ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
493 
and not under the influence of a bactericidal product secreted by the 
leucocytes into the serum under the stimulus of the microbes. The 
bactericidal power of blood may be restored to it by adding living pus- 
corpuscles. With the aid of the Microscope all the phases of phago- 
cytosis may be watched. A very small part of the bactericidal power 
of the dog’s blood is ascribed to the serum. The filtered blood and the 
serum of man are almost as bactericidal to the common bacillus of the 
intestine as non-filtered blood ; and the same is true of the blood of 
pigeons and fowls. 
As a general result the authors conclude that immunity is not to be 
explained either by the phagocytic theory or by the theory of humours 
taken singly. Phagocytes and humours work together, in a varying 
degree in varying species, and with differences according to the nature 
of the aggressor, in order to preserve higher organisms against the 
invasion of microbes. 
Bactericidal Properties of Potash-Albumen.* — The experiments of 
Buchner, Emmerich, and others have shown that when blood-serum is 
heated to 57° it loses its bactericidal properties, and that these are 
restored if a little caustic potash be added. Dr. H. Scholl has made 
some experiments with the view of ascertaining if bactericidal properties 
could be imparted to other proteid bodies by the mere addition of 
caustic potash. For this purpose white of egg obtained with due anti- 
septic precautions was mixed with 0 * 3 per cent, caustic potash and the 
mass dialysed for 24 hours in 0*75 per cent, cooking-salt solution. 
This dialysed potash-albumen was then inoculated with typhoid bacilli 
and plate cultivations made directly after, three hours after, and six hours 
after inoculation. In the first plate 90,000 colonies grew up ; in the 
second 500, and in the third only 5. The albumen and globulin of the 
egg were then separately examined according to the foregoing method, 
and analogous results were obtained from both. The bactericidal pro- 
perties were not destroyed by heating up to 100°. 
Anaerobic Micro-organisms.f— After discussing the technique for 
the cultivation of anaerobic organisms, Sig. Sanfelice describes the 
growth and pathogenic properties of tetanus, symptomatic anthrax, 
malignant oedema, and nine other anaerobic bacteria found in earth, rotten 
meat, and faeces. The last nine are not pathogenic, and their growth is 
not distinguishable on agar, but only on gelatin, which is liquefied 
with the production of an ill-smelling gas. How frequently the bacilli 
of malignant oedema and of tetanus occur in the earth, the author shows 
by a number of experiments, for out of forty-eight guinea-pigs inoculated 
with surface earth, three died of tetanus and nineteen of malignant oedema. 
In another series twenty-two guinea-pigs were inoculated with earth 
taken from different depths, and of these twelve succumbed to malignant 
oedema and two to tetanus. 
In twelve other instances the animals died from other diseases. 
Some of these samples of earth were kept in the dark at 20° for several 
* Archiv f. Hygiene, xiii. See Centralbl. f. Bakteriol. u. Parasitenk., xv. (1891) 
p. 511. 
t Zeitschr. f. Hyg. u. Infektionskrankh., xiv. See Centralbl. f. Bakteriol. u. 
Parasitenk., xv. (1894) pp. 488-9. 
