REPORT OF COMMITTEE ON DESCRIPTIVE CHART 133 



mixed with sterile water and heated to 85°C. for ten minutes; if 

 still alive, spores may be regarded as unquestionably present. 

 Also make repeated transfers of the culture onto agar and exam- 

 ine at various ages. A culture of a large rod should not be re- 

 corded as a non-spore-former unless all these tests are negative. 



Capsules. An organism should not be recorded as having cap- 

 sules unless they have been actually stained by one of the meth- 

 ods of capsule-staining described in bacteriological text books. 



Irregular forms. Forms that differ from the typical shape for 

 the organism (i.e., "involution forms," etc.) such as branching 

 forms, clubs, spindles or filaments should be noted and sketched. 



Special stains. Of these the Gram stain has been given par- 

 ticular attention by the committee and at present the Stirling 

 modification is recommended. Further work is being done at 

 present upon an improved method of making this stain, which 

 will be discussed in the next number of the Journal. The Stir- 

 ling modification is carried out as follows : 



Prepare gentian violet solution by grinding 5 grams in 10 cc. 

 of 95 per cent alcohol in a mortar. Add 2 cc. anilin oil, distilled 

 water 88 cc. Filter. 



Iodine solution is as usual : 1 gram iodine, 2 grams potassium 

 iodide, 300 cc. water. 



The procedure recommended in the 1918 report was as follows: 

 one minute in stain; wash in water; one minute in iodine solu- 

 tion; wash in water; two minutes in absolute alcohol; wash in 

 water; thirty seconds in counter stain (10 cc. saturated alcoholic 

 safranin in 90 cc. water). This procedure gives very good re- 

 sults; but recent work undertaken in the army cantonments 

 shows that equally good results can be obtained by the following 

 rapid method: one to five seconds in stain; wash in water; five 

 to ten seconds in iodine solution; wash in water; ten to twenty 

 seconds in absolute alcohol; wash in water; five to ten seconds in 

 counterstain. 



We are informed that the Stirling solution of gentian violet 

 can be made more stable by mixing normal hydrochloric acid 

 with the anilin oil before dissolving in water. (Add 0.5 cc. nor- 

 mal HC1 to 2 cc. anilin oil; dissolve in 88 cc. water and filter; 



