413 



Similar improbability attaches to a view which supposes a fluid of 

 such chemical and such morphological characters as the blood of the 

 Lamellibranchiata, to suffer dilution to such an extent as the ob- 

 servable distention of their foot would necessarily imply ; and which 

 argues from phenomena noticed on the sudden removal of the animal 

 from the water, as though they could be regarded as identical with 

 normally occurring physiological processes. 



As their injections seem to them to prove the existence of a system 

 of vessels distinct from and yet in most close apposition to the blood- 

 vessels, and permeating the several tissues of the body in company 

 with them, the facts of the case seem to the authors to necessitate the 

 belief that a transference of fluid takes place, as in other organisms, 

 from the latter to the former set of vessels. 



The animals experimented upon were Unionidse of the two species, 

 Anodonta Cygnea and Unio maryaritifera. 



V. " Notes of Researches on the Poly-Ammonias." No. XVI. 

 Triatomic Ammonias. By A. W. HOFMANN, LL.D., F.R.S. 

 Received July 5, ]861. 



In a short paper which I had the honour of submitting to the 

 Royal Society about a year ago, I endeavoured to delineate the 

 general results to which my experiments on the Polyatomic Bases had 

 led me. I showed that the construction of these bodies may be 

 accomplished in two essentially different ways. In the first place, a 

 number of ammonia-molecules may be joined by the insertion of a 

 polyatomic radical, the atomicity of the radical determining the 

 number of the ammonia-molecules thus united. 



Examples of compounds formed upon this principle have been fur- 

 nished by my researches on the phosphonias. 



Again, the accumulation of the ammonia-molecules may be 

 attempted by increasing the number of polyatomic radicals of given 

 atomicity used as binding material. It is obvious that theoretically 

 any number of ammonia-molecules may be held together by diatomic 

 molecules, provided we appropriately increase the number of the 

 latter. 



