46 FIXING AND HARDENING AGENTS. 



(Anal. Anz., xiii, 1897, p. 463), however, has shown that neglect to 

 extract the sublimate from the, tissues in bulk may give birth to serious 

 artifacts, which appear to arise during the imbedding process. So also 

 LOYEZ (Arch. Anat. Micr., viii, 1905, p. 71). HEIDENHAIN (Zeit. 

 wiss. Mik., xxv, 1909, p. 398) removes the iodine from sections by 

 means of sodium thiosulphate. 



You may stain in any way you like. Carmine stains are peculiarly 

 brilliant after sublimate. 



The solutions must not be touched with iron or steel, as these 

 produce precipitates that may hurt the preparations. To manipu- 

 late the objects, wood, glass or platinum may be used ; for dissecting 

 them, hedgehog spines, or quill pens, or cactus spines. 



When properly employed, sublimate is for general 'work un- 

 doubtedly a most useful fixing agent. It is applicable to most 

 classes of objects. It is perhaps less applicable, in the pure form, 

 to Arthropods, as it possesses no great power of penetrating chitin. 

 For cytological work it is, according to my experience, not to be 

 trusted, and only to be recommended where more precise fixing 

 agents are counter-indicated by reason of their lack of penetration, 

 or the like. Amongst other defects it has that of frequently causing 

 very serious shrinkage of cells. 



64. Sublimate with Salt. A solution containing 5 grms. sublimate, 

 0-5 grm. sodium chloride, and 100 c.c. water has been quoted as " solution 

 of GAULE." 



A |- per cent, aqueous solution of sodium chloride saturated whilst 

 hot with sublimate was much recommended by HEIDENHAIN (Festschrift 

 f. Koelliker, 1892, p. 109). 



The addition of sodium chloride allows a stronger solution to bo 

 obtained than can be made with pure water, and also, it is stated, 

 enhances the penetration of the sublimate. But the fixation -precipitates 

 ( 29) formed by the double salt are (according to SPULER, Encyl. mik. 

 Technik., p. 1274) for the most part soluble in water, thus giving rise to 

 imperfect preservation. 



Concentrated (i.e. over 20 per cent.) solution in sea-water is recom- 

 mended for some marine animals. 



STOELZNER (Zeit. wiss. Mikr., xxiii, 1906, p. 25) recommends saturated 

 solution of sublimate in sugar solution of 44 per cent., as isotonic (for 

 warm-blooded animals). 



Liquid of Lang (Zool. Anzeiger, 1878, i, p. 14). For Planaria. 

 Distilled water . . . . . 100 parts. 



Chloride of sodium . . . . 6 to 10 

 Acetic acid . . . . 6 to 8 ,, 



Bichloride of mercury . . . 3 to 12 ,, 



(Alum, in some cases . . . part.) 



65. Alcoholic Solutions. APATHY (Mikrotechnik, p. Ill) recom- 



