APPENDIX. 



535 



1445 ( 147). Dropping-bottle Oiler. A bottle of the kind shown in Fig. 129, used 

 largely in microscopic work, is found to be a very convenient oiler. The glass tube is pre- 

 pared as directed for glass canulae ( 340), except 

 that its large end is slightly flared while hot by 

 pressing it upon some blunt, pointed object. 

 The bulb is a pure rubber nipple. 



1446 ( 251, A). Liquid Gelatin. The 

 liquid gelatin referred to is prepared as follows : 

 75 grams of the best translucent glue is put into 

 a clean towel and crushed with a hammer. It 

 is then placed in a fruit jar and 100 cc. of com- 

 mercial acetic acid poured over it. After stand- 

 ing three days or more in a warm place, there 

 should be added 100 cc. of water and 100 cc. of 

 95 per cent, alcohol. This preparation will re- 

 main liquid at the ordinary temperature of a 

 sitting room (20 C.). It should be of such a con- 

 sistency that when spread upon ordinary note 

 paper it will dry on the surface without pene- 

 trating the paper. If too thick, it may be thinned 

 by adding the liquids in the proportion given 

 above, or it may be thickened by adding glue. 

 This liquid glue or gelatin may be used like 

 common mucilage. Both are sometimes im- 

 proved by mixing them. The brush used must 

 be mounted in quill or something that will not 

 rust. A quill duster, with the addition of a 

 wooden handle, answers very well. 



1447 ( 264). Obtaining Alcohol Free of 

 Tax. (A) The original bill granted the privi- 

 lege only to incorporated or chartered institu- 

 tions ; later provisions apply to all educational 

 institutions. 



(B) In the application and the bond, the first name of each person named must be 

 written in full or an unmistakable abbreviation must be given. 



(C) The bond must be executed for a sum equal to double the amount of tax due upon 

 the alcohol withdrawn. 



1448 ( 333, A). To Dry Jars Quickly without Heat. Clean them properly, rinse 

 them with rain (or distilled) water, and let this drain off. Then rinse with strong alcohol 

 and finally with ether. The evaporation of the latter will leave the surface perfectly dry. 

 Recommended by F. Lenggenhager in the Druggists' and Chemists' Circular. 



1449 ( 336). Soluble Berlin Blue. This form of Berlin blue is used largely in 

 making fine injections and many experiments. Directions for preparing it are given in 

 nearly all the modern works on Microscopy, and, being so widely used, it has become 

 an article of commerce, and may be had of most dealers in microscopic materials. It 

 should be obtained in the solid form and a saturated solution prepared with distilled or 

 rain water. Such a solution may be used for a cold-flowing injecting mass ( 1087), or it 

 may be mixed with glue as directed immediately below. 



1450. Blue Gelatin for Injections. To prepare this, soak fine glue in clean cold 

 water until it becomes soft ; then transfer it to a metal dish and heat over a water bath 



FlG. 129. DROPPING-BOTTLE OlLEK, 



WITH DROPPING TUBE REMOVED ; 

 x.5. 



