sities of the mouth than to the requirements of the ear; for, as stated above, one voice will give a simple harmonic curve for u, while another gives (at the same pitch) a double curve for a sound which is intended for the same letter in the same language, and which is at least generically the same vowel. This fact suggests that the mouth, being unable to shape itself so as to continue the simple form of the letter, adapts itself in some way so as to produce what may perhaps be termed an imitation. It is by no means impossible that this imitation may in some cases be produced by a recurrence to the form used for the same letter at a higher pitch. If this be so, then the hypothesis of a constant cavity for a given vowel sound would be true for the letter u when pronounced on notes an octave or a twelfth apart, although not for intermediate notes. When we examine the sound o we find less necessity for insisting on recurrence or any tuning of the mouth cavity. A fair approach to the phenomena observed might be obtained by assuming a constant mouth cavity, having a pitch of maximum resonance near b'b, as stated by Helmholtz, and reinforcing tones over a large range of nearly two octaves-from f" to f, or thereabouts. There are, however, some peculiarities in the constituents which suggest that the o cavity may also be adjustable. Our results are not inconsistent with the assumption that the cavity is slightly altered or tuned so as to bring the maximum resonance approximately into unison with that upper partial of the prime sung which lies nearest to b'. This hypothesis would allow us to diminish the very large range of reinforcement which the constant cavity theory requires, although even an adjustable cavity must still reinforce tones over a considerable range. Further experiments are required to determine how the mouth actually produces the results obtained, but is clear that the idea of relation between the constituents must be combined with that of absolute pitch in any complete vowel theory. The relation may, however, depend for some vowels, though hardly for u, on the simple range over which the reinforcement acts, The pitch of maximum resonance in the o cavity given by Helmholtz is b'b, and this, on either hypothesis, agrees well with our results. It is either the pitch of maximum resonance of the constant cavity, or the pitch near which the upper and strongest resonance is to be found, where the cavity is tuned. It may 5 B be VOL. IX. observed that, in the case of this letter, possibly the idea of a tuned cavity may be true for singing, and that of a constant cavity for speech. 7. On the Electric Conductivity of the Bars employed in his Measurements of Thermal Conductivity. By Prof. Tait. The following Gentleman was duly elected a Fellow of the Society : Dr J. J. KIRK DUNCANSON, 8 Torphichen Street. Monday, 17th June 1878. SIR WYVILLE THOMSON, Vice-President, in the Chair. The following Communications were read: 1. On the Biliary Secretion, with Reference to the Action of Cholagogues. Part II. By Professor Rutherford, F.R.S.S. L. and E., and M. Vignal. (Abstract.) The method of experiment by which the following results have been obtained has been described in the abstract of Part I., published in the "Proceedings" February 1877. All the experiments were performed on dogs. In the previous abstract the effects of 29 different substances were briefly stated: 30. Dilute nitro-hydrochloric acid is a hepatic stimulant of considerable power. 31. Jaborandi is a very feeble hepatic stimulant. 32. Calabar bean stimulates the liver, but not powerfully, unless it be given in very large doses. 33. Atropia sulphate antagonises the effect of Calabar bean on the liver, and thus reduces the hypersecretion of bile produced by that substance. It does not, however, arrest the biliary secretion; and when given alone, does not notably affect it. 34. "Menispermin," a resinous matter obtained from the Yellow Parilla, does not stimulate the liver. It slightly stimulates the intestinal glands. 35. "Baptisin," a resinous matter derived from the Baptisia tinctoria, is a hepatic and also an intestinal stimulant of consider able power. It 36. "Phytolaccin," a resinous matter prepared from the Phytolacca decandra, is a hepatic stimulant of considerable power. also slightly stimulates the intestinal glands. 37. Sodium Benzoate is a powerful stimulant of the liver. It does not stimulate the intestinal glands. 38. Ammonium Benzoate stimulates the liver, but not quite so powerfully as the sodium salt of benzoic acid. It does not stimulate the intestinal glands. 39. Benzoic acid stimulates the liver, but owing to its insolubility, its action is less rapid and much less powerful than that of its salts. 40. Sodium Salicylate is a powerful hepatic stimulant. It does not notably stimulate the intestinal glands. 