1889.] MICKOSCOPICAL JOURNAL. 139 



were a gigantic tarantula spider, several gorgeous members of the Pa- 

 pilio genus, fierce-looking dragon-flies, beetles, wasps, and a large col- 

 lection of small objects. 



The advisability of holding an annual reception was discussed, and a 

 motion favorable to the pi'oposition carried, the details to be arranged in 

 the near future. Dr. Harkness made some excellent remail<;s bearing 

 on the subject of mici"oscopical receptions here and in Europe, which 

 were listened to with pleasure, and will probably be stored away in 

 the memory of the prospective committee of arrangements. 



The acquisition to the library consisted of the usual miscoscopical mis- 

 cellany, while the cabinet was increased by a fine slide of Mentzelia 

 from Colorado, donated by Mr. Leckenby. 



April 2^, 1889. — The regular meeting was held at the rooms. 120 

 Sutter street. President Payzant presiding. A fine series of photographs 

 was exhibited, containing some graphic enlargements on the new East- 

 man bromide paper. This process of enlarging on bromide paper, 

 though quite recent, is very popular and produces excellent results, the 

 effect, when exposure and negatives are properly manipulated, being 

 almost equal to steel engraving. The bromide process commends itself 

 to those interested in photo-micrography by its simplicity compared v/ith 

 the tedious work of printing from silver paper. 



Mr. Lickenby occupied most of the evening in concluding his prac- 

 tical demonstration of preparing and mounting insects in balsam. It 

 is quite difficult in preparing many of the smaller forms of insects to 

 remove the debris from the surface of the specimen without injuring the 

 delicate portions. This the gentleman accomplishes by the aid of albu- 

 men, flowing the white of an eg<g over the object and immersing the 

 slide in hot water till the albumen is coagulated, when it will generally 

 crack open, and may be removed in two portions, carrying with it all 

 the foreign matter and leaving the surface of the specimen perfectly 

 clean. Another thing strongly advocated is thorough washing of the 

 objects in running water, and a final rinsing in either filtered or distilled 

 water before placing in alcohol. In mounting, the insect is placed under 

 the cover-glass arranged in proper shape, the clearing solution applied, 

 and when sufficiently transparent the oil of cloves is drained away and 

 Canada balsam introduced at one edge of the cover-glass, the slide be- 

 ing held over the flame of a lamp to gently warm the balsam and allow 

 it to flow in and displace the remaining oil of cloves. No annoyance 

 need be felt at the presence of bubbles of air, as they will gradually, dis- 

 appear. The mount when filled with balsam is placed in a warm oven 

 or incubator and kept at a temperature of from 120° to 130° Fahrenheit 

 for twenty-four hours, when the balsam will be thoroughly hardened 

 and all the air bubbles driven out. Mr. Lickenby does not advocate the 

 use of volatile solvents with balsam, he being convinced that a certain 

 amount of gas is always retained in the mount in a latent state, requir- 

 ing only a slight amount of heat to pi'oduce bubbles and disfigure the 

 specimen. The outer skeleton of insects is composed of a substance 

 called chitine, which is quite unique in its chemical composition. It 

 appears to be, within certain limits, very resistant to acids and alkalies, 

 and it is owing to this fact that caustic potash can be used in such varying 

 proportions in treating them for microscopical study. It is said, how- 

 ever, that chitine succumbs to the action of chlorine compounds, which 



