HARDWICKE'S SCIENCE-GOSSIP. 



275 



New Mode of Mounting Opaque Objects. — 

 At the recent meeting of the Microscopical Section 

 of the American Association for the Advancement 

 of Science, Prof. H. L. Smith described his new 

 method of mounting opaque objects, where it is 

 desirable to cover them with thin glass. He takes 

 a circular disk of thin sheet wax, which is easily- 

 cut with a punch from the sheet wax ordinarily 

 used for making flowers, and attaches it by means 

 of heat to the centre of a glass slide. A brass ring, 

 of which the interior is the same size as the disk, 

 is then attached to the slide, and the object is fixed 

 to the wax by slightly moistening the surface of 

 the latter by a minute drop of turpentine. When 

 dry, a cover which exactly fits into the bevel of the 

 ring is attached with a little cement, and the whole 

 may then be finished off on the turntable. The 

 appearance is very elegant, and the specimens are 

 perfectly preserved. 



Double Staining of Muscular Tissue with 

 Picric Acid and Carmine. — In the American 

 Journal of Microscopy George D. Beatty, M.D., 

 writes to call attention to the muscular tissue of 

 the tongue of the Lissotriton punctatus, the smooth- 

 skin newt, and of the Amphiuma tridactylum, and 

 to describe a mode of double staining with picric acid 

 and carmine that is well known. " The muscular 

 tissue of these two species of the order Urodela is 

 deserving of notice on account of the well-marked 

 transverse striae, and very large sarcolemma cells 

 or nuclei. These nuclei in the Lissotriton are oval ; 

 in the Amphiuma they are oval, but often very much 

 elongated, some of the latter extending one-third 

 across the field on using a one-fifth objective and 

 A ey*epiece. In staining with picric acid and car- 

 mine, the carmine is appropriated by the nuclei, 

 while the picric acid is taken up by the sarcous 

 elements aud the perimysium. Picric acid causes 

 the transverse striae to come out more distinctly 

 than any other dye. The tissue should be hardened 

 by first putting into 95 per cent, alcohol, and after- 

 wards absolute alcohol. Transverse sections are 

 best obtained by cutting in a section machine ; 

 longitudinal fibres by carefully teasing out with 

 needles before staining. The process of staining is 

 as follows : — Remove the sections or small shreds 

 that have been teased out to 25 per cent, alcohol 

 for one minute. Place in Dr. J. J. Woodward's 

 borax carmine for five minutes. Soak about ten 

 minutes in alcohol acidulated with 20 per cent. 

 of hydrochloric acid. This will in great part remove 

 the carmine from other parts than the nuclei. Wash 

 in alcohol for fifteen minutes to remove acid, 

 changing the wash once or twice. Pat for thirty 

 or sixty seconds into an alcoholic solution of picric 

 acid, one-twelfth of a grain to the ounce. Wash in 

 alcohol, and put into absolute alcohol for fifteen 

 minutes, and oil of cloves for the same time. 



Mount in balsam. Other parts of the Amphiuma 

 than the tongue afford beautiful muscular fibre, but 

 with fewer nuclei ; indeed, this batrachian is a 

 microscopical treasure all through, as is our aqua- 

 rium friend, the graceful Lissotriton. I am indebted 

 to Dr. Christopher Johnston for the Amphiuma 

 material I am fortunate in possessing." 



ZOOLOGY. 



The Slow-worm. — I have nowhere seen any 

 account of the Slow-worm {Anguis fragilis) having 

 brought forth its young in confinement, and have 

 no doubt but some of your readers will be interested 

 to know that I have this season had two broods, 

 the parents having been in my possession about 

 two years. Last season they produced young ones, 

 but all were dead at birth, or must have died soon 

 after, as they had not freed themselves from the 

 thin skin-like shell in which they were coiled. This 

 season they had emerged from the eggs when I 

 found them, and could not have been many hours 

 old at the time. They are now several weeks 

 old, very lively and healthy, having grown about 

 half an inch since their birth, and are a little 

 more than three inches long, of a beautiful silvery 

 greenish-grey on the back, having a dark line run- 

 ning from opposite the eyes, where it is slightly 

 forked, to opposite the vent ; the belly is black and 

 glossy. In shape they only differ from the adults 

 in the head being broader in proportion, slightly 

 protruding opposite the eyes and jaws. Their food 

 is caterpillars and grubs, particularly the smooth 

 kinds. Like all my pets, they are tame ; and my 

 method of taming all creatures is to handle them 

 freely, pet them, and on no account to punish them 

 in any way; give them food at regular intervals, 

 study their peculiar habits, and indulge them in 

 anythiug you find they take pleasure. By this 

 means I have had the chameleon, toads, mice, rats, 

 birds of various kinds, and, perhaps, the most un- 

 promising of all— a Lepidosiren (or Mudfish) — take 

 their food from my fingers quite freely. At one 

 time I was under the impression that such things 

 were attracted by their food alone, and merely had 

 to overcome their natural timidity, but I am now 

 quite convinced that is not the sole attraction, — 

 that there is an amount of affection, liking, or what- 

 ever you may please to term it, which, when once 

 obtained, they will refuse their food to obtain your 

 caresses. This was particularly the case with a 

 chameleon I had in my possession about two years, 

 and is the case with birds and a rat I have at this 

 time. The latter is delighted at all times to leave 

 its companions and mount my shoulders. When on 

 the ground, at the slightest alarm, it darts to my 

 feet and scales the heights to its favourite security, 



