2
17 is much to learn about the nutritive value of different food proteins, and it is encouraging to find that the proportion of the ingested nitrogen which becomes finally incorporated in the tissues of growing animals is increased from 23 to 27% as the degree of extraction of flour is raised from 70 to 100%. The nutritive value of protein hydrolysates and of milk substitutes for use as infant foods has also received attention, as have biological estimations of vitamins. These are a few of the useful findings published in some thirty papers during the year, and there is good reason for the feeling of the chairman of the governing body that the institute is well embarked on a career of new and expanding service to science and to the community. IMMUNISATION WITH THE VOLE BACILLUS THE vole bacillus, or the murine type of tubercle bacillus, occurs as a natural pathogen in some of the wild mice of Britain. It was first described by Wells 1 in 1937, when he wa,s collaborating with Elton in a study of the- diseases of voles in Great Britain. Tuberculosis in voles is a widespread disease, and is the only known instance of tuberculosis affecting wild animals in their natural habitat. The type of tubercle bacillus causing tuberculosis in voles is not pathogenic to the usual laboratory animals, the infection caused by the inocu- lation of the bacillus being transitory. This led Wells and Brooke 2 to investigate the question whether inocu- lation of guineapigs with the vole bacillus increased their resistance to subsequent infection with the human or bovine types of tubercle bacillus. Their experiments were interrupted at the outbreak of war and the animals had to be killed. At that stage of the experiment they concluded that vaccination of guineapigs with the vole bacillus gives a degree of protection against subsequent infection with virulent mammalian tubercle bacilli which is apparently far greater than has been recorded by other means. The immunisation experiments in guineapigs have been repeated by several workers (Griffith and Dalling 3, in this country, Irwin and O’Connell 4 in Canada, Wahlgren et al. in Sweden, Corper and Cohn 6 is America, and Birkhaug in Norway). The methods employed di ffer widely, but all agree that a pronounced increase of resis- tance to infection with virulent tubercle bacilli follows inoculation with the vole bacillus. It. is quite clear, however, that in the guineapig resistance does not amount to immunity. The effect of inoculation is a delay, often very considerable, in the establishment of : generalised disease after infection with virulent tubercle bacilli, but death from tuberculosis eventually follows. The painstaking work of Birkhaug makes this abundantly i clear. The average survival time of twelve unvaccinated 1 guineapigs after infection with virulent tubercle bacilli 4 was 192 days, whereas that of twelve animals vaccinated with the vole bacillus before infection was 403 days. i It is still uncertain how the resistance conferred on 1 guineapigs by vaccination with the vole bacillus compares with that produced by B.C.G. The results of Wells and 1 Brooke, of Irwin and O’Connell, and of Wahlgren and i colleagues, suggest that in the earlier stages of artificial 1 infection vaccination With the vole bacillus produces I the greater resistance. Corper and Cohn, and Birkhaug, I on the other hand, have found that the resistance con- 7 ferred is about equal, if the animals are allowed to f survive. It is very doubtful if immunity experiments i in tuberculosis in the guineapig can be translated into I terms of human immunity. The guineapig is absolutely i susceptible to infection with mammalian tubercle bacilli f and shows no natural resistance to progressive infection. t 1. Wells, A. Q. Lancet, 1937, i, 1221. 2. Wells, A. Q., Brooke, W. S. Brit. J. exp. Path. 1940, 21, 104. 3. Griffith, A. S., Dalling, T. J. Hyg., Camb. 1940, 40, 673. 4. Irwin, D., O’Connell, D. C. Canad. med. Ass. J. 1943, 48, 486. 5. Wahlgren, F., Olin, G., Widström, G. Nord. Med. 1944, 22, 943. 6. Corper, H. J., Cohn, M. L. Amer. J. clin. Path. 1943, 13, 18. 7. Birkhaug, K. Amer. Rev. Tuberc. 1946, 53, 411. In man, natural resistance, or resistance acquired as a result of previous infection, can completely overcome a tuberculous infection. In other words, infection in the guineapig is inevitably fatal ; whereas the result in man is determined by the balance between natural or acquired resistance and the infective process. An increase in resistance in man may lead to healing of the infection ; an increase in resistance in the guineapig merely delays its death. There are several questions still to be answered before the vole bacillus can be considered for human vaccination. Is it incapable of producing progressive disease in man ? Will it convert a negative reactor to tuberculin into a positive reactor, and how long does this sensitivity last ? Y Can human vaccination with the vole bacillus be done without causing severe local or general reaction ? Y Does human vaccination confer increased resistance to tubercu- losis It is hoped that the first three questions may soon be answered. The last question is vital, but the answer may be delayed for some time. Evidence of this nature is notoriously difficult to collect, and careful planning will be needed if the answer is not to be indefinitely postponed. BICENTENARY OF THE LONDON LOCK HOSPITAL AT the time the London Lock Hospital was founded 200 years ago, there were two ancient lock hospitals still functioning in London-all that remained of the seven lazar-houses granted to St. Bartholomew’s Hos- pital by Henry vm at the time of the dissolution of the monasteries. Locks, lazars, or outhouses were a recognised feature of the medieval hospital system of England. They were built by the pious especially for the treatment of lepers, because these outcasts were not admitted to the buildings attached to the monasteries reserved for the sick, the halt, and the blind. Instead, for them, wandering along the highways of medieval England with their begging-bowls and rattles, special lazar- houses were erected close to the monastery gates ; and there -at sundown the real lepers as well as the men covered with the foul ulcers of untreated scabies, the victims of lupus and rodent ulcer-all loosely diagnosed as lepers-were segregated. Outside the lazars, baskets of rags, lint, or wool were placed so that the lepers might wipe their sores before admission. The baskets were les loques (French for rags) and the lazars in Norman England came to be known as les locks. But when leprosy declined in Europe, and especially in England, towards the end of the 15th century, the lazar-houses became almost empty ; and it was then as it happened that syphilis burst upon an unprepared world. Naturally the lazars were hastily turned over to the treatment of venereal disease ; and the few remaining lepers were quickly swamped by the victims of syphilis. It is believed that it was in this way the word " lock became associated with venereal disease. Certainly there is no doubt that the hospitals for lepers became hospitals for venereal disease. Up to 1813, for instance, there was a plaque on a tumbledown building in Southwark labelled " The Chapel of the hospital for lepers, Le Lock, dedicated to St. Mary and St. Leonard. Founded prior to the 14th year of Edward n." This belonged to the old lock hospital for men in Kent Street, vacated by St. Bartholomew’s in 1760 after 2t centuries of use as a venereal hospital. It was returning from this hospital that Percivall Pott is said to have broken his leg, for the surgeons of St. Bartholomew’s were surgeons to Le Lock from the time of Thomas Vicarv until its extinction. It was possibly the knowledge that the lock hospital in Kent Street and the " spital" for women in Kingsland were about to be done away with, coupled with the great increase in venereal diseases in outer London, that induced William Bromfeild (1713-92), surgeon to St.
