86o 



THE POPULAR SCIENCE MONTHLY. 



that those of 1S67 and 1S68 were much less 

 than those of 1860 and 1861, on the one 

 hand, and of 1871 and 1872 on the other; 

 and that the number and duration of the 

 cyclones of 1879 and 1880 were much less 

 than those of the cyclones of 1871, 1872, 

 and 1884 ; but it appears that in 1884 there 

 was less cyclcne activity than in 1861 and 

 1872. 



Antiseptics and Disinfectants. The 



Committee on Disinfectants of the Ameri- 

 can Public Health Association calls atten- 

 tion in its report to a distinction which is 

 not always accurately enough observed be- 

 tween disinfectants substances which de- 

 stroy germs and simple antiseptics which 

 prevent their development. Many of the 

 preparations put on the market as dis- 

 infectants are in reality only antiseptics. 

 While practically the words disinfectant, in 

 its strict sense, and germicide, are consid- 

 ered to mean the same thing, so long as it 

 is not proved that all infections are de- 

 veloped from germs, we must regard " dis- 

 infectant " as a word of more general sig- 

 nificance than germicide. But, as a matter 

 of fact, those agents which by laboratory 

 experiments have been proved to be the 

 most potent germicides have also been 

 shown to be the most reliable disinfectants. 

 While antiseptic agents may fail to fulfill 

 the stronger purpose of disinfectants, they 

 are known to exercise a restraining influ- 

 ence on the development of disease-germs, 

 and their use during epidemics is recom- 

 mended, when masses of organic material 

 in the vicinity of human habitations can not 

 be completely destroyed or removed, or dis- 

 infected. A substance of this kind is sul- 

 phate of iron, or copperas, which, while it 

 does not destroy the vitality cf disease-germs 

 or the infecting power of material contain- 

 ing them, is a very valuable antiseptic, the 

 low price of which makes it one of the most 

 available agents for the arrest of putrefac- 

 tive decomposition. While an antiseptic 

 agent is not necessarily a disinfectant, all dis- 

 infectants are antiseptics ; for putrefactive 

 decomposition is due to the development of 

 germs of the same class as that to which 

 disease-germs belong, and the agents which 

 destroy the latter also destroy the bacteria 

 of putrefaction when brought in contact 



with them in sufficient quantity, or restrain 

 their development when present in smaller 

 amounts. Antiseptics are a poor substitute 

 for cleanliness. 



Wind-Carving in Maine. Mr. George 

 II. Stone discusses, in the " American Jour- 

 nal of Science," some instances of wind- 

 action on till and bowlders which he has 

 observed in Maine. One of the features of 

 the surface geology of this State is the large 

 areas of sand which were deposited by most 

 of the rivers along the lower part of their 

 courses during the Champlain epoch. The 

 valley of the Androscoggin is particularly 

 distinguished by its sand-dunes. Not rarely 

 spots bare of vegetation can be found on 

 hill-sides exposed to high winds, where, dur- 

 ing dry days, the wind removes the finer 

 parts of the till and drives the gravel back 

 and forth just as happens in Colorado dur- 

 ing the dry winter weather. The effects of 

 this process are, however, usually obliter- 

 ated or obscured by the frequent rains and 

 abundant snows ; but the wearing marks of 

 the action are plainly observable in many 

 cases, as on the top of a hill near Wayne 

 village. At Bethel are found bowlders which 

 exhibit on one or more of their surfaces 

 grooves, scratches, strias, and polishings, the 

 origin of which was for a long time prob- 

 lematical ; and similarly marked stones have 

 been noticed at Gilead and in Gorham, New 

 Hampshire, all near the Androscoggin Riv- 

 er. Mr. Stone believes that he solved the 

 mystery of these marks during his investi- 

 gation of the glacial gravels of the region 

 in the summer of 1885. In numerous places, 

 at Bethel and elsewhere, he found " bowl- 

 ders and even small stones which are now 

 being sand-carved by the wind as plainly 

 and incontestably as in Colorado. The drift- 

 ing dunes of fine sand do not produce this 

 effect to any great extent, probably because 

 the stones are covered and uncovered too 

 rapidly. But there are bare spots not pro- 

 tected by grass where coarse sand and grav- 

 el are driven back and forth by the wind, 

 and here the carved bowlders can be seen 

 in considerable numbers and in all stages 

 of the process. In some cases it appeared 

 probable that these bare places were where 

 drifting sand had swept over the surface 

 and the till had been partially denuded by 



