Apbil 8, 1887.] 



SCIJEJSfCE. 



331 



conference called by Admiral Mouchez, director 

 of the Paris observatory, for the purpose of form- 

 ing a plan of co-operation in photographing the 

 whole sky. The proposition is to enlist ten or 

 twelve observatories in the undertaking, and to 

 obtain instruments of uniform power, so that their 

 work may be homogeneous. If the suggestion 

 that each plate shall be four degrees square is 

 adopted, about 11,000 plates will be required ; and, 

 with an average of 100 plates per year from eleven 

 observatories, it will take ten years to complete 

 the map. It is understood that Dr. Peters of 

 Clinton, and Mr. Rutherfurd of New York, will 

 also attend the conference. 



A VERY VALUABLE CONTRIBUTION by T. Mitchell 



Prudden, M.D., on bacteria in ice, and their rela- 

 tions to disease, with special reference to the ice- 

 supply of New York City, appears in the Medical 

 record of March 36. In a series of thirty-two biolog- 

 ical analyses of the Croton water, as it is delivered 

 in the city, Dr. Prudden found the lowest number 

 of living bacteria to be 57 to the cubic centimetre ; 

 the highest, 1,950 ; while the average was 243. 

 While it was at one time thought that the pres- 

 ence of a considerable number of living bacteria 

 in a water was evidence of its being unfit for 

 drinking-purposes, we have now learned that this 

 view must be greatly modified. Bacteria are al- 

 most everywhere present, in soil, air, etc., and 

 by far the larger proportion are, so far as we know, 

 perfectly harmless. Their role in nature is to tear 

 down organized bodies into their simpler constitu- 

 ents, a small part of these being used for their 

 own nutrition and growth, while the larger part 

 is given up to other organisms for their life-pur- 

 poses. It still remains true, however, that a cer- 

 tain number of species, which can live in water 

 as well as elsewhere, can and do produce deadly 

 diseases, and are responsible for some of the 

 most frightful epidemics. 



Dr. Prudden made a series of experiments to 

 test the effect of freezing on the bacteria. His 

 method was as follows: a large number of test-tubes 

 were plugged at the mouth with cotton, and steril- 

 ized. Into these tubes was put sterilized water 

 mixed with a small quantity of a pure cul- 

 ture of some well-defined species of bacteria, the 

 number of bacteria in one cubic centimetre of water 

 having been previously determined. The tubes were 

 then exposed to a temperature of from 14° to 30° F. , 



the water becoming solid in a short time. Six differ- 

 ent species of bacteria were thus experimented with: 

 1°. Bacillus prodigiosus ; 2°. A short bacillus fre- 

 quently found in the Hudson River water, and 

 occasionally in the ice, apparently identical with 

 the Proteus vulgaris of Hauser ; 3°. A slender 

 bacillus very common in Croton water ; 4°. Sta- 

 phylococcus pyogenes aureus, derived from a case 

 of pyaemia ; 5°, A short bacillus very common in 

 ice all about New York, which may be designated 

 the 'fluorescent bacillus,' from its appearance in 

 gelatine ; 6°. The bacillus of typhoid-fever. In 

 the case of the Bacillus prodigiosus, there were 6,300 

 bacteria in a cubic centimetre of water before 

 freezing ; after being frozen 4 days, 2,970 ; after 

 37 days, 23 ; and none after 51 days. Of the 

 Staphylococcus pyogenes aureus, there were a 

 countless number before freezing ; after 18 days 

 of freezing, 324,598 ; after 54 days, 34,330 ; and 

 after 66 da^^s, 49,380: of the typhoid-fever bacil- 

 lus, innumerable before freezing, 1,019,403 after 

 being frozen 11 days, 336,457 after 87 days, 89,796 

 after 43 days, and 7,348 after 103 days. These 

 experiments were repeated with practically the 

 same results, so that it may be accepted as abun- 

 dantly proven, that, after prolonged freezing, a 

 considerable number of the typhoid bacilla remain 

 alive. 



WILLIAM BABCOOK HAZEN. 



The sudden death of Brig. -Gen. William B. 

 Hazen, chief signal officer of the U. S. army, 

 which occurred on Sunday, Jan. 16, 1887, de- 

 prived the country of one of its most distinguished 

 oflicers, and the signal corps of a chief who took 

 a broad view of its duties and relations to the 

 world of business and science. 



Gen. William B. Hazen was the great-grandson 

 of Thomas Hazen, who was born in 1719, and who 

 was himself a great-grandson of Edward Hazen, 

 who emigrated from England before 1649, and 

 settled at Rowley, Mass., where he died in 1683. 



The descendants of Edward Hazen include 

 many names eminent in business, theology, and 

 war. Energy, industry, and strong convictions 

 characterize the members of the family on all 

 sides. 



General Hazen was born at West Hartford, Vt., 

 Sept. 37, 1830. While he was yet a child, his par- 

 ents removed to Hiram, Portage county, O. In 

 1851 he was appointed from Ohio as a cadet to 

 the U. S. military academy at West Point, from 

 which he graduated July 1, 1855. He was assigned 

 to the 8th U. S. infantry, and spent the next five 



