74 
in Norway. This product is obtained on the principal that at 
the extreme heat of 3000 degrees, Centrigrade, atmospheric 
Nitrogen can be made to directly combine with Oxygen. Al- 
though this fact has long been known, the intense temperature 
required has been against the general adoption of the process, but 
by the use of the electric arc flame it is now operated on a large 
scale. The chemical combination of Nitrogen and Oxygen thus 
achieved produces Nitric Acid gas. This compound is after- 
wards passed through absorption towers through which water 
and milk of lime flow. The resulting liquid obtained is then 
evaporated and solid Nitrate of Lime (calcium nitrate) is ob- 
tained. 
The Notodden plant was established in 1903. It possesses 
three furnaces ,each producing 250 tons of nitric, acid per 
annum, which yield about 325 tons of calcium nitrate. The 
factory therefore turns out approximately one thousand tons of 
fertilizer per year, but another plant of twenty times this ca- 
pacity is soon to be erected. Licenses for the Birkeland and 
Eyde process are granted by the Aktieselskabet Notodden Sal- 
peterfabrik, Christiania, Sweden. Many plants are at work in 
Europe on the manufacture of Calcium Nitrate by this patent, 
although Norway is more forward in this respect than other 
countries. At Rjukanfos, a factory is being constructed where 
250,000 h. p. is available from water power. 
In the Birkeland and Eyde process, also, a great improvement 
has lately been introduced by which the percentage of Nitrogen 
is increased and the hygroscopic properties of the product is re- 
duced. 
In the Hawaiian Islands there is without doubt a splendid op- 
portunity for the manufacture of either Calcium Cyanamide or 
Calcium Nitrate. The enormous and growing quantity of fer- 
tilizers required by the cane fields, the anticipated reduction of 
the output of natural nitrogenous compounds, and many other 
circumstances hold" out to the manufacturer of the new products 
a most promising investment. The available water supply of 
the Kauai mountains naturally would suggest that island as the 
most appropriate site for such an enterprise, although there are 
without doubt throughout the islands other available sources of 
water power. In the near future we predict the introduction to 
the Hawaiian Islands of one of the processes briefly described 
and we hope that such an undertaking will be prosecuted with 
Hawaiian capital. 
The following letter from the United States Department of 
Agriculture was recently elicited in response to a request by a 
correspondent in the Islands who desired information on this sub- 
ject : 
