THE sulphur content of pastures has recently become a subject of considerable importance both from the point of view of sulphur fertilisation of soils [Alway, 1927] and in relation to the sulphur requirements of sheep for wool-production [Robertson and Marston, 1928]. The question of sulphur deficiency in soils has led to very thorough surveys of the total sulphur content of pastures in different parts of the world, but the organic sulphur content of pastures has received little or no attention. Nevertheless the separation of the total sulphur content of grasses into organic and inorganic components is important in seeking a correlation between the sulphur content of pastures and their value for purposes of wool-production, as only organic sulphur can be made use of by animals in biological synthesis. In the present paper, a method is described whereby the organic sulphur of pastures can be readily determined. It is assumed that all the inorganic sulphur in green leaves is in the form of sulphate, whether free or as ethereal sulphate. This sulphate-sulphur is therefore estimated and deducted from the total sulphur, giving a value for the organic sulphur.As regards the nature of the organic sulphur compounds in grass, they probably occur as constituents of protein. Woodman [1926] finds 27-92 % crude protein in autumn cuts of English grass, while Rigg and Askew [1929] find an average value of 33*37 % crude protein for eight samples of New Zealand pasture. "Crude protein" includes chlorophyll and other nonprotein nitrogen compounds, but the figures are of the right order to account for the organic sulphur present in grass, assuming that grass-protein contains the average amount of sulphur. In this connection it is to be noted that a water-soluble protein prepared from grass, as subsequently described, by the method of Chibnall and Schryver [1921] did not contain sulphur. This substance was a proteose, however, not a native protein, and it represented only a small proportion of the total nitrogen of the grass. Since protein-sulphur in grass would have to form part of an amino-acid, the question of the identity of this sulphur amino-acid immediately arises. Robertson and Marston [1928] apparently make a tacit assumption that the acid is cystine, this being the sulphur constituent of wool and also of widespread occurrence elsewhere in nature [Jones, Gersdorff and Moeller, 1924].

1. Most artificial manures are found to have some effect in increasing the iodine content of crops, particularly superphosphate.2. Marked differences are found between the iodine contents of Samoan and New Zealand foodstuffs corresponding to the non-goitrous condition of Samoa and the partial endemicity of New Zealand.3. Investigation of the dietaries of fifteen residential institutions showed that improvement in provision of iodine was necessary in many cases by using fish at least twice a week, raising the daily ration of milk to 1 pint per head, and employing iodised salt for table and culinary purposes.4. Dietetic experiments indicate (i) that on a change of diet adjustment of iodine metabolism may take a considerable time, (ii) that iodised salt is most effective in promoting storage of iodine when associated with a meat diet.5. Iodine excretion is found to decrease much more rapidly under fasting than on a diet very low in iodine.6. Iodised salt has the effect of adjusting the excretion of goitrous adults to the normal non-goitrous value.7. The iodine content of the blood is found to be lower than normal in cases of simple colloid and simple nodular goitre, though it may range from low to abnormally high in cases of Graves' disease. In all types of goitre the thyroid gland is low in iodine.8. The ratio of thyroid iodine to total bodily iodine is about 12 per cent. in the case of the white rat under ordinary conditions, but the ratio is found to vary considerably with the iodine intake.9. Great differences in the ratio of the weight of the thyroid gland to that of the whole body are found among different species of animals, the ratio being higher for the dog than for the monkey.10. Variations in commercial samples of iodised salts are recorded and discussed.11. Data are given in regard to the iodine and chlorine content of rainwater in different localities.

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1. Methods for the estimation of iodine in natural products are described.2. Common sea weeds on the Pacific coast of Otago have an iodine content of the same order as similar species on the Pacific coast of British Columbia.3. In Cystophora retroflexa, which contains over 0·1 per cent, of iodine, 70–80 per cent, of the iodine appears to be in inorganic or loosely bound combination. Precipitation and colour tests indicate that di-iodotyrosine is also present.4. Observations are recorded of the iodine content of kelp-feeding and other fish.5. Administration of anaesthetics produces fluctuations in the concentration of blood iodine in rabbits, the effect persisting after removal of the thyroid gland. Experiments in vitro suggest that only in the case of inorganic iodine could a redistribution of iodine between tissues and serum be brought about by the direct action of anaesthetics.6. New Zealand cabbage possesses goitrigenous properties for rabbits but in a much smaller degree than American cabbage.7. The urinary excretion of Samoans is compared with that of inhabitants of Christchurch Mental Hospital.8. The incidence and course of development of goitre at Christchurch Mental Hospital is discussed.9. Values are given for the iodine content of Otago pigs' thyroids.