THE COLOUR, OF CRUSTACEANS.

Te Aroha News, Volume VI, Issue 332, 9 January 1889, Page 6

THE COLOUR, OF CRUSTACEANS.

Thc'inswpr i o ( lie question, Why doe(hi fc-hcll ot the Johsiei become red on being 1 boiled "' is, in msnoial teini^, that the salts w liieh <.\a to Make the colour in the .shell unrlei^o n < hcmk'.il change by bsing subleelcd (c tihe action of hoi. wate'. This ansuei ( an, however, hardly be a satisfactory uiio to a pci s on seeking specific infoinialion (in ihe Mibjeot ; yet it is rhe only iuimvci that can bo uhen at present. The mnttei 1^ one winch lias, app.irently excited more populai than =cientilic curiosity, for whereas the (juestion has otton been asked it ha 1 - not yet received a satisfactoi y — that i&, a specific answer. It is a question lor the chemist rather than for the natuialifcf, and tiiat, probably, is the lO'i'-on wh\ it ha's not leceived more attention. Ib is not only the lobster, but all ciustarcan^ that undergo this change of colour on being boiled. Salt-water crustaceans become redder in the process than h-csh -water crustacean?. The addition of common table salt to the water in which the eroatui c is boiled will conduce to floater icdnetss. Whether it is the sodium or the chlorine in the salt that helps to this re&ult is not known. The creature itself has nothing to do with the change in its shell, lor if the shell be taken from the living crustacean and then boiled, the result will bo exactly the same. It has been suggested that red may be the basic colour of the sholl, and the chemical change which take.-- place is merely the elimination of the other coloius. The objection is that there is no cvidciico of removal ot colour shown in the watei. The objection, ho\vever, is" not vital. r .I. ,