CHEMISTRY. 



fattj acids, prepared by saponifying the butter, 

 and decomposing the soaps with dilute sulphu- 

 ric or hydrochloric acid; they were purified 

 by recrystallization from alcohol, fractionating, 

 etc. The new acids are represented by the 

 formulae CiaH a4 Oa and C^HusOa. The first is 

 the formula of lauric acid, but it melts at 57.5 

 (lauric acid melting at 43 Cent.), so it must 

 contain some acid of a higher melting-point 

 than lauric acid, and therefore the acid itself 

 must be lower in the series C n H 2n Oa than lauric 

 acid. The highest known acid in this series 

 is melissic acid, CsoH 8 o0 2 ; the new acid has a 

 formula not lower than CuHiasOa. The lower 

 acid crystallizes in pearly plates or fine long 

 needles. The higher acid for which the au- 

 thor proposes the name of " Theobromic Acid " 

 crystallizes in microscopic needles or gran- 

 ules, melts at 72.2 Cent., at a high temperature 

 distills apparently unchanged, and is somewhat 

 electric when dry a property which is pos- 

 sessed in a high degree by its silver salt. The 

 total fatty acids of cocoa-butter contain about 

 20 per cent, oleic acid. The author, in con- 

 clusion, points out that text-books state that 

 " cocoa butter yields, almost exclusively; stear- 

 ic acid." From the present investigations it is 

 clear that this statement is incorrect. It is 

 based entirely on determinations of the melt- 

 ing-point of the fatty acids obtained. 



Estimation of Alcohol in a Watery Mixture. 

 Dr. Werner Siemens has contrived an ingen- 

 ious apparatus, by which a stream composed 

 of alcohol and water, mixed in any proportion, 

 is so measured that a train of counter- wheels 

 records the volume of the mixture, while a 

 secured counter gives a true record of the 

 amount of alcohol contained in it. The modus 

 operandi is described as follows : 



The volume of liquid is passed through a revolv- 

 ing drum, divided into three compartments by radial 

 divisions, and not dissimilar in appearance to an or- 

 dinary wet gas-meter. The revolutions of this drum 

 produce a record of the total volume of passing 

 liquid. The liquid on its way to the measuring-drum 

 passes through a receiver containing a float of thin 

 metal filled with proof-spirit, which float is partially 

 supported by means of a carefully-adjusted spring, 

 and its position determines that of a lever, the an- 

 gular position of which causes the alcohol-counter 

 to rotate more or less for every revolution of the 

 measuring-drum. Thus, if water only passes through 

 the apparatus, the lever stands at its lowest position, 

 and tnen the rotative motion is not communicated 

 to the alcohol-counter, and this motion is rendered 

 strictly proportionate to the alcohol contained in the 

 liquid, allowance being made in the instrument for 

 the change of volume due to chemical affinity be- 

 tween the two liquids. 



Determination of Copper. A new method 

 of determining very small quantities of cop- 

 per is offered by J. M. Merrick, of Boston. 

 It is intended as a supplement to Bergeron 

 and L!H6_te's colorimetric test, which fails to 

 indicate a quantity of copper less than 0.5 

 milligramme. Mr. Merrick's method consists 

 simply in concentrating to a very small bulk 

 the solution suspected to contain copper, and 



then depositing the copper, if present, upon 

 platinum, by the battery. He uses for a de- 

 positing-cell a very small test-tube, on a foot 

 cut off so as to give a vessel about 1 inch 

 deep. Into this is introduced the solution 

 acidified with sulphuric acid, and a plati- 

 num anode and cathode each about an inch 

 long and one-eighth of an inch or lesa wide 

 are hung face to face, and very close together ; 

 and, the circuit being completed, very satisfac- 

 tory deposits of copper are obtained, with in- 

 credibly minute quantities of the metal. The 

 amounts are determined by the increased 

 weight of the cathode (which is provided with 

 a platinum wire soldered on with gold, by which 

 it can be hooked to a balance), and on the loss 

 of weight of the same after washing with nitric 

 acid. The platinum is polished and heated 

 red-hot before the first weighing, and then 

 gently heated before hanging in the solution. 

 The contrast in color between deposited cop- 

 per and bright platinum is, of course, striking 

 and characteristic. In this way, 0.1 milli- 

 gramme of copper may be, the author thinks, 

 safely determined ; while, for mere qualitative 

 analysis, this method may be employed where 

 the amount is even smaller. 



Theory of the Formation of Saline Deposits. 

 In a memoir on the origin of the boracic 

 acid of tho Tuscan suffbni, and sundry saline 

 deposits, especially those of Stassfurt, L. Dieu- 

 lafait (abstract of memoirs in American Jour- 

 nal of Science) lays down the general propo- 

 sition that " all saline substances existing in 

 mass, or in layers, in sedimentary formations 

 were originally a constituent of a normal sea," 

 i. e., of a sea of a constitution not essentially 

 different from our present sea. To establish 

 this proposition with regard to the borates, 

 he, in the first place, gives experimental evi- 

 dence that the water of the Mediterranean 

 contains at least two decigrammes of boracic 

 acid ia each cubic metre, and further, that, in 

 evaporating the brine, boracic acid accumu- 

 lates in the bittern until after the deposition 

 of the carnallite. In the second place, he in- 

 sists that, in the very characteristic deposits 

 of Stassfurt, the borates are found above the 

 carnallite, as we should expect if these deposits 

 were formed, as assumed, by the drying up of 

 extensive salt lakes. Again, having confirmed 

 the previous statements that the chief salt-beds 

 of the world are found on two geological hori- 

 zons, the Lias and the middle Tertiary, he gives 

 evidence that, in the Maremma of Tuscany, 

 where the suffoni occur, there is a saliferous 

 basin of the Tertiary period ; and he concludes 

 that the suffoni are not properly volcanic vents, 

 but that the surface-water percolating to the 

 salt-beds heated, it is true, by volcanic agency 

 determines well-known chemical changes, 

 from which result the peculiar acid-vapors 

 there discharged. But we can only give here 

 the barest outlines of an argument which is 

 worthy of careful study. 



M. Dieulafait also contributes in his paper 



