SCIENCE— ADVERTISEMENTS 



*TheBock=Benedicr' 



colorimeter, as devised by Dr. Joseph C. Bock 

 and Dr. Stanley R. Benedict of the Department 

 of Chemistry, Cornell University Medical Col- 

 lege, New York, and fully described in the 

 August number of the Journal of Biological 

 Chemistry, 1918, a highly accurate and inex- 

 pensive plunger type colorimeter, having fused 

 cups, plungers and cells, which will resist acids 

 and alkalies. 



The instrument complete, ready for work, 

 with plunger, cup for the unknown and one 

 cell for the standard, (choice of 8 x 10 mm., or 

 15x20 mm. cell - - - - f40.00 

 Extra plungers, each _ _ _ 1.15 



Extra cups - - - - - 1.15 



Extra cells, 8x10 mm. or 15x20 mm., each 2.30 



Guaranteed accurate standard solutions and 

 reagents for the estimation of urea, uric acid, 

 creatinine, and blood sugar, made up in the 

 proper strengths to be used in conjunction with 

 the Bock-Benedict, Kober, Duboscq and V. C. 

 Meyers colorimeters are supplied by us. Ask for 

 our list on complete outfit for chemical blood 

 analysis. 



C. n. SORENSEN CO., Inc. 



Dept. K 

 177 East 87th Street New York 



Every Practicing Chemist Should Have 



Patterson's Qerman=English Dictionary for Chemists 



By AUSTIN M. PATTERSON, Ph.D.. Editor of Chemical Terms for Webster's 

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332 pages. 5 by 7. Flexible binding. $2.50 net. 



Quantitative Analysis 



Fifth Edition, Total issue ! 9,000. Being Volume II of Analytical Chemistry. 

 By the late F. P. TREADWELL, Ph.D.. Transacted by WILLIAM T. HALL, 

 Associate Professor of Chemistry, Massachusetts Institute of Technology. 



This new edition contains a number of methods which have never been in the original German 

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xi-l-940^pages. 6 by 9. 126^gures. CIoth,;$3.00 net 



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