“To reassure ourselves of the value of this treatment and to eliminate all risks of error, we used the method of alternation. Without regard to the age of the patient, or the seriousness, duration or localisation of the diphtheria, or the dose of serum injected, we decided from 15 January 1905 to give calcium chloride to one in every two of our patients at the same time as the [serum] injection, the other patient receiving only the injection of serum.
Only the order of admission of the children determined their assignment to one or to the other category.
Of 516 children admitted between 15 January and 31 December 1905 to the diphtheria pavilion at the Trousseau Hospital who received injections of anti-diphtheria serum, 258 thus received calcium chlorate; 258 serving as controls did not receive this treatment.”
Translation by Ulrich Tröhler