I 



MAINE AGRICUIvTURAI, EXPI;RIME;nT STATION. 8l 



are listed as follows by a reputable chemical house. These are 

 retail prices. 



Acid Carbolic, Crude, per gallon 25c. 



Acid Carbolic, Crude 50-60 per cent., per gallon ^^oc. 

 Acid Carbolic, Crude 90-95 per cent., per gallon 50c. 



To get the proper results only the QO-q^ per cent, should be 

 used for making lice poivder. The weaker acids are ineffective. 



Owing to the difficulty in getting the strong crude carbolic 

 acid locally in this State at reasonable prices, the Station has 

 experimented to see whether some other more readily obtainable 

 substance could not be substituted for it. It has been found that 

 cresol gives as good results as the highest grade crude carbolic. 



The directions for making the powder are, therefore, modified 

 as follows : 



Take 5 parts of gasoline, and 



I part of crude carbolic acid, po-pj per cent, strength, 

 or, if the po-pf^ per cent, strength crude carbolic acid cannot be 

 obtained take 



J parts of gasoline and 

 I part of cresol. 



Mix these together and add gradually with thorough stirring, 

 enough plaster of paris to take up all the moisture. As a gen- 

 eral rule it will take about 4 quarts of plaster of paris to i quart 

 of the liquid. The exact amount, however, must be determined 

 by the condition of the powder in each case. The liquid and 

 dry plaster should be thoroughly mixed and stirred so that the 

 liquid will be uniformly distributed through the mass of plaster. 

 When enough plaster has been added the resulting mixture 

 should be a dry, pinkish brown powder having a fairly strong 

 carbolic odor and a rather less pronounced gasoline odor. The 

 powder may be passed repeatedly through a sieve to aid in the 

 mixing. 



Do not use more plaster in mixing than is necessary to blot 

 up the liquid. This powder is to be worked into the feathers 

 of the birds affected with vermin. The bulk of the application 

 should be in the fluff around the vent and on the ventral side 

 of the body and in the fluff under the wings. Its efficiency, 

 which is greater than that of any other lice powder known to 



