198 EMBRYOLOGY IN THE SEVENTEENTH [pt. 11 



various kinds : but he nowhere gives any indication of his percentage 

 hatch. It was probably low. He speaks also of the ^^funestes effets'^ 

 of the vapours of the dung on the developing embryos, without, how- 

 ever, furnishing any foundation for an exact teratology. In the second 

 volume he describes those experiments on the preservation of eggs 

 by varnishing them, which caught the imagination of Maupertuis 

 and were held up to an immortal but by no means deserved ridicule 

 by Voltaire in his Akakia. For the details of this amusing but 

 irrelevant issue see Miall and Lytton Strachey. 



After Reaumur, there were numerous continuations of the kind of 

 work which he had done, in particular by Thevenot, La Boulaye, 

 Nelli, Porta and Cedernhielm. Much the most interesting of these 

 was the work of Beguelin, who attempted to incubate eggs with 

 part of the shell removed so as to form a round window. He was not, 

 however, successful in the carrying out of this very modern idea. 

 Probably the most peculiar investigation made in this field at this 

 time was that of Achard, who is mentioned in a passage of Bonnet's. 

 "Reaumur did not suspect in 1749", says Bonnet, "that someday 

 one would try to substitute the action of the electric fluid for his 

 borrowed heat. This beautiful invention was reserved for M. Achard 

 of the Prussian Academy who excels as an experimentalist. He has 

 not so far succeeded in actually hatching a chick by means of so new 

 a process, but he has had one develop up to the eighth day, when 

 an unfortunate accident deranged his electrical apparatus." Bonnet 

 goes on to say that this substitution of electricity for heat gives him 

 hope that by electrical means an artificial fertilisation will one day 

 become possible. 



The references to these experiments and to those of many minor 

 investigators will be found in Haller. By the beginning of the nine- 

 teenth century a great mass of literature had developed on the 

 subject, and it had become possible to hatch out eggs more or less 

 successfully from furnaces, though the losses were still great. Early 

 in the nineteenth century Bonnemain and Jouard referred to the 

 large number of monsters produced, and in 1809 Paris wrote, 

 "During the period that I was at College, the late Sir Busick Har- 

 wood, the ingenious Professor of Anatomy in the University of 

 Cambridge, frequently attempted to develope eggs by the heat of 

 his hotbed, but he only raised monsters, a result which he attributed 

 to the unsteady application of the heat". 



