SOME FAULTS IN FORMALDEHYDE DISINFECTION OF 



POTATOES.* 



F. H. HALL. 



Formaldehyde gas and its solutions in water are con- 

 Why venient and effective disinfectants for use under 

 formaldehyde many conditions. As they require no fire in appli- 

 disinfection cation they are safer to use than sulphur, and they 

 is popular. do not corrode or tarnish metal fixtures or apparatus 



as do sulphur fumes; they are comparatively inodor- 

 ous, therefore more pleasant to apply and: quicker to disappear from 

 notice than carbolic acid and similar compounds; and they are not 

 poisonous, consequently far less dangerous to keep and use in homes 

 and on farms than corrosive sublimate. For these reasons, the 

 formaldehyde preparations have become very popular in human and 

 animal sanitation; and they are used with success, also, in preventing 

 some plant diseases, such as some of the grain smuts. 



In 1897, less than a decade after the discovery of the 

 Use in germicidal value of formaldehyde, its use, in liquid 



potato tuber form, was recommended for the prevention of potato 

 treatment. scab; and this method of treatment for insuring clean 



seed has become standard and is widely used. The 

 non-poisonous nature of the liquid recommends it to thousands 

 of growers in place of the dangerous mercury compound, corrosive 

 sublimate. 



Soon experimenters began using formaldehyde gas, generated by 

 heating the liquid, for treating potatoes, but in 1905 this was super- 

 seded by a new method. By combining the liquid formalin with 

 crystals of potassium permanganate, the formaldehyde gas is quickly 

 set free without the use of external heat. This new method gave 

 marked results in treatment for scab, apparently without injury 

 to the tubers. If equally safe and effective this gas treatment offers 



* Reprint of Popular Edition of Bulletins Nos. 3G9 and 370; see pp. 185 and 217 

 for Bulletins. 



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