PROCEEDINGS OF SECTION 1. 705 



natural resisting power of the patient by rational and hygienic measures, 

 as sunlight, fresh air, a liberal diet and regulated exercise, can never 

 be superseded by any other. But it is possible that in the future 

 some form of treatment will be discovered which, if used in conjunction 

 with the sanatorium treatment, will make the latter more successful 

 than it has been in the past. 



OPSONIC TREATMENT. 



Something is already being done in this direction. By a series of 

 ingenious experiments Wright has shown that a substance exists in 

 the blood which acts upon the tubercle bacillus (or other germs) and 

 renders it vulnerable to the white blood corpuscle. If one mixes 

 together equal volumes of white blood corpuscles, an emulsion of 

 tubercle bacilli, and normal saline solution, and incubates the mixture 

 at body temperature for 15 minutes, the leucocytes will not attack 

 the tubercle bacilli. 



We can examine the mixture with the microscope after incubation, 

 and we shall find the bacilli and the leucocytes lying free in the field 

 and no bacilli in the bodies of the white corpuscles. I will throw 

 upon the screen an exact representation of an actual experiment that 

 was made for me by Dr. Helen Mayo (Plate III., fig. 9). You will observe 

 that the tubercle germs are all outside the white blood corpuscle. 



The result would have been different if in the above experiment 

 we had used human blood serum instead of normal salt solution. In 

 other words, if one mixes equal volumes of white blood corpuscles, 

 an emulsion of tubercle germs, and blood serum, and incubates the 

 mixture for 15 minutes, then the white corpuscles will attack and 

 ingest the germs. I will throw upon the screen the result of this second 

 experiment (Plate III., fig. 10.) You will observe that many tubercle 

 germs are in the substance of the white blood corpuscles. It follows 

 from this experiment that the blood serum contains a substance which 

 has the power of acting upon the tubercle bacillus, and injuring them 

 so that they become attacked and eaten by the white blood corpuscle. 

 This substance Wright has called an opsonin. 



Opsonins, therefore, are substances which exist in the blood of 

 every individual, and protect him against the invasion of certain germs. 

 The blood of every healty person appears to contain nearly the same 

 quantity of opsonin, but if he contracts consumption then it is usually 

 found — at all events in the early stages of the disease— that the amount 

 of opsonin in the blood is diminished. 



Professor Wright's treatment aims at increasing the opsonin in 

 the blood. This is done by injecting under the skin at stated intervals 

 minute quantities of a sterilised preparation known as tuberculin. The 

 result of each injection is carefully determined by a somewhat elaborate 

 examination of the blood. The opsonic treatment is now being em- 

 ployed in several sanatoria. I have used it myself upon a number of 

 patients at the Kalyra Sanatorium, and in this work I have received 

 very considerable assistance from Dr. Helen Mavo. 

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