1881.] NATURAL SCIENCES OF PHILADELPHIA. 437 



the coiu'se of a few days death occurred. The local symptoms 

 increased and widened. In some cases the false membrane 

 spread from where the poison had been put in the trachea up to 

 the mouth. The blood examined during life or after death was 

 found to contain micrococci precisely similar to those found in 

 the Ludinoton cases, and in a few instances micrococci were 

 found in abundance in the internal organs. Studies made upon 

 the blood of these animals, as well as upon the Ludington cases, 

 show that the micrococci first attack the white blood-corpuscles, 

 in Avhich they move with a vibratile motion. Under their influ- 

 ence the corpuscles alter their appearances, losing their granula- 

 tions. The}- finall}'^ become full of the micrococci, which now are 

 quiescent and increase until the corpuscle bursts and the contents 

 escape as an irregular, transparent mass full of micrococci, and 

 form the so-called zoogloae masses. In the diphtheiitic membrane 

 the micrococci exists frequently in balls, and it is plain that these 

 collections are merely leucocytes full of the plant. The bone- 

 marrow of the animal was found full of leucocytes and cells con- 

 taining micrococci. 



The question now arose, is the disease produced by diphtheritic 

 inoculation in the rabbit diphtheria ? They concluded that it is, 

 because the poison producing it is the same, the symptoms mani- 

 fested during life are the same, and the post-mortem lesions are 

 identical. The contagious character of the disease is retained, as 

 they succeeded in passing it from rabbit to rabbit. 



Their next series of experiments were directed to determine 

 whether the micrococci are or are not the cause of the att'ection. 

 The experiments of Curtis and Satterthwaite, of New York, have 

 shown that the infectious character of diphtheria depends upon 

 its solid particles ; for when an infusion of the membrane was 

 filtered, it became less and less toxic in proportion as the filtra- 

 tion was more and more perfect ; and when the infusion was 

 filtered, through clay, the filtrate was harmless. 



The urine of patients suffering from malignant diphtheria is 

 full of micrococci, and may contain no other solid material. Fol- 

 lowing the experiments of Letzerich, the}^ filtered this urine and 

 then dried the filter-paper. Upon experimenting they found this 

 even more deadU'^ in its ett'ects than is the membrane. The 

 symptoms and lesions following in the rabbit inoculation with 

 such paper are precisely those which would have ensued had a 

 piece of diphtheritic kidne}' or membrane been employed. This 

 experiment shows that the solid particles of the membrane, 

 which are the essential poison of malignant diphtheria, are the 

 micrococci, which must be either the poison itself or the carriers 

 or producers of the poison. 



Culture. — Experiments were performed in the manner com- 

 mended b}^ Klein and that recommended by Sternberg. The first 

 method seemed the best for the purpose of studying the develop- 



