The Little Belt Mountains lie to the north, and the Crazy Woman Mountains to the southeast, though at a greater distance. The Tertiary beds found here consist for the most part of homogeneous cream-colored clays so hard as to be with difficulty cut with a knife. The beds are horizontal and rest unconformably upon the upturned yellow and red slates below. The clays of which they are formed resemble closely those found in the Miocene beds at Scott's Bluffs near the North Platte River in Wyoming. The deposits at Camp Baker have been extensively denuded and nowhere reach any very great thickness. At a point about three miles southeast of the Post, some bluffs were noticed where the Miocene beds attained a thickness of 200 feet, and these were capped by fifty feet of Pliocene clays, both beds containing characteristic fossils. In the underlying Miocene beds were found a species of Rhinoceros, several species of Oreodon Leidy and Eporeodon Marsh, a canine tooth apparently of Elotherium Pomel, and remains of Turtles. In the Pliocene beds the principal fossils were a species apparently of Merychyus Leidy, remains of an equine smaller than the modern horse, and Pliocene Turtles. These fossils have not yet been carefully studied, and for this reason their relations to the remains found in the other lake basins of similar age cannot here be stated. We saw the first exposures of these beds a few miles west of the Sulphur Springs, just after crossing a rather high ridge of trachyte through which Deep Creek flows in a narrow and picturesque cañon. This point is about six miles southeast of Camp Baker. From here the lake bed was traced continuously along Deep Creek for a distance of fifteen miles, extending quite up to the mountains on the eastern side at least. Beds of the same character, containing similar fossils, were found on White Tailed Deer Creek, a branch of Deep Creek, about seven miles to the north of Camp Baker, as well as on Camas Creek to the southwest of the Post. Traces of this deposit, containing what appear to be remains of Rhinoceros, were also found two miles or more south of Moss Agate Springs, and at a considerable elevation above the creek bed. With more time than we had at command they could no doubt have been traced much farther, although in many places the beds have been washed out, or have been covered by the later local drift. These Tertiary beds were all laid down after the elevation of the mountains and the igneous eruptions. They are, as has been said, perfectly horizontal, and are often seen covering over ridges of trachyte. The line of separation between the Miocene and Pliocene beds is in some places well marked. It consists of about six feet of hard sands, interstratified with layers of very small water-worn pebbles soldered together into a hard mass, but easily picked out with a knife. Each of these layers is about six inches in thickness. Immediately above these strata the Pliocene fossils were found. In several places fragments of trachyte were noticed in the Pliocene beds. Near Camp Baker are a series of upturned ridges of Potsdam sandstones and limestones at a level very little above that of the Tertiary beds, and doubtless in this region the lake was divided into many arms, which bent around, and extended among, these ridges. It is known that in the neighborhood of Fort Shaw, and near Helena, Pliocene deposits exist, and at Fort Ellis and in the valley of the Yellowstone we saw, but were unable to examine, gray sands and marls, which Dr. Hayden refers to the same age. No Miocene beds, however, have been identified at any of these localities. It seems probable that in Pliocene time at least, the Baker Lake may have extended north to the Missouri River, and perhaps up that stream to the Three Forks, thus connecting with the lake which existed near Fort Ellis. Indeed it would seem that we just touched upon the southern edge of this basin, which may have extended far to the north and west. An interesting point in connection with these deposits, is the fact that they are at a much greater elevation than any other beds of the same age now known on the continent. The elevation of the White River and Colorado beds is about 3,000 feet, and that of the Oregon basin somewhat less, while that of the deposits near Camp Baker is over 5,000 feet. In reference to the relations which this lake basin bears to the Oregon basin and to the White River deposits, nothing can be certainly known without a careful exploration of the whole region and a thorough study of its vertebrate remains. It is by no means impossible that the Baker Lake may have flowed into that at White River by some old river channel, but so little is known of the intervening country that no definite opinion can be pronounced on the subject. ART. XV.-Communications from the Laboratory of Williams College. No. IV.-On the Product of the action of Potassium on Ethyl Succinate; by IRA REMSEN. IN a notice published a short time ago in this Journal,* I described a few preliminary experiments, undertaken with the object of discovering the structure of a peculiar substance which is produced when potassium is allowed to act upon ethyl succinate. Since the time of the first publication, I have been engaged in prosecuting this investigation, the results of which are herewith communicated. The communication is hastened by the fact that quite recently a similar investigation has been undertaken in the laboratory of Wislicenus, and in the publication of the experiments no reference is made to my work. 1. Preparation and Properties. The substance under consideration was first obtained by v. Fehling in the course of an exhaustive examination of the compounds of succinic acid. I give his description of the method of obtaining the substance: "If ethyl succinate, which has been thoroughly dried by means of calcic chloride, is brought in contact with potassium or