14 BULLETIN 108, U. S. DEPARTMENT OF AGRICULTURE. 



men. The soils submitted were garden and greenhouse soils, on 

 which the owners had experienced some difficulty in producing vege- 

 tables or flowers. Often the soils had grown good crops, were inten- 

 sively cultivated and heavily manured, and later failed. In this 

 respect the conditions were similar to those on the Mount Vernon 

 soil. This soil had been used for growing flowers and garden plants 

 for a long period of years, had been intensively cultivated and heavily 

 manured for a long time, had failed to show further response to 

 manure, had been declining in productivity, and had been shown to 

 contain salicylic aldehyde in the investigations reported. It seemed 

 profitable therefore to include soils in this examination winch in some 

 degree had a similar history. 



In addition to tins adventitious examination of soil samples a 

 similar survey was made with soils collected in the open field by the 

 field men of this bureau under instructions furnished them. Accord- 

 ingly, samples of field soils were collected from various parts of the 

 United States. A productive sample and an unproductive sample of 

 the same soil type, either from the same field or at least in the same 

 vicinity, were sent in for investigation. The history of the soils as to 

 crops grown, fertilization, drainage, etc., were secured as far as 

 available. 



The results of this examination for the occurrence of aldehyde 

 compounds in soils include good and poor samples from many parts 

 of the United States, comprising acid, neutral, and alkaline soils, 

 soils of different cropping, different texture, origin, drainage condi- 

 tions, climatic conditions, etc. The results of the examination of 

 these soils will now be given. 



A total of 74 soils are described in the two following tables. Of 

 these 14 are garden and greenhouse soils which had failed to grow 

 good crops and 60 are field soils under general farming conditions. 

 Of these 60, 30 were productive soils and 30 unproductive. In this 

 connection attention should again be called to the fact that the field 

 samples were collected in pairs, one good and the other poor, of the 

 same soil type and from the same field or locality, so that statements 

 concerning productivity pertain to the relation existing between the 

 samples of the same type. 



These soils were all subjected to the method described for obtaining 

 aldehyde compounds from soils and the material thus obtained tested 

 with the reagents mentioned. Five of the garden soils and twelve of 

 the field soils gave an appreciable amount of aldehyde compounds 

 when thus extracted, and this material gave positive reactions with 

 the fuchsine reagent and with the ferric chloride. These soils are 

 briefly described in Table IX, together with the results obtained when 

 the material was tested in the manner described with seedling wheat. 



