240 PROCEEDINGS OF SOCIETIES. 



heads, was of a bluish tint ; in fact, they looked very like some 

 minute " nostochaeeous " joints, and Mr. Archer thought there 

 could be little doubt but that these beads or heads corresponded 

 to the " spores " of characteristic " Nostochacese," with which, 

 indeed, the " Bacterieae" should be associated. (It is but right to 

 mention that these notes and views were laid before the Club 

 prior to the appearance, in Dublin at least, of Professor Cobn's 

 recent paper on Bacterians in the late number of his ' Beitrage,' 

 in which similar views are expressed, and in which he now refers 

 the various forms to their respective places in the system amongst 

 Phycochromaceous Algae.) 



Medical Micboscopical Society. 



17th December, 1875. 



H. PowEE, Esq., Vice-President, in the Chair. 



Da. Pbitchabd exhibited in action the new freezing machine 

 for cutting microscopic sections, which has already been described 

 in the ' Lancet ' for December 11th, 1875. 



The principle upon which its action depends is that a block of 

 copper cooled by immersion in ice and salt will retain its low 

 temperature sufficiently long in order to enable sections to be cut 

 from a small piece of any soft tissue placed upon it, and which by 

 contact with it has become frozen and adherent to its surface. 

 If first immersed in gum water the specimens solidified better. 



In the discussion that followed, Mr. Ward suggested using a 

 metal plug in the same way as Dr. Pritchard recommended, only 

 dropping it into an ordinary microtome tube, so as to obtain the 

 additional advantage of a rest for the razor. 



Mr. Groves thought that if the plug were hollowed so as to 

 contain some ice and salt it would remain cold much longer. 



Acari in diabetic urine. — Mr. Jabez Hogg showed a specimen 

 of urine from a case of incipient diabetes which contained large 

 quantities of the Acarus domesticus, as well as particles of indigo. 

 Twenty-four hours after being voided he observed their presence, 

 and up to the present time they were still alive and breeding 

 (for they were seen in all stages of development), though six 

 weeks had elapsed. The mycelium of the diabetic fungus had 

 appeared and the indigo was increasing. It was possible that 

 the animal fed on these two substances. He had only examined 

 this one specimen, and had kept it in the bottle in which it had 

 been sent to him, in the window all the time. He had no doubt 

 it was the ordinary sugar acarus, and must have obtained access 

 to the urine in the first instance by accident. 



