CHAPTER IV. 

 MEASLES. 



IN 1892, Canon and Pielicke, after the investigation of 

 fourteen cases of measles, reported the discovery of a 

 specific bacillus in the blood in that disease. 



The organism is quite variable in size, sometimes 

 being quite small and resembling a diplococcus, some- 

 times larger, and occasionally quite long, so that one 

 bacillus may be as long as the diameter of a red blood- 

 corpuscle. 



The discovery was made by means of a peculiar method 

 of staining, as follows : The blood is spread in a very 

 thin, even layer upon perfectly clean cover-glasses, and 

 fixed by five to ten minutes' immersion in absolute alco- 

 hol. These glasses are then placed in a stain consisting 

 of 



Concentrated aqueous solution of methylene blue, 40 ; 

 0.25 per ct. solution of eosin in 70 per ct. alcohol, 20 ; 

 Distilled water, 40, 



and stood in the incubator at 37 C. for from six to 

 twenty-four hours. The bacilli do not all stain uni- 

 formly. 



The discoverers of the bacillus claim to have made it 

 grow several times in bouillon, but failed to induce a 

 growth upon other media. 



The bacilli do not stain by Gram's method ; they seem 

 to have motility ; no spores were observed. They were 

 found not only in the blood, but also in the secretions 

 from the nose and eyes. They are said to persist through- 

 out the whole course of the disease, even occasionally 

 being found after the fever subsides. 



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