y6o 



mendation as a remedy for chronic gummy exudations is based at least upon 

 self-delusion if not the exigencies of advertising. 



Schweinbez holds the same opinion of the related substances "Tuv", 

 "Dendrin", "Baumschutz", "Neptun". 



7. Lyzol. Formerly lysol had its enthusiastic adherents and doubters 

 just as carbolineum has them now. The Lysolum puriim of Scholke and 

 Mayr in Hamburg, introduced into trade about the end of the 8o's of the 

 last centur)', is a transparent, brown, syrup-like fluid which remains dissolved 

 and perfectly clear in pure water, and has been extensively used as a means 

 of disinfection. In introducing it, it was said that, according to experi- 

 ments, 3g. of lysol to a litre of liquid was enough "to destroy, in 15 to 20 

 minutes, bacteria in all their developmental forms, if suspended in liciuids." 

 We are concerned here witli a solution of tar oils in neutral soap and, 

 indeed, with the light tar oils (cresol), for they volatilize almost entirely 

 between 187 and 200 degrees^ In contrast to other commercial products, 

 like creoline, cresoline, Little's Soluble Phenyle. which, as solutions of resin 

 or fatty soap in tar oil only form emulsions with water and usually give off 

 carburetted hydrogen oil (Ethylene), when diluted, lysol has the advantage, 

 at any rate, of complete solubility in water, but shares with the above 

 preparations an injurious effect on the tissues of plants. It was used in 

 horticulture mostly as a spraying substance for leaf lice, thrip. black fly, and 

 other injurious insects. Otto's- cultural experiments, made soon after the 

 introduction of the substance, showed that 0.5 i)er cent, lysol solution, the 

 one commonly used for disinfection, proves to be a severe poison for plants 

 if added to the soil, even if it does not come directly in contact with the 

 seeds or seedlings. With direct action, even in a much more diluted form, 

 it attacks uncommonly sharply the roots of water cultures. It was used in 

 a 0.25 to 0.5 per cent, solution as a protection against leaf lice. In this, 

 however, it kills only some of the leaf lice, the majority of which die onlv 

 with a 2 per cent, solution; the plants were then so blackened and injured 

 that they could not be considered capable of further life. 



8. Carbolic Acid, Amylocarhol, and Sapocarhol. The amylocarbol is 

 a mixture of soft soap, fusel oil, and pure carljolic acid. Sapocarbol is 

 saponified carbolic acid. 



All substances containing carbolic acid are dangerous and usually 

 directly fatal for plants. In Fleischer's experiments'* with the above prepa- 

 rations, the sapocarbol in one per cent, solution was effective for leaf lice 

 without any injur}- to the leaves from the spraying, with a few exceptions. 

 In dilutions which completely kill the leaf lice, Pinosol and Creolin act injuri- 

 ously since both can only be emulsified in water. The Antinonnin, the 



1 Zpitschr. f. Pflanzenkrankh. 1S91, p. 185. 



- Otto, R., tJber den schadlichen Einflu.ss A'on wasserlgen, im Boden befind- 

 lUhen T-,ysoll()sungen usw. Vorl. Mitt. Zeitschr. f. Pflanzenkrankh. 1892, p. 70ff. 



•■! Fleischer, E., Die Wasch.- und Spritzmittel zur Bekampfung der Blattlause, 

 Blutlause u. ahnlicher Schadlings usw. Zeitsch. f. Pflanzenkrankh. 1S91, p. 325. 



