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and far superior to the preparations usually employed. 

 It preserves the natural colors in almost their full 

 brilliancy, whereas spirits of any kind destroy them, and 

 both the fish and the eggs are as nearly like what they 

 appear in the water, as it is possible to conceive. For 

 microscopic observations, it is invaluable as it is perfect- 

 ly transparent and presents the growth of fungus abso- 

 lutely. Eggs that have been.kept in it for weeks, retain 

 every appearance of life, they exhibit the various stages 

 of embryonic development precisely as if they were just 

 taken from the trough, the changed colors of the living or 

 dead eggs are preserved and the outlines of the embryo, 

 its eyes, its membranes and bones are plainly visible. It 

 is said to preserve specimens uninjured for years, but 

 certainly our experience justifies us in strongly recom- 

 mending it to all who desire to preserve specimens tem- 

 porarily or for merely microscopic and scientific investi 

 gation, while we have no reason to doubt that it would 

 answer equally well tor a longer time. The objections 

 to any other preparations, are numerous, as every one 

 who has tried them is aware, but this appears to meet 

 every difficulty and can be safely used by any one. In 

 preserving the delicate and evanescent colors of fish, it 

 adds immensely to the value of the specimens, which in 

 the ordinary preserving fluid, were of a dull unattractive 

 and unnatural sameness of hue, that not only destroyed 

 their beauty but rendered them almost undistinguishable. 

 We give the letter as we receive it. 



Rochester, N. Y. 

 The preservative Fluid, which we prepared for you, for the preser- 

 vation of the ova of fishes, is composed of equal parts of Glycerine 

 and Camphor Water. The Glycerine should be the best quality — 

 (Price's English or Bower's American.) This fluid is very highly 

 recommended by Lionel S. Beale, F. R. S. Mr. Beale has prepara- 

 tions whiph have been preserved in Glycerine for twenty years. The 



