1. Statistical evidence and animal experiment have alike proved carbolised killed anti-rabies vaccine to be of undoubted efficacy in both pre-infectional and post-infectional treatment. Statistical evidence is furnished by the results of treatment of 90,000 patients, while experimental proof rests partly on the resistance shown by immunised animals to artificial infections with street virus, and partly on an estimation of degree and duration of rabicidal properties in their sera.

2. The Bordet-Gengou reaction is of no value as a qualitative or quantitative test for the estimation of anti-rabies immunity.

3. The efficacy of killed carbolised vaccine and probably of other antirabies vaccines is largely dependent on the concentration of the dosage and the period within which it is administered. Better results follow the giving of small doses over a number of days than the giving of larger doses over a shorter period.

4. It is impossible to reduce below a certain limit the time over which the total quantity of vaccine ordinarily sufficient for complete immunisation can be usefully administered.

5. The effect on rabbits of the subcutaneous injection of fresh-fixed virus is dependent on the quantity of virus introduced and on the duration of its period of administration. Few inoculations are more likely to cause death than several; repeated inoculations ordinarily confer immunity. Immunity thus acquired must have been produced within 11 or 12 days.

Under warm weather conditions, contamination from milking machine rubber parts can be effectively controlled by simple, practicable methods. Milk drawn by machines so treated is equal in sanitary quality to that produced by careful hand milking.

The chloramine-brine treatment proved to be quite as effective as the hot water treatment in controlling bacterial contamination, while superior from the standpoint of economy and simplicity.

It is impossible to say with certainty that the outbreak of illness in Manchester was due to ergot, but the evidence available strongly supports the view that ergot was the cause. The train of symptoms and pathological changes, though not necessarily peculiar to ergot poisoning, are strongly suggestive of this origin and this conclusion is reinforced by the fact that all the sufferers consumed rye bread made from rye which contained a significant proportion of ergot. The ergot isolated from this rye, after being kept for many months under conditions which were unfavourable for the preservation of its toxic properties, was found at the expiration of this period to contain some toxin and the amount found was consistent with the ergot having been highly active when fresh and therefore quite capable of causing the outbreak of illness which developed at a period shortly after the harvest when the toxic properties of ergot are greatest.

As a result of my inquiry the following facts of interest have emerged:

1. A considerable quantity of rye is grown in England and Wales and more than half of it is allowed to ripen. The districts in which most of it is grown are Yorkshire, Lancashire, Cheshire, Monmouth and Essex. Rye in this country is seldom, if ever, free from ergot and the degree of infection varies from year to year in each district according to the season, weather, seed and other conditions.

2. Rye bread is eaten to a large extent (in Liverpool and Manchester at any rate) by Jews, and rye for these towns is obtained almost exclusively from Lancashire and Yorkshire.

3. The rye grain is usually not treated in any way before milling, that is to say, no attempt is made to remove any ergot which may be present; it is ground into meal in the condition in which it comes from the threshing machine.

4. On the assumption that some of the rye consumed in Manchester contained 1 per cent. of ergot, a half-pound loaf of bread of which this rye is a constituent would contain 4 to 5 grains of ergot. Although this is a relatively small dose, it is possible that if consumed over lengthy periods, especially if the ergot were in an actively toxic state, pathological conditions might ensue.

5. The samples of rye actually examined by the Public Analyst were not found to be toxic. This may possibly be accounted for on the ground that the method employed for extracting the toxin was not satisfactory, or to the fact that the ergot examined was at least six months old, by which time it would normally have lost most if not all of its toxicity.

6. Damp weather favours the growth of ergot and the climatic conditions of the summer of 1927 were just those most suited to the development of ergot. It is probable therefore that the rye crop was heavily infected and the ergot rich in toxins.

The clinical characters of the outbreak, so far as they have been recorded, strongly support the view that ergot was responsible; all the necessary factors and conditions for the production of illness were present and it is not surprising that it occurred.

In view of the potential danger the obvious preventive measures to which I have already referred should be put into operation. Rye crops should be grown with such precautions as to reduce the risk of ergot infection to a minimum. Millers of rye for human consumption should install the necessary machinery to remove, so far as possible, any small proportion of ergot which the rye may contain.

