PROCEEDINGS OF THE CHEMICAL DEPARTMENT. 167 



ments become obvious, and I am satisfied that, so soon as experi- 

 menters have had practical experience of the economy of time 

 and money, coupled with the precision they offer, that for all 

 ordinary purposes large experiments will be abandoned. 



II.— ON THE COMPOSITION" OF THE BEAN PLANT AT 

 DIFFERENT PERIODS OF ITS GROWTH. 



The researches contained in the following pages form part of 

 an extensive series of inquiries which have occupied my attention 

 for some years, and have for their object the investigation of the 

 different agricultural plants at successive periods of their growth, 

 and of which the results for the turnip and wheat crops have 

 already appeared in the 9th and 10th volumes of the Transac- 

 tions. Such inquiries are necessary to fix some of the great 

 fundamental facts of scientific agriculture. They afford informa- 

 tion regarding the period of active growth, the time when valu- 

 able matters are most rapidly absorbed from the soil and the air, 

 their distribution through the different organs of the plant, and 

 the proportions in which they are contained in it when it has 

 reached maturity. All these are facts from which most import- 

 ant inferences may be drawn as to the time and quantity in 

 which manures should be applied to these crops, and which 

 throw light on many other important practical questions. In the 

 papers already referred to, I have pointed out some of the bear- 

 ings of these inquiries, and it will not be necessary to enter upon 

 their consideration at the present moment; but, as an illustration 

 of the nature of the facts which are brought out, it may be 

 mentioned that the investigation of the wheat crop has shown, 

 that contrary to the received opinion, the active growth of that 

 plant is really confined within a very limited period of time, 

 and indicate the importance of assisting its rapid growth by the 

 application of manures at a somewhat advanced period of the 

 season. 



The bean plants which formed the subject of examination 

 were grown in the year 1864, at Grange, Kilmarnock, on a 

 reddish brown clay loam, of about 12 inches deep, resting on a 

 subsoil of yellow clay, containing many small trap boulders, and 

 having a thin stratum of moss about four feet down. The field 

 bore mangold in 1862, wheat in 1863, and being in a high state 

 of cultivation, no manure of any kind was applied to the bean 

 crop, as it was feared that the straw might be over-luxuriant. 

 The variety of bean used was the common Scotch or " horse " 

 bean, and they were sown on the 21st April. During the early 

 part of the season the plants made good progress, and gave 



