nineteen-twentieths of all our avian fauna, and as each is figured in bright colours (a trifle too bright, perhaps), our readers may form some idea of the pictorial wealth of this book. The eggs of each species are also figured and naturally coloured, and we must bestow a word of praise on the really artistic manner with which the delicate tints, and shades, and markings are all given. As each is of the natural size, this part of the book cannot but be of great value to the student. The plan of figuring both birds and eggs is a good one. The letter-press is clear, and the paper good, whilst the authors have collected a good deal of sound information, and have arranged it in a very distinct manner. By using

Fig. 15. Moor Monkey.

this book, the young ornithologist will save much time, and gain his end more speedily than from any other similar work that we are acquainted with.

One cannot peruse Mr. Simmonds's book without feeling how truly we are wasting our substance in riotous living! Here is a work of above five hundred pages devoted to showing how materials may be utilized that we are in the habit of regarding not only as utterly useless, but many of them as deleterious. If "dirt is matter in the wrong place," then "waste" is profitable substances in the wrong place. No man in Great Britain is better able to deal with the important question of Waste Products and Undeveloped Substances," than Mr. P. L.

Simmonds; no other writer has devoted so much time and attention, or has for so long been regarded as an authority on these and kindred matters. If we had to find any fault with this most interesting, and what we regard as an important volume, it is that the vast store of material is not arranged under chapters or sections. We feel that such an arrangement would materially add to the value of the work. In a great measure, however, this is atoned for by a copious index. To the general as well as to the scientific reader, to the statesman and manufacturer especially, this book is invaluable. A word should be said as to its literary style. It is easy and attractive, and notwithstanding the overcrowding of facts, interests the reader instead of wearying him.

Mr. Cash's handsome little volume is just the book one would put into the hands of an unfledged naturalist. We know none other better able to speedily develop him. And to older readers it possesses many attractions, in setting before the world the simple but earnest lives of humble workers in the field of science. Here we learn how such "hobbies" can sweeten the most arduous toil, can render interesting the most monotonous of lives. With some of the characters here described, we were personally acquainted, and we can therefore testify to the accuracy of the author's delineations and observations. Some of these lives read like little idylls. Shut out from the great world that roars outside them, we find them looking to Nature for instruction, and studying her great kingdom with nevertiring zeal. The lives of such men as John Dewhurst, George Caley, Samuel Gibson (who went by the name of the "Scientific Blacksmith "), Richard Buxton (the author of the "Manchester Flora,"man who never earned a pound a week in his life!), George Crozier, Elias Hall, the geologist, and others of which this little book treats, read ambitious worldlings a lesson as to the real enjoyments they are constantly passing over. Most of the characters are Lancashire, for among the factory employés there is developed a genuine love of nature, and there may be found some of our best amateur botanists and entomologists. The book is pleasantly and earnestly written, and is a credit both to author and publisher.

-a

To notice such books as this first volume of the Telegraphic Journal is somewhat out of our usual line. But it is with pleasure that we can mention it as a most attractively got-up book, the subjectmatter as being various and important, and of a kind that must place the readers of such a periodical, au courant with all that is taking place in telegraphy in every part of the world.

"IN a man, a nervous or sensory impulse has been variously calculated to travel at 100, 200, or 300 feet a second."-Huxley's "Physiology."

A NEW ENEMY.

I WISH to say a few words about an enemy which

threatens to lay waste one of Europe's most valued esculents, the potato. For a long time North America has had to contend against two foes, which devoured the early shoots and leaves of the potato, and thus destroyed the hopes of the farmer and gardener. These were beetles belonging to the same family as the Blister-fly, and named Lytta atrata (or vittata) and Cantharis viniaria. They can be kept within bounds; but of late a third beetle has appeared among us which really

threatens to drive the potato out of cultivation altogether. It bears the name of the Colorado Potato-beetle (Doryphora decem-punctata); and should it once reach the Atlantic coast, and be carried unobserved across the ocean, then-woe to the potato-grower of the old country!

A man must witness the myriad legions of this insect, and the ravages of its never-tiring larvæ, in order to form an idea of the terrible danger with which Europe is threatened. For myself, judging from the tenacity of life exhibited both in its larval and perfect condition, I have not a doubt that it will soon overstep the bounds of North America, and make a home for itself in other lands.

