I. THE ESSENTIAL NATURE OF LIVING MATTER 

 IN ITS SIMPLEST FORM. 



1. OBJECT. To learn something of the essential nature of 

 living matter (protoplasm). 



2. METHOD. Take a very simple form of living matter 

 the yeast plant and place it under various conditions. Place 

 a small quantity of yeast on a slide, and add a drop or two of 

 water. Rub up into an emulsion with a glass rod, and transfer 

 a little on the end of the rod to : (A) a test-tube of a 

 solution containing the chemical elements in the yeast, e.g. 

 urea CO(NH 2 ) 2 , glucose CyH^O,,, with traces of sodium phos- 

 phate Na 2 HP0 4 , potassium sulphate K^SO^ and calcium 

 phosphate Ca 3 (P0 4 ) 2 ; (B) a test-tube filled with water. 



See that the tubes are quite full. Shake well and examine 

 a drop with the microscope, and make a rough estimate of 

 the number of torulse in two or three fields of the microscope. 

 Draw one or two torulae. 



At each Bench 



Students at places 1 and 2 at once insert the corks firmly 

 into the tubes. The tubes of 1 are placed in an incubator at 

 37 C. The tubes of 2 are placed in a vessel of broken ice. 



Students at place 3 introduce a few drops of phenol solution, 

 insert the cork, and place the tubes in the incubator. 



Students at place 4 boil the tubes before quite filling them, 

 cool them under the tap, fill them with water, insert the corks, 

 and place them in the incubator. 



3. RESULTS. (A) ON YEAST. Next day the tubes are to 

 be examined with the naked eye before and after shaking, and 

 the condition of each tube studied, contrasting it with the 

 condition on the previous day. A drop of the fluid after 

 shaking is to be examined with the microscope, and the number 

 of torulse in two or three fields to be estimated. 



