The interest of this case is due to the fact that the patient from whom this bacillus was isolated was a tabetic in whom a spontaneous fracture of his femur had occurred, and cellulitis developed at the level of the lesion due to a diphtheria-like bacillus. This organism was isolated and obtained in pure culture from the cellulitis and was found present in the films of the pus; also the patient's serum gave a complement fixation reaction with his own bacillus and for syphilis.

The practice of flour bleaching originated in this country about ten years ago; bleaching, however, is said to have been attempted in France two or three years prior to this. The practice was rapidly adopted by millers in the United Kingdom, in America, and elsewhere. Such bleaching is applied only to roller-milled flour. Numerous patents have been granted for bleaching appliances and for the application of various chemicals to the bleaching of flour. Ozone, chlorine, oxides of chlorine, bromine, nitrogen peroxide and other oxidising substances have been suggested and tried as bleaching agents. Of these substances nitrogen peroxide is the only one which has given satisfactory results, and all commercial bleaching of flour at the present time depends on the use of this substance. It can be produced in various ways and from a variety of materials. Two methods of production, which may convniently be termed the chemical and electrical methods, are in use commercially at the present time. In the first of these nitrogen peroxide is produced by the action of nitric acid on ferrous sulphate, the amount of gas formed being controlled by regulating the supply of acid and ferrous sulphate. A current of air charged with the gas is led through a revolving reel or “agitator” as it is called, through which a stream of flour is continually flowing. The flour in its passage is throughly exposed to the action of the nitrogen peroxide, and is bleached when it emerges from the agitator. In actual practice this process possesses certain commercial disadvantages. The apparatus requires constant attention if the degree of bleaching is to be properly controlled; overbleaching and condensation of acid resulting in local staining of the flour are liable to occur, while in the hands of ordinary workmen the use of strong acids is not entirely free from risk. As regards expense, it compares unfavourably with other methods, some of which are said to be worked at one-tenth of the cost of the acid process.

The action of air containing nitrogen peroxide upon flour, in quantities up to 300 c.c. of nitrogen peroxide to one kilogramme of flour, may be summarised as follows:—

I. The golden-yellow tint of the flour is destroyed. Immediately after bleaching no difference in tint due to excess of the bleaching agent could be observed with Lovibond's tintometer, but on keeping for several days the more highly bleached samples became decidedly yellow, while those treated with 30 to 100 c.c. of nitrogen peroxide per kilogramme became still whiter, the maximum of bleaching effect being attained within these limits.

II. The amount of nitrous acid or nitrites present in a freshly bleached flour is approximately proportional to the amount of nitrogen peroxide employed, and corresponds to about 30% of the total nitrogen absorbed, rising to 40% in the more highly bleached samples. After the lapse of several days, the proportion of nitrites present decreases considerably in the higher concentrations, but remains very nearly the same in the more slightly bleached samples.

III. Approximately 60% of the total nitrogen introduced as nitrogen peroxide into the flour during bleaching can be recovered as ammonia a short time after bleaching by reducing the aqueous extract of the flour with a copper-zinc couple, and may be assumed to be present in the flour as nitric and nitrous acids or as nitrates and nitrites. After keeping the bleached flour for some days the amount of nitric acid extracted with cold water decreases. Experiments with pure glutenin and gliadin indicated that in certain circumstances nitric acid may be withdrawn from solution or “adsorbed” by these proteins.

IV. In highly bleached flour a considerable increase in the amounts of soluble proteins and soluble carbohydrates takes place. If one kilogramme of flour is bleached with 300 c.c. of nitrogen peroxide, the amount of soluble nitrogen is doubled. This appears to be due almost entirely to the solubility of gliadin in nitric acid of certain concentrations. The simultaneous increase of soluble carbohydrates would seem to point to an intimate relationship between the gliadin and certain carbohydrates in flour.

V. If highly bleached flour is allowed to stand for some time after bleaching, the oil undergoes very considerable alteration and acquires the characteristics of an oxidised oil. About 6 to 7% of the nitrogen introduced as nitrogen peroxide during bleaching is absorbed by the oil.

VI. The absorption of nitrogen peroxide by flour does not appear to be accompanied by the production of free nitrogen, nor was any evidence obtained of the formation of diazo-compounds.

