42 



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

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

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

 of sodium.' When tbis oompound is placed in water and exa- 

 mined uuder the microscope, violent diffasíon currents are set 

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

 f ew minutes. "When tbis is o ver, tbe addition of a trace of Hquid 

 ammonia renews tbe activity, wbicb lasts for several hours. 

 Tbese movements be rigbtly attribntes to the liberation of ga- 

 ses by the partióles of tbe compound, and be compares with tbis 

 the liberation of carbonic oxide by living protoplasm, suggesting 

 tbat in tbe discharge of that gas lies tbe secret of tbe strea- 

 ming movements of protoplasm. Professor Herrera was good 

 enougb to seud us a small quantity of bis compound, and on 

 tbis wehave successfully repeated some of tbe experiments he 

 describes. Tbe little mass was particularly active in water witb 

 a trace of ammonia; diffnsion currents, movements of tbe who- 

 lé mass, and tbe protrusion of pseudopodia-Uke processes oc- 

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

 was destroyed from tbe fact tbat tbe mass dit notretain its co- 

 herence; small masses were constantly discbarged from its sur- 

 face, and it seeme,d to melt away in a comparatively sbort ti- 

 'me. In tbis respect it compared unfavourably witb Bütscbli's 

 foams, and we imagine tbat, altbougb Dr. Herrera has imita- 

 ted witb considerable success tbe very complicated cbemical 

 composition and consequent instability of protoplasm, be has 

 not been so successful witb its struoture. On tbe otherband, it 

 is possible tbat tbe substance, in its postal journey from Méxi- 

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

 genious Une of experiment, and wish him all success in bis 

 further attem^ts. 



'^Natural Science." August 1898. 



1 After the análisis of the protoplaema of Aethalivm, by Reinke. 



