13S THE AMERICAN MONTHLY [June, 



jected spleen, epithelioma of the lip, al)scess of the kidney, and cervix 

 uteri in anteflexion. 



Mar. 12. — Dr. Trowbridge presented the subject of " Addison's Dis- 

 ease," illustrating it by sections taken from a recent case, including skin, 

 supra renal capsule, and kidney. Brown pigment occupying the cells 

 of the rete malpighii, and the usual appearance of tubercular matter in 

 the supra renal capsule were very beautifully demonstrated. The kid- 

 ney showed a small pus cavity (tubercular?) in one of the pyramids, 

 and numerous small points of round-cell infiltration in the adjacent kid- 

 ney substance. 



San Francisco, Cal. — C. P. Bates, Secy. 



April lo, 1889. — The announcement of a paper by A. B. Leckenby 

 on the preparation and mounting of insects resulted in a large attend- 

 ance. Mr. Leckenby spoke briefly of the difficulties experienced in 

 manipulating the numerous forms of insect life for slide-mounting and 

 lantern-projection. The method pursued by him embodies the result 

 of many years' labor. 



Starting with the Coleoptera^ or beetle family, the first step is to de- 

 vitalize them quicklv and while they are in tiight, which he accom- 

 plishes by dropping them through a long glass tube into boiling water. 

 The elytra and wings are by this means immovably fixed in the extended 

 position, and remain unaltered during the subsequent operations. The 

 body of the insect is then injected hypodermically with a strong solu- 

 tion of caustic potash and allowed to remain three or four hours, then 

 transferred to a glass slip and gentle pressvu'e applied, when the viscera 

 and other tissues forming the interior of the body will be expelled. To 

 dehydrate or remove the watei-y portion absolute alcohol is generally 

 recommended, but the lecturer contended that it was expensive and not 

 always at hand, while equally good results would follow by placing an 

 ounce or two of refined gelatine in a vessel, pouring on alcohol of 95 

 per cent., and immersing the object for a short time — the gelatine, from 

 its affinity for water, absorbing that fluid from both the object and al- 

 cohol. The insect is then placed in oil of cloves to clear or render it 

 transparent, and is ready for mounting permanently in balsam. Bvthis 

 method the insect is rendered entirely transparent, the peculiar geomet- 

 rical markings of the wings, the abdominal and thoracic rings, and the 

 various parts forming the head and limbs are beautifully displayed. 



In preparing the Lepidoptera a somewhat difl'erent course is pur- 

 sued, as the wings of all butterflies and moths, being covered with 

 easily detached scales, must be protected. The butterfly or moth is 

 placed on a square of glass and liquid parafiine flowed carefullv over 

 the entire insect. After cooling, a small aperture is made, exposing a 

 portion of the body, and caustic potash injected ; the subsequent oper- 

 ations being the same as for beetles, excepting that sulphuric ether must 

 be used to dissolve oft'the parafline, leaving the soft velvetv coveringof the 

 wings unimpaired. In this manner are prepared the beetles, dragon- 

 flies, bees, wasps, caterpillars, etc.. and when mounted in balsam they 

 form some of the most beautiful and instructive objects imaginable, 

 whether viewed through the microscope or projected on the screen. 

 Mr. Leckenby exhibited many fine specimens, noticeable among which 



