Navassa/Report of Dr. G. A. Liebig

To the Corporation of the
Navassa Phosphate Company of New York:
Walter E. Lawton, Esq., Treasurer.

Sirs:

Amongst the different fertilizers imported from distant localities for the wants of Agriculture, the divers varieties of Guano, by their powerful influence upon the crops, and the easy manner of application, have justly been kept in high estimation by the farmers, and found an extensive market.

Under this name, other substances not less beneficial to the culture of plants and cereals, have been introduced as Phosphatic Guanos—the earthy debris of birds' deposits—and for a number of years the islands in the Caribbean Sea, the Gulf of Mexico, along the coast of South America, have been the main source of supply of this article, so important for the agricultural development of our country. By furnishing to the manufacture of concentrated manures a chief material, containing a large proportion of phosphoric acid, an agent mostly derived from animal substances, and consequently of expensive origin, they were the means of restoring and exalting the fertility of exhausted and worn out lands; have increased our agricultural products, and thus largely contributed to our general welfare.

It has been ascertained that the importation into this country of this material during the last ten years, since its first introduction—amounted to upwards of a hundred thousand (100,000) tons; but however large this sum appears to be, it will fall into insignificance, when compared with the resources of the island of Navassa, of a valuable phosphate to the agricultural community at large and the manufacture of fertilizers in particular.

The exploration of this island could not have been made at a more propitious time, and opens a new era in the production of ​fertilizers; our inability to collect a sufficiency of stable manure, and the almost exhausted state of the localities of the above named phosphates, have rendered most opportune the discovery of an immense formation of mineral phosphate for the daily increasing manufacture of fertilizers, which scarcely covers the demand.

Of the history of Navassa not much can be said, as only traces were found, to indicate that it, at one time, offered a temporary abode to some Indian tribe. In the year 1856, Captain E. K. Cooper discovered the island, and his since been in the indisputed possession of it.

Situated in 18° 25′ north latitude, and 76° 5′ west of Greenwich, southwest of St. Domingo and east of Jamaica, it presents itself, seen from the windward, as a perpendicular rocky mass of about three miles in length, rising some three hundred feet above the level of the sea. Its base widens to the south-west, and extends from south to north-west to a low flat level, which, almost a plain, stretches in its southern extremity about one mile out into the ocean. The whole of the island is, with little exception, covered with a luxuriant vegetation of dese woods and grass. Different species of the palm trees, viz: Sabal Paltmetto, Areca oleracea, etc.: several varieties of Cactus, some of immense sizes—vines and other climbing plants, give the whole the character of a true tropical landscape.

The island is inhabited by about forty white men, who, under the management of Captain Louis, work the place, and are provided with all the necessary accommodations.

The rock, which constitutes the island, is a hard white globuliforme limestone, which, from the numerous fissures found in it, is evidently a Jurassic limestone. It is full of cliffs and fissures and interstratified with numerous layers of phosphate of lime, the outcroppings of which, on all parts of the island, make such splendid show, that even a casual observer cannot fail to disclose the fact of an almost inexhaustible deposit of this mineral. The strata and layers, the exact number of which, on account of only parts of the island being cleared of the wood, could not be ascertained, vary in thickness and their physical properties, hardness, specific gravity and color, (from the light yellow to the dark brown,) and differ consequently in their chemical constitution.

​Under the lens, this mineral appears as a conglomerate of round globules of phosphate of lime, coated with a thin crust of oxide of iron and imbedded in a solid mass, which, in the darker specimens consists also of phosphate of lime.

The analysis below, made of samples of different colors, which I collected myself, will show, that this mineral, whilst it contains a uniformly high per centage of phosphoric acid, is in some parts of the island richer in phosphate of lime than in others, where the amount of phosphate of iron and alumina is larger than in the former.

The richest specimens being obtained from below the surface, demonstrate that it improves with the depth.

Again, there are some layers which have a bright rusty color, rough texture and are very friable. In these the globules are not so close together, and the mass in which they are imbedded is almost pure oxide of iron.

These exposed for thousands of years, as they undoubtedly have been, to the atmospheric action, rain, etc., became disintegrated and loose, have gradually filled the cavities of the limestone rock, and thus formed the soft deposit, with which the upper flat of the island, some one thousand acres, is covered.

From this loose mass the first shipments into the Baltimore market were made. It was introduced under the name of Navassa Guano as such it was known, until Dr. Campbell Morphit, in his treatise on the different Guanos, (see American Farmer, Vol. II, No. IV.) pronounced it for the first time to be a mineral phosphate. It is a more or less coarse powder, of a rusty color, and otherwise well enough known at present, as to need further description.

