218 DEPARTMENT OF THE NAVAL SERVICE 



8 GEORGE V, A. 1918 



Dunham Solution for Indol Production. — 1 per cent peptone, 5 per cent NaCl 

 dissolved in distilled water, the reaction adjusted to + 10, medium cleared 

 with white of egg, filtered, tubed and sterilized. After 7 days' incuhation at 

 37i°C. the cultures were tested for indol by the Bohme Ehrlieh test^ ; the 

 development of a cherry red colour indicating the presence of indol. 



Fermentation hrotlis. — The various sugars, alcohols, glucosides used were pre- 

 pared separately as 10 per cent solutions in distilled water, and sterilized for 

 15 minutes in flowing steam for three successive days. Immediately before 

 inoculation these were added to tubes of broth made up as for the indol test — 

 the use of peptone water without beef eliminates any risk of the reaction 

 being masked by action on the muscle sugar — in such proportions as to give 

 a final 1 per cent sugar or other carbohydrate broth. Dunham tubes were 

 used for the collection of the gas. For acid production the acid fuchsin 

 indicator of Andrade,^ as adapted by Hollman, was used at the rate of 

 2 per cent. 



In the preparation of the indicator I have noticed as reported by Andrade, 

 and Hollman that the colour which results from the addition of the normal 

 caustic soda is preceptihly affected by being left open to the air. By adding 

 the caustic soda to freshly prepared acid fuchsin solution at intervals through- 

 out the day, leaving the reagent meanwhile exposed to the air, I have found 

 that 2i oc. n/NaOH will decolorize to the proper shade of amber 100 cc. 

 fuchsin solution. 



Litmus Milk. — The milk freshly separated and tubed was sterilized for three suc- 

 cessive days for 30 minutes in flowing steam. The litmus was made up 

 separately; a 7 per cent solution of "Merck's" litmus in distilled water, 

 heated in the steamer for 30 minutes and left over night in the incubator, 

 filtered, sterilized for three successive days in flowing steam and added to 

 the milk immediately before inoculation at the rate of 14 per cent. 



Note : It will be seen from page 224 that culture III of this paper exhibited an 

 unusual degree of sensitiveness to the litmus. For this reason I now consider 

 the proportion of the indicator added to be of some importance. 



CULTUEAL STUDIES. 

 Culture I. 



Morphology. — Microscopically — 24-hour-old agar culture at 37°C.-^short rods vary- 

 ing up to 1-6 jx long and 1 jx broad; some larger forms; stains unevenly with 

 Kuhne's methylene blue, and is Gram negative. No spores are formed and no 

 capsule shown. 



Motility. — Decided brownian movement, but not the violent agitation noted in culture 

 III. No motility. 



Cultural Characteristics: — 



Agar Slope.— 2^ hours at 37°C. growth luxuriant, raised, slightly spreading, 

 moist, glistening, porcelain-white, edges echinulate. 



Glucose Agar Slope. — Gas, growth luxuriant, raised, moist, glistening, woolly 



appearance, haze, porcelain-white, spreading. 

 Tochtermann's Serum Agar Slope. — Resembling growth on glucose agar, but no 



woolly appearance. In 8 days growth had permeated medium as flakes ; gas, 



heavy precipitate collected at base of slope. 

 Loeffler's Blood Serum. — Moderate, spreading, flat, no digestion, no discolouration. 



In 7 days no digestion; colour isabella, luxuriant, moist, slightly raised, 



iridiscent. 



