341 



case, however, the crystalline units already in existence are 

 coerced merely as to position ; living matter being more com- 

 plex than crystalline, the coercion it exerts is more complex. 

 But if this view be probable, how can we understand inor- 

 ganic substances, such as carbon dioxide, water, and ammonia 

 or ammonium nitrate, or any such grouping of the necessary 

 materials resisting their normal tendency to crystalline aggre- 

 gation, and guiding tliemselves into the complex constitution 

 of living matter. 



It cannot be said that synthetical chemistry affords much 

 more support to Dr. Bastian's views. They seem to imply 

 that any collocation of carbon, hydrogen, nitrogen, or oxygen 

 is capable of spontaneous rearrangemelit into the material 

 substratum of a living thing. Whether the quaternary com- 

 pound be crystalloid or colloid, stable or unstable, in solution 

 or even a solid, is apparently indifferent. The tendency of 

 all colloids is to settle down into stable crystalline forms ; 

 of the reverse passage of crystalloids into colloids Dr. Bastian 

 only assigns a single instance, the metameric change of am- 

 monium cyanate into urea. And urea can hardly be de- 

 scribed as a colloid, since it has a comparatively low equiva- 

 lent, crystallises in slender striated prisms, is not particularly 

 unstable, as it may be boiled witliout undergoing decomposi- 

 tion, and must, as it is not found in the kidneys, be diffusible 

 to be present in the urine. The general mode by Avliich a 

 chemist attempts to construct substances of high molecular 

 complexity is exactly what evolution would lead us to expect. 

 Modifications are introduced into the simplest types, and 

 these, when so modified, are modified again. Every step 

 must necessarily be a position of equilibrium, since otherwise 

 progress would be impossible, and the structure must neces- 

 sarily be commenced again from the beginning. If pro- 

 teinaceous compounds are ever constructed in the laboratory, 

 it will be by such a general process as this. Any substances 

 isomeric with these would be quite as complex, and would 

 be, therefore, as laborious a production. Certainly in no 

 sense can such a substance as ammonium tartrate be an 

 isomer of living protoplasm, and even supposing that tliat 



!ip:a;regate is afforded by tliepectizationof colloid solutions from the gradual 

 witlidrawal of the colloid from the crystallized water. A solution of silicic 

 acid divides into 'a clot and serum,' ending in the production of a stony 

 mass which may be anhydrous, or nearly so. According to Graham, ' the 

 intense synajresis of isinglass, dried in a glass dish over sulphuric acid in 

 vacuo, enables the contracting gelatin to tear up the surface of the gla.~~ 

 Glass itself is a colloid, and the adhesion of colloid to colloid appears to be 

 more powerful than that of colloid to crystalloid.' — (' Proceedings of Royal 

 Society,' vol. xiii, p. 336. 



