160 EXPERIMENT STATION. [Jan. 



crally cousidered tliat the older a lettuce soil, the better it is for 

 this crop, hut if commercial fertilizers are employed indiscrimi- 

 nately in a lettuce house already well supplied with plant food, 

 the chances are that a case of malnutrition will result. 



Roses, carnations and violets require a rich soil, and a con- 

 siderable amount of manure is used by floriculturists in their 

 soil. Cases of malnutrition are prevented here by never grow- 

 ing these crops in the same soil more than one year, the benches 

 being refilled Avith fresh soil each year. A typical rose soil is 

 composed of one-third loam, one-third pulverized sod and one- 

 third cow manure. In addition to this, the plants are watered 

 once a week with a strong liquid manure. Cases of malnutri- 

 tion with this treatment seldom if ever occur with roses. 



A few years ago an experiment was conducted in one of our 

 houses devoted exclusively to the growing of American Beauty 

 roses. The soil was prepared as described above, and liquid 

 manure was applied freely once a week or oftener. The first 

 year the roses did well, and for the jDurpose of experiment Ave 

 attempted to grow a ncAV crop of roses in the same soil which 

 had been used the previous year. The soil was partially ren- 

 ovated by the addition of new sod and some cow manure, and 

 besides this it received its customary application of liquid cow 

 manure. The plants had not been in the soil many weeks, how- 

 ever, before they commenced to die, and it was not unusual for 

 a number to die in a single week. The results of this experi- 

 ment were only what was expected, but a careful examination of 

 the plants was made which showed them to be free from patho- 

 genic organisms. The roots, however, were in a bad state, their 

 condition showing plainly what was the matter. Since it Avas 

 thought that this experiment had then proceeded far enough, 

 we decided to flood the beds with water, and make analyses of 

 the percolate Avhich came through the bottom of the beds. The 

 beds were flooded for tAvo hours each, and the water that came 

 through first Avas, as might naturally be expected, highly colored, 

 Avhile that Avhich came throngh later Avas clearer. The last 

 percolate, after two hours' drenching, Avas remarkably clear. 

 Samples of this Avater Avere collected at intervals of every fifteen 

 minutes, and chemical tests for acids and other substances were 

 made. The results of the analj^ses Avere quite surprising, and 



