SCHULTZE'S FILMS. 



[ 683 ] 



SCLEROTIUM. 



SCHULTZE'S FILMS. See SILICA. 



SCHULTZE'S TEST. This was origin- 

 ally proposed by Pettenkofer as a test for 

 bile ; but Schultze found that it reacted also 

 with several other substances, and especially 

 the proteine compounds. In this application 

 it is often of use in discriminating one kind 

 of tissue or substance from another. It con- 

 sists in treating the matter with strong sul- 

 phuric acid, and then adding a little syrup. 

 The characteristic reaction is the produc- 

 tion of a purplish-red colour. The best 

 method of proceeding is to wash the sub- 

 stance in question, then to moisten it with 

 a drop of syrup, and finally to add the acid. 



The tissues and substances affected by 

 it are muscular tissue, both striated and 

 unstriated ; nerve-tubes and cells ; the cor- 

 puscles of blood, pus, and mucus ; epithelial 

 and epidermic scales ; hairs ; feathers; horn ; 

 whalebone ; and the cellular portions (cell- 

 contents ?) of Fungi and Algae. 



Those in which the reaction is not pro- 

 duced are areolar tissue, elastic tissue, gela- 

 tine and chondrine, chitine, silk, cellulose, 

 gum, starch, and vegetable mucus. 



BIBL. Schultze, Liebigs Annalen, 1849, 

 CJiem. Gaz. viii. 98. 



SCHULZE'S TEST. This consists of a 

 solution of chloriodide of zinc, and is used as 

 a test for cellulose, which it colours blue. 



The original directions given for its pre- 

 paration are indefinite ; they are as follows : 

 dissolve zinc in muriatic acid, evaporate 

 the solution with excess of zinc until it ac- 

 quires the consistence of syrup, and dissolve 

 in this enough iodide of potassium to satu- 

 rate it ; iodine is then added, and the solu- 

 tion diluted with water if necessary. 



Radlkofer recommends zinc to be dis- 

 solved in muriatic acid, the solution to be 

 evaporated at a temperature but little above 

 that of boiling water, when a liquid of about 

 2'0 sp. gr. is obtained. This is diluted with 

 water until its sp. gr. is 1'8 ; if its original 

 sp. gr. was 2'0, 12 parts by weight of water 

 must be added to 100 parts of the solution. 

 In 100 parts of this liquid, 6 parts by weight 

 of iodide of potassium are to be dissolved at 

 a gentle heat, and the mixture heated with 

 excess of iodine until the latter is no longer 

 dissolved, and violet fumes become percep- 

 tible over the liquid. 



This reagent has the consistence of strong 

 sulphuric acid, and is pale yellowish-brown. 

 It must be kept in a well-stoppered bottle. 



BIBL. Schulze, .F/ortf, 1850, 643; Schacht, 

 Mikroskop. 30 & 197 ; Radlkofer, Liebitfs 



Annalen, xciv. 332, Chcm. Gaz. 1855, xiii. 

 372. 



SCIA'DIUM, Al. Braun. A genus of 

 Unicellular Algse. The young plant is 

 attached to foreign bodies, and consists of a 

 cylindrical cell (), in which are produced 

 eight gonidia ; the top of the cylinder fall- 

 ing off like a cap, the gonidia emerge and 

 form an umbel of similar cylinders (&), the 

 bases of which stick in the primary cell. 

 Each new cell repeats the process, so as to 

 form a compound umbel ; but the gonidia 

 of the third generation (c) are set free, form- 

 ing the primary cells of new families. 



S. arbuscula (PI. 5. fig. 3) ; on freshwater 

 Confervoideae &c. Rabenhorst unites this 

 genus with Ophiocytium. 



BIBL. Braun, Alg. Unicett. 48; Currey, 

 Mic. Jn. vi. 212 ; Rabenhorst, Alg. iii. 66. 



SCI'RUS, Herm.,=^c7e//pt.; including 

 the species with apparently a head and neck. 

 5 species, found among mosses, on insects, &c. 

 (Murray, EC. Ent. 144). 



SCLEREN'CHYMA. See TISSUES, 

 VEGETABLE. 



SCLEROCHI'LUS, Sars. One of the 

 Cytheridce, with smooth, hard, elongate, 

 bean-shaped valves ; lower antennae 5- 

 jointed ; upper 6-jointed, with long setae ; 

 eye single. One living British species; 

 common. (Brady, Linn. Tr. xxvi. 455.) 



SCLERODER'MA, P. A genus of 

 Trichogastrous Fungi having a firm peri- 

 dium, which bursts irregularly, containing 

 large granulated spores separated in masses 

 by floccose veins. 



Four species have been found in this 

 country, one of which when young is sub- 

 stituted for truffles, though without any of 

 the fine aroma. 



BIBL. Fr. Syst. Myc. iii. 46 ; Berk. Outl. 

 t. 15. f. 4 ; Cooke, Handb. 374. 



SCLEROT'ICA. See EYE (p. 310). 



SCLERO'TIUM, Tode. A large collec- 

 tion of fungoid structures were formerly 

 gathered together under this name, among 

 others the preparatory form of the ERGOT 

 fungus. They are now all regarded as 

 consisting of the mycelia of fungi in an 

 imperfect state. The sckrotioid state exists 

 when the mycelium forms hard tubercular 

 masses. Analogous masses of mycelial 

 structures occur, in a pulpy condition, in 

 the Vinegar-plant; in a filamentous con- 

 dition, in those fungi forming large masses 

 of barren byssus, &c. ; in other cases, as in 

 some of the Myxogastres, the structure is 

 membranous. 



