APPARATUS, MATERIAL, AND REAGENTS. 23 



Cylindrical glasses graduated in cubic cen- 

 timetres, 10 ccm., 100 ccm., 500 ccm., are 

 required for measuring the liquid ingredients of 

 nutrient jelly, and also in preparing the various 

 staining solutions. 



A large wide-mouthed glass jar, with a glass 

 cover, is extremely useful. It must be padded 

 at the bottom with cotton wool for containing a 

 stock of tubes of sterilised nutrient jelly, and 

 should be placed within reach on the working 

 table. 



Balance and Weights. A balance, with 

 large pans and set of gramme weights, is con- 

 stantly required. 



Cotton Wool. The best or " medicated " 

 cotton wool should be procured. 



Gelatine. The gelatine for bacteriological 

 purposes must be of the very best quality (gold 

 label). 



Agar-Agar. 7'his is also called Japanese Isin- 

 glass ; it consists of the shrivelled filaments of 

 certain Algae (Gracilaria lichenoides and Gigartina 

 speciosa).^ 



Peptonum Siccum (Savory and Moore). 



Table Salt. Prepared table salt can be ob- 

 tained in tins or packets. 



Litmus Papers. Blue or red litmus paper in 

 cheque books, for testing the gelatine mixture, 

 etc. 



* Ilueppe, Die Methoden der Bakterien Forschung. 1885. 



