This table shows: That an oxydizing agent, chlorate of potash (12), is not more injurious than a reducing one, sulphite of soda (11), to germination, but after germination it kept down vegetation to one-fourth. That free acids are much more injurious than alkalies, especially hydrochloric acid (3). That the presence of an electric pair did not check germination, but reduced vegetation by one-third. That the presence of free sulphuric acid had no injurious influence upon germination, actually a larger proportion of seeds started than with pure water, whereas with hydrochloric acid only three seeds germinated out of twenty. But sulphuric acid reduced vegetation to one-sixth, hydrochloric to 2.8 per cent. With bicarbonate of potash, precisely the same number germinated as with plain water, and attained precisely the same height. In (9) the HCl acted less energetically than in (3), doubtless because it was rapidly taken up by the zinc. Plants in the sulphite of soda attained the same height as those in plain water. But the number germinating was one-fourth less. A second set of trials was made, in which a number of other substances were experimented upon, and at the same time sulphuric acid was added in much smaller quantity, and sulphite of soda in much larger. Capacity of the vessel as before, 12 oz. No. 1, Plain water. 2, Cane sugar, 30 grains, No. 6, Citric acid, 5 grains. 7, Sulphite of soda, 20 grains, 8, Permanganate of potash, 2 grains. 9, Nitrate of ammonia, 20 grs. The object of this series was to include in the experiments certain organic substances such as the three first on the list, a vegetable acid, and some salts whose influence might be active and characteristic. At the end of thirteen days, during which the weather was very cold (Dec. 10 to Dec. 23), the following was the condition of affairs. Nos. 2 and 4 (cane sugar and glycerine) were as far advanced as the plain water (No. 1), but no further. These substances therefore had not stimulated either germination or early vegetation in the wheat seeds. In 3 (gum solution) fewer seeds germinated than in either of the foregoing, but the most advanced plants were fully one-half higher than any in 1, 2, or 4. Nos. 7 and 9 (sulphite of soda and nitrate of ammonia) were somewhat in advance of those in plain water, but not very much. In 6 (citric acid) a large number germinated, and appeared healthy, but they did not obtain one-fourth the height of those in No. 1, and what was very remarkable, they formed no roots at all. In 5 (sulphuric acid) the plants were more advanced than in the citric acid, and had healthy roots extending down into the liquid. In 8 (permanganate of potash) the condition of affairs most resembled that in the citric acid. In both the seeds had gerininated and produced healthy looking plants an inch in height. But no roots whatever had been formed in either case. Some of the above sets of seeds were allowed to vegetate for a month, and developed curious results. Those plants which grew in the vessels containing solutions of cane sugar, gum, and glycerine respectively, grew as fast and flourished as well as those in plain water, but it could scarcely be said that at the end of the month they presented any superiority. But whilst the roots of the plants in plain water, in gum, and in glycerine, reached to the very bottom of the vessel, becoming four to five inches long, those in the cane sugar did not exceed an inch in length, just dropping below the surface of the water, which had become lowered by spontaneous evaporation, and this although the plants were as high as in the others just mentioned, viz., six to eight inches, and as numerous and healthy in every respect. This would seem to indicate that they received their nutriment in a more concentrated form, if it were not that these plants, though equally large and healthy as those in plain water, exhibited no superiority over them. ART. XXII. Contributions from the Sheffield Laboratory of Yale College.-XIII. On Native Crystallized Terpin; by S.W.JOHNSON. IN October, 1866, the writer received from Wm. M. Gabb, Esq., of the Geological Survey of California, a small quantity of crys tals found in "cavities near the core of a semi-decomposed pine stump that was buried three or four feet below the surface in Shasta Co., California." The crystals were discovered by Mr. Voy of San Francisco. At the request of Mr. Gabb I have examined these crystals, which, in the sample received, were still partly adhering to a fragment of pine, where they were associated with another crystalline substance of a yellowish color and resinous aspect. The crystals were colorless and transparent, the largest individual was three-eighths of an inch long, one-eighth of an inch wide and one-sixteenth of an inch thick. They were of brilliant luster and well terminated at the free ends. From their occurring in buried pine wood and from their general appearance, it 201 was at once suspected they might be identical with crystallized terpin. Their faint resinous taste and odor, not to be distinguished from that of the artificial substance, confirmed this view. To obtain full information regarding the crystallometrical characters of the substance, I applied to my friend, Mr. John M. Blake of New Haven, to make a comparison between the native crystals and those of artificial preparation from the chemical cabinet of the Sheffield Scientific School. Some of the highly interesting results of these investigations are communicated by Mr. Blake in the paper that follows, and leave no doubt of the identity of the two substances, although their crystals are not developed in the same manner, and exhibit other physical differences which, as he states, disappear when both are recrystallized from the same solvent.