120 



redissolved with higher temperatures. In the past summer some ditficulty 

 was experienced with it in preservinj? larger tishes in warm weather. 

 A sample of the formalin was submitted to Dr. Palmer, Professor of 

 Clieniistry in the University of Illinois, for examination. The following is 

 his report on it: "We rtnd that it contains 38^1. per cent, of formic alde- 

 hyde. This is practically the quantity that is supposed to be contained in 

 commercial formalin, i. e., 40 per cent, formic aldehyde. 1 tind that nearly 

 one-half of the formic aldehyde is polymerized, i. e., about 18% per cent. 

 is in the form of the polymer tri-oxyniethylene. I am not sufficiently 

 familiar with the use of the formalin as a preservative to be able to 

 state whether this polymerization will interfere with the use of the 

 formalin as a preservative, but would suggest that possibly the formalin 

 has proved unserviceable because nearly half of the constituent which 

 is expected to do the work is in the form of the polymer, and probably 

 unserviceable." 



Notes on the Examination of A-^egetaele Powders. 



By John S. Wright, 



[Abstract.! 

 Brief accounts were given of the methods employed in preparing 

 vegetable powders for microscopical studies, especially through the use 

 of clearing and other microchemical reagents. References were made 

 to the work previously done along this line and to the literature of the 

 subject. Histological characters of vegetable powders were discussed, 

 particular attention being paid to the value of the microscope as a means 

 of identifying and detecting adulterations in granulated and powdered 

 drugs and spices. 



The Staining op Vegetable Powders. 

 By John S. Wright. 



[Abstract.! 

 The use of differential stains to aid in the study of the histological 

 elements of vegetable powders is in many instances important. If in 



