GERMINATION CAPACITY 625 



every 100 lbs. of the seed 97 only are true to name, and of 

 these true seeds only 96 in every 100 will germinate. The 

 number of lbs. of useful seed in every 100 of such a sample is 

 found by multiplying the purity percentage by the germination 

 capacity percentage and dividing by 100. In this case it is 



- — ^=93- 



TOO 



In other words, although in every 100 lbs. of the sample as 

 purchased there are 97 lbs. of true seed, only 93 lbs. of the 

 latter will germinate. The numbers obtained by multiplying the 

 percentage purity by the germination capacity and dividing by 

 100, are directly proportional to the seed which is capable of 

 germination, and indicate the percentage of seeds of real value 

 to the farmer. Moreover these numbers are valuable in that 

 they enable us to compare the relative cheapness or dearness of 

 seed. 



Two samples of perennial rye-grass, A and B respectively, 



were offered by different firms at 2;^d. per lb. The purity of A 



was found to be 96 per cent, and germination capacity 98 per 



cent. ; B.'s purity was 99 per cent, and germination capacity 92 



per cent. The real value of A or the percentage number of true 



. 96 X 98 

 rye-grass seeds capable of germination is = 94 J that of B is 



go X 92 



^^ — ^- = 91. Hence A is the more useful and the cheaper seed 



as in 100 lbs. of it there are 94 lbs. capable of growth, whereas 

 in the purer sample B, only 91 lbs. in every loo are of any 

 value. 



On comparing the real values of seeds as obtained by examina- 

 tion of their purity and germination capacity, it will very often be 

 found that samples offered at a cheap rate per lb., are in reality 

 more expensive than those quoted at higher prices. For example, 

 two samples of meadow foxtail grass, which we will name A and 

 B, are offered at is. sd. and is. 8d. per lb. respectively. The 



2 R 



