Page:The Zoologist, 4th series, vol 4 (1900).djvu/423

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Formaldehyde as an aid in collecting ornithological specimens is the subject of a communication by Mr. Joseph Mailliard to the last number of the 'Auk' for July. It appears that formalin can be procured at a much lower rate under the trade name of "formaldehyde." By its aid the collector is placed in an independent position in regard to the number of specimens he may collect in a day, as with its aid he can keep a number in good condition until time admits of preparing them for his collection. With an old-fashioned veterinary hypodermic syringe, and a bottle of saturated solution of formaldehyde, Mr. Mailliard is now provided on all his expeditions. This syringe holds one teaspoonful, and this is sufficient for a bird as large as a Partridge. The sharp needle is punched into the abdomen in one or more places, a few drops are sent down the throat of a bird to be saved, and, if to be kept for some days, a little is injected into the brain by opening the bill and forcing the needle upwards and backwards between the eyeballs. In place of a regular hypodermic, a common glass syringe, or even an eye-dropper, can be made to answer, especially if the end is heated and drawn out to a sharp point, as in an egg-blower. The amount injected and the strength of the solution must depend upon the size of the bird. Formaldehyde comes in saturated solution of nominally 40 per cent., while from 4 per cent, to 10 per cent, is what may ordinarily be used. For birds up to the size of a Partridge, 4 per cent, is sufficiently strong; from this to the size of a Duck, 8 or 10 per cent.; and for Geese and very large birds a comparatively smaller amount of the full strength seems more satisfactory than a larger amount of a weaker solution. It is well to avoid, as far as possible, having one's hands come in contact with the strong solution, as this is apt to harden the skin of the fingers, and cause cracks, into which arsenic may be introduced. Upon the basis of the original solution being 40 per cent., it is a simple matter to approximate any desired strength by mixing in a separate bottle one part of the solution to so many parts of water roughly estimated. The strength and amount necessary for different birds will soon be learned with a little practice. If too much or too great a strength is used upon small birds, the body becomes more or less hardened and dry, making it exceedingly difficult to skin the specimen. Care must also be taken to avoid using more than is absolutely necessary in the throat, as the thinness of the gullet allows the formaldehyde to act directly upon