A protein having the properties of the tobacco mosaic virus has been isolated from the juice of plantes suffering from the disease. The protein has a molecular weight between 15 and 20 millions. It is liquid crystalline, and has certain properties which resemble those of genes. The isoelectric point is 3.3, as compared with 7.6 for rdinary viruses, as vaccinia. Similar proteins have been found in other plant virus diseases, and one of molecular weight of over 20 million has been found to be the active agent in infective rabbit papilloma. Staphylococcal bacteriophage has been shown to be a protein with a molecular weight of 500,000. These great discoveries not only shed a new light on the theory of virus diseases, but also bring us very close to the transition point betweenliving and non-living matter. If a pure chemical compound can exert all the functions of the simplest living organisms, then where are we to place the boundary line?
*Received for publication, September 31, 1937. The signs and symptoms of a case of typhus due to a rat virus are descibed. The distinguishing features between this variety of typhus occuring in Southern Africa are discussed.
Figures are given for the chance of infection, for the calcification rate and for the lethality of tuberculous infection among the European population and among the Chinese and Javanese labourers at Sumatra's Eastcoast. These figures are the results of a comparative pathological investigation by the author in Author in Europe and in the Dutch East Indies.