October 26, 1888.] 



SCIENCE 



197 



"As connected with this general subject," continues Mr. Osborn, 

 " I would call to mind the investigations of Mr. Thomas Gaffield 

 of Boston, who established conclusively, more than twenty years 

 ago, the slow effect of light on colorless glass in gradually giving it 

 color, sometimes pinkish and sometimes yellow, the former being 

 apparently due to a re-o.\idation of the reduced manganese em- 

 ployed to counteract the iron. These changes often require years 

 for their completion. 



" Experiments only just completed tend to show that pure cellu- 

 lose in the form of the finest filtering-paper is not sensitive to light; 

 at least, a constant exposure in a horizontal position to diffused and 

 direct sunlight failed in two weeks to produce any perceptible 

 change in color. On the other hand, the same filtering-paper col- 

 ored with picric acid, and similarly exposed for the same time 

 (about one hundred and forty hours of diffused and direct sunlight), 

 gave a coloration as before, when sized and calendered paper of 

 the best quality was treated with the acid. 



" Simultaneously with the above exposures, another was made of 

 the same duration and in the same way. This was the presentation 

 of a thin stratum of commercial picric acid on glass to the same 

 illumination as that already mentioned, under a stencil tinfoil neg- 

 ative and a plate of glass covering the same. The picric acid was 

 darkened, as before, very decidedly, though it would be difficult to 

 exhibit the results in a satisfactory way by means of a specimen." 



Yellow-Fever and Bad Sanitation. 



Surgeon-General Hamilton has just published the reports of 

 several of the government inspectors who were detailed to visit the 

 cities and towns of Florida, and ascertain their sanitary condition and 

 whether yellow-fever prevailed in them or not. Among these re- 

 ports is that of Dr. J. L. Posey upon his visit to Macclenny, a small 

 town, of about six hundred inhabitants, in Baker County, in which 

 the fever was epidemic. Here is what he says about the sanitary 

 ■condition of the place : — 



" The general appearance of the town, which consists of perhaps 

 a hundred stores and dwellings scattered over a rather large area, 

 indicated a very wretched sanitary condition. The streets along 

 the railroad-track, as well as others, were covered with heaps of 

 decaying sawdust, and garbage of every description spread over 

 them, drains obstructed, and open lots overgrown with weeds and 

 rank vegetation. The floors and platforms of the depot-buildings, 

 passenger and telegraph offices, and their vicinity, were covered 

 with lime, which had recently been thrown broadcast. A further 

 stroll through the town revealed a similar deplorable sanitary state, 

 — the steps and front galleries, and porches and premises, of resi- 

 dences, lavishly sprinkled with lime, and the yards filled with ac- 

 cumulated garbage. No organized measures had been adopted by 

 the local health authorities to even ameliorate, much less ^correct, 

 this unsanitary state of their town. 



" The site of the town is a low, flat, sandy plateau, without suffi- 

 cient elevation to give effective drainage ; the surrounding pine- 

 forests being interspersed with a series of marshes and alluvial 

 basins. No attention had been given to the removal of excreta or 

 their proper disinfection. The water-supply is generally obtained 

 from wells at a depth of fifteen or twenty feet, and is of a quality 

 which I consider very unwholesome, having experienced personally 

 its disagreeable effects. The atmospheric condition resulting from 

 such foul surroundings was fully prepared to propagate the in- 

 fectious material, which had been already introduced into the town, 

 and had been gradually developing since the ist of August. 



" I went from house to house, and found the sick and dying hud- 

 dled together in small rooms, with windows and doors closed, the 

 floors sprinkled with chloride of lime, carbolic acid, and a variety 

 of other disinfectants. The oppressive odor of disinfectants min- 

 gling with the close atmosphere of the sick-rooms, laden with the 

 emanations from the excreta and ejecta of the patients, together 

 with the dreadful visages of the dying, was shocking to every sense, 

 and the scene well calculated to appall the stoutest hearts. I have 

 ■seldom witnessed a more pitiable and melancholy sight than that 

 presented to my view in my house-to-house inspection through this 

 desolate scourge-swept town. As I returned to the hotel in the 

 evening, I met many whose pale, wan features, languid air, and 

 step marked them as convalescents from the disease, and others 



who, with anxious look, approached me, and in whispered tones 

 asked to know my opinion of the prevailing fever. I told them that 

 they must escape with the rising sun, or, remaining, fall victims to 

 yellow-fever. 