VII. Sodium nitrite was found to exert no inhibitory action on the digestion of soluble starch by saliva, but the rate of digestion was greatly retarded if the starch had been previously treated with nitrogen peroxide gas. Bleaching was found to exercise an inhibitory effect on the salivary digestion of flour.

The results obtained in these investigations were negative throughout, but perhaps are worth recording as tending to show that the formation of such ‘anti-bodies’ as cytolysins and precipitins is not a necessary reaction on the part of any living organism to the presence of foreign cells or substances.

Ever since artificial media have been used for the cultivation of micro-organisms, the question as to what is the best reaction—that is the degree of acidity or alkalinity—has been a moot point. It has been assumed gratuitously that there is an optimum reaction which is the same for all the common bacteria met with in the laboratory. In recent years however some attempts have been made to settle the question definitely, notably by Eyre and Deelemann. On enquiring what reaction of medium was adopted in six different London laboratories, Eyre found that very divergent standards were used, ranging from 20 units of acidity to 10 units of alkalinity on his scale. (20 units of acidity implies that 20 c.c. of normal alkali must be added to each litre to make it neutral to phenolphthalein. In the case of alkalinity the indicated number of c.c. of normal acid must be added.) The importance of having a definite reaction had until recently not impressed itself upon the majority of bacteriologists. The possibility that although many organisms may grow on media of comparatively widely differing reactions, yet only one of these reactions may be suitable for the growth of a more delicate kind, had been overlooked. Consequently they failed to grow bacteria which by careful adjusting of the reaction of the medium could be readily cultivated. Martin (1910), for example, has lately pointed out the ease with which gonococcus can be made to grow on serum agar if the reaction is carefully adjusted. In later years the subject has assumed still more importance in connection with the production of bacterial toxins, which have been submitted to a large amount of investigation. In the production of diphtheria toxin it was soon recognised that bouillon containing more alkali than is usually employed for ordinary bacteriological work, yielded the most toxin, and even various devices were invented to avoid the initial production of acid which usually takes place as the consequence of bacterial growth in a sugar-containing medium. Madsen (1896) has made a thorough examination of the factors governing the production of diphtheria toxin. By following the reaction of a growing culture from day to day he found two different types of growth occur,—one in which the medium increases in acidity without abatement, and such cultures are atoxic; in the other the primary increase in acidity is followed by a decrease, and subsequent increase in alkalinity. These cultures are sometimes toxic. The two conditions seemed to have relation to the amount of alkali added in the preparation of the bouillon, in that a strongly alkaline medium gave an alkaline end reaction while a less alkaline medium gave sometimes an acid and sometimes an alkaline end reaction.

Preliminary record of attempts to produce the typhoid-carrier state in the rabbit and to obtain evidence of the presence of this condition by bacteriological examination of the faeces.

(1) When rabbits are injected intraperitoneally with ox's red blood corpuscles the haemolytic immune-body which is developed shows qualitative differences at different stages of immunisation.

(2) The immune-body molecules which appear in the serum in the early stage of immunisation (e.g. four to eight days after a single injection of 2 to 4 c.c. of red blood corpuscles) are deficient in the power of causing absorption of complement when added to the corresponding blood corpuscles. This is most clearly brought out by the very slight increase in complement absorbed under the influence of multiple doses of immune-body as compared with the amount absorbed by one dose. The deficient complement absorption does not depend to any marked degree on deficient combination of immune-body with the receptors of the red corpuscles.

(3) When, after repeated injections of blood corpuscles, immunisation has been carried to such a stage that an immune-body is produced which is very active in causing absorption of complement, then it is found that on ceasing to give further injections the relative complement-combining power remains high after the immune-body content of the serum as measured by the haemolytic dose has fallen to a very considerable extent.

So far as we are aware the occurrence of such alterations in the properties of immune-body during the process of immunisation has not hitherto been noted.

1. Diphtheria toxin-antitoxin mixtures induce a higher immunity in guinea-pigs than sub-lethal doses of toxin; one injection of the mixture being sufficient to produce an immunity lasting in some cases for a period of over two years, as shown by the passive immunity conferred on the offspring.

2. The highest immunity is produced by toxin-antitoxin mixtures containing the most uncombined toxoid.

3. The active immunity of the mother is transferred passively to the offspring.

4. The passive immunity thus transferred usually disappears at the end of two months after birth, and only in rare instances has been recongnised after three months.

