classes which go to smooth rolls for reduction to flour or in part to a run of stones. The resulting flours are graded according to their quality by various bolts and the bye products of all these processes are collected as shorts and the various kinds of tailings, dust and low grade flours all of which appear in the representative samples which have been analyzed.

One of the peculiar advantages of the process is the removal in the first few boltings after the use of the scalping reels of the greater part of the gum of the grain which when passed through smooth rolls with the tailings are easily flattened and separated by appropriate bolting machinery, thus making it possible to produce a flour uncolored by the oily and nitrogenous matters of the gum.

The results which have been obtained in the analyses of the specimens referred to are presented in the accompanying tables.

They show that the soft interior of the grain which is removed in the first breaks is of a starchy nature, the albuminoids and gluten increasing toward the exterior of the grain. The outer portions also contain more oil and ash and consequently more phosphates.

While the gluten is more abundant in the outer portion of the grain and especially in the part adherent to the bran which is removed in the last break there is none at all in the outer coatings themselves, the so called gluten cells of the embryonal membrane containing similar substances to the embryo or gum of which it is a continuation. All of the gluten of the wheat is in the endosperm or floury portion of the berry and can be more completely recovered and carried into the various grades of flour by the roller process at least with Hard Spring Wheats than by other methods of milling.

The shorts removed by the bolting and aspirating machines are, like the bran, rich in albuminoids, oil and ash but not as much so in the two latter constituents.

The graded middlings both uncleaned and cleaned show very regular variations in the various constituents, ash, fat and fibre decreasing from what is known as No. 1 to No. 5 and the albuminoids or gluten being the best in No. 4.

The effect of cleaning is to increase the percentage of gluten while not altering the percentage of nitrogen showing that the material removed by the process is not rich in gluten.

The flour, produced by the reduction of the purified middlings is not as rich in gluten, ash or fibre as the middlings themselves. The cause of this is not quite apparent as the tailings with one exception are not rich in gluten; in fact, in two cases contain none and in a third less than one per cent.

The tailings from the middlings purifiers in a like manner contain no gluten in the No. 1 purifier and gradually increase till those from No. 6 are rich.

The different flours are mixed for the market in the three grades Bakers', Patent and Low Grade. The Patent is of course the highest grade and whitest. It contains however less gluten than the bakers' grade and the least ash, oil and fibre of any. The low grade flour is very rich in nitrogen but extremely poor in gluten, the result of mechanical and chemical causes which have injured the flour in the process of manufacture.

The remaining analyses are of technical interest. Among them are those of the gums extracted at different points in the purification of the tailings. That known as "second gum" seems to be freer from impurities and has been analyzed in detail showing that one-third of the substance is albuminoids, over fifteen per cent oil, and nearly nineteen per cent a sugar-like substance making it of considerable interest.

I shall consider the results more at length in a report to be issued by the Department of Agriculture, Washington, D. C.

ANALYSIS OF A MURAL EFFLORESCENCE. By Prof. CHAS. E. MUNRoe, U. S. Naval Academy, Annapolis, Md.

THE incrustations which so frequently disfigure our finest brick buildings have sometime since received attention from chemists and engineers, but we find marked differences in the statements made as to their composition. Thus, according to Trantwine, 2 Pemberton, and 3Goldsmith they consist largely of magnesium sulphate and it is suggested that they are formed either through

1Jour. Frank. Inst. [3] LXXV, 259,1878. 2Jour. Frank. Inst. [3] LXXVI, 52,1878. Proc. Phil. Acad. Sci. XXVIII, 334,1876. 12

A. A. A. S., VOL. XXXIII.

the action of the sulphuric acid in our city atmospheres on the magnesium salts in the mortar, or through the action of this acid, from the coal used in burning the bricks, on the clay from which the bricks are formed. Watts and 5Gillmore, on the other hand, find the efflorescences to consist principally of sodium carbonate with some sodium or magnesium sulphates.

In 1876 a somewhat costly building was erected here in which considerable elaborateness of design was displayed, but, before six months had passed an efflorescence appeared upon it and to such an extent as to almost completely destroy the artistic effect, and in spite of the many severe storms to which it has been exposed and notwithstanding the fact that it is, as my tests have showed, completely soluble in water, it yet exists in apparently undiminished quantity.

