40 JOURNAL OF THE [july, 



thrust, and that these cutting instruments might be more appro- 

 priately termed rasps than saws. 



Mr. C. S. Shultz presented to the Cabinet of the Society two 

 slides of Diatoms, prepared by Miss M. A. Booth. 



This being the last meeting before the summer recess, the 

 President wished for the members a pleasant vacation, and a 

 safe return to the operations of the Society, and urged upon 

 them the duty and advantage of the prompt commission to 

 writing, and the preservation of some notes of their microscopi- 

 cal vacation experiences. 



OBJECTS EXHIBITED. 



1. Stage Micrometer — in squares — upon Speculum metal : 

 exhibited by Chas. S. Shultz. 



This was ruled by Prof. Wm. A. Rogers, upon his dividing 

 engine, in two sections ; in one the divisions are parts of an inch, 

 in the other, parts of a millimeter. Much longer ruled microm- 

 eters on metal, of which the error of the ruling of each division 

 has been fully investigated, are now used as the standards of 

 measure for the accurate construction of tools and machine work. 



These measures are placed upon instruments known as Com- 

 parators, each of which has two reading microscopes with eye- 

 piece cobweb micrometers. The objectives are provided with a 

 Tolles* vertical illuminator, so the divisions on the micrometer 

 appear very black. The system is so practical that mechanicians 

 are able to work within an error of ssvws of an inch. 



2. Triceraiiiim Javanicum : exhibited by Chas. S. Shultz, 



3. Section from Scalp of White Collared Monkey : exhibited 

 by Chas. S. Shultz. 



4. Albany City Water : exhibited by P. H. Dudley. 



5. Eye-piece micrometer, made by Mr. Chas. Fasoldt : ex- 

 hibited by P. H. Dudley. 



The lines are said to be ground in the glass, not ruled. 



6. Spores of Meruliiis lachrymans, Fr., from Hartford, Ct.: ex- 

 hibited by P. H. Dudley. 



This fungus is the one which often causes the so-called '* dry 

 rot " of houses, especially those of pine wood. It is commonly in 

 the form of a placenta, but also effuso-reflexed. The forms are 

 from two inches to thirty in diameter. The hymenium is pul- 

 verulent, and throws off great numbers of spores — those thrown 



