APRIL I, 1897 | 
NATURE 
317 
Melbourne, and Cape catalogues by the diurnal nutation and 
the annual displacement of the pole of inertia, the probability 
of the existence of diurnal nutation from observations, 
‘Chandler’s formulz for computing the variations of latitude, 
planetary aberration, and the new method of reckoning time 
(one to twenty-four hours) on the railways. All that one can 
desire to know about the weather in Belgium during the past 
year will be found in the excellent summary given by the 
meteorological director of the observatory, M. A. Lancaster. 
Several interesting plates are given in his summary. 
the end of the book various miscellaneous tables and yearly 
summaries will be found of general interest. 
THB JAMES FORREST LECTURE— 
BACTERIOLOGY. 
D* G. SIMS WOODHEAD, Director of the Laboratories 
of the Conjoint Board of the Royal Colleges of Physicians 
and Surgeons, delivered the James Forrest Lecture before the 
Institution of Civil Engineers on March 18. 
After a short introduction, the lecturer sketched briefly the 
history of bacteriology, and gave an account of Leeuwenhoek’s 
observations, some of which were either directly or through his 
friends communicated to the Royal Society of London. The 
organisms described by Leeuwenhoek, in 1683, ‘* were so small 
that they did not appear larger than represented at E (giving a 
copy of the figure), The motion of these little creatures, one 
among another, may be imagined like that of a great number of 
gnats or flies sporting in the air. From the appearance of these, 
to me, I judged that I saw some thousands of them in a portion 
of liquid no larger than a grain of sand, and this liquid consisted 
of eight parts water, and one part only of the before-mentioned 
substance taken from the teeth.” Leeuwenhoek’s microscopes 
magnified from 40 to 160 times. At that time he had not made 
up his mind as to the exact nature of these organisms ; he spoke 
of them as living animalculz, but in some of them he was unable 
to detect the slightest movement or any sign of life, nor did he 
theorise as to the meaning of the presence of these organisms in 
the situation in which he found them, though later, in 1713, he 
appeared to be under the impression that the organisms seen in 
the teeth were conveyed into the mouth by drinking-water that 
had been stored in barrels. 
The various forms of bacteria were then briefly described, 
their size, structure, and mode of growth. Alterations in form 
were noted, and the marked differences, not only in minute 
structure, but in mode of growth, and in the nature of their 
products were indicated. The modifications in the sheath or 
covering of these organisms were demonstrated, and the frog, 
spawn, or living glue masses were explained. Fine flagella 
were shown in organisms that differed very widely as to their | ni = 
| condition so that the oxygen present may have an opportunity 
nature and functions, and it was pointed out that, from what we 
know, however, of other flagella and cilia, and from recent ob- 
servations on the arrangement of the pores in the membrane, 
and the relation of the flagella to these pores, it is to be 
anticipated that they are usually, at any rate, processes directly 
continuous with the central protoplasm of the organism. At one 
time it was supposed that these flagella were formed only in | 
organisms that have a special affinity for oxygen ; but within the 
last couple of years it has been pointed out that the tetanus 
bacillus, the organism which grows best where free oxygen is 
excluded, often presents beautiful flagellated forms, although— 
and this is an important fact—the organism, as pointed out by 
Kanthack, remains non-motile when examined under the 
microscope in the presence of oxygen. Ilow it behaves when 
oxygen is excluded, has not yet been determined. Even those 
which have an affinity for oxygen appear to lose their flagella 
as soon as they leave the surface, and no longer require to move 
about in order to obtain this substance. 
Spore formation was fully described, and the great resistance that 
these “seed” spores present to heat and chemicals was noted. 
