56 THE AMERICA:N' MONTHLY [March, 



San Francisco, Cal. — E. J. Wickson, Secy. 

 /an. 12, 1888. — A friendly letter was read from the Microscopical Society of Welles- 

 ley College. 



Professor H. G. Hanks read a paper on ' Pectolite ' — a hydrous silicate of lime and 

 soda. This mineral was discovered in 1828, and described by Von Kobel, who gave 

 it the name signifying 'Combstone,' indicating its peculiar structure. The mineral 

 is rather rare, having been found at but about eight localities, until its recent discovery 

 in California. Pectohte has several varieties, which Professor Hanks described. The 

 first notice of it was given in the ' Fourth Report of the California State Mineralo- 

 gist.' C. H. Aaron found a single doubtful specimen in a bowlder at the foot of 

 White Mountain in Mono county. In the early part of 1887, a beautiful translucent, 

 nearly white rock was discovered in Tehama county, which was pronounced pecto- 

 lite by Prof. W. P. Blake. 



The specimen was recently received from George Senn, who brought it from Santa 

 Barbara under the impression that it was asbestos. It was found in a mining claim 

 owned by John C. Keyes, where it occurs in large quantities and could be taken out 

 by the ton. The microscopic character of the material was noticed. When handling 

 it considerable annoyance was experienced from the prickly nature of the minute 

 spicules or acicular fibres that enter the flesh like nettles. Being very sharp and 

 small, they can only with difficulty be extracted. The microscope showed why this 

 effect was produced. Each slender crystal breaks in a direction oblique to its sides, 

 and this peculiarity of cleavage produces the keen-pointed needles that so easily 

 penetrate the flesh and skin. 



Dr. Fredericks, of New York, gave an account of his mineralogical studies in South- 

 ern California. He reported finding kyanite at Carga Muchacho gold mines in San 

 Diego county, near Fort Yuma. He remarked the resemblance between the occwr- 

 rence of minerals at this location to that of Manhattan Island. 



Dr. Douglass Montgomery gave a lecture on the nature of cancerous growth, illus- 

 trating his remarks with blackboard drawings and microscopic preparations. He 

 pointed to the layers in which the malignant growth originates, traced its course, and , 

 pictured its effects. 



J. G. Clark exhibited a slide of the Edge Hill diatomaceous material donated by 

 WiUiam Irelan of the Mining Bureau. The earth was seen to contain only the com- 

 moner forms. 



A very interesting object was a slide of marine polyzoa, containing small corals. It 

 was mounted by F. L. Howard out of materials received from Australia. 



Washington, D. C. — E. A. Balloch, Secy. 



Dec. 2/, 1887. — The 70th meeting. An e.xhibition of preparations and an informal 

 discussion of methods of mounting was had. Prof. Seaman described a plan of 

 showing multiple images in the eyes of insects as follows : — Upon a piece of card-board, 

 large enough to cover the mirror, make a cross with black ink, each of the four arms 

 of which may be about half an inch long by one quarter inch broad. Clamp this pa- 

 per over the upper surface of the mirrror and reflect the light from the paper to the 

 lower surface of the slide, containing the preparation of the insect's eye. It is, in fact, 

 simply a substitution of the card-board for the mirror. 



Prof. Seaman showed an ingenious device for cementing the Pierce cells to the glass 

 shps. In response to an inquiry for a good shellac cement he gave a formula from 

 which he had secured the best results. (See page 53). 



Dr. J. M. Lamb showed slides of tissues from the AmpJiimua, noted for the ex- 

 aggerated size of all its histological elements. Double stainings of the blood corpuscles 

 of this amphibian were particularly interesting. 



Mr. Chapman said that he had been trying to mount some of the mosses sent out 

 in the ' Ward ' packets, but had met with considerable trouble owing to the difficulty 

 of getting rid of the air contained in the specimens. As a last resort he had boiled 

 them, dehydrated with alcohol, passed through oil of cloves, "and then mounted in 

 balsam. 



This society will hold its annual soiree- in April next. 



Essex County, N. J. — F. Vanderpoel, Secy. 

 Dec. IS, '87. — At the meeting held at the residence of Mr. Geo. S. Woolman, Orange, 

 N. J., Dr. Allan exhibited some slides illustrating caries in teeth, both natural and ar- 



