394 Mr. G. F. Dowdeswell on the Connective 



changes, the interest of which to me consisted principally in that their 

 presence afforded the evidence that the part observed was in a state of 

 active inflammation. The question I had to answer was, whether or not 

 this state, even when prolonged, is attended with any change whatever 

 in the anatomical characteristics of the preexisting elements. 



Tor this purpose more than a dozen series of observations were made 

 on as many different animals, each series being continued for several days. 

 At the beginning of each series a group of connective-tissue corpuscles, 

 such as the one represented in Plate 8. figs. 3 and 4, was selected and 

 (with the vessels and other structures in relation with it) accurately drawn 

 with the aid of the camera lucida. The preparation was then removed from 

 the microscope and placed in a vessel in which the air was kept saturated 

 with aqueous vapour. The next day, after removing the layer of exuded 

 colourless corpuscles (pus) which covered the exposed surface of the 

 l}Tnph-sac, by directing upon it a gentle stream of salt solution, the outlines 

 of the group of connective tissue were again traced \^ith the aid of the 

 camera. 



In this way several daily observations were taken in respect of each 

 animal. It usually happened that on the fourth or fifth day the circu- 

 lation became impaired or ceased ; but in one instance it continued in 

 vigour as long as nine days, during the whole of which period the same 

 group of corpuscles was kept from time to time under observation. 



The result may be stated in a single line. So long as the circulation 

 continued, " no change whatever took place in the connective-tissue 

 corpuscles, either as regards form or appearance," notwithstanding that 

 the tissue of which they formed part was beset with innumerable emi- 

 *grant colourless corpuscles, i. e. (to use ordinary language) was infil- 

 trated with pus. 



In order that the reader may be put in possession of certain facts 

 which have not been sufficiently noticed in the summary I have now 

 given of the results of my investigation, I will add a few short notes 

 relating to particular experiments. 



The first two experiments differed from the others in this respect, that 

 immediately after beginning my observations I touched the observed part 

 with a drop of water acidulated vdth hydi'ochloric acid (1 part of strong 

 acid to 100 of water). The vascular changes of the early stage exhibited 

 themseh^es in intensity, and resulted in a very abundant emigration of 

 leucocytes ; but as the observation was only continued for two days, the 

 results were of less value as regards the special question under investiga- 

 tion. The fixed corpuscles were remarkably distinct, and these under- 

 went no alteration. 

 > In the fifth experiment (see description of fig. 3) the observation was 

 continued for 5 days, at the end of which period the animal was kdled. 

 At that time the connective-tissue corpuscles, which were distinct and 

 presented very remarkable contours, remained entirely unchanged. 



