he solids examined, antimony delivers the smallest, and tin the largest drops. Law 6.-The drop-size depends upon temperature; generally, the higher the temperature the smaller the drop. With water, the effect of a change of temperature of 20° C. about 30° C. is very small. Law 7.-The nature or tension of the gaseous medium has little or no effect upon drop-size. SLL. Law 8.-The drop-size of a liquid which drops under like conditions through various media, does not depend wholly upon the density of the medium and consequent variation in the weight, in the medium, of the dropping liquid. Law 9.—If there be two liquids, A and B, which drop under like conditions through air, and the drop-size of the one, A, be greater than the drop-size of the other, B, then if a third liquid, C, be made to drop through A and through B, the drop-size of C through A is greater than the dropsize of C through B. Law 10.-If the drop-size of A through B be greater than the dropsize of A through C, then the drop-size of a fourth liquid, D, through B is also greater than the drop-size of D through C. Law 11.-If a liquid, A, drop under like conditions in succession through two liquids, B and C, then its drop-size through any mixture of B and C is intermediate between its drop-size through B and its drop-size through C. Corr. And the greater the proportion of in the mixture the more B nearly does the drop-size of A through the mixture approach to the dropsize of A through alone. B Law 12.—The drop-size of any mixture of two liquids, A and B, dropping through a third liquid, C, is intermediate between the drop-size of A A through C and that of B through C; and the greater the proportion of A B in the mixture, the more nearly does the drop-size of the mixture approach to the drop-size of alone, whether the dropping liquid be heavier or lighter than the liquid medium. Law 13.-If the liquid X has a larger drop-size than the liquid Y in the liquid Z, then the liquid Z has a larger drop-size in X than it has in Y. Law 14.—If a liquid, X, has a larger drop-size than a liquid, Y, in air, then the drop-size of X through Y is larger than the drop-size of Y through X. Law 15.-If the drop-size of X be greater than the drop-size of Y in air, and the drop-size of Y be greater than the drop-size of Z in air, then the ratio between the drop-sizes of X in any mixture of Y and Z, and the drop-size of that mixture of Y and Z through X, is greatest when the ratio between Y and Z is unity. IV. "On the Chemical Constitution of Reichenbach's Creosote."Preliminary Notice. By HUGO MÜLLER, Ph.D. Communicated by WARREN DE LA RUE, F.R.S. Received October 1, 1864. This substance, which has been discovered by Reichenbach amongst the products of destructive distillation of wood, has been repeatedly the subject of chemical investigation, but owing to the difficulty attending its purification, the chemical nature of creosote remained doubtful until 1858, when Hlasiwetz published his elaborate research on this subject. Up to that time Reichenbach's creosote was frequently confounded with phenol (phenylic alcohol, carbolic acid); and, indeed, the latter had very nearly supplanted the true creosote in its application. Hlasiwetz first prepared the creosote in a chemically pure state, and ascertained its chemical formula to be C, H, O, and showed that this substance, although having some characteristic properties in common with phenol, was a distinct chemical substance, and otherwise in no way related to this body. 10 At the time of publication of Hlasiwetz's memoir I was myself engaged with the investigation of creosote prepared from wood-tar; and such results as I had then arrived at completely coincided with those obtained by Hlasiwetz. Having a considerable quantity of pure material at my disposal, I took up this subject again, with the view of obtaining some insight into the chemical constitution of creosote, and I think I am now able to lay before the Society a few results which may serve as a contribution towards the solution of the questions at issue. I will reserve a full description of my experiments for a future occasion, and confine myself in this communication merely to the description of one reaction, which I consider best calculated to illustrate the results I have obtained. When pure creosote, boiling constantly (in hydrogen) at 219°C., is brought into contact with concentrated hydriodic acid and heated to boiling, it is acted upon, iodine is set free, and iodide of methyl distils over. As the free iodine interferes with the result of the reaction, I varied the experiment by substituting iodide of phosphorus for hydriodic acid, in the following manner the creosote is shaken up with a small quantity of water, of which it dissolves a certain portion, then ordinary phosphorus is introduced, and the whole gently warmed. The iodine is now added in small quantities at a time, care being taken that there is always an excess of phosphorus after the iodine has been converted into iodide of phosphorus. If the temperature is now gradually raised to about 95° C., the reaction makes itself manifest by the evolution of vapour of iodide of methyl, which distils over, and which is condensed in an ice refrigerator. As soon as the reaction diminishes, fresh portions of phosphorus and iodine are added, and the experiment so continued until the substance in the retort becomes gradually thicker and thicker, and viscid if allowed to cool. The distillate collected in the receiver consists mainly of iodide of methyl mixed with some unaltered creosote, from which it is readily liberated by distillation, and agitation with a solution of caustic alkali. The residue contained in the retort, on being mixed with water, now readily dissolves, with the exception of a small quantity of a heavy brown oil which contains unaltered creosote. The aqueous solution is mixed with a large quantity of water and partly saturated with carbonate of barium, the clear liquid filtered off and precipitated with acetate of lead, the white precipitate well washed and decomposed with sulphuretted hydrogen. The sulphide of lead having been filtered off, the aqueous solution is now carefully evaporated at a low temperature, when a thick heavy liquid is obtained, which in its reactions so closely resembles pyrocatechine or oxyphenic acid, that one would be inclined to consider it identical with this substance if it were not for the apparent impossibility of obtaining it in a crystalline form. I am still engaged with the determination of the composition of the latter substance; but, from its chemical nature, so far as I have made myself acquainted with it, and from other considerations, I think it more than probable that this substance bears the closest analogy to oxyphenic acid (C. H. O1), and is in all probability its homologue. The described decomposition of creosote may be expressed in the following way : According to which creosote may be considered as methylated oxytolylic acid, or oxykressylic acid. This view gains in probability if we consider the general properties of creosote, and the fact that a lower homologue of creosote, together with free oxyphenic acid, exists amongst the products of distillation of wood. Hlasiwetz has moreover shown that guaiacol is identical with this lower homologue of creosote, which it resembles in every respect. 