262 



the planter how he may early in August begin to safely predict from 

 week to week what his jDrobable crop will be early in October. Thus, 

 table on page 259 shows, by the samples taken August "20, that there 

 were then in the beets 3,073 kilograms of suger per hectare, whereas 

 on October 9 there was 5,068. or five-thirds of that present on August 

 20. This factor, five-thirds =1.()T. is. therefore, that by which the 

 figures of August 20 are to be multiplied in order to obtain those of 

 October 9. The following table gives similar factors for the succes- 

 sive decades for the crop of 1879, and when a succession of years has 

 been thus treated we shall know something of the accuracy with which 

 the harvest crop can be predicted. The regularity with which these 

 numbers run shows that after the 1st of September the error of pre- 

 diction can only be a small per cent. 



ICrop fac-! •vrrp;„>,* 

 Date of sampling , 1879). tor for 'of ®'|rr 



'this date. °^ sugar. 



AugustlO 2.74 1,848 



August 20 l.&j 3.073 



AugustSO _ 1.43 I 3,534 



Septeinber9 1.17 ! 4,320 



September 19 __ 1.09 4,655 



September 29 1.08 4,691 



October 9. 1.00 5,068 



Pagnoul calls attention to the fact that the roots contain a consid- 

 erable portion of nitrates, although the soil in which they grow had 

 not received during this or previous years a trace of these salts. 

 This salt could only have come into existence by the nitrification of 

 organic nitrogenous matter, and it is well to insist upon this fact, 

 for we can thus remove from the minds of certain persons the idea 

 that if the beet root contains nitrates they must have been put into 

 the soil by the cultivator. This mistake has frequently caused un- 

 happy contests between the farmer and the sugar manufacturer. 



If the beet root had at its -disposal only a proper proportion of 

 nitrates that had been formed in tlie soil before sowing, these salts 

 would be rapidly absorbed; they would by their decomposition give 

 rise to a large and i)rompt development of leaves, and, consequently, 

 to an easier elaboration of sugar, and in proportion as vegetation 

 advances we should find smaller quantities of nitrates in the beets. 

 This fact was proven by Marie-Davy in 1878. 



If on the contrary the nitrogen is furnished by a process of nitrifi- 

 cation that is prolonged during the ^hole season, then the absorp- 

 tion of the nitrates goes on continuously and their total weight per 

 hectare increases steadily to the end of October, as shown in these 

 analyses for 1879. 



