of herring and cod gnttedand cared on board the larger fishing vessel*. The offal 1 " derived from thece cnred fish was in great measure thrown away as refuse on the shore or pitched into the sea. This has hitherto Constituted a great waste of valuable animal matter, which, with proper management, can . bfi prevented. To this waste has to be added the many cai goes of unsaleable fish referred - ; to on a former occasion. Xt is evident that - -" if means were at hand for working up this waste material in an economical way, the reinlfc would be an enhancement of the value of r ■ our fisheries Rod R cationalg&|Q. Primarily "'} ,"\ if is a matter ef importance to the fiih-curers, : "who are pu6 tb much inconvenience by the aooumulation of fish oftial in their yards, and '■ J who have ; fr« gently to suffer considerable ■' '■ loss from their inability to deal with the Rlut Of fiih which occurs when herrings are > lenii- '"'' ifuj and their sale tmremunerfttive. What in wanted, in order to give stability to their i&» ■„,,. dostry, is a method of utilising not only S«h „'"' debriti but also fish which are not edible, or ■. :.>"■■ which are tot curable, or which cannot be : cored and sold at a prcflr, The manufacture ; - of fish meal is a means to that end, Many i ''yeiira ago experiments were made by Mr Pettit in England, which resulted in his tak. 1 ; Ing dot a patent for the manufacture of ' fish ,; guano,' but the manufacture attained to no . great dimensions ia this conntryi Alwut the BRmeitifce) De Molod, in Franc?, began to m&ntifastuie o fish manure from the offal of ftbi sardine fisheries, apd more re eaily fiefa : ■ ' manures were manufactured on a l*r«e scale ■in Norway in connection with the cod fifhpry, ~ . . - which is the chief industry o? that country. ' One of the most wonderful Bights iathe ... . tt[hole i range of fisteiiea is to beteea on the northern tbcrea of x?orway, Rmong tha :,, :j ,t<o2cdtn Ulaudu, during the first three faontbs of the year. That h tbe ssavoa when ; -•'. 4he cod and ttuk, and other fisheff of the cod •"-•■-•■■ tribe, Come ia shore and ewarm among the i florde, which are their spawning gronnda. Jt • ' has been estimated that, in a square mile of %■' water there are there at thst (tea ,gjx upwards . .of R hundred railHocs of cod fish They are r , verf easily caught, and for more th^n a thou» { : : RSjnd years these waters have been frequeati d ,-. >.-, by fishfrmec from all qnarierß. A 11 et if . about- 10,000 boats will he engaged fishing *•■■■' thesa waters, and if they are moderately me- ' ' icessful tbey; will catch about 30 million V£ ;fißheß. Inhere are laigefi h-caring- establish. !- ! "ments on the shore ready to receive the cau h, ,r ,»nd the fish, wL en en red, will be exported as •."■.'.. f'fttocic'fish: for the most part to B pain, Italy, . ... -,'and.pther, Roman Oatbolic couutries.to sup; iy r- v -,; the .people, with food during Lent. Tie :-■■ method of fi h-caring is very simple. It conflists ia oboppicg off the heads of the cod, : •'■ =gtitting'tlenj, splitting them up, tak eg out , :r t^ie back: oqp, and spreading the t*?o ,iies ' •■'-'iipon the bea h, or banglcg fhera on cord*', to : ;7^y. The dry air of that northern climate " soon o-»pletts tho diying process, "Sbonld iha caleb .bg too great to be co treated, the. fish are .pot whole ico sciong brine until c ' tbe 1 pr'eeenß tf theaesayn when they ■ • *te cared &ud < sported qhitfly to Sweden and Bußsi.i. W9BT« ra^inly interested in i« what bfCptqesyf iho offal, 'j his is of various kinds, BEd'theJe sfe treated separately. The heads ..Are co'.JfC'cci and dried on the shore. The - tongtfes arc cometimes cat out and cooked, aud caomd ia the eanue way aa tinned oystets. T.hffe are exported under the n»me of 4 tuskltcn>;a f — a kind of preserve which is \v . tecororG ended aa a nutritious diet for iaralids,' •' and which has a taste and flavour somewhat resembling oyster^ though pot so delicate. " >k<' ■■■':. The most important residue is the liver. The- fat which : in sonoe fishes is dispersed throDgbont the body or accumulated under the ekin is in the cod tribe concentrated in , "sb-jot the Hyer. From this is derived J " the cod liver cil of commerce,, and thfere ac several grades of it. ,Jj£or medicinal cod-liver jioilionly.ihp pale coloured, healthy liyers are ifr-' rebosen, and tbeee.are subjected to gentle bheatiog in kettles; where..the oil leaves the livers and float 8 np, and is ran c£E as pare and ' r 'pale : as possible, when it is filtered attd sect " wtb ibe mariflt. The oil from other liven, and tbe.remaining oU from the best livers, is , '; extyactißd at a ' llgher temperature j it ii ' darker in colour, and ;s used chiefly for lubriEO«atingpnrpoßesi ■.■:•■. ? i Another-importantreidGeis thesound, of . fwimming bladder, which yields a good kind and excellent gdatina, I From, • wiifa-fsf and alio- from 'the skin and from the ;Jbpnei^4s,extrapted a very superior' kind of ..; r Bwfcpf remarkable adhesive power, . "•r*- Next to the oil, the most important ptb- . dnct is fiah meal, which is of various qtiaht<tß '•/ according .ftp the Tparl? of the fish frjoxa which it is formed, and the manner in wblch it is - ; treated. The back-bonea produce a highly i ■ phoipbatic mosl |. while the heads, owidg; to. ; ■ the amoant of flwhy aodc»r+ilagipou3 matter - and gelatine they contain, yiald a mpal rioher *|tt nitrogenous > wastH^eniff,-!':-Tbe'--ot.^ribff£l.- --• ?- «K|cV the wiidioes from the f oil and glne- inanu« ■ ■'/ : |a!Btulrea jl^d^rodfa^s^OTtf

dried by exposure to steam 4 nnder pressure, ' and subsequent pressure in a hydranlio press, which ridß them of much oil and water. After being boiled in an open kettle to free them of their remaining oil, they are again steamed inj*n apparatus which extracts a considerable , quantity of the gelatine, and thereafter they are dried by pressure and easily ground to powder. The result is that various kinds of .' fish meals are formed, which, as regards fine-, ness of condition', leave nothing to be desired. The meal formed from the more bony part of the fish has a composition and general appearance clonely resembling _steamed bong flour , tbafformed from the more gelatinous parts of the fish, and from the dried viscera and other residues contains a large amount of nitrogenous matter, and seldom Jess than 3 per cent of oil — sometimes as much as 1.0 per ctent of oil- which gives to fish manures their strong," disagreeable smell. These various grades of meal are sometimes sold separately, and sometimes they are mixed together to form a manure.of standard qnality, yielding about SO per cent phosphates and 10 percent ammom'a. 1 This is a composition which resembles in some measure that of the ammoniacal Peruvian guanos, which were commonly euoßgh imported about ten jyears ago, but .which arenow a thing of the past. It is this superficial similarity of composition, which has no, doubt -given rise to the name ''fish guano,' but that is a name which is no way expresses its character, and which should never have been applied to it ; and it would be well if the use of the word guano in con- , nection with fish manures were entirely discontinued. It misleads the farmer, and has done the manure more harm than^gojd,-