The plague suppressive campaign which is now drawing to a close in San Francisco has been conducted almost entirely on the principle that the great factor in the spread and continuance of the disease is the rat. The fact that the epidemic among human beings ceased within four months after the beginning of active operations and that in spite of the distribution of the disease in almost every quarter of the city, only one hundred and fifty-nine cases, with seventy-seven deaths occurred, proves the wisdom of this policy. The campaign has been conducted by the United States Public Health and Marine Hospital Service.

In determining the fermentative powers of this organism both fluid and solid cultures were used. The fluid medium was made up according to the formula employed by Dr M. H. Gordon. It consisted of Lemco ·1 gram, peptone ·1 gram, sodium bicarbonate ·1 gram, 10 per cent. watery solution of litmus 10 c.c., water to 100 c.c. This medium was sterilized by heating under pressure and to it was then added the substance to be investigated in the proportion of 1 per cent. Subsequent sterilisation was effected by heating in the steamer for 10 minutes on three successive days. In the case of laevulose, arabinose, and xylose the flasks were heated over the Bunsen flame, as in the steamer the medium turned red.

The practice of using preservatives in the process of making cider is very widely spread, and moreover is much encouraged by the makers of the preservatives.

In several former experiments by Bulloch and Craw (1906), Bulloch, Craw and Atkin (1908), and Craw (1908), we determined the relative efficiency of various filters in keeping back micro-organisms. The filters tested were the Doulton (“white” and “brown”), the Chamberland (“F” and “B”), the Berkefeld, and the Slack and Brownlow. Our methods of experimentation embraced filtration of cultures of microbes in bouillon, and the filtration of tap water under constant and variable pressures. The net result was that all the Slack and Brownlow, and nine out of ten of the Berkefeld filters employed gave contaminated filtrates within 15 minutes of the time the filtration experiment was commenced. Seven out of the ten Doulton “white” filters gave sterile filtrates for at least three days.

Svante Arrhenius (1908) has taken exception to my criticism (1907) of his interpretation of the Danysz Effect with reference to the Toxin-Antitoxin reaction. In this paper he has given an interesting but rather far-fetched analogy to the Danysz Effect, which is, according to him, purely chemical in character and subject to the laws of chemical mass action, and here marks in italics that “the opponents of the use of these laws have still given no explanation at all of the Danysz Effect, especially of the experiments cited in our memoir”.

Further India has been affected by plague to a small extent in comparison to the Indian Empire. Some considerable interest therefore attaches to the comparatively unimportant local outbreaks which occur, from time to time, in the Malay Peninsula. It is generally very difficult to explain the reason for their limitation and to determine, with any degree of accuracy, the source of the infection. Kelanthan, a small but populous and fairly healthy Native Malay State, situated in geographical position between 4° 45′ and 6° 25′ lat. N., and 101° 30′ and 102° 40′ long. E., has only been exploited by European enterprise during the last seven or eight years. The State seems hitherto to have escaped from plague. The Kelantan Malays in fact, so late as 1905, looked upon plague as a new disease and, for want of a better name, then referred to it as the “penyakit leher” or “neck sickness.” Numerous deaths from this so-called “neck sickness” were reported by the natives of the interior to have occurred at some remote villages in the month of May 1905. The illness appeared from the clinical descriptions given by the Malays at the time to have been bubonic plague. It was not thought necessary however by the Kelantan Government to take any special precautions to prevent its spread, and the disease disappeared of its own accord in a few months' time.

Many deaths occur every year in Egypt as the result of scorpion sting. These deaths are practically confined to Cairo and Upper Egypt, and are almost entirely among children. Unfortunately, owing to local conditions, it is almost impossible to obtain really accurate figures for this mortality, but some idea may be formed from the statistics given below of some of the larger towns.

In a previous paper (1906) I entered a plea for the use of certain tests in the bacteriological examination of waters and food stuffs as it seemed we should thus be enabled to better differentiate the lactose-fermenting bacilli. Such differentiation seems necessary because of the importance attached to B. coli as an indicator of faecal contamination, and because of the differences of opinion which exist as to the characters which justify us in identifying a bacillus as B. coli.

The following paper is based on the results obtained by cultivating and experimenting with strains of Meningococcus from 45 different cases of Meningitis. Twenty-five of these occurred in Epidemic areas and 20 were Sporadic cases occurring in London. The Epidemic strains are referred to throughout this paper as E. 1, E. 2, E. 3, etc., and the London strains (Sporadic) as L. 1, L. 2, L. 3, etc. For most of the Epidemic strains I am indebted to Dr M. Macdonald of the Lightburn Hospital, Shettlestone, and to Dr C. B. Ker of the Fever Hospital, Edinburgh. Also I have used strains sent to the Lister Institute by Professor Symmers from Belfast and by Dr Buchanan from Glasgow.

The incidence of Industrial Lead Poisoning is closely related to those sections of the manufactures which involve the production of dust. In white-lead works, paint-grinding shops, litharge grinding, electrical accumulator works, etc., the dust takes the form of minute particles of the special compound of lead manipulated by the workman. In smelting, desilverising, trimming metals and in file cutting, finely divided metallic lead, or a lead oxide, is present in the workshop air.