The production of some toxic substance by cancer tissue has long been suspected, but due to the lack of adequate criterion, upon which to base the assay of such a substance, previous reports along this line added little substantial knowledge on the subject. Our recent experiments to be briefly described in this paper may be of interest in this connection.
The starting point of our experiments was furnished by the observations of Greenstein and his associates, who found that the liver catalase activity of tumor bearing, rats and mice was markedly reduced, and that the extirpation of the tumor caused the liver catalase to rapidly return to normal, re-implantation with tumor causing liver catalase to drop again. By demonstrating that tumor tissue has no direct action in vitro on liver catalase, they concluded that the tow liver catalase activity of tumor bearing animals is ascribable to the reduction in amount of total catalase present in liver.
A natural inference from these observations may be that tumor tissue produces some toxic substance which, acting upon liver cells, serves to reduce their catalase content. In the hands of Greenstein, however, tumor extracts injected intraperitoneally into normal rats produced no change in the liver catalase activity of these animals. This apparently paradoxical result can be explained only on the assumption that the toxic substance in question occurs in tumor tissue in a low concentration and it requires a very large quantity of an ordinary tumor extract to deliver a sufficient amount of the substance to affect the liver catalase activity. This difficulty may be overcome by concentrating the hypothetical toxic substance.

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About 20 years ago I reported a colour reaction given by arginine on the addition of α-naphtol and sodium hypochlorite to its alkaline solution. This reaction, which I recommended for the estimation of arginine, was notably improved by Weber by the use of hypobromite instead of hypochlorite. These methods have, however, a disadvantage in that α-naphtol and hypochlorite or hypobromite alone gradually produce a yellow colour which much interferes with the colouration given by arginine. In this commuication I am proposing the use of oxin instead of α-naphtol, as the former remains colourless on the mere addition of hypobromite.

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We have previously reported on the studies of the pattern of Japanese B encephalitis virus in mosquitoes (Culex pipiens var, pallens and Culex tryteniorhyncus), and various relationships between these species of mosquitoes and the virus, and concluded that Japanese B encephalitis virus which was sucked by mosquitoes reappered after a certain period of external incubation, and that the final concentration of the virus in mosquito bodies depends on the concentration of the virus in the first feeding to the mosquitoes. It was further concluded that the experimental transmission of the virus to mice through bite of these virus-sucking mosquitoes are only possible (10%) when the concentration of virus in the mosquito is high. We have considered, therefore, that there must be certain species of animals in nature, whose blood contained Japanese B encephalitis virus in high concentration as sources of the virus to these mosquitoes, if the latter had transmitted the virus in nature. In the same year (1941), W. McD. Hammon and W. C. Reeves in America, demonstrated the St. Louis virus and the western equine encephalomyelitis virus in the mosquitoes (Culex tarsalis), which were captured in Yakima Valley, Washington, and neutralizing antibodies in the blood of chickens in the same area, and proposed the hypothesis of infection cycle for these viruses (mosquito-chicken-mosquito) .
These authors later concluded however, that the chickens were i not true reservoirs or latent carriers, though the possibility had not been ruled out of an occasional fowl having an unusual course of infection, because the domestic birds such as chicken, ducks and doves could not maintain these viruses in the blood for a long period, and they could not domenstrate the viruses in hibernated mosquitoes or transovalian infection of these viruses and mosquitoes.
From the results of our foundamental experiments on the relationships between mosquitoes and J apanese B encephalitis virus and of the studies carried out by Hammon et al. in America, we thought that it was necessary to search for the reservoir of Japanese B encephalitis virus in Japan, from the standpoint of epidemiology and of prophylaxis against this disease. In the summer of 1947, Dr. Hammon, Dr. Casals and Dr. Meiklejohn came to Japan and, after a conference with these investigaters, and with the Virus and Rickettsia Committee of G. H. Q., staff of 406th Gen. Med. Lab. and N. I. H, it was decided to carry out the studies herein reported. We are indepted to Dr. W. McD. Hammon, Dr. J: Casals, Dr. G. Meiklejohn, Mr. Austine, Dr. H. Hamlin and Dr. Uchida for many valuable suggestions and assistance in our studies.

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Since August, 1943, we have been studying a fairly large number of Salmonella strains isolated in various parts of East Asia Tropical Regions, e. g., Malay, Java, Sumatra, Burma, Siam, French-Indochina, the Philippines, etc.
Amongst them we found a strain, isolated from a case of enteritis, in Singapore, very close to S. thompson. But on further investigation, its non-specific phase factor was found to have enx antigen instead of 1.5......, thus having the antigenic structure, VI. VII: K-enx.
We here report on this new type of Salmonella (Singapore) .

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Principles of the extraction process of penicillin such as the solvent process and the charcoal adsorption process were found before the end of the second world war in Japan (1), but it was since November 1946, when Foster came to Japan, to undertake the systematic studies of the extraction.
At about the beginning of our study, the recovery of penicillin from the broth to the packaging in a final container in Japanese factories fluctuated between 10-40%, but now it increased to 50-80%. This increase is completely ascribable to the systematic and elaborate examinations of all the stages in the extraction process, not but to the change of the principles.
In the present paper the experiments and results concerning each stage of the extraction are described.

