Certain Results of Drying Non-sporing Bacteria. 127 



present only in minute amounts. Urease, by determining the resolution of 

 the urea in an abnormal direction therefore serves a most important purpose. 



In studying the phenomena, the mistake has been made hitherto of 

 treating the changes attending the formation and destruction of urea from 

 a point of view which has involved under-rating their complexity. 



We venture to think that the peculiarities to which we call attention are 

 not only noteworthy but should serve as a warning against the danger 

 attending the attempt to formulate conclusions as to the nature of chemical 

 changes without giving due weight to chemical considerations — a practice 

 too frequently followed in these days. 



It is proposed to extend tbe inquiry. 



[The cost of this investigation has been in part met by a grant for which 

 I am indebted to the Government Grant Fund of the Royal Society. — 

 H. E. A.] 



Certain Results of Drying Non-sporing Bacteria in a Charcoal 

 Liquid Air Vacuum. 

 By S. G. Shattock, F.E.C.S., and L. S. Dudgeon, F.RC.P. 



(Communicated by Sir James Dewar, F.R.S. Received February 20, — 

 Read March 14, 1912.) 



The following experiments were undertaken with the object of ascertaining 

 whether non-sporing bacteria, dried in vacuo and kept in vacuo, would 

 survive those dried in and kept in the air, or, on the contrary, whether they 

 would die more rapidly. The action of sunlight and of heat was tested, 

 moreover, upon bacteria dried in vacuo and kept in vacuo, with a view of 

 discovering how far such agencies might be lethal upon dried bacteria, if the 

 latter were supposed present in a free state in interplanetary space. 



In carrying out the work, we have had the invaluable advantage of 

 Sir James Dewar's help, for of the several methods of drying in vacuo, by 

 far the most efficient is that devised by him. This method is so well known 

 to physicists that it will be enough to state here, that after the air of the 

 vessel is exhausted by means of an air pump, the glass connection with the 

 pump is sealed off in the blowpipe flame, and the exhausted chamber is 

 deprived of its remaining gases through a second outlet communicating 

 with a bulb containing cocoanut charcoal (previously freed from gases), 



