162 



THE AMEEICAN MONTHLY 



[September, 



of granular protoplasm, and contain- 

 ing a number of bright, strongly re- 

 fractive globular particles. It is the 

 Beggiatoa alba of Voucher. The 

 filaments are branched, either dicho- 

 tomously or laterally, and the cells 

 are frequently remarkably constrict- 

 ed, both above and below the septa. 

 The globular refringent particles 

 have been determined by German 

 experimenters to consist of pure sul- 

 phur, and are most commonly situ- 

 ated immediately below each septum, 

 but sometimes towards the centre of 

 a cell, or more generally diffused. 



' The systematic position of Beg- 

 giatoa is somewhat obscure. Topf 

 places it without hesitation among 

 the lowest section of fungi, the schi- 

 zomycetes, which form one division 

 of Sachs' primary class of protophyta. 

 It may, in fact, be regarded as the 

 leptothrix condition of an organism 

 of this class, having also its corre- 

 sponding bacillus, coccus, and spi- 

 rillum conditions. On the other 

 hand, it appears to be closely, allied 

 to the oscillatoria through Creno- 

 thrix. The source of the globules of 

 sulphur contained in this organism is 

 a very interesting question. The 

 Beggiatoa is not necessarily indica- 

 tive of partially decomposed sewage ; 

 it occurs also in the effluent water 

 from manufactories, especially sugar 

 factories and tanneries, etc., thermal 

 sulphur springs, as well as in drains. 

 It appears, therefore, to have the 

 power of extracting sulphur, not only 

 from decomposing organic matter, 

 but also from the mineral sulphates 

 dissolved in spring water. Sulphur 

 may be set free in this way by the 

 mutual decomposition of soluble sul- 

 phides and sulphites. Independently 

 of the source of sulphur is the organic 

 matter present in the sewage itself. 

 There is an abundant supply of this 

 element in the substances used for 

 purifying or precipitating the sew- 

 age, which are usually sulphate of 

 alumina, lime, and protosulphate of 

 iron. The growth of the so-called 

 sewage fungus must undoubtedly. 



therefore, be regarded as evidence of 

 the presence in the water of an ab- 

 normal amount of sulphates, derived 

 either directly from sewage or the 

 substances used in precipitating it, or 

 in other ways in manufactories. But 

 there seems no reason to believe that 

 it will itself have any injurious effects 

 on the water. It is difficult to see 

 how the sulphur, once set free, can 

 again combine with hydrogen to form 

 sulphui'etted hydrogen gas, as long as 

 the organism is growing in the water. 

 Indeed, if allowed to accumulate and 

 periodically removed, it may tend to 

 purify the water by abstracting from 

 it some of the undue proportion of 

 sulphur.' 



Dr. Dallinger and Professor Latti- 

 more briefly discussed the paper, em- 

 phasizing the necessity of making 

 such researches as that described in 

 Mr. Bennett's paper. 



William J. Lewis, of Hartford, 

 read the following paper on ' Hair, 

 Microscopically Examined and Med- 

 ico-legally Considered :' — 



' In the field of forensic medicine, 

 however, we necessarily must regard 

 the microscope as being in the in- 

 fancy of its service. I need only re- 

 mind you that in this branch of ovn* 

 work no one subject, probably, has 

 received such careful and thorough 

 study as that of blood-stains ; and yet, 

 after years of pains-taking research 

 and experiment — years of attentive 

 labor by many of the brightest lights 

 whose names and whose works have 

 illumined the annals of science — let 

 me ask who, at the present day, aided 

 by the most accurate instruments at 

 our command, is able and willing to 

 enter the witn-^ss box and swear, 

 without reserve, that a certain stain 

 which has been submitted to him for 

 an examination was made by human 

 blood .-^ If, then, in stains existing 

 under many varying conditions and 

 circumstances, but which are readily 

 demonstrated to be blood, we are yet 

 unable to distinguish human from 

 animal blood with absolute certaint}'. 

 we see how important it becomes to 



