The occurrence of a general cutaneous eruption consequent upon vaccination, that is to say the inoculation of vaccine virus upon an abraded skin surface, is a possibility generally recognised. But the meagre literature of the subject, and the scanty and brief references in present-day text-books of medicine indicate that the condition is only occasionally encountered.

(1) Dysentery strains from various sources have been examined with respect to their power of reducing nitrates to nitrites and of further destroying nitrites. All the strains with one exception (B. Neisser Ac.) reduced nitrates to nitrites. None of the strains which fail to ferment mannite (Shiga type) destroyed nitrites. Those dysentery strains which form acid from mannite differ amongst themselves in regard to their action on sugars and also in their effect on nitrites. Of the eight mannite-fermenting strains examined, two (B. dysenteriae Jürgens and B. Neisser Nc.) failed to destroy nitrites.

(2) B. dysenteriae Jürgens, although closely related to B. dysenteriae Flexner, differs from it both in its action on litmus-whey and in failing to destroy nitrite. It must therefore be considered a different strain. B. dysenteriae Jürgens is remarkable as being the only one of the strains examined which forms indol and at the same time fails to destory nitrites. It is consequently the only one which gives the cholera-red reaction.

(3) The addition of glucose (i.e. of a carbohydrate from which acid can be formed) enables Shiga strains to destroy nitrite.

(4) In the presence of an abundant supply of oxygen all the strains fail to destroy nitrites and nitrates.

(5) In glucose-containing media the inhibitory effect of oxygen is less marked.

(6) Under anaerobic conditions Shiga strains and B. dysenteriae Jiirgens still fail to destroy nitrites.

Typhus Fever is a disease which modern sanitary reform has banished from the midst of progressive communities. As a result few opportunities are now afforded for investigating the disease by the bacteriological methods of to-day. Sporadic cases and small epidemics occur from time to time in the few insanitary districts that remain in Belfast. Dr Ernest H. Milligan and I made some observations of a bacteriological nature on this disease which we communicated to the Ulster Medical Society in 1908. Since that time I have continued the investigations when any opportunity occurred and in this paper are recorded the results which have been obtained. Recently some new light has been thrown on the etiology of typhus fever, so the present time appeared to me to be opportune to publish our own observations, to analyse the findings of other observers and to discover what is truly established with regard to this subject.

The ultimate problem underlying many applications of the precipitin test, whether it be the determination of biological relationships, the identification of blood stains and other animal traces, or the detection of adulteration in food, is the recognition of the homologous protein (antigen) and its separation from closely allied heterologous proteins. Recognising that the antiserum is the main source of the precipitate in a precipitin reaction and having regard to the exact quantitative relations of antiserum, antigen and precipitate we have been able to arrange methods for the differentiation of proteins of closely related species and, we believe, to render more accurate the diagnosis of the source of individual proteins. To take a crucial instance, by means of an antiserum prepared with hen egg-white we have been able clearly to distinguish solutions of hen egg-white from all other avian egg-whites tested, including those of the duck, quail, partridge, pheasant and ostrich. So far as we know, Nuttall and Graham Smith alone have previously been successful in differentiating homologous and heterologous avian egg-albumens, and their methods appear to be more cumbersome than ours. Incidentally we have found that our results are not only consistent inter se but consistent also with the interpretation of the precipitin reaction which our previous observations had led us to adopt.

The term “Isolysin” was first employed by Ehrlich and Morgenroth in the third of their now classical series of papers entitled “Studies on Haemolysis(1).” It had been shown by Bordet that if the red blood corpuscles of an animal A are injected into another animal B, of a different species, the serum of B develops a haemolysin for the corpuscles of A. This haemolysin being produced in a different species of animal from that yielding the corpuscles, is termed, according to Ehrlich's nomenclature, a heterolysin.

We have recently had the opportunity of studying a plague epidemic that broke out on Terceira Island, Azores, in 1908. Terceira Island contains a population of 45,000 souls, the epidemic spread over 27 parishes. About 260 persons were attacked, with a mortality of about 48%.

According to Kossel (1888) Fritz Miiller discovered that phthisical sputum digests fibrin and coagulated albumen in weakly alkaline media, but the fact that antiseptic pus digests proteins seems to have been first observed by Leber.

Achalme (1899) separated proteolytic ferments from pus from various sources and Erben (1903) and Schumm (1904) drew attention to the notable quantity of albumoses in blood from cases of myologenous leukaemia which had been incubated, and the relative absence of this proteolysis in the incubated blood from cases of lymphatic leukaemia. Ascoli and Mareschi (1901) showed that the peritoneal exudate produced by aleuronat underwent autolysis under aseptic conditions.

A stock of 500 guinea-pigs at the Lister Institute was attacked by an epizootic and only 21 survived. These survivors showed definite immunity to a bacillus of the food-poisoning group (indistinguishable from B. aertryck and the B. suipestifer) recovered frequently from animals dying during the epizootic. Five of them have been proved to be carriers excreting the bacillus intermittently five month's later and the serum of all of them agglutinates the bacillus. Spread of infection apparently did not occur amongst contacts placed with these carriers in the few experiments carried out.

Krönig and Paul (1897) were the first to study the process of disinfection by making quantitative observations at intervals during its progress. Their figures showed that disinfection proceeded in an orderly manner and that the rate diminished as the number of survivors became less. Ikéda (1897) attempted to express their results by an empirical formula.

1. An epizootic killing 90% of a stock of 500 guinea-pigs has been described; cultures from these guinea-pigs frequently gave an organism indistinguishable by cultural or serological tests from the B. aertryck and the B. suipestifer.

2. This organism was highly pathogenic when inoculated subcutaneously into guinea-pigs and of low pathogenicity when given to them with food.

3. Healthy contacts put with animals infected subcutaneously or fed with the bacillus did not die.

4. Sterile filtrates of organs of guinea-pigs of the infected stock administered by different methods frequently killed.

5. The evidence definitely suggests that the essential infecting agent in the epizootic was a filter-passer.