ond day of infection have all recovered. While the experiments on animals showed that injections of the serum did not exercise a permanent influence in immunizing the animal, there can be no doubt that such injections would exercise a prophylactic effect if administered to those that have been exposed to diphtheria.
One of the great obstacles to the general employment of the serum is the cost of its manufacture. In this country from five to ten dollars is asked for a small quantity that sells on the continent of Europe for not more than one fourth of those sums. The British Institute for Preventive Medicine finds that the serum for a single case costs, to be manufactured, from fifteen to twenty-five cents. Public subscriptions have been started in various large cities in the world for the purpose of securing funds to establish and maintain laboratories for the manufacture of the serum. Roux estimated that for a population such as Paris has (two millions and a half) a serum laboratory would require twenty horses, three grooms, two bacteriologists, and two laboratory assistants, bringing the expenses of maintenance to eight thousand dollars a year, a sum that would be insufficient in this country, where the salaries, etc., would have to be so much higher.
Prom what has been said it may be deduced that the production of antitoxine serum is a matter of time, that it must be made with the greatest care, and that each lot must be tested to determine the degree of its antitoxic power. Only by such tests can its efficiency be determined, for there is nothing in the gross appearance of the yellowish fluid to indicate whether it will or will not exercise therapeutic influence. As no other remedy should be employed in conjunction with it, the dire results to the patient of administering a worthless serum may be appreciated. The Board of Health of New York has found specimens of serum, alleged to be antitoxic, exposed for sale, bacteriological tests of which demonstrated its worthlessness. This can only be prevented by the enactment of State laws that punish by heavy fine the sale of, or allow the recovery of heavy penalties for the administration of, any antitoxic serum that is not approved by the State Board of Health. The importance of exercising such control is appreciated abroad, where, in France, a bill is in preparation for introduction in the Chambers providing that no antidiphtheritic serum but that prepared under Roux's observation, or tested in his laboratory and found equal in curative influence to that prepared by him, shall be sold or administered. In Italy no antidiphtheritic serum but that prepared by Roux, Behring, or Aronson is admitted into the country. A good antidiphtheritic serum is not only harmless but is a remedial agent; a poor or spurious serum may be poise nous in itself as well as being worthless for controlling the disease.