



I 



INTUMESCENCES, 137 



within three days. The influence of the solution was evi- 

 dently a very caustic one because the injurious effect was 

 made evident within twenty-four hours after the spraying. 

 The leaf tissue was killed throughout its entire thickness, 

 as shown on the upper side of the leaves, where the surface 

 appeared shrunken and discolored. Grape leaves sprayed 

 at the same time with this solution likewise had a browned 

 appearance after twenty-four hours, and in a very few days 

 all of the tissue struck by the spray was killpd. 



A third series of experiments consisted in spraying a 

 number of thrifty cauliflower plants with various solutions 

 of copper salts, without any ammonia addition, and another 

 set of plants with ammonia solution and ammonium car- 

 bonate solution. The plants sprayed were as follows : 



Series No. 1. Sprayed with ammonium copper carbonate, using the 

 same solution as in the previous experiments. 



Series No. 2. Sprayed with copper nitrate solution (15 gr. copper 



nitrate [Cu(N0 3 )2 + 3H 2 0] per litre). 



Series No. 3. Sprayed with copper acetate solution (12 gr. per 



litre). 



Series No. 4. Sprayed with copper chloride solution (10 gr. per 



litre, the copper being equivalent of the amount in Bordeaux mixture). 



Series No. 5. Sprayed with copper sulphate (CuS0 4 + H 2 ; 15 gr. 



per litre). 



The ammonia used was an aqueous solution containing 41.88% total 



ammonia as hydrate. Based upon this determination various strengths 



of solution were made. 



Series No. 6. Were sprayed with 10% ammonia (that is, 4.188% 



actual ammonia). 



Series No. 7. Sprayed with 2% ammonia (that is, .837% actual 



ammonia). 

 ^Series No. 8. Was sprayed with an aqueous solution of ammonium 



carbonate (NH 4 )2C03, 5% solution. 



After four days these plants showed the following con- 

 ditions : 



Series No. 1. Ammonium copper carbonate. Younger sprayed 

 leaves show distinct eruptions on the lower surface, which were strictly 

 , l conflned to the places where the spray struck the surface of the leaf. 

 The eruptions were in every way characteristic intumescences. Where 

 the spray struck the leaf in any quantity the eruptions were in large 

 masses. 



