1880.] 



MIOEOSCOPKJAL JOURNAL. 



219 



"24 slides of botanical specimens, which 

 will certainly prove to be very useful for 

 both private study and class-demonstra- 

 tion. Among them we find the following : 

 protoplasm and nucleus in cells of Cypri- 

 pediuvi pubisccns, pitted cells, annular, 

 sj)iral and scalariform vessels in different 

 stems, medullary rays, lactiferous tissue, 

 glandular hairs, oil-glands, chlorophyll- 

 grains, aleurone (protein grains), cysto- 

 liths, raphides, etc. The price of the col- 

 lection, in a neat case, is only $1.5. The 

 same firm are the authorized agents in 

 this country' for the English Mechanic 

 and World of Science, a veiy excellent, 

 \seekly periodical, which costs $3.25. 



— The mechanical stage movements 

 will probably always be in favor with those 

 who are accustomed to them, but we 

 believe that most workers with the mi- 

 croscope prefer the simple glass object- 

 carrier. However, it is sometimes im- 

 portant that a certain space should be 

 examined ver\- thoroughly, and for this 

 purpose, some mechanical movements 

 seem to be necessary, if we mav judge by 

 the results of some experiments by a 

 German investigator, which may be sum- 

 marized as follows : — 



With magnifications of 50, 100 and 200 

 diameters, the field of view is respectively 

 about 2"""-, 1"""-, and >^"""- in diameter. 

 Hence, to examine every particle on a 

 surface of one square-inch would require 

 that the object should be moved, for the 

 different powers 350, 700 and 1,400 times. 

 A square-foot was marked with numbers 

 from 1 to 1,000, and photographed upon a 

 slide in squares of respectively 1, yi and 

 X-inth. These photographs were exa- 

 mined in the usual way, noting the num- 

 bers that came into the field of view. It 

 was found that about 300 ])er cent, of the 

 numbers were not seen at all, while on 

 the other hand, a large number of them 

 were seen two and three times. 



— The Specialist and Intelligencer, is 

 a new monthly medical publication, " de- 

 voted specially to the publication of ori- 

 ginal and selected articles on diseases of 

 the eye, ear, throat and skin, venerial di- 

 seases, etc., and to a complete record of 

 medical literature. The Editor is Charles 

 W. Dulles, M. D., of Philadelphia. The 

 Intelligeftcer has been merged into this 

 new journal. Published by Presley Blakis- 

 ton, 1012 Walnut Street, Philadelphia. 



— We have seen some of' the rubber 

 cells which are described on another 

 page ; they are very neat in appearance 

 and deserve to be used quite generally by 



microscopists. They cost but thirty cents 

 per dozen, and can be obtained from 

 most dealefs in microscopical goods. 



MICROSCOPICAL SOCIETIES 



ILLINOIS STATE. 



The regular meeting was held on Fri- 

 day evening, October 8th. The President, 

 B. W. Thomas, in the chair, Mr. W. H. 

 Bulloch described a new stand which he 

 had recently constructed, designed espe- 

 cially for lithological work, but which can 

 readily be converted into an instrument 

 suitable for ordinary work. The speaker 

 stated that he used the adjective new 

 with considerable hesitation, as his claims 

 in that direction had, in the past, been so 

 strongly disputed. Some features were, 

 however, new to him ; these, he proceeded 

 to describe. The stage was made to ro- 

 tate concentrically on the plan adopted 

 in his large instruments, and was grad- 

 uated to read with a vernier to minutes. 

 Both the mirror and substage were 

 mounted on graduated circles, and ar- 

 ranged so as to swing over the stage, 

 either separately or in unison. The sub- 

 stage was made in two cylindrical fittings. 

 The lower one, cairying the polarizing 

 prism, could be readily swung to one 

 side, while the upper carried the achro- 

 matic condenser. The polarizing prism 

 was mounted with a circle graduated to 

 degrees, and was fitted with a stop for 

 marking the position of the prism. The 

 analyzer was mounted above the object- 

 ive somewhat after the manner of a Wen- 

 ham prism, and could be slid in and out 

 of position with the same facility, and 

 also carried, if desired, a quartz film. The 

 stand was also provided with a goniome- 

 ter eye-piece. 



Dr. Detmar exhibited sections of animal 

 tissue, which, he claimed, were but 1-1500 

 inch in thickness, and briefly described 

 the instrument used in cutting them. Mr. 

 Beck, of London, who was present, sug- 

 gested that some of the surplus American 

 ingenuity of the members might advan- 

 tageously be expended in inventing a sec- 

 tion-cutter for diatoms. 



The Secretary illustrated his method of 

 mounting balsam slides. By the use of 

 very hard balsam contained in a chemist's 

 dropping bottle, a slide could be finished 

 in a few minutes, ready for the cabinet. 

 He also called attention to a peculiar al- 

 goid growth which had made its appear- 

 ance in his apparatus for making diali/ed 



