EOOf-KNOT EELWORai. 107 



"Therefore the only thhig I can recommend is carbohc acid. 

 Potassium cyanide is much too costly; and sodium hyposulphite would 

 be more costly if used strong enough to kill the Eelworm. And I am 

 afraid carbolic acid, although the cheapest remedy I have found, will 

 be far too expensive for the Americans to use. Thirty-three ounces to 

 fifteen cubic feet is equal to GOOO lbs. to the acre, and would cost, for 

 acid alone, about £15. Then, to be effectual, it should be thoroughly 

 mixed with the soil with a fork : I am quite sure ploughing alone would 

 not be sufficient. Then I think it should be used when the soil is 

 moist, and not too cold ; for the object should be to use the acid at 

 the time when the Eelworm is most active. I do not think the strength 

 I mention would kill eggs ; and unless the eggs are quickly brought to 

 life, the strength of the acid would pass away. I have seen Tomato 

 plants nearly die when planted in soil directly after the acid was used 

 and only moderately mixed, but after a week they began to recover, 

 and soon made new roots, and grew as well as the other plants that 

 were in soil where no acid at all was used. 



" I am also very doubtful whether I shall succeed in getting rid of 

 the Eelworm entirely myself. For, four years ago, my Cucumbers 

 having what we called clubbed (and failed, and which I now know was 

 caused by the Eelworm), we drenched the walls and surface of a house 

 with carbolic acid. After, the soil the plants had been grown in was 

 wheeled out. And we used the acid very much stronger than now 

 seems to be necessary. And yet the Cucumbers clubbed and failed in 

 the same way in the following year. 



" In May of this year, I used carbolic acid in various strengths in 

 a house where Cucumbers had grown. The greatest strength being 

 nearly twice as much as the thirty-three ounces to fifteen cubic feet. 

 But we did not plant Tomatoes in the soil until five weeks after using 

 the acid. For a time it seemed as though most of the Eelworm was 

 killed. But now, four months after planting, the Tomatoes are getting 

 quite badly affected. It seems to me that in a greenhouse there are 

 ■so many places in which they can harbour, that it is impossible to get 

 at all. In a field it would be different ; and I have not the slightest 

 doubt but that a dressing of 6000 lbs. of carbolic acid to the acre, used 

 properly, would completely clear the Eelworm. 



" If you care to mention anything I have written in your Eeport, 

 you are quite at liberty to do so, but, please, do not mention niy name 

 in it. If you are writing to Dr. Ritzema Bos, Dr. Neal, or Professor 

 Atkinson, you may give them my name and address; and if they wish 

 to write me for anything, I shall be quite willing to give them any 

 further information I can. 



" I may add, in using the carbolic acid, I always mixed it with 