5. Immunity is mainly transmitted in utero, and only to a slight extent during lactation.

6. Young bred from does that have been used for a single routine antitoxin test may be able to tolerate 14 times the does of diphtheria toxin fatal for a normal guinea-pig.

Some deep wells in the chalk are liable to contamination. The pollution may gain access to the wells by means of fissures or “swallow-holes” in the water-bearing stratum, and, through these defects, micro-organisms and organic matter may find their way into the water supply of a town from points many miles distant. The risk of chalk waters becoming contaminated is daily growing more probable: quick and cheap transit is responsible for an exodus from the town to the country which serves as a gathering ground for water supplies; and the chalk uplands and countryside, which formerly were sparsely populated, are in many places becoming covered with collections of houses and small villages, whose only method of sewage disposal is by means of cesspools into the chalk on which the houses are built. If the chalk is sound and unfissured, this method of sewage disposal is not harmful to distant water supplies; but, given a fissure or swallow-hole, the intestinal micro-organisms and organic matter from some outlying village, may make the water from a deep well some miles away unfit to drink. I know at present of five important wells in the chalk in different parts of England, which are, in this manner, liable to intermittent and undoubted faecal contamination; but, in only two of these places are means taken to purify the water before it is distributed to the consumers. A typhoid carrier or a case of enteric fever might distribute bacilli to a distant town through some imperfection in the stratum, and the consequences, without doubt, would be very disastrous; yet probably there are many towns in the country which take the risk of such an epidemic.

In a case of suppurative cholecystitis with cholelithiasis a bacillus was isolated from the pus, gall bladder, and stools which has the morphological, biological and cultural characters of B. enteritidis Gaertner. This bacillus is pathogenic for the rat, rabbit and guinea-pig, and gives rise to the characteristic lesions produced by the Gaertner bacillus. The serum of the patient agglutinated the three strains of bacilli isolated from the above mentioned sources and the original Gaertner strain in a dilution of 1 in 40. A serum, prepared by injecting B. enteritidis Gaertner (original strain) into a rabbit, agglutinated the three strains isolated from the case and the homologous bacillus in almost the same dilutions.

A serum prepared from any of the three bacilli agglutinates the homologous organism, the other two strains and the original Gaertner bacillus in almost the same titre. The sera homologous to allied organisms do not agglutinate these bacilli. Absorption tests confirm these results and prove that the bacilli isolated are identical with the Gaertner bacillus.

The chief points of interest in the case are that:

1. It forms a link in the chain of evidence showing that as in the case of the paratyphoid bacillus the B. enteritidis Gaertner may give rise, not only to the more acute toxic from of poisoning, but also to a sub-acute paratyphoid type of the disease.

2. It establishes the association of B. enteritidis Gaertner with suppurative cholecystitis and with cholelithiasis.

3. It proves that this bacillus may have its habitat in the gall bladder and be shed out at intervals into the faeces, in a manner exactly analogous to what occurs in the case of typhoid and paratyphiod infections.

The preparation of a medium that would allow the bacillus of diphtheria to grow and exclude all other organisms would be an ideal medium for those whose work is concerned with that organism, but, as such a medium has not yet been devised, we must be content with the modifications of the ordinary media which we possess. Various varieties of media have been prepared for the purpose of favouring the growth of B. diphtheriae, but very little seems to have been done with regard to selective media.

Certain difficulties attendant upon bacteriological diagnosis recur constantly in connection with the notification, isolation, and discharge of patients suffering from diphtheria, and from every point of view it becomes increasingly necessary to seek means to minimise, as far as possible, the number of ‘missed’ and ‘carrier’ cases.

1. When fleas bit through films of Tuberculin, Vaccine Lymph, and Staphylococcus Emulsion lying upon the human skin, no inoculation was observed in 188 instances out of 195. In six of the experiments with Tuberculin, inoculation followed, which possibly was not due to the flea-bites. Controls gave positive results.

2. When the same materials were rubbed over recent flea-bites, no inoculations followed. Controls were positive.

3. A very minute dose of Tuberculin, such as might be conveyed by a flea's proboscis, will produce a recognisable reaction in a susceptible person.

4. The bearing of the results on the question of plague transmission is discussed.

This Congress was originally announced to take place in 1910 (see Journal of Hygiene, 1909, vol. IX. pp. 347—356) but the date was subsequently altered to 1912. Certain changes in the organization have been made, as appears from a notice which has recently reached us. This notice states that: