MOUNTING 



787 



MOUTH 



scially in bacterial preparations. Cloves, Oil of. 

 This has a tendency to form very convex drops, and to 

 render tissues brittle ; sometimes this is considered ad- 

 vantageous in minute dissections. It clears objects better 

 than balsam, and may be used in connection with bal- 

 sam mounts ; but, as it dissolves celloidin, it should not 

 be used for sections imbedded in that medium. It dark- 

 ens with age, and is commonly adulterated with phenol, 

 which may be detected by Fluckiger s test : i. e., shake 

 the suspected oil with fifty parts of hot water, slowly 

 evaporate the aqueous portion to a small bulk, and 

 sst it with a drop of ammonia and a pinch of chlo- 

 id of lime. If phenol be present, a green color is 

 leveloped, which changes to a permanent blue color. 

 Topal Varnish. Pale copal varnish, of the consis- 

 ;ncy of oil, is recommended as a substitute for Can- 

 ia balsam. For very large sections it is very useful, 

 lakes no bubbles, and it dries so hard, if slightly 

 farmed, as to stand wiping and dusting with a soft 

 brush. By its use large and expensive cover-glasses 

 lay be dispensed with. Creasote (Stieda's Aletkod). 

 very useful clearing-agent and temporary mount for 

 vatery sections. Rinse the sections in water; bring 

 lem upon the slide ; remove the water by means of 

 ilotting-paper ; add a drop of creasote at the side ; 

 yhen clear, draw off the creasote in the same way 

 id replace with dammar. Csokor's Cement for 

 iLYCERiN-MOUNTS. Pure Venice turpentine is poured 

 ito some melted wax upon a water-bath until a 

 jrtion taken out on a glass rod becomes stiff at 

 and does not stick to the hand. Dammar, 

 ed as a substitute for Canada balsam. Gum dam- 

 ar dissolved in benzol, or xylol, about loo grms. of 

 ammar to 100 c.c. of benzol. Dammar and Mas- 

 IC, much used as a substitute for Canada balsam. 

 Hrst solution : Gum dammar loo grms. , oil of tur- 

 pentine 200 c.c. Dissolve and filter. Second solu- 

 tion: Gum mastic 50 grms., chloroform 200 grms. 

 Mix the two solutions. Farrant's Medium, re- 

 commended because tissues mounted in it preserve 

 their normal appearance, and in that it is more con- 

 venient than glycerin, as it dries at the edges and fixes 

 the cover-glass. Tissues may be mounted in it directly 

 om water, but it is better that they be soaked for a 

 e in dilute glycerin. Formula: Dissolve I grm. 

 of arsenious acid in 200 c.c. of distilled water. In 

 this fluid dissolve, at the ordinary temperature, 130 

 grms. of gum acacia, with frequent stirring; add 100 

 c.c. of glycerin; mix. Filter the solution through 

 fine Swedish paper upon which has been deposited a 

 thin layer of talc. Glycerin. When this is used as a 

 mounting-medium, the best quality should be em- 

 ployed. A mixture of equal parts of water and gly- 

 cerin is often preferred. As a mounting-medium for 

 plant-tissues, the best preparation is glycerin and 

 acetic acid in equal parts, boiled and filtered. For 

 specimens stained in carmin, the glycerin should be 

 acidulated with one per cent, of formic or acetic 

 acid. Glycerin-jelly. This is a mixture of gly- 

 cerin and pure gelatin ; it is liquid at the temperature 

 of boiling water, and solidifies on cooling. Speci- 

 mens should generally be saturated with glycerin be- 

 fore mounting. Goodale gives the following formula : 

 One part of gelatin is soaked in six parts of water for 

 two hours, seven parts of glycerin are added, and one 

 part of carbolic acid is added to the whole. The 

 seated for fifteen minutes with constant stirring, 

 and then filtered through glass-wool in a hot funnel. All 

 of the ingredients must be absolutely pure. Wrap the 

 cork of the bottle containing the jelly in a thin piece 

 of linen which has been dipped in pure carbolic acid. 

 Another formula is the following: Soften 25 grms. 



the 



Z 



of i 



(6.4 3 ) of gelatin in cold water. Warm the gelatin 

 over a water-bath; add 5 c. c. (1.3 f 3 ) of white of 

 egg, to clarify. Do not heat above 75 or 8o° C. (167 

 or 176 F.). Pass through a hot filter, mix with an 

 equal volume of glycerin, and add 5 grms. (1.3 3 ) of 

 chloral hydrate. Glycerin-solution. Glycerin 

 10 parts, glucose 40 parts, spt. of camphor IO parts, 

 distilled water 140 parts. Mix and filter. The ad- 

 vantage of this medium is that it possesses the refrac- 

 tive index 1. 37 in the yellow ray. Gold Size, 

 employed as a sealing for glycerin and potash mounts. 

 H oyer's Medium. (a) For anilin preparations : A 

 filtered solution of selected white gum-arabic in a 50 

 per cent, aqueous solution of acetate of potassium or 

 acetate of ammonium, (b) For carmin preparations and 

 hematoxylin preparations : The same as the first, but 

 a concentrated solution of chloral hydrate, to which has 

 been added from 5 to 10 per cent, of glycerin, is sub- 

 stituted for the solution of potassium or ammonium. 

 It is recommended by Strasburger for plant-tissues. 

 Lavdowsky's Medium, for mounting sections. It 

 also clears somewhat. It consists of gum-sandarac 30 

 grms. , dissolved in absolute alcohol 5 c.c. A thin 

 solution may also be made by diluting with an equal 

 quantity of absolute alcohol. Maskenlack. An ad- 

 hesive varnish prepared in Germany for securing the 

 edges of cover-glasses when mounting-media lacking 

 tenacity are used. Mikroskopirlack. A German 

 varnish employed for securing the edges of cover- 

 glasses when mounting-fluids lacking tenacity are used. 

 Shellac. This is frequently employed in building 

 up cells or securing the edges of cover- glasses. It may 

 be best used in alcoholic solution, to which a few 

 drops of castor oil are added to prevent brittleness. It 

 may be tinged with the anilin dyes. Smith's (Ham- 

 ilton) High-index Mounting-fluid for Dia- 

 toms. In two (2) fluid drams of glycerin-jelly, 

 made in the usual way, dissolve in the cold ten (10) 

 drams of chemically-pure stannous chlorid. When 

 the solution is complete, bring to the boil for a few 

 minutes and filter while hot. The fluid must be used 

 hot. This is done by simply heating the slide at the 

 time of mounting. It has a refractive index (approxi- 

 mately) of 2.40. The color is equal to that of old yel- 

 low balsams. Diatoms mounted in it show with 

 wonderful clearness. Turpentine, used as a clearing- 

 agent, as a solvent for balsam, and as a medium for the 

 temporary examination of sections. Its refractive index 

 is such as to render it a valuable medium. Thickened 

 Turpentine (the verharztes Terpentinol of German 

 writers), which is prepared by exposing rectified tur- 

 pentine in thin layers to the air for several days, does 

 not shrink alcohol preparations, as does the ordi- 

 nary spirit. White Lead {with oil), used in build- 

 ing up cells and sealing mounting-media that lack te- 

 nacity. Xylol, used in preparing objects, and as a sol- 

 vent for Canada balsam. It is suitable as a medium for 

 preliminary examination, on account of its great solu- 

 bility. Xylol-balsam. Canada balsam dissolved 

 in xylol is used as a medium in mounting microscopic 

 objects. 



Moussena [moc/ -se-nah or moo-se'-nah) [African]. 

 The bark of Albizzia anthelminthica, a good-sized 

 shrub of Abyssinia. It is said to be an efficient tenia- 

 cide, acting without purging, nauseating, or producing 

 colic. See Acacia. 



Moussenin {ntoo'-sen-in) [moussena}. The alkaloid 

 found in Moussena bark. It was discovered by Theil 

 in Albizzia anthelminthica, and resembles saponin. It 

 is also spelled mussenin. 



Moustache {nuts' -tash ). See Mustache and Mystax. 



Mouth (j>iowth ) [ME., mouth, mouth]. The proximal 





