66 Dr. A. Ransome. On certain Conditions that [Dec. 18, 



paramitoma of the liver cells the following anaplastic and kataplastic 

 products may be demonstrated easily : serous fluid (vacuoles) bile 

 pigment, pigment containing iron, glycogen, fat, <fec. 



[It is to be remembered that, soon after the discovery of lobules in 

 the pig's liver by Wepfer (1664), Malpighi (1666) described these 

 lobules as being appended to the extremities of the vessels contained 

 in Glisson's capsule. Ferrein (1749) showed that the liver, like other 

 glands of the body, had a tubular structure ; but, as he included the 

 spleen among the tubular glands, it may be doubted whether he did 

 more than generalise on the basis of his observations on the kidney. 

 Three years before the publication of Kiernan's paper, Miiller seems 

 to havo noticed the pinnate arrangement to which I have given the 

 name of "portal lines of divergence;" but there can be little doubt as 

 to the general acceptance of Kiernan's views after the publication of 

 his observations in 1833 (' Philosophical Transactions '). The work 

 of Kiernan was in great part based on the result of injections through 

 the vessels. 



For an account of the history of the subject, 1 would refer the 

 reader to Kiernan's admirable paper, in which a great many points 

 which I have purposely left aside will be also found mentioned. 

 Dec, 17, 1890.] 



IV. " On certain Conditions that modify the Virulence of the 

 Bacillus of Tubercle." By ARTHUR RANSOME, M.D., F.R.S. 

 Received November 29, 1890. 



It is acknowledged by most pathologists that tubercular sputum, 

 dried up and broken into dust, is the most common vehicle by which 

 the bacillus of tubercle is conveyed into the body. 



But its power for evil is obviously modified by a multitude of 

 conditions, some of them inherent in the animal body exposed to 

 infection, others due to external influences. Judging from the facts 

 relating to the distribution of tubercular disease, its incidence in 

 certain localities, and especially its prevalence in badly drained, 

 badly ventilated, and imperfectly lighted dwellings, it has been 

 surmised that the three chief external conditions that mitigate the 

 virulence of the bacillus are : (1) a dry soil (2) abundance of fresh 

 air, and (3) light. 



But hitherto, few, if any, direct experiments have been made to 

 determine the extent to which these several influences possess 

 mitigating powers. 



It is time that Dr. Candler, in his work on the Prevention of Con- 

 sumption, affirms that light is the chief agent in destroying the 