* After Mr. Blake had finished his examinations, a combustion was made on nearly the whole available substance. The hydrogen determination was lost by the fracture of the CaCl tube, but the estimation of carbon fully confirmed the conclusions previously arrived at. The combustion was effected in a tube partly filled with oxyd of copper and in a stream of oxygen, the substance itself being placed in a tray of platinum. On application of heat it swelled and afterwards vaporized completely, without blackening and without leaving a weighable residue. On the cold parts of the tube silky crystals of anhydrous terpin condensed. This deportment is characteristic of terpin. The amount of substance burned was but 0.0975 grm. The increase in weight of the potash bulbs and tube was 0.225 grm. This gives carbon 62.93 per cent. The calculated quantity is 63.16 per cent. 20 The substance is therefore hydrated terpin or crystallized turpentine camphor C, H,,O,+2aq. Perhaps we should say it is one of the terpins, since, according to Berthelot, the different oils of turpentine, on hydration, yield crystals of different degrees of solubility. The formation of this substance in the buried tree presents no difficulties, since we know on the authority of Dumas, Deville and others, that oil of turpentine in contact with water, combines with the latter in absence of acids or other powerful agents of chemical change. Prof. Brewer, who is familiar with the timber of California, is of the opinion that the wood to which the crystals were attached is that of a pitch pine, Pinus ponderosa. This appears to be the first recorded instance of the occurrence of crystallized terpin, native. November, 1866. * Mr. Blake has measured and figured both the native and artificial crystals and has in reserve some other valuable observations which it is to be hoped he will shortly publish.-8. W. J. ART. XXIII. On the crystallization of natural Hydrated Terpin from California; by JOHN M. BLAKE. SOME crystals, from a buried pitch-pine log, were handed me for examination by Prof. S. W. Johnson, of the Sheffield Scientific School. A comparison of these crystals with terpin of artificial preparation leaves no doubt that the natural substance is hydrated turpentine camphor. The natural and artificial crystals agree closely in their angles, and have the same cleavage. The position and separation of the optical axes is alike in both, and experiment shows that the two substances are supercrystallizable. Certain observations made at first, suggested that the two specimens might not be absolutely identical, but rather isomeric hydrates, such as were supposed by Berthelot to result from isomeric oils, derived from the same or different trees. Thus, hemihedrism constantly occurred on the natural crystals, which has not been observed on the artificial. The proportional development of the planes was strikingly different. The two specimens manifested opposite pyro-electric characters, in so far that the free-growing extremities of the natural crystals were antilogue poles, (developed negative electricity on heating,) while those of the artificial crystals, first examined, were the reverse, or analogue poles. On further investigation, these points of difference disappeared. By recrystallizing from alcohol and other solvents, much variation was produced in the planes. The peculiar development of the natural crystals was not indeed reproduced on the artificial, but the attachment of the latter to the support by the analogue pole, as with the natural crystals, was obtained. On recrystallizing from alcohol, natural terpin lost its hemihedral character, and in case of crystals grown radiating from a support, presented the analogue pole to the solution, like the artificial substance when deposited from the same solvent. Crystals of each, when free-growing in alcoholic solution, had the same development of the planes, and with each there was the same perceptible difference in the proportions of the planes at the two ends of a crystal, by which the poles could be distinguished; but no corresponding difference could be detected in the angles of these terminal planes. ART. XXIV. On the Objects and Method of Mineralogy; by T. STERRY HUNT, F.R.S. (Read before the American Academy of Sciences, Jan. 8, 1867). MINERALOGY, as popularly understood, holds an anomalous position among the natural sciences, and is by many regarded as having no claims to be regarded as a distinct science, but as constituting a branch of chemistry. This secondary place is disputed by some mineralogists, who have endeavored to base a natural-history classification upon such characters as the crystalline form, hardness, and specific gravity of minerals. In systems of this kind, however, like those of Mohs and his followers, only such species as occur ready formed in nature are compre hended, and the great number of artificial species, often closely related to native minerals, are excluded. It may moreover be said in objection to these naturalists, that, in its wider sense, the chemical history of bodies takes into consideration all those characters upon which the so-called natural systems of classification are based. In order to understand clearly the question before us, we must first consider what are the real objects, and what the provinces, respectively, of mineralogy, and of chemistry. Of the three great divisions, or kingdoms of nature, the classification of the vegetable gives rise to systematic botany, that of the animal to zoology, and that of the mineral to mineralogy, which has for its subject the natural history of all the forms of unorganized matter. The relations of these to gravity, cohesion, light, electricity, and magnetism, belong to the domain of physics; while chemistry treats of their relations to each other, and of their transformations under the influences of heat, light, and electricity. Chemistry is thus to mineralogy what biology is to organography; and the abstract sciences, physics and chemistry, must precede, and form the basis of the concrete science, mineralogy. Many species are chiefly distinguished by their chemical activities, and hence chemical characters must be greatly depended upon in mineralogical classification. Chemical change implies disorganization, and all so-called chemical species are inorganic, that is to say unorganized, and hence really belong to the mineral kingdom. In this extended sense, mineralogy takes in not only the few metals, oxyds, sulphids, silicates, and other salts, which are found in nature, but also all those which are the products of the chemist's skill. It embraces not only the few native resins and hydrocarbons, but all the bodies of the carbon series made known by the researches of modern chemistry. The primary object of a natural classification, it must be re |