MICHIGAN ACADEMY OF SCIENCE. 147 



ordinary three-gallon pail and 480 Cc, one pint, of 40% formaldehyde was 

 poured upon them, these quantities being sufficient to disinfect 1600 cu. ft. 

 of space. 



As the spattering and foaming over the rim of pail caused by such very 

 violent ebullition were, to say the least, very objectionable, measures were 

 adopted to retard the reaction sufficiently to avoid this difficulty. After 

 trying several series of experiments, the desired result was successfully ac- 

 complished by incorporating with the potassium permanganate crystals 

 15% Portland cement and enough water to give the mixture the proper 

 consistency for compressing into small briquettes. After compression, 

 these briquettes are left until dry, when they can be readily handled. 



With the potassium permanganate crystals in this compact form, the 

 method becomes very simple and easy of operation. The charge, 480 Cc of 

 formaldehyde, is poured into a three-gallon metal pail, and the three 

 briquettes containing 240 grams of potassium permanganate crystals are 

 quickly dropped into th6 liquid. The reaction ensues more slowly and with' 

 less violence than when the crj^stals alone are used, and is not accompanied 

 by any undesirable foaming or spattering. 



In conclusion we believe the following summar}^ may be made: 



1. Formaldehyde disinfection is simply and ciuickly accomplished by 

 means of the permanganate briquettes. 



2. No expensive apparatus is necessary, and no outside heat is employed, 

 thus lessening the danger of fire. 



3. More thorough disinfection is accomplished, because the whole vol- 

 ume of gas and moisture is liberated during a very short time. 



Detroit, Mich. 



