TOPICAL MEDICATION IN PHTHISIS.
Dr. G.H. Mackenzie reports in the Lancet an acute case of phthisis which was successfully treated by him by causing the patient to respire as continuously as possible, through a respirator devised for the purpose, an antiseptic atmosphere. The result obtained appears to bear out the experiments of Schüller of Greifswald, who found that animals rendered artificially tuberculous were cured by being made to inhale creosote water for lengthened periods. Intermittent spraying or inhaling does not produce the same result. In order to insure success the application to the lungs must be made continuously. For this purpose Dr. Mackenzie has used various volatile antiseptics, such as creosote, carbolic acid, and thymol. The latter, however, he has discarded as being too irritating and inefficient. Carbolic acid seems to be absorbed, for it has been detected freely in the urine after it had been inhaled; but this does not happen with creosote. As absorption of the particular drug employed is not necessary, and therefore not to be desired, Dr. Mackenzie now uses creosote only, either pure or dissolved in one to three parts of rectified spirits. "Whether," says he, "the success so far attained is due to the antidotal action of creosote and carbolic acid on a specific tubercular neoplasm, or to their action as preventives of septic poisoning from the local center in the lungs, it is certain that their continuous, steady use in the manner just described has a decidedly curative action in acute phthisis, and is therefore, worthy of an extended trial."
ON THE LAW OF AVOGADRO AND AMPERE.
The Scientific American Supplement of May 14,1881, contains, under this head, Mr. Wm. H. Greene's objections to my demonstration (in No. 270 of the same paper) of the error of Avogadro's hypothesis. The most important part of my argument is based on the evidence afforded by the compound cyanogen; and Mr. Greene, directing his attention to this subject in the first place, states that because cyanogen combines with hydrogen or with chlorine, without diminution of volumes, I have concluded that the hypothesis falls to the ground. This statement has impressed me with the conviction that Mr. Greene has failed to perceive the difficulty which is at the bottom of the question, and I will, therefore, present the subject more fully and comprehensively.
The molecule of any elementary body is, on the ground of the hypothesis, assumed to be a compound of two atoms, and the molecule of carbon consequently C2=24; that of nitrogen N2=28. Combination of the two, according to the same hypothesis, takes place by substitution; the atoms are supposed to be set free and to exchange places, forming a new compound different from the original only in this: that each new particle contains an atom of each of the two different substances, while each original particle consists of two identical atoms. The product is, therefore, assumed to be, and can, under the circumstances, be no other than particles of the composition CN and weight 26. These particles are molecules, according to the definition laid down, just as C2 and N2; but there is this essential difference, that the specific gravity of cyanogen gas, 26, coincides with the molecular weight, while the assumed molecular weight, N2=28, is twice as great as the specific gravity of the gas, N=14.
In using the term molecular weight, it is to be remembered that it does not express the weight of single molecules, but only their relative weight, millions of millions molecules being contained in the unit of volume. But on the hypothesis that there is the same number of molecules in the same volume of any gas, the specific gravities of gases can be, and are, identified with their molecular weights, and, on the ground of the hypothesis again, the unit of the numbers which enter into every chemical reaction and constitute the molecular weight, is stipulated to be that contained in two volumes.