1896.] MICROSCOPICAL JOURNAL. 283 



lucent, when it can be mounted on a slide, enclosed in a 

 cell, if thick, or sourrounded by bits of glass, the sup- 

 erfluous oil removed as far as possible with a bit of 

 blotting paper and replaced with Canada balsam which 

 has been dried and dissolved in benzole or chloroform. 



b. jSections. — Sections are made from objects which 

 have first been preserved according to the method given 

 above or some kindred method. The tissues to be sec- 

 tionized may be held in the hand or in pith, in which 

 case the very sharp razor blade is well flooded with alco- 

 hol and as thin a slice as possible is cut and floated ofi" 

 into a glass disk. It is then put through the course 

 given above. 



A finer method for section cutting, giving the finest 

 sections, but only possible after considerable experience, 

 is that of embedding the object in parafiine. The steps 

 in this process are as follows, the object already ade- 

 quately preserved and stained as described above and 

 thoroughly dehydrated by passing through absolute ab- 

 solute alcohol is : (1) Soaked in chloroform (or turpen- 

 tine or cedar oil) till the alcohol is thoroughly removed 

 (t) to 12 hours), then transferred to a solution of parafiine 

 in the same kind of oil for an equal time ; removed thence 

 and soaked in pure parafiine melted in a bath over steam 



The heat in this bath must not reach 60° C. Should be 

 only sufiicient to barely meet the parafiine. When the 

 last traces of chloroform (or other oil) are completely, 

 driven off by heat the specimen is placed in a mould and 

 surrounded by melted paralBne which cools and hardens 

 around it. Sections cut from this are run through tur- 

 pentine to dissolve the parafiine and mounted in Canada 

 balsam. 



Whooping Cough Bacillus. — Kourlov has been invest- 

 ig-ating- the saliva of whooping cough patients, and has 

 found in every case and in them alone, a certain special, 

 spore-forming, ciliated amaeba, which he suggests may be 

 the cause of the disease. — Bulletin Medical. 



