Fig. 6.—Home-made Dissecting Microscope.
This modest little instrument generally stands on my work-table, and has provoked some remark and a little good-natured banter from friends who have seen it. Nevertheless, I should be sorry to part with it, for I have found it extremely serviceable in many ways. And more than one critic has had to confess that better results were obtained than one would expect from its appearance. The total cost out of pocket was, 3d. for the box, 3s. for the lens, and 1d. for the plate-glass, while the man who made the pillar and ear-piece would take no more than 6d. for his work. This brings the total to 3s. 10d. With a little ingenuity the pillar might be made to carry a collar, and so take a Steinheil lens. This would swell the total cost to about 11s.
Other apparatus need not be costly. An incident occurred at the meeting of the Quekett Microscopical Club on November 22, 1878, which shows how readily common objects may be utilized for our purpose. The late Right Hon. T. H. Huxley, who was at that time President, exhibited, and made some remarks on, the dissecting microscope which now bears his name. During the discussion which followed, Professor Charles Stewart exhibited some little saucers, which were admirably adapted for dissecting purposes. The President said that he should ‘be glad to know where these convenient little saucers could be obtained.’ The next paragraph of the minutes is interesting and instructive. ‘Mr. Stewart said they were to be found at the corners of the streets, containing three whelks or three mussels for a penny. He bought those he had brought to the meeting at a shop in the New Cut, where they were supplied to costermongers[4].’
As very many of the objects with which we are concerned are aquatic, we shall want vessels of some sort to serve as aquaria. Any glass vessel will answer our purpose, provided it is clear, to allow of the examination of our captives; or shallow pie-dishes may be utilized. The glass pots in which preserves are sold will do admirably, and any glazier will cut us covers for a few pence. Within reasonable limits, the smaller the aquaria are the better. The inmates can be seen more easily, and picked out with less trouble when one wishes to examine them.
The principles on which aquaria should be kept are now pretty generally understood. There should always be a small quantity of growing aquatic vegetation, and a supply of minute life to furnish food for the larger forms. Excess of light should be avoided, and the temperature should not be allowed to rise much above 50° F. Carnivorous beetles and their larvae may be fed with small pieces of meat, small garden worms, or tadpoles. Most of the smaller larvae treated of will be satisfied with vegetarian diet, varied with an occasional meal of water-fleas.
Fig. 7.—Beakers.
Fig. 8.—Glass Capsule.
If one cannot lay the household stores under contribution for jam-pots, tumblers, and bottles, beakers (Fig. 7) make capital small aquaria. They are sold in nests, and may be had either rimmed or lipped—rimmed for choice. There is no difficulty in obtaining them of any optician or glass-merchant. Mine have been bought from Messrs. Beck, of Cornhill, as have the capsules, &c., figured here.