CHAPTER XIV.

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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