194 Report of the Department of Botany of the 



have observed that the formaldehyde gas is adsorbed to a great 

 extent by objects in the disinfection chamber. It has been pointed 

 out by Peerenboom, 15 Rubner and Peerenboom, 16 v. Brunn, 17 Jor- 

 gensen, 18 Walter and Schlossman, 19 and Werner 20 that the area of 

 the surface exposed by the walls and objects in the room may affect, 

 materially, the efficiency of the disinfection. However, it appears 

 that little or no account is taken of this in practical disinfection in 

 America. 21 In the formaldehyde gas treatment of seed potatoes 

 it has been entirely ignored. 



In order to determine whether the disappearance of the gas in the 

 experiments described above was due to adsorption the following 

 three experiments were made: A quantity of cobblestones (5.5 bu. 

 = 786.5 lbs. = 1485 stones) approximately the size and shape 

 of potatoes, and hence having approximately the same surface 

 area as potatoes, were washed and dried, then placed in the fumi- 

 gation box and treated with formaldehyde gas in the same manner 

 as a similar quantity of potatoes had been treated in Experiments 

 13 and 16. The stones occupied six crates. Thirty cubic centimeters 

 of formaldehyde solution and 14.25 grams of potassium perman- 

 ganate were used. The fumigation chamber was kept closed 24 

 hours. The test objects were 20 potatoes just commencing to 

 sprout. In the first stone experiment (No. 38) the initial humidity 

 was 75 per ct. and the maximum 81 per ct.; the initial temperature 



15 Peerenboom. Zur Verhalten des Formaldehyds im geschlossenen Raum und 

 zu seiner Desinfektionswirkung. Hyg. Rundschau 8:776. 1898. 



18 Rubner u. Peerenboom. Beitrage zur Theorie und Praxis der Formaldelhyd- 

 desinfektion. Hyg. Rundschau 9:266. 1899. 



17 v. Brunn, M. Formaldehyde desinfection durch Verdampfung verdiinnten For- 

 malins. Ztschr. Hyg. u. I nfectionskr. 30:216,230. 1899. 



18 Jorgensen, A. Untersuchung iiber Formaldehyddesinfection nach der Breslauer 

 Methode, speciell Desinfection von Uniformen betreffend. Ztschr. Hyg. u. 

 I nfectionskr. 45:279. 1903. With bibliography of 72 numbers. 



"Walter u. Schlossman. Munchen. Med. Wchnschr. 1899. Cited by Jorgensen. 



20 Werner, G. Zur Kritik der Formaldehyddesinfektion. Arch. Hyg. 50:361. 

 1904. 



21 Health officers in this country now quite generally employ formaldehyde gas, 

 generated by the permanganate method, for the disinfection of rooms in which 

 cases of contagious disease have occurred. The directions given usually call 

 for a certain amount of formaldehyde solution and potassium permanganate 

 per 1000 cubic feet of space without regard to the contents of the room. 



Although McClintic's investigation (Pub. Health and Mar. Hosp. Ser. U: S. 

 Hyg. Lab. Bui. 27. 1906) was made " with special reference to car sanita- 

 tion " no account was taken of the area of surface exposed. Probably, the 

 disappearance of the gas which McClintic observed in his car experiments and 

 which he ascribed to leakage (p. 78) was in large part due to adsorption. 



