Page:Transactions and Proceedings of the New Zealand Institute - Volume 1 (2nd ed.).djvu/506

470 1. "Description of Arid Island," by Captain Hutton and T. Kirk. (Transactions, p. 108.)

At the conclusion of the paper, which was read by the honorary secretary, Mr. Gillies, some discussion took place respecting what had been stated as to the subsidence of the island. Dr. Purchas, Mr. Gillies, Mr. Boardman, and Captain Hutton spoke on the subject.

2. "On Agricultural Chemistry," by J. Lowe, C.E.

The author commenced by observing that the fertility of a soil, as relates to the production of particular crops, may depend upon the presence or absence of very minute or almost imperceptible portions of inorganic substances—alkalies for instance—and salts of metals. The necessity, for example, of sulphate of lime to clover, silica to grapes, phosphorus to wheat, &c., was formerly quite disregarded, and it is only of late years that these matters have been more looked into; and we see, with satisfaction, the result of the joint labour of the farmer and the chemist. Soils are made up of organic and inorganic constituents; he would confine himself to the latter, and class them as those which constitute the bulk of the soil, on the mechanical texture of which the growing crops depend, such as clay, sand, and lime; also those involving the fitness of soil for particular crops, such as sulphate and phosphate of lime, soda, ammonia, magnesia, &c. The author described various mineral and chemical compounds suitable for the different kinds of soils and crops; also the method for making and applying such. He described at some length the different kinds of clays and earths, and the properties peculiar to them, and recommended farmers to have their lands chemically tested or analyzed, so as to enable them, by applying the necessary compounds, to make the soil suitable for particular crops.

Captain Hutton said that in anticipation of the paper, he had prepared a map showing where limestone existed in the province. It would be seen that it occurred all over the north, in small patches, but the only great mass was in that part from Raglan Harbour to Aotea, Kawhia, and Mokau. As to the value of limestone as a manure, he should like to ask Mr. Wark what was done with the refuse lime from the gasworks, which was a most valuable manure.

Mr. Wark said that when the gasworks were first started, lime was used to purify the gas; but it had been found expensive, and he (Mr. Wark) now used oxide of iron, which cost three farthings, while the lime had cost sixpence. While the lime was being used, it was readily bought by the farmers at two shillings and sixpence per load. A good deal of ammonia had been given to farmers gratuitously, but he had not heard of the result.