534 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
published in the Philadelphia papers after his decease, “ He possessed 
to the end of a long career the freshest capacity of seeing the opportuni- 
ties and openings for discovery and research offered by familiar phe- 
nomena. His vast store of exact and diverse knowledge in the whole 
wide field of animate nature was under the command of a logical judg- 
ment and synthetic powers which saved him from vagaries. These high 
intellectual powers were served by an untiring capacity for work and 
equal skill of eye and hand. These are rare gifts ; but they are none 
of them, nor all of them put together, as rare as his character. His 
simplicity, his transparent sincerity, his ingenuous anxiety to serve 
science and to serve science alone, his freedom from all desire for the 
rewards, the honours, and the recognition after which lesser men go 
a-wandering, were as remarkable as his scientific powers.” Never were 
words more truthful. Honours came to him from all parts of the 
civilized world, and more because unsought. 
/3. Technique.* 
Cl) Collecting- Objects, including Culture Processes. 
Preparing Tuberculin.f — Herr 0. Bujwid prepared tuberculin by 
cultivating the bacilli in glycerin-bouillon at a temperature of 38° C., 
after a period of three weeks the cultivation fluid was sterilized 
thrice, being kept for ten minutes each time at intervals of ten hours 
at 100° C. The fluid was then filtered and the filtrate inspissated in a 
water-bath to one-fourth its previous volume. At a pressure of 20 mm. 
the boiling-point was found to lie between 30°-34° C. A fine precipitate 
which then formed was filtered off and the fluid further inspissated to 
the consistence of syrup. Thus obtained, the tuberculin was thinner and 
lighter than Koch’s lymph. Experiments were then made on healthy 
and tuberculous guinea-pigs : the former bore well the injection of 
1 /2 ccm., while the latter manifested a general and local reaction. In 
two lupus patients who had been already treated with Koch’s lymph the 
characteristic reaction occurred after injection of 10 mg., but without 
any rise of temperature. 
The author considers that his tuberculin is about half as strong as 
Koch’s fluid, and does not believe it is a toxalbumin, but is rather 
inclined to hold that it is a ptomaine, or an intermediate between a 
ptomaine and an enzyme. 
Preparing Pepton-agar for studying Pyocyanin.J — M. Gessard 
gives the following ready method for making the pepton-agar so useful 
in studying the formation of pyocyanin. In each test-tube is placed 
0 • 25 grm. of finely-chopped agar, and then 5 ccm. of neutral 2 per cent, 
pepton solution and 5 drops of glycerin are added. The tubes are then 
* This subdivision contains (1) Collecting Objects, including Culture Pro- 
cesses; (2) Preparing Objects ; (3) Cutting, including Imbedding and Microtomes. 
(4) Staining and Injecting; (5) Mounting, including slides, preservative fluids, &c. ; 
(6) Miscellaneous. 
f Gazeta Lekarska (Polish), 1891, No. 4. See Centralbl. f. Bakteriol. u. Para- 
sitenk., ix. (1891) pp. 579-80. 
J Annales de l’lnstitut Pasteur, 1891, p. 65. See Centralbl. f. Bakteriol. u. 
Parasitenk., ix. (1891) pp. 541-2. 