sodium, the metal becomes oxidized, and the ether is decomposed. At the ordinary temperature the decomposition takes place more readily with potassium than with sodium. The action begins instantaneously; an inflammable gas is evolved which conducts itself. like hydrogen. By gently heating the action is hastened; the mass becomes heated spontaneously, and care must hence be taken not to heat higher than 30-40° at first. In connection with the reaction a peculiar penetrating odor is perceived. If the action is too violent, the mass may easily be thrown out of the vessel in which it is contained.' "If sufficient potassium has been added the mass becomes thick and viscid, and the color of the mass is brown. This color appears to arise from secondary decomposition-products." -"If water is now added to the mass, and it be heated rapidly to boiling, a clear, yellow liquid is obtained, upon which an oily, yellowish layer floats; but it seems to be important not to heat for too long a time. The liquid congeals on cooling, forming a soft, pasty mass. By means of a filter the liquid is separated from a yellow crystalline mass, and the residue washed out with water."-"The yellowish residue upon the filter is purified by repeated recrystallizations from alcohol. * Vol. ix, p. 120. + Berliner Berichte, viii, Jahrgang, 1039. Annalen der Ch. Pharm., xlix, 192. The crystalline mass is now white with a slight tinge of yellow, possessing a beautiful satin-luster, and is very voluminous.' The analyses made agreed closely with each other and led to the formula C,H,O,. 8 Alcohol dis "The compound does not dissolve in water. solves it readily, particularly with the aid of heat; cold ether dissolves it in every proportion. By heating with alkalies this product is decomposed, alcohol is given off which can easily be recognized by the odor; and a yellow solution is obtained, similar to that which was obtained at first by treating with water the mass which was produced by the action of potassium upon the ether. This solution contains potassic succinate." "The crystalline body fuses at 133° and sublimes completely at 206°. With ammonia this product forms a bright yellow body crystallizing in needles." Since the time of the publication of the investigation of v. Fehling, this substance does not appear to have been reëxamined. Only Geuther has indulged in some speculations in regard to its structure, though his speculations are not based upon new experiments. He proposed to double the formula of v. Fehling making it C,,H,O,, and then suggested that the compound was either disuccinic ether or diethyldisuccinic acid. In view of the peculiar method of its formation, it seemed desirable to learn something more definite in regard to the chemical conduct of the body, and accordingly I prepared a considerable quantity of it and subjected it to examination. The statements of v. Fehling in regard to its preparation were found to be in the main correct. It is not a simple matter to tell when the reaction between the metal and the ether is at an end, as the mass becomes very thick, even while warm, and, the metal becoming covered with a layer of the fully decomposed mass is kept from further action. It is very important too, not to have an excess of the metal, for, as we shall see, the new subtance forms with potassic hydroxide, a compound which is easily soluble in water, and is also easily decomposed by the hydroxide, if the temperature is raised. I found it sufficient to recrystallize the product but once from alcohol, obtaining it thus almost pure, either in the form of lamine with a strong luster, or of needles of considerable length. The alcoholic solution exhibits the property of fluorescence to a marked degree, but I have noticed that this property grows less marked the purer the compound becomes. The fusing point of the compound is given at 133° by v. Fehling, whereas I found it to be at 128°. * Zeitschrift für Chemie, 1866, 5. 2. Metallic Compounds. When sodium-amalgam is allowed to act upon the alcoholic solution of the compound, there is produced a voluminous red precipitate, which is very easily soluble in water. From the aqueous solution, chlorhydric acid precipitates a white substance which is insoluble in water and difficultly soluble in alcohol. This substance proved to be the original compound. The same red precipitate, is produced when alcoholic solutions of the compound and potassic hydroxide are brought together, and a similar precipitate when sodic hydroxide is used instead of potassic hydroxide. The latter precipitate was first re pared for examination. Sodium-Compound, C12H,,Na2O, +4H2O. 12 This compound was prepared by bringing together alcoholic solutions of the original body and sodic hydroxide. It is thrown down immediately, as a beautiful red precipitate. This precipitate consists of microscopic needles. It was filtered off and washed out with alcohol. In drying, the color changed from red to yellow, but it appears as though this change of color is not accompanied by a chemical change. The analyses gave the following results: I. 0-201 grams of the substance gave 0.08 grams Na2SO4= 0.0259 grams Na. II. 0-1202 grams of the substance gave 0.048 grams Na,SO4= 0.0155472 grams Na. 14 According to this, the substance has the formula C12H1Na2O +4H,O. It is very easily soluble in water, and the body, С,,,,,, is precipitated from this solution on the addition of an acid. By boiling with a little sodic hydroxide succinic acid is formed. 12 16 61 The corresponding potassium compound is mentioned by Wislicenus (loc. cit.) Another potassium compound of the formula C,,H,,KO, is also mentioned, the existence of which speaks clearly for the formula C,,H,,O for the original substance, instead of the simple formula C ̧¤ ̧ ̧. 2 16 6 6 8 If an alcoholic solution of the substance C,,H,,O, is added to baryta water, a beautiful rose-colored precipitate is pro |