Royal Veterinary College. 
11 & 
substance termed mallein into veterinary practice as an aid in the 
diagnosis of that disease. During the past twelve months a large 
quantity of the agent has been prepared in the Research Laboratory, 
and supplied gratis to veterinary surgeons. Prejudice, and probably 
also ignorance regarding the nature of the substance, have prevented 
the general adoption of this means of detecting glanders in infected 
stables ; but the demand for it has been steadily increasing, and it 
has already been used with great success in the suppression of out- 
breaks, both in London and in the country. 
It is to be feared that in the case of some of the large horse- 
owning companies in London full advantage of mallein as a means 
of detecting cases of glanders has not been taken because, so long as 
compensation is not given for glandered horses destroyed, the com- 
panies shrink from ascertaining how many of their animals are really 
aftected. Some owners, although anxious enough to discover which 
of their animals have contracted the disease, refuse to allow mallein 
to be used with this object, owing to a fear that it might be a 
means of inoculating their horses with glanders, and at least one 
eminent veterinary surgeon has publicly expressed his apprehension 
that the substance might have this effect. It therefore appears 
desirable to explain briefly how mallein is manufactured, and what 
are its effects when introduced into the system by hypodermic in- 
jection. 
The first step in the manufacture of mallein is to obtain a pure 
culture of the germ of glanders. These germs are invariably present 
in the discharge from the diseased nose of a glandered horse, but it 
is generally a matter of difficulty to obtain pure crops of them from 
that source, because of the number of other species of germs acci- 
dentally present with them. At the post-mortem of a glandered 
horse, pure cultures may sometimes be obtained from unbroken 
glanders nodules in the nose, or from an unopened farcy bud ; or the 
germs may be separated from the accidental microbes by inoculating 
a guinea-pig with nasal discharge or farcy pus. The guinea-pig 
usually dies in the course of a few weeks, and in the diseased parts 
in its organs the bacillus of glanders is generally present as a pure 
crop. The medium most suitable for the cultivation of the glanders 
bacilli with a view to the preparation of mallein is faintly alkaline 
meat extract, or bouillon, to which 5 per cent, of glycerine has been 
added. Small flasks of this liquid are inoculated from a glanders 
abscess in a guinea-pig, or from a culture of ascertained purity on 
agar-agar or potato, and then placed in an incubator kept at a 
temperature of about 100° Fahr. In the course of a few days the 
previously clear liquid becomes turbid from the growth of bacilli in 
it, while a deposit of the germs begins to collect at the bottom of the 
flask. The incubation of the flasks is maintained for six weeks at 
least, and at the end of that time they contain innumerable glanders 
bacilli, as well as substances manufactured by these bacilli, and pro- 
ducts resulting from the death and disintegration of the numerous 
generations of them that have grown in the liquid during the six 
weeks. The smallest quantity of this liquid might suffice to give a 
