SCIENCE. 
233 
forests, houses, other property are borne down stream. 
One gorge alone has been known to sweep away $3,000,000 
worth of property, besides making a tremendous destruction 
of life. A gorge will often require three days to pass a 
given point. 
Another enemy to investigation and to embankments are 
the snags which infest the river. These, in their worst form, 
are large trees with roots and limbs. So rapidly are they 
loosened and borne down that the government is required 
to keep several snag boats constantly at work. Perhaps the 
greatest of all enemies to embankments is the period of 
high water. At this time most of the country adjoining the 
river, known as the “ bottom lands,” is flooded to a greater 
or less depth. This is a most dangerous period, the result 
of which is awaited with anxiety by land-owners involved. 
The various floods occurring since 1850, principally in that 
year, and those of 1864 and 1874, have carried away 200 
miles of embankment between New Orleans and Cairo 
alone, which will cost the government alone $6,000,000 to 
ON THE NUTRITIVE VALUE OF FISH.* 
By Prof. W. O. Atwater. 
This paper gives the results of an investigation made 
under the auspices of the Smithsonian Institution and the 
United States fish commission. They included analyses 
of a large number of specimens of more common food 
fishes, whose details, though quite extended, were mainly 
of theoretical value. Some of the applications, however, 
were of much practical interest. In 100 pounds of the flesh 
of fresh cod we have 83 pounds of water and only 17 pounds 
of solids, while the flesh of the salmon contains only 66j4 
per cent, of water and 33 per cent, of solids ; that is to say, 
about one-sixth of the flesh of cod and one-third of that of 
salmon consists of solid, that is, nutritive substances, the 
rest being water. Lean beef, free from bone, contains 
about seventy-five per cent, water and twenty-five per cent, 
solids. The figures for some of the more common sorts of 
fish were : 
repair. 
There are many schemes offered for the construction of 
permanent embankments. Some are practicable to an 
extent, and others are but empty air. It is 
evident, however, that the government can never 
secure sufficient funds to inaugurate a system of em- 
bankments which shall have a foundation resting on the 
bed-rock below the river’s bottom. Captain Charles 
M. Scott proposes a method which is, in brief, to weight 
and sink a reach of trees with their roots in such a manner 
as shall change or keep the current within bounds. A 
careful consideration of this method shows that after every 
high-water season these trees would be “ reaching ” in all 
directions along the river. Captain James B. Eads once 
proposed a sj'stem of ditches which shall narrow the river 
in wide places and compel the current to cut a deeper 
channel. As I understand this method, it is hardly practi- 
cable. There are other methods proposed. That of Cap- 
tain Cowden is, perhaps, worthy of trial, though I am com- 
pelled to believe that it must be accompanied by a perma- 
nent system of levees. A verj' simple method, which has 
a semblance of practicability, is being experimented on 
near Omaha and at Nebraska City by Major C. R. Suter. 
An examination of this exhibits a simplicity which may 
circumvent the action of the water. No rip-rap is sunk and 
no piles are driven down. The sloping bank is covered 
with a mattress of brush. Stones are piled on this to a 
thickness of seven or eight feet, which holds the bank in 
its place and retains its sloping form. The water seems to 
have little inclination to work under this as in the case of 
a perpendicular embankment. I believe it is the invention, 
for the most part, of Professor L. E. Cooley, late professor 
of Engineering in the Northwestern University at Evanston, 
111 ., and now in charge of the works at Nebraska City, 
Major Suter also employs a simple and inexpensive method 
of changing the current of the river where it is wearing 
away the bank. A line is fastened to a buoy near the cen- 
tre. Branches of trees are tied along one-half of this, 
leaving the other half bare. Anchors are attached at both 
ends of the rope and the half without bushes is run up the 
river as a guy, while the buoy holds up the centre of the 
rope at the surface. A line of brush then runs from the 
surface diagonally to the bottom. A series of these is 
placed out in the stream near where the damage is being 
done. The sediment coming down stream catches on the 
brush, sinks and forms a bar, and either breaks the force 
of the current or throws it out into the stream away from 
the endangered bank. This latter method has long been in 
use by the.Corps of Royal Engineers with success. 
