TOXIC ACTION OF CERTAIN GASES. 7 
Inasmuch as the check on soy beans was poor, the results in this 
case mar be ignored. 
Arsine does not prevent the growth of Fusarium, Ascochyta, or 
Colletotrichum exposed to it in concentrations up to and including 
3 per cent for 60 minutes. It is of no value as a fungicide. 
CYANOGEN CHLORID. 
Cyanogen chlorid (CNCl), molecular weight 61.47, has a liquid 
density of 1.186 at 20° C. under its own pressure. Its boiling point 
is 15° C. The vapor pressure at 20° C. is 1,002 mm. of mercury. 
It is colorless, has an odor somewhat similar to that of hydrocyanic 
acid, and produces a violent lachrymosal effect. One volume of 
water dissolves 25 volumes of the gas. Cyanogen chlorid is less 
dangerous to human beings than hydrocyanic acid, because it can 
be detected when present in very low concentrations, while its 
presence in higher concentrations is unbearable because of its lach- 
rymosal effect. Plant life is injuriously affected by cyanogen chlorid. 
The concentration was determined in the same manner as was that of 
phosgene. Concentrations of from 0.1 to 4 per cent and exposures 
of from seven minutes to two hours were tried on insects. Fungi 
and seeds were exposed for longer periods. 
The minimum lethal dose of cyanogen chlorid, as compared with 
that of hydrocyanic acid, is given in Table 5. 
TABLE 5.— Relative insecticidal action of cyanogen chlorid and hydrocyanic acid. 
Cyanogen chlorid (100 per cent | Hydrocyanic acid (100 per cent 
lethal). lethal). Z 
Insects. Con- | Time | Tem- | Rela- | Con- | Time | Tem- | Rela- 
ceutra-| ofex- | pera- |tivehu-| centra-| ofex- | pera- |tive hu- 
tion. |posure.| ture. |midity.| tion. |posure.| ture. |midity. 
IPS (i Min. (6% P.ct. | Min oH 
Ants (Monomorium pharaonis L.)-..-- 0.2 30 26 40 10.2 25 40 
Aphids ( Myzus persicae Suiz.).......- Sal 30 26 40 -2 60 24 40 
Bedbugs ( Cimer lectularius L.)-. 1.0 30 27 40 2.0 30 27 40 
Bedbug Ces lectularius L.) eggs... 1.0 60 28 AQ iS eee sos ee oe cans | Sate coonl eee eee 
Beetle, Colorado potato (Leptino- 
tarsa decemlineata SER 2 BSuGE ese ae 5 30 28 40 5 15 30 40 
Beetle, Colorado potato (Leptinotarsa 
decemlineata Say.) larve.-.--.--.----- 5 15 30 40 5 15 30 40 
Beetles, Flat grain (Laemophilaeus 
TMUNUTUS OUND) cae ane st ce os eins scee 5 120 31 40 1.0 60 26 40 
Beetles, Potatoflea ( Epitriz cucumeris 
HT AELIS) oe eee aac = Ie cia sie nene 5 15 27 40 5 7 27 40 
Beetles, Sawtooth grain (Silvanus sur- 
SNNETILETISIS Ail.) ete owe ae soe once Soe 1.0 60 27 40 1.0 30 28 40 
Borers, Grain (Rhizopertha dominica | 
oh ee ee ee 1.0 60 23 40| 1.0 30 30 40 
WSR eer as cee ce mncices casece siscics | 1 15 25 40 3.1 7 25 40 
Bplyelenvesees ese Se eae es cae cis ce ins 5 15 24 40 of 30 25 40 
Fly White (Aleyrodes vaporariorum 
RSENS aoe 2 7 29 40} 3.1 7 30 40 
Mites | Pee ee bamboo ( Tarson- 
tS eee ae eee ee ee 2 30 29 40 2 60 24 40 
Rosthes (Riatiella germanica L.)....-- 5 30 25 40 2 15 25 40 
Roach (Blattella germanice L.) egg 
OMS eee e eet cae etiat ees wee 2.0 60 23 AD |; Sue c vce scawsces soeetee sl Mocewecs 
Spiders. Red (Tetranychus bimaculatus 
LELERIZON A eae See Oe Sa Se Seeeee Coe 5 15 28 40 2 30 23 40 
Weevils,. Flour ( Tribolium ferrugine- 
TDA DADS ae oc ee Ore Ge eEEeSOeeeoe 2.0 60 24 40 1.0 30 34 40 
Weevils, Rice ( Calandra oryzae L.).. 44.0 120 27 40 4.0 120 28 40 
! Tetramorium SERS Fab., and Lasius niger L., var. americanus Emery. 
2 Musca domestica L. 
3 Not minimum lethal treatment. 
496 per cent killed. 
