372 



SCIENCE. 



agree with the results obtained by prismatic decomposi- 

 tion ; while the results in the other case do not. We 

 think it would be correct to say that iridescence, does not 

 reveal non-luminous bodies in the same way, nor with the 

 same certitude, as that light reveals them by which they 

 are ordinarily visible. In making this last statement we 

 have in mind the fact that the iridescent surface, in ad- 

 dition to its iridescence, also emits or radiates light in the 

 same manner as ordinary visible bodies ; and that these 

 two facts are not to be confounded in our observations 

 and reasonings. Without pursuing the subject further 

 into details, these are some of the reasons why we think 

 the facts of iridescence are not inconsistent with the main 

 doctrine of this paper. 



We conclude then, by reason of the facts and relations 

 to which we have now called attention, we cannot believe 

 that it is correct to say that non-luminous bodies are seen 

 by reflected light ; and we offer the suggestion that the 

 light by which such bodies are seen should fairly and 

 properly be called radiant light, as manifesting all the 

 essential qualities of such light. 



CORRESPONDENCE. 



[The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. No notice is taken of anonymous communi- 

 cations.] 



To the Editor of " Science." 



In an article on overgrown teeth of Fiber Zibethicus 

 (which b) a singular typographical error is printed Fiber 

 Wibethicus) in "Science" for July 16th, the writer 

 describes a not very uncommon phenomenon among 

 rodents to which I can add an interesting example. 



The inclosed drawing represents a similar case, being 

 a woodchuck (Arctomys monax) ; it will be noticed that 

 one of the upper teeth has grown far enough to form a 

 semicircle while the other upper incisor has described a 

 somewhat larger curve and finally thrust itself through 

 the first and then continued to form a complete circle, as ] 

 will be evident from the figure. This specimen was 

 mounted here (with one other similar but not so extreme 

 a case) and is now in the Museum of Comparative Zoology 

 at Cambridge. F. W. Staebner. 



Julv 20. 1 88 1. . 

 Ward's NATURAL Science ESTABLISHMENT, Rochester, N. Y. 



COMET (c) 1881. 

 To the Editor of " Science." 



The comet discovered by Mr. Schaeberle at Ann 

 Arbor, July 13, promises to become a very interesting 

 object, not only because it will soon be visible to the | 



naked eye, but also because its orbit shows great simi- 

 larity to the great comet of 1337, as may be seen by the 

 following comparison : 



188: (Stone) 1337 (Hind) 1337 (Lanzier) 

 Distance of perihelion from node.. 122 30' 108° 44' 90° 41' 



Longitude of node 98 43 99 6 93 » 



Inclination — 141 35 137 6 139 32 



Logarithm perihelion distance 9-7959 9-97 9.92 



The difference between the orbits of the two comets is 

 perhaps not greater than the uncertainty of that of 1337. 

 The latter was first seen in China on the 26th of June, 

 and afterwards in Europe on the 24th of October. 



Schaeberle's comet has been observed here on a num- 

 ber of mornings, and its increase in brightness has been 

 quite perceptible. This morning the tail was very ap- 

 parent, the sky was very cloudy, or I presume it would 

 have been visible to the naked eye. It ought to be quite 

 plainly visible at any rate before the end of this week. 

 It will be at perihelion and nearest the earth about the 

 20th of August, and will remain at approximately the 

 same distance from us for a week or more. A few days 

 before that time its right ascension will have become 

 equal to the sun, so that when at its greatest brilliancy it 

 will be visible in the evening. While it will undoubtedly 

 become a magnificent object, it will not probably equal 

 the great comet now receding from us. 



Ormond Stone. 



Mt. Lookout, O., July 25. 1881. 



ASTRONOMICAL NOTE. 



Washburn Observatory, University of Wisconsin, ) 

 MADrsoN, Wis., July 17, 1881. \ 



To the Editor of " Science." 



Among the new red stars found here, the following is 

 by far the finest and may be of interest : 

 Anon. 9 mag. R. A. i* 48'" 45 s ; Dec. = + 58° 40'. 2 

 1880.0. Edward S. Holden. 



ADULTERATION OF SUGAR. 



To the Editor of " Science." 



Dear Sir— In the leading editorial of " Science " of 

 June 18, you speak of the different results obtained by 

 Prof. Leeds and myself of examination of commercial 

 sugars and syrups for glucose and grape sugar. I can 

 only take exception to one statement contained therein, 

 i. e., the one which intimates that these different results 

 form the theme of a scientific controversy. Since the 

 reception of your letter I have renewed my inquiries for 

 statistics, and can now say that I do not believe my es- 

 timates of the quantities made in the United States are 

 very wide of the truth. Dealers and manufacturers are 

 extremely reticent on the whole subject, and it is only by 

 hard work and often indirection, that one can get at the 

 truth. In your own city, New York, there is a large es- 

 tablishment for making "New Process Sugar," the 

 Manhattan Refining Company, unless it has lately 

 changed its name. Yet a prominent New York chemist 

 stated publicly, and published over his own signature, 

 that he had made diligent search for this establishment, 

 and it could not be found. At the same time, to my 

 personal knowledge, a western firm had just received a 

 large consignment of " New Process Sugar " from this 

 firm. 



At the Boston meeting of the A. A. A. S., I stated on 

 the strength of this personal knowledge that I believed 

 the Manhattan Company was no myth. This statement 

 was published in the Boston and New York papers, and 

 was seen by the proprietors of the Manhattan Company. 

 They wrote to assure me that I was right in my state- 

 ment, sending me at the same time samples of their 

 different sugar for analysis. 



Within the past year the mixing of sugars has largely 

 increased, and is now carried on in New York, in 

 Buffalo, in Chicago, and at other points. A prominent 



