1900] MICROSCOPICAL JOURNAL. 15 



ilization, was the object of a paper by the writer publish- 

 ed in the first number of the Journal of Applied Micro- 

 scopy. 



The method then described materially lessened the time 

 and labor required in the preparation of agar and gave 

 a perfectly transparent product. Subsequent efforts, aid- 

 ed by a suggestion obtained from an article by Dr. Rav- 

 enel, in the June number of the Journal, have enabled 

 us to shorten the time limits from two and one-half hours 

 to one hour, counting from the time of the receipt of the 

 meat in the laboratory until the last drop of the com- 

 pleted medium has passed through the filter, and yet ob- 

 tained average results; while by deferring filtration un- 

 til after the first sterilization a perfectly transparent me- 

 dium is obtained. In tire latter event from half to three- 

 quarters of an hour suffices for the initial preparation, 

 exclusive of the time required for sterilizationin bulk,but 

 a half hour more is required on the following day for re- 

 heating and filtering. The process is as follows : 



Rub up 10 grams each of powdered agar and Witte's 

 powdered peptone, and 5 grams of sodium chloride, in a 

 porcelain-lined saucepan, with just sufficient water to 

 thoroughly moisten the powder and form a thin paste ; 

 add gradually, while stirring the mixture, 500 cc. of 

 water ; place on a gas stove, interposing a piece of asbes- 

 tos board or wire gause between the saucepan and flame, 

 and heat the mixture until the agar is dissolved, stirring 

 occasionally to prevent burningou the bottom of the dish. 

 If the paste made with cold water is properly rubbed up, 

 so as to break down all the lumps and moisten all the agnr, 

 solution will be practically complete by the time the boil- 

 ing point has been reached, so that two or three minutes 

 brisk boiling suffices. 



With the aid of a meat press extract the juce from 500 

 grams (one pound) of lean meat, and add the juice to 500 

 cc. of water. Mix this "fresh-water" with the agarsolu- 



