294 Chronicles of Science. [April, 



rived at by Fick and "Wislicenus, has been examined experimentally 

 by Professor Pettenkoffer, and more recently also by Dr. Parkes. 

 Professor Frankland has also determined the mechanical value of 

 these forms of food, by experiments on their oxidation. Professors 

 Fick and Wislicenus ate carbonaceous, but no nitrogenous food 

 during their ascent, and hence concluded that all the power not 

 derived from muscle-oxidation was due to the oxidation of the car- 

 bonaceous foods. Pettenkoffer s experiments, which are most conclu- 

 sive as regards the whole question of the source of muscular force, 

 were made by means of a most elaborately constructed chamber, in 

 which a man was placed, and all his excreta, gaseous, liquid, and solid, 

 examined. Dr. Parkes experimented very carefully on two soldiers at 

 Netley Hospital, and communicated his results to the Eoyal Society 

 at the beginning of this year. Both these observers have fully esta- 

 blished that mere force can be supplied by carbonaceous food alone — 

 that nitrogenous food is necessary to build up the worn muscles, and 

 that nitrogenous food, by its direct oxidation, is also efficient in 

 supplying force, and perhaps presents certain advantages over car- 

 bonaceous food in its use, either from the facility of its oxidation, 

 or by a catalytic action on the carbonaceous foods with which it is 

 generally taken. The views we have been briefly noticing are of 

 too great importance to admit of their due appreciation from the 

 perusal of so few lines, and we must therefore refer the reader to 

 the original memoirs in which they are advanced. It should be 

 mentioned that Yoit, a chemist of Munich, appears to have anti- 

 cipated these results by some few years ; his speculations were, 

 however, cast into obscurity by the proximity of the over-shadowing 

 genius whose assertions they controverted. 



Miscellaneous. — Dr. Ernst Haeckel has just published two 

 very remarkable volumes on the philosophy of organic forms, 

 entitled ' The Morphology of Organisms.' He takes much the same 

 line of argument as Mr. Herbert Spencer in his ' Principles of 

 Biology ;' but he enters into greater detail, and develops Iris views 

 further than the English writer. This book, like that of Mr. 

 Spencer, may be regarded as an extension of Mr. Darwin's general- 

 izations, and is, as far as we have been able to observe, a work 

 destined to exert considerable influence in the world of physio- 

 philosophers. We have also to notice a little broehure on ' Spon- 

 taneous Generation and the Development of Infusorial Life,' for- 

 warded to us by Mr. Jabez Hogg. The author has told the story of 

 Heterogenesis (which, by the way, is getting rather old) in a clear 

 and plain manner, drawing attention more particularly to the 

 question of the successive appearance of forms of Infusoria in an 

 infusion, as studied by Mr. Samuelson, Balbiani, and others. There 

 are one or two inaccuracies in nomenclature, such as Acitena ; Vor- 



