4. The methods used by tanners, to test the strength of their liquors and tanning materials.

5. Investigation of the supposed loss of considerable quantities of tannic acid during tanning, by oxidation to gallic acid. 6. A partial analysis of an exhausted tan liquor.

DEPARTMENT OF METALLURGY.

A Report on the Vershire Copper Mine and Ore. Abstract by the author, R. H. Gould.

The first part of this thesis is devoted to a description of the mine and the method adopted for working the ore at Vershire. The second part describes the working of about 500 pounds of the ore at the Institute.

I. The ore mined at Vershire is a sulphide of copper and iron (Chalcopyrite) which occurs associated with a large amount of pyrrhotite and quartz. The method adopted for extracting the copper consists of the following operations. 1. Cobbing the ore to a uniform richness of about 9 per cent.; 2. Roasting the ore in large heaps to expel a portion of the sulphur; 3. Fusing the roasted ore in blast furnaces to obtain a matte containing from 30 to 35 per cent. of copper; 4. Roasting the matte in kilns to expel the remaining sulphur; 5. Fusing the roasted matte in blast furnaces to obtain pig copper containing 95 to 96 per cent. of metallic copper.

II. The working of the ore at the Institute is divided as follows:

1. Preliminary Treatment. The ore was first examined for the various minerals which it might contain. Those found were, chalcopyrite, pyrrhotite, quartz, blende, garnet, feldspar and mica. The first three make up about 95 per cent. of the

ore.

The ore was next crushed to lumps of half inch diameter, and sampled. The ore on analysis gave the following:

iption of the at Vershire

pounds t

opper and

e amount

tracting

Sing the

ing the

using ining

te in

ted

2. Roasting of Ore. The ore was roasted in reverberatory furnaces for four hours, during which it lost over one half of its sulphur.

3. Fusion for Matte. The roasted ore was fused in a blast furnace, puddle cinder and limestone being used for fluxes. The main products were, a matte containing about 25 per cent. of copper, and a perfectly fusible slag of the following composition:

ད

4. Roasting of Matte. The matte was roasted in four charges, of 56 lbs. each, for about six hours.

5. Fusion for Black Copper. The roasted matte was fused in a blast furnace. Revere acid slag and sand being used as fluxes. The main products were:

1. Black Copper very highly charged with iron;

2. Matte containing about 44 per cent. of copper;

3. Slag which was perfectly fusible, and on analysis was found to contain no copper.

DEPARTMENT OF NATURAL HISTORY.

Catalogue of the Alcido in the Museum of the Boston Society of Natural History; with a review and proposed classification of the family. Abstract by the author, W. B. Barrows.

In this paper the family is first located and then briefly defined; its prominent characteristics, as shown in the various specimens in the Museum, being simply enumerated, and the more critical notice of specific and generic differences left for the descriptions of Genera and Species which immediately follow.

The descriptions are all original and are made from actual specimens in the Museum. Twenty-one species are included in the family and twelve of these, representing every Genus, are contained in the Museum. No descriptions of species have been given where actual specimens have not been handled, but each species is assigned its place in such a manner as to make a connected series which seems to best represent the natural relations of the members. One feature of the work is the reduction in the number of Genera usually admitted, only seven being here accepted; while the exclusion of sub-families is a parallel feature. These two points, involving the whole relation of species to species, are somewhat fully, though not exhaustively, discussed in the concluding third of the paper, where the grounds for every step have been carefully considered.

Two plates, containing figures of thirty beaks (both plan and elevation) conclude the paper.

The whole classification differs widely from those most generally in use; but the writer has been largely guided by such facts in the embryology of the group as have been within his reach and ability; and these facts, which have thus far been too generally overlooked, have made many of these changes imperative.

Geology of Eastern Massachusetts. Abstract by the author,
W. O. Crosby.

This essay is prefaced by some remarks on the general structural features of the eastern United States.

Attention is called to the existence, during Paleozoic time, of a great gulf on the western side of the Appalachians, forming part of the interior Continental sea.

In this Paleozoic gulf is found a probable cause for the greater thickness of the Paleozoic sediments in the Pennsylvania region as compared with any other part of the Continental basin.

The general absence of Paleozoic strata from the Atlantic slopes of the Appalachians is noted, and the fact pointed out that the Paleozoic rocks of eastern North America were deposited about the western and northern sides of what is now a long and narrow belt of land stretching from Maine to Georgia. Much evidence is adduced to show that this limited area had a greater extension to the east and south-east in ancient times than now; that there must have been during Paleozoic time, where now lies the basin of the Atlantic thousands of fathoms deep, a great continent, from which were derived the detrital materials forming the Paleozoic sediments of both Europe and America.

It is shown that our Atlantic coast line exhibits two grand deflections or bays, the Gulf of Maine lying between Cape Cod and Nova Scotia and the large nameless deflection of the middle portion of the coast between Cape Cod and Cape Hatteras. The latter, which has been christened the Alleghanian Gulf, is proved to date from the beginning of Mesozoic time and to owe its existence to the great accumulation of sediments forming the Alleghany Mts.

The Gulf of Maine, on the contrary, is shown to be far older, having been, like the Gulf of St. Lawrence, with which it formerly communicated, in existence during the whole of Paleozoic time. Its origin is found in the erosion of an anticlinal of old crystalline rocks.

The age and relations to the Paleozoic sediments on the west and the Metazoic on the east of the rocks forming the long and narrow belt of land, before adverted to, stretching from Maine to Georgia, are discussed at some length, shown to be, with small exceptions, chiefly crystallines, and to probably ante-date in their origin the earliest Primordial.

Coming to the proper subject of the paper, the relations of Massachusetts to this Eozoic belt are defined and the rocks of the State divided into two principal groups: (1) the crystalline, and (2) the uncrystalline.

The crystallines are further divided into the Norian, the Huronian and the Mont Alban. Then follows at considerable length, forming the major part of the essay, an account of the lithology, distribution and probable origin of the various rocks forming each of these formations.

The rocks referred to the Norian are identified with the Norian of other regions, and, although occupying but a small area in the Eastern part of the State, are shown to be of great scientific importance, since they are the oldest rocks in Massachusetts and perhaps in New England, and afford a key to the geology of this whole region.

The stratigraphical relations of the Norian of this vicinity to the rocks of the same and of Laurentian Age in New Brunswick is pointed out.

The rocks of the Huronian Age are divided lithologically and chronologically into several groups, which, stated in their order of sequence, are granite, felsite, diorite, and stratified rocks including limestone. These are minutely described, their lithological and stratigraphical relations pointed out, showing that they are strictly members of one and the same series, and the law governing their distribution indicated.

The derivation of the compact felsite from conglomerate is briefly treated, old views discussed and new ones advanced.

General sections across this formation from north to south are given, showing that there is a repetition of the strata which can be accounted for only by a gigantic fault which must ex