42 t, 



ne, acetic fibrine, oleic acid, soap, sugar, extract of bile, carbo- 

 nate of soda, lime, and of ammonia, lactate of lime, phosphates 

 of lime and magnesium, sulphates of lime and iron, and chloride 

 of sodium.' When this compound is placed in water and exa- 

 mined under the microscope, violent diffusion currents are set 

 up, and streaming movements of a very active hind last for a 

 few minutes. When this is over, the addition of a trace of liquid 

 ammonia renews the activity, which lasts for several hours. 

 These movements he rightly attributes to the liberation of ga- 

 ses by the particles of the compound, and he compares with this 

 the liberation of carbonic oxide by living protoplasm, suggesting 

 that in the discharge of that gas lies the secret of the strea- 

 ming movements of protoplasm. Professor Herrera was good 

 enough to send us a small quantity of his compound, and on 

 this we have successfully repeated some of the experiments he 

 describes. The little mass was particularly active in water with 

 a trace of ammonia; diffusion currents, movements of the who- 

 le mass, and the protrusion of pseudopodia-like processes oc- 

 curred. We found, however, that the resemblance to protoplasm 

 was destroyed from the fact that the mass dit not retain its co- 

 herence; small masses were constantly discharged from its sur- 

 face, and it seemed to melt away in a comparatively short ti- 

 me. In this respect it compared unfavourably with Butschli's. 

 foams, and we imagine that, although Dr. Herrera has imita- 

 ted with considerable success the very complicated chemical 

 composition and consequent instability of protoplasm, he has 

 not been so successful with its struoture. On the other hand, it 

 is possible that the substance, in its postal journey from Mexi- 

 co, has deteriorated. We think that he has begun a most in- 

 genious line of experiment, and wish him all success in his 

 further attempts. 



"Natural Science." August 1898. 



1 After the analisis of the protoplasma of Aelhalium, by Eeinke. 