As an example of the importance of this spore formation, what 
takes place in the case of the splenic fever bacillus that is found in 
cattle was mentioned. When an ox dies of anthrax there are 
found in its blood an enormous number of short thick rods, the 
anthrax bacilli. If adrop of the blood be taken from a blood- 
vessel immediately after the death of the animal, the rods will 
be found, on microscopic examination, to contain no spores— 
that is, there are no bright points in the substance of the rod, 
and the animal, if buried at once before any blood or discharges 
NG. 1431, VOL. 55] 
Towards | 
from the body can get on to the land where the animal has died, 
will not be a source of infection ; the putrefactive organisms that 
develop being sufficient to kill off the anthrax bacilli that are in 
the blood. If, however, the animal be cut into, and blood be 
allowed to escape so that the organisms come into contact with 
the air, and the condition of the blood is altered in such a way 
that the nutritive supply of these organisms is gradually cut off, 
spores immediately begin to develop in the bacilli, and, as soon 
as this takes place, it is an exceedingly difficult matter to get 
rid of the disease ; mere burial is certainly not sufficient, as the 
Spores are not affected by the putrefactive organisms and pro- 
ducts—they retain their vitality, and only wait for more favour- 
able conditions under which to become again developed into 
the active and virulent anthrax organism. The knowledge of 
this fact, of course, hasa most important bearing on the treat- 
ment of carcases of animals that have succumbed to anthrax. 
Other forms of spores of a less resistent character have been 
described ; but it is scarcely necessary to do more than mention 
them, as they are not yet accurately understood. 
As to the effects of temperature upon micro-organisms, it has 
been found that most of the saprophytes (those that grow upon 
dead matter) flourish most luxuriantly at the ordinary tempera- 
ture of water, whilst the parasite or disease-producing bacteria 
grow and multiply most rapidly at the temperature of their 
animal or plant hosts. _ Most of these are killed at a temperature 
of 60° C. (140° F.). Certain bacteria, however, especially those 
found in soil and river mud, develop readily at 60° or 70° C., 
and flourish most luxuriantly at 50°C. C. Globig, and also, 
quite recently, A. Macfadyen, have shown that there are num- 
erous organisms which can exist at temperatures even higher 
than this, in spite of the fact that they contain no spores. Of 
the spore-bearing organisms Dr. Woodhead showed the tetanus 
and anthrax bacilli, both of which are pathogenic or disease- 
producing, and the bacillus subtilis or hay bacillus, which is 
found especially in hay infusions, and appears to be associated 
with the reduction of organic matter in the process of putre-' 
faction. 
The production of enzymes, of acids, and of gases was described 
to indicate what different functions these organisms may have ; 
and the different ways in which the aerobes and anaerobes are 
able to take the elements they require for their nutrition, and for 
the carrying on of their special functions, were explained, and the 
importance of these processes in the transformation and break- 
ing down of dead organic matter insisted upon. In nature the 
process of disintegration of such matter is divided essentially into 
three parts. It is necessary (1) to get all solid matter into 
solution ; (2) to supply as large a quantity of oxygen in as short 
a time as possible to this organic matter; (3) to attack the 
organic matter in solution by means of micro-organisms, and to 
so break it up that the various elements of which this complex 
material is composed may be thrown into an unstable or nascent 
of entering into combination, and of forming what are called 
oxidised substances. It is evident from what we know of putre- 
factive processes that these changes may take place in two 
perfectly different ways. In the one case we have the oxidation 
taking place directly, all the nascent substances being satisfied 
by the oxygen of the air, and the splitting up of the organic 
matter being carried on by aerobic organisms. In such a pro- 
cess of oxidation which takes place in porous soil well supplied 
with air and moisture, and also in water which is from time to 
time well saturated with oxygen, it will be found that little or 
no putrefactive odour is developed. The marsh gas, the sul- 
phuretted hydrogen, and other similar substances as they are set 
free, rapidly combine with oxygen to form sulphuric acid, 
carbonic acid and water; the nitrogenous substances in a 
similar fashion combining to form nitrous and nitric acids. In 
the soil these acids combine with the various basic substances, 
lime, magnesia and the like, so that they are rapidly removed 
and the way is left clear for the formation of fresh batches of the 
same substances. In anaerobic putrefaction, on the other hand, 
the process does not go on in this unobtrusive fashion, the an- 
aerobic organisms having, as it were, to wrest their oxygen from 
the organic molecules because there is no free oxygen present, 
set up a much greater disturbance, and the products of the 
decomposition, such as sulphuretted hydrogen, marsh gas and 
ammonia, are thrown off in an unoxidised condition, and in the 
free form (z.e. no longer in a nascent condition), they remain 
comparatively stable, and give rise to the odours so characteristic 
of rapid anaerobic putrefaction, 
