VI. MIXED FERTILIZERS.

MIXTURES CONTAINING PHOSPHORIC ACID AND POTASH.

Two samples in which only phosphoric acid and potash were guaranteed were analyzed.

96. Buffalo Phosphate and Potash. International Agricultural Corporation, Boston.

19. Olds and Whipple Bone Phosphate and Potash Compound. Olds and Whipple, Inc., Hartford.

Both samples were drawn by the Station agent. Analyses are as follows:

Three samples which contain no potash have been analyzed. 36. Olds and Whipple Top Dressing for Grass, 7-4-0. Sampled by Station agent from stock of F. T. Blish Hardware Co., South Manchester.

23198. Olds and Whipple High Grade Tobacco Starter. Olds and Whipple, Inc., Hartford. Sampled by Station agent from stock of E. O. Gates, Pine Meadow.

23061. Shoemaker's Swift-Sure Tobacco Starter, 4-10-0. Sampled by Station agent from stock of F. S. Bidwell & Co., Windsor Locks.

In both these samples the active insoluble organic nitrogen

was of good quality as judged by the usual methods.

MIXTURES CONTAINING AMMONIA, PHOSPHORIC ACID AND POTASH.

In Table XIV are given analyses of two hundred and ninetynine samples of complete fertilizers. Two hundred and eightytwo were drawn officially by the Station agent and seventeen were submitted by purchasers.

In the column headed "grade" appear the figures which represent the guaranteed amounts of ammonia, available phosphoric acid and potash in the order named; thus, 4-8-4 means that the brand is guaranteed to contain 4 per cent of ammonia, 8 per cent of available phosphoric acid and 4 per cent of potash. In the analyses on the right hand pages of the table the corresponding percentages of these constituents as found appear in bold face type.

CONCERNING GUARANTIES.

Of the two hundred and eighty-two official samples, one hundred and twenty, or about 40 per cent, failed to completely satisfy their guaranties, deficiencies of 0.12 per cent in ammonia, 0.2 per cent in available phosphoric acid and 0.15 per cent in potash being disregarded. Each sample requires three major determinations in order to check the guaranty, hence eight hundred and fortysix determinations have been required for the official samples in this group. Since some samples have been deficient in more than one item, the total number of deficiencies found was one hundred and forty-nine; in other words, about 82.4 per cent of the individual items of plant food guaranteed have been substantially correct or in excess of guaranties.

Taking the total number of samples of each manufacturer who registered three or more brands, and calculating from the analyses the average shortage or overrun in elements of plant food guaranteed, we deduce the following summary:

Of 26 manufacturers,

16 equaled or exceeded guaranties in the three elements.
9 equaled or exceeded guaranties in two elements and were
short in one.

1 equaled or exceeded the guaranty in one element and was
short in two.

Nine of the shortages were in ammonia and there was one each in available phosphoric acid and potash. The ammonia deficiencies ranged from 0.10 to 0.53 per cent; seven were less than 0.25 per cent. The deficiencies in available phosphoric acid and potash were 0.15 and 0.19 per cent respectively.

ANALYSES REQUIRING SPECIAL COMMENT. Special comment or explanation is due in connection with the following analyses:

185. Aben Hardware Co. This sample represents a part of a cargo of fertilizer salvaged from a wrecked vessel. The goods were found to be under guaranty but they were sold for a price at which the purchaser suffered no loss.

158. Am. Agr. Chem. Co., 3-8-4. The manufacturer obtained 3.74 per cent of potash on a duplicate portion of our sample. Our report for potash was 3.71 per cent. On 159, 5-8-7 of the same manufacturer, their result for potash was 6.71 per cent; our report was 6.50 per cent.

Five of the Armour brands have shown considerable deficiencies. Second samples were analyzed in nearly all cases.

23398. Atlantic Tobacco Manure 5-8-6. This was found below guaranty in ammonia; a second sample, 172, from another source, was also low. The results for the two samples were 4.44 and 4.77 respectively.

23125. Berkshire Complete Tobacco 5-3-5. This showed 4.83 per cent ammonia but a second sample, 5, from another source showed 5.22 per cent. The average analysis for the two samples is 5.03-3.89-5.78, which meets the guaranty.

23301. This sample was drawn as Chittenden's Top Dresser 6-8-4, but analysis showed it to be a 4-8-4 brand. Investigation was made but it could not be determined beyond doubt whether Potato Manure was packed in bags marked "Top Dresser" or whether an error in sampling had occurred. A second sample could not be obtained from this or any other purchaser and the sample is, therefore, accepted as a 4-8-4 brand.

23392. Clark's Special Mixture, 4-8-4, was reported low in ammonia and potash, but a second sample, 299, was found to meet the guaranty. The average of the two analyses is 3.78-8.69-3.99 which satisfies the guaranty, except in ammonia, and shows no significant deficiency in money value.

23038. Frisbie's Special 3-8-4, was reported low in total phosphoric acid; a second sample, 23305, was below guaranty in total phosphoric acid and in potash. Available phosphoric acid was satisfactory in both cases. The average for the two samples is 2.94-8.17-3.82.

22992. Frisbie's 4-8-4 was reported low in ammonia and potash; the second sample, 23274, was likewise deficient. The average for the two analyses is 3.76-8.51-3.73.

22990. Frisbie's 5-8-7 was low in ammonia, and the second sample, 23273, was deficient in ammonia and potash. The average of the two analyses was 4.70-8.85-6.79.

22984. Frisbie's 7-5-4 was reported low in ammonia, and the second sample, 162, was also below guaranty in this respect. The average of both analyses is 6.52-5.65-4.10.

23037. Lowell 5-8-7, and 23041, Lowell 4-8-4. These two samples were found to be below guaranty in ammonia. Portions of our samples were submitted to the manufacturer and the check results were in close agreement with our figures.

23243. Lowell Tobacco 5-4-5 was found low in ammonia but the second sample, 8, was not deficient. The average of two analyses is 4.87-5.05-5.26.

23154. Naco Brand 2-8-2. This brand is called 2-8-2 but its actual guaranty is 2.8-11.3-2.8, the idea being that the purchaser is to understand that a pound of this brand will contain the same amount of plant food as one and 2/5 pounds of a 2-8-2 grade. Several other brands of the Nitrate Agencies goods are listed on this "equivalent" plan. Registrations, however, should declare the percentage amounts of elements in the goods as sold. To have the brand indicate one grade and the analysis another leads only to confusion.

23060. Royster's Top Dresser 7-6-5 was found to be low in ammonia. Analysis of a duplicate portion of our sample by the manufacturer confirmed our result.

23189. Virginia-Carolina 4-8-6; 23193, 3-9-5; and 92, 8-6-6. Duplicate portions of our samples were sent to the manufacturer and their results were in substantial accord with ours in all cases.

The Rogers and Hubbard Co. advise us that very discordant results for available phosphoric acid have been reported to them by control and by commercial laboratories on their bone-base goods. In this connection it should be noted that so-called "available" phosphoric acid is largely influenced by the method of determining citrate-insoluble phosphoric acid, which method was devised for use upon acid phosphate and which does not accurately evaluate phosphoric acid from other sources such as bone, tankage, etc.

DEFICIENCIES IN MONEY VALUE.

In eighteen brands deficiencies have amounted to more than a dollar per ton, the values being arrived at by balancing overruns against shortages and reckoning ammonia at 21 cents per pound and available phosphoric acid and potash each at 4 cents per pound. Where more than one sample of a given brand has been analyzed the commercial shortage has been estimated on the basis of the average of the analyses made. The brands thus found deficient are listed in Table XV.