Dr. Morton of the Department of Bacteriology, University of Pennsylvania School of Medicine, Dr. North of the Philadelphia General Hospital, and Mr. Engley of Camp Detrick under a grant from the Council of Pharmacy and Chemistry, American Medical Association have published an article in the Journal of the American Medical Association** evaluating the use of mercurials in medicine. This article, "The Bacteriostatic and Bactericidal Action of Some Mercurial Compounds on Hemolytic Streptococci: In Vivo and In Vitro Studies" reports that "Mercurial compounds have been employed as disinfectants since the beginning of bacteriology. Indeed, for a long period mercurial compounds, such as bichloride of mercury, headed the list of chemical which  were thought to be effective in the killing of microorganisms."

The authors reported, "...the label on a bottle of 'Solution Merthiolate [Thimerosal], 1 : 1,000, Stainless' purchased...states that it is 'a stable, stainless, organic mercury compound of high germicidal value, particularly in serum and other protein media.' " The authors stated in their article regarding this claim, "It [Thimerosal] is not highly germicidal and especially does not possess high germicidal value in the presence of serum and other protein mediums. The loss of antibacterial activity of mercurials in the presence of serum proves their incompatibility with serum."

In addition, the authors commented regarding the toxicity of Thimerosal, "The comparative in vitro studies of mercurochrome, metaphen and merthiolate [Thimerosal] on embryonic tissue cells and bacterial cells by Salle and Lazarus [Proceedings of the Society of Experimental Biology & Medicine, February 1935] cannot be ignored. These investigators found that metaphen, merthiolate [Thimerosal], and mercurochrome were 12, 35 and 262 times respectively more toxic for embryonic tissue cells than for Staphylococcus aureus. Nye [Journal of the American Medical Association, January 1937] and Welch [from the U.S. Food and Drug Administration, Journal of Immunology 1939] also found the same three mercurial compounds more toxic for leukocytes than for bacterial cells. Not only is there a direct toxic action of the mercurial compounds on the cellular and humoral components of the animal body, but there is also the possibility of sensitization."

It should be noted that Mr. Engley has subsequently published in the Annals of the New York Academy of Sciences## an article, "Evaluation of Mercurials as Antiseptics" in which he declared regarding mercurial compounds such as Thimerosal, "...mercurials are ineffective in vivo and may be more toxic for tissue cells than bacterial cells, as shown in mice (Nungester and Kempf, 1942) (Sarber, 1942) (Spaulding and Bondi, 1947) tissue culture (Salle and Catlin, 1947) and embryonic eggs (Witlin, 1942) (Green and Kirkeland, 1944), and with leucocytes (Welch and Hunter, 1940)." It is clear from this research supported by a grant from the American Medical Association that Thimerosal is neither efficacious nor safe, and should be removed as a preservative in prescription biologics and pharmaceutical products, as well as from topical over-the-counter products such as Butt-Balm that have Thimerosal present in their formulations as an active ingredient.

** It should be noted that this article was published in the January 1948 issue of the Journal of the American Medical Association ## It should be noted that this article was published in 1950 in the Annals of the New York Academy of Sciences