56 THE AMERICAN MONTHLY [March, 



cess of making. The method of doing this is a secret zealously guarded 

 by the manufacturers and the Government. Its pui'pose is to prevent 

 counterfeiting. Formerly the fibre was scattered in small fragments 

 irregularly through the paper and was easily imitated by exterior marks. 

 The present method insures a continuous line, generally two, of silk 

 fibre running parallel with the length of the note and so woven into the 

 paper as to leave it visible from either side, and yet far enough from the 

 surface to retain its identifying property so long as the note is in circu- 

 lation. The object is sent as a means of information, the contributor 

 finding many people unfamiliar with this means of identifying counter- 

 feit money. It was adopted by the U. S. Government in i§>8^. — IVm. 

 J. Morrison. 



Technique. 



Sections of Staminate Cone of Scotch Pine. — Contributed from 

 the Botanical Laboratory of the University of Nebraska to show what 

 can be done by the paratfine imbedding process in cutting and mount- 

 ing objects which otherwise would fall to pieces. The preparation was 

 as follows in detail : 



The cone was first put into 35 per cent, alcohol for 13 hours. Then 

 successively 12 hours each in 50 per cent, alcohol, 75 per cent, alcohol, 

 hematoxylon, 90 per cent, alcohol, absolute alcohol, alcohol and tur- 

 pentine, pure turpentine, cold paraffine and turpentine. It was then 

 put into warm paraffine and turpentine for 6 hours, then into melted 

 paraffine (50° to 55°) for 6 hours ; it was then imbedded in the paraffine 

 and cut into ribbons upon a Reichert Thome microtome, the sections 

 being 20,u (3 gV hich) thick. The ribbons wei^e fixed on the slide with 

 white of egg and glycerine. The slide was warmed to melt the paraffine, 

 which was then washed away with turpentine, washed next with abso- 

 lute alcohol, then 90 per cent, alcohol, then water (distilled), then stained 

 with fuchsin about two seconds, next washed with distilled water, 90 

 per cent, alcohol, absolute alcohol and turpentine in succession. Canada 

 balsam in chloroform was then poured over the specimen and the cover- 

 glass laid on. I have given every step taken in the operation. The 

 hematoxylon did not penetrate, hence the staining by fuchsin was neces- 

 sary. — Charles E . Bessey. 



Longitudinal Sections of Head of Blossoms of Marigold. — 

 Sent around as an illustration of the paraffine imbedding of vegetable 

 structure. Two ribbons of sections are on the slide. The method of 

 fixing the sections on the slide was as follows : (a) Slide was coated 

 with collodion by flowing as in wet plate photography ; (b^ after the 

 ribbon of sections was put in place it was wet by means of a delicate 

 brush with a solution of alcohol and ether, which softened the collodion 

 and caused the sections to settle down into the film, and the rapid evap- 

 oration of the solution left them securely fastened ; (c) the paraffine 

 being next melted over a lamp, the slide was flooded with turpentine ; 

 (yd) after which Canada balsam and the cover followed. — T. D. Blscoe. 



Mounting Moulds. — Nearly all the mucedines or moulds, so beau- 

 tiful in nature and tempting to the microscopist, are very shy of hand- 

 ling for preservation. This specimen illustrates about the average degree 

 of success which I attain by the following method : A young plant was 

 selected, laid upon a slide and covered with a bit of thin glass ; just 



