TOXIC ACTION OF CERTAIN GASES. 5 
Several varieties of seeds were fumigated with phosgene in the 
higher concentrations, the results of which are shown in Table 2 
TABLE 2.— Effect of phosgene on seed germination. 
Germination. 
Exposed 
for 120 
Exposed for 30 min-| minutes 
utes(temp.,27°C.; (temp., 
5 relative humid-| 27° C.; 
Kind of seed. ity, 40). relative 
Check. humidity, 
40). 
2 per cent | 3 percent | 3 percent 
concen- | concen- | concen- 
tration. | tration. | tration. 
Per cent.| Per cent. | Per cent. | Per cent. 
ATIREINBS) STD MRI ERay eI Sees ceo es OS weasel ec PRA ee 81.5 78.5 72.0 82.0 
(Corio, IDerasneas labios 65 soa s5socceubeuecesecanodsesoeseuse 82.5 71.0 69.5 75.0 
Clover Crimsonatoe sau ak el a Gee ie a ae 2 elt 44.0 42.0 30.5 46.5 
Grass, ‘Orchard Pir idees tine Get sh easy ai aa rie Bt ANP gs oad nage att Me el epee Oa 42.5 49.0 Stee 46.5 
Lettuce, Sa) aaa aan cere eek aia aie ane ia ea SNE rl anes 86.5 79.0 66.5 70.5 
NTC ERT KGStameee en ene AIM ne Migs San NEU 59.5 61.5 45.5 19.0 
Muskmelon, VoCksye BOL Geert o it netstat Wa de a Sta 63.5 51.0 3.5 0.0 
Onion, astrahiamibrowner cise h wie Vib m oes heer 52.0 54.5 33.0 51.5 
Radish, EWG Opel C1 Gait a eee ere tt ON Reta Pe oe a 95. 0 91.5 90. 0 93.0 
Wheat, SUI SS TET eee IRI Ty ins ook eA ee 48.5 48. 0 40. 0 20.0 
Muskmelon, millet, and wheat were injured the most. The other 
seeds were not materially affected. In a few cases there seemed to 
be some stimulation. 
Phosgene proved useless as a fungicide against Fusarium, Asco- 
chyta, Penicillium, and Colletotrichum. 
Inasmuch as in cents has no advantage over the fumigants now 
in use and is less efficient, it is not recommended. 
ARSINE. 
Arsine, or arseniuretted hydrogen (AsH;), molecular weight 77.98, 
has a liquid density, under its own pressure, of 1.36 at 20° C. Its 
boiling point is—55° C. The vapor pressure is 8,780 mm. of mercury 
at 10° C. 
Arsine is toxic to human beings, and extremely harmful to live 
plants, in which it produces chlorotic conditions. Metals and glass 
when in contact with the gas become coated with a fine, mirrorlike 
deposit of arsenic. 
The gas was generated by dropping water on magnesium arsenid 
and collecting the arsine over saturated sodium chlorid solution. 
The concentration was determined by absorbing the gas in N/100 
iodin solution and titrating with N/100 sodium thiosulphate solution. 
Concentrations of from 0.5 to 3 per cent, and exposures of from 
seven minutes to two hours were used. The minimum lethal dose 
of arsine for certain periods of time, as compared with that of hydro- 
cyanic acid, is given in Table 3. 
