EXAMINATION OF FRESH TISSUES AND FLUIDS. 



95 



Fig. 5 1 shows a form of hand-centrifuge devised by Litten l and 

 Muencke of Berlin. The figure is reduced to ~ the natural size. 

 One revolution of the wheel R its teeth fit into the thread of the 

 vertical axis S causes 50 revolutions of the disc M with the 4 glass 

 tubes G. The wheel can readily be turned 100 times per minute, 

 .which gives 5000 revolutions per minute for the disc. Fig. II. shows 

 the disc in full rotation, and fig. III. the form of glass vessel used. 



By means of this instrument, corpuscles of light specific gravity, 

 such as blood-corpuscles, albumen, micro-cocci, as well as crystals, 

 e.g. oxalates, can readily be obtained in the form of a sediment, and 

 it is therefore especially useful for the investigation of the deposits in 

 urine and exudations. It is also very useful for obtaining tubercle 

 bacilli from sputum. 



Synoptical Statement. 



Processes required for Preparing a Specimen for Microscopic Ex- 

 amination, e.g., the Spinal Cord of a Dog or Cat (Garbkii). 



Cut the cord into pieces about 2 centimetres in length, wash them 

 in normal saline to remove all blood. Place them in 



1. Bichromate of potash (2 p.c.) 



Wash in running water 



3. Alcohol (50 p.c.) 



4. (70 p.c.) 



5. ,, (90 p.c.) 



6. ,, (absolute) 



7. In xylol or chloroform 



8. In paraffin on warm bath 



9. Embed in paraffin. 



10. Cut sections with microtome, and fix them on a slide 



with fixative. 



11. Remove paraffin by washing in toluol or turpentine, and 



then in absolute alcohol to remove essential oil. 



10 days 

 12 hours 

 i day 

 4 days 

 i day 

 i day 



12 hours 

 6-8 hours 



bb 



Harde 



| 



12. Place in 70 p.c. alcohol. 



13. Stain in strong carmine 



or hsematoxylin (5-15 

 minutes). 



14. Wash in water, then in 



70 p.c. alcohol, and de- 

 hydrate in absolute alco- 

 hol (5-10 minutes). 



I i 



to 



fl 



5 



3 



12. Place in distilled water. 



13. Pour on a few drops of 



the aniline dye (3-5 

 minutes.) 



14. Wash in water and then 



in absolute alcohol until 

 the section has the de- 

 sired tint. 



1 Deutsch. med. Wochensch., No. 23, 1891. 