No hygienist has any doubt that diseases of the intestinal tract, especially the enteric fevers, may be spread by the consumption of shellfish. Clinical experience, often repeated, led to this conclusion long before the bacteriologist had been able to detect the presence of the causative organism in the shellfish. In fact it is only within the past year that definite proof has been afforded by the exceedingly valuable work of Wilson (1928), who found B. typhosus in cockles taken from Belfast Lough.

(1) Of 71 cases of malignant growths the Shaw-Mackenzie test was positive in 49, doubtful in 5 and negative in 17. Epitheliomata of the skin all gave negative results, and some cases which had been treated with lead, X-rays or radium, and some cases of advanced inoperable carcinoma in old people also gave negatives.

(2) In 102 cases of various diseases other than growths (malignant or otherwise) negatives were obtained in 65 cases while 19 were doubtful and 18 were definitely positive. The chief conditions likely to give wrong "positives" are venereal disease, heart cases, nephritis, pulmonary tuberculosis, pregnancy and menstruation.

(3) Cloudy sera do not always clear on incubation with co-enzyme of pancreatic lipase, and unless such clearing takes place they should be discarded, as a high percentage of false positive results occurs in these instances.

(4) A 1 per cent, solution of cholin hydrochloride gave very similar results to the carcinoma extract.

I am deeply indebted to the following for supplying me with material, either serum or tumours, and without whose kind co-operation the work could not have been carried out: Dr Cooke, Addenbrooke's Hospital, Cambridge; Dr Varrier-Jones and Dr L. Stott, Papworth Hall, Cambridge; Dr L. King, Cancer Hospital, Fulham Road; Dr Piney, Charing Cross Hospital; Dr Perrin, Dr J. R. Marrack and Dr Sybil Robinson, London Hospital; Professor McIntosh, Middlesex Hospital; Professor F. R. Fraser and Professor G. E. Gask, St Bartholomew's Hospital; Dr Alport, St Mary's Hospital; Professor Maclean and Dr Osmond, St Thomas' Hospital; Professor Choyce, University College Hospital.

I also have to thank Professor Ellis, of the London Hospital, for kindly allowing me to work in the research laboratory on several occasions.

There are certain demonstrable changes that take place within the gastrointestinal tract during the process of adaptation to external stimuli. The body as a whole reacts in this adjustment to a changing environment. We have presented our evidence and indicated some instances where these gastrointestinal changes can be considered significant from an epidemiological and preventive medicine standpoint.

The loss of the self-disinfecting power, changes in acid-base equilibrium, and other demonstrable alterations within the lumen of the alimentary tract are only a part of the changes taking place in the organism during the process of adaptation to external environmental changes. If certain diseases are associated with a disturbance of the equilibrium between the parasites and the host, then it naturally follows that we must have more information upon the biological mechanism of the host in regard to its changes in susceptibility and resistance to the parasitic environment. Our present knowledge of bacteriology throws little light upon this epidemiological question. It has been the aim of the author to study the mechanism by which the organism adapts itself to certain environmental changes. We have avoided using pharmacological and other artificial agents that would produce body changes, but have restricted ourselves to simple alterations in diet, external temperature and similar mild or natural environmental factors, and followed the mechanism of adaptation to these physiological stimuli.

The loss of the power of a body-covering layer, to destroy bacteria in contact with it, must increase the hazards of invasion of this body surface by bacteria. We have shown that a sudden change in the intra-intestinal acid-base equilibrium leads to an inhibition of the mucosa to destroy bacteria within its lumen and is accompanied at times by the appearance of viable bacteria in the thoracic duct lymph stream.

If an organism does not adapt itself to its meteorological environment, it is more susceptible to its parasitic environment. The same is true of the nutritional environmental factors. Disturbances due to lack of adaptation to climatic changes can in part be offset by altering the diet. The weather and food factors cannot be separated and one can influence the other.

Changes in climate are beneficial to the well-being of the population living in the temperate zones where meteorological conditions are ever changing as compared to the steady cold in the arctic or constant heat as in the tropics. Changes in food are also beneficial. A high protein meal is stimulating. In the tropics where the skin is in a state of over-stimulation due to the high external temperature and humidity the ingestion of an alcoholic beverage to stimulate the splanchnic system before a meal is beneficial. Acidifying an infant's food in hot weather is a common practice. Many such instances could be cited. It seems to be of advantage to an organism to be in a changing environment. The tonus of our physiological systems is not static or fixed, but is ever changing. The more delicate the index used to measure functional changes, the more frequently are such changes observed. These alterations in environment must not exceed the power of the organism to adapt itself to these changes.