
IN RELATION TO DIET. 603 
tants of the sea on which fish feed ;—to mention only what I have ascertained 
myself,—in the common Shrimp I have detected it in an unmistakeable manner, 
and also in the Lobster and Crab; and likewise in the common Cockle, Mussel, 
and Oyster. 
The medicinal effects of cod-liver oil, in mitigating if not in curing pulmonary 
consumption, appear to be well established. And as this oil contains iodine, the 
analogy seems to strengthen the inference that sea-fish generally may be alike 
beneficial. ; 
Should further inquiry confirm this conclusion, the practical application of it 
is obvious; and fortunately, should fish ever come into greater request as articles 
of food, the facility with which they may be preserved, even without salt, by 
thorough drying, would be much in favour of their use. I lay stress on thorough 
drying, as that seems essential,—for preservation, I believe even hygroscopic water 
should be excluded. Even in the instance of those articles of food which can be 
preserved in their ordinary dry state, the expulsion of this water would be advan- 
tageous under certain circumstances, were it merely on account of diminution of 
weight. Thus, referring to the second table, it will be seen that the Pemican, 
carefully prepared in the Portsmouth Victualling Office, lost by thorough drying 
13°75 per cent., so much being the water it contained in a hygroscopic state,—a 
lightening of weight that, to the Arctic land explorer, could not fail to be welcome 
and useful. 
The inference regarding the salutary effects of fish depending on the pre- 
sence of iodine, in the prevention of tubercular disease, might be extended to 
some other diseases, especially to that formidable malady goitre, the mitigation 
or cure of which has, in so many instances, been effected by iodine ; and which, 
so far as I am aware, is entirely unknown amongst the inhabitants of seaports 
and sea-coasts, who, from their situation, cannot fail to make more or less use 
of fish. 
Amongst the many questions that many be asked in addition to those I have 
proposed, I shall notice one more only, and that in conclusion. It is, whether the 
different parts of the same fish are likely to be equally beneficial in the manner 
inferred,—the beneficial effect, it is presumed, depending on the presence of iodine. 
From the few experiments I have yet made, I am led to infer, reasoning as be- 
fore, that the effects of different parts will not be the same, inasmuch as their in- 
_ organic elements are not the same. I may instance liver, muscle, and roe or milt. In 
the ash of the liver and muscle of sea-fish, I have always found a large proportion 
of saline matter, common salt abounding, with a minute portion of iodine,—rather 
more in the liver than in the muscle,—and free alkali, or alkali in a state to occa- 
sion an alkaline reaction, as denoted by test paper; whilst in their roe and milt 
I have detected very little saline matter, no trace of iodine, or of free alkali; on 
VOL. XX. PART IV. 8A 