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Since we undertook the studies on streptomycin, various kinds of actinomyces producing substances resembling streptomycin were isolated (1, 2), and we were thrown into confusion, as to which one of them was streptomycin. The difficulties of the isolation of streptomycin-producing strain seem to be ascribable to the existence of many kinds of actinomyces producing other substances resembling streptomycin. which, in the broth, inhibit B. coli and other gram negative bacteria rather more strongly than streptomycin.
Streptomycin, streptothricin (3) and allied substances are usually differentiated on the basis of their antibacterial spectra, but this differentiation method can only be utilized in laboratories, where streptomycin, streptothricin and other related substances are already isolated, since even among the same species the resistance of bacteria may be different in different individual strains.
Recently Waksman, Reilly, ahd Jonstone (4) reported that streptomycin-producing strain was much more resistant against streptomycin and the incorporation of streptomycin in the isolating medium in concentration sufficient to inhibit the growth of the usual actinomyces facilitated the isolation of streptomycin strain. Among 120 antibiotic strains of various kinds of actinomyces isolated by us, 21 strains grew on the nutrient agar plus 50 μg of streptomycin hydrochloride (Merck's sample, about 600 μ/mg) and from one of them streptomycin was extracted and purified as its reineckate crystal. This and other strains producing related substances and the antibiotic substances extracted from them were comparatively studied, and it was concluded that among these substances streptomycin was particular in respect of the tolerance of streptomycin-fast bacteria and the colour of its Sakaguchi's reaction, though they were all similar in extractability and solubility, and inhibited both gram positive and negative bacteria.
Now we should like to devide the antibiotic substances resembling, streptomycin and streptothricin into streptomycin and streptothricin-group substances, among the latter streptothricin having been first isolated by Waksman and others (3) . Lavendulin and actinorubin found by Kelner and Morton (5) and basic antibiotic substances resembling a streptomycin and streptothricin reported by us (1, 2) are to be included in streptothricin-group substances, for the streptothricin-fast B. coil is nearly as susceptible to these substances as the normal culture. Streptin found by Foster and others (6) also seems to belong to the streptothricin-group substances, for it is extracted in the same way as streptomycin from the broth of A, reticulus-ruber, which was found by us to produce a streptothricin group: substances and a streptomycin-producing strain is not yet found in species other than S. griseus.
On account of the possible differentiation of streptomycin from allied substances and also of the important discovery by Waksman and others (4), showing the specific tolerance of streptomycin-producing strain against streptomycin, the isolation of the streptomycin strain became much easier.
In the present paper method for the differentiation of streptomycin and strepthothricin-graup substances and the rapid isolation and identification of streptomycin-producing strain are described.

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To meet the urgent need during the recent epidemic of smallpox the greatest effort has been made by workers in the Lymph-Department of Government Institute for Infectious Diseases, to prepare smallpox vaccine.
Since, at the time, almost all the Lymph-Laboratories were deprived of their own working places and equipments owing to the sudden termination of the War, there was no other way than to do our duty to the best of our ability.
The present paper describes the procedures, with which we produced the smallpox-vaccine for 30, 000, 000 personnels within a 3 months period.

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Numerous strains of streptomyces, producing antibiotic substances in the ordinary nutrient agar and inhibiting the growth of the bacteria around their colonies, have been isolated from soil, and actinomycin A (1), streptothricin-group substances (2), and streptomycin (2) have been extracted in our laboratory. But the streptothricin-group substances were produced by so many kinds of streptomyces and their culture filtrate inhibited so strongly the growth of bacteria, that the isolation of new antibiotic substance inhibiting both gram positive and negative bacteria had been very difficult, until recently a simple method determining an antibiotic of streptothricin-group substance was, found (2) . A streptothricin-fast strain of bacteria becomes not only more resistant against the other streptothricin-group substances but also against streptomycin, and a streptomycin-fast strain is nearly as susceptible to the streptothricin-group substances as the normal culture.
In our further search for a new antibiotic, it was found that there was an antibiotic inhibiting both the gram negative and positive bacteria, but different from streptomycin and streptothricin-group, for it could be extracted with ether or ethyl acetate, and neither the streptomycin-fast strain nor the streptothricin-group-fast strain became more resistant to it.
While studying this antibiotic substance, we noticed the papers concerning chloromycetin. Chloromycetin was found independently by two groups of American antibiotists, the one, Smith, Joslyn, Gruzit, Mclean, Penner and Ehrlich (3) obtained a chloromycetin-producing Strain after examining numerous organisms isolated and found to possess antibacterial activity in Dr. Burkholder's laboratory, and the other group, Carter, Gottlieb and Anderson (3) isolated the strain from the soil in central Illinois. It is produced in the maltose or glycerol roth and extracted with ethyl acetate at various pH and inhibits not only the growth of both gram negative and positive bacteria but also the growth of rickettsia. The proposed name, chloromycetin, seems to originate in the existence of non-ionic chlorine in the molecule.
The characters of the ethyl acetate-soluble antibiotic found by us very closely resembled chloromycetin, so we studied this substance along the line of the experimental process described by Smith and others (3) and Bartz (4), and obtained the crystalline antibiotic, the melting point of which conformed with that of chloromycetin.
This paper describes the isolation of the strain, some studies on the cultural conditions and the purification. The details on the characters of the strain, the cultural conditions, and the chemical nature of the crystalline antibiotic substances will be published elsewhere.

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