SCIENTIFIC SUMMARY, 
435 
astronomer Pingre was living there, the solitaires had become so rare that 
he knew of them only from report — none having been seen by him. The 
extinction of the birds probably went on rapidly between 1730 and 1760, as 
may be inferred from the documents at the Ministers de la Marine. The 
land-tortoises became extinct somewhat later. These tortoises were part of 
the regular provisions of the shipping of the Compagnie des Indes. M. 
Desforge-Boucher, in his reports to the company in 1759 and 1760, enume- 
rates the vessels sent for the land-tortoises, and shows that they took away 
in less than eighteen months over 30,000. It is not surprising,” the author 
remarks, “ that these animals, on so small an island, notwithstanding their 
fecundity, could not withstand such means of destruction. Hungry man 
was the agent of extermination both for the tortoises and the birds.” These 
gigantic land-tortoises, while extinct on the islands of Mauritius, Rodri- 
guez, and Reunion, are living on that of Aldabra, another of the Mascarene 
Group. But there is danger of its extinction there. To prevent this, if 
possible, a memorial has been addressed to the Governor and Commander- 
in-Chief of Mauritius and its dependencies, signed by the presidents of the 
Royal and Royal Geographical Societies of London and other men of 
science, calling the attention of the Colonial Government to the subject, and 
asking that some means may be devised for ct saving the last examples of a 
contemporary of the dodo and solitaire.” 
An Improved Mode of Preserving the Bodies of Animals has been devised 
by Professor A. E. Verrill, and is described by him in u Silliman’s 
American. Journal ” (Sept. 1875). He says : — u During the summer nume- 
rous experiments were made by Professor W. N. Rice and the writer, to 
ascertain the effects of various chemical preparations upon marine inverte- 
brates. The special objects were: First, to improve the methods of pre- 
serving specimens for museum purposes, or to devise new methods j second, to 
ascertain the best means of killing in an expanded state species that ordinarily 
contract badly when put directly into alcohol. Besides numerous negative 
results, several of value were obtained. Numerous very perfect and beautiful 
preparations of Actinice (chiefly Metridium marginatum ), in a state of nearly 
complete expansion, were made by slowly adding a saturated solution of 
picric acid to a small quantity of sea water, in which they had been allowed 
to expand. When fairly dead they were transferred to a pure saturated 
solution of the acid, and allowed to remain from one to three hours, accord- 
ing to size, &c. They were then placed in alcohol of about 60 to 70 per 
cent, for permanent preservation. The alcohol should be renewed after a 
day or two, and this should be repeated until the water is all absorbed from 
the specimen. Hydroids ( Tubularice thus preserved are especially beautiful) 
and most kinds of jelly-fishes can be easily and beautifully preserved in the 
same way, but with these the specimens may usually be placed alive 
directly into the acid, of full strength. Even delicate ctenophorse ( Mnemi - 
opsis, Idyia, &c.) can be thus preserved so as to make fair specimens. With 
osrnic acid we did not succeed so well, for the specimens contracted more, 
and finally became so darkly stained as to render them useless. Hydro- 
chloral was also experimented with. It proved to be useless as a permanent 
preservative of marine invertebrates, as it apparently had a caustic or solvent 
F F 2 
