372 CHEMICAL ANALYSIS OF ASPERGTLLACE^E. 



On the other hand, urethane, guanidin, allantoin and uric acid 

 remained intact, and the action on benzamide and asparagin was 

 barely appreciable, whilst hippuric acid was split up into glycocoll 

 and benzoic acid. STOLL (I.) also observed the formation of ammonia 

 by Penic. brevicaule from ordinary gelatin. An unrecognisable 

 species, Asp. terricola, is said by WILEY (I.) to be a powerful 

 ammonia-former in soil ; but the production of ammonia compounds 

 from organic nitrogen compounds is not a specific characteristic. 



295. Colouring-matters, Poisons, Oxidations, &c. 



On saccharine substrata containing traces of arsenic or arsenious 

 acids and its salts, Aspergillus glaucus, " Penicillium glaucum" 

 Penic. brevicaule, &c., liberate strong-smelling diethylarsine (see 

 p. 50, vol. ii.). According to R. SCHMIDT (II.), '''Penic. glaucum" 

 and Asp.flavus liberate sulphuretted hydrogen from sulphates, &c., 

 and arseniuretted hydrogen from solutions containing arsenic. 

 DUBOIS (III.) states that Penieilliummycelia, will precipitate basic 

 copper carbonate (patina), from solutions containing copper, on to 

 bronze. The frequently reported fixation of free nitrogen on the 

 part of "Penic. glaucum" and Asp. niger by BERTIIELOT (II.), 

 PURIEWITSCH (VII.) and SAIDA (I.) need only be mentioned here 

 (see vol. i. p. 353). Little is yet known as to the nature of the 

 yellow, brown and red colouring- matters produced by various 

 species (Asp. niger, A. glaucus, A. Ostianus, Penic. luteum, &c.), 

 According to LINOSSIER (II.), that formed by Asp. niger (" Asper- 

 gillin ") is an organic compound of iron ; but this remains to 

 be proved. ZUKAL (III.) states that the colouring-matter pro- 

 duced by Penic. luteum is a " fungus acid " ; at any rate it is a 

 substance soluble in alcohol and reprecipitable by water. A golden 

 yellow pigment is said by MLLBURN (I.) to be produced by Asp. 

 niger under certain conditions, in the form of a granular excre- 

 tion from the aerial hypbse. The alcoholic solution is decolorised 

 by alkali, but not by acid, and the pigment is decomposed by 

 light into a reddish brown substance, so that it is found only in 

 cultures kept in the dark. Possibly the dark pigment of the 

 conidia is formed therefrom by oxidation. R. MEISSNER (I.) 

 carried out tests with the red-brown pigment of Asp. medius 

 (probably synonymous with Asp. glaucus}. The green conidial 

 pigments produced in the vegetative growths of most Aspergil- 

 lacece have not yet received attention. The pigment, soluble in 

 alcohol, of Asp. versicolor, Vuill., varies between yellow-brown, 

 orange and red, according to the reaction of the nutrient solu- 

 tion ; see VUILLEMIN (II.), and also COUPIN and FRIEDEL (1.) on 

 this point. The dependence of the production cf yellow to red 

 colouring-matters on the composition of the substratum, especi- 

 ally as regards Penicillium species (P. olivaceum, P. purpuro- 

 genum and P. rubrum), has been mentioned by STOLL (I.). 



