favorably disposed for the etching process. The result of this series of experiments seemed to throw some doubt upon the "elevated" character of the acicular web of crystals; at least as much doubt as may arise from the difficulty of judging the question from the shadows. The former conclusion was reached by a comparison of the shadows with those of a web of crystals of sublimed caffeine which were known to be in relief. If in intaglio, their depression is too slight to be able to form a judg ment by rubbing the etching with vermilion powder. But as the stars are known to be depressions, it may be that the scattered needles are of the same character.

In some examples, two rays of a star-shaped crystal were seen giving the form of a V, which in other cases was transformed into a triangle by an additional needle happening to lie at its base. The A-shaped crystals described upon a former page may be formed in this manner, although they were not so determined.

It results that the window glass examined contains crystals already formed, of which some are more soluble in hydrofluoric acid than their matrix, and perhaps others less soluble in the same reagent.

All of the specimens of glass submitted to the action of hydrofluoric acid yielded crystalline forms. Those of the window glass are similar in appearance to the crystals obtained by Pelouze by the slow cooling of the same kind of glass after it had been maintained for several hours at incipient fusion. Since in the experiments of this chemist no alteration of weight was observed and the normal character of the glass was restored by simply melting, it is probable that the crystals are of the same nature in both instances. It would appear from some of my observations as if the crystals first formed during the refrigera tion of the glass, were subsequently broken by the operations of pressing, rolling &c., to which the material had been subjected. Doubtless additional interesting phenomena might be observed by a more extended study of different varieties of glass under different conditions by the use of this method.

An analogous action of certain solvents upon other supposed amorphous bodies, as the resins, &c. may demonstrate a crystalline character in them.

From a more extended study of this interesting subject, results the most important respecting the true nature of glass may be expected.

The effect of annealing may here find its true explanation.

If we were able to produce at will an interlacement of long fibrous transparent crystals, a glass of superior flexibility and strength might be obtained. It would also be interesting to ascertain what kind of crystals of different substances might be introduced into glass without destroying its valuable properties.

If such, having the crystalline character of mica or asbestus, could be added a valuable product might result.

Leydolt observed in a slag (see his No. 7) cubic crystals of nearly the same color as the glass and visible to the eye. If we could ascertain the nature of the glass crystals as well as that of the matrix (which may also be crystalline) possibly we might, by the laws of isomorphism, be able to color the crystals at will, thus producing new and beautiful effects in articles of glass-ware. In this connection Leblanc's observation of protoxyd of iron in the transparent portion and but traces of this base in the crystalline part of a specimen of glass, may be noted.

The detection of the crystalline nature of glass demonstrates that we are as yet unacquainted with the true character of this complex substance; but at the same time it indicates the path to be pursued for acquiring this desirable knowledge.

ART. V.-Contributions from the Sheffield Laboratory of Yale College. No. IX.-On the assimilation of complex nitrogenous bodies by Vegetation; by S. W. JOHNSON.

DURING the summer of 1861 the writer undertook a series of observations on the nutrition of plants, which, though a failure as regards the principal object of the investigation, led to some interesting results. Besides various inorganic matters, the nitrogenous compounds occurring in urine which may be directly applied to crops as fertilizers, viz: urea, guanine, uric acid and hippuric acid, were intended to be made the subjects of experi

ment.

Washed and ignited flower-pots (of clay, unglazed) were employed to contain, for each trial, a soil consisting of 700 grms. of ignited and washed granitic sand mixed with 0-25 grm. sulphate of lime, 2 grm. ashes of hay prepared in muffle and 2.75 grm. bone-ashes. This soil was placed upon 100 grms. of clean gravel to serve as drainage.

In each of several pots containing the above soil was deposited July 6th, a weighed kernel of maize. The pots were watered with equal quantities of distilled water containing a scarcely appreciable trace of ammonia. But four seeds germinated in a healthy manner, the plants developed slowly and alike until July 28th, when the addition of nitrogenous matters was begun. To No. 1, no solid addition was made.

To No. 2, was added July 28, 0·420 grm. uric acid.

To No. 3, was added 1.790 grm. hippuric acid, at four different times, viz: July 28, 0-358 grm., Aug. 26th, 0.358 grm., Sept. 16th, 0.716 grm., Oct. 3d, 0.358 grm.

To No. 4, was added 0-4110 grms. hydrochlorate of guanine,

viz: July 28th, 0·0822 grm., Aug. 26th, 0·0822 grm., Sept. 16th, 0 1644 grm., Oct. 3d, 0·0822 grm.

The nitrogenous additions contained in each case, 140 grm. of nitrogen, and were strown, as fine powder, over the surface of the soil.

It not being practicable to attend to the germination of other seeds, urea was not experimented with. This deficiency was of less account, since Cameron's paper on the direct nutritive effect of urea, read before the British Association in 1857, had demonstrated that this substance supplies the plant with nitrogen without previous decomposition in the soil and has a fertilizing effect equal to salts of ammonia.'

