answers many purposes admirably; it is sufficiently transparent, moderately strong, and quite cheap. One having a diameter of twelve and a half inches, with a depth of eight inches, and of good thickness, can be bought for two dollars and a half; the knob on the top will prevent its standing steadily, and to obviate this difficulty a stand can easily be turned from a block of wood, with a hole cut in the centre large enough to admit the knob, and allow the bottom of the glass to rest upon it as a support. If properly taken care of, a tank of this sort will last for years, and be a great comfort to its possessor, but an untimely accident will before long induce him to try something more substantial.

Perhaps the best tank for the aquarium in use is what is called a rectangular tank, having the four sides of glass, and the base of some hard material such as stone, iron or wood. The glass is held in place, and supported at the four corners by as many pillars of iron or wood, which are held together on top by strips of a similar material connecting them. Of the three materials for the base and pillars, iron is by far the best for a fresh-water tank, if we can have but one material alone; it is lighter than stone, and the little it rusts from time to time does not amount to anything; the water does not ooze through it as it does through some kinds of stone, and it does not warp, as wood is so apt to do if the tank is left without water for a length of time. To prevent rusting a layer of cement may be spread on the bottom of the tank inside, and a plate of thick strong glass placed upon it; and in the same way a narrow strip of glass can be cemented to each of the pillars, so that the iron shall be prevented from coming in contact with the water at every point. A tank, having a base of slate and pillars of iron protected by glass, as just explained, is the best kind of a tank to own, as it can be used for either salt or fresh water as we require. The shape of a tank, too, is of some importance, that of a double cube being the best for this reason, that it allows more of a clear surface on the long sides for inspection after the rock

work and plants are introduced, than a tank whose shape is square; it also gives a better chance for the light to strike upon every point inside.

The facilities for procuring tanks already made are so great nowadays, that while once it was an object to know how to construct a tank for one's self, now one has only to make a choice from several patterns. The most important thing to look after in selecting a tank, next to its material and shape, is the kind of cement which has been used; all sorts of putty are to be rejected as worthless; if we cannot be sure that the cement is good and not injurious to fishes, a few weeks trial, or even less, will convince us of its value. Another point to be attended to, is that the cement be quite hard before the tank is filled with water, as there are some kinds of cement used that never harden; of course, in these cases there is danger of having a leaky tank to contend with.

Of the other kinds of tanks, either those made wholly of clay, or of glass, or those with one side at an angle of 50° with the base, so as to form a beach, after the pattern of the Warington tank, or those with all the sides of slate, in imitation of a rock pool, or those of an oval or hexagonal shape, each has its advocates. Some tanks have been lately made in New York, with the base and pillars of a composition which is silver-plated; they are wonderfully light and beautiful, but there seem to be doubts as to their durability. More or less ornament can be displayed on the pillars and base of the tank, according to the taste of the owner, but it seems as if simplicity and neatness were full as requisite here as elsewhere, and that the ornament of the tank should be the collection inside. As to the size of the tank, it very much depends on the place one has to put it in. These three sizes I have found from experience very useful :

No. 1, Length, 18 in.; depth, 10 in; width, 12 in. No. 2, Length, 24 in. ; depth, 14 in.; width, 14 in. No. 3, Length, 28 in.; depth, 13 in.; width, 13 in. Number three is, perhaps, the best size of all, and it is by

far the prettiest shape. Tanks can be purchased, generally, at the bird or plant stores of large cities; the prices range from six dollars upwards. Sometimes a stand for the tank is made in connection with it, or of a similar material. It is well to remember in selecting a stand, the enormous weight which it will have to bear when the tank is filled with stones and water. To be continued.

HINTS ON TAXIDERMY.

BY C. A. WALKER.

