SCIENTIFIC REPORTS. 



I.— ON THE DECOMPOSITION OF FISH. By Dr. A. G. Anderson, 

 M.A., M.D., B.Sc, D.P.H., Assistant to the Medical Officer of 

 Health, Aberdeen. (PL I.) 



Table op Contents. 



Page. 



1. Introduction : General Review and Discussion, . . 13 



2. Criteria to be Considered, ..... 17 



3. General Appearance : Handling a Fish, ... 17 



4. The Firmness, Softness, &e., of the Fish when Handled, 18 



5. Appearance of Surface and Scales, . . . 18 



6. Appearance of the Eyes, ..... 18 



7. Appearance of Gills, ..... 18 



8. Smell, ....... 19 



9. Reddish Discoloration of Ventral Aspect of Backbone, . 20 



10. Rigor Mortis, . . . . . . 21 



11. Detection of Rigor Mortis^ .... 25 



12. Trawled Fish compared with Line Fish, ... 25 



13. Manner in which Flesh strips away from Backbone or 



Bone away from Flesh, ..... 26 



14. The Appearance of Abdominal Walls as aflfected by the 



Gut, ........ 26 



15. Distribution of Bacillus Coli in Fish, with Tables of 



Experimental Data, ..... 30 



16. Bacteriological Examination of Fresh Peritoneal Fluid, 



in Fish, chiefly for Bacillus Coli, ... 35 



17. The Bearing of the Distribution of Bacillus Coli in Fish 



and other Lower Animals on Public Health Questions, 35 



18. Summary regarding Detection of Decomposition in Fish, 37 



19. Explanation of Plate, ..... 39 



1. Introduction: General Rbvibw and Discussion. 



During the past two years, in my capacity as Assistant to the Medical 

 Officer of Health in Aberdeen, I have had frequently to deal with 

 hygienic problems relating to trawling, fishcuring, and the examination 

 of fish. In many cases I have been unfavourably impressed with the 

 lack of knowledge of the elementary scientific principles underlying the 

 various processes in the different departments of the fishing industry, 

 and with the absence of a spirit of scientific enquiry which is so essential 

 in any progressive business. It was with the aim of stimulating this 

 spirit of enquiry that I commenced some practical studies — the results of 

 some of which arc included in this paper — and in the hope that fishermen, 

 fishcurers, and meat inspectors might gain a more intelligent acquaint- 

 ance with their business, and that thereby the fish-consuming public 

 might also be benefited. I was, moreover, asked by the Fishery Board 

 for Scotland to undertake an investigation on the processes involved in 



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