CHEMISTRY. 949 



"As revealed by the method potassium occurs in both the cytoplasm and the 



extracellular structures. In the latter it is |. resent as a produci of impregnation and 

 infiltration ami, as a consequence, there are tew such structures that are fie.- from it. 

 In intercellular material ami in inert or dead matter it is usually very abundant. 

 The cell nucleus does ool normally contain the slightest trace of potassium. . . . 

 Nerve cells are wholly free from potassium ami this freedom extends to the den- 

 drites ami axons. . . . 



"The potassium obtaining in cytoplasm occurs in two conditions, that of physio- 

 logical precipitation, ami that of physiological or biochemical condensation. 



"The precipitation is not of a physical character, hut may perhaps he of the nature 

 of fixation, in an inert form, of the potassium in passive colloidal material in the 

 cytoplasm. This precipitation is the process, apparently, by which living, active 

 cells dispose of the excess of potassium salts which may invade them, as in the case 

 of vegetable forms, in very greal excess. . . . 



"In smooth muscle fiber the potassium found is scant and it is diffused throughout 

 its cytoplasm, Imt in striated fiber there is a condensation of the potassium in the 

 dim hands, the rest of the fiber being free from the element. When the fiber is in 

 the contracted condition the potassium is most abundant in the middle third of the 

 hand, at least such is the case in the wing muscles of the scavenger beetle. It is the 

 doubly- refractive substance of the dim hands that, apparently, constitutes the con- 

 tractile material, that is the inogen of Hermann, and its association with potassium 

 suggests some relation of the latter, not with contraction, for smooth muscle fiber 

 shows that property, nor with tetanus, for in eardiae muscle the potassium is dis- 

 posed as in ordinary striated fiber, but with rapidity of contraction, which distin- 

 guishes striated tiher from smooth. 



"There is in the secreting cells of the pancreas of the guinea pig ami rabbit a 

 remarkable concentration of potassium compounds in that portion of the granular 

 zone immediately adjacent to the lumen, while the remainder of the cytoplasm is 

 free from them. 



"There are organisms which manifest a distinct capacity to absorb potassium and 

 amongst them is one, parasitic on Spirogyra, whose mycelial threads exhibit kalio- 

 philism in a special degree." 



It was found that the cobalt reagent used gave a precipitate with creatin, but not 

 with a number of amid acids, acid amids, and other substances tested. 



Exercises in practical physiological chemistry, S. W. Cole [Cambridge: W. 

 Heffer & Sons; London: Simpkin, Marshall & Co., 1904, PP- ir >-': rev. in Lancet [Lon- 

 don], 1905, I. No. 14, p. 936). — A text-book designed for laboratory use. 



Preliminary communication on the methods of analysis adopted at the 

 Twentieth Convention of the Agricultural Experiment Stations in the Ger- 

 man Empire, H. Neubauer and V. Schenke i Landw. Vers. Stat., 61 1 1905), No. 5-6, 

 pp. 851-S56).—A brief summary of the proceedings of this convention. 



Miscellaneous analyses, <;. E. Colby [California Sia. Rpl. 1904, j>- 48). — Brief 

 notes are given on the results of examinations of oranges, dried prune-, dried tigs, 

 olive oil, pickled olives, olive soap, vinegar, salt, "niter earth,'' sulphur, etc. 



Methods of chemical analysis as applied to sewage and sewage effluents, 

 G. McGowan, R. B. Floris, and R. S. Finlow (Roy. Com. Sewage Disposal {Great 

 Britain] Rpl., ; ,«'■ 5, pp. 70, figs. 7) . — Descriptions are given of methods of 



sampling; preliminary observations on color, smell, reaction, matter in suspension, 



the presence of unusual substances, etc., are described; and methods of determining 



free and salim- am la, albuminoid ammonia, nitric and nitrous nitrogen, organic 



ami total nitrogen, oxygen absorbed, combined nitrogen, total, suspended, and 

 soluble solids, cellulose, dissolved gases, etc., are explained in detail. 



