Springfield, Aug. 13, 1906.
To the Editor:
—In The Journal, July 28, page 288, under the above caption, Dr. Henry Albert refers to an article appearing in The Journal, July 14, page 139, concerning experiments made by the Illinois Board of Health. Dr. Albert says of the potassium permanganate method of liberating gas: "It is impossible to evaporate a pint of the 40 per cent, solution of formaldehyd with 3½ oz. of potassium permanganate. To do this it will require from 6 to 6% oz., and with the use of any less the disinfection, I am sure, will not be satisfactory."I have not found this to be the case. In many experiments conducted by the Illinois State Board of Health during the past year with this method of disinfection it has been found that while 3½ oz. of the permanganate would not fully evaporate 16 oz. of the 40