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those of Borelli that show the astonishing force with which the stomachs of fowls and 



ducks pulverize empty globules of glass in the space of a few hours I 



conceived the design of extending them to birds with muscular stomachs and gizzards 

 then to animals with membranous stomachs .... not neglecting 

 man, the noblest and most interesting of all." 



The work contains six dissertations with two hundred and sixty- 

 four paragraphs, each one following the other with logical precision, 

 and giving exact accounts of the order of experimentation, the results, 

 and Spallanzani's deductions from them. Every student of medicine 

 should read the dissertations. 



I can, perhaps, best sum up Spallanzani's work by epitomizing 

 the letter of the veteran Professor A. v. KOLLIKER written " in 

 honour of the great Lazzarus Spallanzani." 



" In connection with the physiology of reproduction, I regard the following as the 

 chief contributions of Spallanzani : (1) He by means of beautiful experiments, if not 

 absolutely proving, at least made exceedingly probable the view that protozoa which 

 develope in infusions, only do so when it is possible for germs to pass into them from 

 the air. (2) He proved that the tail and limbs of tritons could be reproduced. In 

 1764 he had observed that snails could reproduce even their head if it was cut off. He 

 also made important discoveries by artificial impregnation of the ova of amphibia. His 

 observations on spermatozoa, and especially those with the filtered fluid, showed that the 

 spermatozoa alone are the fertilizing male element a fact which remained unconfirmed 

 until it was again proved in 1824 by Prevost and Dumas. The most important, how- 

 ever, was the artificial impregnation of a bitch, a fact confirmed by Professor P. Rossi 

 in Pisa in 1782." 



" Dealing with Spallanzani's observations on digestion, the most important points 

 are : (1) The digestive juice alone digests, and the muscular apparatus has no direct 

 influence on digestion. (2) He obtained natural gastric juice by introducing sponges 

 attached to strings into the stomachs of living animals, and in the same way obtained 

 the fluid of the crops in birds. (3) He made experiments outside the body with the 

 juice thus obtained, and showed its activity. (4) He also experimented with his own. 

 gastric juice and on his own digestive processes. (5) He made an enormous number of 

 experiments of a comparative nature on the most different animals, frogs, salamanders, 

 snakes, fish, &c. ; on the action of the gastric juice on all possible kinds of food, animal 

 and vegetable, bone, <fec. (6) Lastly he obtained a large quantity of gastric juice from a 

 crow, on which his friend Scopoli was able to make the first chemical analysis of this 

 fluid." 



His remarkable observations on Respiration, which bridged over 

 a great gap left by Lavoisier, are referred to in another place. 



In the same year as Spallanzani published his Opitscoli, a thesis 

 for the degree of M.D. was presented to the University of 

 Edinburgh by E. STEVEXS, De alimenlorum concoctione Diss. (Edin. 

 1777). This is translated and appended to the Dissertation of 

 Spallanzani already referred to. 



" The experiments were made at Edinburgh upon a Hussar, a man of weak 

 understanding, who gained a miserable livelihood by swallowing stones for the 

 amusement of the common people. He began this practice at the age of seven, and has 



