518 SUMMARY OF CURRENT RESEARCHES RELATING TO 



fore firmly connected with the frame 8. A cog-wheel, 11, is attached 

 to the micrometer-screw, and under it is the rod 15, one end of which 

 carries a small clutch which engages in the cogs. The apparatus 18, 

 consisting of a bent bar rotatory about a plug screw, 11), is attached to 

 the front part of the iron foot-plate. One end of this bar is set to the 

 divided scale, 17, and regulates the thickness of the sections : the other 

 end supports a vertical peg, 20. A similar vertical peg, 21, is set in the 

 base-plate, and is shown in fig. 135. When the crank G is rotated 

 towards the right, i.e. against the knife, the rod 15 at a certain moment 

 strikes against the peg 20, whereupon the clutch 15a is urged back 

 on the cog-wheel, the movement corresponding to the pre-arranged 

 section-thickness. In the leftward movement of the crank G the object- 

 carrier and object first pass the knife and then the bar 15 reaches the 

 peg 21 and must halt. The end, 15«, of the same bar is then, by the 

 further movement of the crank, pushed forward, and transfers its motion 

 by the clutch to the cog-wbeel 11, and so to the micrometer-screw. As 

 this latter is fixed at both its ends, the sleeve fastened on it is movable, 

 and is therefore slightly pushed upwards by an amount corresponding to 

 the adjustment on the scale. An endless band can be attached to the 

 instrument and made to receive the section-ribbon by rotating the 

 handle 27. Screws 2!) and 30 serve to slant the knife, a flat-ground 

 razor, as required. The nut in which the micrometer-screw engages 

 consists of two halves. If the knob 32 is rotated 90° then both these 

 halves are separated and the whole sleeve 9 can be raised or depressed ; 

 this arrangement is required at the commencement of operations so as 

 to bring the object into proper position for the knife. The scale is so 

 divided that the sections can be cut from 2 //. to 70 p. (even numbers). 



I (4) Staining and Injecting-. £< 



Staining Streptococcus mucosus.*— R. Hoffmann advocates the use 

 of Jenner's stain for detecting and studying this organism when 

 present in pure culture, or when associated with other organisms in 

 purulent or other discharges, and especially for use for clinical pur- 

 poses. Films are fixed and stained for two minutes in a methyl- 

 alcoholic solution of acid eosin and methylen-blue, washed in neutral 

 distilled water and dried. The bacterial body substance steins deep 

 blue, the capsule light blue, and the mucus, adhering to the outer 

 surface of the capsule, stains pale pink. 



Demonstrating the Nervous System of Ascaris.f — D. Deineka 

 finds that the methylen-blue-ammonium-molybdate method is the best 

 for staining the nervous tissue of Invertebrates, the procedures of Golgi 

 and Ramon y Cajal being quite useless. 



Demonstrating Nerve-terminations in Teeth of Mammalia. } — 

 W. J. Law highly recommends Bethe's method for odontt (logical work, 

 and gives the following description of it as varied for use with teeth : — 



" Small pieces of perfectly fresh tissue are fixed by placing upon 



* Centralbl. Bakt., lte A.bt. Orig., xlvi. (1908) p. 219. 



t Zeitschr. wiss. Zool., lxxxix. (1908) pp. 242-307 (11 pis. and 7 text figs.). 



X Proc. Roy. Soc. Medicine (Odontological Section) i. (1908) pp. 45-60 (7 figs.). 



