Water was added to the dried powdered root in quantity to make the moisture of the material 77.3 per cent. From this mixture 67.9 per cent. of juice, specific gravity 1.086, was obtained, which gave, calculated to the dry root

Sucrose
Glucose

Per cent.

17.21

1.31

The press-cake from the foregoing operation was exhausted three times in succession with water, each time an amount being taken equal to ten times the weight of root taken; from these combined washings the following results calculated to the dry root were obtained:

ANALYSES OF MARLS, SOILS, CLAYS, ETC.

Frequent applications are made to the department for analyses of marls, soils, clays, peat, and similar substances, and referred to this division, and in many cases the analyses have been made, the results of some of which are given in the following pages.

It is obviously impossible to comply with all the demands made for such work, and in view of the purely local, if not personal, character of the work, it hardly seems desirable that the limited force in the labora

tory should be employed in such analyses. To be of any value practically, the analysis must be thoroughly performed, and few are aware of the time required and labor involved in making a complete analysis, and, as will be seen, it not infrequently happens that specimens of marl, &c., submitted for examination are quite worthless, and the time given to their analysis practically lost. The same remark applies to ores, minerals, and mineral waters, of which there are very many specimens received from all parts of the country, generally from those without much knowledge concerning the general character of the specimens sent, which specimens almost always prove worthless.

SOIL FROM SMALL MANGROVE ISLAND, OFF THE FLORIDA COAST.

Received from Prof. S. F. Baird.

This was a peaty mixture, containing considerable undecomposed woody matter. Owing to the small amount received a partial examination only was made.

The presence of so large a quantity of phosphate of lime in the above sample appears to indicate an extensive deposit of this mineral in the immediate vicinity where the sample was obtained.

UNPRODUCTIVE SOIL.

From L. Allen, Oak Hill, Volusia County, Florida.

The analysis of this soil shows that its barrenness is very likely due to a lack of constituents suitable for plant nourishment, and not to the presence of any injurious substance.

Received from William W. Wood, Jutland, near Point Lookout, Saint Mary's County,

Maryland.

A water extract from this soil had an acid reaction and gave decided reactions for sulphates and chlorides of iron, lime, magnesia, potash. and soda, together with a little organic matter. This water extract amounted to 11.84 per cent. of the original soil, and consisted of—

The large amount of soluble iron salts is remarkable. They are injurious to crops except when present in very small quantities. On the other hand, the considerable amount of potash is a favorable indication. It would be best to allow the air to have free access to this soil, so that the soluble salts of iron may become insoluble and harmless.

*Includes 1. 003 per cent. of nitrogen, equivalent to 1. 224 per cent. of ammonia (NH3). Includes 13. 74 per cent. of phosphoric acid (P:O), equivalent to 30.00 per cent. of phosphate of lime, (Ca3(PO4)2); also some carbonate and a trace of potash.

LEAF MOLD.

Received from J. F. Armour, Manistee, Mich.

Examined for heating purposes, gave as follows:
The sample was first dried and pulverized.

When dried the heating value of this sample would be approximately the same as that of dry peat.

Its fertilizing value is represented by 2.10 per cent. of nitrogen, equivalent to 2.55 per cent. of potential ammonia; a trace of phosphoric acid was present, but no potash. As an addition to a compost heap it would probably prove valuable.

COMMERCIAL FERTILIZERS.

As in former years, a considerable number of commercial fertilizers has been analyzed and reports made upon their value. Nearly all these fertilizers have had a local reputation, good or bad, in the sections from which they came, but it seems hardly advisable to print their analyses here, because they are of interest to only a very few persons. At the same time it is very important that the farmer, who is obliged to buy fertilizers, should thoroughly understand what constituents give value, and what others merely add weight. It has been found as the result of experience that the following substances are necessary to the plant that it inay grow and mature properly.

1.-NITROGEN.

It is not proven, and it seems very doubtful, whether any part of the nitrogen absorbed and assimilated by plants is derived directly from the free nitrogen in the air. On the other hand, abundant evidence exists that ammonia, or any substance which can furnish it, and nitrates have direct and positive effects for good on growing plants. No plant has ever been examined which did not contain a greater or lesser proportion of nitrogenous constituents at all stages of its development, and in all its essential organs. The amounts of nitrogenous constituents vary greatly in different families of plants, in different members of the same family, and in each individual at different stages in its growth. Hence an intelligent discrimination should be made in applying nitrogenous fertilizers, in order that the necessities of the growing plant may be satisfied without excessive waste and expense for the fertilizer. Nitrogen may be furnished to the plant in three ways, viz:

a. As actual ammonia.

Free ammonia gas (NHI) is liberated from many substances when putrefying, and carbonate of ammonium ((NH4)2CO3) always results from the decomposition of urine, stable manure, &. In these forms ammonia has the characteristic pungent odor of "hartshorn," so well known. Besides these familiar sources, the distillates from gas-works and those obtained in charring bones, &c., for the manufacture of animal charcoal ("bone black "), furnish large quantities of ammonia, which is made into a white crystalline sulphate ((NH4)2SO4), and thus furnished

to the trade. This sulphate of ammonium varies in color from pure white to nearly black, according to the quantity of tarry impurities present. It has no odor when pure, and only a slight tarry odor when quite impure. A pure sample yields upon analysis 25.75 per cent. of ammonia gas (NII); commercial samples are valuable just in proportion to the amount of ammonia they yield upon analysis.

The following analysis represents the composition of a very good com mercial sample:

Probably there is no better way of applying ammonia to the soil than in the form of ammonium sulphate.

Nitrogen may also be furnished to crops as-

b. Potential ammonia.

By the term "potential ammonia" we understand that the substance spoken of contains a certain quantity of nitrogen, which, under favorable conditions, may have a food value equivalent to a certain amount of ammonia. The substances which contain nitrogen that may furnish this potential ammonia are various both in chemical composition and physical form. Some of the principal kinds will be enumerated.

1.-Excrements.

Ordinary barn-yard manure, if properly housed and applied, is one of the most valuable of fertilizers. It is very complex in its chemical composition, but contains a very considerable amount of nitrogen in such a form as to readily furnish nitrogen to the growing plant. The urine of animals is also rich in valuable nitrogenous matters, and when properly applied will well repay the cost for storage and handling. Besides these common forms there are a number of localities in our Southern States where bat excrements are found, usually in caves. These excrements are very rich in potential ammonia, and have proven very valuable fertilizers. In the annual report of this department for 1876, pp. 49 to 52, will be found several analyses of bat guano. A sample this year received from M. W. Townsend, Austin, Tex., contained the following valuable constituents: Total nitrogen, 11.088 per cent., equivalent to 13 464 per cent. potential ammonia; Potassium oxide (KO), .91 per cent.; and Insoluble Phosphoric acid (P2O5), 6.18 per cent.

Guano is another excrementitious substance which has been abundantly used and with excellent results. It is rich in nitrogen in a readily available form. It should only be bought upon analysis of some reliable chemist, as many inferior imitations are sold by unprincipled parties.