CHEMISTRY. 



administered for experimental pur- 

 posss are excluded because natural products 

 only are contemplated. The artificial forma- 

 tion of natural products hssmn with obstrvm- 



aristaf from experiment* n.-t primarily 



d to that end. It WM not till the 



of ohsmtnal structure had riarn t<> tin- rank of a 

 guide that the more complicated syn- 

 i rendered possible by more exact 

 An understanding i* needed as to 

 b meant by an ornnic synthesis. There 

 trs to be an impression among many chem- 

 ists that a synthesis is effected only when ; , 



up from simple molecules. If the 

 ,3m can be formed directly from 

 its, then the synthesis is supposed to 

 : but the great interest of all syn- 

 thetic work arises from our being able bv labo- 



to obtain compounds which are 

 ired in Nature's laboratory the 

 living organism. Now. if we confine the notion 

 of tyntheais to the building up of molecules from 

 simpler molecules or from atoms, we exclude 

 one of Nature's methods of producing many of 

 those very compounds which we claim to have 

 synthesixed. There can be no doubt that a large 

 proportion, if not a majority, of the natural 

 products which have been prepared artificially 

 are not synthesized by the plant in the sense 

 of building up at all. They are the results of 

 the breaking down of the degradationof 

 complex molecules into simpler ones. The au- 

 thor urges therefore that if in the laboratory we 

 arrive at one of these products by decomposing 

 a more complex molecule by means of suitable 

 we have a right to call that a synthe- 



sis, provided that the more complex molecule 

 which gives us our compound can be in its turn 

 syntbeaued by no matter how many steps from 

 to constituent atoms. What evidence is there 

 that any one of the 180 compounds which have 

 been prepared artificially is produced in the or- 

 ganism by a direct building up f Is not the op- 

 posite view quite as probable f May they not 

 from the simplest to the most complex be prod- 

 not* of the degradation of still more complex 

 molecules f It must be remembered that a com- 

 pound or mixture of a highly complex proteid 

 nature protoplasm is always present in the 

 living organism and is the essence of the vital- 

 ity. Supposing that the products in question 

 are formed by chemical actions upon this, there 

 is no such process as the direct combination of 



dead molecules to build up a complex substance, 

 but everything must paw through the viul mill. 

 The supposition that chemical synthesis in the 

 organism b the result of the com) 

 highly complex molecules with simpler roole- 

 oulea, and that the unstable compounds thus 

 fuciatnl then undergo decomosition with the 



formation of new product*, may be provbionall 

 ealledl the protoplasmic theory of vital sy 



In 



y 

 syn- 



attempt of Dr. Backhouse to produce 

 artificial human milk, milk carefully collected 

 with due attention to cleanliness b submitted 

 to fermentation by rennet, in the course of 

 which a relatively rich milk *rum is produced 

 containing albumin and milk sugar. This 

 arum b sterilized, and cream b added. A ma- 

 terial b thus produced which closely resembles 



human milk, and can be varied in composition 

 according t<. the age of the person u>ing it. or 

 according to what lie needs. Tin- author sug- 

 gests that the sterilization of milk should, if 

 possible, be carried out on the large scale in 

 dairies before distribution; and that in this 

 way, better apparatus being to hand, more cl -an 1 y 

 and more effectual results will be obtained than 

 tin- Mcrili/ation is left in the hands of 

 private persons. Dr. I 1 . Frankland claims to 



r.-par-'d an artificial human milk by a 

 similar but slightly different process adding 

 milk sugar to make up the dli< icnry in the 

 cow's milk in 1854, and that his recipe has 

 been advantageously used in private and hos- 

 pital prac ' 



The synthesis of caffeine has been effected by 

 Fmil Fischer and Lorcnz Ach, of Berlin. Th'e 

 substance is obtained by a series of processes 

 from the product of the condensation of dimethyl 

 urea and malonic aci<l. 



Anew series of iron nitroso compounds de- 

 scribed by K. A. Hoffmann and <>. F. Waft 

 affords fine examples of the synthetical produc- 

 tion of complex inorganic substance-. The 

 compound PeVNO)SiOIHiO is precipitated in 

 red-brown leaflets by the action of nitric oxide 

 with ferrous sulphate and potassium thiosul- 

 phate. This substance is with ditticulty soluble 

 in water, and gives a grecni.-h-yrlli.w solution, 

 without decomposition, when dissolved in con- 

 centrated sulphuric acid. Ammonium and so- 

 dium compounds of similar composition and 

 properties have been prepared. The-e com- 

 pounds are classed as salts of dinitrosoferrothio- 

 sulphuric acid. Cobalt compounds can be ob- 

 tained, in which cobalt replaces the iron, but 

 with greater difficulty. 



A compound of aluminum chloride with ben- 

 zovl chloride has been obtained in large crys- 

 M. I'. -rrier. Such compounds are of 

 particular importance, in view of the remarkable 

 part which aluminum chloride lias been found 

 to play in synthetical chemistry, as affording 

 some insight 'into the nature of tlie intermediate 

 reactions upon which the apparently catalytic 

 action of this salt depends. The crystals 'de- 

 compose rapidly in moist air, and are instantly 

 decomposed by water, forming an aqueous solu- 

 tion of aluminum chloride, hydrochloric acid, 

 and benzoic acid. They are readily soluble, 

 however, without decomposition, in carbon bi- 

 sulphide. The formation of compounds of this 

 nature appears to be general throughout the 

 aromatic series. Compounds containing the 

 aromatic ketones, ethers, and phenols, the <hl<.- 

 ride of phthallic acid, and the chloride of butyric 

 acid have also been obtained. 



Agricultural Chemistry. From investiga- 

 tions of the chemical history of the barley plant 

 carried on during 1894 and 1895 on the experi- 

 mental plots at Woburn, C. P. Cross and <'. 

 Smith draw the general conclusions that the 

 conditions of soil and nutrition have very little 

 influence on the composition of the plant; that 

 the straw grown in wet seasons has a high feed- 

 ing value, and conversely a low paper-making 

 value; and that the compositions Known as fur- 

 furoids are continuously assimilated to perma- 



issue in a normal season, but in a very 

 dry season the permanent tissue is drawn upon 