41. Ammonium Phosphate is a moderately powerful stimulant of the liver. It is not an intestinal stimulant. 42. Tannic acid does not affect the biliary secretion. 43. Hyosciamus does not notably affect the biliary secretion, and does not prevent such a stimulant as sodium salicylate from augmenting it. 44. Morphia does not affect the biliary secretion, and does not prevent the stimulating effect of such a substance as sodium salicylate. 45. Pure diluted alcohol does not affect the biliary secretion. 46. Potassium iodide does not affect the biliary secretion. 47. Veratrum viride has no notable effect on the biliary secretion. 48. Manganesium sulphate is not a hepatic stimulant. It powerfully stimulates the intestinal glands, and like other purely purgative agents, such as magnesium sulphate and gamboge, it indirectly lowers the biliary secretion. 49. Ailanthus glandulosus is an intestinal but not an hepatic stimulant. 50. Acetate of lead somewhat diminishes the biliary secretion, probably by a direct action on the liver. 51. "Hydrastin," a resinous matter, prepared from the root of the Hydrastis canadensis, is a hepatic stimulant of considerable power. It also slightly stimulates the intestinal glands. 52. "Juglandin," a resinous matter, prepared from the root of the Juglans cinerea, is a hepatic stimulant of considerable power. It also slightly stimulates the intestinal glands. Thus, by means of a new and precise experimental method, the physiological pharmacology of one of the most important organs of the body has been in this research worked out as far as at present it appears desirable to proceed, and knowledge that is definite and reliable, because obtained by a method of accurate measurement, after the elimination of disturbing factors, has by this research been substituted for the vague traditions of the past. The effects of fifty-two medicinal agents upon the liver have been investigated, and the vast majority of the conclusions are in complete harmony with the results of clinical observation. Very many new facts are, however, given to the physician, and even as regards wellknown substances, our knowledge of their effects on the liver is now of a character very different from that which previously obtained. All the experiments relate to the bile-secreting and not to the bileexpelling mechanism. The authors do not intend to investigate the effects of medicinal agents on the latter, as this point appears to them one of very minor importance compared with the subject of the above research. The following remarks indicate the position in pharmacology of the above results. Of necessity, the influence of a drug upon a diseased state is the ultimatum of pharmacology, and every experiment upon a healthy bodily system, whether of man or animal, is merely ancillary to experiments with the drug in disease. Having discovered that this or that drug stimulates the healthy liver of a dog, we do not infer that it must also stimulate the human liver in health, and still less do we conclude that it must also have this action in disease. The experiments on the healthy liver of the dog, on the normal and on the abnormal human liver, are three sets of experiments closely related, but still distinct. The facts derived from any one of the three sets cannot be substituted for those of the other two. Each set of facts has its own proper place. The above research, therefore, leaves it to the clinical observer to experiment on man with such substances as sodium benzoate, sodium salicylate, baptisin, euonymin, sanguinarin, &c., and thereby to ascertain whether or not these substances also stimulate the human liver; and of necessity it is also left to him to ascertain in what diseased state the employment of this or of that substance is most advantageous. Other general conclusions have been already stated at the close of Part I. 2. On a New General Method of Preparing the Primary Monamines. By R. Milner Morrison, D.Sc. 3. On the Preparation and Properties of Pure Graphitoid and Adamantine Boron. By R. M. Morrison, D.Sc., and R. Sydney Marsden, B.Sc. 4. On Colour in Practical Astronomy, spectroscopically examined. By Professor Piazzi Smyth. Monday, 1st July 1878. SIR WYVILLE THOMSON, Vice-President, in the Chair. The following Communications were read: 1. On the Disruptive Discharge of Electricity. By Alexander Macfarlane, D.Sc., and P. M. Playfair, M.A. (Abstract.) During the months of May and June of this session, we have endeavoured to investigate certain questions suggested by our experience of the discharge of electricity through the gases and through oil of turpentine. Ordinary paraffin-oil, when used as a dielectric, exhibits the same phenomena as oil of turpentine. Gas is liberated by the passage of the spark, and at the same time carbon is deposited. Once produced, the gas bubbles make the passage of the spark more easy through bringing the electrified surfaces nearer to one another; hence, |