31

H.—29

CHEMISTRY SECTION. REPORT OF B. C. ASTON, CHEMIST. The work of the past year shows an increase in the number of samples received in all branches, except in the routine examination of butter for water content. The latter work has now been taken over by the Dairy Division, Samples being sent to this Laboratory only when there is a likelihood of legal proceedings being taken. All members of the staff have given good and loyal service. Those officers who are attending Victoria University College have been successful in passing the College and University examinations which they sat for, and have obtained favourable reports from the professors. Soil Survey. This work has occupied the greater part of the time of the staff during the year, and 187 further samples were collected personally by the officers of the Laboratory, the work having in general been confined to the soils of the Rotorua district. In addition to these soils fifty-seven samples have been received from Field Officers of the Department, and sixty-one samples from other sources. A series of samples of typical Wellington soils has been supplied to Professor Benson, Otago University, in connection with research work on the occurrence of goitre in New Zealand. A topographical survey of the Rotorua district is at present being carried out by the Survey Department, and the results, when completed, will be of great assistance in connection with the soil survey of the same district which is being under taken by this Laboratory. Bush Sickness. The research on " iron starvation " or bush sickness, has been continued. The results of the past five years' work at Mamaku Farm were summarized and published in the Department's Journal for April, 1924. The Laboratory work for the same period has also been summarized, and articles on the results obtained appeared in the Journal for May, June, July, and August, 1924. Several visits have been paid to Mamaku and the surrounding district, and further experimental work with curative medicines and with methods of soil-treatment has been put under way. Malnutrition of Sheep in South Canterbury. In June, 1924, it was reported by the Live-stock Division that there was a difficulty in raising and fattening sheep on certain river-terrace lands in South Canterbury. These were stated to grow beautiful pasture, including clover, but after weaning-time the ewes picked up very slowly, or fell back in condition, scouring badly. Lambs grew very slowly. It was reported that similar difficulties had been experienced with cattle. The trouble occurred mainly at the time of flush of green pasture in spring. The matter was gone into on the spot by an officer of the Laboratory in company with the local Government Veterinarian. Representative samples of soil were taken from both upper and lower terraces. Chemical analysis showed that these soils were plentifully supplied with plant-foods, especially phosphoric acid and lime, but were deficient in " available " iron. The following treatment on an experimental scale was advised : Increase of soil-moisture by irrigation ; ploughing-in of green crops ; application of sulphate of iron to the soil, and feeding of iron ammonium citrate to the stock either in the form of a lick or as treated hay. No report as to the success or otherwise of the treatments is yet available. Investigation oe Wheat and its Products. A further series of wheat-samples has been experimentally milled and tested during the past year. The varieties tested differed from those received previously, consisting for the most part of lesser-known varieties. Three samples of Yeoman were milled. This is a comparatively new variety, bred at Cambridge, which is stated to crop heavily when grown on typical wheat-lands in England ; in addition it has been found to be of sufficient strength to enable it to compete favourably with the good breadmaking wheats imported from abroad. The miscellaneous samples were remarkable for their average very good strength. Most of these were grown at the Ashburton Experimental Farm, and contained an amount of gluten much above the average. Whether this is due to environment, the varieties themselves, or the growing season experienced in the summer of 1923-24, only the testing of further samples from future harvests will show. Amongst the total miscellaneous samples, the following contained very good amounts of gluten of good quality and were good strong samples : Essex Conqueror, Marquis, Jumbuck, Red Fife, Red Straw, and Queen Fan. Amongst the medium-strong samples were Zealand, Queen Fair, Hybrid W., Burbank's Super, and Turretfield Eclipse. Of the better-known varieties it was found that the samples of Velvet again maintained a very good average as regards quality. The strength of various Tuscans showed considerable improvement, and this year the average was very good. Victor again proved to be a wheat giving very good yields of flour but of inferior strength Dreadnought was again a good medium-strong wheat. The weight per bushel of the above wheats was calculated, and should prove of interest when compared with the other properties of the different samples. Contrary to • results obtained elsewhere, no close correlation between weight per bushel and yield of flour was observed. Nor did there appear to be any connection between weight per bushel and the quality of the grain, or the quantity of the gluten present in the flour.