The laboratory method here outlined and utilized by us over the past 11 years, of examining and judging ice-cream on a milk basis, appears to pro-vide a sieve of mesh generous enough to let through the passably ‘fit’ while stopping the presumably ‘doubtful’ and ‘unfit’.

Eighty-six samples of Alexandria milk ice-creams collected from various vendors in the city by Army Inspectors during the autumn months of 1944 showed, on this method, about 19% ‘unfit’—a result in remarkable agreement with fifty-eight samples from Municipal sampling, collected earlier in the year during summer months, which showed 16% ‘unfit’.

A small number of samples collected after hygienic control of the process of manufacture by Army Inspectors resulted in a total disappearance of unfit samples. The improvement arising from this controlled experiment was estimated at a lowering of 60% in total bacteria per c.c., and a reduction of 77% in coliforms.

The results of the latter experiment show what good results can be achieved in the betterment of milk ice-creams by simple hygienic measures, and should be more widely known in all centres where members of the Services are large consumers of ice-cream.

Acknowledgements are due to Lieut. J. T. S. Templeman, R.A.M.C., and his staff for their part in this investigation; and to Lieut.-Col. G. P. M. Marshall, R.A.M.C., A.D.H., for instigating the experiments on hygienic control of production.

1. The Tworts' potency measures correlate highly with all the reasonable alternative single measures of potency which have been examined.

1. Section A of this report is introductory; Section B deals with the correlations between the Tworts' measures of carcinogenic potency and certain alternative measures, and their use in testing the significance of differences between the potencies of different oils. Section C deals with the relation of potency to physical characteristics and place of origin of the oil. Section D deals with the relations between the saturation, refractivity, carcinogenic potency and place of origin of oils.

1. A clinical and biochemical study of a group of thirty patients from northern Portugal shows that they were suffering from a mild form of pellagra with no signs of severe malnutrition or of associated deficiencies except dental abrasion caries and pyorrhoea.

2. The diet of these patients in most respects was chemically satisfactory. Apart from a very low consumption of animal protein the gross intake of calories, total protein minerals and vitamins, including nicotinic acid, was satisfactory.

3. Since the syndrome was completely cured by nicotinic acid, it is suggested that the main characteristic of a diet on which pellagra is likely to develop is not a shortage of nicotinic acid, but a lack of high-grade protein.

4. A maize diet, satisfactory so far as calories and total protein are concerned, may produce pellagra because maize proteins are short of certain essential amino-acids. Other cereal diets may also produce pellagra if the general level of nutrition is very low.

5. The syndrome may be cured either by very large doses of nicotinic acid without change of diet or by moderate doses accompanied by abundant animal protein.

1. The problem of louse control by powders has been shown to be twofold, namely (a) to kill the lice present on a verminous person at the time of treatment, and (b) to prevent reinfestation of a deloused person or infestation of a clean person. In these experiments no single insecticide was found that would fulfil both functions.

2. The work shows the necessity of using laboratory tests (‘cell tests’) in conjunction with insecticide tests on the parasite living under natural conditions (‘field trials’).

3. The technique and results of the cell tests and the field trials are described in detail. In the field trials naturally louse-infested persons living in verminous surroundings were treated and examined daily to observe the true insecticidal value of each preparation.

4. Naphthalene was found to be the most effective insecticide for killing body lice quickly. It failed to give any protection against reinfestation.

5. The vegetable insecticides, derris and pyrethrum, were found to be toxic to Pediculns humanus corporis, but either alone or in combination with each other they were inferior to other combinations of insecticides.

6. The combination of high-boiling tar acids and derris resulted in the combined chemicals being more toxic to lice than either alone. This proved an activation effect, and the theory of activation is discussed.

7. Activated derris, while slow in killing lice, was shown to be the best preparation which gave protection against reinfestation.

8. The preparation referred to as A.L. 63 was outstanding as the best preparation that controlled body lice and which fulfilled the original conditions stipulated for a successful louse powder for human use. The formula is:

H.B.T.A. 2 %

Derris root 14·3 % giving 1 % rotenone and a minimum of 3 % extract in the final product

Naphthalene 50·0 %

China clay 33·7 %

The nature of each chemical in this formula is defined.

9. A.L. 63, when applied to the clothing of a verminous person, killed 95% of all lice on the treated garment in 24 hr., and gave complete protection against reinfestation for an average of 5 days, and partial protection for 8 days. When applied to clean garments as a prophylactic measure, A.L. 63 gave complete protection for an average of 7…8 days, and partial protection for approximately 16 days.

10. Patients living in a verminous environment were made to wear one shirt continuously for a month without washing it. Even under these conditions they were protected from infestation by treatment of the inside of the shirt, at 8-day intervals, with A.L. 63.

11. A short history is given of the use of A.L. 63 in the British army from 1940 to 1944.

During this work we have had much help and sympathy from many people, but we would like to place on record our especial thanks to the following: Prof. P. A. Buxton, of the London School of Hygiene and Tropical Medicine, for supplying us with the original material for establishing a louse colony, and for his great interest and encouragement during the work; Dr W. E. Parry, the Divisional Police Surgeon at Spitalfields, for his kindness in describing the best areas to search for suitable patients, and his assistance in finding suitable accommodation for establishing the ‘clinic’; those numerous volunteers, within the Cooper, McDougall and Robertson organization, who offered to feed lice when the colony was being maintained at the Research Station, and suffered much discomfort while doing so.