Its true domicile is in the Rocky Mountains, where it feeds on a species of wild potato, Solanum rostratum (or Caroliniana). No sooner, however, had the edible potato (Solanum tuberosum) been planted by settlers at the foot of these mountains, than Doryphora attacked it greedily; the more largely its cultivation extended westward, the faster did its insect foe travel in an easterly direction, and scatter itself over the land. In the year 1859 it was located one hundred miles west of Omaha city, in Nebraska; in 1861 it showed itself in Iowa; in

1865, not only had it begun to devastate Missouri, but it had crossed the Mississippi in Illinois, everywhere leaving behind it flourishing colonies. In 1868 Indiana was visited; in 1870 Ohio and the confines of Canada were reached, also portions of Pennsylvania and New York; and its entrance into Massachusetts was notified. During the year 1871 a great army of these beetles covered the river Detroit in Michigan, crossed Lake Erie on floating leaves and similar convenient rafts, and in a very short time took possession of the country between St. Clair and Niagara rivers. Having got thus far, in spite of all efforts to stay their progress, there

is every reason to believe that before long we shall hear of them as swarming in the streets of New York and Boston (as they already swarm in the city of St. Louis), and then their passage across the Atlantic is a mere matter of time. Moreover, the beetle in its different stages is so entirely unaffected by the extremes of heat and cold, of wet and dry, which it has met with. here, that I have no doubt it will care as little for the changes of climate which occur in the temperate zone of Europe, and, once settled, will quickly become naturalized.

The devastations of the Colorado Beetle are all the greater, from the fact of its propagating itself with extraordinary rapidity, several broods following each other in the course of the year. The first batch of infant larvæ appears towards the end of May, or, if the weather be mild, of April. In fact scarcely has the potato plant shown itself above the ground, before the insect, which has been hybernating during the winter, also wakes to life. The female loses no time in depositing from seven hundred to twelve hundred eggs, in clusters of twelve or thirteen, on the underside of a leaf. Within five or six days, according to the state of the weather, the larvæ escape from the egg, and begin their work of devastation, which goes on for some seventeen days, when the little creatures retire below the soil, in order to undergo the pupal condition. After a delay of ten or fourteen days, the perfect insect comes into being, and the business of egg-laying commences anew. In this way, according to recent observations, three broods follow each other; the last, as just stated, wintering below the surface of the ground. No description can do justice to the marvellous voracity of this insect, especially in its larval state. When once a field of potatoes has been attacked, all hope of harvest must be given up; in a very few days it is changed into an arid waste-a mere mass of dried-up stalks.

At one time the cultivator indulged in the vain hope that Doryphora was a mere passer-by, that he would do his worst, and then move on, without becoming a permanent nuisance. Others, again, fancied that a hot summer and autumn, followed by a long drought in the ensuing year, tended to diminish its numbers. But it has been proved incontestably that the diminution was only due to the circumstance of many of the larvæ perishing, through being unable to enter the ground hardened

of the Solanaceous order, -the Egg-plant (S. melongena), the Tomato (S. lycopersicum), or the Wintercherry (Physalis viscosa). Indeed, in the northern parts of Illinois and in Wisconsin-incredible as it may appear it has established itself in the cabbage-garden as readily as in the potato-field. State of Illinois. FR. H.

CELLS FOR MICROSCOPIC OBJECTS.

continue the breed.

a popular instrument has rendered it desirable to mount objects as much as possible in their natural

Fig. 19. a. Colorado Beetle. b. Foot of ditt ditto. d. Wing-case, enlarged

Of the many nostrums that have b for the destruction of this beetle, shown itself to be of any value. I the plants with the highly poisono Paris green, a compound of arsenic copper. However, setting aside th inhaling this deadly mixture while spr the fields, there is the additional peril of the soil with it,-a peril which experi out at Washington have shown to be There remains, therefore, only the

picking, day after day, the eggs, larva, and beetle. But even this operation requires considerable care; for the juice of the crushed insect and its larvæ produces bladders and blisters wherever it comes in contact with the skin. If a wounded spot be touched by it, severe inflammation ensues, which is liable to pass into ulcers, and an application of it to the eye endangers vision to a very serious extent.

Fig. 17, on page 15, gives an idea of the Colorado Potato-beetle in its different stages. The eggs are of a deep orange-yellow. The larva on first emerging, are of a blackish hue, which passes quickly into a dark red, with a slight orange tint. On attaining their full size the colour varies between orange, reddish-yellow, and flesh. At c, fig. 18, is shown the pupa; at a the perfect insect, natural size; a foot is portrayed at b; a wingcase considerably enlarged at d. The ground colour of the latter is creamy-yellow (rahm-gelb), with five black longitudinal stripes, of which the third and fourth unite at the base..

