in the manner described above. The yield is 30 per cent of that required by

P6N6O12H12+4H2O=P1N1OH® +2NH,H2PO1.

After purifying, it was converted into the silver salt, which gave:

Comparison of the crystals of free acid and of the acid and neutral ammonium salts, acid potassium salt, neutral sodium salt, and silver salt with similar preparations made from tetraphosphonitrilic chloride showed that they were identical.

The decomposition products were not further studied.

AMIDOHEXIMIDOHEPTAPHOSPHORIC ACID, P7N7015H16.

The saponification of heptaphosphonitrilic chloride is effected in the usual manner with sodium hydroxide. As before pointed out, this acid does not give the lactam, heptametaphosphimic acid, even in acid solution, the silver salt having the composition of a salt of the openchain acid.

Sodium salt. The properties of this salt are similar to those of sodium penta- and hexametaphosphimate. Dried in vacuo and at 100°, it gave:

Silver salt, P,N,O15H,Ag7.-To obtain a salt of normal composition, 1 gram sodium salt is dissolved in 50 cubic centimeters water, enough nitric acid is added to form a salt with 6.85 atoms of sodium, and precipitated by 50 cubic centimeters one-fifth normal silver nitrate. More sodium or silver nitrate gives a salt richer in silver. The salt forms a white semigelatinous precipitate, which dries in vacuo to translucent brittle lumps, which were pulverized, dried again in vacuo and then carefully to constant weight at 1000.

These figures show beyond question that the acid has the open form P2NO 15H16.

The decomposition of the sodium salt by acetic acid gives rise to a considerable amount of tetrametaphosphimic acid, characterized by its crystalline form and that of its salts.

HIGHER ACIDS.

Of the higher acids of the series but little can be said. The oil remaining over from preparation of chloronitrides, and which has a mean molecular weight nearly corresponding to PNC, on saponification gives a mixture of sodium salts which are precipitated by alcohol in a decidedly viscous form, and which are decomposed by acids, giving tetrametaphosphimic, diimidotriphosphoric, and triimidotetraphosphoric acids. They were not further investigated.

AMIDES OF METAPHOSPHIMIC ACIDS.

Amides of P3N3O6H6.-Strong ammonia gas acts slowly on a solution of PNC in absolute ether, the product being at first ammonium

chloride and the chloramide, P ̧Ñ3

CL
(NH2)2

This remains in solution

and is gradually attacked further, but is the only product of the reac tion which is soluble in ether; by further action of ammonia the chlorine is further substituted, but never completely, and the reaction product is thrown down, mixed with ammonium chloride. On washing this with alcohol, dissolving in water, and treating with enough silver nitrate to precipitate the chlorine, a solution is obtained which, by fractional precipitation with silver nitrate, gave the silver salt of an amide with the ratio P: N: Ag = 3: 6.27 : 2.01. An ethereal soluCL

salt of the diamide of trimetaphosphimic acid, from which the chlorine may be removed by neutralizing with nitric acid and adding the calculated amount of silver nitrate. From the filtrate an amorphous silver salt may be precipitated which gave the ratio P : N: Ag=3:4.88: 3.51. If P3N3C16, PN,Cls, or PN,Clio in ethereal solution is shaken with ammonia of sp. gr. 90, a strong reaction occurs at first, whereby a portion of the chlorine is replaced. On shaking two or three hours, the remainder is removed. The excess of ammonia was removed from the aqueous solution by blowing air through and the chlorine precipitated by the theoretical amount of silver nitrate. The ammonium salts of the amides thus obtained were thrown down by alcohol as sirups which can not be hardened under absolute alcohol. If these solutions are precipitated by silver nitrate, after adding a little ammonia, amorphous white precipitates of the amido silver salts are obtained, which do not show a constant composition. Analysis gave the following atomic ratios:

From these figures it appears that the amides are of very varying composition. As they are amorphous and very unstable, it is unlikely that any definite bodies can be obtained in this way. The silver salts are turned yellow by potassium hydroxide, a portion of the amide going into solution and a salt with a higher proportion of silver being formed.

ON A HYDROMICA FROM NEW JERSEY.

By F. W. CLARKE and N. H. DARTON.

While studying the Juratrias formation in New Jersey, one of us (Darton) found in an old "trap" quarry at Rocky Hill a hydromica, which occurred under such novel conditions that it appeared to be worthy of investigation. It is found in veins of calcite, mainly as a thin coating, and adjacent to the diabase of the vein walls. The latter consist of more or less decomposed rock, of which the principal product is a soft, dark-green chloritic material. In portions of the vein the mica extends down the cleavage planes into the masses of calcite. A considerable amount of the calcite was thrown out during the quarrying operations, but only a portion of it is covered with the mica. This portion presents the appearance of having been coated with bronze paint. The mica occurs in minute flakes thinly matted together. Its color is golden bronze, although some portions are slightly greenish. The mineral is soft, and thinly foliated. Under the microscope it exhibits no definite crystalline form; and its optical properties, although not distinctive, suggest biotite. It appears to be biaxial, but with a very small axial angle, and it is pleochroic. When heated, it does not exfoliate. It fuses before the blowpipe, at a moderately high temperature, to a dark-colored bead. The specific gravity was not determined. It is readily decomposable by hydrochloric acid. The analysis, by Mr. George Steiger, of material not free from calcite is subjoined. In the second column of figures the reduced analysis is given, titanic oxide and calcite being thrown out, soda recalculated to terms of potash, and the whole adjusted to 100 per cent.

This gives, as an orthosilicate, the formula

(KH)(MgFe)24(AlFe)51(S1O4)+7. 28H2O.

It is evident, from these data, that the mica is one which has been largely, but not wholly, altered to a vermiculite; the latter term indicating a mica in which potassium has been replaced by hydrogen, and which has taken up water of crystallization. So far as the analysis. goes, the condition of the water is uncertain; for it was determined in two fractions only, at and above 100°, whereas more fractions are needed for accurate diagnosis. Some crystalline water may be retained far above 100°, so that the loss above that temperature includes part of this fraction plus all the water of constitution. Apart from this uncertainty the ratios reduce easily in terms of the mica theory to the following molecular mixture:

3 Al-SiO, Al +6R" -SiO,= R" + 5 R'"'—SiO1 = RH 3 aq.

Calculating with the atomic ratios Al: Fe": :2: 3, and Fe": Mg: :3:7, we have the following comparison between analysis and theory:

In short, the mica consists of muscovitic and phlogopitic molecules in the ratio of 9: 5.

9 R3 (SiO4)3R'3,

5 R'" (SiO4)3R“зHз, 3 aq.

The mineral is evidently an unusual mica, differing widely from any other hitherto described. Its very high proportion of ferric oxide is its chief characteristic, and suggests a ferric muscovite as one of the antecedent, unaltered molecules. Such a muscovite is theoretically conceivable, but is not actually known.