not possessed by present methods. Whether the technology of this operation can be satisfactorily solved remains to be seen. Results so far obtained offer the distinct promise that no insuperable difficulties will be encountered. The advantages offered would appear to justify any effort required to reduce the proposal to practical terms. The working margin between cost of raw materials and the sales value of the finished product is $21 per ton of phosphate rock in the use of nitric oxide as compared with $3.50 in the use of sulfuric acid. How much of this spread will be consumed by operating costs will depend on the skill of the technologist. Synthetic ammonia is regarded as the keynote in the concentrated fertilizer symphony but there are those who feel that liquid phosphoric acid shares that honor. A compromise may be found in the position that both are essential. Certainly, with the two the entire concentrated fertilizer program may be brought to realization. Synthetic ammonia is an accomplished fact, available a t prices below fertilizer values. The same statement cannot yet be made with respect to phosphoric acid if we restrict our consideration to the domestic situation. What has been done abroad we can do here and will do when and if it suits our purposes. In the meantime, we are proceeding logically with our concentrated fertilizer program, taking the initial steps toward more concentrated mixtures with the materials already available and with these preliminary mixtures gaining the experience necessary before 'proceeding to the most concentrated. The technic of manufacture and of distribution is being studied. Field tests are being conducted. A noteworthy tonnage of fertilizers analyzing 60 per cent plant food is being marketed. The low analysis mixtures only a few years ago regarded as the standard are now disappearing from the market. The freight bill paid to move the 7 million tons of fertilizer used annually in American agriculture amounts to approximately $20,000,000. The sacks used to contain i t cost an additional $12,000,000, a total of $32,000,000 to be cut in two with the doubling in the plant food content of prepared fertilizers from 15 to 30, or from 20 to 40 per cent. The limit does not have to be reached before the benefits begin to accrue. Each step brings its own reward.
Diatomaceous Earth. Diatomite bas hitherto been mined only in vely small quantities in Nova Scatia, but it is likely before very long to become a product of some importance in Canada. Recently a deposit of large magnitude, stated to be the richest in eastern Canada, bas been under development at Digby Neck. Diatomaceous earth has for many years been extracted in small quantities by the Oxford Tripoli Sales Company in Cdchester County, and the Company has also installed a new plant at East New Annand where they have located four large bogs containing a big tonnage of diatomite.-Chsm. N m s , 138, 116 (Feb. 22, 1929).