The building was constructed of wood-burned, pressed brick, made from Washington clay, for the outside courses, and these were laid in mortar made with lime from Texas, Pa., and pointed with black mortar. The interior wall was of common brick and the space between was filled with Rosendale or Round Top cement mixed with Texas lime mortar in the proportion of one of cement to two of mortar. During the process of building and after completion the structure was pretty well soaked by rains. The town contains less than 7,000 inhabitants and there are no manufacturing establishments whatever, so that the air is quite pure save for the solids taken up from the salt water of the contiguous bay and river. These efflorescences are rare here and are confined wholly to buildings erected in recent years and usually to those made from pressed bricks.

As has been said, this efflorescence was found to be readily soluble in cold water with the exception of 2.62 per cent of residue, which proved to be particles of brick dust. Leaving this out of account the analysis gave

A STUDY OF THE PHENOMENON OF DELIQUESCENCE.

By Prof. CHAS.

E. MUNROE, U. S. Naval Academy, Annapolis, Md.

IN the Proc. U. S. Naval Institute 9, 332, 1883, I have given the results of an observation on the comparative attractive power of calcium chloride and bleaching powder for moisture when exposed to a moist atmosphere. Having allowed these substances to remain exposed to this atmosphere during a very long period of time after the weights, cited there, were recorded, I was surprised to find that the increase in weight for the Ca Cl2 was greatly in excess of that which Brandes1 found in his experiments on the deliquescence of this substance. As, for the requirements of this experiment, the commercial salt had been used, I determined to repeat the experiment with another specimen of the salt which I had prepared.

The salt was made, according to Fresenius2, by dissolving marble in common HCl diluted with five volumes of water. To this a thin paste of lime was added, with stirring, until it was in excess, and the mixture stood for twenty-four hours. It was then filtered; washed hydrogen sulphide was passed through it to saturation; again allowed to stand over night; and again filtered. It was then strongly acidified with pure concentrated HCl; concentrated in a porcelain dish and again filtered; then it was evaporated to dryness, a little HCl being added towards the close of the process. The residue was finally exposed to a tolerably strong heat, on the sand bath, until it was changed to a white, porous, opaque mass. This residue, when cold, was free from alkaline reaction and gave a slight reaction for water by the closed tube test. When dissolved in water and acidified it gave a faint effervescence due to carbon dioxide. Besides these substances only calcium and chlorine were found to be present. The quantitative determinations for chlorine and calcium yielded the following results.

Assuming the excess of Ca present, over that necessary to form Ca Cl2 with the Cl found to be combined with carbon dioxide, and

'Schweiges Jour., 51, 433.

2 Quan. Anal. (Am. bd.,) 127, 1882.

taking the water by difference, we may regard the salt as having the following composition

Fresenius states that the salt, made by the method described, has the composition Ca Cl2 (H2 O)2.

The portions of salt used in these experiments were all taken from the same weighing tube and to check any error which might arise from particles of the salt becoming attached to the outside of the tube or cork, the tube was allowed to remain in the balance case for some time after each weighing made for the purpose of analysis, and the change in weight observed. The greatest change observed was a gain of .0003 grams between the weighing out of the second portion for the determination of the chlorine and that for the determination of the calcium. This would make the Ca CO, as calculated a little too small but would not affect the Ca Cl2.

The experiments for deliquescence were made by weighing out a portion of the salt in a small watch glass and placing it on a vessel containing distilled water. The top of the vessel was covered with wire gauze and the watch glasses rested upon a plate of glass placed upon this. The vessel was placed on a plate of glass beside the balance and the whole covered with a low bell glass. For each observation the bell glass was removed twice, and the weighings were made in a different atmosphere from that existing in the bell glass, but all was done as rapidly as possible and the weights were always taken in the same order. The weights of the substances taken were:

The portions taken were weighed out at 1.15 P. м., Mar. 15, and by 4.30 P. M. on the same day they had both become completely liquefied, while the liquid was perfectly transparent. On Mar. 24 a slight cloudiness appeared and persisted, without increasing in quantity or extent, to the end of the experiments. This film appeared as a plane with its edge in the surface of the liquid, and it appeared either normal to or parallel with the line of sight as