The Science Committee OF THE British Medical Association

1912 BMJ (Clinical Research Edition)  
JUNE I5, 1912.] REPORTS TO SCIENCE COMMITTEE. IDIxALJOUA 1359 is necessary to shorten the period of auto-digestion as much as possible. The same reasoning, of course, applies if we are in search of an unknown virus, wlhich, however, pro-(luces a specific effect on a given organ, as does, for example, hydrophobia on the nervous system, vaccinia on the skin, and the lymplh beneath tile skin, etc. In dealing with the immnunity factor I was led by the consideration that we have to distinguislh
more » ... o distinguislh between tlle acquired immunnity of the individual and the inherited immuniity of the genus or species to whicih any given individiial belongs. -ThlerefoTe I used, in addition to the tissues and organs of adult individuals, those obtained from embryos and fetuses at different times of life, using especially cow antl pig embryos, becausc these are readily obtained from the slanghlterho'use. The younger an embryo or fetus the less will the acquired immiunity be; and the greater the differelnce in tllc species-for example, dog and rabbit-tlle more likely is it that we shall succeed in cultivating dog parasites in auito-digested dog extracts, and rabbit parasites in autodigested rabbit extracts. The above meentioned line of researchl has been applied by ffin to an investigation of thle virus of hydroplhobia and of vaccinia, anid a detailed accouint will be puiblished soon. My reason for lhaving suggested over two years ago to Professor Duval the use of thle banana vas this-that the skin and adjacent layers of the banana are fairly rich in oxidase, whichl latter in the presence of oxygen will act as an oxidizing 1medium, and in the absence of oxygen as a reducing agent. Othier media whichll ave been used by me are yellow lentils, from whiclh tlhe oxidases are readily extracted by 5 I-er cent. sodium chloride; and spleenis, fronm -whicll oxidases miiay also be obtained in large quatitities by ammoniamn or sodiumn chloride. My reasons for suggesting to Professor Duval, in connexion wvith hiis leprosy work, the three anmino-acids niamiiely, tryptophane, lysin, and cystin-are these: Heiriques slhoved' the absolute necessity of tryptoplhane for obtaining nitrogen equilibrium, and nmy own work slhowed the differenice between acid lhydrolysis and pancrcatic diaestion to be simply due to the fact tlhat the formiier destroys tryptophane, wlhile hydrolysis with alkalis. does not destroy tryptophane, and tlherefore acts as do trypsin and bacteria in general. Lysiti is als3 absolutely essential because it is absent in zein, gliadine, and muce(lin, which makes these foods unable to maintain nitrogen equilibrium, as is well known. Cystin was suggested for two reasons-first, because I thouglht it miglht be used for binding deleterious by-products from suichl aromatic compounds as tryptophiaie, phenols, etc.; and secondly, because at that time I was under the erroneous impression that the leprosy bacilhi attacked epithelial cells as well as tlhe snbjacent connective tissues, and, as is well known,
doi:10.1136/bmj.1.2685.1359 fatcat:siks7dijqne3zizbpjki3s3mfu