10 If the constitution of creosote (C, H1, O2) turns out to be as stated above, guaiacol (C, H, O2) may be regarded as methylated oxyphenic acid, and we may therefore expect to obtain by the action of hydriodic acid upon this substance, iodide of methyl and oxyphenic acid. I am about to carry out the latter experiment. V. "Researches on the Colouring Matters derived from Coal-tar.No. IV. Phenyltolylamine." By A. W. HOFMANN, LL.D., F.R.S. Received October 19, 1864. The discovery of diphenylamine among the products of decomposition furnished by the destructive distillation of aniline-blue (triphenylic ros aniline) which I have lately communicated to the Royal Society (Proceedings, June 16, 1864), naturally suggested the investigation of analogously constituted bodies in a similar direction. My attention has in the first place been directed to the study of a compound which, from its mode of formation, ought to be designated as toluidine-blue. When a salt of rosaniline (the acetate for instance) is heated with double its weight of toluidine, phenomena present themselves which are similar to those observed in the analogous experiment with aniline. In the course of a few hours the rosaniline passes through all the different shades of violet, and is ultimately converted into a dark lustrous mass, which dissolves in alcohol with a deep indigo-blue colour. This substance is the acetate of tritolylrosaniline. By treatment with alcoholic ammonia, and subsequently addition of water to the solution, the free base is easily obtained, from which the several salts may be prepared by the usual processes. I have examined only one of these salts, viz. the hydrochlorate. Repeatedly crystallized from boiling alcohol, this salt is obtained in small blue crystals insoluble in water, which at 100° C. contain The formation of toluidine-blue is thus seen to be perfectly analogous to that of aniline-blue. I have not examined in detail the properties of this new series of colouring matters. Generally speaking they are more soluble than the corresponding phenyl-compounds, and therefore less easily obtained in a state of purity. When one of these salts (the acetate for instance) is submitted to dry distillation, water and acetic acid are evolved in the first place; then follow oily products, which, as the temperature rises, become more and more viscid and ultimately solidify into crystalline masses, ammonia being abundantly evolved during the latter stages of the process. Unless the operation has been carried out on rather a large scale, a comparatively small amount of a light porous charcoal remains in the retort. The oily distillate contains several bases. Those boiling at a low temperature are almost exclusively aniline and a little toluidine. The principal portion of the products boiling at a higher temperature is a beautifully crystallized base which is easily purified. By pouring cold spirit upon the interwoven crystals, a brown mother liquor containing other bases is readily separated; the residuary substance has only to be crystallized from boiling alcohol in order to procure a compound of perfect purity. The chemical deportment of the new substance is very similar to that of diphenylamine. Like the latter it unites with acids, forming salts of very little stability, splitting up into their constituents under the influence of water, of heat, and even by mere exposure in vacuo. In contact with nitric acid the crystals at once assume a blue coloration, with an admixture of green, but nevertheless so similar to the analogous colour-reaction of diphenylamine, that by this test alone the two substances could not possibly be distinguished. The two bases differ, however, essentially in their solubility, their fusing- and boiling-points, and lastly in their composition. The new base is far less soluble in alcohol than diphenylamine; it fuses only at 87° C., while the fusing-point of diphenylamine is 45° C.; the boiling-point of the new base is 334.5° C. (corr.), at which temperature it distils without any decomposition, while diphenylamine boils at 310° (corr.). The results of analysis lead to the formula A hydrochlorate, crystallizing in little plates, and obtained by the addition of concentrated hydrochloric acid to an alcoholic solution of the base, when dried over lime, was found to contain Formation and chemical deportment characterize the new base as the mixed secondary monamine of the phenyl- and tolyl-series, as phenyltolylamine*, In consequence of the simultaneous existence in the molecule of the new base of the radicals phenyl and tolyl, its deportment under the influence of dehydrogenating agents became of considerable interest; and indeed, having recognized the nature of the compound, my first experiment consisted in submitting it to the action of corrosive sublimate. Both substances unite to form a dark brown mass which, after having been heated, dissolves in alcohol with a magnificent violet-blue colour. The compound thus produced exhibits the behaviour of the colouring matters generated from rosaniline by substitution. Owing to the peculiar properties of this class of substances, it would be difficult to prepare the new compound in sufficient * It deserves to be noticed that the percentages of carbon in diphenylamine, phenyltolylamine, and ditolylamine nearly coincide. The percentages of hydrogen, however, unequivocally distinguish the three. compounds. The analysis of phenyltolylamine furnished the following numbers: |