412 



On Nitrogenized Matter in the Atmosphere. [June 20; 



IX. " On the Physical Nature of the Coagulation of the Blood." By 

 Alfred Hutchison Smee, F.C.S., F.S.S. Communicated by 

 Alfred Smee, F.R.S. Received May 27, 1872. 



(Abstract.) 



After passing in review the principal opinions hitherto entertained on 

 the real nature of the coagulation of the blood, the author states that he 

 is led to refer the solidification of fibrin in the process of coagulation to 

 the same class of phenomena as the pectization of colloid liquids, as already 

 hinted by the late Professor Graham and others. He points out at con- 

 siderable length the chief circumstances which influence the change in 

 colloidal fluids, and proceeds to compare the properties of colloid silica 

 with an organic body of the nature of fibrin. 



X. a On the Detection of Organic and other Nitrogenized Matter 

 existing in the Atmosphere." By Alfred Hutchison Smee, 

 F.C.S., F.S.S. Communicated by Alfred Smee, F.R.S. Re- 

 ceived June 1, 1872. 



(Abstract.) 



In this communication the author describes a method which he has 

 devised, and which he names " distillation by cold," by which he believes 

 the detection and determination of ammonia and other organic impurities 

 existing in the atmosphere will be greatly facilitated. 



A glass funnel (usually of 8 or 9 inches) is drawn to a point and closed. 

 It is supported in an ordinary stand, and filled with ice. Condensation of 

 the watery vapour of the atmosphere then takes place ; the dew collects 

 into drops, which trickle down the outside of the funnel, and at last fall 

 from the point, under which a small receiver is placed to catch them. The 

 total quantity of liquid collected in a given time is measured, and the 

 quantity of ammonia determined by Nessler's test. 



By the method of distillation by cold, the author found it possible 

 to distil many substances which are decomposed at a high temperature. 

 Thus many delicate odours of flowers were distilled by placing the flowers 

 under a bell-glass sufficiently large to cover the funnel containing the 

 ice. The odours were found to be more rapidly and completely abstracted 

 by placing a dish with a little ether under the bell-glass at the time of 

 distillation. 



The paper was accompanied by Tables giving the results obtained in 

 107 experiments, together with the atmospheric conditions prevailing at 

 the time. The experiments were made in a garden, in a bed-room, in 

 hospital wards, in the open country, &c. A few of the numbers obtained 

 are here given by way of example ; — 



