9 2 



SCIENCE. 



which serve to direct, relieve, and repair certain defects of 

 the equilibrium. Even when the physician's utmost 

 power is exerted, when the part in question is cut off or 

 destroyed, then also, restoration of the bodily equilibri- 

 um is necessary before any tolerable result can be pro- 

 duced. Also, when the healing powers remove certain 

 imperfections, when an acid is neutralized by an alkali, or 

 when a dormant faculty is roused into fresh activity by 

 any excitation, the cure can only be perfect if the natural 

 relations return again, or else if new ones are formed. 

 Every outward effect is only a means by which to lead the 

 inward formation of the body to free and regular ac- 

 tion. 



No physician can trust wholly to nature, but neither 

 can he produce by art that which takes place naturally in 

 the body. That is the work of the organic healing pow- 

 ers. Every medical man must rely upon their efficiency, 

 but at the same time he has no right to sit idle with his 

 hands in his lap in consequence. On the contrary it is 

 frequently necessary to employ the most forcible interfer- 

 ence in order to regulate the action properly. In particu- 

 lar diseases, how much nature is able to perform, and how 

 much the physician is compelled to do, can only be ascer- 

 tained by personal experience, and can be determined a 

 priori by no theory. On the other hand, how far, in cer- 

 tain cases, medical treatment must extend, and how far 

 the natural course is to be influenced by the physician, is 

 not merely a question of experience, but frequently one of 

 scientific value, which only an educated and cultured 

 physician is capable of undertaking. Experience alone, in 

 the medical world, produces only adventurers who per- 

 haps may succeed now and then, but for whom self-reli- 

 ance is always a risk. Such experience as is led and reg- 

 ulated by Science alone is capable of removing all bar- 

 riers, and able to designate the realm in which nature 

 and the physical organic forces have the supreme com- 

 mand. 



Separation of Cadmium and Zinc — In a memoir in- 

 serted in the Annales de Chimie et de Physique (Series 4, vol. 

 30, p. 351), M. Riche described a process for the determina- 

 tion of zinc, either by the decomposition of the acet3te or 

 by the electrolysis of the solution containing sulphuric acid. 

 Several researches on the same subject have since been pub- 

 lished by different authors. MM. Beilstein and Jawein, 

 whilst confirming the results of Riche, employ the following 

 process : — The nitric or sulphuric solution of zinc is mixed 

 with caustic soda until precipitation ensues, and then with 

 potassium cyanide till the precipitate is re-dissolved ; the 

 electrolysis is then effected with four Bunsen elements. 

 The determination of cadmium has been effected by the 

 same chemist under the same circumstances by means of 

 the current from three elements. M. Millot has recently 

 given a process for the determination of zinc by electrolysis 

 of a solution of this metal in potassa. M. Edgar Smith ob- 

 tains a precipitate of metallic cidmium by passing a strong 

 current through a solution of the acetate. These procedures 

 have the defect of not serving for the separation of cadmium 

 and zinc, as the two metals are precipitated simultaneously. 

 They may be separated as follows : — The solution contain- 

 ing the two metals in the state of acetates is mixed with 2 

 or 3 grms, sodium acetate, and a few drops of acetic acid. 

 The current from two Daniell elements is then passed 

 through the solution as described by M. Riche in his 

 memoir. The cadmium alone is deposited in a crystalline 

 layer at the negative pole, the zinc remaining in solution. 

 The process requires the aid of heat, and requires three to 

 four hours for quantities of oi8ogrm. to o - 2to grm. cad- 

 mium, and as much zinc. The deposit is effected in the 

 crucible, and the liquid is then drawn off and serves for the 

 determination of the zinc, according to M. Riche's process 

 The deposit is washed first with water, then with alcohol, 

 dried, and weighed. K the zinc and cadmium are present 

 as sulphates the author recommends precisely the same 

 method. Or the sulphuric solution may be mixed wiih 

 ammonia and ammonium sulphate. — A. Yver. 



