Journal of Applied Microscopy. 



145 



A Black Finish for Table Tops. 



A satisfactory finish for a laboratory 

 table, especially in Chemistry and Bio- 

 logy, is highly desirable. Where the mi- 

 croscope is used a black surface is ob- 

 viously preferable. It is also desirable 

 to have a finish that can resist the action 

 of the common chemicals which either 

 stain or corrode the ordinary wood tops, 

 otherwise they soon become stained and 

 unsightly in appearance. 



A slate or tile top which answers the 

 above demands is expensive in its origi- 

 nal cost and also as a destroyer of glass- 

 ware, and therefore beyond the reach of 

 many. Wood tops, when painted, oiled, 

 or parafllned, present strongly objection- 

 able features. It is possible, however, to 

 dye wood, by a process resembling the 

 "anilin black method" of commerce, 

 cheaply and extremely satisfactorily. 



Nearly two years ago, in finishing a 

 table for student use in the bacteriolog- 

 ical laboratory of the University of 

 Wisconsin, Prof. Woll, of the Experi- 

 ment station, recommended the process 

 of ebonizing which he had seen in use in 

 several laboratories in Copenhagen, and 

 It is the directions he secured there 

 which are given below. While the table 

 was being treated my attention was 

 called to an article which was written 

 shortly before by Prof. Dr. Julius Wort- 

 mann* describing the method used in 

 Denmark. Prof. Barnes, t in reviewing 

 this article, briefly described the process 

 as used here as well as that used in the 

 Danish laboratories, although both are 

 essentially the same. 



The following solutions are required: 



125 grams of copper sulphate, 

 125 grams of potassium chlorate, 

 1,000 grams of water. 

 Boil until salts are dissolved. 



II. 

 150 grams of anilin hydrochlorate, 

 1,000 of water. 



Or, if more readily procurable, 

 120 grams of anilin oil, 

 180 grams of hydrochloric acid, 

 1,000 grams of water. 



By means of a brush apply two coats 

 of solution No. I while hot, the second 

 coat as soon as the first is dry. Then ap- 

 ply two coats of solution No. II and allow 

 the wood to thoroughly dry. A coat of 

 raw linseed oil is next applied. It is best 

 to use a cloth instead of a brush so as to 

 get only a very thin coat of the oil. The 

 desired amount of polish is now given 

 the wood by rubbing in the oil. In the 

 treatment with the oil the deep black 

 color is partially brought out, although 

 this does not unformly appear until the 



table has been thoroughly washed with 

 hot soap suds. This takes out the 

 superfiuous chemicals. 



The finish thus secured is an ebony 

 black which is permanent and very 

 highly resistant to the action of chemi- 

 cals, such as acids and alkalies, even 

 concentrated sulphuric acid having little 

 or no effect if quickly washed off. 



The anilin dye stains may also be 

 readily removed by the application of 

 some solvent, as alcohol. 



It is not only possible to treat new 

 table tops in this way, but old ones take 

 nearly as good a finish. In this case the 

 old oil or paint is planed off and the 

 surface is treated as new wood. 



The tables in the bacteriological labor- 

 atories here are practically in as good 

 condition to-day, after use by students 

 during two school years, as they were 

 when finished. 



To keep the surface constantly in good 

 condition it is only necessary, after a 

 thorough washing, to rub on a light coat 

 of oil. The expense is trifiing. The cost 

 of both solutions, in the quantities given 

 above, will not be over fifty cents, and 

 this amount will cover at least ten 

 square yards of surface. 



W. D. Frost. 



Instructor in Bacteriology, University 

 of Wisconsin, Madison, Wisconsin. 



*Bot. Zeitung, 54, 326. 

 tBot. Gaz. 24, 66. 



Celloidin Imbedding. 



The following method of celloidin im- 

 bedding has been employed in this lab- 

 oratory for the last two years and has 

 given excellent satisfaction. The method 

 is employed at the University of To- 

 ronto, Mr. E. C. Jeffrey, B. A., the lec- 

 turer in botany, being responsible for 

 many details. For woody stems, any 

 particularly hard tissue, seeds of Gram- 

 ineae, etc., it gives excellent results. 

 Briefly, the different steps are as follows: 



The tissue is fixed in a saturated solu- 

 tion of corrosive sublimate in absolute 

 alcohol. 



Transferred to alcohol* plus a few 

 drops of a strong solution of iodine, for 

 twelve hours. 



The iodine is then thoroughly washed 

 out in several changes of alcohol, the 

 last two changes being absolute alcohol. 



Changed into equal parts of absolute 

 alcohol and absolute ether for twelve to 

 twenty-four hours. 



Thence to two per cent, celloidin (Schei-- 

 ing's shredded, dissolved in equal parts 

 of absolute alcohol and absolute ether, 

 or two parts of ether to one of alcohol) 

 for three or four days. 



