SCIENCE 



[N.S. Vol. XXXI. No. 



15" 15"", Pae. St. time, on the night of September 

 1, 1909, and after the first observation the relative 

 humidity was found not to exceed 4 per cent., the 

 vapor tension not to exceed 0.15 millimeter at 

 any of these readings. 



My statement quoted in Lowell Observatory 

 Supplement refers to the weather in general dur- 

 ing our stay on Mt. Whitney, but referring to the 

 weather on September 1 and 2, Professor Camp- 

 bell states : " No clouds were visible in any part 

 of the sky on either night. There had been a few 

 clouds in the afternoons, but these cleared away 

 completely at sunset. There were no clouds in 

 the forenoon of September 3. We can not doubt 

 the evidence of the clouds and the instruments 

 that considerable moisture existed in the after- 

 noons and early evenings, and that later in the 

 evenings the vapor contents of the air were re- 

 duced to a remarkably low quantity." 



I was present, and saw all the spectra, and 

 can confirm Professor Campbell's description of 

 them, and also his statement of the apparent 

 condition of the sky during his observations. I 

 also verified the excellence of definition of his 

 spectroscope. If, as stated in the Lowell Observa- 

 tory Supplement above referred to, " The excessive 

 moisture must have pervaded the air generally to 

 the masking of moisture on Mars," it could not, 

 in my judgment, have failed to have produced a 

 little a band of more noticeable strength both for 

 Mars and the moon in spectrograms No. 1 and 

 No. 2. 



As of course you would not wish me to be 

 placed by a bulletin of the Lowell Observatory 

 in what I regard as a false light, I venture to 

 hope you will do me the great favor to publish 

 this letter completely. 



By authority of the secretary: 



Very respectfully yours, 



C. G. Abbot, 

 Director, Astrophysical Observatory 

 Director Percival Lowell, 



Lowell Observatory, 

 Flagstaft', Arizona. 



53 State Street, Boston, 



16 May, 1910. 

 Dear Sir: On my return from Europe to-day 

 I find your note of March the twenty-fourth. 



I am very sorry that you should feel hurt by 

 a quotation of your own words, nor does it seem 

 to me that your letter changes them in the least. 



and as to publishing the letters it receives, this 

 is never done by the observatory. 

 Believe me to be. 



Yours truly, 



Peecival Lowell, 



Director 

 Professor C. G. Abbot, 



Director, Astrophysical Observatory, 

 Washington, D. C. 



/' BACTERIA IN THE TROPICS 



v To THE Editor op Science : Allow me to 

 correct a statement made on page 618 in no. 

 799 of Science. It reads : "As a matter of 

 fact, the ordinary bacteria of northern lati- 

 tudes do not flourish in the tropics." 



During the summers of 1907 and 1909 I 

 had ample occasion, as physiologist of the 

 U. S. Experiment Station in Mayaguez, Porto 

 Eico, to examine soils in this tropical island. 

 I found that the most common soil microbes 

 of the north occur also there. Bacillus my- 

 coides takes here as there the most prominent 

 position, then follows Bacillus suMilis and 

 Bacillus hutyricus (Clostridium) and then 

 B. fluoresceiis liquefaciens. Azotohacter is 

 found everywhere on the surface in great 

 abundance. A superabundance of microbes 

 in these tropical soils is checked by a very 

 rich infusorial life. Infusoria, Flagellata 

 and Amoebffi devour continuously great num- 

 bers of microbes. The nitrogen content of the 

 superficial soil-layers is doubtless due to a 

 considerable extent to the dead and living 

 bodies of these low animals. 



Oscar Loew 



QUOTATIONS 



THE salaries OF PROFESSORS 



While the universities of the land are re- 

 ceiving the most munificent gifts, while mil- 

 lions are devoted to the construction of marble 

 halls and ivory towers, the wives of the col- 

 lege professors are trying to make both ends 

 meet on their husbands' average salary of 

 $2,500 a year. The size of some professors' 

 families fails to support the theory of race 

 suicide, but their stipends for training the 

 youth of this great and wealthy country af- 

 ford a pretty clear demonstration of the be- 



