To the Editor:—In answer to the letter of Dr. A. Clement Silverman, I shall refer first to the article published in the Journal of the American Medical Association (91:1786 [Dec. 8] 1928). On page 1791 appears the following:
"Ferry's and Degkwitz's serums were tried out in children over 4 in a measles outbreak in children's institutions, and a few private patients were also treated when convalescent serum would ordinarily not be used.
"In the first tests with Ferry's serum, one child came down with the first symptoms of the disease the day the serum was given and another child showed the symptoms four days later. None of the other treated patients or the controls became sick. The child who came down with measles four days after the serum had been given did not appear to have the disease modified. Two children, given the serum three and five days,