632 SUMMARY OF CURRENT RESEARCHES RELATING TO 



further experiments with Hesse's tubes, both on the roof of the Science 

 Schools and in the interior of buildings. 



To obviate the melting of the tubes in hot weather they were wrapped 

 in bibulous paper saturated with water, and this was surrounded by tissue 

 paper. 



In the open air the number of micro-organisms increases with the tem- 

 perature ; thus in January, with temperature of 3 • 5° C, only four colonies 

 (average) per 10 litres of air were obtained, whilst in August, temperature 

 18*3°, as many as 105 colonies were found. 



In the interior of buildings the same result as in the previous com- 

 munication was arrived at, viz. that micro-organisms are more numerous 

 when the air is disturbed than when no movement is going on. 



A table of results and a table of curves formulating the results conclude 

 the paper. 



MICEOSCOPY. 



a. Instruments, Accessories, &c.* 

 (1) Stands. 



Jaubert's Microscopes, Eye-pieces, Objectives, &c. — One of the 



most extraordinary patents on the file of the Patent Office f is certainly 

 that of M. Leon Jaubert for " Improvements in Optical Instruments." 

 Five large sheets, 27 by 19 inches, are filled with 189 figs., 125 of which 

 illustrate his ideas of improvements in both Monocular and Binocular 

 Microscopes and describe objectives and eye-pieces of special arrangement 

 made of concentric layers of glass united in groups, multiple objectives, 

 revolvers for eye-pieces and objectives, a rotary micrometer, prisms, and 

 other similar matters. We have selected the following as sufficiently 

 showing the patentee's views, and if more information is desired the specifi- 

 cation of the patent is available in the Library. 



Universal Microscope. — This is copiously illustrated in all its parts in 

 the Specification, but we give in preference (fig. 155) a modern form of the 

 Microscope, as actually constructed by the patentee and recently exhibited 

 by him. It has an oval base S, supporting two pillars C, which are bent 

 towards each other at the upper ends, so that the trunnion or inclining 

 axis 4> is much smaller than usual ; a spring-catch / engages in a series of 

 holes in the socket A of this axis to fix the various positions of inclination. 

 A second axis is applied in front of A to provide lateral inclination of the 

 stem B, carrying the arm B', the body-tube T, the stage P, the mirror 

 G, &c.; a spring-catch r fixes the position by means of a series of holes 

 shown on the collar. The stem B has a rack on either side on which acts 

 a screw-collar E, raising or lowering it in the socket A'. A similar 

 mechanism is applied to the body-tube for the coarse-adjustment actuated 

 by the screw-collar E' with a slow movement by the screw-collar E^, A 

 third screw-collar at E^ focuses the micrometer in the eye -piece. The fine- 

 adjustment has two rates of motion by the milled heads V and V. The 

 substage H is provided with a fine-adjustment actuated by the screw-collar e^ 



We have not attempted to give the full description of the patentee, but 



* This subdivision contains (1) Stands; (2) Eye-pieces and Objectives ; (3) Illumi- 

 nating and other Appaj-atus ; (4) Photo-miciography ; (5) Microscopical Optics and 

 Maniimlation ; (6) Miscellaneous. 



t 18(36, No. 47i^, 14th February. Of. also Les Sciences, i. (1S83) pp. 55-7 (3 figs.), 

 and pp. 9, 11, 31, 40, 62-3, 78, and 109. 



