424 
Publications of Interest to Agriculturists. 
The pathological section of the work commences with an essay 
on the administration of medicines, followed by contributions on 
diseases of the digestive organs, poisons and poisoning, diseases of 
the heart and blood-vessels, and non-contagious diseases of the 
organs of respiration. The diseases of the nervous system, of the 
urinary organs, of the generative organs, the diseases following 
parturition, and the diseases of young calves come next in order. 
“ Bones, diseases and accidents ” form the subject of a separate 
chapter, succeeded by essays on surgical operations and tumours. 
Diseases of the skin, of the foot, of the eye, and of the ear are made 
the subjects of distinct contributions, and a chapter on infectious 
diseases of cattle completes the major portion of the volume. From 
this brief enumeration of its contents it will be seen that the work 
is comprehensive in its scope. It is, moreover, excellently printed, 
and many of the coloured plates are admirably executed. 
Some seventy pages and six plates are devoted to infectious 
diseases of cattle, and as expressing Transatlantic views on a subject 
of high international importance this may in some respects be 
regarded as the most interesting part of the volume. The interest, 
moreover, is not lessened by the circumstance that Dr. Salmon himself 
is one of the two joint contributors to this section. If apology 
were needed for the discussion of this subject, it is amply furnished 
in the following words : — 
The growing facilities for intercourse between one section of a country 
and another and between different countries cause a wide distribution of the 
infectious diseases once restricted to a definite locality. Not. only the 
animals themselves, but the cars, vessels, or other conveyances in which they 
are carried, may become agents for the dissemination of disease. The 
growing tendency of specialisation in agriculture, which leads to the main- 
tenance of large herds of cattle, sheep, and swine, makes infectious diseases 
both more common and more dangerous. Fresh animals are being con- 
tinually introduced which may be the carriers of disease from other herds, 
and when this is once introduced into a large herd the losses become very 
high, because it is difficult, if not impossible, to check a disease after it has 
once obtained a foothold. 
A definition is attempted of the kinds of disorders which may 
be grouped as infectious : — 
An infectious disease may be defined as any malady caused by the 
introduction into the body of minute organisms of a vegetable or animal 
nature which have the power of indefinite multiplication and of setting 
free certain peculiar poisons which are chiefly responsible for the morbid 
changes. 
This definition might include diseases due to certain animal parasites, 
such as Trichinae, for example, which multiply in the digestive tract, but 
whose progeny is limited to a single generation. By common consent the 
term “ infectious ” is restricted to those diseases caused by the invasion and 
multiplication of certain very minute unicellular organisms included under 
the general classes of Bacteria and Protozoa. Nearly all the diseases of 
cattle, for which a definite cause has been traced, are due to Bacteria. 
Among these are tuberculosis, anthrax, black quarter, and tetanus (or lock- 
