SEA-FISHERIES LABORATORY. 85 
THE DIETETIC VALUE OF THE HERRING. 
(With SpeecrAL REFERENCE TO THE MANX SUMMER 
pe FISHERY.) 
By Jas. Jounstone, D.Sc. 
CoNTENTS. 
PAGE 
1. Introduction “ee bt ue Se ee 4a =a es 85 
2. Methods . zi ds re: pit :¥, ue i ae 87 
3. The ealpsical ils) ag 93 
4, Composition of the flesh of Fresh Herrings, Canc | Herings pei 
Sprats fs 96 
5. The Food Value of tat Sane ie, a bP a ae 99 
6. Effects of Cooking and Curing Methods _... ie — oh) 05 
7. Composition of Cured Herrings .... a he hin Lie we 
8. The Herring as a National Food Asset oe ae Papen Gi! 
_ 9. The Analytical Data of the composition of fish flesh in we a kro 
_ 10. Some physiological questions ... ahs 5 BA on 57 PRES 
Introduction. 
This vestigation was begun in the summer of 1914 and 
had reference then to the hydrographic researches which were 
in progress. We know, in a general kind of way, that all marine 
cold-blooded animals exhibit very clearly-marked metabolic 
cycles, sexual and nutritive, and that the phases of these cycles 
are to be associated with the seasonal changes in (at least) the 
temperature, the salinity and the alkalinity of the sea-water 
which is their environment. Various indices of the metabolic 
changes have been studied. The development of the genital 
organs, the percentage of oil in the liver and other tissues, the 
growth-rates, the ‘“‘ condition” of the animal as indicated by 
its weight per unit of length, and so on. It was known that 
there were marked variations in the percentage of oil contained 
in the flesh of Norwegian Brisling and that the variation of this 
constituent ran parallel with the annual variation in sea tem- 
perature. Summer-caught Brisling made good Norwegian 
