1 Mar., 1899.] QUEENSLAND AGRICULTURAL JOURNAL. 203 
examination for $d.: ‘ Ladies and gen’lmun, just clap your hies to this ere. 
vonderful and most stupendous hinsterment; it magnifies nearly one million of 
times or I’m a har, and any of you may be kenwicted of the ¢ruth of what I 
says by looking at the diamond-beedle with one hi, while you sees Hapsley’ Ouse 
with the hother. I'll be blowed if the beedle bint bigger nor that, and all of 
you knows Hapsley ’Ouse is a million times bigger nor the beedle.’? The 
audience seemed perfectly satisfied with the demonstration; for mankind are 
always much obliged to anybody who will be at the trouble of humbugging 
them in their own way, and fortunately there will never be a lack of persons to 
do them this kindly office, putting profit of course entirely out of the question.” 
From these remarks I do noi wish to infer that every stockowner I meet 
is ignorant of the nature and usés of the microscope ; far from it. I have met 
with some who, I am pleased to say, are able to give a number of extremely 
useful tips and dodges in general microscopy, and in fact are quite familar with 
some of the recent discoveries in practical bacteriology; on the other hand, 
there are hundreds who, if they had the aptitude, are unable to meet with the 
opportunity of acquiring even a rudimentary knowledge of the microscope or 
its revelations in connection with animal diseases. 
I intended when I commenced writing this address to briefly describe all 
animal diseases the study of which is known to be associated with the 
-microscope ; but I find that by dealing with the more important details of only 
four or five of the more common or every-day !diseases, I shall be doing all 
justice to my subject. Tirst of all I will take anthrax, as it was the first 
communicable disease discovered that was proved (by means of the microscope) 
to be caused by a specific organism, and it would be no exaggeration to say 
that the study of anthrax has been the groundwork for much of our 
xecent bacteriological knowledge. 
ANTHRAX. 
Anthrax, sometimes called splenic fever or Cumberland disease, is a 
disease which is largely seen in cattle and sheep, and sometimes in the pig, 
horse, dog, and other domesticated animals ; in fact, very few animals are proof 
against inoculation contagion. It is the most deadly disease to which the 
animal body is heir, and itruns its course with greater rapidity than does any 
other disease with which we are acquainted, death frequently resulting in cattle 
and sheep within the space of one or two hours after animals have been observed 
to be to all outward appearance in a perfect state of health. Its rapid course 
is only equalled by its malignity, few animals, especially cattle and sheep, 
recovering froin its destructive influence. In the year 1850 Davaine and Rayer 
made the very important discovery of the bacillus Anthracis, which is the 
immediate cause of anthrax; and although they describe its relative size to the 
zed corpuscles, and the fact that it is not possessed of any definite movement, 
as occurring in the blood of animals having died from splenic fever, they failed 
to recognise its real importance. In 1863, however, Davaine resumed his 
investigations, which he had discontinued thirteen years before, respecting the 
influence of the filamentous bodies which he had at that time noticed in the 
blood of animals which had died from splenic fever. ‘These researches were 
carried on for many years, till, in 1878, he asserted positively that these rods, 
which, he called “ Bacteridie du Charbon,” were the essential cause of this 
malignant disease ; they were constant in the blood of animals that died from 
anthrax, and that such blood when filtered and inoculated in animals had no 
effect. 
Since that time our acquaintance with these bacilli has been greatly 
extended by Robert Koch and others, and our knowledge of their life history 
confirmed by the most exhaustive and careful investigation. These researches, 
which ean only be carried out by the aid of the microscope, are still continuing, 
and we shall see later on what wonderfvl results in combating the symptoms 
their presence gives rise to; but we must briefly examine a little more in 
detail how the disease is communicrble from animal to animal. If the blood 
Pp 
