July 27, 1900.] 



SCIENCE. 



147 



I send you an observation apparently indicat- 

 ing such a change In certain features. The 

 phenomenon was observed independently by 

 three members of the party with which I was 

 connected. 



The accompanying sketch is an outline of the 

 corona drawn by Mrs. Clayton during totality 

 at Wadesboro, N. C, on May 28, 1900. At the 

 beginning of totality the polar streamer marked 

 a in this sketch appeared convex toward the 

 zenith but rapidly flattened and toward the end 

 of totality appeared flat or concave toward the 

 zenith as represented by a' in the smaller 

 sketch. There appeared to be other changes 

 taking place in the corona but these I thought 

 might be explained by more detail becoming 

 apparent as the eye became accustomed to the 

 darkness. 



H. Helm Clayton. 



Blue Hill Meteorological Observatory, 

 July 4, 1900. 



NOTES ON INORGANIC CHEBIISTBY. 

 In the March number of Leopoldina, which 

 is published at Leipzig and is the ofiicial organ 

 of the Kaiserlichen Leopoldinisch-Carolinischen 

 deutschen Akademie der Naturforscher, ap- 

 peared an article by Professor F. Fittica of 

 Marburg, in which he claims by heating amor- 

 phous phosphorus to 200° or lower with am- 

 monium nitrate, to have converted the phos- 

 phorus partially into arsenic. He even assigns 

 to arsenic the formula PNjO and writes the 

 equation for the reaction 



2P + SNH^.NOa = (PN20)203 + 10 H^O -]- SN^. 



Apparently from the relative obscurity of the 

 journal in which the paper was published, these 

 remarkable claims seem to have attracted little 

 notice till quite recently, but in the last Berichte 

 Professor Clemens Winkler of Freiberg takes 

 up the subject and shows that Fittica' s con- 

 clusions rest upon an ' ungeheiiereii Irrthum.'' 

 Most phosphorus contains more or less arsenic — 

 up to 2.64 fo — derived from the sulfuric acid 

 used in its manufacture. That Fittica claims 

 to have converted eight to ten per cent, of 

 phosphorus into arsenic Winkler considers 

 merely an estimate. To prove the matter posi- 

 tively Winkler took a specimen of carefully 

 washed and dried amorphous phosphorus and 

 oxidized it in two gram portions with (1) am- 

 monium nitrate, with (2) dilute nitric acid, 

 with (3) chlorin, and with (4) alkaline hydro- 

 gen peroxid. The percentages of arsenic 

 found in the phosphorus were as follows : 



(1) Oxidation with ammonium nitrate (Fit- 



tica's method) 1.910 % 



(2) Oxidation -with nitric acid 1.925 % 



(3) " " chlorin... 1.920% 



(4) " " hydrogen peroxid 1.920% 



This shows conclusively that all the arsenic 

 obtained by the oxidation of phosphorus by 

 ammonium nitrate was originally present in 

 the phosphorus. 



The closing paragraph of Dr. Winkler's paper 

 is worth quoting entire :* "It must be admitted 

 that this occurrence, the consideration of which 

 I have most unwillingly undertaken, has a very 

 grave background. It almost seems as if of 

 late in the pursuit of inorganic chemistry, there 

 is present a dangerous tendency to enter upon 

 speculations, without paying any attention to 

 that thoroughness which has heretofore charac- 

 terized German research. For the cases multi- 

 ply where it is apparent that the theory has 

 been first formed, and then the efibrt made to 

 find the facts one wishes to find, or where one 

 starts out from what the Leipzig physiologist 

 Czermak calls 'inaccurately observed facts,' 

 and hence soon falls into error. The reason 

 for this is to no small degree to be found in the 

 fact that the art of analysis has sufiered an un- 

 fortunate retrogression. I use the word art in- 

 tentionally, for between analysis and analysis 

 *Ber. d. deutseJi. chm. Gesell. 33: 1696 (1900). 