MANUFACTURE OF YEAST WITHOUT ALCO- 

 HOLIC FERMENTATION. 



A method of manufacturing yeast without alcoholic 

 fermentation, and without th-: tormation of subsidiary 

 products has been patented in England by Dr. J. 

 Rainer, of Vienna. The process is carried out in the fol- 

 lowing manner: — The vegetable albuminous substances 

 in the corn cereals or other vegetables, or such refuse of 

 industrial establishments as bran comings, malt residuum, 

 gluten, and the like, are extracted with the aid of from 15 

 to 20 parts by measure of water, made slightly alkaline. 

 They are then either peptonized by adding an excess of 

 lactic acid (about 4 per cent.) or mineral acids (about .25 

 per cent, of phosphoric acid, or about .4 per cent, of 

 either sulphuric acid or hydrochloric acid) at a tempera- 

 ture of from 55 to 100 degrees Fahrenheit, or they are at 

 once macerated in dilute solutions of the above acids and 

 simultaneously converted into peptone. A portion of the 

 albuminous substances (from 5 to 10 per cent, of the total 

 weight) in the dried comings will be already transformed 

 into peptone by the process of vegetation. The albu- 

 minous substances in cereals, maize, or other vegetables, 

 and in bran and malt residuum are transformed into 

 peptone by the addition of diastase. In order to effect 

 the conversion it is sufficient to add to one part by weight 

 of the albuminous matter when dry, one part by weight 

 of dry malt, or five parts by weight of comings. As 

 stated the liquid in which the albuminous matter is to be 

 transformed into peptone must contain lactic acid (4 per 

 cent.), phosphoric acid (as much as .25 per cent.), sul- 

 phuric acid or .hydrochloric acid (about .4 per cent.), 

 because the presence of an acid is absolutely necessary 

 in the process of converting these substances into pep- 

 tone. 



A temperature of about 100 degrees Fahrenheit is the 

 most suitable for the conversion of the substances into 

 peptone, and a period of from 18 to 20 hours will be 

 sufficient to effect it. It may, however, be also carried 

 out at lower temperatures during a correspondingly 

 longer time. In working comings it is superfluous to 

 add malt, because the diastase contained in the comings 

 is more than sufficient for the process of conversion into 

 peptone. Therefore it is only necessary in this case to 

 use one of the above-named acids in the proportions 

 given. The slimy pectates contained in the comings as 

 well as in other materials are dissolved by the combina- 

 tion of diastase and acids. When the preparation of 

 pure peptone is required the pectates may be sepa- 

 rated by an endosmotic apparatus or dialysator, in 

 such a manner that the peptone is dialysed through 

 proper membranes in water.while the gelatinous pectates 

 remain as a residuum. The acids are neu'ralized by 

 means of soda, or by saturating the liquid with basic 

 phosphate of lime. The prepared peptone liquid, with or 

 without a percentage of sugar, may be shipped as a sale- 

 able article, or it may be delivered in a dry state, or as a 

 syrup or extract obtained by boiling the liquid down in a 

 water bath, by steam, or preferably in a vacuum. The 

 liquid containing peptone may be separated from solid 

 matter (hydrocarbons, vegetable fibre, or the like) by 

 simple extraction, maceration, or pressure, or by centri- 

 fugal action, or it may be carefully cleaned by filtration 

 or settling. It is advisable, however, before cleaning by 

 filtration or settling to naturalize any acid present by 

 means of soda, or to saturate the liquid with basic phos- 

 phate of lime, the latter being preferable because the 

 phosphoric acid required by the yeast is thus abundantly 

 furnished to it. In order to start the growth of yeast, 

 gelatinized starch is added after being transformed in the 

 usual way into dextrose by boiling with an addition of 

 mineral acids. In the place of starch thus prepared an 

 addition may be made of maltose, molasses, or sugar 

 mixed with beer-yeast or compressed yeast. The amount 

 thus added should correspond to the percentage of pep- 