The plants continued to grow or to remain healthy, (the lower leaves withering more or less,) until they were removed from the soil Nov. 8th.

The plants exhibited striking differences in their development. No. 1, (no added nitrogen) produced in all seven slender leaves and attained a height of seven inches. At the close of the experiment, only the two newest leaves were perfectly fresh, the next was withered and dead throughout one-third of its length. The newer portions of this plant grew chiefly at the expense of the older parts. No sign of floral organs appeared.

No. 2, fed with uric acid, was the best developed plant of the At the conclusion of the experiment it bore ten vigorous leaves, six of which were fresh and two but partly withered. It was 14 inches high and carried two rudimentary ears (pistillate flowers), from the upper one of which hung tassels six inches long.

No. 3, supplied with hippuric acid, bore eight leaves, four of which were withered, and two rudimentary ears, one of which was tasseled. Height 12 inches.

No. 4, with hydrochlorate of guanine, had six leaves, only one withered, and two ears, one of which was tasseled. Height 12 inches.

These experiments, together with a large number of others simultaneously undertaken, failed to give satisfactory results from the unfavorable situation of the only apartment at disposition for conducting them in. The light was good but for a small part of the day, and very unequally distributed at that. For this reason, chiefly, most of the plants made but imperfect growth and therefore the laborious analyses which would have properly supplemented the observations on growth were not attempted.

This result has been recently confirmed by Hampe of Göttingen who has made maize to grow as a water plant with its roots in a dilute solution containing sulphate of magnesia, chlorid of calcium, phosphate of potash, sesquichlorid of iron and urea. Hampe found in the well developed plants-stems and leaves as well as roots-evident quantities of urea.

In the case of the four experiments under notice, the weight of the crops (dried at 212° F.), exclusive of the fine rootlets that could not be removed from the soil, was ascertained with the subjoined results.

We thus have proof that all the substances employed contributed nitrogen to the growing plant. This is conclusively shown by the fact that the development of pistillate organs, which are especially rich in nitrogen, occurred in the three plants fed with nitrogenous compounds, but was totally wanting in the other. The relation of matter new-organized by growth to that derived from the seed is strikingly seen from a comparison of the ratios of the weight of the seed to the increase of organized matter, the former being taken as unity.

The ratio is approximatively

is

The relative gain by growth, that of No. 1, assumed as unity,

for No. 1,

1

56

26

26

No examination was made of the soil to ascertain whether the uric acid, &c., had undergone decomposition with formation of ammonia before entering the plant. If urea escapes decomposition, as Cameron and Hampe have shown is true, for the most part, it is not to be anticipated that the more stable bodies employed in these trials should suffer such alteration.

It will be noticed that the gain of dry matter during growth was identical in case of the plants fed with guanine and hippuric acid, and this quantity was again, quite nearly half that mani

fested by the plant which was supplied with uric acid. Whether this is more than accidental is worthy of study.

From these experiments the writer concludes that the amids resulting from the disorganization of protein compounds, as well as ammonia salts and nitrates, are capable of direct passage into the plant, and there serve for the reorganization of albumen, &c. Cameron, in the investigation alluded to, remarked that his results demonstrate that it is not necessary that urea should decompose into carbonate of ammonia in order to become available to vegetation, and the above facts warrant the generalization that all the amids existing in the urine of animals are ready for assimilation, without any further resolution by decay. So far as they are directly concerned, then, any "fermenting" of manures of which they are ingredients is useless.

Oct. 1865.

ART. VI.-Results of observations on the Drift Phenomena of Labrador, and the Atlantic coast southward; by A. S. PACKARD, Jr., M.D.

THE whole surface of Labrador has passed through a denudation of great extent by continental glaciers. In the southern part of the peninsula, bordering on the gulf of the St. Lawrence, the glaciers evidently moved southward down the slope from the water-shed in the interior. On the eastern or Atlantic coast, at both sides of the mouth of Hamilton Inlet, which is forty miles wide, there are glacial lunoid furrows, like those observed in Maine by Dr. DeLaski, which tend to prove by their direction that a glacier forty or fifty miles in breadth filled this great fiord, and moved in an easterly direction from the water-shed in the interior, thence debouching into the sea.

Owing to the powerful disrupting agency of the frost and ice, the rounded and denuded rocks of Labrador have as yet revealed but few glacial striæ. The distribution of the boulders is restricted to the higher levels of the plateau. To find them in any abundance, it is necessary to ascend 500 to 800 feet above the sea, at which point they occur in profusion. Below this point they have been rolled, rounded, and rearranged into ancient sea beaches. But on the smooth polished quartzites and syenites, the former of which are levelled into broad plains grooved and furrowed and afterward polished almost like glass, with shallow depressions, being glacial troughs filled with water and forming countless pools, and on the rounded syenitic hills which assume dome-like or high conical sugar-loaf forms, we see everywhere in Labrador, below a level of 2000 feet, the traces of ancient glacier action exhibited on a vast scale.