Doryphora does not by any means confine itself to the potato. In places where that esculent is wanting, it will support itself on any other member

There are two ways in which paper cells may be made; one, by coiling it into cylinders and cutting off rings in the lathe, and the other, by "punching" rings out of flat sheets. The former serves well for all depths above the thickness of a sixpence, while the latter is most convenient for all others that are required to be of less depth, and may be adopted even for the thinnest writing-paper. The firstnamed plan, however, may be dispensed with, as rings of cardboard can be built up to any height with very litlle trouble or loss of time. The great difficulty hitherto has been in punching out these rings so as to get them of uniform width, that is to get one punch perfectly concentric with the other; but at length a "happy thought" occurred, that has rendered this dilemma" a thing of the past." It appeared obvious that, having punched out the interior of the intended ring, the placing of a kind of button in the aperture with a shoulder projecting beyond, and the exact width of the circle required, would guide the outer punch to its proper place and give us the hoped-for result, which it has done most completely.

The first step would be to provide a series of four or five punches of certain relative proportions, with

respect to each other. In the annexed diagram the three outer circles correspond with gun punches of the respective numbers indicated, but the two inner

10

.C

ones are shoemakers' punches

of a commoner description, --18 although answering the pur50 pose sufficiently well. The next step should be to obtain a series of brass cones of the form represented at A, B, fig. 19, one fitting into each of the punches except the smallest, while the projecting portion B should fit very accurately, and not too tightly, into the opening made by the punch. next smaller in size. Then commencing by punching out the smallest disc, the smallest guide-cone is next inserted and carefully fixed in its place, turning the card over so as to use the sharp edge of the aperture; the punch is lastly placed over this, which guides it to its place, when a sharp blow cuts out the portion required. The different sized rings being thus cut in succession leads to the least possible degree of waste in the material as well as saving in time. In the diagram the front of the outer punch C has been cut away to show the position of the cone in its interior and to give a clearer view of the arrangement and its action, DD showing the width or the resulting ring, which can be varied only by the relative proportions of the punches, which must he determined at the outset.

Fig. 19. Punches for making microscopical cells.

The next stage in the process will be to saturate them with varnish. Let a thin solution of shellac be made in rectified spirit of wine (or if cost be more a consideration than fragrance, methylated spirit may be used), and placing the rings in a widemouth phial, let them be covered with the solution and left so for two or three days closely corked up, when they will be ready to be pressed and dried. Having provided a few score pieces of common window glass about one inch square, let these be spread out on the table and the rings taken out one by one, placed upon them, one in the centre of each square, and then placing them one upon another with a spare piece of glass on the top, in a pile just sufficient to be taken up in the grip of a wooden American clothes-peg, which will thus act as a vice and squeeze them flat, and in which position they may be left until quite dry. I have a stout wooden box about one inch deep and five or six inches wide, partitioned off into compartments, a little over an inch wide, and these being filled with the glass squares containing the rings, a common wood screw is passed through the side opposite the centre of

the squares, which then screws the whole up into a compact mass with any amount of pressure. Of course any description of sized or unsized paper, parchment-paper, leather, or any other soft substance, may be cut in the same way, and will serve equally well when only dry objects are to be mounted in them; but when required for fluids, pure tin will be found one of the best materials for the purpose, especially as it can be cut in the same manner and with the same punches. This metal may be obtained of Stanton Brothers, in Shoe-lane, rolled to any thickness, at about half a crown per pound, half price being allowed for the spare clippings in exchange, so that but little loss will be incurred by waste. As this material, however, can hardly be cut conveniently of a thicker substance than about the thickness of a new shilling, glass has been resorted to in all such cases as require a deeper cell for the retention of fluids. To "punch" a hole through a piece of window-glass may seem a very unlikely proceeding, yet it is in reality one of very easy accomplishment. If the glass be securely cemented down with shellac upon a piece of brass not less than an eighth of an inch in thickness and having a hole in it of the size intended, the centre may be chipped out with a pointed hammer, in a very few seconds, and a rough file will then trim it to the edge of the brass, when it may be removed, and after soaking in liquor potassæ for a few hours to remove the lac, may be ground true, if greater perfection be desired. From the thinnest covering glass and plates a quarter of an inch thick, cells may be readily made in this manner.

The last point to be attended to is securing the ring firmly to the glass slip. If required for fluid, nothing answers so well as marine glue, taking care that all parts be sufficiently heated and well pressed together; but if only needed as dry cells, a far less troublesome process will suffice. For the circular tin and paper cells I have found no preparation so effective, or so little trouble, as "Priest's Diamond Cement." The parts to be put together should be warm and free from grease, and when metal is being fixed, the whole should be warmed up afterwards, to about the melting-point of the cement, as this keeps secure the attachment of the latter. For putting on covers it has too the merit of not "running in" while it holds the glass most effectually and is almost colourless. A thin coating of this upon all insecurely fixed cells, embracing the side and touching the cover at the top and the glass slip beneath, renders the whole perfectly secure by tying together, as it were, the cover and the slip, with the ring inside as a support. This cement may be purchased at any chemist's, price one shilling per bottle, holding about three quarters of an ounce, and is prepared for use by placing the phial for a few minutes in hot water.

