444 Transactions. —Chemistry. 
from grit and fit for the potter without elutriation. In the Wade District, 
extending to Riverhead, we have a very varied assortment of clays, fit for 
all purposes of pottery material with the exception of the finer wares. From 
Mercury Bay I have received samples of fine, white, unctuous clays, but as 
to the extent of the deposits I have no information. In the Waikato, near 
Hamilton, there are some excellent clays, the biscuit of which is of a pure 
white. Some of these clays have been worked up into medallions, slabs, 
and ornaments by Mr. Wright, who has resided a long period in that por- 
tion of the district engaged on pottery work, and whose workmanship is in 
the highest degree ornate. Though these clays are so excellent they have 
not been proved as to extent, and I think it questionable whether they will 
be found free from iron in more than small deposits. And here we have 
the drawback at present of lengthy rail carriage to the centre of population 
in the district. At the coal mines, Kawakawa, Whangarei, Taupiri, and 
Miranda, we have the refractory clays accompanying the coal measures, but 
these will be of value only in the rougher articles of pottery, owing to the 
presence of iron pyrites in nodules or finely distributed, and shrinkage, from 
the amount of bituminous material present. I come now to the last of the 
locations where I have found any great extent of clays for varied purposes, 
and so situated as to be within reasonable distance of fuel and adjacent to 
this city where the articles may be brought to market and for export. I 
allude to the Drury and Papakura, basin, overlying which are the plastic 
clays. Here, over several square miles of country, we have clays from the 
whitest material, giving a biscuit of great purity to yellow, grey and blue 
clays yielding biscuits from a light cream to a deep rich red, which will give 
a terra cotta of great beauty. I have analyzed some of these deposits, and 
here append the results :— 
Yellow Red Clay Blue Clay (pinkish 
(terra cotta). creamy biscuit), 
Silica .. 4 de eS 
Alumina M» A» ee 299 29:5 
Oxide of Iron .. da «uti DI 6:3 
Lime .. "e y. e+ trace trace 
Magnesia a $* .. trace ‘6 
Water .. e i a 19 16 
100:0 100:0 
In reference to these deposits, 1 do not for a moment claim any dis- 
covery with respect to them, as Dr. Hochstetter, in a lecture delivered at 
the Mechanics' Institute in 1859, calls attention to these beds, advising the 
establishment of potteries for the manufacture of earthenware, and further 
states “remarkably suitable clays of every necessary variety have been 
shown to exist in the neighbourhood,” and also furnishes the results of two 
