The analysis of food and drugs / by T.H. Pearmain and C.G. Moor.

  • Thomas Hames Pearmain
Date:
1897-1899
Catalogue details

Licence: Public Domain Mark

Credit: The analysis of food and drugs / by T.H. Pearmain and C.G. Moor. Source: Wellcome Collection.

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    Naviciila radiosa (18); Navicula viridis (19).—These diatoms are motile, and contain chlorophyll of a dark yellow colour. ■1 20. mum) 21. 18. 19. 21. 22. Oscillaria (20) ; Nostoc (21).—These organisms, which are anaboena, form bluish-green or brownish patches. They are chiefly found in stagnant water ; and as they produce a disagreeable smell in water, their presence is very objectionable on this account, and because they in- dicate the presence of a large amount of organic matter. Pediastrum (22).—It contains chlorophyll, and is found in pond-water. Protococcus viridis (23).—This is a very common inhabitant of streams and rivers, and probably assists in their self-purifica- tion. It propagates by fission, and is generally seen in groups of four. Scenedesmus (24).—This organism is common in ponds, but does not appear to possess any hygienic importance; it contains chlorophyll. 24. Spirogyra (25). — This organism contains chlorophyll, in spiral bands, and starch granules. It is a com- mon inhabitant of ponds and streams. Staurastrum gracile (26).—This organism is one of the commonest desmids, and its presence in water is not objectionable—in fact, it is stated that it can only live in pure water which is well aerated and exposed to the light. 23. 25.
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