Tracts on the nature of animals and vegetables.

  • Spallanzani, Lazzaro, 1729-1799.
Date:
1799
Catalogue details

Licence: Public Domain Mark

Credit: Tracts on the nature of animals and vegetables. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    35/430 (page 19)
    with landing the cold killed the animalcula of feveral infnfions, there were fome more robuft fpecies that lupported it. I took the advantage of a very cold day; and, although the thermo- meter fell to 150 under the freezing point, and the infufions were covered with ice ; upon breaking it, and prefenting fome minute por- tions to the microfcope, I found living animal- cula in the parts not completely congealed. They were immured in little grottoes of ice. In thofe portions abfolutely frozen, the ani- malcula were dead. They did not revive up- on melting the ice. The refl retained their vi- vacity in the parts of the fluid not yet congeal- ed8. I could not decide whether the animal- cula perifli, becaufe the cold has deflroyed them, or becaufe the infufions have loft their fluidity. It is a fa£t acknowledged by philofophers, that water does not lofe its fluidity at 20, or even 220 below freezing, when at perfect reft ; which may be attained by inclufion in a clofe veffel, and removal from external motion. In this way, the animalcula furvived, although they fuftered cold almoft 20° below zero, in water not frozen. They fwam about, but with a flower motion than ufual, while the thermo- C 2 meter a Mr Muller of Copenhagen has clifcovered fome fpe- cies of animalcula which furvive congelation. I regret that his vfhrk did not come to my knowledge until the tranferip- tion of my mnnufeript was finilhed.