28 & F. Peckham — Petroleum in its 



made and skillfully reduced, have formed the opinion that 

 neither the law of Weber, nor Fechner's formula is correct, 

 and a priori considerations lead them to the opinion that 

 it is probable that the sensation is directly as the stimulus. 

 If the sensation increases directly as the stimulus, then we 

 can obtain the relative sensations of two sounds whose relative 

 energies are known. Adopting this relation, we have 1 : 4 as 

 the ratio of the maximum sensation in the periods taken for 

 those of much diminished sound to the maximum sensation in 

 the periods of much increased sound, as given by the measure- 

 ments of the amplitudes of the resultant curves of the nearest 

 consonant intervals. 



In explanation of the facts and laws given in this paper I 

 have no hypothesis to offer. It appears to me that the present 

 condition of our knowledge of audition demands that we 

 should ascertain more facts relating to it before we frame 

 hypotheses on the mechanism and action of the apparatus of 

 hearing. 



Stevens Institute of Technology, Hotaoken, N. J. 



Apt. II. — Petroleum in its relations to Asphaltic Pavement', 

 by S. F. Peckham. 



[Read at the "World's Congress of Chemists, Chicago, 111., Aug. 25th, 1893.] 



The chemical examination of petroleum has been conducted 

 along two different lines of research. Sometimes one has 

 been followed to the exclusion of the other and sometimes the 

 two have been combined. The method most familiar to 

 chemists is that of distillation, usually more or less destruc- 

 tive. The less well known method consists in separating the 

 constituents of the petroleum by the successive application of 

 solvents, in the use of which term I propose in this paper to 

 exercise considerable latitude. 



The earliest analysis of petroleum is described by de Saussure 

 in a paper published in the Bibliotheque Universelle in 18 L7.* 

 He examined the so-called naphtha of Amiano, a very light 

 and almost colorless petroleum. He purified it by distillation 

 and determined the percentage composition, as if it were an 

 homogeneous substance. Twenty years later, in 1837, f Bous- 

 singault published his celebrated memoir on the composition 



* Bibliotheque Universelle, iv, 116; Annales de Chemie et de Physique (2), 

 iv, 314-340; London Journal of Science, iii, 411. 



\ Annales de Chemie et de Physique (2), Ixiv, 141 ; Journal of the Franklin 

 Institute, xxiv, 138; New Edinburg Philosophical Journal, xxii, 97. 



