3 8z 



THE POPULAR SCIENCE MONTHLY 



tained by distillation from oil of thyme, 

 occurs in white, highly-aromatic crystals ; 

 when dissolved in hot water in the propor- 

 tion of one part per 1,000 it forms a fully- 

 saturated solution possessing a neutral re- 

 action. More concentrated watery solu- 

 tions cannot be obtained, for, when dis- 

 solved in greater proportions than one in 

 1,000, the thymol evaporates. Lewin finds 

 that 0.1 per cent, of this solution is suffi- 

 cient to prevent fermentation in sugary 

 liquids, no matter what the proportion of 

 sugar and yeast. Milk to which a small 

 quantity of the thymol solution was added 

 did not begin to show signs of coagulation 

 till twenty days later than milk with which 

 an equal quantity of water had been mixed. 

 Filtered white of egg in contact with the 

 air was found to grow putrid in three or 

 four days, whereas white of egg with which 

 thymol-water had been mixed gave not the 

 slightest indication of putridity after eleven 

 weeks. The same results were obtained in 

 treating pus with water and thymol : pus so 

 treated at once lost its putrid odor, and con- 

 tinued to be odorless for five weeks, or until 

 it had become dry. 



The English Commission on Vivisec- 

 tion. The Royal Commission appointed in 

 England to inquire into the subject of ex- 

 perimentation on living animals, for scien- 

 tific purposes, have reported unanimously 

 against the absolute prohibition of this 

 practice. " Our conclusion is," says the 

 report, " that it is impossible altogether to 

 prevent the practice of making experiments 

 upon living animals for the attainment of 

 knowledge applicable to the mitigation of 

 human suffering or the prolongation of hu- 

 man life ; that the attempt to do so could 

 only be followed by the evasion of the law, 

 or the flight of medical and physiological 

 students from the United Kingdom to for- 

 eign schools and laboratories, and would, 

 therefore, certainly result in no change fa- 

 vorable to the animals ; that absolute pre- 

 vention, even if it were possible, would not 

 be reasonable ; that the greatest mitigations 

 of human suffering have been in part de- 

 rived from such experiments ; that by the 

 use of anaesthetics in humane and skillful 

 hands the pain which would otherwise be 

 inflicted may, in the great majority of cases, 

 be altogether prevented, and in the remain- 



ing cases greatly mitigated ; that the inflic- 

 tion of severe and protracted agony is in 

 any case to be avoided ; that the abuse of 

 the practice by inhuman or unskillful per- 

 sons in short, the infliction upon animals 

 of any unnecessary pain is justly abhor- 

 rent to the moral sense of Englishmen gen- 

 erally, not least so of the most distinguished 

 physiologists and the most eminent sur- 

 geons and physicians ; and that the support 

 of these eminent persons, as well as of the 

 general public, may be confidently expected 

 for any reasonable measures intended to 

 prevent abuse." 



Perception of Musical Tones. From the 

 researches of Prof. Preyer, of Jena, on the 

 " Limits of Perception of Musical Tones," 

 it appears that the minimum limit for the 

 normal ear is from sixteen to twenty-four 

 vibrations per minute, and the maximum 

 forty-one thousand vibrations, though per- 

 sons with average powers of hearing were 

 found to be absolutely deaf to tones of six- 

 teen thousand, twelve thousand, or even 

 fewer vibrations. Silence, according to 

 Preyer, is a state of uniform minimum ex- 

 citation of the auditory nerve-fibres. Si- 

 lence is to the ear precisely what black is 

 to the eye. The pressure of the fluid con- 

 tents of the labyrinth and the flow of blood 

 through the vessels must give rise to sen- 

 sations of which we are unconscious only 

 because of their uniformity, their constan- 

 cy, and their low degree of intensity. Si- 

 lence, when the attention is concentrated 

 on the sense of hearing, is found to vary in 

 degree just as the blackness of the visual 

 field, when light is excluded from the eye, 

 has been observed to vary. Lastly, the 

 parallel between the auditory sense and the 

 visual is borne out by a study of the ento- 

 tic (intra-aural) sensations, which are closely 

 analogous to well-known entoptical (or in- 

 tra-ocular) phenomena. 



Dr. Mohr on the Source and Composition 

 of Meteorites. From an examination of a 

 large number of meteorites, Dr. Mohr, in 

 Liebig's Annalen der Ckemie, concludes 

 that these bodies must have been formed 

 upon a planet warmed by the sun, or by a 

 sun in absolute rest, and in the lapse of an 

 enormous length of time. Under what cir- 

 cumstances this planet has been shivered 