" A late report shows that there have been 189 cases out of an 

 actual population remaining of 195, the deaths being 21 whites. 

 Of the above number, 160 were whites and 29 colored. There are 

 now sick 1 1 white and 8 colored." 



Dr. Posey himself contracted the yellow-fever at Macclenny, but 

 has since recovered. 



Comment upon such a report as this is unnecessary. Yellow- 

 fever is a disease that seeks filth and bad sanitary conditions, and, 

 wherever it finds these and an unacclimated population, it is cer- 

 tain to become epidemic. Its whole history in this country proves 

 this ; and especially was this illustrated in the terrible experiences 

 of Galveston about twenty years ago, of Shreveport a few years 

 later, and, more recently, of Memphis. Yellow-fever never became 

 epidemic where the sanitary conditions were good, although the 

 germs of the disease have frequently been introduced into them. 

 It is probable that the sanitation of Jacksonville is much better 

 than that of the cities named was at the time the scourge swept 

 over them ; and this, it is believed, accounts for the mild form of 

 the fever there, and the low rate of mortality. 



The Human Heart an Electrical Battery. 



The discovery announced in the following brief notice has greatly 

 interested the scientific men of Washington, who are looking for 

 fuller reports in the British scientific journals. This brief article 

 appeared in the Pall Mall Budget of Oct. 4. 



" The most important of the inaugural addresses at the hospitals 

 was Dr. Waller's at St. Mary's, on his discovery of electrical cur- 

 rents caused by the pulsation of the human heart. The researches 

 which Dr. Waller described have occupied him during the last four 

 years ; and the record was interesting, he thought, as an actual ex- 

 ample of what goes on in physiological laboratories, and correction 

 of ' that most unfortunate and mischievous error that they are 

 chambers of horrors.' But more interesting still are the results of 

 the researches themselves ; for if in each human heart there be in- 

 deed an electrical battery, then developments in the art of electricity 

 may in time become possible, beside which Mr. Edison's wonder- 

 land will seem commonplace." 



Derelicts on the Ocean. 



One of the most interesting subjects to be discussed by the In- 

 ternational Marine Conference in Washington next spring will be 

 " the destruction, or at least the frequent reporting, of dangerous 

 derelicts." The fullest and most valuable information in regard to 

 drifting wrecks, their courses and location, now furnished anywhere, 

 is given on the monthly Pilot Chart issued by the United States 

 Hydrographic Office. Numerous reports are received daily from 

 the captains of vessels ; and when the latest facts are plotted, and 

 represented graphically upon the chart, captains of vessels leaving 

 port are able to see at a glance just about where on their voyages 

 they may expect to encounter these dangerous obstructions. 



When one of these derelicts drifts into the path followed by 

 many vessels, the danger is greatly increased, and remains until the 

 wreck breaks up or drifts into unfrequented parts of the ocean. 

 The Pilot Chart for October shows the very interesting history of 

 the derelict schooner, ' W. L. White.' She was wrecked off the 

 Delaware capes in the great March blizzard, first drifted south and 

 then north-east, and by the last of March was found in the track 

 of the transatlantic steamers, where she remained six months, drifting 

 slowly north as the summer months went on. and as the steamers 

 changed their tracks to the north. From March 13 to Sept. 19 she 

 was reported thirty-eight times. In twenty-three instances the 

 reporting vessel passed near enough to read her name. On May 30, 

 three vessels ' fell in ' with her ; June 17, two ; and Aug. 7. two. Of 

 the thirty-eight vessels which reported passing her, twenty-eight 

 were transatlantic steamers, and were, no doubt, travelling at high 

 rates of speed when they passed her, and did not see her until she 

 was close by. The awful results of a collision on any one of these 

 occasions can better be imagined than described. 



Icebergs frequently give notice of their near approach by the 



