пу ар tany, zoology, and animal physiology. een to thirty, the latter number reprejest. The Philosophical Transactions ine and November,) which form a vola fourth part appears. Besides the d minutes are published monthly, and lumes, are entitled Proceedings of the MODERN THEORY OF BY CHARLES M. WETHI AFTER the electric current had been appl As the present sketch is intended less for c fused at the appearance of the formula Com chemical essays, the author may b le trite to chemists. He would also tak uch of Graham Otto many of the illust ments, employed in the present sketch. The nature of electrical attraction renders th try imperative, if we assume that electric ecode. Bias imagined the elementary atoms la ve and negative poles, but so that in the at ity predominated, while in that of anoth ery was in excess. This excess of (+ or acters to the element, making it positive or n electrical character are brought sufficien aily attract each other, forming a compound tive according to the predominance of o reity. The new compound atom was, ther action by another compound atom of differen ction becoming weaker as the compound atom Ampere imagined the atoms of positive elements ve atmospheres or envelopes, and atoms of th ve nuclei and positive envelopes. Hence a p coming together would mutually polarize each nuclei would draw them together to form a c EORY OF CHEMICAL TYPES. IARLES M. WETHERILL, PH. D., M. D. rrent had been applied to the decomposition of inorganic discovered that hydrogen, the metals, and the bases › pole, while oxygen, chlorine, and the acids were maniole, the assumption that electrical attraction was the nical combinations was very natural, and the electrog out of these experiments became speedily adopted by explained satisfactorily all known phenomena; it gained the discovery that the chemical elements and comby electricity from their combinations in the ratio of those days it was assumed, and at the present time it eory not embracing organic as well as inorganic comnable, and hence arose the radical theory, first applied afterwards thoroughly studied and developed in respect ch is intended less for chemists than for others who may pearance of the formulæ of organic compounds given in ys, the author may be pardoned in citing facts and ts. He would also take occasion here to accredit to the Otto many of the illustrations, as well as some of the n the present sketch. rical attraction renders the idea of binary compounds in if we assume that electricity is the bond of union in such the elementary atoms laden with electricity and with poles, but so that in the atom of one element the positive ed, while in that of another element the negative elecThis excess of (+ or −) electricity communicated its ent, making it positive or negative. If two atoms of dif cter are brought sufficiently near to each other, they other, forming a compound atom, which is itself positive - to the predominance of one kind or the other of its compound atom was, therefore, susceptible of further compound atom of different electricity, and so on, the eaker as the compound atom becomes more complex. he atoms of positive elements to have positive nucleï with or envelopes, and atoms of the negative elements to have ositive envelopes. Hence a positive and a negative atom would mutually polarize each other; the + and -E of aw them together to form a compound, and the E of oil of vitriol) possesses this prope 30. 80, according to the principles ju mpound, in which H is + and SO4 is or any metal, we will have sulphat the metal. SO, is, therefore, a compoun has been employed in chemistry, altho Vater and anhydrous sulphuric acid are generated by the decomposition of wa It is, however, more particularly in t pound radicals has been developed. The example of ammonia illustrates a seed it may at present be called inorgan The gas ammonia NH3 (in a manner an d) acquires basic properties only by the His the compound radical, ammonium pothetical group of atoms playing the The following table illustrates the par d simple inorganic radicals: Comp. radical ammonia. Lead, (Plumbum). 103.5 Silver, (Argentum) 108 Maganese. 27 Iron, (Ferrum). 23 Nickel 29 Cobalt. 30 Copper, (Cuprum). 31.7 Cerium Lanthanum 46 47 Didymium.. 48 Uranium... Molybdenum.. W Tugsten, (Wolfram) Gold, (Aurum).... Rhodium... 92 ...... 197 52 52 53 98.5 98.5 99.5 valents doubled to conform to the type theory. 60 48 69.5 When organic chemistry began to be dev Tere those containing different proportions ther with a few containing nitrogen. T norganic compounds, and the assumpt cals became imperative. For example, da radical (C4 Hs) called ethyl, the compo mparison with those of oxides of the diff and organic radical, which group of atoms Ethyle... Ether. Alcohol Chloride of ethyle.... Nitrate of the oxide of ethyle..... Acetate of the oxide of ethyle. Sulphate of the oxide of ethyle........ Sulphovinic acid.... Sulphovinate of the oxide of zinc.. Potassium.. Potassa... Hydrate potassa. Chloride potassium.. litmus nor form salts with bases; its compound with sesses this property. We may imagine this acid to be the principles just laid down; or to be H SO4, a binary is + and SO4 is. If for hydrogen we substitute potaswill have sulphate of potassa or the salt corresponding to refore, a compound radical in the sense in which the word chemistry, although it has not been isolated. When sulphuric acid are brought together, this compound radical composition of water in the manner illustrated above. e particularly in the case of the bases that the theory of s been developed. monia illustrates an inorganic compound radical; if, inat be called inorganic. NH3 (in a manner analogous to that of anhydrous sulphuric roperties only by the action of water; NH3, HO=NH, 0. I radical, ammonium. It has never been isolated; it is an f atoms playing the part of a metal. le illustrates the parallelism existing between compound radicals: emistry began to be developed, the compounds first studied ng different proportions of carbon, hydrogen, and oxygen, containing nitrogen. These were studied in their analogies ounds, and the assumption of a large number of organic perative. For example, if ether (C, H, O) were the oxide ) called ethyl, the compounds of ether could be brought into ose of oxides of the different metals, (C, Hs,) being a comcal, which group of atoms plays the part of a metal, thus: (C,Hs) (C4H5)O, SO3 + HO, SO3 K ко ко, но KCI n, so satisfactory in the explanation le, that the reluctance to abandon it, s influence, is natural. That it has ts fall, is owing to the present great scovery of phenomena which cannot to it. Ling, and the boundary line between ing more and more indistinct. If to and nitrogen has been assigned a on, the reason lies less, perhaps, in a than in the kind of experiments to ually, elements formerly called innd it is not too much to expect that een all of the elements as between f combining, in indefinite number of ise to so many "changes," i. e., comty-four elements could play an equal sounds would approach infinity, and arison. It would be no exaggeration from the earth of the fixed stars exof that great orbit in which our solar meet future wants; but, nevertheless, eory was becoming daily insufficient ed thoughtful men to invent a theory compounds, and bring them into the ir more perfect study possible. A ted, and chemists are loath to abanat of types pure and simple. urishing condition, certain newly obould substitute electro-negative chloound without changing the chemical Thus, by the action of chlorine (Cl) ists had many years ago discovered a e name of Dutch liquid, and which on this body the action of chlorine as discovered that a series of liquids ter as Dutch liquid, but differing in com by chlorine, thus: "2d 66 за 66 C1H2Cl CAHCI 66 hich demonstrates that in Dutch liquid and by atom, and another in which it unite The behavior of acetic acid with chlorine (C) and between the t similarity. They each saturate the same amo 2 C2 H CO, and C2 Cla Chor en, in which a portion of the hydrogen is of nascent hydrogen, chloracetic acid is te that these difficulties might be reconcile ve and positive character being assumed the same atom. This must be done in certa type theory in accord with the electro-che periments of Schoenbein upon ozone, and th ain bodies in the "nascent" state, would rd y; but the immediate result of the experi tro-chemical theory in abeyance, and to devel The first type theory was a theory of the cl nds, and was analogous to the natural history ders, genera, and species. There was a "mole |