MICROSCOPY.

CRYSTALS OF LIME IN THE PRAWN'S SKIN.The skin of the Prawn consists of three layers; between the outer and middle coats the crystals of carbonate of lime appear to lie. In a cast skin no crystals seem to be ever found, nor do any appear in a newly-formed skin. What then becomes of these crystals? Does the water dissolve them, or does the new skin absorb them in order to consolidate it? Perhaps some reader of SCIENCEGOSSIP may be in a position to answer the above.F. B. Kyngdon.

ON PRESERVING AND MOUNTING FRESH-WATER ALGE.-The fresh-water algae are not only beautiful but easily procurable, and would no doubt have received a much larger share of attention from the microscopist were their preservation as permanent objects possible. In the majority of instances, the beautiful colour and arrangement of the endochrome is destroyed by the death of the organism; there are some forms, however, which retain a considerable amount of their pristine beauty after having been mounted many years. The Nostocs are but little changed when mounted in fluid; and the Desmids, although losing their vivid green colour, retain their elegant outlines. The plan proposed by Dr. H. Wood for the preservation of the freshwater algæ, according to the author, has given the best results hitherto obtainable. After cleaning them, which he accomplishes in the following way : "The large filamentous ones may be washed by holding them fast on the slide with a bent needle or a pair of forceps, and allowing water to flow over them freely whilst they are rubbed with a stiffish camel-hair brush, or the mass of specimens may be put into a bottle half-filled with water and shaken violently, drawing off the water from the plants, and repeating the process with fresh additions of water until the plants are well scoured. I find, after trial of acetate of ammonia and various other media, that a very weak solution of carbolic acid is the best possible fluid to mount these plants in". the difficulty of securing effectually fluid-mounted forms induced Dr. Wood to try the following plan. He makes a solution of gum-damar in benzole, to which previously triturated oxide of zinc is added. This cement should be of such consistency as to flow freely from the brush. It will adhere if washed properly when the cell-cover is pressed down, even when glycerine is used as the preservative medium. Its advantage lies in the circumstance that the glass cover can be placed upon the ring of it whilst still fresh and soft, and that in drying it adheres to both cover and slide, so as to form a joint be

"A Contribution to the Natural History of the Freshwater Algae of America." By Dr. H. Wood.

tween them of the width of the ring of cement. The method of mounting with it is as follows:-A ring of it is made, by means of a "turntable," on a slide, which is put aside to dry. When required for use, the slide is again placed on the turntable, and a new ring of cement put directly over the old one. The specimen is immediately within the cell, and the requisite quantity of carbolated water added. The cover, which must be large enough to entirely or nearly cover the cement ring, is now picked up with the forceps, the under-side being moistened by the breath, to prevent adhesion of air-bubbles, and placed carefully in position. It is now to be carefully and equably pressed down with some force. By this any superfluous water is squeezed out, and the cover is forced down into the cement, which rises as a little ring around the edge. The slide may now be put aside to dry, or better, an outside ring of cement run round it in the usual manner. Unfortunately, the author does not state the length of time he has used this method. My experience of soft cements is that in a shorter or longer period they almost invariably run in, and I much fear gum-damar will not prove an exception.-F. K.

ON MOUNTING MICROSCOPIC OBJECTS.-We beg to draw the attention of our microscopic readers, who are always interested in anything relating to the mounting of objects, to the second edition of Davies's little book on this subject, which has just been issued by Hardwicke, Piccadilly. This edition is considerably enlarged; and, as its author was too unwell to see the sheets through the press himself, this edition has been edited by Dr. Matthews, to whom Mr. Davies handed over his additional notes, &c. A prefatory chapter has been added, and such extensions made as will introduce the book to a new class of readers-the medical students and practitioners. The editor has done his work well, and we can now confidently recommend this able little book as the cheapest and most comprehensive which the young miscroscopist can obtain.

BOTANY.

PLANT CRYSTALS.-Professor Gulliver, referring to his descriptions and figures of Raphides, Sphæraphides, and long crystal prisms, given in SCIENCEGOSSIP, May, 1873, continues his researches in a memoir, illustrated with a plate containing ten figures, in the Monthly Microscopical Journal, Dec., 1873. Of this last paper, the subject includes observations "on the crystals in the testa and pericarp of several orders of plants, and in other parts of the order Leguminosa." These crystals he names "short prismatic crystals," in order to distinguish them from the other and very distinct forms mentioned above. The short prismatic crystals are constantly