This deposit, of which about four to five thousand tons are dug and ready for shipment, is, as seen by the analysis, the must inferior found on the island, but, I am glad to say, it forms also the smaller portion to be worked. By a proper process, however, it can be improved, raised to 64–65 per cent. of phosphate of lime, and thus made marketable, if desired.

While speaking of this upperland, I cannot neglect to mention the existence of a number of caves there of various sizes, the bottoms of which are covered with a fine grayish looking substance, widely different in its character from the other de​posits. It is very soft, sparingly mixed with globular grains, ail yields a high amount of phosphate of lime with some magnesia phosphate. As it contains perceptible traces of nitrogenous organic matter, it seems to be of animal origin, similar to that of Mexican Guano. A sample representing a pile of twenty tons, collected in a cave of about 10' length, which I visited myself, shows almost 50 per cent. of lime-phosphate, thus proving it to be a valuable article worthy of consideration.

The lower that land, which is by far the largest of the two, covering scarcely less than two thousand acres, is the great depot to which I wish to call your attention.

Being accessible with but little outlay of capital, and furnishing at a low calculation one thousand tons to the acre, it will constitute, independent of the rocky phosphate, for a grout number of years the main source of supply for the trade.

This deposit, the product of disintegration of the richer layers, has the same globular formation, but the globules are larger, the coating is thinner and consists of alumina with some silicates. It is of light brown color and analyses from 62 to 72 per cent. of phosphate of lime, and will be a desirable material for the manufacturer.

From the peculiar formation, and the presence of free exile of iron, it is fair to suppose that the phosphate of lime of the Navassa Island, originated from phosphate of iron and alumina, which alternating with strata of limestone, were gradually transformed into phosphate of lime. This supposition is corroborated by the large quantity of oxide of iron which is found in many places of the island, and had been set free during the process of transformation by the lime of the limestone.

I have to express here the regret, that during my exploration of the island, I did not find any crystals of this phosphate, as from my analysis I am strongly inclined to consider it a new mineral, which I should propose to call "Navassite," if my suppositions were confirmed by subsequent examinations of the chemical and crystallographic characters of more perfect specimens.

But if I have to leave for the present this question of scientific interest without solution, I am happy to record here the discovery, I may say, of an inexhaustible quantity of a mineral substance, the phosphate of lime, so instrumental in the development of agricultural wealth.

​The fact that phosphoric acid is an indispensable agent to the maintenance of vegetable life and the formation of grain, be coming daily more understood by the farmer, I think it needless to dwell further on this subject, or to speak of the benefit derived from the application of phosphatic manures.

There were a variety of artificial manures introduced into the market, each of which was claimed to be the most effective one.

The enormous success, however, attained by the use of dissolved phosphate or super-phosphate of lime, attributable to the solubility of portions of its phosphoric acid, soon established the character of its superiority, and has elicited the establishment of extensive factories for this class of fertilizers.

The importance of your discovery will be readily understood, from the fact that native phosphate of lime is of rare occurrence, mainly found in Spain and some few other localities, in deposits not large enough to be the object of distant commerce. Found some years ago in the formation of crag and green sandstone of England, its extraction was expensive, and thus the manufacture of the most desirable fertilizer, the super-phosphate of lime, was wanting a source of abundant supply of the main material.

This substance, in future and for a long time to come, will be supplied to the trade to the extent of its demands, without other limits but the labor on the island and the shipping facilities.

Before closing this report, I have to insist on this most important fact, that the phosphate found on the Island of Navassa is a mineral and not a guano, although known since its introduction into this market as Navassa Guano.

From their nature, the deposits of guano are limited, and their rapid exhaustion is already felt by the consumer, but the large development of phosphate of lime—a mineral substance—found on the Island of Navassa, gives the assurance of a permanent and rich yield. As a fertilizer, the action of the ammoniacal guano is mainly due, besides to its contents of phosphates, to the proportion, or the elements it contains for the formation of ammonia. The sources for this agent are numerous, and may be supplied to the wants of agriculture by many varieties of manure, blood, flesh, fish, etc., but the case is not ​the same with phosphoric acid, and from this fact, your property, the Island of Navassa, acquires a value that can hardly be exaggerated, and the working of it on the largest possible scale, will be the source of considerable and most legitimate profits.

G. A. LIEBIG.

P. S.—Some varieties of the native phosphate of lime resist with great force the dissolving action of Sulphuric acid, thereby impeding the process of manufacture of super-phosphate of lime. I have made several experiments to that effect with the Navassa-phosphate, and found that it offers no difficulty in successfully converting it into super-phosphate—samples of which contained from 10 to 15.5 per cent. of soluble phosphoric acid.

G. A. LIEBIG.