[nicholls] blood sera IN TUBERCULOUS INFECTION S 



thing might hold good in tuberculosis. Without entering into details, 

 the chief conclusions to which they arrived were (1) that in animals the 

 subject of experimental tuberculosis the injection of dog's blood will 

 arrest the disease provided the germ be not too virulent, or will retard 

 it if it be very virulent. (2). The serum of a dog injected into a healthy 

 rabbit will prevent the development of experimental tuberculosis subse- 

 quently. (3) The serum of a dog previously inoculated with tubercu- 

 losis when injected into rabbits already tuberculized will aggravate the 

 disease. They did not believe that dog's serum possessed a specific 

 curative action in tuberculosis, although it seemed to have a powerful 

 action against some of the effects of the germ and exerted a tonic action 

 on nutrition (3.) Extract of dog's liver possessed similar properties. 

 In some of their later work they employed the ass (36). The blood of 

 the normal ass, like that of the dog, was found to retard the tuberculous 

 process, but the serum of an ass previously injected with tubercle bacilli 

 proved to be still more potent. 



The special merit of Héricourt and Eichet lies in the fact that they 

 were the first to see the possibility of producing by the injection of 

 tubercular virus a specific means of combatting the disease. It was 

 Maragliano (17), however, who first demonstrated by scientific proofs 

 that a tubercular antitoxin did exist and applied it to the treatment of 

 human tuberculosis. His results were given to the French Congress of 

 Medicine at Bordeaux in 1895, and his subsequent investigations have 

 proved to be so brilliant and painstaking that a brief reference here will 

 not be out of place. 



Koch's original tuberculin, at one time used largely for therapeutic 

 purposes, was prepared by heat, so that it did not represent the full 

 toxic properties of the bacillus, for, as Auclair has proved, certain vola- 

 tile poisons are given off in the course of preparation. These sub- 

 stances have been shown by Maragliano to cause convulsions when 

 injected into rabbits. The glycerine also used in the preparation is 

 toxic. Maragliano therefore employs a watery extract of bacilli. He 

 makes use of two toxins: A., prepared by concentrating a culture of 

 the bacilli over a water-bath at 100°C. for three or four days; and B., 

 a culture filtered through a Chamberland filter at the room temperature 

 and concentrated in a vacuum at a temperature less than 30 °C. For 

 inoculation purposes he uses three parts of A. and one of B. This mix- 

 ture is injected into horses beginning with a dose of two milligrammes 

 per kilo, of the body weight, increased gradually one milligramme a day 

 up to forty or fifty. The injections are stopped if the animals show 

 signs of fever or emaciation until recovery has taken place. The whole 

 process is spread over about six months. Before using the horse serum 

 thus prepared Maragliano waits' three or four weeks until the urine is 



