DESTRUCTION OF FLY LARVA IN HORSE MANURE. 
ARSENICAL DIP. 
Arsenical dip, which is extensively used in the West and South- 
west to kill ticks on cattle and sheep, was prepared according to the 
directions given in U. 8. Department of Agriculture Farmers’ Bul- 
letin No. 603 (Chapin, 1914). This solution was used in three cage 
experiments, namely, full strength, and diluted 1 to 1 and 1 to 3 
(Table I, Series 67, A, B, and C). 
TasLe I.—Destruction of fly larve in horse manure. Results with arsenrcal dip, para- 
dichlorobenzene, and pyridine; cage experiments at Arlington, Va., 1914. 
Wat tract. 
Ne ater extract 
of bac- 
teria per ao 
Treatment of 8 bushels mites sober J gram | Manure, ie ND 
Series. of manure, using 10 emereeds i aicidall | aamure, total | HCI per | Water- Nas 
gallons of liquid. ee Laat caleu- | nitrogen:| 15966: | solaple | NE& 
jeted to (5 grams | nitrogen. Folin 
Ty ai method 
weight manure) 
Per cent Per cent | Per cent 
of control of total | of total 
Number. | average. | Millions. | Per cent. C.c. nitrogen. | nitrogen 
A | Arsenical dip (strong) . 67 87 1, 648 0. 421 10. 50 33. 63 3.5 
67, B | Arsenical dip (1-1).... 57 89 1, 944 S33 5.75 29. 97 4.4 
C | Arsenical dip (1-3).... 131 74 2, 459 547 6.50 33. 82 Bad 
A | Control (water only). . S2G Uae 1, 636 . 625 6. 40 Pair eyeu| aaa ital 
TOBY Neco s Cho) arc ers sus ES BO eas ocoesae 1, 043 - 463 8.75 41, 25 7.1 
Claas GLOW ENG AE PAIS Ne ose ae 843 337 8. 40 26. 70 4,7 
Control average....... AAT scar ie ne es teres tap tA Na ats oe UG AEN aaah |e le el oe Hal Ue 
78 A | Pyridine, 1-100........ 37 63 634 540 8. 90 31.11 3.0 
“\B | Pyridine, 1-500........ 135 0 798 .540 8. 65 31.11 ay a 
A | Control (water only)... OS UN eem a ale 1, 035 611 9. 90 26. 68 1.9 
SI eee LOE NINE He ie PARA NI al Nee 1, 282 . 639 11.15 36. 93 2.4 
Oil seaees LO a ee ORE SOF Neer reas Me na Ne ee CRA yh | cee chat Weng aN ae DO RA 
Control average....... TR er eee ees ic od hae a | (Area a Mie a uaa 
104 {iB Pyridine, 1-100.-...... 3 99-+- 209 - 470 4,75 28. 72 7.02 
AS | eye ClO Sates Mea MINE 2 99+ 128 . 449 4,50 33. 85 2.45 
106 A | Control (water only)... A489) | Reet) hie 19.6 572 4,25 25.00 2.10 
1B leat CG Loy ary tiara ea dees HOBO Beesbouoes 27.1 561 4.65 26. 02 1.41 
Control average. ...... Oe a space tes andl Orca es aaa i cea eco torts UN He ea peda iW 
A | Para-dichlorobenzene, 
79 % pound to 10 gal- 
lons water.......... 10 93 905 . 793 13.15 36. 07 4.8 
IB} |e ere C6 LO aes a as ar ey a 70 50 502 505 11.65 35. 44 4.6 
(For control see81, A, - 
B, and C, above.) 
A | Para-dichlorobenzene, 
98 1 pound to 10 gal- 
lons water........... 11 OFT ara Raye tee a ay Seal] ihre) [a Sy RS CC LT ec LUE eR I 
Bese eh LO aaa Meee pa 68 CJ Gl es Ua ae ee |, Age ne Ne PR A Pn cs NA 
A | Control (water only). . USS 7p ees te ea 283 . 898 11. 40 25.61 2.34 
E18 Ieeoee Coys 2 eae ed GST eisencn ee 165 . 653 10. 75 24.19 4.13 
CRs Gos asa ee a ee CEN as Aaa alls 157 . 533 8.15 27.39 2.44 
Control average....... BAUCUS ee CUO eC ba ONS BBE GTN UG ON 
The two stronger concentrations killed about 88 per cent of the 
maggots and the 1-3 solution about 75 per cent. 
The weaker 
strengths apparently exerted a slight stimulating action on the 
bacteria, and the full-strength dip showed no bactericidal action in 
this one test. The chemical data showed no marked differences except 
for the increased alkalinity where the dip was applied in full strength, 
and this, no doubt, was due to the sodium carbonate in the dip. 