Hegar’s formula for an effective non-poisonous preserva- 
tive and antiseptic is as follows : 
R Salicylic acid 20 parts. 
Boracic acid 25 “ 
Potassium carbonate 5 “ 
Dissolve in hot water 500 “ 
Glycerine 200 “ 
Then add oil of cinnamon, oil of cloves, each 
15 parts, dissolved in alcohol 500 “ 
It is an exterminator of moths and vermin and has a 
pleasant odor. 
Solids, 
per cent. 
Flounder 17.2 
Cod - 16.9 
Striped bass 20.4 
Bluefish 21.8 
Halibut, lean " 20.6 
Solids, 
per cent. 
Halibut, fat 30.7 
Mackerel ..22.2 
Shad 30.7 
Whitefish 30.4 
Salmon 33.6 
If we take into account not the flesh only but the whole 
fish as sold in the market, including bones, skin and other 
waste, the actual percentages of nutritive material, is, of 
course, smaller. Thus the following percentages of edible 
solids were found in samples analyzed : 
Flounders 7.1 
Cod 10.5 
Mackerel 11.4 
Halibut, lean 15.6 
Halibut, fatter 27.2 
Shad .14.8 
Shad 18.7 
Lake trout .13.6 
Salmon 25.6 
The subject has of late attracted unusual attention. The 
chemico-physiological investigation of the past two decades 
has brought us where we can judge witli a considerable 
degree of accuracy from the chemical composition of a 
food-material what is its value for nourishment as compared 
with other foods. The bulk of the best late investigation 
of this subject has been made in Germany where a large 
number of chemists and physiologists are busying them- 
selves in the experimental study of the laws of animal nutri- 
tion. They have alreadjf got so far as to feel themselves 
warranted in computing the relative values of our common 
foods, and arrange them in tables, which are coming into 
popular use. The valuations are based upon the amounts 
of albuminoids, carbo-hydrates and fats, each being rated at 
a certain standard, just as a grocer makes out his bill for a 
lot of sugar, tea and coffee, by rating each at a certain price 
per pound, and adding the sums thus competed to make the 
whole bill. A table was given showing the composition of 
a list of animal foods. Thus it appeared that, while medium 
beef has about three-fourths water and one-fourth solids, 
milk is seven-eighths water and one-eighth solids. Assum- 
ing a pint of milk to weigh a pound, and speaking roughly, 
a quart of milk and a pound of beefsteak would both con- 
tain the same amount — about four ounces — of solids. But 
the quart of milk would not be worth as much for food as 
the pound of steak. The reason is that the nutrients of the 
steak are almost entirely albuminoid, while the milk con- 
tains a good deal of carbo-hydrates and fats, which have a 
lower nutritive value. According to the valuations given, 
taking medium beef at ioo, we should have for like weights 
of flesh free from bone : 
Medium beef.. 100.0 
Fre>h milk. 23.8 
Skim me i milk 18.5 
Butter 124.0 
Cheese 155.0 
Hens’ eggs 72.0 
Cod (fresh fish) 68.0 
Flounders 65.0 
Halibut 88.0 
Striped bass 79.0 
Bluefish 85.0 
Mackerel 86.0 
Halibut 88. c 
Lake trout 94.0 
Eels 95.0 
Shad — — ... 99.0 
Whitefish 103.0 
Salmon 104.0 
Salt mackerel m.o 
Dried codfish 346.0 
These figures differ widely from the market values. But 
we pay for our food according, not to their value for nourish- 
ing our bodies, but to their agreeableness. Taking the 
samples of fish at their retail prices in the Middletown, 
Conn., markets, the total edible solids in stiipedbass came 
to about $2.30 a pound, while the Connecticut river shad’s 
* Read before the A A. A. S. Boston, 1880. 
