834 SUMMARY OP CURRENT RESEARCHES RELATING TO 



phenomenon of the resorption of starch-grains ; and of the rise of 

 temperature which takes place during germination ; as also the pro- 

 duction of other substances, hitherto unexplained, in the elaborated 

 sap. 



Fermentation of Nitrates.* — The researches of MM. Schloesing 

 and Muntz have proved that nitrification, in the ground and in organic 

 liquids, is due to development of small organisms (corpuscules 

 brillants of Pasteur).| MM. Gayon and Dupetit having been led to 

 think that the opposite process, viz. reduction of nitrates, is also a 

 physiological phenomenon, have investigated the matter experiment- 

 ally, and found a microbe which attacks nitrates in presence of organic 

 matters (e. g. sewage water containing a little nitrate of potash with 

 some altered urine, or preferably, chicken-broth) which cause the 

 products of fermentation of the nitrate to enter into new combinations. 

 Pure nitrogen is liberated, representing a large proportion of that of 

 the nitrate, the rest forming ammonia, and perhaps amidized deriva- 

 tives of the organic matter, the liquid being filled with the microbes. 

 Carbolic acid and salicylic acid, in antiseptic, or even larger doses, 

 not only do not hinder the life of the reducing microbe, but them- 

 selves disappear completely with the nitrate, in the same way as 

 sugar or propylic alcohol. 



Algae. 



Composition of Fucus amylaceus.J — The chemical analysis of 

 the alga Sphcerococcus lichenoides Ag., known as Fucus amylaceus, has 

 yielded the seven following carbo-hydrates : — 



1. A mucilage soluble in water. The drug extracted with cold 

 water yields a small quantity of mucilage which is precipitated in 

 alcohol, and is converted into sugar by acids. Mannite and grape- 

 sugar are wanting in the aqueous solution. 



2. A gelatinous non-nitrogenous substance, with ash amounting to 

 4*43 per cent.; the analysis yielding C 45*55, H 5-99 per cent., 

 nearly corresponding to the formula 4 (C 6 H w 5 — H 2 0). Seven parts 

 in bulk of alcohol produce a precipitate in the hot solution ; its 

 solubility in cupric oxide distinguishes it from the lichenin extracted 

 by Berg from Cetraria islandica ; iodine and H 2 S0 4 do not colour 

 it blue ; hence it is not a soluble modification of cellulose. This 

 gelatinous substance must not be confounded with the pararabin 

 discovered by Porumbaru in the Japanese Agar Agar. The aqueous 

 solution of the foregoing turns the plane of polarization to the left, 

 and is extremely opalescent. 



3. Starch-flour. 



4. A pararabin-like substance. The residue of the Fucus was 

 macerated in one per cent, muriatic acid, pressed out, filtered, and 

 the product precipitated with alcohol. The purified precipitate 

 is a white powder containing sulphate of lime. The substance freed 

 from ashes shows the following composition: C 44*78, H 5*95 



* Comptes Renrlus, xcv. (1882) pp. 644-6. 

 t Cf. this Journal, iii. (1880) p. 314. 



\ SB. Naturforsch. Ges. Dorpat, vi. (1881) pp. 39-48. See Bot. Centralbl., 

 xi. (1882) pp. 5-6. 



