202 PHARMACEUTICAL BACTERIOLOGY 



change. The amount used will depend upon the quantity of powder to be 

 made. 



C. Preparing the New Kefir. — Wrap the washed and softened kefir in a 

 piece of sterilized gauze and place it in one quart of pasteurized milk. 

 Keep at a temperature of 82° F. Allow to stand for from twelve to fifteen 

 hours, until the milk is curdled. 



D. Skimming and Draining the Kefir. — -Remove the cream and drain 

 the curd (kefir) in steriUzed gauze until quite dry. 



E. Drying. — -Add (to the drained kefirized curd) an equal weight of 

 sugar of milk, mix, and spread thinly upon sterilized gauze or upon a sterile 

 glass plate and dry in a current of sterile warm air (80° F.). 



F. Powdering. — ^Powder the dried mass gently and put up in dry, sterile, 

 one-ounce, wide-mouthed vials, closed with sterilized corks. 



G. Directions for Use.— Upon the bottles place the following directions 

 for using the powder thus prepared: "Dilute one quart of milk with on^- 

 half pint of water, add a pinch of salt and one level teaspoonful of the 

 powder. Set aside for twelve to fifteen hours at a temperature of 85° F. 

 shaking frequently. Use at once or keep on ice." 



There are, of course, no conveniences for regulating the temperature in 

 the average household, and the action of the powder must take place at the 

 ordinary temperature of the home. Thus the time required to curdle the 

 milk will vary. The powder should be kept in a cool or cold, dry place. 

 Of course, a small amount of kefirized milk can be used to curdle any 

 quantity of fresh milk without using any of the powder. 



The pharmacist should test the kefir which he is about to use in pre- 

 paring the powder, in order to be certain that it is active in curdhng milk. 

 Likewise should he test the powder prepared from it. 



The kefir powder above described is similar to, although not identical 

 with, certain microbic lactic-acid ferments found on the market, as the 

 lactone tablets, bacillary tablets, yoghurt tablets, fermenlactyl, lacto- 

 bacilline and others. These are prepared from pure cultures of species of 

 lactic-acid bacilli, dried and formed into tablets with some pulverulent 

 (starch, milk, sugar) base, ready for use. The milk (in quart bottles) is 

 first pasteurized, a pinch of salt is added and two or three tablets are crushed 

 and mixed with the milk. In a day or so the milk is transformed into an 

 acidulous drink, resembling buttermilk somewhat in flavor, though it is 

 not buttermilk, as is generally supposed. 



These tablets have gained in favor within recent years. They deterio- 

 rate in time, as already stated, and the time-limit is stamped on each 

 container. Like the kefir, they act more quickly at a temperature of 

 about 25° C. 



As may be readily understood, kefir, lactone, etc., will not produce the 



