among the scientific institutions at home and abroad, this question appears to be solved simply and completely. It is to be hoped that the intellectual inertia, always to be overcome by new and startling ideas, however plain and well founded, may not seriously retard the spreading of the answer to the question here raised: How is a snow-crystal built?

We cannot conclude this little sketch with more appropriate words than the description of the snow-crystal given by Prof. Tyndall, in his fourth lecture of the admirable work, "Heat as a mode of motion." The great philosopher of the Royal Institution says:

"Snow, perfectly formed, is not an irregular aggregate of ice-particles; in a calm atmosphere the aqueous atoms arrange themselves so as to form the most exquisite figures. [See the figures given in the preceding parts of this article.] The snow-crystals formed in a calm atmosphere are built upon the same type: the molecules arrange themselves to form hexagonal stars. From a central nucleus shoot six spiculæ, every two of which are separated by an angle of 60°. From these central ribs smaller spiculæ shoot right and left, with unerring fidelity to the angle 60°, and from these again other smaller ones diverge at the same angle. The six-leaved blossoms assume the most wonderful variety of form; their tracery is of the finest frozen gauze, and round about their corners other rosettes of smaller dimensions often cling. Beauty is superposed upon beauty, as if nature once committed to her task took delight in showing, even within the narrowest limits, the wealth of her resources."

ON THE PRESERVATION OF ENTOMOLOGICAL

CABINETS.

BY JOHN L. LECONTE, M. D.

I HAVE tried at various times many experiments for the preservation of collections of insects, but with such limited success that I did not think the results obtained worth publishing. For the sake of deterring others from pursuing these different lines of unsuccessful attempts, it would be useful, perhaps, to give a brief account of my failures before describing a process recently devised, which seems to be both simple and effective.

Corrosive sublimate and various preparations of arsenic have been recommended by several high authorities. The former, even when most diluted, will finally render the pin brittle by the amalgam developed; the latter, when used in a very weak alcoholic solution so as to leave no efflorescence on the specimens, will preserve them well, but is troublesome to apply, as the insects must be thoroughly soaked with the fluid before being placed in the cabinet. Binarseniate of potassa being deliquescent, suggested itself to me as a material that might be applied in greater strength, and many years ago I prepared two boxes of specimens with it. They had a good appearance for some time, and have never been attacked, but eventually a considerable deposit or efflorescence came on the surface, so that the specimens required cleaning before they could be used for study..

Painting the interior of the boxes with arsenious acid was also only partially successful; I have seen, though not often, living larvæ of Trogoderma in boxes thus prepared.

Having thus failed in finding any satisfactory mineral poison I then tried the vegetable alkaloids.

I soaked specimens in moderately strong alcoholic solutions of strychnia and picrotoxia, dried them, and put them

into pill boxes with Trogoderma larvæ. After some weeks the specimens were partly eaten, and the larvæ transformed into perfect insects.

The effects of benzine and carbolic acid are powerful, but only temporary. The former is preferable on account of its less disagreeable odor, and may be used by pouring about a teaspoonful in each box; it must be renewed every four or five months.

Packing the collection in chests painted with coal-tar has been also recommended, and would certainly be efficient, but troublesome, and renders the collection, practically, nearly useless for study on account of the difficulty of access to the boxes. Surgical art has, however, given to us an instrument by which a poisonous liquid can be rapidly and most effectively applied to the entire surface of large numbers of specimens as they stand in the cabinet boxes, without the trouble of moving them. I refer to the Atomizer.

Opinions may vary as to the nature of the liquid poison to be used, but after several trials I have found the following formula to be quite satisfactory; it produces no efflorescence, even on the most highly polished species, while the odor is quite strong, and persistent enough to destroy any larvæ or eggs that may be already in the box:

Saturated alcoholic solution of arsenious acid, eight fluid ounces; Strychnine, twelve grains; Crystallized carbolic acid, one drachm; Mineral naphtha (or heavy benzine) and strong alcohol, enough to make one quart.

I have not stated the quantity of naphtha, since there are some varieties of light petroleum in commerce which dissolve in alcohol only to a slight extent. These should not be used. The heavier oils which mix indefinitely with alcohol are the proper ones, and for the two pints of mixture ten to twelve fluid ounces of the naphtha will be sufficient.

Care should be taken to test the naphtha on a piece of paper. If it leaves a greasy stain which does not disappear after a few hours, it is not suitable for this purpose.

The best form of atomizer is the long, plated, reversible tube; it should be worked with a gum elastic pipe, having two bulbs to secure uniformity in the current. The atomizing glass tubes and the bottle which usually accompany the apparatus are unnecessary: a common narrow-necked two ounce bottle will serve perfectly to hold the fluid.

I trust that the use of the means here indicated may render the preservation of insect collections less troublesome than heretofore, and thus increase the interest of amateurs who frequently become disgusted with the science of entomology, by seeing the results of years of active and intelligent labor destroyed by a few months of inattention, or by carelessness in introducing infected specimens.

A TRUE STORY OF A PET BIRD.*

BY ROBERT RIDGEWAY.

WHILE attached, during the past year, in Nevada, to the U. S. Geological Exploration of the Fortieth Parallel, under Mr. Clarence King, I had a pet bird of the species known as the Arkansas Flycatcher (Tyrannus verticalis), which is closely related to the common Kingbird or Bee Martin in form, but differs in having the back olive gray, and the under parts yellow, except the throat, which is ashy. It is to be met with over the entire western portion of the United States, from the high plains west of the Missouri River to the Pacific, and in the vicinity of settlements is well known to every one.

Our pet, familiarly known to the party as "Chippy," was obtained about the middle of July, from the Indians, who had just taken it with three others, all fully fledged, from the nest. We carried it to our camp near by, and fed it with

*Communicated by the Smithsonian Institution.

grasshoppers and flies until he was able to catch them for himself, which he learned to do about a week after he could fly. The little fellow appeared to be always hungry, and during the day followed me about, continually teasing me for grasshoppers until he had eaten enough, after which he would remain quietly upon my shoulder, or my hat, or fly off to his favorite perch-a rope running from the top of the tent to a stake in the ground. At night "Chippy" roosted upon a rope inside the tent, or frequently under an umbrella, which, for the purpose of shading a thermometer, hung at the corner outside. When wishing to go to sleep, however, he would seldom roost in these places voluntarily, but alighting upon my shoulder would hop up close to my neck and settle cosily down, and repeated removals were necessary to induce him to remain upon the perch provided for him. In the morning as I lay wrapped in my blankets, generally the first thing that awoke me would be Chippy fluttering about my head, for he would invariably select me from the dozen persons who lay around upon the ground.

Chippy soon became a general favorite, and every one fed and caressed him. First among his many peculiarities was his almost insatiable appetite, which excited the greatest wonder and comment, and many were the conjectures as to the number of good-sized grasshoppers he could dispose of in one day. It was finally agreed that this should be settled by an experiment; each person was to keep account of all he fed Chippy, and in the evening, upon comparing notes, it was found that during the day he had made away with the almost incredible number of one hundred and twenty fat grasshoppers, all however, with their legs pulled off.

Our little pet possessed scarcely a trace of timidity, and even soon learned his own name. At least, when he was wanted we had but to call "Chippy, Chippy," and he immediately appeared, even if out of our sight, joyously twittering as he approached, and alighting upon the shoulder of the person who called him. who called him. He soon began to catch insects