May 20, 1887.] 



SCIENCE. 



48T 



getting the amount held -within the interstices of 

 the media. 



In those filters in which the mechanism or media 

 is reversed for cleansing, the organic matter upon 

 which the microbes are feeding and multiplying, and 

 which has become attached to the walls of the spaces 

 of the filtering media, are not removed, any more 

 than the greenish sctim is removed from the stones 

 in a rapidly flowing brook : on the contrary, so 

 tenacious is this material, that it forms in strings 

 and streamers pointing with the current. 



As is well known, commencing at the set bowl in 

 a dwelling-house, a deposit forms upon the sides of 

 the waste-pipe, continues downward, adhering to 

 the sides of the trap and continuing to the drain- 

 pipe and sewer, till it reaches the point of delivery. 

 This deposit is, of course, composed of the wastes 

 which have been thrown into the bowl, and which is 

 fully charged with organisms whose function is to 

 destroy and assist in natiire's retrograde metamor- 

 phosis. The strongest flushing of this pipe does not 

 remove the slime from its sides : how, then, can a 

 retarded pressure of water wash away the organic 

 matter adhering to the sides of oiTr meshes of felt 

 and our granules of quartz and charcoal ? 



The number of microbes in a given sample of 

 water serving to render it harmful, has not been 

 actually determined, any more than a specimen can 

 be condemned for the amount of albuminoid, am- 

 monia, or chlorine alone which it contains ; still a 

 water containing over a thousand microbes or colonies 

 to the cubic centimetre of water is the highest limit 

 consistent with purity in drinking-water. A water 

 which contains fifty bacteria to the cubic centimetre 

 before filtration will increase to over a thousand in 

 seven days' use, no matter how much care is taken 

 to cleanse the filter short of absolute sterilization. 



The point of danger, however, lies in the fact that 

 the two diseases which are communicable by inges- 

 tion into the alimentary canal of the escrement 

 from them (typhoid-fever and cholera) are the ones 

 which are liable to find their way into drinking- 

 water from contamination by sewage finding its way 

 into river and well supplies. 



I am at present condTicting experiments to deter- 

 mine how rapidly the germs of typhoid may increase 

 within filters in the presence of sterilized water and 

 in presence of the bacteria of drinking-water. 



Gaedneb T. Swakts. 



An American dialect society. 



Is it possible to establish such an institution ? It 

 is certainly time. Year after year the older districts 

 of the United States and Canada are getting less and 

 less distinguished by those peculiarities in their A^er- 

 nacular which to the student of history and phi- 

 lology are of the utmost interest. Public schools, 

 many newspapers, cheap books, a taste for reading, 

 a notion that ' old-time ' ways and dialect are not 

 ' elegant,' and, above all, the more constant com- 

 munication between different parts of the country, 

 are doing much to tone down the peojjle of the 

 United States to what, from the philologist's point of 

 view, is one dead level. In time the mountaineers of 

 Tennessee and the hill country of the Carolinas, the 

 ' crackers ' of Georgia, and the picturesquely talking 

 folk of the Arkansas bottoms and the lower Missis- 

 sippi, will have lost many of their present peculiari- 

 ties of speech. Even the New-Englanders, I am 



told (for I have not lived in America for more than 

 twenty years), are fast abandoning many of those 

 dialectic peculiarities which to a philologist are so 

 suggestive. Even the Virginians, since they have 

 gone into the great world, are no longer so readily 

 ' berayed ' by their speech. Now, therefore, is the 

 time to collect vocabularies of these local dialects, 

 with si^ecimens gleaned from printed works illus- 

 trating the use of any particular word. Books, al- 

 manacs, election-addresses, and a host of similar 

 ephemeral literature, might be gathered and de- 

 posited in the national librarj'. Mr. Cable, by his 

 novels, has done much to preserve the quaint Creole 

 Louisianian speech ; Mr. Johnston has in the same 

 way done as much for the Georgian dialect; Miss 

 Murfree for the Tennessee mountaineers; Mr. Page 

 for the Virginians ; a host of writers, imprimts Mr. 

 Lowell, for the New-Englanders ; and, not to go over 

 the long roll of writers in American dialects, Mr. 

 Harris has shown us what a wealth of folk-lore and 

 folk-speech there is to be garnered among the south- 

 ern negroes. Biit the next generation will have no 

 such easy task as the present one. Even in slow- 

 going England the Folk-lore society and the English 

 dialect society came quite late enough into the field, 

 and found that in a few years more the school boards 

 and the desire to be ' genteel ' would have effectually 

 effaced those old-world differences of tongue which 

 even in 1598, when Puttenham was writing his ' Arte 

 of English poesie,' had begun to be blurred. Al- 

 ready many a precious relic of the past has been 

 forever lost, and we can only be thankful that so 

 much has been preserved. In America — I speak, of 

 course, of the old colonial sections — there still 

 linger peculiarities, and even bits of folk-lore, which 

 have vanished out of the districts in the mother- 

 countries from which the immigrants came. Now, 

 therefore, is the time for snatching up what still re- 

 mains, and I question whether there are not in the 

 United States and in lower Canada quite as many 

 dialects as there are in England. The 'Pennsylvania 

 Dutchman ' has even yet peculiarities in speech 

 easily detected by those who know them, and there 

 is scarcely an old state of the Union of which the 

 same could not be said. R. B. 



Streatham, London, Eng., April 30. 



Geography-teaching. 



The article by Inspector Jolly, on ' Realistic and 

 dramatic methods in teaching geography,' to which 

 you refer in your number of May 12, is without doiibt 

 a clear and full statement of the various points of 

 weakness in such work, and of the remedies to be 

 applied. 



He urges a greater use of material and a more 

 rational and scientific method. On these two jDOints 

 hangs the whole matter. Every one who has ever 

 taught geography knows that nothing can be done 

 without an abundance of aids in the way of objects, 

 pictures, models, globes, maps, etc. ; and every one 

 who has taught in the United States knows that ob- 

 jects, pictures, models, globes, and good maps are 

 there very, very few. 



A full assortment is not found in one single school; 

 a good assortment, only in a small number, where 

 men of wide views have had charge. There are two 

 reasons for this condition of things, — one, that few 

 schools take enough interest in the subject to pro- 

 cure what material can easily be had; the other, 



