62 Transactions. — Miscellaneous. 



cites the investigations of Wood and Forniad, two American 

 physicians of the highest standing, in relation to an outbreak 

 of croup in 1881 at Ludington, a small town on the borders of 

 Lake Michigan. The principal industries carried on there 

 were derived from the neighbouring forests, an immense 

 quantity of the trees of which had been sawn into planks in 

 numerous sawpits within the area of the town. The greater 

 portion of the town stands on a height, but one quarter is 

 built on low marshy ground, which has been partly filled up 

 with sawdust. In this quarter the soil is so saturated with 

 moisture that when a small hole is dug it fills with water 

 immediately, and consequently cellars ai'e unknown. It was 

 in this quarter that the epidemic broke out, and was most 

 severe, almost all the children having been attacked by it, and 

 not less than a third of them having actually died. When 

 Wood and Formad began tlieir investigations Formad went to 

 Ludington to study the epidemic and collect materials for 

 experiments. In all the cases of croup he found the blood 

 full of micrococci belonging to Micrococcus diphthcricus — some 

 detached, others united in the form of zoogloea — that is, 

 agglutinated in small masses, — and others, again, in the 

 colourless corpuscles of the blood. All the organs, and 

 •especially the kidneys, were likewise filled with them. With 

 the materials which he gathered he and Wood made experi- 

 ments in cultures, and were able to inoculate rabbits with 

 croup. These inoculations were made subcutaneously \n the 

 muscles and trachea, and were followed by the production of 

 false mendiranes, the animals soon dying with all symptoms 

 of diphtheria, and the blood provmg to be full of micrococci. 

 An examination of living animals showed that the micrococcus 

 first attacked the colourless corpuscles, within which their 

 vibratile motion could be observed. The corpuscles changed 

 in appearance, the granules disappeared, and each corpuscle 

 became so full of the micrococci that they could no longer 

 move. In fact, the micrococci grew until they caused the 

 rupture of the corpuscle, and then escaped in the form of an 

 irregular mass, which constituted tlie zoogloea. Corpuscles 

 filled with micrococci were found in the false membrane, in 

 the small vessels — which they dilated and completely oblite- 

 rated — and even in the marrow of the bones. Cultures made 

 in flasks aflbrded important results. A comparison of the 

 sowings made with micrococci collected at Ludington with 

 those found in the ordinary diphtheritic angina, (then and still 

 common at Philadelphia,) showed a great difference in the 

 vitality and virulent properties of microbes derived from these 

 two sources. The former multiplied rapidly and energetically, 

 succeeding each other up to the tenth generation ; while those 

 from Philadelphia only went to the fourth or fifth generation, 



