— 20 — 



At the time that the foregoing tests were made, we were not 

 able to get the proper form of apparatus for Professor Patrick's 

 method. A test of that was made, later, by Mr. Cutter, with fol- 

 lowing results, comparing it both with the gravimetric method 

 and Mr. Cochran's ; the apparatus was received from Professor 

 Patrick himself. 



These last results show what can be done with methods of this 

 kind in the hands of a very experienced analyst. All the deter- 

 minations were done in duplicate, and some were repeated three or 

 four times ; the results thus obtained were in most cases identi- 

 cally the same. All the figures given in both tables are the aver- 

 ages of these repeated determinations where there was any differ- 

 ence to be averaged. The gravimetric method followed was Dr. 

 Babcock's asbestos method.* It was intended to use Adams' 

 paper coil method, but suitable paper could not be conveniently 

 obtained in season. 



Report N. Y. State Experiment Station, 1883, pp. 166 and 169. 



