Practice is the only safe guide, as circumstances, geological, physical, and meteorological so vary the conditions of works that no definite rule of procedure will avail. Earnest work and close observation, combined with ready resource, are the only safe guides to success. Troubles of some sort are sure to supervene; the man who succeeds is he who can anticipate, and so remedy them. To be always on the watch and notice the first indication is a very safe maxim, more easy to inculcate than to put in practice.
There can be no question but that the practical removal of difficulties in the path of fish culture is work of the highest value, well worthy the attention and acknowledgment of those in authority at Whitehall and elsewhere at home, as has been the case abroad.
SIR,--Your correspondent "C. C. C." in _Land and Water_ of last week disagrees with the constant and free use of earth, which I had advocated in my article on fish culture which appeared the preceding week. Naturally one must admit that earth at the bottom of a pond is not so great an element of beauty as is clean gravel, but the advantages are so many, that beauty must give way to usefulness. Besides this, "C. C. C." must know that it is almost impossible to keep the gravel clean enough to look pretty, when the water is inhabited by a large number of little fish which are being constantly fed. I cannot at all agree with his advice that "earth should be avoided, or only used when necessity dictates." I believe that one of the first principles of success in fish culture is always to prevent any disease or mishap, rather than to wait for, and then try to remedy it. Trout in their natural surroundings get a dose of earth every time that there is a spate. It is very evident that the earth contains some ingredients which are not only beneficial but almost a necessity to the fish.
I have never heard of earth as an actual cure for "fungus" and should hardly think that it is active enough. There is, however, no doubt that it is one of the best preventatives to "fungus," for if it is properly and freely used it stops all chance of any decomposing material being exposed to the action of the water, and laying the fish open to the chance of a great many evils.