1. 1. Paris green was used as a larvicide on an inland hilly estate where A. maculatus was the carrier-and where most of the water treated was moving, more or less rapidly. 2. 2. Three different diluents were tried, viz., lime, talcum and soapstone powder. 3. 3. The strength of the mixture was one part of Paris green to ninety-nine parts of diluent by volume. 4. 4. Distribution was carried out by mechanical blowers and sprayers. 5. 5. The application was checked twenty-four hours afterwards. For one month it was checked forty-eight hours afterwards. 6. 6. There was an increase in breeding places-most of which were found in moving water. 7. 7. There was an increase in larvæ, many of them being over two days old. 8. 8. In spite of treatment of epidemics with plasmochin and quinine, the malaria rate was higher than during the previous year. The rise was more or less consistent, pointing to constant infections. 9. 9. The morbidity rate, death rate and infantile mortality were apparently not adversely affected, but in view of the treatments given with plasmochin, they are of no help in deciding the value of Paris green. 10. 10. There was a distinct fall in anti-larval costs, but the total anti-malarial costs were still high on account of the treatments necessary for epidemics of malaria. 11. 11. The advantages and disadvantages of Paris green are discussed.
One of the factors on which the incidence of leptospirosis is dependent is the survival time of shed leptospires in surface water or soil water, and this time is in turn affected by the acidity or alkalinity of the water. The authors have therefore studied the survival of four leptospiral serotypes in buffered distilled water at pH's ranging from 5.3 to 8.0. All survived longer in alkaline than in acid water, and significant differences between the serotypes were found in response to pH. Survival at pH's under 7.0 ranged from 10 to 117 days and at pH's over 7.0 from 21 to 152 days. Survival was also studied in aqueous extracts of soil samples from different areas in Malaya; no correlation was found between pH and survival time.It was also noted that in a group of Malayan ricefields a low incidence of leptospirosis in man was accompanied by a high infection rate among rodents, and when it was found that this phenomenon could not be explained by pH or salinity, attention was turned to the soil. Bentonite clay, similar to the montmorrillonite clay of the ricefields, was found to adsorb about half the leptospires in suspension. The authors recommend that field study of this laboratory observation be undertaken.
1. A skin lesion was made in rats by dorsal incision and the insertion of a polythene tube. 2. Over a period of 25 days after wounding, assays were performed for ascorbic acid, DNA, hydroxyproline, methionine, tryptophan, tyrosine and free amino acids in the lesion tissue. 3. The neutral-salt-soluble proteins of the lesion tissue were fractionated on DEAE-Sephadex, with the separation of fibrinogen and gamma-globulin from a serum protein fraction. 4. Over a period of 20 days after wounding, in wounded rats and in controls, assays were conducted for: ascorbic acid in lens and liver, hydroxyproline, soluble protein, methionine and water in muscle and tendon, and free amino acids in muscle. 5. Relative to controls there was a decrease in lens and liver ascorbic acid, a rise in tendon hydroxyproline, a rise in muscle free amino acids, a fall in muscle protein and a rise in tendon and muscle water.