SCIENCE—SUPPLEMENT 



chemic-al reducing properties. It seems to Iiave 

 no effect upon rubber in the dilution used ; at 

 least, I have never had to replace my rubber hose 

 connections. There are no objections to glucose 

 at all that I have found and dts inexpensiveness 

 and the freedom from the annoyance of constant- 

 ly having to replace a volatile solvent such as 

 alcohol are unquestioned advantages." 



FUMIGATING GAS WAVES ITS OWN RED 

 LANTERN 



A NEW fumigating gas which saves human lives 

 by giving ivarning of its presence has been de- 

 veloped by the U. S. PubUc Health Service in 

 cooperation with the Chemieal Wai-fare Service of 

 the War Department, it is announced by a board 

 appointed to (investigate ship fumigation. It will 

 be used in ridding ships, cars and houses of rats, 

 bedbugs, lice and other insects. 



Hydrocyanic acid gas, the fumigant now used, 

 has occasionally cost human lives because of lack 

 of odor, although by killing disease-carrT,-ing ver- 

 min it has prevented serious epidemics from 

 sweeping over the country. 



The weeping is done by the potential victim, 

 not by his relatSves, when the new gas is used, the 

 expert explained. Cyanogen chloride, a very ac- 

 tive tear gas and a by-product of war work, is 

 mi.xed with the hydrocyanic acid gas to form the 

 new combination for fumigating use. The new 

 poison is easily detected as doses too weak to de- 

 liver a knockout produce severe weeping. It is 

 harmless to foods, tobacco, fabrics, leather, and 

 has no corrosive action on metals that may be on 

 board. The gas does its work quickly and then 

 dissipates rapidly. It costs but little more than 

 the fumigants which are more dangerous to 

 handle. 



Hydrocyanic acid gas and sulphur dioxide are 

 the gases which have been used largely in ship 

 fumigation, the board's report explained. Sulphur 

 dioxide, although it glives warning of its presence 

 in time to allow the escape of any person within 

 the quarters where it is used, is costly, harmful 

 to clothing and foodstuffs, and requires from 5 to 

 12 hours exposure. Hydrocyanic acid gas is 

 cheaper and more poisonous than the sulphur di- 

 oxide and does not affect food, clothing, or other 

 articles. But it is odorless and non-irritating 

 and leads to fatalities due to failure to detect its 

 presence in time. 



COMBINED DYES KILL BACTERIA 



' ' Dye bacteria and they die ' ' is one way of 

 expressing a discovery that Professor John W. 



Churcliman, of Tale University, and surgeon-in- 

 chief of the New Haven Hospital, has reported to 

 the National Academy of Sciences. 



' ' Different kinds of aniline dj'es have high bac- 

 tericidal power," Dr. Churchman said. "By mix- 

 ing two kinds of dyes of opposite selective power 

 a mixture results that readily kills all bacteria. 

 The two dj'es may be used together in a mixture 

 of this kind, and the strength of one fortifies the 

 weakness of the other. This establishes a new 

 principle in dye therapeutics." 



In 1912 Dr. Churchman discovered that the dye, 

 called gentian violet, kills certain kinds of bac- 

 teria even when it is as w-eak as one part in a 

 million. This fact was applied in treating many 

 kinds of infections. 



Now Dr. Churchman has announced the finding 

 of another aniline dye, acid fuchsin, which kills 

 the bacteria which the gentian violet spares and 

 spares those which the gentian violet kills. The 

 mixture of the two dyes, which has a royal purple 

 color, spares none of the bacteria. 



' ' Contrary to what is usually held, dyes may be 

 effective against bacteria even though they do 

 not stain them, ' ' he said. ' ' Bacteria may also 

 be stained by dyes without injurj'. ' ' 



He has shown, moreover, that the mechanism by 

 which dyes ' ' kill ' ' bacteria depends not on their 

 ability really to kill them, but to paralyze tlieir 

 reproductive capacity. 



ITEMS 



An American, AVilliam Wlieelwright, introduced 

 the telegi-aphic system into Chili, and organized 

 tlie first steamship service between the west coast 

 of South America and Europe. 



'Many rice crops of the South to-day are di- 

 rectly descended from a pocketful of rice 

 smuggled out of Italy by Thomas Jefferson. 



Thomas Jefferson, author of the Declaration 

 of Independence, and third president of the United 

 States, was also an astronomer, physicist, en- 

 gineer, anatomist, geologist, zoologist, botanist 

 and paleontologlist. 



Leonardo da Vinci, famous painter of the 

 woman with the million-dollar smile, was the best 

 physiologist of his time and made anatomical 

 drawing of human bodies which he dissected with 

 lals own hands. 



The United States imported 43,365,763 bunches 

 of bananas in 1921, but this fruit was once sold 

 in this country as a tropical curiosity at ten cents 

 apiece with each individual banana wrapped in 

 tin foil. 



