712 



THE POPULAR SCIENCE MONTHLY. 



cause they could not cope with these enemies. 

 Sea snakes are common on some of the is- 

 lands, of three species, two of which are harm- 

 less, while the bite of the other is poisonous. 

 These sea snakes are highly prized, as vipers 

 are in Japan, and are used as food by the 

 rich and, to a smaller extent, as medicine by 

 the poor. 



Smoke. The following, from the Amer- 

 ican Engineer and Railroad Journal, seems 

 worthy of mention : A mistaken idea exists 

 as to the amount of actual carbon con- 

 tained in those dense masses of smoke 

 which are seen rising from the tall stacks 

 of manufacturing and other large plants. 

 By passing through water the gases aris- 

 ing from a furnace burning bituminous coal, 

 and weighing the solid particles retained 

 or precipitated, it has been proved, it is 

 claimed, that they amount to less than one 

 sixth of one per cent of the total amount of 

 coal consumed. It is not strange that a 

 different idea is entertained of the quantity 

 of actual carbon seemingly going to waste, 

 when the wonderful coloring power of the 

 finely divided particles of carbon is consid- 

 ered. To prove this it is only necessary to try 

 the well-known experiment of smoking a bit 

 of glass with a candle, and then mixing up 

 with a palette knife a portion of the coloring 

 matter thus secured with a drop or two of 

 gum arabic. A very small portion of this 

 mixture will color many quarts of water. The 

 actual carbon contained in the smoke itself is 

 inappreciable, but the unconsumed invisible 

 gases invariably associated with the smoke 

 are considerable in quantity and indicative 

 of a financial loss much larger than is gener- 

 ally known. 



Therapeutic Hypnotism. The unmis- 

 takable signs of the failing belief and in- 

 terest in hypnotism as a curative agent, and 

 its relegation to the field of curious if not 

 pathological psychology, is pointed out in 

 the editorial columns of the last Lancet. 

 The two deciding questions, about which 

 controversy has raged, have been, first, Are 

 hypnotic phenomena physiological or patho- 

 logical ? and, secondly, Has the induction of 

 hypnosis any therapeutic value ? A study of 

 the most successful hypnotic subjects seems 

 to indicate that the phenomenon is really a 



morbid one, and "associated with feebleness 

 of will and unusual impressionability," and 

 as regards its therapeutics, while it may be 

 of some value in certain functional nervous 

 diseases, such as hysteria and neurasthenia, 

 there are other methods of producing the 

 same effect which have none of the dangers, 

 both moral and physical, with which hypnosis 

 is fraught. 



Diphtheria and Milk. A curious epi- 

 demic of diphtheria following a sore throat, 

 caused by drinking a certain milk, is recorded 

 in the British Medical Journal. On the out- 

 break of the sore throat the milk and its 

 surroundings were closely examined : some 

 of the cows had sore teats ; but no disease 

 in the throats of either cows or milkers 

 could be discovered, and there were no Loef- 

 fler bacilli in the throat scrapings from the 

 patients. Upon boiling the milk before 

 using, the epidemic promptly subsided. But 

 within less than a week a true epidemic of 

 diphtheria appeared among these same peo- 

 ple, and, although careful investigation was 

 made, no source of secondary infection could 

 be discovered. It seems probable that the 

 throat trouble caused by the milk laid the 

 foundation for the diphtheritic bacillus. 

 The outbreak was a very mild one, only one 

 death occurring. 



Physical Measurements of School Chil- 

 dren. In J. Allen Gilbert's researches on the 

 mental and physical development of school 

 children, the results in the observations of 

 muscle sense, or sensitiveness to weight, 

 showed a gradual increase in ability to dis- 

 criminate, from six to thirteen years of age. 

 At thirteen there was a gradual falling off 

 and then another gain. Boys and girls, con- 

 sidered together, gradually increase in ability, 

 but when they are considered separately, 

 marked differences of sex appear. At six 

 years the considerable difference is in favor 

 of the boys ; at seven both sexes have the 

 same ability. From this on both gain with 

 equal pace to the age of thirteen, with the ex- 

 ception of an abrupt falling off for boys at 

 eleven. From thirteen to seventeen the dif- 

 ference again becomes manifest in favor of 

 boys. Ability to distinguish different shades 

 of the same color increases with age. The 

 balance of advantage in this test is slightly 



