230 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
moistened with silver nitrate and lead acetate solutions. The former is 
stained by the phosphuretted hydrogen, the latter by the sulphur com- 
pound. 
Bacillus Pestis.* * * § — Dr. R. T. Hewlett was able to study the general 
characters of the plague bacillus from a case which occurred recently in 
London. Some of the original material was inoculated in a guinea-pig, 
the animal dying on the seventh day. The spleen and lymphatic 
glands were much enlarged, and in them were found enormous numbers 
of a short thick ovoid bacillus with rounded ends, and generally in pairs, 
the average size being 2 * 3 /x by 1 * 7 p. In young cultures the bacilli are 
extremely short, almost coccoid in fact ; in older cultures, rod, thread, 
and involution forms are frequent. In broth chains are formed. On 
gelatin and agar the growth is cream-coloured ; gelatin is not liquefied ; 
there is no growth on potato, and milk is not coagulated. There is pro- 
duction of indol, and with neutral litmus-sugar-agar a well-marked acid 
reaction after two days’ growth. 
Cultures retain their vitality for at least a month. Guinea-pigs die 
in from three to seven days ; if in three days, the enlargement and 
nodulation of the spleen may not be marked. Mice die in two to three 
days, and rats in about a week. 
The organism is met with in all parts of the body, the chief tissue 
changes being cloudy swelling, liyperaemia, and minute haemorrhages. 
Bacillus X Sternberg, and Bacillus icteroides Sanarelli.j — Recently 
Sternberg made an attempt to show that these two bacilli had certain 
points in common, and claimed that they were identical. This view is 
hotly disputed by Prof.M. Sanarelli, who is unable to find any ground for 
assuming that these microbes are identical. He states that he is well 
acquainted with Sternberg’s report, and has not met with a single bacil- 
lus amid the numerous microbic flora described in the report which has 
any resemblance to B. icteroides. 
Tubercle Bacilli in Butter.J — The prevalence of tubercle bacilli in 
market butter has, says Mr. H. L. Russell, been made the subject of 
special investigation by numerous workers. Groening § found that a 
large percentage of samples of butter produced in guinea-pigs patho- 
logical lesions similar to tuberculosis. Smear-preparations showed the 
presence of bacilli with staining reaction similar to that of the tubercle 
bacillus. 
Oberm filler || found tubercle bacilli in every sample (14) examined. 
Lydia Rabinowitsch % examined thirty samples in Berlin and fifty in 
Philadelphia. In 28 per cent, she found an organism which macro- 
scopically and microscopically closely resembled the genuine tubercle 
bacillus. Cultures, however, showed slight but distinct differences. 
The butter bacillus is mildly pathogenic to guinea-pigs, but not to other 
animals. Culturally and in its reaction to tuberculin it is readily dis- 
tinguishable from Bacillus tuberculosis . 
* Trans. Brit. Inst. Preventive Med., 1st series, 1897, pp. 136-41 (2 pis.). 
t Centralbl. Bakt. u. Par., l te Abb, xxii. (1897) pp. 668-74. 
j Bot. Gazette, xxiv. (1897) p. 442. 
§ Centralbl. f. Yet. Viehmarkt. u. Scklacht., 1897, Nos. 14, 15. 
1| Hyg. Rund., 1897, No. 14. f Zeitschr. f. Hvg., 1897. 
