Operations used in .Quantitative Analysis [2 



Fig. i represents a box of gram weights, which are arranged 

 in the following order : 



Of these, the six smallest platinum weights are not as a 

 rule used, their place being taken by one of the weights in the 

 third column. These are known as ' riders ' (paragraph 3). 



Box of Weights 



In a laboratory where the balance is in constant use it is a 

 very convenient plan to keep the weights most commonly used 

 on a piece of cardboard, just inside the balance case. The 