Equipment for the travelling collector.-The travelling collector should equip himself with a double-barrelled gun (and a rifle when large animals are sought for), ammunition, including shot for small birds and mammals (numbers 2, 6, 8, and 10,-the latter should never be omitted); dissecting instruments, scissors, needles and thread, preservative drugs and preparations, and alcohol about 80 per cent. in strength; tin cans of various sizes for containing alcoholic specimens, since glass bottles and jars are liable to be broken during transportation; cotton and tow for stuffing the skins of birds and mammals; fishing lines and hooks, casting net, a seine for catching fishes in small streams, the two ends of which should be secured to long wooden handles, which are held in the hands of two persons upon opposite banks; in this position it can be drawn both up and down the stream. He should also carry with him a geological hammer and steel chisels for collecting fossils and rock specimens, and small pocket vials and cork-lined boxes for insects.

Preservatives. Common powdered arsenic should be employed for skins to be mounted at once, instead of arsenical soap, as it has a tendency to dry them quickly. It may be applied dry, or mixed with alcohol until it is of the consist

ency of syrup; in the former case it should be dusted upon the skin by means of a small sieve; in the latter it is necessary to apply it with a brush. Arsenical soap should be used only upon skins which are intended to be kept for a long time before being mounted. It is composed of the following ingredients: powdered arsenic 1⁄2 lb., camphor 14 lb., salts of tartar 3 oz., powdered lime 1 oz., bar soap lb.

The soap should be cut into very fine slices, put into a tin dish with warm water, and stirred over a moderate fire until thoroughly dissolved; the powdered lime and salts of tartar should then be added and mixed with the soap. The preparation should next be removed from the fire, the powdered arsenic, and lastly the camphor (powdered and dissolved in a little alcohol) added, stirring the mixture all the while. The whole should have the consistency of flour paste; if it be too thick add a little water, taking care not to hold it over the fire after the camphor has been added, as heat will cause the latter to evaporate speedily. After cooling it place it in a jar with a brush passing through the stopper, and label the jar "poison." In extreme cases when the above preparations cannot be obtained, the skin should be rubbed with salt or with alum, or filled with spices and strong smelling herbs. These are by no means a substitute for arsenic, and are to be used only when the latter cannot be obtained. The skins of large animals should be soaked in a solution of alum, arsenic and salt, or in weak arseniated alcohol for several days.

Directions for preliminary work. When a specimen has been killed the mouth should be opened, cleaned and filled with cotton or tow; the nostrils and vent, and any wounds should be treated in the same way to prevent blood or other secretions from exuding. It is essential to remove the skin as soon as possible after death. Should this be inconvenient, the internal organs should be taken out and the cavity filled with powdered charcoal if it can be had, if not, salt should be used. Previous to removing the skin, an accurate meas

urement should be taken of the subject in the manner indicated below.*

The color and general character of the hair, as well as any change of the same at different seasons of the year, the sex, and any other peculiarity known should be carefully written

down and preserved. Skins should never be packed for transportation until thoroughly dry; they should then be placed in a box containing plenty of camphor, having its sides and joints perfectly closed with pitch to prevent the invasion of insects. It is well to saturate the inside of the box with benzine before placing the skins within. Never allow a box containing skins to be placed in any damp place.

Instruments and materials used.-Of instruments and materials useful to the taxidermist in mounting mammals, birds, fishes and reptiles, the following are needed: A scalpel

*The following are the general measurements which should be taken of a quadru ped:

Total length; nose to occiput; nose to eye; nose to ear; nose to end of tail; length and width of ears; tail from root to end of vertebræ; tail from root to end of hairs; length of the different joints of the forelegs; length of the different joints of the hind legs; forefeet from wrist; hind feet from heel; length of toes; length of nails.

Explanation of Fig. 29:-b, eye; c, occiput; d, cervical vertebræ; e, dorsal do.; f, lumbar do.; g, sacral do; h, caudal do; i, scapula; k, humerus; 7, radius; n, ulna; m, carpal bones; o, metacarpal bones; p, pelvis; r, femur; s, fibula; t, tibia; u, tarsal bones; v, metatarsal bones; w, phalanges.